巴西专利BR112013023586B1 method of forming a nanopore in a nanometer material and nanometer structure

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专利摘要:
METHOD OF FORMING A NANOPORE IN A NANOMETRIC MATERIAL AND NANOMETRIC STRUCTURE. The present invention relates to a method of forming a nanopore in a nanometer material, a nanopore nucleation site is formed at a location that is inside the side edges of the nanometer material by directing a first energy beam selected from the beam group. of ions and beam of neutral atoms, to the interior location for a first period of time that imposes a first dose of the beam, which causes removal of no more than five interior atoms from the interior location to produce, in the interior location, a nucleation site nanopore having a plurality of edge atoms. A nanopore is then formed at the nanopore nucleation site by directing a second energy beam selected from the group consisting of electron beam, ion beam and neutral atom beam, to the nanopore nucleation site with an energy beam that removes the edge atoms at the nanopore nucleation site, but does not remove the volume composition atoms from the nanometric material.
公开号:BR112013023586B1
申请号:R112013023586-1
申请日:2012-03-14
公开日:2021-01-26
发明作者:Christopher J. Russo；Jene A. Golovchenko；Daniel Branton
申请人:President And Fellows Of Harvard College；
IPC主号:

专利说明:

[0001] [0001] This Application claims the benefit of United States Provisional Application No. 61 / 452,704, filed on March 15, 2011, all of which is incorporated by reference. DECLARATION ON RESEARCH Sponsored by the Federal Government
[0002] [0002] The present invention was made with the support of the Government under Contract N ° R01HG003703, granted by the National Institutes of Health. The Government has certain rights over the invention. BACKGROUND
[0003] [0003] The present invention relates to the nanoscale manufacturing technique and, more particularly, it relates to techniques for the production of nanopores in nanometric solid-state materials.
[0004] [0004] Nanometric solid-state materials, that is, solid-state materials that can exist in equilibrium with only nanometers in thickness, include a wide variety of materials, such as monolayer materials, few monolayers and with a single molecule, which are becoming increasingly important for a wide variety of applications including, for example, electronic, biological and chemical applications. Many of these applications require high-precision nanoscale features and structures for operation. For example, well-defined nanopores or nanoscale pores having a diameter of less than about 100 nanometers, are particularly required for many applications because of the nanoscale of the application itself or the environment in which the nanopore has to function.
[0005] [0005] For example, nanoscale devices with articulated nanopores are of great interest in allowing the localization, detection and characterization of molecules, such as individual DNA molecules or protein molecules. Nano-pore filters and nanoscale membranes are equally important for many critical biological characterization and separation procedures, as well as filtration processes. Many other micro-fluidic and nano-fluidic control and processing applications have similarly nanoscale capabilities in nanometric materials.
[0006] [0006] To produce a nanoscale structure, like a nanopore in a nanometrically thin material, it is generally required to manipulate the material with the precision of a single atom. This is in contrast to most conventional microelectronic manufacturing processes which, typically, require only precision that approaches the micronic scale. But without resource resolution and manufacturing precision at the atomic level, in general, it has not been possible to manipulate nanometrically thin materials in a way that exploits the particular characteristics that arise at the nanoscale.
[0007] [0007] High-precision nanoscale processing has historically required a one-on-one manufacturing paradigm that is often expensive and inefficient. In general, high volume batch manufacturing techniques for the production of conventional microelectronics have been incompatible with the production of resources and material handling at the nanoscale. But without the ability to mass-produce precisely, reproducibly and inexpensively at nanoscale resources, such as nano-pores, many nanoscale systems cannot be developed for the commercial implementation of many important nanoscale applications. SUMMARY OF THE INVENTION
[0008] [0008] A method and corresponding structures are provided that overcome the limitations of the preceding processes to form nanopores in a controllable manner. In an exemplary method of forming a nanopore in a nanometer material, a nanopore nucleation site is formed at a location of the nanometer material that is internal to the lateral edges of the material by directing a first energy beam selected from the group of ion and beam bundles of neutral atoms, for the internal location for a first period of time that imposes a first dose of the beam, which causes the removal of no more than five internal atoms from the internal location to produce, at the internal location, a nanopore nucleation site having a plurality of edge atoms. A nanopore is then formed at the nanopore nucleation site by directing a second energy beam selected from the group consisting of electron beam, ion beam and neutral atom beam, to the nanoporous nucleation site with beam energy which removes the edge atoms at the nanopore nucleation site, but does not remove atoms in general from the nanometric material.
[0009] [0009] With this method, a nanometric structure with nanopores can be produced. The structure is formed of a waterproof, self-supporting nanometric material having a thickness of no more than about 5 nm. In the nanometric material, there are a plurality of nanopores of at least about 1,000 nanopores / cm2. Each of the nanopores has a diameter that is no larger than about 10 nm. The plurality of nanopores is monodisperse in diameter, with a variation of about ± 30%.
[0010] [00010] This nanometric structure of the nanopores and the method for producing the nanopores allows a wide range of microfluidic and nanofluidic applications, including molecular detection and analysis, filtration and separation of fluids and fluidic reactions.
[0011] [00011] Other characteristics and advantages will be evident from the following description and attached figures and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [00012] Fig. 1 is a flow chart of a two-step process for the production of a nanopore in a nanometric material; Figures 2A and 2B are schematic views of nanometric materials arranged through an opening on a support structure and arranged through a series of openings on a support structure, respectively, for carrying out the flowchart method of Fig. 1; Figures 3A-3E are schematic side views of a nanometer material as the nanometer material is processed in the flowchart steps of Fig. 1; Fig. 4 is a schematic side view of a standardized shielding material used to selectively mask a nanometric material during the nanopore manufacturing process of the flowchart of Fig. 1; Figures 5A-5B are schematic views of nanopores formed in nanometric materials arranged through an opening on a support structure and arranged through a series of openings on a support structure, respectively, produced using the flowchart method of Fig. 1; Fig. 6A is a graph of the average nanopore radius as a function of the electron dose for five experimental nanopores; Fig. 6B is a graph of the nanopore radius as a function of the electron dose for each of the nanopores from which data were taken for the graph of Fig. 6A; Fig. 7 is an electron micrograph of a graphene region in which a series of nanopores were formed using the flowchart process of Fig. 1; and Fig. 8 is a graph of the nanopore radius distribution for the electron microscopy of Fig. 7. DETAILED DESCRIPTION
[0013] [00013] With reference to Fig. 1, a process 10 for controlled formation of one or more nanopores can, in general, be implemented in a nanometric material with the two steps shown in it. In a first step 12, at least one nanopore nucleation site is produced at a selected location or at several selected locations in a nanometric material for which controlled manufacture of a nanopore is desired. Then, in a second step 14, a nanopore is controlled in a controlled manner at the nucleation site or sites. Each of these steps is described in detail below.
[0014] [00014] This two-stage nanopore formation method can be applied to any suitable material, but it is particularly suitable for the production of nanopores in a solid state material or structure that is characterized by a thickness that is nanometric and, for many applications, which is less than about 5 nanometers thick or less than 3 nanometers thick. Such nanometric materials include, for example, atomically thin materials which, in general, can be described as materials having a thickness of an atomic monolayer or some atomic layers, such as a monolayer, bilayer or a triple layer of atoms. A mono-atomically thick material is defined here as a material which is one atom thick, but need not be atoms of just one element. Atoms from a plurality of different elements can be included in an atomic layer. The mono-atomically thick layer can be decorated in the upper and / or lower layer with heterogeneous atoms and other species that do not reside in the plane of the atoms. Such atomically thin materials include, for example, two-dimensional self-supporting atomic crystals and other structures having a characteristic unit, such as a lattice constant, that is repeated in two dimensions but not in the third. Atomically thin materials also include non-crystalline materials, such as glassy materials for which a monoatomic layer and a few atomic layers can be formed. Other examples of nanometric materials include materials that are single molecule thick or that are two or three molecules thick.
[0015] [00015] Examples of nanometric materials that are well directed using the method include graphene, low-layer graphene, fluorographene, graphane, graphene oxide, hexagonal boron nitride (hexagonal-BN), mono-atomic glasses and other materials. Other suitable materials include, for example, MoS2, WS2, MoSe2, MoTe2, TaSe2, NbSe2, NiTe2, Bi2Sr2CaCu2Ox and Bi2Te3. These are representative examples of suitable solid-state nanometric materials, but they are not limiting; any suitable material in which one or more nanopores are being formed can be employed.
[0016] [00016] In the method, a selected nanometer material is provided in a configuration suitable for processing to produce one or more nanopores in the material. The nanometric material is preferably arranged in such a way that one or more energetic species can be directed through the material for both the production of a nucleation site for the nanopores and the controlled formation of a nanopore at the site, as explained in detail below . For many applications, it may be convenient to provide the nanometric material on an underlying support structure, continuous or discontinuous, in any convenient orientation that accommodates such nanopore processing. The support structure can be discontinuous, with a topology and material configuration depending on the application for which it is intended, and can serve as a patterned masking material, for example, with openings of a selected mask pattern, as described below. The nanometric material in which a nanopore is being formed can, for example, be self-supporting, with support at the side edges near or at the periphery of the material or at locations in interior points or in another configuration that accommodates the direction of an energetic species through nanometric material. The nanometric material can be synthesized in position, for example, in situ, in a device or configuration system, on a selected support structure, or it can be produced or synthesized in whole or in part elsewhere and then transferred to the structure selected support medium.
[0017] [00017] The support structure can be provided as any suitable support material, including materials for microelectronics and substrates that are electrically conductive or electrically insulating. The support structure can be provided as a volume composition structure having the composition of the nanometric material or it can be provided as a heterogeneous combination of materials. In one example, a support structure is provided as a frame and the nanometric material on which one or more nanopores are being produced is transferred to the frame.
[0018] [00018] For example, a silicon substrate can be configured as a support with a frame membrane, for example, a silicon nitride or other frame membrane material having one or more openings in the frame membrane. As shown in FIG. 2A, the nanometer material 16 can be positioned on the frame membrane 18 on the substrate 20. The frame membrane 18 thus functions as a support structure around opening 22 to allow a self-supporting region of nanometric material 24 through opening 22. As shown in FIG. 2B, this configuration can be extended to accommodate any number of distinct areas of nanometric material which are each suspended 24 in a matrix 26, arranged in a support frame 28 through openings in the frame membrane on a substrate.
[0019] [00019] In general, the openings provided in the support frame membrane layer may, for example, be rectangular, circular or of any other suitable geometry and may have, for example, between about 5 - 10 nm and about 200 nm extension or other geometry and extension corresponding to a selected nanopore size and location, as explained in more detail below. For many applications, it may be preferred that the opening in the support frame membrane is at least about ten times greater than the nanopore to be formed in the nanometric material.
[0020] [00020] In another example, a transmission electron microscopy grid (Transmission Electron Microscopy - TEM) can be used as a support structure for a nanometric material to be processed. The TEM grid can be covered with a suitable material, such as a thin film of amorphous carbon, and one or more holes or an array of holes can be formed in the film to provide a frame for the nanometric material. Others of such arrangements can be employed and no particular frame or support is required.
[0021] [00021] When the nanometric material is synthesized separately from a support or framework, the material can be transferred to a support or framework at a convenient time in the synthesis process. In one example, a single layer of graphene or graphene with few layers is synthesized and, once synthesized, it is transferred to a selected support structure. In this example, graphene can be synthesized by means of a suitable process, for example, a chemical vapor deposition process (Chemical Vapor Deposition - CVD) or by ion implantation or gas phase synthesis or another synthesis technique on a structure suitable, for example, a layer of metal or substrate, or it can be produced by exfoliating graphite in a conventional manner. Alternatively, the material can be synthesized by means of a suitable process, for example, (CVD), ion implantation or other synthesis technique, on a suitable structure, for example, a metal layer or substrate, after which the structure , for example, a layer of metal or substrate, can be converted into a support structure for the nanometric material through some method, such as standard chemical attack, which does not affect the nanometric material through which nanopores must subsequently be formed . In particular, the nanometric material synthesis process is necessary and the nanometric material to be processed, such as graphene, can be produced in any suitable manner.
[0022] [00022] In a particularly convenient graphene synthesis process, a sheet of nickel or copper can be annealed at a low pressure at a temperature, for example, about 1,000 ° C for about 10 minutes under the flow of H2 and then also exposed to CH4 flow for about 10 minutes at 1,000 ° C to grow a graphene region or regions. At the end of the 10-minute growth stage, the leaf is cooled to room temperature with a flow of H2 in a process that takes about 2 hours.
[0023] [00023] If the nanometer material to be processed is produced on a synthesis structure, such as the synthesis of graphene on copper foil that we have just described, then it is preferable that the nanometer material is very clean and, if the nanometer material it must be transferred, this transfer must take place very carefully so as not to damage or contaminate the nanometric material. For example, once graphene is synthesized on a copper sheet, a suitable piece of graphene on the sheet can be perforated and placed on a clean acid-washed glass slide for handling during transfer to a support structure. Polymer-based cable materials can alternatively be employed. Where the support structure is, for example, a TEM grid having a carbon layer only, a droplet of deionized water or other suitable liquid is placed first on the grid layer and then, when contacted with graphene, the carbon film is pulled in close contact with the graphene by the recoil interface from the liquid. A glass slide can be placed over the TEM grid to allow force to be applied during contact.
[0024] [00024] The copper film on which graphene was synthesized can then be etched from below, for example, by floating the structure over an appropriate corrosive product, for example, a corrosive copper product including FeCl3 for an appropriate period, for example, 15 minutes for a 25 μm thick sheet. If overwritten, FeCl3 will attack the grid for TEM in places where the grid is exposed at the edges of the carbon layer. Similarly, a polymeric film can be removed after placing the graphene. Once the copper film or other material is removed, the graphene as positioned in the TEM grid can be cleaned, for example, by floating the structure in 1 N HCl, to remove residual iron from FeCl3 exposure for about 10 minutes and then floated in multiple rinses of deionized water, for example, about three rinses of 10 minutes each to remove any residual dry salt in dry nitrogen.
[0025] [00025] For many nanometric materials in which a nanopore is being formed, for example, graphene, a high degree of cleanliness is especially preferred, specifically over graphene, for example, to reduce the density of hydrocarbon contaminants, so that mobile hydrocarbons on the graphene surface are substantially reduced. This high degree of cleanliness may be preferred to assist in the process of forming nanopores. Therefore, if after the cleaning and rinsing process described above it is discovered that a certain amount of contamination of the surface continues, it may be preferable to carry out another cleaning step.
[0026] [00026] In an exemplary cleaning process, contaminants are cooked outside the structure. Here, the TEM grid, for example, a layer of graphene affixed as described above, is transferred to an ultra high vacuum (UHV) stainless steel chamber and at a pressure, for example, of less than about 10-8 Torr, the temperature is raised to about 300 ° C. The structure is then baked for at least two hours, and preferably overnight, at this temperature. The chamber is then cooled to room temperature slowly, for example, to less than about 2 ° C / min, with a final pressure in the chamber between, for example, about 10-8 and about 10-9 T It is preferred that the structure be stored at room temperature under UHV conditions until use. This process has been found to produce a graphene surface that is about 40% - 80% free of any contaminating material, as seen through TEM visualization.
[0027] [00027] This example demonstrates that, in general, it is preferred to keep the nanometric material to be processed under conditions of optimal cleaning, so that atomic scale processing of the material is not affected by the contaminants. No particular cleaning or storage processes are required and those processes best suited for a selected material are preferred. With a material selected in place on a support structure, the method for controlled production of a nanopore can be carried out.
[0028] [00028] With reference to Fig. 3A, there is shown a nanometric material 30 to be processed for the production of nanopores, arranged in such a way that a plane of 32 atoms of the material is accessible. In this exemplary illustration, a layer of atoms is shown for clarity in explaining the process steps, but this is not necessary; as explained above, the nanometric material can be a multilayered atomic material, a molecular monolayer material or other nanometric material having a thickness that is generally less than about 5 nm.
[0029] [00029] With the nanometric material in such a configuration, in the first step of the method, one or more nanopore nucleation sites are formed in the nanometric material at locations that are internal to the lateral edges of the nanometric material and in which nanopores must be formed. At such an interior nanopore nucleation site, some disturbance in the continuity of the nanometric material is anticipated, which produces ends of material from which the edge atoms can be removed for controlled formation of a nanopore of a selected size. In other words, due to a rupture in the nanometric material, inner atoms are processed as edge atoms for removal in the process of forming a nanopore. Each nanopore nucleation site is, therefore, a site in an interior location of the nanometric material where edge atoms are produced by the formation of the nucleation site.
[0030] [00030] To form a nanopore nucleation site, some alteration of the atoms of the nanometric material is necessary. In an example of the same, a structural defect or a single set of defects is formed in the nanometric material at a location inside the material's lateral edges. The defect can be created, for example, by replacing a single atom or a small number of atoms in the material or otherwise changing the atomic structure of the material. The term "defect" here, therefore, is intended to refer to an anomaly in the atomic bonding structure of the nanometric material. For example, given the nanometric material graphene, a defect can be created by removing one or two atoms from the carbon structure of the attached sp2 graphene of the material. A sufficient defect exists in the material when the number of bonds that hold one or more atoms in place is changed and / or reduced and the defect is relatively stable at a selected operating temperature. A defect of one or two atoms in a hexagonal structure such as that of graphene can produce three - four border atoms at the location of the defect, and therefore allows the required condition of the production of border atoms at an interior location in the nanometric material to a nanopore nucleation site.
[0031] [00031] In general, changes in the nanometric material at the nucleation site can be produced in any suitable way. In a preferred example, an energetic beam of a selected particle species is directed to a location or locations on the surface of the nanometric material that is selected for the production of a nanopore. An ion beam, for example, an argon ion beam, a beam of α-particles, a beam of high-energy beta particles, a beam of electrons / protons, a beam of reactive ions created by a plasma, such as an oxygen ion or free radicals or other suitable particle beam can be employed. For many applications, an ion beam or neutral atom beam may be preferred for ease of use in conventional microfabrication batch processing sequences. Examples of suitable energy beams include, for example, hydrogen ion beams / proton beams, neon beams and gallium ion beams, among other suitable species. It is not necessary for the energy beam to collide directly on one or more atoms of the nanometric material; the energy provided by the beam can cause a rupture in the atomic bond that displaces one or more atoms.
[0032] [00032] Therefore, the energy of the particle beam is characterized as being above the energy which provides the minimum particle retreat energy necessary to remove at least one atom from the inside of a nanometric structure, called the displacement energy, Edcomposition of volume. In other words, a minimum threshold kinetic energy must be provided by the particle beam so that the incident particle displaces one or more interior atoms, so that a nanopore nucleation site is produced or, otherwise, can disrupt directly and irreversibly. the bonds of the substituting structure.
[0033] [00033] Tm, the maximum energy transmitted in a single backward dispersion event, occurs with a direct head when colliding by an incident particle from the beam; in a relativistic formulation, this transmitted energy is provided as:
[0034] [00034] A simple calculation for the displacement energy, v ° lumen composition, of a particular atom within the volumetric structure of a given material is obtained by adding the energy of all bonds in the structure based, for example, on values tabulated. For example, the estimated energy displacement for a carbon atom in a graphene monolayer using this method is Edcomposition of volume ≈ 6.4 eV × 3 = 19 eV, a value that is reasonably close to the measured values for graphene in graphite in bulk from 20-21 eV. Note that the displacement energy is a function of the angle between the incident beam and the plane of the atoms in the structure. In this analysis, it can be assumed that the beam is substantially perpendicular to the plane of the nanometric material. The minimum beam energy, E, to create a defect can then be calculated using the expression (1) above, with the Tm defined as the displacement energy, Edcomposition of volume, plus some margin of error to compute the uncertainty of the beam energy in the device and the approximate nature of the calculation, say 50%.
[0035] [00035] To obtain a low-energy ion beam having a kinetic energy that is much less than the rest of the energy used to produce nanopore nucleation sites, in which case a non-relativistic analysis applies, Expression (1 ) simplifies for:
[0036] [00036] Based on this expression, it can be specified that, for a low energy ion beam, an appropriate energy beam to remove atoms for production, in a nanometric material, of nanopore nucleation sites, Enuc, including a margin error rate of 50%, is provided as:
[0037] [00037] Based on this Expression (3) above and given the Edcomposition estimates of volume using the method above, the beam energies necessary for a beam of interest can be determined. For example, given an argon ion beam, Table 1 below specifies the beam energy required to form a nanopore nucleation site for three nanometric materials.
[0038] [00038] In most metallic or semi-metallic materials which are not the target of other forms of damage induced by irradiation, below the required beam energy, beam particles fall that do not damage a pure structure, even after very large doses of irradiation. For example, a pristine graphene structure can withstand a dose of> 109 electrons / nm2 at 80 keV, without any damage to the structure.
[0039] [00039] For many applications, the minimum incident beam energy required to produce nanopore nucleation sites can be determined empirically. For example, a selected nanometer material can be irradiated with an energy beam at an initial energy for which Tm ~ 5 eV. Then, the beam energy can be increased slowly, until there is evidence that atoms of the nanometer material are being removed by the beam. This experiment can be conducted in general on a sample of nanometric material if a detector is available to detect in situ receding atoms in the material. Alternatively, this experiment can be performed with several samples of different nanometric material, with gradual increases in energy and a post-imaging stage to determine if the atoms have been removed. Once the appropriate energy is determined for a given incident particle / material combination, then the dose required to remove a particular number of atoms per unit area can also be measured and then specified a priori to create a desired number of nucleation sites per unit area over a selected nanometric material.
[0040] [00040] Once the beam energy is selected, the exposure time of the nanometric material to the energy beam is selected to produce the desired nanopore nucleation site. Specifically, the period of time during which the energy beam is directed to the location or locations in the nanometric material is defined to impose a dose of particles from the beam that produces a nanopore nucleation site. Preferably, the nanopore nucleation site is controlled to be of atomic scale dimensions. The nucleation site, for most applications, can therefore be specified as a location on the nanometer material that is inside the side edges of the nanometer material and in which about five or less interior atoms have been removed by the energy beam. The particle dose of the energy beam, in this way, produces a nucleation site within the nanometric material in which five or less interior atoms have been removed, producing a plurality of edge atoms at the site. For example, given the nanometric material graphene, an argon ion beam dose of about 1 x 1013 Ar + / cm2 in an energy beam of about 3 keV can be employed to produce nanopore nucleation sites in graphene. With this control of the production of the nanopore nucleation site, the continuity of the nanometric material is interrupted by removing five or less atoms in an interior location, so that interior atoms in the site are processed as edge atoms for the formation of a nanopore .
[0041] [00041] Under some processing conditions and for some materials such as graphene, it is demonstrated a resistance by the nanometric material to form a nanopore nucleation site at room temperature, even above the threshold, due to the mobility of the atoms of the nanometric material. As a result, it may be preferred to determine experimentally the characteristic tendency of a selected nanometric material to be changed at a selected operating temperature and to cool the material during irradiation, if necessary, to preserve the change in the material. For example, graphene cooled to 149 ° K and irradiated by 3 keV of Ar + is damaged with defects suitable for nanopore production, but graphene that is irradiated by 3 keV of Ar + ions at 300 ° K shows much less nucleation sites. nanopore. Specifically, at 300 ° K, the probability that a single argon ion will produce a defect for the nucleation of a nanopore is <1 / 10th of the probability at 148 ° K.
[0042] [00042] Therefore, it is desirable to cool the nanometric material to a temperature that reduces atom diffusion on the surface, so that mobile atoms cannot replace atoms removed by the incident energy beam. Based on radiation measurements from graphite, this temperature is understood to be in the range of about 160 ° K - 200 ° K for graphene. As a result, a processing temperature below about 200 ° K may be preferred and at a temperature below about 160 ° K may be more preferred, with lower temperatures improving the efficiency of creating a nanopore nucleation site. It should be understood that this temperature can vary for different nanometric materials. The appropriate processing temperature for a given nanometer material can be determined empirically by reducing the temperature of the nanometer material during energetic beam irradiation until the efficiency of creating the nanopore nucleation site becomes comparable to the cross section for atomic displacement.
[0043] [00043] The production of a nanopore nucleation site in a nanometric material by an input particle is shown schematically in Fig. 3B. A particle 34 in a particle beam 36 is directed towards the nanometric material. The collision of each of such particles 34 with atoms 32 of the material can remove one or a series of atoms in a single collision, with the removed atoms 40 removed from the structure of the nanometric material as the particle passes through and exits 38 of the nanometric material . As shown in Fig. 3C, this results in an altered nanometric material 42, now including a nanopore nucleation site 44 having an edge on which the edge atoms can be removed.
[0044] [00044] The dose of nanopore nucleation generation particles can be controlled so that only an isolated material change or cluster of changes is created at a nanopore site of a nanometric material or at each of a plurality of sites of interest. This can be achieved, for example, using a source calibrated for a precisely controlled beam irradiation duration or, for a liquid environment, for example, feedback control of ionic currents that can be provided, for example, by monitoring the ionic flux through a material, such as a graphene sheet, which is suspended in order to separate two solutions containing ions, one of which is compensated in relation to the other.
[0045] [00045] With this control, the nanometric material to be processed can be positioned in relation to the nanopore nucleation site generation particles so that a change in the material or a cluster of changes is produced at a location that is specified for formation of a nanopore or so that a series of changes in the material are produced through the material to form a matrix of nanopores in the material. Where more than one nanopore is desired, a physical mask configuration can be used to expose only those locations of the nanometric material in which nanopores have to be formed to alter the environment. Here, for example, as shown in FIG. 4, a standardized protective mask 60 of sufficient thickness and suitable material to prevent particle penetration can be positioned in front of the nanometric material 30, so that a source of particles, either focused or blurred, as shown, radiates only one region or selected regions of the nanometric material.
[0046] [00046] Many materials have the power to intercept an ion beam that is sufficient for operation as a relatively thin ion beam mask. For example, a thin sheet of Al, Au, Si, Cu, SiO2, SiNx, nylon, Teflon or other suitable material can be used. In an additional example, alpha particles resulting from radioactive decline have been found to have a very low penetration depth of a few centimeters of air and therefore can be intercepted by a layer of a few micrometers of aluminum foil. Such a sheet layer can be prepared with holes located in a pattern that corresponds to the position or positions of the desired finished nanopores. The sheet can then be used as a protective layer between the nanometer material being processed by defect generation particles and the source of the incoming defect generation particles.
[0047] [00047] In an alternative embodiment, a highly focused beam of particles, for example, a beam of focused gallium ions or another concentrated beam, such as an electron beam, at an appropriate energy, as described above, can be specifically directed for locations where a nanopore nucleation site has to be produced in the formation of a nanopore, in a sequential manner. This sequential site irradiation technique eliminates the need for a physical mask, while at the same time producing defects with nanometric precision in position.
[0048] [00048] The source of the particles to be used to form a nanopore nucleation site does not need to be dried and, rather, can be supplied in an aqueous solution or other suitable environment. For example, an aqueous solution can be provided as a 7% (weight / weight) solution of uranyl acetate in distilled water. Due to the fact that a small percentage of any uranium solution is Ur238, the solution emits alpha particles for collision on a material placed in the solution.
[0049] [00049] As a reference now to Fig. 3D, in the second stage of the process, a nanopore is controlled in a controlled manner at the nanopore nucleation site. At this stage of nanopore formation, the nucleation site 44 is altered in a manner that produces a nanopore in a controlled manner without damaging the nanometric material surrounding the nucleation site. This nanometric material around the nucleation site is defined here as that nanometric material that has not been altered by the nucleation site generation process of the first step in the method.
[0050] [00050] In an exemplary process, as shown in Fig. 3D, a beam 45 of particles 47 that has an energy that is below the energy threshold for drag damage in the intact nanometric material, that is, below the threshold for removing atoms of volume composition of the nanometric material, is normally directed to a plane of 32 atoms of the nanometric material. These energetic particles 47 remove only those atoms of edge 50 in the circumference or perimeter of the nanopore nucleation site 44, while maintaining the integrity of the remaining nanometric material by not removing volume composition atoms from the interior locations of the nanometric material that are not at the nanopore nucleation site.
[0051] [00051] As shown in Fig. 3D, an input particle 52 that reaches the edge of the nucleation site 44 can remove an edge atom 50 at the periphery of the site, while an input particle 54 that reaches the nanometric material in a The distant location of the nanopore nucleation site does not cause removal of a volume composition atom from the inside of the nanometric material. As the irradiation of the nanometric material is continued, additional edge atoms are removed at the periphery of the nucleation site whereas, far from the nucleation site, the nanometric material remains intact and atoms of volume composition are not removed. In the absence of any source of atoms to fill those edge atoms that are removed, a nanopore develops at the nanopore nucleation site. The geometry of the nanopore, therefore, is directly influenced by the evolutionary state of edge atom removal at the nanopore nucleation site. The nanopore can generally be circular, but can have any geometry selected and can include roughness or other non-continuous geometric features.
[0052] [00052] The nanopore diameter increases in direct proportion to the removal environment dose, for example, electrons or ions per unit area, thus giving very precise control of the nanopore area. Since the nanopore can have an irregular geometry, for example, which is not circular, the term diameter can refer, for example, to the largest extent through the nanopore. Beam irradiation of the forming nanopore can be controlled stop when the nanopore reaches the desired size. As shown in Fig. 3E, formation of a nanopore 55 is then completed in the nanometric material 30. The nanopore can be characterized by a larger diameter or extension between the edges that varies, for example, between about 3 Å and about 1,000 Å.
[0053] [00053] Fig. 5A schematically shows an example of the resulting nanopore 70 produced in a nanometric material 16 that is self-supporting and extending through an opening in a structure 18 on a substrate 20. Fig. 5B, of the same Thus, it schematically presents an example of a nanopore matrix 75 produced simultaneously in a self-supporting nanometric material 24 on a frame 28 and substrate 29, with distinct regions selected from nanometric material 76 in which nanopores are provided in a controllable manner.
[0054] [00054] An ion beam, electron beam or other suitable energy beam that can be directed to the plane of a nanometric material can be used in this step of nanopore formation. For many applications, a low-energy ion beam that is blurred over the nanopore scale may be preferred, given the production of nanopore nucleation sites also by an ion beam. An ion beam process in general allows for large-scale production in a practical and efficient way, with the entire process conducted in a low-cost device in which large areas of the device and / or many other devices can be processed in parallel.
[0055] [00055] Due to the fact that the beam is used in the nanopore formation step to selectively remove only atoms at the edge of the nanopore nucleation site, the incident beam energy is adjusted specifically for this condition. Beam particles are therefore preferably characterized by an energy that is greater than that required to remove an atom at the nanopore edge, but less than that which would remove a volume composition atom from the interior of the material. To quantify this condition, an edge atom displacement energy, Edborda, can be defined as the energy needed to remove an atom from the edge of a nanometric material. An incident particle beam must have an energy such that the maximum transmitted energy, Tm, in a single dispersion event, as expressed in Expression (1) above, is defined as: Edborda <Tm <Volume composition (4)
[0056] [00056] The Edborda value, if unknown, can be estimated by adding the binding energies for an atom at one edge of the nanometric material structure using, for example, tabulated values. Considering, for example, a graphene edge atom which has, on average, two bonds to the volume composition structure, then Edborda ≈ 6.4 eV χ 2 = 13 eV, a value that is reasonably close to the experimental value measured from 14.1 eV. Based on this value, if an energy beam with an energy such that Tm - (Edcomposition of volume + Edborda) / 2 = (19 + 13) / 2 = 16 eV is used, then only the atoms at the edge of a site of nucleation of nanopore in graphene will be removed. This value can be further adjusted empirically to optimize the removal of atoms at the edge of a nanopore nucleation site without creating additional defects in the volume composition structure.
[0057] [00057] Once an appropriate energy has been selected for the beam, then the rate of edge atom removal can be measured, either during irradiation if a detector is available in situ to detect particles transmitted through the membrane or on several samples with gradual dose increase, followed by imaging to determine the number of atoms removed per incident particle dose. The irradiation of a nanopore nucleation site by the energy beam is continued until a dose of sufficient beam particles has removed a sufficient number of edge atoms at the nanopore nucleation site to form a selected size nanopore. For example, given the use of an 80 keV electron beam to form nanopores at graphene nanopore nucleation sites, then an electron beam that flows at about 3 x 103 e- / Å2 / s can form a nanopore having a radius of 20 Å in about two hours. Thus, the dose of the energy beam can be selected a priori to produce a corresponding nanopore size.
[0058] [00058] As an alternative to dry beam processing, if it is desirable to keep a nanometer material in a liquid solution, a selected solution can be used to react preferentially with nanopore nucleation sites over the nanometer material. For example, given a graphene material, then nitric acid or other chemicals in solution that are known to react preferentially with altered nanometric sites, such as carbon ring network structures that do not have six elements or the edges of a structure graphene, can be used to form a nanopore at a nanopore nucleation site in graphene. Continuous chemical exposure, for example, to nitric acid, can perform controlled removal of atoms only from the altered site and the edge of the subsequently formed nanopore, while leaving the rest of the graphene intact intact. Such chemical treatment may be preferred to control feedback on the nanopore size by monitoring the ionic flux through the growing nanopore on the graphene sheet. Once a nanopore of selected size has been produced, the reaction can be terminated, for example, by introducing a basic kind of neutralization, such as KOH, to the solution or supplying another basic solution. Alternatively, an automatically operative series of solutions can be employed, for example, with an acid on one side of the nanometer material to engrave a nanopore on the material and a basic solution on the other side of the nanometer material to neutralize the acid and interrupt the process nanopore formation. The ratio of acid molarity to basic molarity can be specified here to determine the nanopore size at which recording is stopped.
[0059] [00059] It has been found that, similar to the formation of a nano-pore nucleation site, nano-pore formation itself can be influenced by temperature. For example, during radiation at room temperature, atoms can diffuse around the inner edge of the nanopore, affecting the overall shape of the nanopore. Controlling the temperature of the nanometric material during irradiation may therefore be preferred to allow an ability to increase or decrease the amount of material diffusion that occurs at the edge of the evolving nanopore and thereby control the shape of the nanopore. For many applications, a nanopore formation temperature of between about 78 ° K and less than about 300 ° K or less than about 200 ° K, may be preferable.
[0060] [00060] The shape of an evolving nanopore can also be controlled by means of a focused electron beam, such as that in a transmission scanning electron microscope (Scanning Transmission Electron Microscope - STEM) and slowly moving the focused beam area to record only particular portions of the nanopore edge. The shape of the nanopore can also be modified by exposing the nanometric material to an increased temperature after irradiation to adjust the shape, for example, rounded, or another aspect of the nanopore.
[0061] [00061] For many applications, it may be preferable to characterize the nanopore formation process empirically so that a nanopore diameter specified a priori can be produced with a corresponding beam dose. In a method to determine this, the nanopore size is experimentally determined, which results as a function of the total dose, for example, total electron dose. For example, for graphene nanometric material, the graphene edge is characterized by a distinct defocused fringe pattern in a transmission electron micrograph (Transmission Electron Micrograph - TEM). The radius of a nanopore in a region of graphene can be determined by selecting the center of the nanopore and integrating the image intensity over azimuth angles as a function of the radius, dividing by the circumference in that radius as a normalization. The deflection point of the defocused edge fringe can be identified as the average radius of the nanopores.
[0062] [00062] For many applications, it may be convenient to image the nanopore during its formation to obtain the necessary radius data. For example, given the formation of nanopores in graphene, exposure by TEM to an electron beam defocused at an energy of about 80 keV, allows the formation of a nanopore in a nanopore nucleation site and provides imaging capabilities for imaging in real-time evolution of the nanopore. Similarly, the process of nanopore formation based on nitric acid described above allows the control of feedback provided by monitoring the flow of ionic current through an evolving nanopore.
[0063] [00063] However, after nanopore radius data is collected, once they are available, the correlation between dose and nanopore radius for a given nanometer material and irradiation and temperature conditions can be determined, so that a an essentially automated approach to the formation of a nanopore of predefined diameter may be allowed. The circumference of a nanopore can be specified as increasing linearly with the dose as the atoms on the edge of the nanopore are removed. For a circular nanopore, this can be specified for the nanopore radius, r, as r = Md, where d is the dose, for example, in electrons / unit area and where M is the constant measure of proportionality.
[0064] [00064] With this specification for obtaining a selected radius, the ability to form large populations of monodispersed nanopores in a selected nanometric material is made possible. Such nanopore populations can be particularly important, for example, for microfluidic applications, such as filtration, molecular analysis and chemical reactions. In general, to allow such applications, the nanometric material is impermeable to a species that is intended to pass through the nanopores. Nanopores can be formed in a matrix that is ordered or with a random configuration and that is monodisperse in diameter. The term monodisperse here is intended to mean a monodisperse diameter of a plurality of nanopores in a population of nanopores, with a variation of about ± 30%. This monodispersity can be obtained in a nanometric material with the two-step nanopore formation method to produce, for example, a plurality of nanopores, each having a diameter, for example, no greater than about 10 nm, for example, not greater than about 4 nm, in a population, for example, of about 1,000 nanopores / cm2 having a monodisperse diameter with a variation of about ± 30%. In a further example, this monodispersity can be obtained in a nanometric material for a selected number of nanopores, for example, at least about 50 nanopores, each having a diameter, for example, no greater than about 10 nm, for example. example, no larger than about 4 nm, having a monodisperse diameter of the nanopore with a variation of about ± 30%.
[0065] [00065] This control of nanopore formation can be easily exploited to form, repeatedly and reliably, populations of nanopores that meet specific requirements for a variety of applications. Whether a nanopore, a small plurality of nanopores or a large population of nanopores is needed, the two-stage nanopore formation process allows for atomic scale control of the nanopore formation process. Example 1 Formation of a 20 Å nanopore in graphene
[0066] [00066] The nanometric material graphene was synthesized by depositing chemical vapor on a 25 μm thick polycrystalline copper substrate (Aesar). The substrate was treated at low pressure under a continuous flow of H2 at 1,000 ° C for ~ 10 minutes, exposed to an additional flow of CH4 for ~ 10 min at 1,000 ° C for graphene growth and then allowed to cool to room temperature under continuous gas flow, which requires about 2 hours. After growth, the graphene was transferred to gold TEM grids covered with a thin film of amorphous carbon with regular matrices of holes on the micronic scale (Quantifoil, Au 1.2 / 2.0). A drop of deionized water was placed on the TEM grid, and then the grid was placed on the graphene, which was pulled into contact with the graphene by the interface away from the water droplet. The copper was then etched underneath, the structure floating on top of the copper etching agent, FeCl3 (Transene). Once recorded, the sample was then floated in 1N HCl to remove residual iron from FeCl3 and then floated in three washes of deionized water to remove any residual salt and dried in dry nitrogen.
[0067] [00067] At this point, several of the structures still contained varying amounts of surface contamination that probably formed during the growth procedure, so that annealing of the contamination was conducted. TEM grids were transferred to a stainless steel UHV chamber that was cooked at 400 ° C only, evacuated to <10-8 torr and then cooked overnight at 300 ° C. The final pressure in the chamber after cooking was ~ 5 x 10-9 torr. The structures were then stored in this chamber under UHV at room temperature until use.
[0068] [00068] To produce isolated nanopore nucleation sites in the graphene structure, the structures were transferred to an ion spray system capable of irradiating the samples at different temperatures with a known dose of ions under UHV conditions. The beam creep was calibrated by measuring the beam counting rate limited by an aperture of known size. Each structure was introduced through a load blocking mechanism and then cooled to a base temperature of 148 ° K. Residual pressure in the chamber was <10-9 torr and residual partial pressures of species up to 100 AMU were monitored with an in situ residual gas analyzer (Ametek) to ensure that there were no hydrocarbons, water or other reactive species detectable in the chamber during irradiation.
[0069] [00069] To produce nanopore nucleation sites in graphene, the positive argon ion beam received a pulse with a duty cycle of 500 msec in 500 msec until the structure reached the desired dose, which was calculated to produce the necessary breakdown of graphene, here 1 x 1013 Ar + / cm2 at 3 keV. The sample was cooled to 149 ° K to reduce the likelihood of atom diffusion on the graphene surface, thereby preventing the movement of the atom from the immediately newly formed nanopore nucleation sites in the structure. Theoretically, each ion passing through graphene has the ability to remove one or two atoms from the network and it is estimated that the spraying yield for a 3 keV argon ion in graphene is in the order of 0.5 carbon atoms removed by of incident argon ions. After exposure to the ion beam to form nanopore nucleation sites was complete, the structure was then heated back to 300 ° K and transferred to a small UHV chamber for storage.
[0070] [00070] The structure was then transferred to a transmission electron microscope (Transmission Electron Microscope - TEM) in a controllable way to produce a nanopore. With TEM, a single crystalline graphene grain was identified using diffraction in the selected area and the grain was verified as a single layer from relative diffraction peak intensities at a slope of 0 °. A selected region in the grain in which an ion beam-induced nanopore nucleation site existed was then continuously irradiated by a parallel electron beam of 80 keV and images of the process were acquired at intervals of 30 or 60 seconds. The structure of the nanometric material was nominally maintained at room temperature inside the electron microscope. The irradiation was periodically interrupted as the diameter of the nanopore grew to verify the control of the process. At an electron beam creep of 3 x 103 e- / Å2 / s, it was discovered that a nanopore with a radius of 20 Ã… was formed in about two hours.
[0071] [00071] Before and after electron beam irradiation, the current of the electron beam was measured with a Faraday cup integral to the support structure (single-tilt Gatan support) attached to a peak-ammeter (Keithley 2400) and the Faraday's beam area was measured directly from an image of the irradiation area of the graphene grain, which was limited by the opening of the condenser. The biggest contribution to systematic error is probably the measurement of the beam current due to re-diffusion and loss of secondary electrons from the 0.49 stereoradians of the exit angle subtended by the entrance to the Faraday beaker.
[0072] [00072] It has been estimated that all other systematic deviations contribute <1% error when crossing section measurements. The residual pressure was less than 1.3 ± 10-7 torr and a liquid nitrogen anti-contamination device in close proximity to the structure protects it from contamination and residual water vapor in the column during electron irradiation. Objective lens anomalies were corrected for 3rd magnitude using a post-objective hexapole corrector (CEOS), aligned to have C1 ≅ + 300 Å, C3 ≅-1 μm and all other anomaly coefficients minimized. The images were filtered at zero loss to ~ 1 eV around the primary energy of 80 keV using the column omega filter to improve the phase resolution in high resolution by removing inelastic electrons. Micrographs were collected on a Gatan Ultrascan 4k camera or a TIVPS 4k camera at a nominal instrument magnification of 400-800 kX or 450 mm camera length for diffraction of the selected area. Example 2 Characterization of nanopore radius correlation for graphene dose
[0073] [00073] To quantify the correlation between the nanopore radius in graphene as a function of the electron dose employed to produce this nanopore ray, the two-step nanopore formation process of Example 1 was performed, here with a beam dose ions of 1 x 1013 Ar + / cm2 for the production of nanopore nucleation sites in graphene and with an electron fluency of 3190 ± 50 e- / Å2 / s for the production of a nanopore at the sites. Sequential micrograph images containing several growing pores were obtained and analyzed by integrating intensity in the micrograph over azimuth angles as a function of the radius, divided by the circumference in this radius. The defocusing point of defocusing at the edge fringe was identified as the average radius of the nanopore.
[0074] [00074] The micrographs were derived corrected using a cross-correlation algorithm and post-processed in ImageJ, with a low pass filter for a 1.0 Â cutoff point, adjusted to 8 bits of linear contrast over the average intensity value and cut to the region of interest. The total exposure time for a specific micrograph was then determined by subtracting the moment value from the image from the moment the exposure started. The exposure time, multiplied by the beam fluency, was then taken as the dose for a particular micrograph, as the beam current varied by <2% during the course of the experiment.
[0075] [00075] Fig. 6A is a graphical representation of the resulting data for the nanopore ray as a function of the electron dose, where each data point is derived from the azimuth integral of a nanopore image in a sequence of acquired images. Analysis on four additional nanopores produced under the same conditions resulted in the measurement of random errors in the radius decline versus the dose and is identified by the gray region. The black line is a better linear fit to the trajectories for the total of five nanopores analyzed. Fig. 6B is a graphical representation of each of the five nanopore radius data sets, provided here separately.
[0076] [00076] Based on these experimental data, it was found that the nanopore circumference increased linearly with the dose as the nanopore edge atoms were removed. The total average cross section, σe, to eliminate the atoms from the nanopore edge was determined from experimental data, based on the slope and density of the carbon atoms at the edge of the nanopores. The result is 8.9 ± 0.4 χ 10-24 cm2, where the error is the standard deviation of five measurements. Using conservative estimates of systematic error in the measurement technique, the maximum and minimum limits on this value are 9.4 and 7.5 χ 10-24 cm2, respectively. Example 3 Formation of high density nanopore in graphene
[0077] [00077] Following the process of Example 1, a 6.27 χ 105 Å2 graphene region was first exposed to a 3 keV argon ion beam to impose a dose of 1 χ 1013 Ar + / cm2 on the formation of nanopore nucleation and then exposed to an electron beam to impose a dose of 9.7 χ 106 e- / Å2 to form nanopores at the nucleation sites. Fig. 7 is a micrograph of the resulting structure, identifying 32 nanopores, as indicated by arrows. The locations of some of the larger and smaller nanopores in the image were determined by looking at the anterior and posterior images in a series of images. The resulting nanopore density corresponds to 5.1 χ 1011 nanopores / cm2. This correlates with the ion beam dose of 1 χ 1013 Ar + / cm2 as each Ar + of 3 keV having a probability of nucleation of a nanopore of about 5% under these irradiation conditions.
[0078] [00078] Fig. 8 is a graph of the nanopore radius distribution for the nanopores shown in the image in Fig. 7. The nanopore radius distribution has been found to have a drastic peak. These data demonstrate that the nanopore formation process is particularly effective in the production of monodispersed nanopores. Monodisperse is defined here as a radius distribution of ± 30%. Example 4 Comparative example of electron beam irradiation without producing a nanopore nucleation site
[0079] [00079] An experiment was conducted to confirm that the synthesis of the nanopore nucleation site is necessary to allow the formation of the nanopore according to the method described above. In the control experiment, a 6.27 χ 105 Å2 graphene region was prepared in the same way as in Example 1, corresponding to the graphene region measured in Example 3. The synthesized graphene was exposed to an electron beam of 80 keV for impose an electron dose of 9.7 χ 106 e- / Å2 as in Example 3. This electron beam energy meets the requirement of the two-stage nanopore formation method because 80 keV is less than necessary to remove volume composition atoms of graphene in the inner region of the graphene material. No ion beam irradiation steps to first form nanopore nucleation sites have been performed. After the electron beam dose was produced, graphene was examined and it was found that it did not include nanopores. This confirms that, without the formation of nanopore nucleation sites, the electron beam dose does not form nanopores.
[0080] [00080] The description and examples demonstrate that the nanopore formation and nucleation process is an elegantly simple, efficient and reproducible process that can be implemented on a large scale over large areas and many devices. Many applications that require mass production of nanopores can therefore be implemented in a practical way and at a reasonable cost.
[0081] [00081] It is recognized, of course, that those skilled in the art may make various modifications and additions to the processes of the present invention without departing from the spirit and scope of the present contribution to the technique. Consequently, it should be understood that the protection intended to be provided by it should be considered as extending to the subject matter of the claims and their equivalents reasonably within the scope of the invention.

权利要求:
Claims (23)
[0001]
Method of forming a nanopore in a nanometric material, the method characterized by the fact that it comprises: form a nanopore nucleation site in a nanometer material, the nanometer material having a thickness less than 5 nm at a location of the nanometer material that is inside the lateral edges of the material when directing a first energy beam, selected from the group of the group consisting of in ion beam and neutral atom beam, inside the location with a beam energy that is at least the energy of the energy beam that provides the nanometric material with an atom with a large amount of Edmassa displacement energy, which can removing atoms of mass from the nanometric material, during a first period of time that imposes a first dose of the beam which causes removal of less than five interior atoms of mass from the interior location to produce, at the interior location, a nucleation site nanopore having a plurality of edge atoms; and form a nanopore at the nanopore nucleation site by directing a second energy beam selected from the group consisting of an electron beam, ion beam, and neutral atom beam at the nanopore nucleation site with a beam of energy that is less than the energy of the energy beam that provides the nanometer material with an atom of large amount of Edmassa displacement energy, removing the edge atoms at the nanopore nucleation site, and free to remove the atoms of the nanometer material that are absent at the nucleation of the nanopore.
[0002]
Method according to claim 1, characterized in that the second energy beam is directed to the nanopore nucleation site for a second period of time that imposes a second dose of the beam, which causes the removal of a plurality of atoms of edge to form a nanopore in the nanometric material having a diameter of less than 1000Å.
[0003]
Method according to claim 1, characterized by the fact that the nanometric material is selected from the group consisting of graphenes, graphene with few layers, fluorographene, graphane and graphene oxide.
[0004]
Method according to claim 1, characterized by the fact that the nanometric material is selected from the group consisting of hexagonal BN, mono-atomic glasses, MoS2, WS2, MoSe2, MoTe2, TaSe2, NbSe2, NiTe2, Bi2Sr2CaCu2Ox and Bi2Te3.
[0005]
Method according to claim 1, characterized by the fact that it still comprises a first stage of placing the nanometric material in a support structure for processing by the first and second energy bundles.
[0006]
Method according to claim 5, characterized in that the support structure includes an opening through which the nanometric material extends.
[0007]
Method according to claim 6, characterized by the fact that the support structure comprises a grid for transmission electron microscope.
[0008]
Method according to claim 5, characterized by the fact that it still comprises a first stage of synthesis of the nanometric material and transfer of the synthesized material to the support structure.
[0009]
Method according to claim 1, characterized by the fact that it still comprises first placing on the nanometric material a standardized mask material that includes openings through which the energy beams can be directed to the nanometric material.
[0010]
Method according to claim 1, characterized by the fact that the first energy beam comprises an ion beam selected from the group of ion beams of argon, gallium, neon, hydrogen / protons and helium.
[0011]
Method according to claim 1, characterized by the fact that the first energy beam and the second energy beam are each ion beams.
[0012]
Method according to claim 1, characterized by the fact that the first energy beam is an ion beam and the second energy beam is an electron beam.
[0013]
Method according to claim 1, characterized by the fact that it still comprises the maintenance of the nanometric material at a temperature below 27 ° C (300 K) when the first energy beam is directed to the nanometric material.
[0014]
Method according to claim 13, characterized by the fact that it still comprises the maintenance of the nanometric material at a temperature less than -73 ° C (200 K) when the first energy beam is directed to the nanometric material.
[0015]
Method according to claim 1, characterized by the fact that it still comprises the maintenance of the nanometric material at a temperature below 27 ° C (300 K) when the second energy beam is directed to the nanometric material.
[0016]
Method according to claim 15, characterized by the fact that it still comprises the maintenance of the nanometric material at a temperature less than -73 ° C (200 K) when the second energy beam is directed to the nanometric material.
[0017]
Method according to claim 1, characterized by the fact that the formation of a nanopore comprises the formation of a nanopore having an extension that varies between 3 Å and 1,000 Å.
[0018]
Method according to claim 1, characterized by the fact that it still comprises the detection, when the second energy beam is directed to the nanometric material, of beam particles that are transmitted through a forming nanopore and control of the second energy beam in response detection to form a nanopore of a selected extent.
[0019]
Method according to claim 1, characterized in that the formation of a nanopore nucleation site comprises the formation of a matrix of nanopore nucleation sites and in which the formation of a nanopore at the nanopore nucleation site comprises the formation of a nanopore at each location in the matrix of nanopore nucleation sites.
[0020]
Method according to claim 19, characterized in that the formation of a matrix of nanopore nucleation sites comprises the formation of a matrix of nanopore nucleation sites having a density of at least 1,000 nanoporous nucleation sites / cm2 and wherein the formation of a nanopore comprises the formation of a nanopore at each location in the matrix of nanopore nucleation sites.
[0021]
Nanometric structure, characterized by the fact that it comprises: an impermeable self-supporting nanometric material, as defined in claim 1, said manometric material selected from graphenes, graphene with few layers, fluorographene, graphane and graphene oxide, and having a thickness of less than 5 nm; and a plurality of nanopores in the nanometric material, including at least 50 nanopores or a density of 1,000 nanopores / cm2, each nanopore having a diameter of less than 10 nm and the plurality of nanopores being of a monodispersed diameter with a variation of less than 30%.
[0022]
Nanometric structure according to claim 21, characterized by the fact that the nanometric material has a thickness less than 3 nm.
[0023]
Nanometric structure according to claim 21, characterized by the fact that each nanopore has a diameter less than 4 nm.

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同族专利:

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KR101979038B1|2019-05-15|

WO2012125770A3|2012-12-20|

AU2012229925A1|2013-10-03|

CN103702927B|2016-08-17|

CA2829833C|2019-04-09|

AU2012229925B2|2015-12-03|

US9611140B2|2017-04-04|

US10766762B2|2020-09-08|

US20170158487A1|2017-06-08|

AU2017216589B2|2019-07-04|

KR20140022837A|2014-02-25|

JP2016165794A|2016-09-15|

CA2829833A1|2012-09-20|

JP5902723B2|2016-04-13|

EP2686268B1|2018-05-09|

CN103702927A|2014-04-02|

JP2014515695A|2014-07-03|

WO2012125770A2|2012-09-20|

EP2686268A2|2014-01-22|

AU2016201323A1|2016-03-17|

AU2017216589A1|2017-09-07|

US20140079936A1|2014-03-20|

BR112013023586A2|2018-07-03|

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法律状态:
2019-07-16| B06T| Formal requirements before examination [chapter 6.20 patent gazette]|

2020-04-28| B07A| Technical examination (opinion): publication of technical examination (opinion) [chapter 7.1 patent gazette]|

2020-11-10| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|

2021-01-26| B16A| Patent or certificate of addition of invention granted|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 14/03/2012, OBSERVADAS AS CONDICOES LEGAIS. |

优先权:

申请号 | 申请日 | 专利标题

US201161452704P| true| 2011-03-15|2011-03-15|

US61/452,704|2011-03-15|

PCT/US2012/029132|WO2012125770A2|2011-03-15|2012-03-14|Controlled fabrication of nanopores in nanometric solid state materials|

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