• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to a Schottky diode (400) comprising: a conductive or semiconductor substrate (401) covered with a stack comprising, in order from a first surface of the substrate, a buffer layer (403), a first an N-type doped GaN layer (405), and a second N-type doped GaN layer (407) having a doping level lower than that of the first layer; a Schottky contact (409) on a first face opposite the substrate of the second GaN layer (407); and a first metallization (411) connecting to the substrate (401) a first face opposite to the substrate of the first GaN layer (405), said metallization (411) being located in an opening (410) located in an area of the stack uncoated by the Schottky contact (409), this opening (410) extending from the first face of the second layer (407) to the substrate (401).
    公开号:FR3017242A1
    申请号:FR1450886
    申请日:2014-02-05
    公开日:2015-08-07
    发明作者:Arnaud Yvon；Daniel Alquier；Yvon Cordier
    申请人:Centre National de la Recherche Scientifique CNRS；Rabelais Francois Universite de Tours；STMicroelectronics Tours SAS；
    IPC主号:
    专利说明:

    [0001] TECHNICAL FIELD The present application relates to a Schottky diode comprising a Schottky contact between a layer of gallium nitride (GaN) and a metal layer.
    [0002] DESCRIPTION OF THE PRIOR ART It has already been proposed to produce Schottky diodes using doped gallium nitride as a semiconductor material. In fact, gallium nitride has properties that make it particularly attractive, especially for high power applications. The known gallium nitride Schottky diode structures, however, have various disadvantages. There is a need for a gallium nitride Schottky diode to overcome all or some of these disadvantages.
    [0003] SUMMARY Thus, an embodiment provides a Schottky diode comprising: a conductive or semiconductor substrate covered with a stack comprising, in order from a first face of the substrate, a buffer layer, a first layer of GaN doped with N-type, and a second N-type doped GaN layer of doping level lower than that of the first layer; a Schottky contact on a first face opposite to the substrate of the second layer of GaN; and a first metallization connecting to the substrate a first face opposite to the substrate of the first GaN layer, said metallization being located in an opening located in a zone of the stack uncoated by the Schottky contact, this opening extending from the first face of the second layer to the substrate. According to one embodiment of the present invention, the diode further comprises a second metallization coating a second face of the substrate opposite to the first face of the substrate. According to one embodiment of the present invention, the opening comprises a first peripheral portion passing through the second GaN layer and opening on the first face of the first GaN layer, and a central portion passing through the two layers of GaN and the layer buffer, and extending to the substrate. According to one embodiment of the present invention, the aperture stops on the first face of the substrate.
    [0004] According to one embodiment of the present invention, the opening extends to an intermediate level of the substrate. According to one embodiment of the present invention, the substrate is made of silicon.
    [0005] According to one embodiment of the present invention, the first metallization is not intended to be connected to an external component. BRIEF DESCRIPTION OF THE DRAWINGS These and other features and advantages will be set forth in detail in the following description of particular embodiments in a non-limiting manner with reference to the accompanying figures in which: FIG. section schematically illustrating a first example of a gallium nitride Schottky diode; Fig. 2 is a sectional view schematically illustrating a second example of a gallium nitride Schottky diode; Fig. 3 is a sectional view schematically illustrating a third example of a gallium nitride Schottky diode; Fig. 4 is a sectional view schematically illustrating an example of an embodiment of a gallium nitride Schottky diode; Figs. 5A to 5C are sectional views schematically illustrating steps of an example of a method of making a gallium nitride Schottky diode; and Figs. 6A and 6B are sectional views schematically illustrating steps of another example of a method of making a gallium nitride Schottky diode. DETAILED DESCRIPTION For the sake of clarity, the same elements have been designated with the same references in the various figures and, moreover, as is customary in the representation of the integrated circuits, the various figures are not drawn to scale. In addition, in the following description, directional references such as "vertical", "horizontal", "lateral", "below", "above", "upper", "lower", "overcoming", "overlapping", etc., apply to oriented components as illustrated in corresponding sectional views, it being understood that, in practice, these components may be oriented differently. Figures 1 and 2 are sectional views schematically illustrating two examples of gallium nitride Schottky diodes. To produce such diodes, one starts from a crystalline substrate 101, for example sapphire (A1203), silicon or silicon carbide. In order to obtain a GaN mesh, an intermediate buffer layer 103, for example silicon nitride nitride, aluminum nitride or aluminum nitride, is formed on the upper surface of the substrate 101. gallium nitride. On the upper face of the buffer layer 103, an N-type (N +) strongly doped GaN layer 105 is grown by epitaxy, followed by a N-type lightly doped GaN 107 layer (N-). An electrode 109, for example made of tungsten, titanium-tungsten, tungsten nitride, titanium nitride, nickel, gold, nickel-gold, platinum, platinum-gold, platinum-nickel, etc., is then deposited on the upper face of the lightly doped GaN layer 107, to obtain a Schottky contact between the electrode 109 and the layer 107. A problem is related to the presence of an insulating or highly resistive buffer layer 103 between the substrate 101 and the Schottky contact 109, which makes it difficult to obtain a vertical diode between the substrate 101 and the Schottky contact 109.
    [0006] FIG. 1 represents a Schottky diode 100 of pseudo-vertical type. In the diode 100, the surface of the N-type lightly doped GaN layer 107 above the heavily doped N-type layer 105 is limited, so that a peripheral portion of the upper surface of the layer 105 is apparent. . An electrode 111 is formed on the apparent part of the upper face of the heavily doped GaN layer 105, to obtain an ohmic contact between the electrode 111 and the layer 105. To obtain a GaN layer 107 of limited extent compared to at the layer 105, it is possible, for example, to carry out a selective epitaxy above an unmasked part of the layer 105, or to etch the layer 107 after its formation. A disadvantage is that such a diode poses problems of size and complexity of assembly. In particular, the presence of the cathode electrode 111 on the side of the upper face of the diode increases the total area of the diode. In addition, the mounting of such a diode in an external device is more complex and / or expensive because of the fact that two separate contacts (anode and cathode) must be taken from the side of the same face (upper face) of the diode.
    [0007] FIG. 2 shows a Schottky diode 200 in which, after manufacture of the stack of layers 103, 105 and 107 on the upper face of the substrate 101, openings have been formed from the underside. of the substrate 101, these 5 openings passing through the entire substrate 101 and the buffer layer 103 to open into the layer 105 of heavily doped GaN type N. These openings are filled with a conductive material 201. A metallization 203 coating the underside of the The substrate 101 is in contact with the conductive material 201 and forms a cathode electrode of the diode 200. This type of structure has the disadvantage of having a particularly complex manufacturing process. In particular, the making of openings from the underside of the substrate 101 is relatively restrictive. In addition, making contacts on the underside of the GaN layer 105 (nitrogen face) can be tricky. Fig. 3 is a sectional view schematically illustrating another example of a gallium nitride Schottky diode 300. To produce such a diode, as in the examples of FIGS. 1 and 2, a substrate 101 (not visible in FIG. 3) is formed on which an intermediate buffer layer 103 is formed (not visible in FIG. 3). . A difference with the examples of FIGS. 1 and 2 is that, in the example of FIG. 3, the N-type (N-) lightly doped GaN layer 107 is grown epitaxially on the buffer layer 103 first. then the heavily doped N-type (N +) GaN layer 105. The order of formation of the layers 105 and 107 is therefore reversed with respect to the examples of FIGS. 1 and 2. The structure thus obtained is then assembled with a second substrate 301 which is highly conductive on the side of the heavily doped N-type layer 105. In the example shown, the substrate 301 comprises a highly doped silicon support 301a, coated with a metal layer 301b on its side of its face in contact with the layer 105. The substrate 101 and the buffer layer 103 are then eliminated. then a Schottky contact 109 is formed on the face of the N-type lightly doped layer 107 opposite the substrate 301. A metallization 303, coating the face of the substrate 301 opposite the layer 105, forms a cathode electrode of the diode 300.
    [0008] A disadvantage is that the realization of this type of structure is relatively complex because of the need to assemble several substrates. Fig. 4 is a sectional view schematically illustrating an example of an embodiment of a gallium nitride Schottky diode 400. To produce such a diode, one starts from a substrate 401 conductor or semiconductor. By way of nonlimiting example, the substrate 401 may be a heavily doped silicon substrate, for example a silicon substrate having a doping level greater than 10 19 atoms / cm 3 and preferably greater than 10 20 atoms / cm 3. To obtain a mesh with GaN, an intermediate buffer layer 403 is formed on the upper face of the substrate 401, for example made of silicon nitride, aluminum nitride or gallium nitride. On the upper face of the layer 403, an N-type doped GaN 405 layer of epitaxial growth of a first (N +) doping level, for example having a doping level between 1 * 1018 atoms / cm 3 and 5 * 1020 atoms / cm3, then a layer of N-type doped GaN 107 of a second level of (N-) doping lower than the first level, for example with a doping level between 1 * 1015 atoms / cm3 and 5 * 1016 atoms / cm3. An electrode 409, for example made of tungsten, titanium-tungsten, tungsten nitride, titanium nitride, nickel, gold, nickel-gold, platinum, platinum-gold, platinum-nickel, etc., is then deposited on the upper face. of the weaker-doped GaN layer 407, to obtain a Schottky contact between the electrode 409 and the layer 407. In one aspect, the diode 400 comprises a metallization 411 connecting the upper face of the GaN layer 405 to the substrate 401. The metallization 411 is located in an opening 410 extending in the stack formed by the layers 403, 405 and 407 from the upper face of the layer 407 to the substrate 401. The opening 410 and the metallization 411 are located in a zone of the stack 403-405-407 not coated by the Schottky contact 409. The opening 410 and the metallization 411 extend for example along a part or of the entire periphery of the contact Schottky 409. In this ex For example, the opening 410 comprises an upper part, passing through the GaN layer 407, and a lower, narrower part, passing through the GaN layer 405 and the buffer layer 403 and opening into or onto the substrate 401. Thus, a portion of the upper surface of the GaN layer 405 is accessible in a peripheral part of the opening 410 and a portion of an upper surface of the substrate 401 is accessible in a central part of the opening 410, these two surface portions being connected by the metallization 411. By way of non-limiting example, the metallization 411 is in Titanium-Aluminum, Titanium-Aluminum-Nickel-Gold, TitaniumAluminium-Platinum-Gold, Titanium-Aluminum-Titanium-Tungsten, Aluminum , Aluminum-Copper, or Aluminum-Silicon-Copper.
    [0009] In the example shown, a metallization 413, for example made of Titanium-Nickel-Gold or Alu-Nickel-Gold, assumes the underside of the substrate 401 and forms a cathode electrode of the diode 400. As an example, no the substrate 401 may have a thickness of between 90 and 500 μm, for example of the order of 150 to 250 μm, the buffer layer 403 may have a thickness of between 0.5 and 5 μm, the GaN layer strongly 405 may have a thickness between 0.5 and 5 pin, and the lightly doped GaN layer 407 may have a thickness of between 1 and 10 pin. An advantage of the diode 400 of Figure 4 is that it has a vertical structure which facilitates its mounting in an external device relative to a pseudovertical diode of the type described in connection with Figure 1.
    [0010] In addition, the structure of FIG. 4 makes it possible, with identical Schottky junction surfaces, to reduce the total area of the diode with respect to a structure of the type described with reference to FIG. 1. Indeed, the metallization 411 of the structure of Figure 4 not being intended to be connected to an external device but only to electrically connect the layer 405 to the substrate 401, it can, in practice, occupy a much smaller surface area than the cathode metallization 411 of FIG.
    [0011] In addition, the structure of FIG. 4 is considerably simpler to produce than vertical structures of the type described in relation with FIGS. 2 and 3. In fact, the embodiment of the structure of FIG. 4 does not include etching of the substrate. by the rear face (lower face) and does not include the assembly of several substrates. FIGS. AA to 5C are cross-sectional views schematically illustrating steps of an exemplary method for producing a Schottky diode of the type described with reference to FIG. 4. More particularly, FIGS. process for making the opening 410 of the structure of Figure 4, for receiving the metallization 411 connecting the upper face of the GaN layer 405 to an upper surface of the substrate 401. Figure aA shows a starting structure 25 comprising the substrate 401 and, coating substantially the entire surface of the substrate 401, a stack constituted by the buffer layer 403, the heavily doped GaN layer 405, and the lightly doped GaN layer 407. FIG. 5B represents a first etching step 30 during which the entire thickness of GaN layer 407 is removed in a peripheral portion of the stack, to form the upper part of the opening. FIG. 5C shows a second etching step in which the full thickness of GaN layer 405 and the entire thickness of buffer layer 403 are removed in part. the stack located facing a central portion of the opening formed in the previous step, so as to form the lower portion of the opening 410. In the example shown, during the second etching step, the opening 410 is extended to an intermediate level of the substrate 401. In this example, during the etching steps of FIGS. 5B and 5C, two etching masks having openings of different dimensions are used, to obtain an opening 410 presenting a lower part narrower than its upper part, in which a portion of the upper surface of the GaN layer 405 and a portion of an upper surface of the substrate 401 are made accessible for later use. connected by metallization 411.
    [0012] The other steps making it possible to achieve the structure of FIG. 4, in particular the steps of formation of the metallizations 409, 411 and 413, have not been detailed, the implementation of these steps being within the grasp of the man of the job.
    [0013] Figures 6A. and 6B are sectional views schematically illustrating steps of another exemplary method of making a Schottky diode of the type described in connection with FIG. 4. More particularly, FIGS. 6A and 6B show an example of a method making it possible to obtain the opening 410 of the structure of FIG. 4, intended to receive the metallization 411 connecting the upper face of the GaN layer 405 to an upper surface of the substrate 401. FIG. 6A represents a starting structure comprising the substrate 401 and, on the upper face of the substrate 401, a plurality of islands or blocks 601 disjoint (two islands in the example shown) each comprising a stack of a buffer layer 403, a heavily doped GaN layer of type N 405, and a lightly doped GaN layer of type N 407. To obtain such a structure, it is possible to deposit layers 403, 405 and 407 in a localized manner. B13125 -10-T000- For example, during the growth of layers 403, 405 and 407, a mask may be provided to prevent the growth of these layers in the separation zones between islands 601. From such a starting structure, For example, it is possible to provide, in and on each island 601, a Schottky diode of the type described in relation with FIG. 4. FIG. 6B represents an etching step during which the entire thickness of the GaN 407 layer is removed in a peripheral portion of each island 601, to form the upper part of the opening 410. The lower part of the opening 410, passing through the GaN layer 405 and opening onto the upper surface of the substrate 401, is formed by the region of separation between islands 601.
    [0014] The other steps making it possible to achieve the structure of FIG. 4, in particular the steps of formation of metallizations 409, 411 and 413, have not been detailed, the implementation of these steps being within man's reach. of career.
    [0015] Particular embodiments have been described. Various variations and modifications will be apparent to those skilled in the art. In particular, the embodiments described are not limited to the particular examples of aforementioned numerical values, particularly to the examples of layer thicknesses and doping levels. In addition, the described embodiments are not limited to the particular examples of materials mentioned above, in particular to achieve the metallizations 409, 411 and 413, the substrate 401 and the buffer layer 403.
    [0016] In addition, the described embodiments are not limited to the aforementioned examples of methods of manufacturing a diode of the type described in connection with FIG. 4.
    权利要求:
    Claims (6)
    [0001]
    REVENDICATIONS1. A Schottky diode (400) comprising: a conductive or semiconductor-covered substrate (401) having, in order from a first face of the substrate, a buffer layer (403), a first layer of GaN doped with N-type (405), and a second N-doped GaN layer (407) having a doping level lower than that of the first layer; a Schottky contact (409) on a first face opposite the substrate of the second GaN layer (407); and a first metallization (411) connecting to the substrate (401) a first face opposite to the substrate of the first GaN layer (405), said metallization (411) being located in an opening (410) located in an area of the stack uncoated by the Schottky contact (409), this opening (410) extending from the first face of the second layer (407) to the substrate (401).
    [0002]
    2. Schottky diode (400) according to claim 1, further comprising a second metallization (413) coating a second face of the substrate (401) opposite to the first face of the substrate (401).
    [0003]
    The Schottky diode (400) according to claim 1 or 2, wherein said opening (410) comprises a first peripheral portion passing through the second GaN layer (407) and opening onto the first face of the first GaN layer (405). , and a central portion passing through the two layers of GaN (405, 407) and the buffer layer (403), and extending to the substrate (401).
    [0004]
    The Schottky diode (400) according to any one of claims 1 to 3, wherein said opening (410) stops on the first face of the substrate (401).
    [0005]
    The Schottky diode (400) according to any one of claims 1 to 3, wherein said opening (410) extends to an intermediate level of the substrate (401) .B13125 - 10-T000-1124 12
    [0006]
    The Schottky diode (400) according to any one of claims 1 to 5, wherein the substrate (401) is silicon.
    类似技术:
    公开号 | 公开日 | 专利标题
    FR3017242A1|2015-08-07|VERTICAL SCHOTTKY DIODE WITH GALLIUM NITRIDE
    FR2992466A1|2013-12-27|Method for manufacturing e.g. LED device, involves forming insulating material portion on sides of p-type layer, active layer and portion of n-type layer, and exposing contact studs over another portion of n-type layer
    WO2004027878A2|2004-04-01|Quasi-vertical power semiconductor device on a composite substrate
    EP1670063B1|2007-08-01|Vertical unipolar device periphery
    EP1111688A1|2001-06-27|Schottky diode on silicon carbide substrate
    EP3347917B1|2019-10-30|Electroluminescent device with integrated light sensor
    EP3364466B1|2019-09-18|Device comprising a plurality of diodes
    EP3479409B1|2021-08-04|Optoelectronic device comprising three-dimensional diodes
    EP0275778B1|1990-08-16|Process for collectively cutting semiconductor devices in a chemical way, and device cut by this process
    EP3769339A1|2021-01-27|Led emissive display device and method for producing such a device
    FR2857506A1|2005-01-14|RECOVERY AND PROTECTION DIODE
    FR3010228A1|2015-03-06|PROCESS FOR TREATING A GALLIUM NITRIDE LAYER HAVING DISLOCATIONS
    FR3011385A1|2015-04-03|SCHOTTKY DIODE IN GALLIUM NITRIDE WITH GUARD RING
    EP3053201B1|2019-10-30|Optoelectronic device based on light-emitting diodes
    EP3364468B1|2019-05-22|Diode with improved electrical injection
    FR3068514B1|2019-08-09|OPTOELECTRONIC DEVICE
    EP3378098B1|2019-12-04|Heterojunction diode having an increased transient surge current
    EP3144977B1|2019-11-06|High-voltage gallium nitride schottky diode
    FR2963985A1|2012-02-24|Gallium nitride vertical Schottky diode, has heavily doped p-type and n-type gallium nitride guard rings respectively provided at peripheries of electrode and lightly doped layer, where electrode is arranged on lightly doped layer
    US11271117B2|2022-03-08|Stacked high-blocking III-V power semiconductor diode
    FR3086797A1|2020-04-03|ELECTRONIC CIRCUIT COMPRISING DIODES
    WO2020115426A1|2020-06-11|Multi-colour electroluminescent display device and method for manufacturing such a device
    FR3090999A1|2020-06-26|Method for manufacturing a semiconductor component based on a III-N compound
    EP3900055A1|2021-10-27|Optoelectronic device with pn junction
    FR2633454A1|1989-12-29|Device for affixing a beam to a semiconductor component and its method of manufacture
    同族专利:
    公开号 | 公开日
    US20150221782A1|2015-08-06|
    FR3017242B1|2017-09-01|
    CN104821341A|2015-08-05|
    CN204516775U|2015-07-29|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US20060108659A1|2004-11-25|2006-05-25|Matsushita Electric Industrial Co., Ltd.|Schottky barrier diode and diode array|
    US20100207232A1|2009-02-18|2010-08-19|Alpha & Omega Semiconductor, Inc.|Gallium Nitride Semiconductor Device With Improved Forward Conduction|
    CN102054875A|2010-10-29|2011-05-11|中山大学|Power type GaN base Schottky diode and manufacture method thereof|
    KR100348269B1|2000-03-22|2002-08-09|엘지전자 주식회사|Schottky Contact Method Using Ruthenium Oxide|
    FR2844099B1|2002-09-03|2005-09-02|Commissariat Energie Atomique|SEMICONDUCTOR DEVICE OF QUASI-VERTICAL POWER ON COMPOSITE SUBSTRATE|
    FR3017242B1|2014-02-05|2017-09-01|Stmicroelectronics Sas|VERTICAL SCHOTTKY DIODE WITH GALLIUM NITRIDE|FR3017242B1|2014-02-05|2017-09-01|StmicroelectronicsSas|VERTICAL SCHOTTKY DIODE WITH GALLIUM NITRIDE|
    CN106098797A|2016-06-30|2016-11-09|江苏能华微电子科技发展有限公司|A kind of diode expitaxial sheet and preparation method thereof|
    CN106098747A|2016-06-30|2016-11-09|江苏能华微电子科技发展有限公司|A kind of Schottky diode epitaxial wafer and preparation method thereof|
    CN106098796A|2016-06-30|2016-11-09|江苏能华微电子科技发展有限公司|Diode expitaxial sheet and preparation method thereof|
    CN106098794A|2016-06-30|2016-11-09|江苏能华微电子科技发展有限公司|Diode expitaxial sheet and preparation method thereof|
    CN106098795A|2016-06-30|2016-11-09|江苏能华微电子科技发展有限公司|A kind of diode expitaxial sheet and preparation method thereof|
    CN109473483A|2017-09-08|2019-03-15|世界先进积体电路股份有限公司|Semiconductor device and its manufacturing method|
    CN111192928B|2020-01-09|2021-08-13|西安交通大学|Vertical GaN Schottky device structure with high breakdown voltage and low reverse leakage|
    CN111933744B|2020-09-23|2021-01-12|同方威视技术股份有限公司|Schottky diode packaging structure and preparation method thereof|
    法律状态:
    2016-01-21| PLFP| Fee payment|Year of fee payment: 3 |
    2017-01-24| PLFP| Fee payment|Year of fee payment: 4 |
    2018-01-23| PLFP| Fee payment|Year of fee payment: 5 |
    2020-01-22| PLFP| Fee payment|Year of fee payment: 7 |
    2021-01-20| PLFP| Fee payment|Year of fee payment: 8 |
    2022-01-19| PLFP| Fee payment|Year of fee payment: 9 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1450886A|FR3017242B1|2014-02-05|2014-02-05|VERTICAL SCHOTTKY DIODE WITH GALLIUM NITRIDE|FR1450886A| FR3017242B1|2014-02-05|2014-02-05|VERTICAL SCHOTTKY DIODE WITH GALLIUM NITRIDE|
    US14/607,577| US20150221782A1|2014-02-05|2015-01-28|Vertical gallium nitride schottky diode|
    CN201510058744.3A| CN104821341A|2014-02-05|2015-02-04|Vertical gallium nitride schottky diode|
    CN201520079978.1U| CN204516775U|2014-02-05|2015-02-04|Schottky diode|
    [返回顶部]