Multiphoton abosrpton method using patterned light

专利摘要:
A method and apparatus for making a material region in which a photoreactive composition is at least partially reacted. The method includes providing a photoreactive composition, providing a light source of sufficient light to simultaneously absorb two or more photons by the photoreactive composition, and providing an exposure system capable of inducing multiphoton absorption according to the image. Generating a pattern of non-random 3-dimension light by the exposure system, the 3-dimension produced by the exposure system to at least partially react with some material corresponding to the non-random 3-dimension incident light pattern Exposing the photoreactive composition to a pattern of light.
公开号:KR20030076237A
申请号:KR1020027017153
申请日:2001-06-14
公开日:2003-09-26
发明作者:플레밍패트릭알；데보로버트제이；스테이시니콜라스에이；리테르달캐더린에이；데마스터로버트디；발렌토드에이；플로르작제프리엠
申请人:쓰리엠 이노베이티브 프로퍼티즈 캄파니；
IPC主号:

专利说明:

Multi-photon absorption method using patterned light {MULTIPHOTON ABOSRPTON METHOD USING PATTERNED LIGHT}
[2] The two-photon absorption of the molecule was foreseen in 1931 by Goppert-Mayer. According to the pulsed ruby laser invention of 1960, experimental observation of two-photon absorption was realized. Subsequently, two-photon excitation has been applied in biological and optical data storage as well as other fields.
[3] There are two important differences between two-photon-induced photoprocesses and single photon-induced processes. Single photon absorption changes linearly with the intensity of incident radiation, while two photon absorption changes with a quadratic function. Large absorbance changes with the associated large force of the incident intensity. As a result, the multi-photon process can be performed with 3-dimensional spatial decomposition. In addition, since the multiphoton process involves simultaneous absorption of two or more photons, each photon has insufficient energy to excite the chromophores individually, but many of the same photoexcited state energy and total energy of the multiphoton photoresist used are the same. Photons of excitation absorbing chromophores. Exciting light is not attenuated by single photon absorption in the curable matrix or material, so that by using a beam focused at a depth within the material, it can be selectively placed deeper in the material than is possible through single photon excitation. The molecule can be excited. These two phenomena also apply to excitation, for example in tissues or other biological substances. However, this work has been limited to slow recording speed and high laser power. Thus, there is a need for a method of improving the performance and efficiency of a multiphoton absorption system. In multiphoton lithography or stereolithography, the nonlinear correlation of the intensity of absorption is not only the ability to record characteristics with a magnitude less than the diffraction limit of light, but also the ability to record characteristics in 3-dimensions (this is also of interest for holography). ).
[1] The present invention relates to multiphoton absorption methods and patterns for producing polymerizable three-dimensional structures.
[201] 1A illustrates a micro optical member exposure system of the present invention.
[202] FIG. 1B illustrates another embodiment of a micro optical member exposure system having microlenses of varying focal lengths.
[203] Figure 1C illustrates another embodiment that includes an arrangement of aspherical, non-axis microlenses.
[204] Figure 2 illustrates a diffractive optical member exposure system of the present invention using a beam splitting diffractive optical member (DOE).
[205] 3 illustrates another embodiment of a diffractive optical member exposure system in which a wavehead modified DOE is used.
[206] 4 is an exposure system that combines split spherical and aggregated plane waves to create an interference pattern in a photoreactive composition.
[207] FIG. 5 illustrates an embodiment of an exposure system that includes a combination of three or more beams having the same or substantially different heads to cause multiphoton absorption to be caused by selected regions in the photoreactive composition.
[208] FIG. 6 illustrates a system that includes an array of adjustable planar mirrors used to adjust the beam from the array of microlenses to the photoreactive composition.
[209] 7 is a scanning electron micrograph of the structure occurring under the test conditions of Example 2. FIG.
[210] FIG. 8 shows an exposure system used in Example 3 including an array of diffractive lenses.
[211] 9 is a scanning electron micrograph of the structure produced under the imaging conditions of Example 3. FIG.
[212] 10 is a scanning electron micrograph of the structure produced under the imaging conditions of Example 3. FIG.
[213] 11 is an optical micrograph of the structure produced under the imaging conditions of Example 4. FIG.
[214] 12 is an optical micrograph of a refractive index contrast image.
[4] Summary of the Invention
[5] The present invention provides various methods and apparatus for creating regions of at least partially reacted material in photoreactive compositions. In one embodiment, the method comprises providing a photoreactive composition, providing a source of light sufficient to simultaneously absorb two or more photons by the photoreactive composition, at least one diffractive optical member (preferably beamsplitting (beam diffraction optical member that enables beamsplitting, wave deformation or both), wherein the exposure system is an exposure system capable of causing multiphoton absorption according to the image. Generating a non-random 3-dimensional light pattern by means of, wherein the 3-dimensional light pattern generated by the exposure system to at least partially react some material corresponding to the non-random 3-dimensional pattern of incident light Exposing the photoreactive composition to the composition. "Responsive" does not require the reacted material to exactly copy the light pattern of the three dimensions, but accurate copying is possible.
[6] In another embodiment, a method of creating a region of at least partially reacted material in a photoreactive composition comprises providing a photoreactive composition, providing a source of sufficient light for simultaneous absorption of two or more photons by the photoreactive composition. Providing an exposure system comprising an array of one or more refractive micro optical members, wherein the exposure system is an exposure system capable of causing multiphoton absorption according to the image. Generating a light pattern of the polymer, exposing the photoreactive composition to the three-dimensional light pattern produced by the exposure system to at least partially react some material corresponding to the non-random three-dimensional pattern of incident light. Include.
[7] In another embodiment, the method comprises providing a photoreactive composition, providing a sufficient source of light for simultaneous absorption of two or more photons by the photoreactive composition, an exposure system capable of causing multiphoton absorption according to the image. Wherein the exposure system comprises a first beam of light having a first wave shape and a second beam of light having a second wave shape, wherein the first wave shape is substantially different from the second wave shape. Providing an exposure system. The method generates a non-random three-dimensional light pattern by an exposure system that uses optical interference between the beam of first light and the beam of second light, corresponding to the non-random three-dimensional pattern of incident light. Exposing the photoreactive composition to a three-dimensional light pattern produced by the exposure system to at least partially react the material.
[8] In another embodiment, a method of creating at least partially reacted material regions in a photoreactive composition comprises providing a photoreactive composition, providing a source of sufficient light for simultaneous absorption of two or more photons by the photoreactive composition, Providing an exposure system capable of causing multiphoton absorption according to the image, wherein the exposure system comprises at least three beams of light, each beam of light of the at least three beams of light having a shaped wavehead, the other beam of light And having a head shape that is the same as or substantially different from the head shape thereof. The method includes generating a non-random 3-dimensional light pattern by an exposure system that uses optical interference from at least three light beams, at least partially extracting some material corresponding to the non-random 3-dimensional pattern of incident light. Exposing the photoreactive composition to a three-dimensional light pattern produced by the exposure system for reaction.
[9] Various systems are provided for practicing various methods of the present invention. In one embodiment, a photoreactive composition, a source of light sufficient to simultaneously absorb two or more photons by the photoreactive composition, one or more diffractive optical members (preferably, beamsplitting, wave deformation or both) are possible Device for reacting a photoreactive composition comprising an exposure system comprising a diffractive optical member), wherein the exposure system can cause multiphoton absorption according to the image and is non-random, three-dimensional light pattern. And at least partially react some material corresponding to a non-random 3-dimensional pattern of incident light.
[10] In another embodiment, an apparatus for reacting a photoreactive composition includes an exposure system comprising a photoreactive composition, a source of light sufficient to simultaneously absorb two or more photons by the photoreactive composition, and an arrangement of one or more refractive micro-optical members. Wherein the exposure system is capable of causing multiphoton absorption according to the image and can produce a non-random 3-dimensional light pattern, and at least some material corresponding to the non-random 3-dimensional pattern of light. It can be reacted partially.
[11] In another embodiment, the present invention includes a photoreactive composition, a source of light sufficient to simultaneously absorb two or more photons by the photoreactive composition, a first beam of light including a first wave shape and a second wave shape. An exposure system comprising a beam of second light, wherein the first wavehead shape is substantially different from the second wavehead shape, the exposure system can cause multiphoton absorption according to the image, and is non-random, three-dimensional. A device for reacting a photoreactive composition, capable of generating a light pattern of, and capable of reacting at least partially some material corresponding to a non-random three-dimensional pattern of light.
[12] In another embodiment, an apparatus for reacting a photoreactive composition comprises a photoreactive composition, a source of light sufficient to simultaneously absorb two or more photons by the photoreactive composition, an exposure system comprising at least three light beams Each light beam of the three or more light beams includes a shaped wavehead, has a wave shape that is the same or substantially different from that of other light beams, and the exposure system can cause multiphoton absorption according to the image, Light patterns of non-3-dimensional, non-random 3-dimensional patterns of light, and at least partially react with some materials corresponding to non-random 3-dimensional patterns of light.
[13] Preferably the light source is a pulsed laser and the exposure comprises pulsed irradiation, preferably using a near infrared pulsed laser having a pulse length of less than about 10 nanoseconds.
[14] Preferably the photoreactive composition comprises at least one reactive species, at least one multiphoton photosensitizer, at least one electron donor compound and at least one photoinitiator. More preferably, the photoreactive composition comprises from about 5% to about 99.79% by weight of the at least one reactive species, from about 0.01% to about 10% by weight of the at least one multiphoton photoresist, based on the total weight of solids About 10% or less by weight of the electron donor compound, and about 0.1% to about 10% by weight of one or more photoinitiators.
[15] Term Definition
[16] As used herein, "multiphoton absorption" means the simultaneous absorption of two or more photons to reach a reactive electron excitation state that is actively inaccessible by absorption of a single photon of the same energy.
[17] "Simultaneous" means two or more events that occur for a period of 10 ^-14 seconds or less.
[18] An "electron excited state" means an electron state of a molecule that is higher in energy than the electron bottom state of the molecule, that is, a state accessible by absorption of electromagnetic waves and having a life time of 10 ^-13 seconds or more.
[19] "Reaction" means to perform depolymerization or other reactions as well as curing (polymerization and / or crosslinking).
[20] “Optical system” means a system for controlling light, wherein the system includes at least one member selected from refractive optical members such as lenses, reflective optical members such as mirrors, diffractive optical members such as gratings and computer-generated holograms do. Optical members may include diffusers, waveguides, and other members known in the art.
[21] "Exposure system" means an optical system plus a light source.
[22] "Enough light" means light of sufficient intensity and adequate wavelength to enable multiphoton absorption.
[23] By "photosensitive agent" is meant a molecule that lowers the energy required to activate the photoinitiator by absorbing light of less energy than the photoinitiator requires for activation and interaction of the photoinitiator to generate the photoinitiating species.
[24] The "photochemically effective amount" (of the photoinitiator system component) is determined by the reactive species under selected exposure conditions (as evidenced, for example, by changing density, viscosity, color, pH, refractive index or other physical or chemical properties). It is meant an amount sufficient to allow at least a partial reaction to be carried out.
[25] "Transit" means light that passes completely through a large amount of photoreactive composition.
[26] "Focusing" or "focusing" means collecting light at a point or forming an image of an object.
[27] By "wave" is meant the surface of a continuous phase on a propagating electromagnetic field, for example light emitted from a point source has a spherical wave.
[28] "Substantially different" applied to two or more waves indicates how the coherent electromagnetic beams will interact when combined. When the optical system used to generate the interference pattern is rearranged so that the beams are colinear (overlapping and have parallel propagation directions), the interference pattern formed by the combination of the beams may produce a region of interest in a given image plane. The crossing will create an interference fringe of at least one light and one darkness. This suggests that the wavehead differs at least half wavelength between the beams in this region.
[29] Detailed Description of the Preferred Embodiments
[30] Conventional techniques for exposing single photon photolimiting (eg photocurable) materials usually use a light source that fills a large area consistent with a reflective or opaque mask to select the exposed area. In addition, the optical member can be incorporated into the exposure system to perform projection lithography that will provide micron sized features. Typically, in a projection system, the image in the mask is small in size, light in the image plane is collected, and the influence of the light is uniform over the exposed area. A second conventional technique is to directly "record" an image using a laser light source, for example suitable optics. In this case, the actual pattern is in a computer file and the image is recorded directly by the computer controlled stage and laser system. The laser spot size is reduced by the optical member to show the precise characteristics of the pattern.
[31] Multiphoton processes typically require a relatively high light influence with pulse lengths of nanoseconds, thus providing a significant number of photons in the initiation region. The influence of high light can be achieved by focusing high energy laser light using a relatively high numerical aperture (NA) lens, for example a microscope objective lens. High NA provides shallow focus and produces good z-axis control of the multiphoton absorption process. The three-dimensional object can be fabricated by moving the laser source accurately in the x-y-z direction to form the reacted material in the desired shape. However, this technique can be slow and the accuracy of the technique will be limited by the accuracy of movement of the mechanical members.
[32] Large area exposure of multiphoton absorbing (eg curable) materials may enable faster fabrication of large objects. It is known that a photopolymerization mask, which is characteristic of projection optics, may not have a z-axis that focuses on the properties needed to form complex shapes in three dimensions. The present invention discloses the use of a mask arrangement wherein the light transmissive region can include a refractive member, such as light, to provide adequate z-axis definition. By way of example, a mask having a focusing feature may be made of photoresist defined by photolithography and may be melted to form one or more convex shapes comprising a predefined complex refractive structure.
[33] Other fabrication methods (eg, photolytic volume expansion of the glass, polymer droplet distribution, weight transfer, focused ion-beam milling, and other micro-optical fabrication methods known in the art) may require the refraction needed to provide proper z-axis confinement. It can also be used to make a surface.
[34] Examples of these refraction arrangements are shown in FIG. 1A, where the micro optical member exposure system 10 of the present invention is shown. As used herein, micro optical member means an optical member having an opening of 5 mm or less in at least one direction. Micro optics means optics having apertures less than about 6 mm in diameter. Fiber is often included in this category. For example, Newport Corp. See Irvine CA.'s catalog.
[35] As in FIG. 1A, the micro optical member exposure system 10 includes a photoreactive composition 20 and a micro optical member array 30. The micro optical member array 30 is used to focus the incident light 12 into the focus 40a-40e ("focal 40") to cause multiphoton absorption within the photoreactive composition 20. The micro optical member array 30 includes refractive microlenses 32a-32e (microlenses 32) and opaque portions 34a-34f (opaque portions 34). The opaque portion 34 does not allow the incident light 12 to pass through the micro optical member array 30 to the photoreactive composition 20. The microlens 32 refracts the incident light 12 and focuses it on the focal point 40. Moving the photoreactive composition 20 precisely in a direction parallel and perpendicular to the direction of illumination allows for simultaneous reaction of several identical structures. The width, depth, and orientation angles of the individual volume members produced within the photoreactive composition 20 illuminated by the microlenses 32 may be controlled by the appropriate design of the micro-optical member array 30 (eg, By incorporating off-axis, aspherical and amorphous surfaces),
[36] Likewise, the flat exposure arrangement of FIG. 1A can be extended to three dimensions by changing the focal length of the individual microlenses 32 in the micro-optical member array 30. Moreover, the micro-optical member need not be aligned in a regular arrangement, or need to have a unity fill factor.
[37] An example of a micro optical member exposure system 10 having microlenses 32 of various focal lengths is described in another embodiment in FIG. 1B. In FIG. 1B, the microlenses 132 of the micro-optical member array 130 have various focal lengths to focus incident light 112 at focal points 140 of varying depths within the photoreactive composition 120. For example, the microlens 132a has a shorter focal length than the microlens 132b, so that the focal point at the surface closer to the photoreactive composition 120 than the focal point 140b is the focal point 140b. At 140a, incident light 112 is focused.
[38] Simultaneous reaction (eg curing) of complex three-dimensional structures is also possible by incorporating beam-steering into the micron array. The three-dimensional structure is formed by reacting separate regions within physical contact but not overlapping with the focused light from each microlens. Figure 1c illustrates this concept as another embodiment of the present invention. In Fig. 1C, an aspherical array 230, non-axis microlenses 232 is shown. Each microlens 232 has a different focal length and the arrangement is used to react (eg, cure) with multiple nonoverlapping regions simultaneously at the focal points 240a-240e.
[39] Preferred methods of the present invention include the use of diffractive optical elements (DOE) to focus on high energy light, such as from an objective lens with a high numerical aperture but over a wide area in three dimensions. The function of the DOE can be divided into two categories: discrete array generation (beam splitting) of illuminated areas and generation of continuous illuminated areas of a particular shape (wave transform). A single DOE can perform two functions. The optical effect (shown in FIG. 2) of the beam splitting member is similar to that of the refractive microlens-continuous focus is created.
[40] In FIG. 2, the diffractive optical member exposure system 310 includes a photoreactive composition 320 and a diffractive optical member 330. DOE 330 diffracts beam of incident light 312 from photoreactive composition 320 to focal point 340. As in the case of refractive microlenses (see, eg, FIGS. 1A-1C), DOE 330 creates discrete focus 340.
[41] An important difference can occur between the methods in which usable light is used in the refractive and diffractive members. In the refractive member, only incident light on each microlens brings focus into the photoreactive composition (ie, the light between microlenses is not focused or reflected and does not contribute to the reaction (e.g. curing)). This is illustrated in FIG. 1A, where light 12 incident on opaque regions 34a-34e is not refracted to focus in photoreactive composition 20. In the case of diffraction, all of the incident light on the DOE is directed in a predetermined array pattern (if the member operates at high efficiency) (see for example FIG. 2). In addition, the effective NA of the DOE may be higher than the NA of the individual microlenses. Larger NAs give shallower depth of focus and provide better z-axis solutions.
[42] In addition, the focal point of the microlenses has a particular shape determined by diffraction from the confinement aperture (eg, a circular lens produces a circular Airy disc diffraction pattern). On the other hand, the beam splitting diffraction member can be designed to create a "focal spot" with a more general shape (e.g., square, rectangular, etc.). On the other hand, the wavehead modified diffraction optical member converts the incident light field into a more general and semi continuous pattern at a predetermined position.
[43] Figure 3 shows another embodiment of the present invention using a Padu modified DOE. As shown, the diffractive optical member exposure system 350 includes a wave modifier DOE 370 and a photoreactive composition 360. Incident light 352 is diffracted by DOE 370 in a semi-continuous random three-dimensional pattern 380.
[44] Both forms of DOE (beam splitting and wave deformation) are used to focus light from a broad incident beam into smaller spatial regions, causing a reaction (eg, curing) of the photoreactive composition. In the case where the diffractive member acts similarly to one or more refractive lenses (ie, when one or more discrete foci of small size are produced), the resulting focus pattern may have similar depth of focus characteristics as achieved by the refractive lens. (Depending on the DOE design method). When a complex light pattern is created through wave deformation, the behavior of the light field at a location away from the image plane becomes more complicated. In specific cases (eg, long narrow patterns), the depth of focus resulting from the DOE can be different in two directions perpendicular to the optical axis. This property can be used to be an advantage in forming certain structures.
[45] One possible method (for paraxial) that can be used to design a DOE includes an iterative Fourier deformation algorithm that mimics light field propagation between the plane of the diffractive member and the image plane. Certain light field amplification distributions in the image plane and manufacturing limitations of the diffractive member serve as limitations to cause concentration of the diffractive member design. (Other paraxial and non-paraxial methods useful for designing DOE are also known in the art). Typically, the complexity and resolution of a particular image formed by the diffractive member (as well as the efficacy of the diffractive member) is controlled by the method used to fabricate the diffractive member. The function of the optical phase calculated by the method is encoded in DOE, usually a surface-relief profile (although other methods can be used).
[46] The precise structure of the DOE has a significant effect on the usable optical efficiency (defined as percentage of incident light directed in a given area or direction). DOE typically consists of a surface-removal pattern in a transparent or reflective material having a multi-step profile close to the continuous profile determined from the design process. The efficiency of the DOE increases with the number of levels used for similar processes; Continuous profiles have the highest efficiency. The overall efficiency also depends on whether the calculated optical phase function used to form the DOE is limited so that it can be separated in the in-plane coordination system; Non-separable phase functions can have significantly higher diffraction efficiency. The minimum horizontal properties that can be made in the DOE fabrication process suggest an effective numerical aperture, which controls the minimum features that can be resolved in the DOE's image plane.
[47] The diffractive member may be fabricated by known methods (known as holograms) or by the structure of the surface removal profile, for example by forming and recording interference patterns of coherent (eg laser) light. The desired phase profile can be formed, for example, by selective chemical or physical etching at the material surface, by direct recording of the developable photopolymer (using an electron beam or laser) or through laser ablation. In all cases, the phase function recorded in the diffraction member changes the phase information of the incident light wavelength and orients the wavelength again in the predetermined direction.
[48] Previous examples of multiphoton absorption as holographic fabrication methods are disclosed (see, eg, TJBunning et al., Chem. Mater., 12, 2842 and C. Diamond et al., Opt . Express, 6 (3), 64). Interference between two beams with nearly identical wave shapes was used in the demonstration of both of them to form an interference pattern that reacted (cured) the photoreactive composition (and produced periodic reacted lines). In a first example, two gathered beams (not parallel or anti-parallel propagation directions) were incident on the photoreactive composition. In a second example, the two beams were combined to focus at the sample surface using separate portions of the same lens. In both cases, the two beams had almost the same wavehead and differed only in their propagation direction.
[49] The present invention discloses a combination of two beams having substantially different heads that cause multiphoton absorption in selected areas. The energy at the individual beams is insufficient to cause multiphoton absorption, but the energy at the interference maximum is sufficient to cause multiphoton absorption by the photoreactive composition. The use of two substantially different beams allows to generate an interference pattern, which does not constitute a regular arrangement.
[50] One embodiment of this configuration is shown in FIG. Here, the exposure system 410 combines the gathered planar wavelengths 420 and the scattered spherical wavelengths 430 to produce the interference pattern 440 in the photoreactive composition 450. The interference pattern 440 formed by the combination of these two beams 420 and 430 from the continuous wave light source is a series of concentric rings 442. In the short pulses used in multiphoton absorption, the exact matching of the two beam paths causes the overlap of pulses to form selected areas of the interference pattern. By carefully adjusting the path of one beam relative to another, it is possible to react different parts of the interference pattern with successive laser pulses. Although the present embodiment includes the simple case of plane and square waves combined with each other, various optical members can be placed on one beam so that part of the interference pattern has curved lines and / or lines that accurately shape each wave and change the periodicity. It is understood to produce the corresponding reacted region.
[51] The invention also discloses a combination of three or more beams having the same or substantially different heads to cause multiphoton absorption by the selected area. 5 shows one embodiment of this configuration. In FIG. 5, exposure system 460 includes incident light 470 and photoreactive composition 480 including light beams 472a, 472b, 472c, "light beam 472". Each light beam 472 includes aggregated plane waves 474 (ie plane waves 474a, 474b, and 474c). Plane wave 474 has a non-parallel propagation direction. Plane waves 474 are combined to form interference pattern 490 in photoreactive composition 480. The interference pattern 490 formed by the combination of these three light beams 472 is an array of intensity maximums in the grid arrangement 492. 5 shows the intensity maximum 492 in a particular plane, but the interference fringe occurs through three dimensions. For short pulses used in multiphoton absorption, the exact matching of the paths of the three beams 472 allows for the overlap of the pulses to form a selected region of the three-dimensional interference pattern 490. By carefully adjusting each beam path relative to the other beam, different portions of the interference pattern 490 can be reacted in successive laser pulses.
[52] Although this embodiment describes a simple case of three similar plane waves 474 used to generate the interference pattern 490, various optical members are placed on one or more of the three or more beams 472 to cover each wave. It is possible to create regions that are accurately shaped and reacted to complex three-dimensional patterns corresponding to the three-dimensional light patterns.
[53] Embodiments of the multiphoton absorption described above use only static refractive and diffractive optical members. The present invention can be extended by incorporating an active optical member into an optical system to enable dynamic control of the light pattern used to react the photoreactive composition.
[54] One embodiment thereof is shown in FIG. 6 where an array of adjustable planar mirrors 540 is used to adjust the beam 550 to the photoreactive composition 520 from the array of microlenses 530. Adjusting the angle of each mirror 540 may adjust the beam 550 to the selected non-overlapping volume of the photoreactive composition (ie, focal points 522a-522c).
[55] The present invention is not limited to optical elements incorporating the movable micromirrors described above, but adapts to any form of electronically configurable reflective, refractive or diffractive optical element, such as, but not limited to, polymer-dispersible liquid crystal lenses, adaptations. Members such as deformable mirrors and adjustable gratings commonly used in optical systems. Synchronization of the movement of the precise translation stage support with the signal and the photoreactive composition to control the operation of the adjustable optical member greatly reduces the total exposure time of the complex three-dimensional structure in the photoreactive composition.
[56] It is understood that a complete optical system is optimized to adjust the pulse width in the range of femtoseconds to nanoseconds. Light pulses of femtoseconds are on the order of micrometers and emphasize the importance of optical design (micro optics, diffraction or interference) to provide very small, complex three-dimensional structures.
[57] A system for multiphoton absorption includes an exposure system comprising a light source and a suitable optical member, and at least one reactive material, at least one multiphoton photosensitizer, optionally at least one electron donor compound, and optionally at least one photoinitiator for the photoreactive composition. It may include a photoreactive composition. Photoinitiators are usually optional except when the reactive species is a cationic resin.
[58] Exposure systems useful in the present invention include light sources, typically lasers, and suitable optical members. Laser light sources useful in the present invention are, for example, femtoseconds pumped by an argon ion laser (Coherent Innova 310) paired with a laser scanning confocal microscope (BioRad MRC600) equipped with a 0.75 NA objective (Zeiss 20X Fluar). And near infrared titanium sapphire oscillators (eg, Coherent 900-F). The laser (operating at 76 MHz) has a pulse width of 100 femtoseconds and is adjustable between 700 and 1000 nm with a bandwidth of 10 nm (fwhm). In practice, any suitable light source can be used that provides sufficient light energy at a wavelength suitable for the photoresist used in the photoreactive system (see below).
[59] Optical members useful in the present invention include, but are not limited to, refractive optical members, reflective optical members, diffractive optical members, diffusers, waveguides, and the like. The refractive optical member includes a lens, a mirror, a prism, and the like. Diffractive optical members include gratings, image masks, holograms, and the like. The reflective optical member includes a retro reflector, a focusing mirror, and the like. Many other optical members can be used as known to those skilled in the art. Examples include diffusers, Pockelsell, waveguides, wave plates, birefringent liquid crystals, and the like.
[60] Reactive species
[61] Reactive species suitable for use in the photoreactive composition include curable and non-curable species. Curable species typically include, for example, additive polymerizable monomers and oligomers and additional crosslinkable polymers (free radically polymerizable or crosslinkable ethylenically unsaturated species, such as, for example, acrylates, methacrylates and styrenes). Vinyl compounds), as well as cationic polymerizable monomers and oligomers and cationic crosslinkable polymers (these species are most commonly described as acids, including, for example, epoxides, vinylethers, cyanate esters, etc.) Mixtures and these are preferred.
[62] Suitable ethylenically unsaturated species are described, for example, in Palazzotto et al., US Pat. No. 5,545,676, column 1, line 65 to column 2, line 26 and include mono-, di-, poly-acrylates and methacrylates (eg, For example, methyl acrylate, methyl methacrylate, ethyl acrylate, isopropyl methacrylate, n-hexyl acrylate, stearyl acrylate, allyl acrylate, glycerol diacrylate, glycerol triacrylate, ethylene glycol di Acrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, 1,3-propanediol diacrylate, 1,3-propanediol dimethacrylate, trimethylolpropane triacrylate, 1,2, 4-butanetriol trimethacrylate, 1,4-cyclohexanediol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraa Relate, pentaerythritol tetramethacrylate, sorbitol hexaacrylate, bis [1- (2-acryloxy)]-p-ethoxyphenyldimethylmethane, bis [1- (3-acryloxy-2-hydroxy )]-p-propoxyphenyldimethylmethane, trihydroxyethyl-isocyanurate trimethacrylate, bis-acrylate and bis-methacrylate of polyethylene glycol having a molecular weight of about 200 to 500, US Pat. No. 4,652,274 Copolymerizable mixtures of acrylated monomers such as those disclosed herein, acrylate oligomers such as those disclosed in US Pat. No. 4,642,126); Unsaturated amides (eg methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, diethylene triamine tris-acrylamide and beta-methacrylaminoethyl methacrylate) ; Vinyl compounds (eg, styrene, diallyl phthalate, divinyl succinate, divinyl adipate and divinyl phthalate) and the like and mixtures thereof. Suitable reactive polymers include polymers having pendant (meth) acrylate groups, for example 1 to about 50 (meth) acrylate groups per polymer chain. Examples of such polymers include aromatic acid (meth) acrylate half ester resins such as Sarbox ^™ resins (eg, Sarbox ^™ 400, 401, 402,404 and 405) available from Sartomer. Other useful reactive polymers that are curable by free radical chemistry include polymers having a hydrocarbyl backbone and having pendant peptide groups having free radical polymerizable functionality attached thereto, such as described in US Pat. No. 5,235,015 to Ali et al. ). Mixtures of two or more monomers, oligomers and / or reactive polymers may be used as needed. Preferred ethylenically unsaturated species include acrylates, aromatic acid (meth) acrylate half ester resins, and polymers having pendant peptide groups with free radical polymerizable functionality attached to the hydrocarbyl backbone.
[63] Suitable cationic reactive species are described, for example, in Oxman et al., US Pat. Nos. 5,998,495 and 6,025,406 and include epoxy resins. Such materials are broadly referred to as epoxides, which include monomeric epoxy compounds and epoxides in polymer form and may be aliphatic, cycloaliphatic, aromatic or heterocyclic. These materials usually have an average of at least one polymerizable epoxy group per molecule (preferably at least about 1.5, more preferably at least about 2). The polymerizable epoxide is a linear polymer having terminal epoxy groups (eg diglycidyl ether of polyoxyalkylene glycol), a polymer having an oxirane monomer skeleton (eg polybutadiene polyepoxide) and pendant epoxy groups. Having polymers (eg, glycidyl methacrylate polymers or copolymers). The epoxide may be a pure compound or may be a mixture of compounds containing one or more epoxy groups per molecule. These epoxy containing materials can vary greatly depending on the nature of their backbones and substituents. For example, the backbone may be in any form and the substituents thereon may be any group that does not substantially interfere with cationic cure at room temperature. Examples of acceptable substituents include halogens, ester groups, ethers, sulfonate groups, siloxane groups, nitro groups, phosphate groups and the like. The molecular weight of the epoxy containing material may vary from about 58 to about 100,000 or more.
[64] Useful epoxy containing materials include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-2-methylcyclohexylmethyl-3,4-epoxy-2-methylcyclohexanecarbox And those containing cyclohexene oxide groups such as epoxycyclohexanecarboxylates exemplified by bixlate and bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate. A more detailed list of useful epoxides of these properties is described in US Pat. No. 3,117,099.
[65] Other epoxy containing materials useful include glycidyl ether monomers of the formula:
[66]
[67] Wherein R 'is alkyl or aryl and n is an integer from 1 to 6. Examples include the reaction of polyhydric phenols with chlorohydrins such as excess epichlorohydrin (eg, diglycidyl ether of 2,2-bis- (2,3-epoxypropoxyphenol) -propane). The glycidyl ether of polyhydric phenol obtained by making is mentioned. Further examples of this type of epoxide are described in US Pat. No. 3,018,262 and in the Epoxy Resin Handbook , Lee and Nerville, McGraw-Hill Book Co., New York (1967).
[68] Various commercial epoxy resins can be used. Specifically, readily obtainable epoxides are octadecylene oxide, epichlorohydrin, styrene oxide, vinyl cyclohexene oxide, glycidol, glycidyl methacrylate, diglycidyl ether of bisphenol A ( For example, Epon ^TM 828, Epon ^TM 825, Epon ^TM 1004, Epon ^TM 1010 from Resolution Performance Products, formerly Shell Chemical Co., as well as DER ^TM -331, DER ^TM -332, from Dow Chemical Co., Commercially available under the trade name DER ^TM -334), vinylcyclohexene dioxide (e.g., ERL-4206 from Union Carbide Corp.), 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexene carboxylate ( For example, Union Carbide Corp.'s ERL-4221 or Cyracure ^™ UVR 6110 or UVR 6105), 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methyl-cyclohexene carboxylate (E.g., ERL-4201 from Union Carbide Corp.), bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate (e.g. Er, ERL-4289 from Union Carbide Corp., bis (2,3-epoxycyclopentyl) ether (e.g. ERL-0400 from Union Carbide Corp.), aliphatic epoxy modified from propylene glycol (e.g., ERL-4050 and ERL-4052 from Union Carbide Corp.), dipentene dioxide (e.g., ERL-4269 from Union Carbide Corp.), epoxidized polybutadiene (e.g. Oxiron ^TM 2001 from FMC Corp.) , Silicone resins containing epoxy functionality, flameproof epoxy resins (e.g., brominated bisphenol type epoxy resins available from Dow Chemical Co., DER ^TM -580), 1,4-butanediol diol of phenolformaldehyde novolac Glycidyl ethers (eg, DEN ^TM -431 and DEN ^TM -438 available from Dow Chemical Co., Ltd.), resorcinol diglycidyl ether (eg Kopoxite ^{TM from} Koppers Company, Inc.) , Bis (3,4-epoxycyclohexyl) adipate (e.g., ERL-4299 or UVR-6128 from Union Carbide Corp.), 2- (3,4-epoxycyclo Sil-5,5-spiro-3,4-epoxy) cyclohexane-meth-dioxane (eg, ERL-4234 from Union Carbide Corp.), vinylcyclohexene monooxide 1,2-epoxyhexadecane (E.g., UVR-6216 from Union Carbide Corp.), alkyl C ₈ -C ₁₀ glycidyl ethers (e.g. Heloxy ^™ Modifier 7 from Resolution Performance Products), alkyl C ₁₂ -C ₁₄ glycidyl Ethers (e.g. Heloxy ^TM Modifier 8 from Resolution Performance Products), butyl glycidyl ethers (e.g. Heloxy ^TM Modifier 61 from Resolution Performance Products), cresyl glycidyl ethers (e.g. Resolution Performance Products Alkyl glycidyl ethers such as Heloxy ^TM Modifier 62), p-tert-butylphenyl glycidyl ether (e.g., Heloxy ^TM Modifier 65 from Resolution Performance Products), diglycidyl ether of 1,4-butanediol (for example, Heloxy Modifier 67 ^TM of Resolution Performance Products) polyfunctional glycidyl ethers, such as neopentyl Diglycidyl ether of glycol (e. G., The Heloxy ^TM Resolution Performance Products Modifier 68), cyclohexanedimethanol diglycidyl ether of di-methanol (for example, Heloxy ^TM Modifier of ResolutionPerformance Products 107), trimethylolethane triglycidyl Cydyl ether (e.g. Heloxy ^TM Modifier 44 from Resolution Performance Products), trimethylol propane triglycidyl ether (e.g. Heloxy ^TM Modifier 48 from Resolution Performance Products), polyglycidyl ether of aliphatic polyol (e.g. For example, Heloxy ^™ Modifier 84 from Resolution Performance Products, polyglycol diepoxide (eg, Heloxy ^™ Modifier 32 from Resolution Performance Products) bisphenol F epoxide (eg, GY-281 from Ciba-Geigy Corp. Or Epon ^™ -1138) and 9,9-bis [4- (2,3-epoxypropoxy) -phenyl] florenone (eg, Epon ^™ 1079 from Resolution Performance Products).
[69] Other useful epoxy resins include copolymers of acrylic acid esters of glycidol (eg, glycidyl acrylate and glycidyl methacrylate) with one or more copolymerizable vinyl compounds. Examples of such copolymers include 1: 1 styrene-glycidyl methacrylate, 1: 1 methyl methacrylate-glycidyl acrylate and 62.5: 24: 13.5 methyl methacrylate-ethyl acrylate-glycidyl methacrylate. There is acrylate. Other useful epoxy resins are known and include epoxides such as epichlorohydrin, alkylene oxides (eg propylene oxide), styrene oxides, alkenyl oxides (eg butadiene oxide) and glycine Cylyl esters (eg ethyl glycidate).
[70] Useful epoxy functional polymers include epoxy functional silicones, such as those described in US Pat. No. 4,279,717 to Eckberg, which can be obtained from General Electric Company. These are polydimethylsiloxanes in which 1-20 mole% of silicon atoms are substituted with epoxyalkyl groups (preferably epoxy cyclohexylethyl as described in US Pat. No. 5,753,346 to Kessel).
[71] Mixtures of various epoxy containing materials can also be used. Such mixtures may include two or more weight average molecular weight distributions of the epoxy containing compound [(low molecular weight (200 or less), medium molecular weight (about 200 to 10,000) and high molecular weight (about 10,000 or more)). In addition, the epoxy resin may comprise a mixture of epoxy containing materials having different chemical properties (eg, aliphatic and aromatic), functional (eg, polar and nonpolar) Other cationic reactive polymers (eg, vinyl ether, etc.) ) May be additionally incorporated if necessary.
[72] Preferred epoxides include aromatic glycidyl epoxy (eg, Epon ^™ resin from Resolution Performance Products) and cycloaliphatic epoxy (eg, ERL-4221 and ERL-4299 from Union Carbide Corp.).
[73] Suitable cationic reactive species also include vinyl ether monomers, oligomers and reactive polymers such as methyl vinyl ether, ethyl vinyl ether, tert-butyl vinyl ether, isobutyl vinyl ether, triethylene glycol divinyl ether (Rapi-Cure ^TM DVE-3, available from International Specialty Products, Wayne, NJ), trimethylolpropane trivinyl ether (available from TMPTVE, BASF Corp., Mount Olive, NJ), Vectomer ^TM divinyl ether resin from Allied Signal (e.g. , Vectomer ^™ 2010, Vectomer ^™ 2020, Vectomer ^™ 4010 and Vectomer ^™ 4020 and their equivalents available from other manufacturers) and mixtures thereof. Mixtures (optional ratios) of one or more vinyl ether resins and / or one or more epoxy resins may also be used. Polyhydroxy functional materials (such as those described in US Pat. No. 5,856,373 (Kaisaki et al.)) Can also be used in combination with epoxy- and / or vinyl ether-functional materials.
[74] Non-curable species include, for example, reactive polymers whose solubility can be increased with acid- or radical-derived reactions. Such reactive polymers include, for example, ester group-containing water-insoluble polymers that can be converted to water-soluble acid groups (eg, poly (4-tert-butoxycarbonyloxystyrene)) by photofabricated acids. Non-curable species are also described in chemically amplified photoresists (RDAllen, GM Wallraff, WDHinsberg and LLSimpson, "High Performance Acrylic Polymers for Chemically Amplified Photoresist Application" J.Vac.Sci.Technol.B. 9 , 3357 (1991)). ). The chemically amplified photoresist concept is now widely used for microchip fabrication, particularly for sub-0.5 micron (or sub 0.2 micron) properties. In such photoresist systems, catalytic species (typically hydrogen ions) can be produced by radiation, causing a cascade of chemical reactions. This cascade occurs when hydrogen ions initiate a reaction to produce more hydrogen ions or other acidic species, thereby amplifying the reaction rate. Examples of conventional acid catalyzed chemically amplified photoresist systems include deprotection (eg, TH-butoxycarbonyloxystyrene resists described in US Pat. No. 4,491,628, THP such as those described in US Pat. No. 3,779,778). Phenolic materials, tetrahydropyran (THP) methacrylate based materials, t-butyl methacrylate based materials such as those described in Proc. SPIE 2438 , 474 (1995) by RDAllen and the like); Depolymerization (eg, polyphthalaldehyde based materials); And rearrangements (eg, materials based on pinacol rearrangements).
[75] Useful non-curable species also include leuco dyes, which tend to be colorless until oxidized by the acid produced by the multiphoton photoinitiator system and exhibit a visible color once oxidized. (The oxidized pigments show color due to the absorption of light in the visible portion of the electromagnetic spectrum (about 400-700 nm).) The leuco dyes useful in the present invention can be oxidized or are reactive under intermediate oxidation conditions, Under conditions, they are not very reactive and do not oxidize. Many such chemical groups of leuco dyes are known to the ordinary chemist.
[76] Leuco dyes useful as the reactive species of the present invention include acrylated leucoazine, phenoxazine and phenothiazine, which may be represented in part by the formula:
[77]
[78] Wherein X is selected from O, S and -NR ¹¹ , S is preferred,
[79] R ¹ and R ² are independently selected from H and from 1 to about 4 alkyl groups, R ³ , R ⁴ , R ⁶ and R ⁷ are independently selected from H and from 1 to about 4 alkyl groups, Preferably methyl, R ⁵ is selected from 1 to about 16 carbon atoms of the carbon atom, 1 to about 16 alkoxy groups of carbon atoms and an aryl group of up to about 16 carbon atoms, and R ⁸ is -N (R ¹ ) Is selected from (R ² ), H, 1 to about 4 carbon atoms, wherein R ¹ and R ² are as described above and independently selected, and R ⁹ and R ¹⁰ are H and 1 to about carbon atoms. Independently selected from four alkyl groups, R ¹¹ is independently selected from from 1 to about 4 alkyl atoms of carbon atoms and from aryl groups of less than about 11 carbon atoms (preferably phenyl groups). The following compounds are examples of leuco dyes of these species.
[80]
[81] Kofichem II
[82]
[83] Other useful leuco dyes are Leuco Crystal Violet (4,4'4 "-methylidritris- (N, N-dimethylalanine)), Leuco Malachite Green (p, p'-benzylidenebis- (N, N-dimethyl) Aniline)), Leuco Atacryl Orange-LGM (Color Index Basic Orange 21, Comp.No.48035 (Fisher base compound)),
[84]
[85] Leuco Atacryl Brilliant Red-4G (Color Index Basic Red 14),
[86]
[87] Leuco Atacryl Yellow-R (Color Index Basic Yellow 11, Comp.No. 48055)
[88]
[89] Leuco Ethyl Violet (4,4 ', 4 "-methylidinetris- (N, N-diethylaniline), Leuco Victoria Blu-BGO (Color Index Basic Blue 728a, Comp.No. 44040; 4,4'-methyl Lidinbis- (N, N-dimethylaniline) -4- (N-ethyl-1-naphthalamine)), and LeucoAtlantic Fuchsine Crude (4,4 ', 4 "-methylidritris-aniline), It is not limited to this.
[90] The leuco dye (s) typically comprise at least about 0.01% by weight (preferably at least about 0.3% by weight, more preferably at least about 1% by weight, most preferably at least about 2 to 10% by weight) of the total weight of the photosensitive layer. May exist at the level. Other materials such as binders, plasticizers, stabilizers, surfactants, antistatic agents, coating aids, lubricants, fillers and the like may also be present in the photosensitive layer. Those skilled in the art will be able to readily determine the desired amount of additive. For example, the amount of filler is selected so that there is no unnecessary scatter at the recording wavelength.
[91] If desired, mixtures of different types of reactive species may be used in the photoreactive composition. For example, mixtures of free radical reactive species and cationic reactive species, mixtures of curable species and non-curable species, and the like are also useful.
[92] Photoinitiator system
[93] (1) multiphoton photosensitizer
[94] Multiphoton photosensitizers suitable for use in multiphoton photoinitiator systems of photoreactive compositions are capable of simultaneously absorbing two or more photons when exposed to sufficient light and fluorescein (ie 3 ', 6'-dihydroxyspiro [isobenzo Furan-1 (3H), greater than 9 '-[9H] xanthene] 3-one). Typically, the cross-sectional area is described in the J.Opt.Soc.Am.B, 13, 481 (1996) ( See Marder and Perry et al., International Publication WO 98/21521, 85 side line 18-22) by C.Xu and WWWebb As measured by one method, it may be at least about 50 × 10 ⁻⁵⁰ cm ⁴ seconds / photon.
[95] The method involves comparing the two-photon fluorescence intensity of the photosensitizer with the reference compound (under equivalent excitation intensity and photosensitizer concentration conditions). Reference compounds can be chosen to match the spectral ranges as closely as possible encompassed by photosensitizer absorption and fluorescence. In one possible experimental setting, the excitation beam can be divided into two arms, with 50% of the excitation intensity divided by the photosensitizer and 50% by the reference compound. The relative fluorescence intensity of the photosensitizer relative to the reference compound can then be measured using two photomultiplier tubes or other calibrated detectors. Finally, the fl fluorescence quantum efficiency of both compounds can be measured under one photon excitation.
[96] Methods of measuring fluorescence and phosphorescent quantum yields are known in the art. Typically, the region under the fluorescence (or phosphorescence) spectrum of the compound of interest is compared to the region under the fluorescence (or phosphorescence) spectrum of the standard luminescent compound having a known fluorescence (or phosphorescence) quantum yield and appropriate corrections are made (e.g. Optical intensity of the composition at the wavelength, the structure of the fluorescein detection device, the difference in the emission wavelength and the response of the detector to different wavelengths). Standard methods are described, for example, in IBBerlman, Handbook of Fluorescence Spectra of Aromatic Molecules , 2nd edition, pages 24-27, Academic Press, New York (1971); JNDemas and GACrosby, J. Phys. Chem. 75, 991-1024 (1971); JVMorris, MAMahoney and JRHuber, J. Phys. Chem. 80, are described in the 969-974 (1976).
[97] Assuming that the emission states are the same under one- and two-photon excitation (normal assumption), the two-photon absorption cross-sectional area of the photoresist, (δ _sam ), is equal to δ _ref K (I _sam / I _ref ) (φ _sam / φ _ref ) Where δ _ref is the two-photon absorption cross section of the reference compound, I _sam is the fluorescence intensity of the photosensitizer, I _ref is the fluorescence intensity of the reference compound, φ _sam is the fluorescence quantum efficiency of the photosensitizer, and φ _ref is the reference The fluorescence quantum efficiency of the compound, K is the correction factor that accounts for the two detector responses and the slight difference in the optical path. K can be determined by measuring the response with the same photosensitizer in both the sample and the reference arm. To assure valid measurements, one can confirm the apparent second-order dependence of the two-photon fluorescence intensity on the excitation power, and relatively low concentrations of both the sensitizer and the reference compound can be used (the effect of fluorescence resorption and sensitizer aggregation) To avoid).
[98] If the photosensitizer is not fluorescent, the yield of the electron excited state can be measured and compared with known standards. In addition to the above-described method for measuring fluorescence yield, various methods for measuring excited state yield are known (e.g., transient absorption, phosphorescence yield, photoproduct formation or disappearance of photoresist (from photoreaction), etc.).
[99] Preferably the two-photon absorption cross-sectional area of the photosensitizer is at least about 1.5 times greater than fluorescein (or alternatively, at least about 75 × 10 ⁻⁵⁰ cm ⁴ sec / photons, measured by the method described above), more preferably At least about 2 times (or alternatively, at least about 100 x 10 ^-50 cm ⁴ seconds / photons) fluorescein, and most preferably at least about 3 times, or at least about 150, fluorescein x ^10-50 cm ⁴ seconds / photon or more), optionally about 4 times or more (or alternatively, about 200 × ^10-50 cm ⁴ seconds / photon or more) of fluorescein.
[100] Preferably the photosensitizer is soluble in the reactive species (if the reactive species is a liquid), or is compatible with the reactive species and other conjugates included in the compositions (described below). Most preferably 2-methyl-4,6- under continuous irradiation (single photon absorption conditions) in the wavelength range superimposed on the single photon absorption spectrum of the photosensitive agent using the test method described in US Pat. No. 3,729,313. Bis (trichloromethyl) -s-triazine can also be photosensitized. Using currently available materials, the test can be conducted as follows.
[101] Standard test solutions can be prepared having the following composition: 5.0 parts of a 5% (w / v) solution in methanol of polyvinyl butyral (Butvar ^™ B76, Monsanto) with a hydroxyl content of 45,000-55,000 molecular weight, 9.0-13.0%. ; Trimethylolpropane trimethacrylate and 0.3 parts of 2-methyl-4,6-bis (trichloromethyl) -s- triazine 0.03 parts (Bull.Chem.Soc.Japan, 42, 2924 - Reference (1969) 2930) . To this solution can be added 0.01 part of the compound to be tested as a photosensitizer. The resulting solution can then be knife coated using a 0.05 mm knife orifice on a 0.05 mm transparent polyester film and the coating can be air dried for about 30 minutes. The 0.05 mm of transparent polyester cover film can be carefully placed so that the air content is minimal on a dry but soft sticky coating. The resulting sandwich structure can then be exposed for 3 minutes to incident light of 161,000 lux from a tungsten light source that provides light in the visible and ultraviolet range (FCH ^™ 650 Watt Quarters-Iodine Lamp, General Electric). The exposure may be through a stencil to provide exposed and unexposed areas in the structure. The cover film can be removed after exposure and the coating can be treated with finely divided colored powder (eg, color toner powder of the type commonly used in dry printing). If the compound tested is a photosensitizer, the trimethylolpropane trimethacrylate monomer is in the region exposed to light by the free radicals generated as light from 2-methyl-4,6-bis (trichloromethyl) -s-triazine. Will polymerize. Since the polymerized area will be substantially viscous, the colored powder is almost selectively attached only to the viscous, unexposed areas of the coating and provides a corresponding visual image in the stencil.
[102] Preferably, the photosensitizer may be selected in consideration of some storage stability. Thus, the choice of particular photosensitizer may vary to some extent depending on the particular reactive species used (as well as the choice of electron donor compound and / or photoinitiator).
[103] Particularly preferred multiphoton photosensitizers exhibit a large multiphoton absorption cross section, for example rhodamine B (ie N- [9- (2-carboxyphenyl) -6- (diethylamino) -3H-xanthene Hexafluoroantimonate salt of -3-ylidene] -N-ethylethanealuminum chloride and rhodamine B) and four described in WO 98/21521 and WO 99/53242, for example, Marder and Perry. Group of photosensitizers. The four groups can be described as follows: (a) a molecule linked to a π (pi) -electron bridge in which two donors are conjugated, (b) a conjugated π () in which two donors are substituted with one or more electron acceptors. pi)-a molecule linked to the electron bridge, (c) a π (pi) -linked molecule with two receptors conjugated and (d) a conjugated π (pi) with two receptors substituted with at least one electron donor group A molecule linked to an electron bridge, where "bridge" refers to a molecular fragment that connects two or more chemical groups, and a "donor" refers to an atom with a low ion potential that can be bound to a conjugated π (pi) -electron bridge or By atomic group, "receptor" means an atom or group of atoms having a high electron affinity that can be bonded to a conjugated [i] -electron bridge.).
[104] Representative examples of such preferred photosensitizers include:
[105]
[106]
[107]
[108]
[109]
[110]
[111]
[112] The aforementioned four groups of photosensitizers can be prepared under standard Wittig conditions or by reacting aldehydes with lides using a McMurray reaction (see International Patent Publication WO 98/21521).
[113] Other compounds have been described by Reinhardt et al. (Eg, US Pat. Nos. 6,100,405, 5,859,251 and 5,770,737) having large multiphoton absorption cross sections, but these cross sections were measured by methods other than those described above. Representative examples of such compounds include the following:
[114]
[115]
[116] Other compounds that may be useful as photosensitizers in the present invention include fluorescein, p-bis (o-methylstyryl) benzene, eosin, rose bengal, erythrosin, coumarin 307 (Eastman Kodak), cascade blue hydrazide trisodium salt , Lucifer Yellow CH Ammonium Salt, 4,4-Difluoro-1,3,5,7,8-pentamethyl-4-bora-3α, 4α-diazindacene-2,6-disulfonic acid disodium salt, 1 , 1-Dioctadecyl-3,3,3 ', 3'-tetramethyllindocarbocyanine perchlorate, indo-1 molecular probes, 5-dimethylaminonaphthalene-1-sulfonyl hydrazine, 4' , 6-Diamidino-2-phenyllindol dihydrochloride, 5,7-diiodo-3-butoxy-6-fluoron, 9-fluorenone-2-carboxylic acid and a compound having the structure Including but not limited to:
[117]
[118]
[119] (2) electron donor compound
[120] Electron donor compounds that can be used in the multiphoton photoinitiator system of the photoreactive composition are compounds (except for the photosensitizer itself) that can donate electrons to the electron excited state of the photosensitizer. The electron donor compound preferably has an oxidation potential of 0 or more and less than or equal to the oxidation potential of p-dimethoxybenzene with respect to the standard saturated red electrode. It is preferable that the oxidation potential is about 0.3 to 1 volt with respect to the standard saturated magenta electrode ("S.C.E").
[121] The electron donor compound is also preferably soluble in the reactive species and is selected in part in view of storage stability (as described above). Suitable donors can generally increase the phase density or reaction (cure) rate of the photoreactive composition upon exposure to light of the desired wavelength.
[122] Those skilled in the art will appreciate that when using cationic reactive species, the electron donor compound (if significantly basic) can adversely affect the cationic reaction (e.g., column 7 line 62 in column 6 of US Pat. No. 6,025,406 (Oxman et al.)). 8 see discussion on line 49].
[123] In general, electron donor compounds suitable for use with certain photosensitizers and photoinitiators can be selected by comparing the oxidation and reduction potentials of the three components (see, eg, US Pat. No. 4,859,572 (Farid et al.)). Such potentials can be measured experimentally (eg, by methods described in RJ Cox, Photographic Sensitivity , Chapter 15, Academic Press (1973)), or by NL Weinburg, Technique of Electroorganic Synthesis Part II Techniques of Chemistry , Vol. . V (1975) and by CK Mann and KK Barnes ( Electrochemical Reactions in Nonaqueous Systems (1970)). The potentials represent relative energy relationships and can be used in the following manner to assist in the electron donor compound selection.
[124] When the photosensitizer is in an electron excited state, the electrons in the most occupied molecular orbital (HOMO) of the photosensitizer are elevated to a higher energy level (ie, the lowest unoccupied molecular orbital (LUBO) of the photosensitizer) and the vacancy is the first occupied molecule. Is left on the orbital. Photoinitiators can accept electrons from higher energy orbitals and electron donor compounds can donate electrons to fill the voids of the initially occupied orbitals if certain relative energy relationships are satisfied.
[125] If the reduction potential of the photoinitiator is less negative (or a larger positive value) than the reduction potential of the photoresist, electrons in the higher energy orbital of the photoresist are easily transferred from the photoresist to the lowest unoccupied molecular orbital (LUMO) of the photoinitiator. Because it represents the process. Although this process is rather endothermic (ie, the reduction potential of the photosensitizer is a negative value up to 0.1 volts greater than the reduction potential of the photoinitiator) ambient thermal activation can easily overcome this small barrier.
[126] In a similar manner, electrons that move from the HOMO of the electron donor compound to the orbital vacancies of the photoconductor when the oxidation potential of the electron donor compound is less positive (or greater negative) than the oxidation potential of the photosensitizer It moves to a low potential, which also represents an exothermic process. Even if this process is a weak endothermic reaction (ie, the oxidation potential of the photosensitizer is a positive value up to 0.1 volts greater than the oxidation potential of the electron donor compound), ambient thermal activation can easily overcome this small barrier.
[127] Weak endothermic reactions where the reduction potential of the photosensitizer is a negative value up to 0.1 volts greater than the reduction potential of the photoinitiator, or the oxidation potential of the photosensitizer is a positive value up to 0.1 volts greater than the oxidation potential of the electron donor compound is a photoinitiator or electron donor compound This happens in all cases, regardless of whether they react first with the photosensitizer in this excited state. When the photoinitiator or electron donor compound reacts with the photosensitizer in an excited state, the reaction is preferably exothermic or only a weak endothermic reaction. If the photoinitiator or electron donor compound reacts with photosensitive ionic radicals, an exothermic reaction is still preferred, but in many cases more endothermic reactions can be expected to occur. Thus, the reduction potential of the photosensitizer may be a negative value up to 0.2 volts (or more) than the reduction potential of the second-to-react photoinitiator, or the oxidation potential of the photosensitizer is second-to-react. It may be a positive value up to 0.2 volts (or more) than the oxidation potential of the reactant electron donor compound.
[128] Examples of suitable electron donor compounds are described in DF Eaton, Advances in Photochemistry , B. Voman et al., Volume 13, pp. 427-488, John Wiley and Sons, New York (1986); US Patent No. 6,025,406 to Oxman et al. (Columns 7 lines 42-61); And US Pat. No. 5,545,676 to Palazzotto et al. (Column 4 row 14 to column 5 row 18). Such electron donor compounds include amines such as triethanolamine, hydrazine, 1,4-diazabicyclo [2.2.2] octane, triphenylamine [and triphenylphosphine and triphenylarcin analogs thereof], aminoaldehydes and amino Silanes), amides (e.g. phosphoamides), ethers (e.g. thioethers), urea (e.g. thioureas), sulfinic acid and salts thereof, salts of ferrocyanide, ascorbic acid and salts thereof, dithiocarbamic acid And salts thereof, salts of xanthic acid, salts of ethylene diamine tetraacetic acid, (alkyl) _n (aryl) _m borate (n + m = 4) (preferably tetraalkylammonium salts), various organometallic compounds such as SnR ₄ compounds Wherein each R is independently selected from alkyl, aralkyl (especially benzyl), aryl and alkaryl groups (e.g., nC ₃ H ₇ Sn (CH ₃ ) ₃ , (allyl) Sn (CH ₃ ) ₃ and ( Benzyl) Sn (compounds such as nC ₃ H ₇ ) ₃ ), ferrocene and the like and mixtures thereof. The electron donor compound may be unsubstituted or substituted with one or more noninterfering substituents. Particularly preferred electron donor compounds include electron donor atoms (eg, nitrogen, oxygen, phosphorus or sulfur atoms) and removable hydrogen atoms bonded to carbon or silicon atoms at the alpha position of the electron donor atom.
[129] Preferred amine electron donor compounds include alkyl-, aryl-, alkaryl- and aralkyl-amines (e.g. methylamine, ethylamine, propylamine, butylamine, triethanolamine, amylamine, hexylamine, 2,4-dimethylaniline , 2,3-dimethylaniline, o-, m- and p-toluidine, benzylamine, aminopyridine, N, N'-dimethylethylenediamine, N, N'-diethylethylenediamine, N, N'-dibenzyl Ethylenediamine, N, N'-diethyl-1,3-propanediamine, N, N'-diethyl-2-butene-1,4-diamine, N, N'-dimethyl-1,6-hexanediamine, Piperazine, 4,4'-trimethylenedipiperidine, 4,4'-ethylenedipiperidine, pN, N-dimethyl-aminophenethanol and pN-dimethylaminobenzonitrile); Aminoaldehydes (eg, p-N, N-dimethylaminobenzaldehyde, p-N, N-diethylaminobenzaldehyde, 9-julolidine carboxaldehyde and 4-morpholinobenzaldehyde); And aminosilanes (eg trimethylsilylmorpholine, trimethylsilylpiperidine, bis (dimethylamino) diphenylsilane, tris (dimethylamino) methylsilane, N, N-diethylaminotrimethylsilane, tris (dimethylamino) phenyl Silane, tris (methylsilyl) amine, tris (dimethylsilyl) amine, bis (dimethylsilyl) amine, N, N-bis (dimethylsilyl) aniline, N-phenyl-N-dimethylsilylaniline and N, N-dimethyl- N-dimethylsilylamine); And mixtures thereof. Tertiary aromatic alkylamines, especially compounds having one or more electron withdrawing groups on aromatic rings, have been found to provide particularly good storage stability. Excellent storage stability was also obtained using amines that were solid at room temperature. The use of amines containing one or more zoloridinyl moieties resulted in good photography speeds.
[130] Preferred amide electron donor compounds include N, N-dimethylacetamide, N, N-diethylacetamide, N-methyl-N-phenylacetamide, hexamethylphosphoramide, hexaethylphosphoramide, hexapropylphosphor Amides, trimorpholinophosphine oxides, tripiperidinophosphine oxides and mixtures thereof.
[131] Preferred alkylaryl borate salts
[132]
[133] Where Ar is phenyl, naphthyl, substituted (preferably fluorine substituted) phenyl, substituted naphthyl, and a group having a greater number of fused aromatic rings), as well as tetramethylammonium n-butyl Triphenylborate and tetrabutylammonium n-hexyl-tris (3-fluorophenyl) borate (commercially available as CGI 437 and CGI 746 from Ciba Specialty Chemicals Corporation) and mixtures thereof.
[134] Suitable ether electron donor compounds include 4,4'-dimethoxybiphenyl, 1,2,4-trimethoxybenzene, 1,2,4,5-tetramethoxybenzene and mixtures thereof. Suitable urea electron donor compounds include N, N'-dimethylurea, N, N-dimethylurea, N, N'-diphenylurea, tetramethylthiourea, tetraethylthiourea, tetra-n-butylthiourea, N , N-di-n-butylthiourea, N, N'-di-n-butylthiourea, N, N-diphenylthiourea, N, N'-diphenyl-N, N'-diethylthiourea And mixtures thereof.
[135] Preferred electron donor compounds for free radical induction reactions include amines, alkylarylborate salts and salts of aromatic sulfinic acids comprising one or more zoloridinyl moieties. However, the electron donor compound may be excluded for this reaction as needed (eg to improve the storage stability of the photoreactive composition or to change the resolution, contrast and interrelationship). Preferred electron donor compounds for the acid induction reaction are 4-dimethylaminobenzoic acid, ethyl 4-dimethylaminobenzoate, 3-dimethylaminobenzoic acid, 4-dimethylaminobenzoin, 4-dimethylaminobenzaldehyde, 4-dimethylaminobenzonitrile, 4-dimethylaminophenethyl alcohol and 1,2,4-trimethoxybenzene.
[136] (3) photoinitiator
[137] Suitable photoinitiators of the reactive species of the photoreactive composition are those that can accept electrons from the electron excited state of the multiphoton photosensitizer to form one or more free radicals and / or acids. Such photoinitiators include iodonium salts (e.g. diaryliodonium salts), methylated triazines (e.g. 2-methyl-4,6-bis (trichloromethyl) -s-triazine, 2,4,6- Optionally with groups such as tris (trichloromethyl) -s-triazine and 2-aryl-4,6-bis (trichloromethyl) -s-triazine), diazonium salts (e.g. alkyl, alkoxy, halo or nitro) Substituted phenyldiazonium salts), sulfonium salts (e.g. triarylsulfonium salts optionally substituted with alkyl or alkoxy groups and optionally having a 2,2'oxy group bridge near the aryl moiety), azinium salts (e.g., N-alkoxypyridies Nium salts) and triarylimidazolyl dimers (preferably 2,4,5-triphenylimidazolyl dimers such as 2,2 ', 4,4', 5,5'-tetraphenyl-1,1'- Biimidazole, which may optionally be substituted by groups such as alkyl, alkoxy or halo) and the like and mixtures thereof.
[138] The photoinitiator is preferably soluble in the reactive species and is preferably storage stable (ie, does not spontaneously promote the reaction of the reactive species when dissolved in the presence of the photosensitizer and electron donor compound). Thus, the choice of particular photoinitiator may vary to some extent depending upon the particular reactive species, photosensitizer and electron donor compound selected as described above. Preferred photoinitiators exhibit a large multiphoton absorption cross-sectional area, for example as described in PCT patent applications WO 98/21521 and WO 995/3242 and Goodman et al. PC 99 patent application WO 99/54784, such as Marder, Perry.
[139] Suitable iodonium salts include those described in columns 2 28-46 of US Pat. No. 5,545,676 to Palazzotto et al. Suitable iodonium salts are also disclosed in US Pat. Nos. 3,729,313, 3,741,769, 3,808,006, 4,250,053, and 4,394,403. Iodonium salt is a simple salt (for ^{example, Cl -, Br -, I} - or C ₄ H ₅ SO ₃ ^- salt containing the same anion as) or a metal complex salt (for _{^{example, SbF 6 -, PF 6 -}} , BF 4 - It may be a salt containing a) ^-, tetrakis (perfluoro phenyl) borate, SbF ₅ OH ^- or AsF _6. If necessary, a mixture of iodonium salts can be used.
[140] Examples of useful aromatic iodonium complex salt photoinitiators include diphenyliodonium tetrafluoroborate; Di (4-methylphenyl) iodonium tetrafluoroborate; Phenyl-4-methylphenyliodonium tetrafluoroborate; Di (4-heptylphenyl) iodonium tetrafluoroborate; Di (3-nitrophenyl) iodonium hexafluorophosphate; Di (4-chlorophenyl) iodonium hexafluorophosphate; Di (naphthyl) iodonium tetrafluoroborate; Di (4-trifluoromethylphenyl) iodonium tetrafluoroborate; Diphenyliodonium hexafluorophosphate; Di (4-methylphenyl) iodonium hexafluorophosphate; Diphenyliodonium hexafluoroarsenate; Di (4-phenoxyphenyl) iodonium tetrafluoroborate; Phenyl-2-thienyliodonium hexafluorophosphate; 3,5-dimethylpyrazolyl-4-phenyliodonium hexafluorophosphate; Diphenyliodonium hexafluoroantimonate; 2,2'-diphenyliodonium tetrafluoroborate; Di (2,4-dichlorophenyl) iodonium hexafluorophosphate; Di (4-bromophenyl) iodonium hexafluorophosphate; Di (4-methoxyphenyl) iodonium hexafluorophosphate; Di (3-carboxyphenyl) iodonium hexafluorophosphate; Di (3-methoxycarbonylphenyl) iodonium hexafluorophosphate; Di (3-methoxysulfonylphenyl) iodonium hexafluorophosphate; Di (4-acetamidophenyl) iodonium hexafluorophosphate; Di (2-benzothienyl) iodonium hexafluorophosphate; And diphenyl iodonium hexafluoroantimonate and the like and mixtures thereof. Aromatic iodonium complex salts are described in Beringer et al ., J. Am. Chem. Soc. 81 , 342 (1959)] can be prepared by metathesis of the corresponding aromatic iodonium simple salts (eg, diphenyliodonium bisulfate, etc.).
[141] Preferred iodonium salts include diphenyl iodonium salts (e.g. diphenyl iodonium chloride, diphenyl iodonium hexafluorophosphate and diphenyl iodonium tetrafluoroborate), diaryl iodonium hexafluoro Antimonates (eg, SarCat ^™ SR 1012 available from Sartomer Caompany) and mixtures thereof.
[142] Useful methylated triazines include those described in US Pat. No. 3,779,778 (Smith et al.), Columns 8, lines 45-50, including 2,4-bis (trichloromethyl) -6-methyl-s- Triazines, 2,4,6-tris (trichloromethyl) -s-triazines, more preferred are chromophore substituted vinylhalomethyl-s disclosed in US Pat. Nos. 3,987,037 and 3,954,475 (Bonham et al.) -Triazine.
[143] Useful diazonium salts include those disclosed in US Pat. No. 4,394,433 (Gatzke), which refers to external diazonium groups (-N ⁺ = N) and anions bound thereto (e.g. chloride, tri-isopropyl naphthalene sulfonate And photosensitive aromatic moieties (eg, pyrrolidine, morpholine, aniline and diphenyl amine) with tetrafluoroborate and bis (perfluoroalkylsulfonyl) methide). Examples of useful diazonium cations include 1-diazo-4-anilinobenzene, N- (4-diazo-2,4-dimethoxy phenyl) pyrrolidine, 1-diazo-2,4-diethoxy- 4-morpholino benzene, 1-diazo-4-benzoyl amino-2,5-diethoxy benzene, 4-diazo-2,5-dibutoxy phenyl morpholino, 4-diazo-1-dimethyl aniline , 1-diazo-N, N-dimethylaniline, 1-diazo-4-N-methyl-N-hydroxyethyl aniline, and the like.
[144] Useful sulfonium salts include those that may be represented by the formula shown in column 1 line 66 to column 4 line 2 of US Pat. No. 4,250,053 to Smith.
[145] or
[146] Wherein R ₁ , R ₂ and R ₃ are aromatic groups having from about 4 to about 20 carbon atoms (eg substituted or unsubstituted phenyl, naphthyl, thienyl and furanyl, wherein the substitution is alkoxy, alkylthio , Arylthio, halogen, and the like) and alkyl groups having 1 to about 20 carbon atoms. As used herein, "alkyl" includes substituted alkyl (eg, substituted with a group such as halogen, hydroxy, alkoxy or aryl). At least one of R ₁ , R ₂ and R ₃ is aromatic, preferably each independently aromatic. Z is a covalent bond, oxygen, sulfur, -S (= O)-, -C (= O)-,-(O =) S (= O)-and -N (R)-[R is aryl (carbon atom A number from about 6 to about 20, such as phenyl), acyl (from about 2 to about 20 carbon atoms, such as acetyl, benzoyl, etc.), a carbon-carbon bond, or-(R ₄ ) -C (- R ₅ )-[R ₄ and R ₅ are independently selected from the group consisting of hydrogen, alkyl groups having 1 to about 4 carbon atoms, alkenyl groups having about 2 to about 4 carbon atoms]. X ⁻ is an anion as described below.
[147] Anions X ⁻ suitable for sulfonium salts (and any other type of photoinitiator) include various anion types such as imides, metades, boron centers, phosphorus centers, antimony centers, arsenic centers and aluminum center anions.
[148] Non-limiting examples of suitable imide and metaide anions are
[149]
[150] There is this. Preferred anions of this type has the formula _{(R f SO 2) 3 C} - include compounds represented by _[f R is the alkyl radical being a perfluoroalkyl of 1 to about 4 carbon atoms.
[151] Non-limiting examples of suitable boron central anions include
[152]
[153] There is this. Preferred boron central anions generally comprise aromatic hydrocarbon radicals substituted with at least three halogens bonded to boron, with fluorine being the most preferred halogen. Non-limiting examples of the preferred anions include (3,5-bis _{(CF 3) C 6 H 3} ) 4 B -, (C 6 F 5) 4 B -, (C 6 F 5) 3 (nC 4 H 9) _{^{B -, (C 6 F 5}} ) 3 FB - and the like ^- and _{(C 6 F 5) 3 (} CH 3) B.
[154] Examples of suitable anions include other metal or metalloid center are (3,5-bis _{(CF 3) C 6 H 3} ) 4 Al -, (C 6 F 5) 4 Al -, (C 6 F 5) ^{_{2 F 4 P -, (C}} 6 F 5) F 5 P -, F 6 P -, (C 6 F 5) F 5 Sb -, F 6 Sb -, (HO) F 5 Sb - , and F ₆ As ^- There is. The above examples are only a few, and other useful anion containing other boron-centered non-nucleophilic salts and other useful anions containing other metals or semimetals will be readily apparent to those skilled in the art.
[155] Anion X ⁻ is combined with tetrafluoroborate, hexafluorophosphate, hexafluoroarsenate, hexafluoroantimonate and hydroxypentafluoroantimonate (e.g. cationic reactive species such as epoxy resins) It is preferable to select from).
[156] Examples of suitable sulfonium salt photoinitiators include
[157] Triphenylsulfonium tetrafluoroborate,
[158] Methyldiphenylsulfonium tetrafluoroborate,
[159] Dimethylphenylsulfonium hexafluorophosphate,
[160] Triphenylsulfonium hexafluorophosphate,
[161] Triphenylsulfonium hexafluoroantimonate,
[162] Diphenylnaphthylsulfonium hexafluoroarsenate,
[163] Tritolylsulfonium hexafluorophosphate,
[164] Anylsildiphenylsulfonium hexafluoroantimonate,
[165] 4-butoxyphenyldiphenylsulfonium tetrafluoroborate,
[166] 4-chlorophenyldiphenylsulfonium hexafluorophosphate,
[167] Tri (4-phenoxyphenyl) sulfonium hexafluorophosphate,
[168] Di (4-ethoxyphenyl) methylsulfonium hexafluoroarsenate,
[169] 4-acetonylphenyldiphenylsulfonium tetrafluoroborate,
[170] 4-thiomethoxyphenyldiphenylsulfonium hexafluorophosphate,
[171] Di (methoxysulfonylphenyl) methylsulfonium hexafluoroantimonate,
[172] Di (nitrophenyl) phenylsulfonium hexafluoroantimonate,
[173] Di (carbomethoxyphenyl) methylsulfonium hexafluorophosphate,
[174] 4-acetamidophenyldiphenylsulfonium tetrafluoroborate,
[175] Dimethylnaphthylsulfonium hexafluorophosphate,
[176] Trifluoromethyldiphenylsulfonium tetrafluoroborate,
[177] p- (phenylthiophenyl) diphenylsulfonium hexafluoroantimonate,
[178] 10-methylphenoxane hexafluorophosphate,
[179] 5-methylthianthrenium hexafluorophosphate,
[180] 10-phenyl-9,9-dimethylthioxanthium hexafluorophosphate,
[181] 10-phenyl-9-oxothioxanthium tetrafluoroborate,
[182] 5-methyl-10-oxotianthrenium tetrafluoroborate,
[183] 5-methyl-10,10-dioxothioanthrenium hexafluorophosphate is mentioned.
[184] Preferred sulfonium salts include triaryl substituted salts such as triarylsulfonium hexafluoroantimonate (e.g. SarCat ^TM SR1010 available from Sartomer Company), triarylsulfonium hexafluorophosphate (e.g. available from Sartomer Company) SarCat ^™ SR1011), and triarylsulfonium hexafluorophosphate (eg, SarCat ^™ K185 available from Sartomer Company).
[185] Useful azinium salts include those described in column 8 51 to column 9 46 of US Pat. No. 4,859,572 (Farid et al.), Including azinium moieties such as pyridinium, diazinium, or triazinium moieties. Included. The azinium moiety may comprise one or more aromatic rings, typically carbocyclic aromatic rings (eg, quinolinium, isoquinolinium, benzodiazinium and naphthodiazonium moieties) fused with an azinium ring. The quaternized substituents of nitrogen atoms in the azinium ring can be dissociated as free radicals when electrons are transferred from the electron excited state of the photosensitizer to the azinium photoinitiator. In a preferable embodiment, the quaternized substituent is an oxy substituent. The oxy substituent -OT which quaternizes the ring nitrogen atom of an azinium part can be selected from the various oxy substituents which are easy to synthesize | combine. The T moiety can be, for example, an alkyl radical such as methyl, ethyl, butyl and the like. Alkyl radicals may be substituted. Aralkyl (eg benzyl and phenethyl) and sulfoalkyl (eg sulfomethyl) radicals may be useful. In another form T may be an acyl radical, such as an —OC (O) —T ¹ radical, where T ¹ may be any of the various alkyl and aralkyl radicals described above. In addition, T ¹ may be an aryl radical such as phenyl or naphthyl. Aryl radicals may also be substituted. For example T ¹ may be a tolyl or xylyl radical. T generally contains 1 to about 18 carbon atoms, preferably in each case the alkyl moiety is a lower alkyl moiety, and in each case preferably the aryl moiety contains about 6 to about 10 carbon atoms. The highest activity was realized when the oxy substituent -OT- contained 1 or 2 carbon atoms. The azinium nucleus need not contain substituents other than quaternized substituents. However, the presence of other substituents does not adversely affect the activity of these electron acceptor compounds.
[186] Useful triarylimidazolyl dimers include those described in columns 8, lines 18-28 of US Pat. No. 4,963,471 (Trout et al.). Examples of such dimers include 2- (o-chlorophenyl) -4,5-bis (m-methoxyphenyl) -1,1'-biimidazole; 2,2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetraphenyl-1,1'-biimidazole; And 2,5-bis (o-chlorophenyl) -4- [3,4-dimethoxyphenyl] -1,1'-biimidazole.
[187] Preferred photoinitiators include iodonium salts (more preferably aryliodonium salts), methylated triazines, triarylimidazolyl dimers (more preferably 2,4,5-triphenylimidazolyl dimers), sulfonium salts And diazonium salts. More preferred are aryliodonium salts, methylated triazines and 2,4,5-triphenylimidazolyl dimers, with aryliodonium salts and triazines being most preferred.
[188] Preparation of Photoreactive Compositions
[189] Reactive species, multiphoton photosensitizers, electron donor compounds and photoinitiators can be prepared by the methods described above or by other methods known in the art, many of which are commercially available. These four components are formulated under any "safe light" conditions (optionally stirring or shaking) using any combination order and manner, but it is often desirable to add photoinitiators last (in terms of shelf life and thermal stability). (And then optionally use any heating step to promote dissolution of other components). Solvents may be used as needed, provided that the solvents are selected so as not to react significantly with the components of the composition. Examples of suitable solvents include acetone, dichloromethane and acetonitrile. The reactive species itself may often act as a solvent for other components.
[190] The components of the photoinitiator system are present in photochemically effective amounts (as described above). Generally, the composition comprises at least about 5% by weight, preferably at least about 10% by weight, more preferably at least about 20% by weight of one or more reactive species. Generally the composition comprises up to about 99.79% by weight, preferably up to about 95% by weight, more preferably up to about 80% by weight. Generally, the composition comprises at least about 0.01% by weight, preferably at least about 0.1% by weight, more preferably at least about 0.2% by weight of one or more photosensitizers. The composition generally comprises at least about 10% by weight, preferably at most about 5% by weight, more preferably at most about 2% by weight of one or more photosensitizers. Preferably at least about 0.1% by weight of one or more electron donor compounds. Preferably the composition comprises at least about 10%, preferably at most about 5%, by weight of at least one electron donor. Preferably the composition comprises at least about 0.1% by weight of at least one photoinitiator. Preferably the composition comprises about 10% by weight, more preferably about 5% by weight or less of one or more photoinitiators. When the reactive chemical species is a leuco dye, the composition typically contains at least about 0.01% by weight, preferably at least 0.3% by weight, more preferably at least about 1% by weight, most preferably at least about 2% by weight of at least one leuco dye. It may include. If the reactive species is a leuco dye, the composition may generally comprise up to about 10% by weight of one or more leuco dyes. These are based on the total weight of the solid, ie the total weight of the components other than the solvent.
[191] Various adjuvants may be included in the photoreactive composition depending on the desired properties. Suitable auxiliaries include solvents, diluents, resins, binders, plasticizers, pigments, dyes, inorganic or organic reinforcing or extending fillers (preferred amounts of from about 10 to 90% by weight, based on the total weight of the composition), thixotropic agents, reaction indicators, inhibitors , Stabilizers, ultraviolet absorbers, pharmaceuticals (eg, porous fluorides), and the like. The amount of such adjuvants and the manner in which they are added to the composition and composition are well known to those skilled in the art.
[192] It is within the scope of the present invention to include non-reactive polymer binders in the composition, such as to control viscosity and provide film forming properties. Such polymeric binders may generally be selected to be compatible with the reactive species. For example, a polymeric binder may be used that is soluble in the same solvent as used for the reactive species and free of functional groups that may adversely affect the reaction process of the reactive species. The binder may have a molecular weight suitable for obtaining the desired film forming properties and solution flowability (eg, about 5,000 to 1,000,000 Daltons, preferably about 10,000 to 500,000 Daltons, more preferably about 15,000 to 250,000 Daltons). Examples of suitable polymeric binders include polystyrene, poly (methyl methacrylate), poly (styrene) -co- (acrylonitrile), cellulose acetate butyrate, and the like.
[193] Prior to exposure, the formed photoreactive composition can be coated onto the substrate, if desired, by any of a variety of coating methods known to those skilled in the art (eg, knife coating and spin coating). Substrates can be selected from a wide range of films, sheets and other surfaces depending on the particular application and the exposure method employed. It is preferable that the substrate is generally flat enough to produce a layer of photoreactive composition having a uniform thickness. For applications where the need for a coating is low, the photoreactive composition may be exposed alternately in bulk form.
[194] Exposure system and its use
[195] Useful exposure systems include one or more light sources (usually pulsed lasers) and one or more optical members. An example of a suitable light source is a titanium sapphire vibrator (eg, Coherent Mira Optima 900-F) in the vicinity of ^10-15 seconds infrared light, pumped by an argon ion laser (eg, coherent innova). The laser operates at 76 MHz, has a pulse width of less than 200 x 10 ^-15 seconds, can be tuned from 700 to 980 nm, and average power is less than 1.4 watts. In practice, however, any light source can be used that provides sufficient intensity at a suitable wavelength for the photoresist (used in the photoreactive composition) (to cause multiphoton absorption). Such wavelengths may generally range from about 300 to about 1500 nm, preferably from about 600 to about 1100 nm, more preferably from about 750 to about 850 nm. Peak intensity may generally be at least about 10 ⁶ W / cm ² . The upper limit of pulse influence (energy per pulse per unit area) is generally determined by the flux threshold of the photoreactive composition. For example Q-switched Nd: YAG lasers (e.g. Spectra-Physics Quanta-Ray PRO), visible wavelength dye lasers (e.g. Spectra-Physics Sirah pumped by Spectra-Physics Quanta-Ray PRO), and Q- Switched diode pumped lasers (eg Spectra-Physics FCbar ^™ ) can also be used. Preferred light sources are near infrared pulse lasers having a pulse length of less than about 10 nanoseconds (more preferably less than about 1 nanosecond, most preferably less than about 10 picoseconds). Other pulse lengths may be used if the above peak intensity and pulse influence criteria are met.
[196] Optical members useful for carrying out the method of the invention include reflective optical members (e.g. lenses and prisms), reflective optical members (e.g. retroreflectors or focus mirrors), diffractive optical members (e.g. diffraction gratings, image masks and holograms) , Diffusers, Pockels cells, waveguides, wave plates, birefringent liquid crystals, and the like. Such optical members are useful for focusing, beam delivery, beam / mode shaping, pulse shaping and pulse timing. In general, combinations of optical members may be used, and other suitable combinations will be appreciated by those skilled in the art. It may often be desirable to use optical members with multiple effective apertures to provide high focus light. However, any optical member combination can be used that provides the desired intensity profile (and its spatial arrangement). For example, the exposure system may include a scanning confocal microscope (BioRad MRC600) equipped with a 0.75 NA objective (Zeiss 20X Fluar).
[197] In general, the exposure of the photoreactive composition can be performed using a light source (as described above) in conjunction with an optical system as a means for controlling the three-dimensional spatial distribution of light intensity in the composition. For example, light from the pulsed laser can pass through the focus lens such that the focus is in the volume of the composition. The focus can be scanned or deformed in a three-dimensional pattern corresponding to the desired shape to form a three-dimensional image of the desired shape. The exposed or illuminated volume of the composition can be scanned by moving the composition itself or by moving the light source (eg, by moving the laser beam using a galvanometer).
[198] If the light induces a reaction of the reactive species, for example producing a substance with different solubility properties from the reactive species, the resulting phase is exposed or unexposed through the use of a suitable solvent, such as through other means known in the art. It can be selectively developed by removing. Complex three-dimensional objects can be prepared in this manner.
[199] Exposure time is generally the type of exposure system used to induce phase formation (and additional variables such as the number of effective apertures, the shape of the light intensity spatial distribution, the peak light intensity during the laser pulse duration [larger intensity and shorter The pulse duration is largely consistent with the peak light intensity]) as well as the nature of the exposed composition (and the concentration of the photosensitizer, the photoinitiator concentration and the concentration of the electron donor compound). In general, the higher the peak light intensity in the focal region, the shorter the exposure time and everything else is the same. Linear phase-forming or “writing” rates are about 10 ⁻⁸ to 10 ⁻¹⁵ seconds (preferably about 10 ⁻¹¹ to 10 ⁻¹⁴ seconds) and about 10 ² to 10 ⁹ pulses / second of laser pulse duration. (preferably about 10 ^{8 3-10} pulses / sec) when it can generally be from about 5-100000 microns / second using a.
[200] The features, aspects and advantages of the invention can be better understood with reference to the description, the claims and the drawings.
[215] The objects and advantages of the present invention will be explained in detail by the following examples, but the specific materials mentioned in the examples and their amounts as well as other conditions and details are not to be understood as unduly limiting the present invention. These examples illustrate the use of an optical member to create a three-dimensional shape in a photoreactive composition.
[216] Example 1
[217] This embodiment illustrates the use of a phase or diffraction mask to form a photopolymerizable region by a multiphoton absorption process.
[218] The calculation of the phase profile for the diffraction mask uses an input beam with uniform energy distribution. In this embodiment, to minimize the run time required for the calculation, a simple rectangular grid of lines, everything in one plane, is provided as a test pattern. The fabrication of the mask is carried out using conventional etching techniques and the mask has four phase levels to provide diffraction efficiency.
[219] The design of the image mask produces a series of focal points or lines in one plane with a focal length of 10 mm and an effective numerical aperture of 0.50. The series of focal lines produced by the mask form a rectangular grid with lines spaced in the x or y direction of 0.5 cm. The recording laser is an amplified titanium: sapphire laser delivering 750 mW from 1 kHz to 800 nm with a pulse width of 120 femtoseconds (fs). The TEM ₀₀ output from the laser enters an optical system that transforms the input Gaussian beam into a uniform energy distribution with a rectangular cross section of 0.1 cm x 10.1 cm. The influence per pulse in the plane of the image mask is 0.74 mj (milli Joules) per square centimeter (mj / cm ² ). The top mask was attached to a fixture spaced about 9.5 mm away from the bottom of the mask on the sample surface. Adjusting the mask mounting to micrometers allows the final focus position to match the top layer surface of the sample. The mask mounting and the sample stage move in writing with respect to each other. The rectangular beam from the laser hits the mask perpendicular to the mask plane, with the long axis of the beam parallel to the short axis of the mask. The laser beam is fixed for stage and mask movement.
[220] Test samples (comprised of refined glass wafers with an average surface roughness of 1.0 μm in thickness of 8 mm, diameter of 12.7 cm) provide a substrate for polymer coating. A thin film of methyl methacrylate monomer with a 4,4'-bis (diphenylamino) -trans-stilbene 1%, multiphoton initiator covers the refined surface of the glass wafer. The composition of this polymerizable coating was solid of 40% tris- (2-hydroxyethylene) isocyanurate triacrylate ester dissolved at 40% by weight in dioxane, 59% methyl methacrylate and 1% multiphoton absorbent. It consists of components. This polymeric material layer is about 100 μm thick. Exposure of the polymerizable coating on the covered glass wafer occurs by continuously moving the sample structure and the image mask along a direction parallel to the minor axis of the rectangular beam exiting the optical system. The sample stage moves uniformly at a speed of 100 μm / sec past the light source. While the light source scans the image mask, the line grid is photopolymerized in the polymerizable layer.
[221] The PMMA coating in dioxane is developed to remove unreacted areas from the glass wafer revealing the reacted (photocured) lines in the shape of a square grid. The individual lines forming the grid have a thickness of about 20 μm and a width of about 15 μm. The polymerizable line has good adhesion to the glass wafer.
[222] Example 2-6
[223] In the present embodiments, various different arrangements of optical member arrays have been used to produce multiple regions of material that have been at least partially reacted by multiphoton photopolymerization in a single exposure pass. Unless stated otherwise, the chemical was commercially available from Aldrich Chemical Co. Milwaukee, WI.
[224] A two-photon photosensitive dye, bis [4- (diphenylamino) styryl] -1,4- (dimethoxy) benzene, was prepared as follows: (1) 1,4-bis-bromomethyl-2,5 Reaction of dimethoxybenzene with triethyl phosphite (Horner Eamons reagent) ; 1,4-bis-bromomethyl-2,5-dimethoxybenzene was prepared according to the process described in the literature (Syper et al., Tetrahedron, 1983, 39,781-792). 1,4-bis-bromomethyl-2,5-dimethoxybenzene (253 g, 0.78 mol) was placed in a 1000 mL round bottom flask. Triethyl phosphite (300 g, 2.10 mol) was added. The reaction was heated to vigorous reflux with stirring for 48 h under a nitrogen atmosphere. The reaction mixture was cooled and excess P (OEt) ₃ was removed under vacuum using a Kugelrohr apparatus. Kugelrohr was used to remove excess P (OEt) ₃ by distilling from the product although the desired product was not actually distilled. Heating to 0.1 ° C. at 100 ° C. produced a clear oil. Cool to solidify the desired product. The product was suitable for direct use in the next step and the ¹ H NMR was consistent with the expected structure. Recrystallization from toluene yielded a colorless needle and produced in a more pure form, but in most cases this was not necessary for subsequent steps.
[225] (2) Synthesis of bis- [4- (diphenylamino) styryl] -1,4- (dimethoxy) benzene: A 1000 mL round bottom flask was fitted with a calibrated dropping funnel and magnetic stirrer. The flask was charged with the product prepared in the above reaction (Horner Eamons reagent) (19.8 g, 45.2 mmol) and N, N-diphenylamino-p-benzaldehyde (25 g, 91.5 mmol, Fluka). The flask was flushed with nitrogen and sealed with septa. Anhydrous tetrahydrofuran (750 mL) was cannulated into the flask and all solids dissolved. The dropping funnel was charged with potassium t-butoxide (1.0 M in THF, 125 mL). The solution in the flask was stirred and potassium t-butoxide solution was added into the contents of the flask for 30 minutes. The solution was then left to stir overnight at room temperature. Water (500 mL) was then added to stop the reaction. After about 30 minutes of continued stirring, a solid yellow solid was formed in the flask. The solid was separated by filtration, air dried and recrystallized from toluene (450 mL). The desired product was obtained in fluorescent needles (24.7, 81% yield). The ¹ H NMR spectrum of the product was consistent with the expected structure.
[226] The light source for Example 2-5 was a titanium: sapphire laser (Spectra-Physics) operating at wavelength 800 nm, pulse width about 100 fs, pulse repetition rate 80 MHz, beam diameter about 2 mm, and average output power 860 mW. It was a pumped diode. The optical train consisted of a low dispersion rotating mirror and an optical attenuator to change the optical power. The final focus member has been described in detail in each example. The movement of the sample or the movement of the sample and the final focus member was performed using a computer controlled stage with a motor from New England Affiliated Technologies, Inc. (Lawrence, Mass.).
[227] Photoreactive Composition I ingredientweight% Poly (methyl methacrylate) (MW approximately 120,000 g / mol)26.55 Tris (2-hydroxyethylene) isocyanurate triacrylate SR-368 (Sartomer Co., West Chester, PA)35.40 Alkoxylated Trifunctional Acrylate SR-9008 (Sartomer Co., West Chester, PA)35.40 CGI7460 (Ciba Specialty Chemicals, Tarrytown, NY)1.77 Daaryliodonium hexafluorophosphate, SR1012 (Sartomer Co., West Chester, PA)1.77 Bis- [4- (diphenylamino) styryl] -1,4- (dimethoxy) benzene0.88
[228] Example 2
[229] In Example 2, an array of fused silica microlenses (commercially available from MEMS Optical, Huntsville, AL) was used to split a beam that gathered into many focused points in the volume of the sample. The microlenses were aligned in a hexagonal array and had a fill factor of 70%. Each micro lens had a diameter of about 76 microns and the numerical aperture was 0.5. For this test substrate, a reaction (e.g. photocuring) was placed on a 70 μm thick wedge over the substrate such that the focus of each microlens was nearly coincident with the substrate / polymer interface (see FIG. 1A). Was performed.
[230] The test samples consisted of glass microscope slides pretreated with a 2% solution of trimethoxysilylpropylmethacrylate in aqueous ethanol as an adhesion promoter, followed by 46% solids in dioxane (Mallinckrodt Baker Inc., Phillipsburg, NJ). Spin coating with photoreactive composition I (Table 1) dissolved in solution. The coated slides were then calcined in an 80 ° C. oven for 10 minutes to remove solvent. The thickness of the final film was about 30 μm. The reds array 30 (FIG. 1A) and the test sample 20 (FIG. 1A) were scanned together at 125 [mu] m / sec under a gathered laser beam (average power 650 mW) to expose an area of 0.1 cm ² for 40 seconds (s). . The exposed sample was developed using N, N-dimethylformamide, washed in isopropyl alcohol and air dried. 7 shows a scanning electron micrograph of the structure produced under the test conditions of Example 2. FIG. Reacted polymer post patterns corresponding to the spacing and symmetry of the micro lens array were formed everywhere where the laser beam was scanned across the array.
[231] In Examples 3 to 5, a rectangular array of acrylic diffractive lenses was used to divide the collected beam into a plurality of focused points. The lens pitch was 1.0 mm in both the horizontal and vertical directions with a filling factor of 100%. Each lens was a two-wave design, multilevel diffraction member with a design focal length of 633 mm to 10.0 mm.
[232] Example 3
[233] The apparatus used in Example 3 is shown in FIG. As shown, the exposure system 610 included an array 620 of diffractive lenses on wedges 612 and 614 on the substrate 630. The array 620 includes a diffractive lens 622, which focused the incident light 640 at the focus 614 (ie, 614a-614c). The substrate 630 included a photoreactive composition layer 634 and a microscope slide 632 coated on the slide 632 at the interface 636. The position of the array 630 was adjusted so that the focal point 614 of the diffractive lens 622 nearly matched the substrate / polymer interface 636. The laser beam size was magnified to about 5X using a Galilean telescope setup to fully charge four or more diffractive lenses 622. Both the diffractive lens array 620 and the test sample 630 were scanned together at 125 μm / s under a gathered and expanded laser beam (average power 230 mW). The same test sample as described in Example 2 was prepared and exposed, developed in N, N-dimethylformamide, washed with isopropyl alcohol and air dried.
[234] 9 and 10 show scanning electron micrographs of the structure created under the imaging conditions of Example 3. FIG. The mounds corresponding to the pattern of the polymer posts reacted and the spacing and symmetry of the diffractive lens array are visible. The shape of the individual posts is more irregular than in Example 2, which represents the more complex focusing characteristics of the arrangement 620.
[235] Example 4
[236] In Example 4, the square array of diffractive lenses was fixed relative to the laser beam and the substrate was scanned from below. This optical arrangement allows for the generation of random patterns at multiple imaging points. The size of the laser beam was magnified to about 5X using a Galilean telescope setup to fully fill four or more diffractive lenses and adjust the position of the zone plate to bring the focal point nearly to the substrate / polymer boundary (see FIG. 8). Any test pattern can be recorded using an optical arrangement, while in this embodiment the stage has been programmed to produce a test pattern of two entangled squares. The same test sample as in Example 2 was prepared and exposed by scanning the substrate at the bottom of the array at 125 μm / s (230 mW average laser power). The sample was then developed in N, N-dimethylformamide, washed with isopropyl alcohol and air dried. 11 shows an optical micrograph of the structure produced under the imaging conditions of Example 4. FIG. Test patterns were reproduced at the focus of each of four different imaging points. The polymer had good adhesion to the substrate.
[237] Example 5
[238] In Example 5, imaging with patterned light of a hybrid polymer system has been described. Hybrid polymer systems consisted of reactive monomers in a thermoplastic matrix. The refractive index and density of the photoreactive composition was increased in the illumination region as a result of the polymerization and subsequent diffusion of the monomer into the illumination region. After the desired structure is created, the entire film can be fully exposed using a single photon source to fix the image forever.
[239] The photoreactive compositions of Table 2 were prepared as about 40% solid solutions in 1,2-dichloroethane and spun coated onto microscope slides. The coated slides were baked in an 80 ° C. oven for 10 minutes to remove solvent (final film thickness was about 30 μm). The same optical placement and test pattern as in Example 4 was used. The substrate was scanned under 125 μm / s beam (230 mW average power). After imaging, the test sample was exposed to non-following full images using a bank of 3 Phillips TLD 3W lights for 45 minutes to fix the image.
[240] 12 shows an optical micrograph of a refractive index contrast image. The test pattern was reproduced at the focus of each different imaging point.
[241] Photoreactive Composition of Example 5 ingredientweight% Cellulose acetate butyrate CAB-531-1 from Eastman Chemicals, Kingsport, TN49.99 Phenoxyethyl acrylate SR-339 (Sartomer Co., West Chester, PA)38.75 2- (1-naphthoxy) ethyl acrylate *5.53 SR-351 (Sartomer Co., West Chester, PA)0.92 Bis- [4- (diphenylamino) styryl] -1,4- (dimethoxy) benzene0.96 CGI 7460 (Ciba Specialty Chemicals, Tarrytown, NY)1.92 Diaryliodonium hexafluorophosphate, SR1012 (Sartomer Co., West Chester, PA)1.92
[242] 2- (1-naphthoxy) ethyl acrylate was prepared as described in US Patent Application No. 09 / 746,613, filed December 21, 2000.
[243] Example 6
[244] 13 shows an exposure system 710 used in Example 6. FIG. Pieces of Corning SMF-28 single mode optical fiber were used as a linear array of cylindrical lenses 720 for imaging. The same test substrate 730 as in Example 2 was prepared. The optical fibers were stripped of the outermost sheath using a fiber stripper and wiped off with a solvent and then pressed lightly onto the top surface of the unreacted test sample 730 as shown in FIG. Subsequently, the substrate 730 was raster-scanned at 250 μm / s under the collected laser beam 740 (640 mW average laser power). The Y-stage was moved about half of the beam diameter on each pass. After imaging, test samples were developed in N, N-dimethylformamide, washed with isopropyl alcohol and air dried. 14 and 15 show a scan of the resulting high aspect ratio polymer line.
[245] Example 7
[246] As shown in Figure 16, a chirped grating with interference pattern 820 (e.g., a grating in which the spacing between lines becomes smaller at each successive fringe) is the plane wave 860 and It is formed in photoreactive composition 834 due to the use of an interference fringe pattern generated by the combination of cylindrical wavelengths 850. Straight interference fringes are formed in a single plane by a combination of two plane waves (parallel has an antiparallel propagation direction) which is incident on the image plane. Parallel interference fringes with chirped periods are formed by placing a cylindrical lens 840 in the path of one beam (with a uniform axis of lens 840 parallel to the interference fringe 826 from the original placement). do. Such techniques are well known in the art with respect to the manufacture of fiber break gratings (see, eg, R. Kashyap, Fiber Bragg Gratings, Academic Press, 1999). As can be seen in Figure 16, the fringe period at the left edge 822 of the grating 820 is smaller than without the cylindrical lens (as a result of the increased angle of incidence). The period at the right edge 824 of the grating is not affected. The chirp rate of the interference pattern 820 can be changed by changing the focal length of the cylindrical lens 840 and / or by changing the distance between the lens 840 and the interference plane and / or at the second beam 860. It can be controlled by placing a cylindrical lens (of similar orientation).
[247] Short pulses used in multiphoton absorption exposure systems allow a small portion of the interference pattern to react during each radar pulse. Thus, the overlapping of the pulses to form a selected region of the three-dimensional interference pattern 820 by accurately matching the paths of both the beam 850 and the beam 860. This path length-matching is performed by passing beam 850 and beam 860 through separate optical delay lines (Kirkpatrick et al., Appl. Phys. A, 69,461). Carefully adjusting the path length of each beam to the other allows different portions of the chirped interference pattern 820 to react with successive laser pulses.
[248] Example 8
[249] This embodiment illustrates the use of three-beam interference to form multiple photopolymerized regions by a multiphoton absorption process. It is well known that the interference of two coherent light beams in space and time creates a pattern of fringes of high and low intensity that periodically depend on the angle between the incoming beams. In this embodiment, the interference of the three coherent pulsed laser beams defines a two-dimensional arrangement of bright and dark regions used to create an arrangement of corresponding two-dimensions of the photopolymerized region in a single image plane. Used for.
[250] The recording laser is an amplified titanium: sapphire laser delivering 800 mW at 1 nm with a pulse width of 120 fs at 800 nm. The TEM ₀₀ output from the laser passes through two beam splitters to produce three independent beams of approximately equal intensity. The optical train of the two beams includes glass wedges in the rotating optical mount as well as independent optical delay lines. By rotating the mount, the optical path length can be precisely adjusted. These beams are recombined in the sample shown in FIG. 5 so that the angles between each beam are about 120 degrees. For the purpose of optical alignment only the first two beams (one with delay line and one without) interfere. The length of the optical delay line is adjusted until the pulses from the first two beams in space and time overlap, as indicated by the sharp rise in the two photon fluorescence intensity and observation of the fringe interference pattern. A third beam is then introduced and the length of its optical delay is again adjusted until there is a marked increase in the two photon fluorescence intensity and an interference pattern is observed.
[251] 40 wt% cellulose acetate butyrate (n is about 1.46, Eastman Chemicals, Kingsport, TN), 23 wt% phenoxyethylacrylate (Sartomer Company, West Chester, PA), 34 wt% bisphenol A glycerol diacrylic Rate (Ebecryl 3700, UCB Chemicals, Symra, GA), 2% by weight of diaryliodonium salt (Sartomer Company, West Chester, PA), and 1% by weight of bis- [4- (diphenylamino) styryl] Prepare a solution (40% solids in 1,2-dichloroethane) comprising -1,4- (dimethoxy) benzene. The solution is coated on a silicon wafer about 100 microns thick and dried in an 80 ° C. oven. The test sample is placed and exposed so that three beams interfere in the volume of the sheath, resulting in a two-dimensional hexagonal honeycomb pattern in a single image plane. The refractive index modulation of the reacted region is at least 0.005 compared to the subsequent reaction matrix. The sheath is then fully exposed in a non-image-dependent manner using a bank of 3 Philips TLD 3W-05 bulbs with the main output at 450 nm for 30 minutes. The film has a refractive index modulation of at least 0.005 for the patterned area.
[252] The entire disclosures of patents, patent documents and publications cited herein are incorporated by reference as if individually cited. Various changes and modifications of the present invention will be apparent to those skilled in the art without departing from the original meaning and scope of the present invention. The present invention should not be unreasonably limited by the specific aspects and embodiments described herein and it should be understood that these embodiments and aspects exist as examples within the scope of the invention, which are limited only by the claims which follow. do.

权利要求:
Claims (35)
[1" claim-type="Currently amended] A method of creating at least partially reacted material regions in a photoreactive composition,
Providing a photoreactive composition,
Providing a light source of sufficient light to simultaneously absorb two or more photons by the photoreactive composition,
Providing an exposure system comprising at least one diffractive optical member capable of inducing multiphoton absorption along an image,
Generating a pattern of three-dimensional light that is not random by the exposure system,
Exposing the photoreactive composition to a pattern of three-dimensional light produced by the exposure system to at least partially react with some material corresponding to a non-random three-dimensional incident light pattern.
Method comprising a.
[2" claim-type="Currently amended] The method of claim 1, wherein the exposure comprises pulsed irradiation.
[3" claim-type="Currently amended] The method of claim 2, wherein the pulse irradiation is performed using a near infrared pulse laser having a pulse length of less than about 10 nanoseconds.
[4" claim-type="Currently amended] The method of claim 1, wherein the diffractive optical member is a diffraction mask.
[5" claim-type="Currently amended] The photoreactive composition of claim 1, wherein the photoreactive composition comprises from about 5% to about 99.79% by weight of the at least one reactive species, from about 0.01% to about 10% by weight of the at least one multiphoton photosensitizer, based on the total weight of solids At least about 10% by weight of at least one electron donor compound, and from about 0.1% to about 10% by weight of at least one photoinitiator.
[6" claim-type="Currently amended] The method of claim 1, wherein the diffractive optical member is capable of beamsplitting, wave deformation, or both.
[7" claim-type="Currently amended] A method of creating at least partially reacted material regions in a photoreactive composition,
Providing a photoreactive composition,
Providing a light source of sufficient light to simultaneously absorb two or more photons by the photoreactive composition,
Providing an exposure system comprising an array of one or more refractive micro optical members capable of inducing multiphoton absorption in accordance with an image,
Generating a pattern of three-dimensional light that is not random by the exposure system,
Exposing the photoreactive composition to a pattern of three-dimensional light produced by the exposure system to at least partially react with some material corresponding to a non-random three-dimensional incident light pattern.
Method comprising a.
[8" claim-type="Currently amended] 8. The method of claim 7, wherein the exposure comprises pulsed irradiation.
[9" claim-type="Currently amended] The method of claim 8, wherein the pulse irradiation is performed using a near infrared pulse laser having a pulse length of less than about 10 nanoseconds.
[10" claim-type="Currently amended] 8. The method of claim 7, wherein the refractive micro optical member array comprises an optical fiber array.
[11" claim-type="Currently amended] The photoreactive composition of claim 7, wherein the photoreactive composition comprises from about 5% to about 99.79% by weight of the at least one reactive species, from about 0.01% to about 10% by weight of the at least one multiphoton photoresist, At least about 10% by weight of at least one electron donor compound, and from about 0.1% to about 10% by weight of at least one photoinitiator.
[12" claim-type="Currently amended] A method of creating at least partially reacted material regions in a photoreactive composition,
Providing a photoreactive composition,
Providing a light source of sufficient light to simultaneously absorb two or more photons by the photoreactive composition,
A beam of first light comprising a first wave shape and a beam of second light comprising a second wave shape, the first wave shape inducing multiphoton absorption according to the image, which is substantially different from the second wave shape. Providing an exposure system that can
Generating a pattern of non-random three-dimensional light by the exposure system using optical interference between the beam of first light and the beam of second light,
Exposing the photoreactive composition to a pattern of three-dimensional light produced by the exposure system to at least partially react with some material corresponding to a non-random three-dimensional incident light pattern.
Method comprising a.
[13" claim-type="Currently amended] The method of claim 12, wherein the exposure comprises pulsed irradiation.
[14" claim-type="Currently amended] The method of claim 13, wherein the pulse irradiation is performed using a near infrared pulse laser having a pulse length of less than about 10 nanoseconds.
[15" claim-type="Currently amended] The method of claim 12, wherein the light source comprises a pulsed laser.
[16" claim-type="Currently amended] The photoreactive composition of claim 12, wherein the photoreactive composition comprises from about 5% to about 99.79% by weight of the at least one reactive species, from about 0.01% to about 10% by weight of the at least one multiphoton photoresist, At least about 10% by weight of at least one electron donor compound, and from about 0.1% to about 10% by weight of at least one photoinitiator.
[17" claim-type="Currently amended] A method of creating at least partially reacted material regions in a photoreactive composition,
Providing a photoreactive composition,
Providing a light source of sufficient light to simultaneously absorb two or more photons by the photoreactive composition,
Providing an exposure system capable of causing multiphoton absorption according to an image, wherein the exposure system comprises at least three light beams, each of which comprises at least one shaped beam and at least one of the other light beams. Having a wave shape that is the same as or substantially different from the shape,
Generating a pattern of non-random 3-dimensional light by the exposure system using optical interference derived from three or more light beams,
Exposing the photoreactive composition to a pattern of three-dimensional light produced by the exposure system to at least partially react with some material corresponding to a non-random three-dimensional incident light pattern.
Method comprising a.
[18" claim-type="Currently amended] The method of claim 17, wherein the exposure comprises pulsed irradiation.
[19" claim-type="Currently amended] The method of claim 18, wherein the pulse irradiation is performed using a near infrared pulse laser having a pulse length of less than about 10 nanoseconds.
[20" claim-type="Currently amended] 18. The method of claim 17, wherein the light source comprises a pulsed laser.
[21" claim-type="Currently amended] 18. The method of claim 17, wherein the photoreactive composition comprises from about 5% to about 99.79% by weight of the at least one reactive species, from about 0.01% to about 10% by weight of the at least one multiphoton photoresist, based on the total weight of solids At least about 10% by weight of at least one electron donor compound, and from about 0.1% to about 10% by weight of at least one photoinitiator.
[22" claim-type="Currently amended] An apparatus for reacting a photoreactive composition,
Photoreactive composition,
A light source of sufficient light to simultaneously absorb two or more photons by the photoreactive composition,
An exposure system comprising at least one diffractive optical member, which can cause multiphoton absorption along an image, can produce a pattern of non-random 3-dimensional light, and can be applied to a pattern of non-random 3-dimensional light. An exposure system capable of at least partially reacting with some corresponding material
Apparatus comprising a.
[23" claim-type="Currently amended] The apparatus of claim 22, wherein the light source comprises a pulsed laser.
[24" claim-type="Currently amended] The method of claim 22, wherein the photoreactive composition comprises from about 5% to about 99.79% by weight of the at least one reactive species, from about 0.01% to about 10% by weight of the at least one multiphoton photoresist, based on the total weight of solids At least about 10% by weight of at least one electron donor compound and from about 0.1% to about 10% by weight of at least one photoinitiator.
[25" claim-type="Currently amended] 23. The apparatus of claim 22, wherein the diffractive optical member enables beamsplitting, wave deformation, or both.
[26" claim-type="Currently amended] The apparatus of claim 22, wherein the diffractive optical member is a diffraction mask.
[27" claim-type="Currently amended] An apparatus for reacting a photoreactive composition,
Photoreactive composition,
A light source of sufficient light to simultaneously absorb two or more photons by the photoreactive composition,
An exposure system comprising an array of one or more refractive micro-optical members, capable of causing multiphoton absorption according to an image, creating a pattern of non-random 3-dimension light, and non-random 3-dimension light An exposure system capable of reacting at least partially with some material corresponding to the pattern of
Apparatus comprising a.
[28" claim-type="Currently amended] The apparatus of claim 27 wherein the light source is a pulsed laser.
[29" claim-type="Currently amended] The method of claim 27, wherein the photoreactive composition comprises from about 5% to about 99.79% by weight of the at least one reactive species, from about 0.01% to about 10% by weight of the at least one multiphoton photoresist, based on the total weight of solids At least about 10% by weight of at least one electron donor compound and from about 0.1% to about 10% by weight of at least one photoinitiator.
[30" claim-type="Currently amended] 28. The apparatus of claim 27, wherein the arrangement of refractive microscopic optical members comprises an arrangement of optical fibers.
[31" claim-type="Currently amended] An apparatus for reacting a photoreactive composition,
Photoreactive composition,
A light source of sufficient light to simultaneously absorb two or more photons by the photoreactive composition,
An exposure system comprising a beam of first light comprising a first wave shape and a beam of second light comprising a second wave shape, wherein the first wave shape is substantially different from the second wave shape, and the exposure system comprises: Can induce multiphoton absorption according to the image, generate a pattern of non-random 3-dimension light and at least partially react with some material corresponding to a pattern of non-random 3-dimension light Exposure system
Apparatus comprising a.
[32" claim-type="Currently amended] 32. The apparatus of claim 31 wherein the light source comprises a pulsed laser.
[33" claim-type="Currently amended] 32. The method of claim 31, wherein the photoreactive composition comprises from about 5% to about 99.79% by weight of the at least one reactive species, from about 0.01% to about 10% by weight of the at least one multiphoton photoresist, based on the total weight of solids At least about 10% by weight of at least one electron donor compound and from about 0.1% to about 10% by weight of at least one photoinitiator.
[34" claim-type="Currently amended] An apparatus for reacting a photoreactive composition,
Photoreactive composition,
A light source of sufficient light to simultaneously absorb two or more photons by the photoreactive composition,
An exposure system comprising at least three light beams, wherein each of the at least three light beams includes a shaped wavehead and has a wave shape that is the same as or substantially different from the wave shape of the other light beams; Exposure system that can cause multiphoton absorption, which can generate a pattern of non-random 3-dimensional light and can react at least partially with some material corresponding to a non-random 3-dimensional incident light pattern
Apparatus comprising a.
[35" claim-type="Currently amended] The method of claim 34, wherein the photoreactive composition comprises from about 5% to about 99.79% by weight of the at least one reactive species, from about 0.01% to about 10% by weight of the at least one multiphoton photoresist, based on the total weight of the solid At least about 10% by weight of at least one electron donor compound and from about 0.1% to about 10% by weight of at least one photoinitiator.

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AU6692001A|2001-12-24|

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WO2001096962A2|2001-12-20|

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WO2001096962A3|2002-04-18|

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EP1292863A2|2003-03-19|

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JP2004503832A|2004-02-05|

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KR100795762B1|2008-01-21|

引用文献:

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公开号 | 申请日 | 公开日 | 申请人 | 专利标题

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法律状态:
2000-06-15|Priority to US21167500P

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2000-06-15|Priority to US60/211,675

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2001-06-14|Application filed by 쓰리엠 이노베이티브 프로퍼티즈 캄파니

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2003-09-26|Publication of KR20030076237A

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2008-01-21|Application granted

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2008-01-21|Publication of KR100795762B1

优先权:

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申请号 | 申请日 | 专利标题

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US21167500P| true| 2000-06-15|2000-06-15|

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US60/211,675|2000-06-15|