WO2012043885A1 - Iii族窒化物半導体素子製造用基板の製造方法、iii族窒化物半導体自立基板またはiii族窒化物半導体素子の製造方法、およびiii族窒化物成長用基板 - Google Patents
Iii族窒化物半導体素子製造用基板の製造方法、iii族窒化物半導体自立基板またはiii族窒化物半導体素子の製造方法、およびiii族窒化物成長用基板 Download PDFInfo
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- WO2012043885A1 WO2012043885A1 PCT/JP2011/073154 JP2011073154W WO2012043885A1 WO 2012043885 A1 WO2012043885 A1 WO 2012043885A1 JP 2011073154 W JP2011073154 W JP 2011073154W WO 2012043885 A1 WO2012043885 A1 WO 2012043885A1
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- layer
- group iii
- substrate
- nitride semiconductor
- chromium
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- 239000000758 substrate Substances 0.000 title claims abstract description 228
- 239000004065 semiconductor Substances 0.000 title claims abstract description 158
- 150000004767 nitrides Chemical class 0.000 title claims abstract description 156
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 78
- CXOWYMLTGOFURZ-UHFFFAOYSA-N azanylidynechromium Chemical compound [Cr]#N CXOWYMLTGOFURZ-UHFFFAOYSA-N 0.000 claims abstract description 111
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims abstract description 90
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 87
- 239000011651 chromium Substances 0.000 claims abstract description 87
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims abstract description 72
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 72
- 239000013081 microcrystal Substances 0.000 claims abstract description 67
- 238000005121 nitriding Methods 0.000 claims abstract description 66
- 239000007789 gas Substances 0.000 claims abstract description 42
- 238000004544 sputter deposition Methods 0.000 claims abstract description 37
- 239000012159 carrier gas Substances 0.000 claims abstract description 30
- 229910001873 dinitrogen Inorganic materials 0.000 claims abstract description 29
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 24
- 239000002245 particle Substances 0.000 claims abstract description 20
- 238000000151 deposition Methods 0.000 claims abstract description 16
- 230000008021 deposition Effects 0.000 claims abstract description 15
- 238000002488 metal-organic chemical vapour deposition Methods 0.000 claims abstract 3
- 230000015572 biosynthetic process Effects 0.000 claims description 63
- 238000000034 method Methods 0.000 claims description 52
- 239000013078 crystal Substances 0.000 claims description 42
- 238000000926 separation method Methods 0.000 claims description 6
- 238000003486 chemical etching Methods 0.000 claims description 4
- 239000010408 film Substances 0.000 description 92
- 238000005755 formation reaction Methods 0.000 description 61
- 229910052594 sapphire Inorganic materials 0.000 description 46
- 239000010980 sapphire Substances 0.000 description 46
- 229910052751 metal Inorganic materials 0.000 description 38
- 239000002184 metal Substances 0.000 description 38
- 229910052757 nitrogen Inorganic materials 0.000 description 21
- 238000002441 X-ray diffraction Methods 0.000 description 20
- XCZXGTMEAKBVPV-UHFFFAOYSA-N trimethylgallium Chemical compound C[Ga](C)C XCZXGTMEAKBVPV-UHFFFAOYSA-N 0.000 description 17
- 238000002248 hydride vapour-phase epitaxy Methods 0.000 description 15
- 230000008569 process Effects 0.000 description 15
- XMPZTFVPEKAKFH-UHFFFAOYSA-P ceric ammonium nitrate Chemical compound [NH4+].[NH4+].[Ce+4].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O XMPZTFVPEKAKFH-UHFFFAOYSA-P 0.000 description 14
- 239000001257 hydrogen Substances 0.000 description 14
- 229910052739 hydrogen Inorganic materials 0.000 description 14
- 238000001816 cooling Methods 0.000 description 11
- 229910021529 ammonia Inorganic materials 0.000 description 10
- VLTRZXGMWDSKGL-UHFFFAOYSA-N perchloric acid Chemical compound OCl(=O)(=O)=O VLTRZXGMWDSKGL-UHFFFAOYSA-N 0.000 description 8
- 238000012545 processing Methods 0.000 description 8
- 238000001552 radio frequency sputter deposition Methods 0.000 description 8
- 239000011259 mixed solution Substances 0.000 description 7
- 238000000354 decomposition reaction Methods 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 5
- 238000005530 etching Methods 0.000 description 5
- 229910017604 nitric acid Inorganic materials 0.000 description 5
- -1 chrome nitride Chemical class 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 239000010409 thin film Substances 0.000 description 4
- 229910002704 AlGaN Inorganic materials 0.000 description 3
- XOYLJNJLGBYDTH-UHFFFAOYSA-M chlorogallium Chemical compound [Ga]Cl XOYLJNJLGBYDTH-UHFFFAOYSA-M 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical group [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 229910052733 gallium Inorganic materials 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- IXCSERBJSXMMFS-UHFFFAOYSA-N hcl hcl Chemical compound Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 235000002639 sodium chloride Nutrition 0.000 description 2
- 239000011780 sodium chloride Substances 0.000 description 2
- YZCKVEUIGOORGS-UHFFFAOYSA-N Hydrogen atom Chemical compound [H] YZCKVEUIGOORGS-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 125000004429 atom Chemical group 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000005234 chemical deposition Methods 0.000 description 1
- 238000005253 cladding Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000002019 doping agent Substances 0.000 description 1
- 238000001312 dry etching Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 239000012634 fragment Substances 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
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- 230000003287 optical effect Effects 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000010926 purge Methods 0.000 description 1
- 230000008707 rearrangement Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- 238000005477 sputtering target Methods 0.000 description 1
- 230000003685 thermal hair damage Effects 0.000 description 1
Images
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
- C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
- C23C14/14—Metallic material, boron or silicon
- C23C14/16—Metallic material, boron or silicon on metallic substrates or on substrates of boron or silicon
- C23C14/165—Metallic material, boron or silicon on metallic substrates or on substrates of boron or silicon by cathodic sputtering
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/10—Inorganic compounds or compositions
- C30B29/38—Nitrides
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- C—CHEMISTRY; METALLURGY
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- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
- C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
- C23C14/14—Metallic material, boron or silicon
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
- C23C14/58—After-treatment
- C23C14/5846—Reactive treatment
- C23C14/586—Nitriding
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
- C23C16/02—Pretreatment of the material to be coated
- C23C16/0272—Deposition of sub-layers, e.g. to promote the adhesion of the main coating
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- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
- C23C16/22—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the deposition of inorganic material, other than metallic material
- C23C16/30—Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
- C23C16/301—AIII BV compounds, where A is Al, Ga, In or Tl and B is N, P, As, Sb or Bi
- C23C16/303—Nitrides
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- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B25/00—Single-crystal growth by chemical reaction of reactive gases, e.g. chemical vapour-deposition growth
- C30B25/02—Epitaxial-layer growth
- C30B25/18—Epitaxial-layer growth characterised by the substrate
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02365—Forming inorganic semiconducting materials on a substrate
- H01L21/02436—Intermediate layers between substrates and deposited layers
- H01L21/02439—Materials
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02365—Forming inorganic semiconducting materials on a substrate
- H01L21/02436—Intermediate layers between substrates and deposited layers
- H01L21/02494—Structure
- H01L21/02496—Layer structure
- H01L21/02502—Layer structure consisting of two layers
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02365—Forming inorganic semiconducting materials on a substrate
- H01L21/02518—Deposited layers
- H01L21/02521—Materials
- H01L21/02538—Group 13/15 materials
- H01L21/0254—Nitrides
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/005—Processes
- H01L33/0062—Processes for devices with an active region comprising only III-V compounds
- H01L33/0066—Processes for devices with an active region comprising only III-V compounds with a substrate not being a III-V compound
- H01L33/007—Processes for devices with an active region comprising only III-V compounds with a substrate not being a III-V compound comprising nitride compounds
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/005—Processes
- H01L33/0093—Wafer bonding; Removal of the growth substrate
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- H—ELECTRICITY
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- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
- H01L33/26—Materials of the light emitting region
- H01L33/30—Materials of the light emitting region containing only elements of Group III and Group V of the Periodic Table
- H01L33/32—Materials of the light emitting region containing only elements of Group III and Group V of the Periodic Table containing nitrogen
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- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
- H01L33/20—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a particular shape, e.g. curved or truncated substrate
- H01L33/22—Roughened surfaces, e.g. at the interface between epitaxial layers
Definitions
- the present invention relates to a method for manufacturing a group III nitride semiconductor device manufacturing substrate, a group III nitride semiconductor free-standing substrate or a group III nitride semiconductor device manufacturing method, and a group III nitride growth substrate.
- a group III nitride semiconductor element composed of a group III nitride semiconductor made of a compound of Al, Ga, etc. and N is widely used as a light emitting element or an electronic device element.
- a group III nitride semiconductor is currently generally formed on a crystal growth substrate made of sapphire, for example, by MOCVD (Metal Organic Chemical Deposition).
- the group III nitride semiconductor and the crystal growth substrate have greatly different lattice constants, dislocation occurs due to the difference in the lattice constant, and the group III nitride grown on the crystal growth substrate. There exists a problem that the crystal quality of a semiconductor layer will fall.
- a method of growing a GaN layer on a sapphire substrate through a low-temperature polycrystalline or amorphous buffer layer is widely used.
- the sapphire substrate has low heat conductivity, heat dissipation is poor, and since it is insulative and cannot flow current, an n electrode and a p electrode are formed on one side of the nitride semiconductor device layer to flow current.
- This configuration is not suitable for producing a high-power light emitting diode (LED) because it is difficult for a large current to flow through this configuration.
- Non-Patent Document 1 and Patent Document 1 a growth layer is attached to another support substrate that is conductive and has high thermal conductivity, and laser light having a quantum energy larger than the energy gap of GaN is applied to the sapphire substrate.
- a method such as a laser lift-off method has been proposed in which a GaN layer is irradiated from the back surface thereof to thermally decompose into Ga and N, and the sapphire substrate and the group III nitride semiconductor layer are peeled off.
- these methods have problems that the cost of the laser lift-off device is high and that thermal damage is easily introduced into the device layer formed on the GaN layer to be peeled off.
- Patent Documents 2 to 5 disclose techniques in which a GaN layer is grown on a sapphire substrate via a metal nitride layer. According to this method, the dislocation density of the GaN layer can be reduced as compared with the buffer layer technology, and a high-quality GaN layer can be grown. This is because the difference in lattice constant and thermal expansion coefficient between the CrN film, which is a metal nitride layer, and the GaN layer is relatively small.
- the CrN film can be selectively etched with a chemical etching solution, and is useful in a process of separating the growth substrate and the group III nitride semiconductor device layer using a chemical lift-off method.
- a metal chromium layer formed on a growth (0001) sapphire substrate is used in a HVPE (Hydride Vapor Phase Epitaxy) apparatus.
- HVPE Hydrodride Vapor Phase Epitaxy
- a technique is disclosed in which nitriding treatment is performed at a temperature of 1000 ° C. or higher in an atmosphere containing ammonia gas to partially form triangular pyramid-shaped chromium nitride microcrystals as shown in FIG. ing.
- the crystal structure of chromium nitride is rock salt type (cubic), the bottom of the triangular pyramid is the (111) plane, and the bottom is [10-10], [01-10] in the sapphire substrate (0001) plane.
- the direction from the bottom center of gravity to the apex of the triangular pyramid is [111] as shown in the X-ray diffraction 2 ⁇ - ⁇ scan result of FIG.
- the nitriding treatment of the chromium layer is performed in the HVPE apparatus.
- the reason is that the nitriding treatment in the HVPE apparatus is a hot wall type, and the ammonia gas is heated before mixing with a group III chloride gas such as a group III raw material such as GaCl. Is good.
- thin film growth is indispensable for the formation of nitride semiconductor elements, but it is difficult to form a thin film of a nitride semiconductor layer in an HVPE growth furnace, and after forming a CrN layer in an HVPE furnace, However, there is a problem in that it is difficult to epitaxially grow a group III nitride semiconductor layer having good crystallinity on the CrN layer due to oxidation of the surface of the CrN layer.
- the [111] orientation of the chromium nitride layer must be aligned with the direction perpendicular to the growth (0001) sapphire substrate surface.
- the azimuth of in-plane rotation of the chrome nitride layer is uniform and a predetermined azimuth in the sapphire (0001) plane, the above-mentioned scale-like or amorphous microcrystals with various orientations are formed. The crystallinity and uniformity of the crystal layer may be reduced.
- the object of the present invention is to improve the area ratio of the substantially triangular pyramid-shaped chromium nitride microcrystals on the surface of the formed chromium nitride layer when the chromium layer is nitrided in the MOCVD growth furnace.
- Method of manufacturing substrate for manufacturing group III nitride semiconductor device capable of improving crystallinity and uniformity of crystal layer grown on layer, and manufacturing of group III nitride semiconductor free-standing substrate or group III nitride semiconductor device It is to provide a method.
- the gist of the present invention is as follows. (1) A film forming step for forming a chromium layer on a growth base substrate, a nitriding step for nitriding the chromium layer under a predetermined condition to form a chromium nitride layer, and on the chromium nitride layer And a crystal layer growth step of epitaxially growing at least one group III nitride semiconductor layer. A method of manufacturing a group III nitride semiconductor device manufacturing substrate, wherein the chromium layer is sputtered by a sputtering method.
- the film was formed in such a range that the film formation rate was in the range of 7 to 65 mm / second and the thickness was in the range of 50 to 300 mm, and the chromium nitride layer had an in-furnace pressure of 6.666 kPa to 66.66 kPa.
- a gas atmosphere containing ammonia gas is formed, and gas components other than ammonia gas in the gas atmosphere are nitrogenous.
- a carrier gas consisting of the gas and hydrogen gas, III-nitride semiconductor device manufacturing method of manufacturing a substrate, wherein the content ratio of the nitrogen gas accounts for the carrier gas is in the range of 60 to 100% by volume.
- the chrome layer is intermittently formed on a plurality of growth base substrates so that the average film formation rate is in the range of 1 to 10 liters / second, respectively (1) or (2) The manufacturing method of the board
- a method of manufacturing a group III nitride semiconductor free-standing substrate or a group III nitride semiconductor device comprising a separation step, wherein the chromium layer has a film formation rate of 7 to 65 ⁇ / min in a sputtering particle range region by sputtering.
- the film is formed to have a thickness in the range of 50 to 300 mm in a range of seconds, and the chromium nitride layer has an in-furnace pressure of 6.666 kPa or more and 66.66 k In a MOCVD growth furnace having a temperature of 1000 ° C.
- the gas component other than ammonia gas in the gas atmosphere is a carrier gas composed of nitrogen gas and hydrogen gas,
- the chromium layer is intermittently deposited on a plurality of growth base substrates so that the average deposition rate is in the range of 1 to 10 liters / second, respectively (6) or (7)
- a method for producing a group III nitride semiconductor self-supporting substrate or a group III nitride semiconductor device is a method for producing a group III nitride semiconductor self-supporting substrate or a group III nitride semiconductor device.
- a group III nitride growth substrate having a substrate and a chromium nitride layer on the substrate, the chromium nitride having a substantially triangular pyramid shape among the chromium nitride microcrystals on the surface of the chromium nitride layer
- the film is formed by appropriately setting the film forming conditions of the chromium layer formed on the growth base substrate and the nitriding conditions for nitriding the chromium layer in the MOCVD growth furnace.
- the proportion of the substantially triangular pyramid-shaped chromium nitride microcrystals on the surface of the chromium nitride layer can be improved, whereby a group III nitride semiconductor layer or a group III nitride semiconductor device that is continuously grown on the chromium nitride layer can be obtained.
- a method of manufacturing a substrate for manufacturing a group III nitride semiconductor device capable of improving crystallinity and uniformity of a crystal layer of a structural layer, and a method of manufacturing a group III nitride semiconductor free-standing substrate or a group III nitride semiconductor device can do.
- FIGS. 2 (a) to 2 (c) show surface SEM photographs of the sample when the chromium layer formed by sputtering on the sapphire (0001) substrate is nitrided in a MOCVD furnace under predetermined conditions.
- d) shows the result of an X-ray diffraction 2 ⁇ - ⁇ scan.
- 3 (a) to 3 (d) are schematic cross-sectional views for explaining a method for manufacturing a substrate for manufacturing a group III nitride semiconductor device according to the present invention.
- 4A and 4B are schematic perspective views of various sputtering apparatuses
- FIG. 4C is a schematic cross-sectional view of the sputtering apparatus shown in FIG. 4B.
- FIG. 5A and FIG. 5B are graphs for explaining the relationship between the film formation rate and the average film formation rate.
- FIGS. 6 (a) and 6 (b) show the relationship between the film formation rate of the chromium layer and the formation ratio of the substantially triangular pyramid-shaped chromium nitride microcrystals after nitriding, and the average composition of the chromium layer, respectively. It is a graph which shows the relationship between the film speed and the formation rate of the substantially triangular pyramid-shaped chromium nitride microcrystal after nitriding.
- FIG. 7A and FIG. 7B show surface SEM photographs of the sample after nitriding
- FIG. 7C shows the result of X-ray diffraction 2 ⁇ - ⁇ scan.
- FIG. 8A and 8B show SEM photographs showing the surface morphology of the chromium layer when the chromium layer on the sapphire substrate is heat-treated in a hydrogen / nitrogen mixed gas atmosphere and a nitrogen gas atmosphere, respectively.
- FIG. 9A is a graph showing the relationship between the ratio of nitrogen in the carrier gas and the area ratio occupied by the substantially triangular pyramid-shaped microcrystals.
- FIGS. 9B to 9F are graphs after nitriding treatment, respectively. The surface SEM photograph of this sample is shown.
- FIG. 10 shows an SEM photograph showing the furnace pressure during nitriding and the surface state of the chromium nitride layer after nitriding.
- FIG. 10 shows an SEM photograph showing the furnace pressure during nitriding and the surface state of the chromium nitride layer after nitriding.
- FIG. 11 shows an SEM photograph showing the surface state of the chromium nitride layer when the nitriding temperature and the processing time are changed when the carrier gas is total nitrogen.
- 12A to 12E are schematic cross-sectional views for explaining a group III nitride semiconductor device manufacturing substrate, a group III nitride semiconductor free-standing substrate, and a method for manufacturing a group III nitride semiconductor device according to the present invention. It is.
- FIGS. 13A and 13B are graphs showing the relationship between the deposition rate and average deposition rate of the chromium layer and the half width of the X-ray rocking curve of the GaN layer grown by the MOCVD method, respectively.
- FIG. 14B are diagrams showing the crystal orientation (epitaxial) relationship between the chromium nitride layer and the group III nitride semiconductor layer depending on the type of the underlying substrate.
- FIG. 15 is a graph showing the relationship between the thickness of the chromium layer and the half width of the X-ray rocking curve of the GaN layer grown by the MOCVD method.
- FIG. 16A and FIG. 16B are a result of X-ray diffraction 2 ⁇ - ⁇ scan and a surface SEM photograph of the sample after nitriding, respectively.
- the substrate for manufacturing a group III nitride semiconductor device in the present invention is a substrate obtained by growing at least one group III nitride semiconductor layer on a chromium nitride layer formed on a growth base substrate.
- a group III nitride semiconductor free-standing substrate is a growth substrate after a group III nitride semiconductor layer having a thickness of several hundred ⁇ m or more is grown on a chromium nitride layer formed on a base substrate for growth. This is obtained by separating the base substrate.
- the group III nitride semiconductor element refers to a group III nitride semiconductor element manufacturing substrate that has been subjected to a device process such as electrode evaporation to separate the elements, or a group III nitride semiconductor free-standing substrate A group III nitride semiconductor element structure layer is formed thereon, and a device process such as electrode deposition is performed to separate the elements.
- group III nitride semiconductors include, but are not limited to, GaN-based, InGaN-based, AlInGaN-based, and AlGaN-based semiconductors. Further, in this specification, the “layer” may be a continuous layer or a discontinuous layer. A “layer” represents a state formed with a thickness.
- FIGS. 3A to 3D are schematic cross-sectional views for explaining a method for manufacturing a group III nitride semiconductor device manufacturing substrate according to the present invention.
- a growth base substrate 10 is prepared.
- the growth base substrate 10 is a sapphire single crystal, and the surface 10a on the upper surface side of the growth base substrate is a (0001) plane.
- a single crystal of sapphire has a rhombohedral crystal structure and is a pseudo hexagonal system.
- the growth base substrate 10 may be a material other than sapphire as long as it has a pseudo hexagonal, hexagonal or cubic crystal structure.
- a template substrate in which an AlN epitaxial layer is formed on an AlN single crystal or various growth substrates may be used.
- the chromium layer 20 is formed on the surface 10a of the growth base substrate 10 at a predetermined speed.
- the chromium layer 20 is formed by a sputtering method, and the film formation rate in the range of the sputtered particle range is in the range of 7 to 65 liters / second.
- the atmosphere during sputtering is Ar gas having a pressure in the range of 0.05 to 0.5 Pa, but the pressure range may be appropriately adjusted depending on the apparatus configuration.
- the chromium layer 20 can be formed by RF (high frequency) or DC (direct current) sputtering, and the chromium layer 20 is formed to have a thickness in the range of 50 to 300 mm.
- the film As a sputtering device, there are cases where one or several substrates are set at opposing positions that are equal to or smaller than the target area, but in order to improve productivity, they are formed on a large number of substrate substrates for growth.
- the film is formed by rotating the substrate holding holder or the tray 130 with a carousel type shown in FIG. 4A or a parallel plate type as shown in FIG. 4B.
- the film is intermittently formed at a film formation speed as shown in FIG. A film is to be formed.
- the same number of films should be formed on each substrate, or even if the film formation rate per time is not reduced to reduce the difference in film formation amount. There is a need.
- An object of the present invention is to form a chromium nitride layer suitable for improving the crystallinity of a group III nitride semiconductor layer, which is not an irregular shape or a scale-like microcrystal close to a quadrangular shape but a triangular pyramid shape.
- the purpose is to form microcrystals uniformly over the entire surface of the base substrate.
- a sapphire (0001) substrate is set in a parallel plate type RF sputtering apparatus shown in FIG. 4B, and a high-frequency power source is adjusted so that an average film formation rate is 0.25 to 10 mm / second (the film formation rate is 1.65).
- a sample in which a chromium layer 20 was formed in a thickness of 120 ⁇ was prepared in a range of ⁇ 65.9 ⁇ / sec. The rotation speed of the tray was 20 rpm.
- the content ratio of ammonia gas is 25% by volume
- the flow rate is 6 SLM (Standard Litter Per Minute: flow rate converted to a flow rate at 0 ° C., 1 atm)
- hydrogen is a gas other than ammonia gas.
- the content ratio is 20% by volume and the content ratio of nitrogen is 55% by volume (the ratio of nitrogen gas to the carrier gas is about 73.3% by volume)
- the nitriding treatment is performed at a pressure of 26.664 kPa and a substrate temperature of 1080 ° C. for 10 minutes.
- the chromium layer 20 was changed to the chromium nitride layer 30 of FIG.
- the content ratio of ammonia gas is in the range of 5 volume% or more and 95 volume% or less. This is because when the content ratio is less than 5% by volume, the nitriding efficiency is lowered, and the nitriding time is prolonged. In addition, if it exceeds 95% by volume, the purge gas for preventing the inflow of ammonia gas cannot be sufficiently flowed for protection of the apparatus.
- the temperature rise rate was 30 ° C./min in a hydrogen and nitrogen mixed gas atmosphere, and the supply of ammonia gas was started when the temperature reached 600 ° C. In the cooling process, when the temperature reached 600 ° C., the supply of ammonia gas and hydrogen gas was stopped, and cooling was performed in a nitrogen gas atmosphere.
- 3C and 3D show the chromium nitride layer exaggerated as a continuous body having a substantially triangular cross section.
- the surface of the nitrided sample is observed with a scanning electron microscope (SEM), the shape of the chromium nitride microcrystals is observed, the proportion of the approximately triangular pyramid-shaped microcrystals in the sample surface, the deposition rate, and the average The relationship with the deposition rate was investigated.
- SEM scanning electron microscope
- the proportion of the substantially triangular pyramid-shaped microcrystals in the chromium nitride microcrystals formed in the sample plane is small, the proportion of the microcrystals determined to be substantially triangular pyramids in the SEM photograph is small. Triangular marks were overwritten, and the area ratio was calculated by image processing.
- the criterion for determining a substantially triangular pyramid is that the apex and ridge lines can be observed in three directions from the contrast resulting from the height of the SEM photograph.
- a ridge line is observed in addition to the merged portion. Therefore, it is expressed here as “substantially” triangular pyramid shape.
- FIG. 6A and FIG. 6B show the maximum and minimum ranges of the area ratio occupied by the substantially triangular pyramid-shaped microcrystals at the above-described 10 points for the respective film formation speed conditions.
- the film formation speed and the average film formation speed at the time of sputtering are slow, for example, the film formation speed of 1.65 ⁇ / second and the average film formation speed of 0.25 ⁇ ⁇ shown in FIG. 6A and FIG.
- the substantially triangular pyramid shape occupies most after nitriding as shown in the SEM photograph of FIG.
- the proportion of the fine crystals of substantially triangular pyramids accounted for about 97%.
- the black and white contrast of the SEM photograph is given due to the height of the large substantially triangular pyramid shape, but the black portion is not necessarily flat, and has a smaller substantially triangular pyramid shape at a higher magnification. Microcrystals are often observed.
- the area ratio is evaluated by the magnification of the SEM photograph of FIG.
- the film forming speed in the sputtering particle range region 140 is 7 ⁇ / second or more, and further the average film forming speed is 1 ⁇ / second or more.
- Scale-like and amorphous chrome nitride microcrystals near the surface of the crystal are drastically reduced, and as shown in the SEM photograph of FIG. 7B, the area ratio occupied by the substantially triangular pyramid-shaped microcrystals is 70% or more, 90% or more, Furthermore, it was found that it could be 95% or more. Further, the result of X-ray diffraction 2 ⁇ - ⁇ scan of the sample of FIG.
- the film forming speed is preferably low.
- the film forming speed is high in terms of good nitriding treatment suitable for the purpose of the present invention. It was issued.
- the thickness of the chromium layer is an appropriate value in the range of 50 to 300 mm (5 to 30 nm), and preferably in the range of 50 to 180 mm. If a film is formed, the film forming process time is 5 to less than 18 seconds, and there are restrictions on the number of rotations of the substrate holding holder or tray 130. At higher speeds, film thickness uniformity within the film forming batch is ensured. Therefore, the average film formation rate is preferably 8 ⁇ / second or less, and more preferably, the film formation rate in the sputtering particle range region 140 is 65 ⁇ / second or less.
- the average film formation rate is 10 liters / second or more in the chrome layer formation step.
- the average film formation rate is more preferably in the range of 1.8 ⁇ / second to 8 ⁇ / second, and the average film formation speed is more preferably in the range of 4 ⁇ / second to 8 ⁇ / second.
- the film formation rate in the sputtering particle range region 140 is set to be in a range of 7 ⁇ / second to 65 ⁇ / second.
- the nitriding treatment of the chromium layer has been performed in the HVPE apparatus.
- the nitriding treatment in the HVPE apparatus is a hot wall type, and ammonia gas is heated before mixing with a group III chloride gas such as GaCl, which is a group III raw material.
- a structure in which only the substrate portion is heated is employed, so that the decomposition efficiency of ammonia gas is poor, and the supply of atomic nitrogen mainly contributing to nitridation is less than in the HVPE method.
- the decomposition rate of ammonia gas in the thermal equilibrium state is about 1% at 800 ° C. and about 3% at 900 ° C.
- the growth of a thin film is indispensable for forming a nitride semiconductor device, and it is difficult to form a thin film of a nitride semiconductor layer in an HVPE furnace, and after forming a CrN layer in the HVPE furnace, it is necessary to move to a MOCVD furnace.
- epitaxial growth having good crystallinity on the CrN layer was difficult due to oxidation of the CrN layer surface at this time.
- the decomposition reaction of ammonia is 2NH 3 ⁇ N 2 + 3H 2 (Formula 1) It is considered that when ammonia is dissociated, atomic nitrogen and atomic hydrogen are once formed, and the atomic nitrogen has a dominant influence on the nitridation of the metal chromium layer.
- the thickness of the metal chromium layer on the sapphire substrate 10 is 120 mm
- the average film formation speed during sputtering film formation is 1.8 mm / second
- the film formation speed in the sputtering particle range region 140 is 18.1 mm / second.
- the content ratio of ammonia gas is 25% by volume
- the flow rate is 6 SLM
- the ratio of nitrogen gas in the mixed carrier gas of nitrogen and hydrogen is 0, 20, 44, 73, 100% by volume
- the substrate temperature is 1080 at a pressure of 26.664 KPa.
- Nitriding treatment was performed at a temperature of 10 ° C. for 10 minutes to form a chromium nitride layer 30 shown in FIG.
- the temperature rise rate was 30 ° C./min in a hydrogen and nitrogen mixed gas atmosphere, and the supply of ammonia gas was started when the temperature reached 600 ° C.
- the cooling process when the temperature reached 600 ° C., the supply of ammonia gas and hydrogen gas was stopped, and cooling was performed in a nitrogen gas atmosphere.
- Nitrided sample (2 to 3 sapphire substrates with 2 inch diameter under each condition) center of each substrate, 4 points 20 mm on each side, 5 surfaces in total with SEM (scanning electron microscope)
- the shape of the chromium nitride microcrystals was observed.
- the method for calculating the area ratio occupied by the substantially triangular pyramid-shaped microcrystals is as described above.
- FIG. 9A shows the relationship between the content ratio of nitrogen in the carrier gas and the area ratio occupied by the substantially triangular pyramid-shaped microcrystals. Here, the range of the maximum value and the minimum value of the sample observation points under each condition is shown.
- the content ratio of nitrogen in the carrier gas is 50% by volume or less, there is a large variation in the formation area ratio of the substantially triangular pyramid-shaped chromium nitride microcrystals at the position in the sample plane, but the ratio of nitrogen in the carrier gas is When it is 60% by volume or more, it can be seen that the variation in the sample surface is greatly reduced, and the substantially triangular pyramid-shaped chromium nitride microcrystals are uniformly formed in the surface relatively, and the area ratio is at least 70% or more. . Further, it can be seen that when the volume ratio is 70% by volume or more, a substantially triangular pyramid-shaped chromium nitride microcrystal is formed at an area ratio of 90% or more over the entire surface.
- nitrogen and hydrogen are used as a carrier gas as a gas component other than ammonia in a gas atmosphere containing ammonia gas in the nitriding step of the metal chromium layer in the MOCVD growth furnace, and the nitrogen content ratio is in the range of 60 to 100% by volume.
- the film forming rate when forming the metal chromium layer 10 described above to a predetermined value or more, among the chromium nitride microcrystals on the nitrided chromium nitride layer surface, a substantially triangular pyramid shape
- the area ratio occupied by the chromium nitride microcrystals can be 70% or more.
- a metal chromium layer having a thickness of 120 mm was formed on the sapphire substrate 10 having a diameter of 2 inches by a sputtering method.
- the average film formation rate during sputtering film formation was 1.8 ⁇ / second, and the film formation rate in the sputtering particle range 140 was 11.9 ⁇ /second.
- the content ratio of ammonia gas was 25% by volume, the flow rate was 6 SLM, the carrier gas was all nitrogen gas, and the nitriding treatment was performed at a substrate temperature of 1080 ° C. for 10 minutes to form the chromium nitride layer 30 of FIG. .
- the pressure inside the furnace was adjusted by adjusting the conductance on the exhaust side, and was set to the same pressure during temperature rising / nitriding / temperature decreasing under the conditions of 6.666 KPa, 26.664 KPa, 66.66 Kpa, 73.326 KPa, 99.99 KPa.
- the temperature rising rate was 30 ° C./min in a nitrogen gas atmosphere, and the supply of ammonia gas was started when the temperature reached 600 ° C. In the cooling process, when the temperature reached 600 ° C., the supply of ammonia gas was stopped and the system was cooled in a nitrogen gas atmosphere.
- the result of observing the form of the chromium nitride layer on the obtained sample surface with SEM is shown in FIG.
- the pressure in the furnace is 99.99 kPa
- the microcrystals having a substantially triangular pyramid shape are only partially formed and connected, but when the pressure is reduced to 73.326 kPa, a microcrystal having a substantially triangular pyramid shape appears. It starts but is still out of shape.
- the pressure in the furnace is 66.66 kPa or less, a substantially triangular pyramid-shaped microcrystal is formed uniformly. Accordingly, the proper pressure range in the furnace is 66.66 kPa or less.
- a metal chromium layer having a thickness of 120 mm was formed on the sapphire substrate 10 having a diameter of 2 inches by a sputtering method.
- the average film formation rate during sputtering film formation was 1.8 ⁇ / second, and the film formation rate in the sputtering particle range 140 was 11.9 ⁇ /second.
- the ammonia gas content ratio is 25% by volume
- the flow rate is 6 SLM
- the carrier gas is all nitrogen gas
- the substrate temperature is in the range of 900 ° C. to 1080 ° C.
- the treatment time is in the range of 10 minutes to 40 minutes
- the furnace pressure is It was set to 26.66 kPa.
- the temperature rise rate is 30 ° C./min in a nitrogen mixed gas atmosphere, and when the temperature reaches 600 ° C., the supply of ammonia gas is started, and a nitriding treatment is performed for a predetermined treatment time at the treatment temperature, The temperature was lowered at a cooling rate of 30 ° C./min. In the cooling process, when the temperature reached 600 ° C., the supply of ammonia gas was stopped and the system was cooled in a nitrogen gas atmosphere.
- FIG. 11 shows the result of observing the form of the chromium nitride layer with the SEM when the nitriding temperature and the processing time are changed.
- the nitriding treatment temperature is 900 ° C.
- the nitriding temperature is 1000 ° C.
- microcrystals having a substantially triangular pyramid shape start to form from an arabesque pattern, and in the treatment time of 40 minutes, the fine crystals of the substantially triangular pyramid are connected. It can be seen that crystals are formed.
- microcrystals having a substantially triangular pyramid shape are formed over the entire surface.
- the treatment time is lengthened, rearrangement of chromium nitride occurs on the surface, and the crystallite enlargement and the individual crystallites become discrete.
- the magnification is further increased at the time of SEM observation, there are many cases in which the crystallites having a substantially triangular pyramid shape having a small size are present even in discretely visible places.
- a nitriding temperature of 1000 ° C. or higher is preferable for forming a substantially triangular pyramid-shaped microcrystal.
- the above shows the preferred conditions regarding the formation conditions of the metal chromium layer 20 and the formation conditions of the chromium nitride layer 30 in the MOCVD furnace.
- the substrate temperature is lowered to 900 ° C., and after adjusting the ammonia gas flow rate, hydrogen gas flow rate, nitrogen gas flow rate, and pressure conditions, TMG (trimethylgallium) is added.
- TMG trimethylgallium
- a GaN buffer layer indicated by reference numeral 40 in FIG. 3D is formed in the furnace.
- the supply of TMG is once stopped, the gas flow rate and pressure conditions are changed, the temperature is raised to 1050 ° C., TMG is again introduced into the furnace, and the GaN layer 50 is grown.
- the TMG supply and the atmospheric gas conditions are adjusted and cooled to obtain a group III nitride semiconductor substrate.
- the supply of ammonia gas is continued up to 600 ° C. during temperature reduction.
- the layers denoted by reference numerals 40 and 50 in FIG. 3D may be AlN, AlGaN, or the like.
- the layer denoted by reference numeral 50 may have a multilayer structure having a semiconductor element structure.
- the substrate for manufacturing a group III nitride semiconductor device 90 of FIG. 12A selectively etches the chromium nitride layer 30 in the step shown in FIG.
- a liquid for example, a mixed solution of ceric ammonium nitrate and perchloric acid or nitric acid, and the growth base substrate 10 and the group III nitride semiconductor layers (40 and 50) are separated to form a group III nitride.
- the semiconductor free-standing substrate 150a can be obtained.
- a group III nitride semiconductor layer 60 is further grown on the group III nitride semiconductor device manufacturing substrate, and thus a group III nitride semiconductor device manufacturing substrate 90a as shown in FIG. 12B can be obtained.
- the group III nitride semiconductor layer 60 may be continuously grown in the MOCVD apparatus in which the group III nitride semiconductor layer 50 is grown, or may be taken out of the MOCVD apparatus and grown in another growth apparatus.
- the chromium nitride layer 30 is selectively dissolved in a selective etching solution, for example, a mixed solution of ceric ammonium nitrate and perchloric acid or nitric acid, in the step shown in FIG.
- group III nitride semiconductor free-standing substrate 150b can be obtained.
- the group III nitride semiconductor layer 50 of the group III nitride semiconductor device manufacturing substrate of FIG. 12A or the group III nitride semiconductor layer 60 of FIG. 12B has a multilayer structure having a semiconductor device structure.
- the growth base substrate 10 is removed by selectively dissolving the chromium nitride layer 30 as described above, and the individually separated group III nitride semiconductor device 160 as shown in FIG. Can be obtained.
- the device may be manufactured after removing the growth base substrate from the group III nitride semiconductor element manufacturing substrate, or the group III nitride semiconductor element manufacturing substrate may be manufactured.
- the growth surface side processing for example, the formation of the electrode 70 or the like, the element separation processing or the like is performed, the growth base substrate 10 is separated by dissolving the chromium nitride layer 30, and the electrode 80 or the like is formed on the separation surface. You may go.
- the above describes the substrate for manufacturing a group III nitride semiconductor device having a group III nitride semiconductor layer grown on a chromium nitride layer, a method for manufacturing a group III nitride semiconductor free-standing substrate, and an embodiment of the group III nitride semiconductor device.
- the relationship between the metal chromium film forming conditions and the crystallinity of the group III nitride semiconductor layer grown thereon will be described.
- the metal chromium layer 20 was formed to a thickness of 120 mm on the sapphire substrate (0001) substrate 10 by the RF sputtering method. At this time, samples were prepared in which the average film formation rate and the film formation rate in the sputtering particle range region 140 were in the range of 0.25 to 10 ⁇ / second and 1.65 to 65.9 ⁇ / second, respectively.
- the sample was set in an MOCVD apparatus, and the metal chromium layer 20 was nitrided at the substrate temperature of 1080 ° C. for 10 minutes by the above-described procedure.
- the content ratio of ammonia gas is 25% by volume and the flow rate is 6SLM.
- the content ratio of hydrogen is 20% by volume and the content ratio of nitrogen is 55% by volume (the ratio of nitrogen in the carrier gas) Was 73.3 vol%), and the total pressure was 26.664 KPa.
- the substrate temperature was lowered to 900 ° C., and after waiting for the system to stabilize for several minutes, the supply of TMG was started and the GaN buffer layer was grown to about 2.5 ⁇ m.
- the total pressure at this time was 86.658 kPa, and the raw material gas composition ratio (commonly referred to as V / III ratio) of Group V (ammonia) and Group III (Ga) was about 1000.
- the supply of TMG was once stopped, and the substrate temperature was raised to 1050 ° C. in a few minutes.
- FIG. 13 (b) shows the relationship between the average film formation rate of the metallic chromium layer and the respective half widths. Similarly, when the average film formation rate is lowered, the half width of the X-ray diffraction increases and the crystallinity is increased. It turns out that it falls.
- the required crystallinity varies depending on the type of product and the required characteristics, but the half-value width is 600 arcsec or less, more preferably 400 arcsec or less, and the narrower one is preferable. Therefore, it is appropriate that the deposition rate of the metallic chromium layer in the sputtering particle range region during the deposition of the metallic chromium layer is 7 ⁇ / second or more, more preferably 11 ⁇ / second or more, and further preferably 25 ⁇ / second or more. . Further, it is appropriate that the average film formation rate is 1 ⁇ / second or more, more preferably 1.8 ⁇ / second or more, and further preferably 4 ⁇ / second or more.
- the area ratio occupied by the substantially triangular pyramid-shaped fine crystals of chromium nitride shown in FIG. 6 (a) and FIG. 6 (b) is 70% or more, more preferably 90% or more, and still more preferably 95. It is consistent with the condition of% or more.
- Chromium nitride layer is not a scaly or indeterminate shape close to a quadrangle, but mainly a triangular pyramid shape, and the c-axis of GaN grown on it by aligning the orientation connecting the center of gravity and the apex of the bottom surface of the triangular pyramid It is thought that the fluctuation of the noise was reduced.
- the half width of the (10-12) diffraction is an index related to the rotational fluctuation of the crystal orientation in the c-plane, but the chromium nitride layer is not a scaly or indefinite shape close to a quadrangle, but a triangular pyramid shape.
- Rotation of the orientation in the c-plane of GaN grown on it by aligning the base of the triangular pyramid in a direction parallel to the m-axis ( ⁇ 10-10> direction group) in the c-plane of the sapphire substrate. It is thought that the fluctuation was reduced.
- the base substrate is a (0001) plane of AlN, SiC, GaN single crystal, or a template substrate in which a hexagonal (0001) layer of AlN, GaN, SiC, etc. is formed on various growth substrates
- an epitaxial substrate is used. The relationship is as shown in FIG. (0001) Hexagonal crystal // (111) CrN /// (0001) Group III nitride semiconductor layer And [11-20] Hexagonal // [10-1] CrN /// [11-20] Group III nitride semiconductor layer It becomes.
- the direction along the bottom of the triangular pyramid-shaped chromium nitride microcrystal is the ⁇ 10-1> direction group, and the orientation of the ⁇ 11-20> direction group of the group III nitride semiconductor crystal layer grown thereon is The feature is that they are always parallel regardless of the base substrate type.
- a sample was prepared by forming a metal chromium layer 20 on the sapphire (0001) substrate 10 by sputtering in a range of 0 mm (no chromium layer) to 500 mm.
- the average film formation speed was 4.5 ⁇ / second
- the film formation speed in the sputtering particle range was 29.7 ⁇ / second
- the rotation speed of the substrate tray 130 shown in FIG. 4B was 20 rpm. .
- the substrate temperature was lowered to 900 ° C., and after waiting for the system to stabilize for several minutes, the supply of TMG was started to grow the GaN buffer layer by about 2.5 ⁇ m.
- the total pressure at this time was 86.658 kPa, and the source gas composition ratio (commonly referred to as V / III ratio) of Group V (N in ammonia) and Group III (Ga) was about 1000.
- V / III ratio the source gas composition ratio (commonly referred to as V / III ratio) of Group V (N in ammonia) and Group III (Ga) was about 1000.
- the supply of TMG was once stopped, and the substrate temperature was raised to 1050 ° C. within a few minutes.
- the half width (FWHM) of the X-ray diffraction rocking curve (XRD) was measured on the (0002) diffraction surface and the (10-12) diffraction surface, and the crystallinity was evaluated.
- the results are shown in FIG. 15.
- the XRD half-value width on both diffraction surfaces is 600 arcsec or less, which is preferable in terms of crystallinity of the GaN layer, and more preferably 60 to 180 mm. It is a more preferable range.
- the thickness of the metal chromium layer was 0 mm, the GaN buffer layer did not grow on the sapphire substrate during the GaN buffer growth at 900 ° C. This is presumably due to the absence of early growth nuclei.
- Patent Document 3 When nitriding a metal chromium layer in a MOCVD furnace and subsequently growing a GaN layer of a group III nitride semiconductor, the appropriate range of the thickness of the metal chromium layer is thinner than in the case of the HVPE method (Patent Document 3) Is considered to reflect the difference in the nitriding state between the two manufacturing methods, the difference in the deposition rate of GaN, the difference in the lateral growth due to the surface migration of group III atoms on the growth surface, etc. Details are unknown.
- the thickness of the metal chromium layer was 40 mm or less. Etching did not proceed, and the GaN layer and sapphire substrate could not be separated by chemical lift-off (CLO).
- the thickness of the metal chromium layer was 50 mm or more, the GaN layer could be separated by selective etching of the chromium nitride layer.
- the exposure rate of the surface of the underlying sapphire substrate increases, and when the GaN layer with the chromium nitride layer as the initial growth nucleus grows in the lateral direction, the surface of the sapphire substrate and the GaN layer come into direct contact. This is probably because of this. Also in terms of chemical lift-off, the lower limit of the thickness of the metal chromium layer in the MOCVD method is 50 mm or more.
- the deposition rate condition of the metal chromium layer, the gas species condition during nitriding, the triangular pyramid As described above, in order to enable chemical lift-off in the MOCVD method and to improve the crystallinity of the group III nitride semiconductor layer, the deposition rate condition of the metal chromium layer, the gas species condition during nitriding, the triangular pyramid.
- the feature of the relationship between the orientation of the chrome nitride microcrystal of the shape and the orientation relationship of the group III nitride semiconductor crystal has been described with respect to the thickness condition of the metal chromium layer. The invention is not limited to this embodiment.
- Example 1 In the procedure described above, an average film formation rate of 4.5 ⁇ / sec (deposition rate in the sputtering particle range region is 29.7 ⁇ / sec) on a 2-inch sapphire (0001) substrate by RF sputtering, After forming a metal chromium layer having a thickness of 120 mm, a nitriding treatment was performed in a MOCVD furnace at a substrate temperature of 1080 ° C. for 10 minutes. At that time, the content ratio of ammonia gas is 25% by volume, the flow rate is 6SLM, and the carrier gas other than ammonia gas is 20% by volume of hydrogen and 55% by volume of nitrogen (the content of nitrogen gas in the carrier gas).
- the ratio was 73.3 vol%) and the total pressure was 26.664 kPa.
- the substrate temperature was lowered to 900 ° C., and the GaN buffer layer was grown to about 2.5 ⁇ m, and then heated to 1050 ° C. to grow the GaN layer to about 3 ⁇ m.
- the total pressure in the growing furnace was 86.658 kPa, and the raw material gas composition ratio (commonly called V / III ratio) of Group V (N in ammonia) and Group III (Ga) was about 1000.
- the substrate was cooled to near room temperature to obtain a group III nitride semiconductor substrate having a GaN epitaxial layer.
- the substrate sample was set in an HVPE furnace, heated at a heating rate of about 30 ° C./min in a hydrogen atmosphere, and when the temperature reached 600 ° C., supply of ammonia gas was started. Wait for the temperature of the system to stabilize at 1040 ° C. for about 5 minutes, start supplying hydrochloric acid (HCl) gas to the Ga source heated to 850 ° C. to generate GaCl, and mix with ammonia gas before the substrate. Gas was supplied to the substrate surface, and GaN thick film growth was started.
- HCl hydrochloric acid
- the flow rate of ammonia gas is 1 SLM
- the flow rate of hydrochloric acid (HCl) gas is 40 SCCM (Standard cm 3 / min: flow rate converted to atmospheric pressure 1.013 Pa, 0 ° C.)
- the flow rate of hydrogen carrier gas is 3.3 SLM
- V The / III ratio was 25 and the total pressure was a normal pressure of 101.3 kPa.
- the sample was separated from the sapphire substrate by selective etching of the chromium nitride layer in a mixed solution of ceric ammonium nitrate and perchloric acid heated to 80 ° C., and a 40 mm ⁇ free-standing substrate could be obtained. .
- the half width of XRD of the obtained free-standing substrate was very good at 85 arcsec and 103 arcsec in (0002) diffraction and (10-12) diffraction, respectively. (Corresponding to the process up to FIG. 12D)
- an optical device such as a laser diode or an electronic device such as a Schottky barrier diode can be produced.
- a freestanding substrate of a group III nitride semiconductor having good characteristics can be easily obtained.
- Example 2 A 120 mm thick metal chromium layer was formed on a 2 inch sapphire (0001) substrate by an RF sputtering method at an average film formation rate of 4.5 mm / sec.
- the sample was nitrided in a MOCVD furnace at a substrate temperature of 1080 ° C. for 10 minutes. Thereafter, the substrate temperature was lowered to 900 ° C., and the GaN buffer layer was grown to about 2.5 ⁇ m, and then heated to 1050 ° C. to grow the GaN layer to about 4 ⁇ m.
- Si silicon
- the carrier concentration was set to 2 ⁇ 10 18 cm ⁇ 3 .
- an In 0.1 Ga 0.9 N / GaN MQW (multiple quantum well) as a light emitting layer was formed while raising and lowering the substrate temperature in the range of 750 ° C. to 850 ° C.
- an Mg-doped p-type AlGaN electron blocking layer is grown to 20 nm
- an Mg-doped p-type GaN cladding layer is grown to 0.2 ⁇ m
- a p + -type GaN contact layer having a carrier concentration of 5 ⁇ 10 17 cm ⁇ 3 is formed to about 100 ⁇ m.
- a Group III nitride semiconductor epitaxial substrate having an LED structure was obtained.
- the obtained epitaxial substrate was dry-etched from the epitaxial layer side to the sapphire substrate to perform 1 mm square element isolation groove processing. This groove becomes a channel for supplying a chemical etching solution as well as separation between elements.
- an Ag-based reflective layer / ohmic electrode was formed on the p + GaN layer, and was bonded to a p + type Si substrate having an ohmic electrode formed on the back surface by an Au—Au pressure thermocompression bonding method at 300 ° C.
- the chromium nitride layer was selectively etched in a mixed solution of ceric ammonium nitrate and nitric acid heated to 80 ° C., the sapphire substrate was separated, and the LED structure layer was transferred to the Si support substrate side.
- the Si support substrate is cut with a dicer to produce a vertical structure LED element did. (This example corresponds to the process from FIG. 12A and FIG. 12B to FIG. 12E.)
- the characteristics of the obtained blue LED element in the bare chip state are as follows.
- the forward current (I f ) is 350 mA
- the forward voltage (V f ) is 3.3 V
- the peak emission wavelength ( ⁇ p ) is 455 nm
- the output (P o ) was 320 mW, a very good result.
- a group III nitride semiconductor epitaxial substrate having good characteristics which can be continuously performed in a MOCVD furnace from nitriding to LED structure epitaxial, and a group III nitride obtained by processing the same.
- a semiconductor device can be easily obtained.
- Example 3 An AlN (0001) template substrate was prepared in which an AlN epitaxial layer was directly formed on a 2-inch sapphire (0001) substrate.
- the thickness of the AlN layer was about 1 ⁇ m, and the half width of XRD was 85 arcsec and 1283 arcsec for (0002) diffraction and (10-12) diffraction, respectively.
- a 90 mm metallic chromium layer was formed on the sample by RF sputtering at an average film forming speed of 4.5 kg / sec.
- the sample was set in a MOCVD furnace, heated at a rate of 30 ° C./min, and subjected to nitriding treatment at 1050 ° C. for 5 minutes.
- the nitriding temperature and time are different from those on a sapphire substrate.
- an AlN intermediate layer is formed between the chrome layer and the substrate surface is an AlN single crystal from the beginning. This is because the formation thereof is unnecessary, and a triangular pyramid-shaped chromium nitride layer is formed even at a low temperature and for a short time.
- the ammonia gas supply was started at 600 ° C., the content ratio was 25% by volume, and the flow rate was 6 SLM. Nitrogen gas was used as a carrier gas other than ammonia gas, and the total pressure was 26.664 kPa.
- the substrate temperature was lowered to 900 ° C.
- the temperature of the system was stabilized
- the gas system was prepared for switching
- the supply of TMG was started after about 3 minutes to form a GaN buffer layer of about 2.5 ⁇ m.
- the total pressure at this time was 650 Torr (86.658 KPa), and the composition gas ratio (commonly called V / III ratio) of Group V (N in ammonia) and Group III (Ga) was about 1000.
- the supply of TMG was once stopped, and the substrate temperature was raised to 1050 ° C. within a few minutes.
- the XRD half-width was 120 arcsec and 218 arcsec, which were very good.
- the in-plane rotational azimuth fluctuation of the used AlN (0001) template was significantly improved without being inherited.
- a fragment was cut out from the sample, and the chromium nitride layer was selectively etched in a mixed solution of ceric ammonium nitrate and nitric acid heated to 80 ° C., and separation of the AlN template substrate and the GaN layer was confirmed. (This corresponds to the process from FIG. 12A to FIG. 12C.)
- An AlN (0001) template substrate having an XRD half width substantially equivalent to the above was separately prepared, and a metal chromium layer of 50 mm was formed by RF sputtering at an average film formation rate of 4.5 mm / sec.
- the same nitriding treatment as described above was performed in the MOCVD apparatus, and then cooling was performed without growing GaN, and a sample was taken out near room temperature. The supply of ammonia gas was stopped when the temperature became 600 ° C. or lower during cooling.
- the chromium nitride has a [111] orientation perpendicular to the AlN (0001) plane, as shown in FIG.
- a triangular pyramid-shaped microcrystal is formed as shown in FIG. 16 (b)
- the direction of the base of the crystal is very small
- the ⁇ 11-20> direction group of AlN It turns out that it is in the state along a parallel direction.
- the in-plane rotational orientation fluctuation of the AlN (0001) template is alleviated by the chromium nitride layer, the in-plane rotational orientation fluctuation of the GaN layer is greatly improved, and III having excellent crystallinity is obtained.
- a substrate for manufacturing a group nitride semiconductor device is obtained.
- a metal chromium layer having a thickness of 120 mm was formed by RF sputtering under the conditions of an average film forming speed of 0.5 kg / sec and a film forming speed of 3.3 kg / sec in the sputtering particle range region.
- nitriding was performed in a MOCVD furnace at a substrate temperature of 1080 ° C. for 10 minutes. Thereafter, the substrate temperature was lowered to 900 ° C., and the GaN buffer layer was grown to about 2.5 ⁇ m, and then heated to 1050 ° C. to grow the GaN layer to about 3 ⁇ m. After the growth, the semiconductor substrate was cooled to near room temperature to obtain a semiconductor substrate having a GaN epitaxial layer.
- Example 2 A metal chromium layer is formed on a sapphire (0001) substrate with a thickness of 25 mm and 500 mm by RF sputtering under the conditions of an average film formation rate of 4.5 mm / second and a film formation speed of 29.7 mm / second in the sputtering particle range region. Filmed. At this time, the rotation speed of the substrate tray was 30 rpm.
- nitriding was performed in a MOCVD furnace at a substrate temperature of 1080 ° C. for 10 minutes. Thereafter, the substrate temperature was lowered to 900 ° C., and the GaN buffer layer was grown to about 2.5 ⁇ m, and then heated to 1050 ° C. to grow the GaN layer to about 3 ⁇ m. After the growth, the semiconductor substrate was cooled to near room temperature to obtain a semiconductor substrate having a GaN epitaxial layer.
- the chromium nitride layer can be selectively etched in a mixed solution of ceric ammonium nitrate and nitric acid heated to 80 ° C. In other words, it was impossible to separate the sapphire substrate and the GaN layer.
- the film is formed by appropriately setting the film forming conditions of the chromium layer formed on the growth base substrate and the nitriding conditions for nitriding the chromium layer in the MOCVD growth furnace.
- the proportion of the substantially triangular pyramid-shaped chromium nitride microcrystals on the surface of the chromium nitride layer can be improved, whereby a group III nitride semiconductor layer or a group III nitride semiconductor device that is continuously grown on the chromium nitride layer can be obtained.
- a method of manufacturing a substrate for manufacturing a group III nitride semiconductor device capable of improving crystallinity and uniformity of a crystal layer of a structural layer, and a method of manufacturing a group III nitride semiconductor free-standing substrate or a group III nitride semiconductor device can do.
- Base substrate for growth 10a Surface of upper surface of base substrate 20 Metal chromium layer 30 Chromium nitride layer 40 Group III nitride semiconductor buffer layer 50 Group III nitride semiconductor layer 60 Group III nitride semiconductor layer 70 Electrode 80 Electrode 90 III Substrate for manufacturing group nitride semiconductor device 90a Substrate for manufacturing group III nitride semiconductor device 110 Substrate for growth 120 Sputtering target 130 Substrate holder or substrate tray 140 Sputtering particle range 150a Group III nitride semiconductor free-standing substrate 150b Group III nitride Semiconductor free-standing substrate 160 Group III nitride semiconductor device
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Abstract
Description
(1)成長用下地基板上に、クロム層を形成する成膜工程と、該クロム層を、所定の条件で窒化することによりクロム窒化物層とする窒化工程と、該クロム窒化物層上に、少なくとも1層のIII族窒化物半導体層をエピタキシャル成長させる結晶層成長工程とを具えるIII族窒化物半導体素子製造用基板の製造方法であって、前記クロム層は、スパッタリング法により、スパッタリング粒子飛程領域における成膜速度が7~65Å/秒の範囲で、厚さが50~300Åの範囲となるよう成膜され、前記クロム窒化物層は、炉内圧力6.666kPa以上66.66kPa以下の、温度1000℃以上のMOCVD成長炉内において、アンモニアガスを含むガス雰囲気中で形成され、前記ガス雰囲気中のアンモニアガス以外のガス成分は、窒素ガスおよび水素ガスからなるキャリアガスとし、該キャリアガスに占める窒素ガスの含有比率は60~100体積%の範囲であることを特徴とするIII族窒化物半導体素子製造用基板の製造方法。
2NH3 ⇔ N2 + 3H2 ・・・(式1)
の式で表記されるが、アンモニアが解離した際には、一旦原子状窒素と原子状水素が形成され、原子状窒素が金属クロム層の窒化に支配的な影響を与えるものと考えられる。
(0001)サファイア//(111)CrN//(0001)III族窒化物半導体層
ならびに、
〔1−100〕サファイア//〔10−1〕CrN//〔11−20〕III族窒化物半導体層
となる。
(0001)六方晶//(111)CrN//(0001)III族窒化物半導体層
ならびに、
〔11−20〕六方晶//〔10−1〕CrN//〔11−20〕III族窒化物半導体層
となる。
前記に記載した手順で、2インチ口径のサファイア(0001)基板上にRFスパッタリング法により平均成膜速度4.5Å/秒(スパッタリング粒子飛程領域における成膜速度は29.7Å/秒)で、120Å厚みの金属クロム層を成膜したのち、MOCVD炉内で基板温度1080℃、10分間の窒化処理を行った。その際の、アンモニアガスの含有比率は25体積%で流量は6SLM、アンモニアガス以外のキャリアガスとして水素は含有比率が20体積%ならびに窒素は含有比率が55体積%(キャリアガス中の窒素ガスの比率は73.3体積%)とし、全圧力は26.664kPaとした。その後基板温度を900℃まで降温し、GaNバッファ層を約2.5μm成長した後、1050℃まで昇温してGaN層を約3μm成長した。なお、成長中の炉内の全圧力は86.658kPa、V族(アンモニア中のN)とIII族(Ga)の原料ガス組成比(通称V/III比)は約1000とした。成長終了後室温近傍まで冷却し、GaNエピタキシャル層を有するIII族窒化物半導体基板を得た。GaN層の(0002)回折および(10−12)回折のX線ロッキングカーブ(XRD)の半値幅によって結晶性を評価した結果、各々290arcsec、330arcsecであり結晶性は良好であった。(図12(a)までの工程に相当)
2インチ口径のサファイア(0001)基板上にRFスパッタリング法により平均成膜速度4.5Å/秒で、120Å厚みの金属クロム層を成膜した。当該試料をMOCVD炉内で基板温度1080℃、10分間の窒化処理を行った。その後基板温度を900℃まで降温し、GaNバッファ層を約2.5μm成長した後、1050℃まで昇温してGaN層を約4μm成長した。GaNバッファ層上のGaN層にはSi(シリコン)をn型ドーパントして添加し、キャリア濃度を2×1018cm−3とした。
2インチ口径のサファイア(0001)基板上に直接AlNエピタキシャル層を形成した、AlN(0001)テンプレート基板を準備した。AlN層の厚みは約1μmで、XRDの半値幅は(0002)回折、(10−12)回折で各々85arcsec、1283arcsecであった。当該試料にRFスパッタリング法で平均成膜速度4.5Å/秒の条件で金属クロム層を90Å成膜した。
サファイア(0001)基板上に、RFスパッタリング法により平均成膜速度0.5Å/秒、スパッタリング粒子飛程領域における成膜速度3.3Å/秒の条件で金属クロム層を120Å成膜した。実施例1と同様、MOCVD炉内で基板温度1080℃、10分間の窒化処理を行った。その後基板温度を900℃まで降温し、GaNバッファ層を約2.5μm成長した後、1050℃まで昇温してGaN層を約3μm成長した。成長終了後室温近傍まで冷却し、GaNエピタキシャル層を有する半導体基板を得た。
サファイア(0001)基板上に、RFスパッタリング法により平均成膜速度4.5Å/秒、スパッタリング粒子飛程領域における成膜速度29.7Å/秒の条件で金属クロム層を25Åならびに500Åの厚みで成膜した。この際、基板トレーの回転数は30rpmとした。実施例1と同様、MOCVD炉内で基板温度1080℃、10分間の窒化処理を行った。その後基板温度を900℃まで降温し、GaNバッファ層を約2.5μm成長したのち、1050℃まで昇温してGaN層を約3μm成長した。成長終了後室温近傍まで冷却し、GaNエピタキシャル層を有する半導体基板を得た。
10a 下地基板の上面側の表面
20 金属クロム層
30 クロム窒化物層
40 III族窒化物半導体バッファ層
50 III族窒化物半導体層
60 III族窒化物半導体層
70 電極
80 電極
90 III族窒化物半導体素子製造用基板
90a III族窒化物半導体素子製造用基板
110 成長用下地基板
120 スパッタリングターゲット
130 基板ホルダーもしくは基板トレー
140 スパッタリング粒子飛程領域
150a III族窒化物半導体自立基板
150b III族窒化物半導体自立基板
160 III族窒化物半導体素子
Claims (11)
- 成長用下地基板上に、クロム層を形成する成膜工程と、
該クロム層を、所定の条件で窒化することによりクロム窒化物層とする窒化工程と、
該クロム窒化物層上に、少なくとも1層のIII族窒化物半導体層をエピタキシャル成長させる結晶層成長工程と
を具えるIII族窒化物半導体素子製造用基板の製造方法であって、
前記クロム層は、スパッタリング法により、スパッタリング粒子飛程領域における成膜速度が7~65Å/秒の範囲で、厚さが50~300Åの範囲となるよう成膜され、
前記クロム窒化物層は、炉内圧力6.666kPa以上66.66kPa以下の、温度1000℃以上のMOCVD成長炉内において、アンモニアガスを含むガス雰囲気中で形成され、前記ガス雰囲気中のアンモニアガス以外のガス成分は、窒素ガスおよび水素ガスからなるキャリアガスとし、該キャリアガスに占める窒素ガスの含有比率は60~100体積%の範囲であることを特徴とするIII族窒化物半導体素子製造用基板の製造方法。 - 前記クロム窒化物層表面の窒化クロム微結晶のうち、略三角錐形状を有する窒化クロム微結晶の占める面積比率が、70%以上である請求項1に記載のIII族窒化物半導体素子製造用基板の製造方法。
- 前記クロム層は、複数の成長用下地基板上に、それぞれ平均成膜速度が1~10Å/秒の範囲となるよう間欠的に成膜される請求項1または2に記載のIII族窒化物半導体素子製造用基板の製造方法。
- 前記略三角錐形状の窒化クロム微結晶の底辺の方位が、前記III族窒化物半導体層の<11−20>方向(a軸方向)群に平行である請求項2または3に記載のIII旌窒化物半導体素子製造用基板の製造方法。
- 前記成長用下地基板は、六方晶系または擬似六方晶系の結晶構造を有し、表面が(0001)面である請求項1~4のいずれか一項に記載のIII族窒化物半導体素子製造用基板の製造方法。
- 成長用下地基板上に、クロム層を形成する成膜工程と、
該クロム層を、所定の条件で窒化することによりクロム窒化物層とする窒化工程と、
該クロム窒化物層上に、少なくとも1層のIII族窒化物半導体層をエピタキシャル成長させる結晶層成長工程と、
前記クロム窒化物層をケミカルエッチングで除去することにより、前記成長用下地基板と前記III族窒化物半導体とを分離させる分離工程と
を具えるIII族窒化物半導体自立基板またはIII族窒化物半導体素子の製造方法であって、
前記クロム層は、スパッタリング法により、スパッタリング粒子飛程領域における成膜速度が7~65Å/秒の範囲で、厚さが50~300Åの範囲となるよう成膜され、
前記クロム窒化物層は、炉内圧力6.666kPa以上66.66kPa以下の、温度1000℃以上のMOCVD成長炉内において、アンモニアガスを含むガス雰囲気中で形成され、前記ガス雰囲気中のアンモニアガス以外のガス成分は、窒素ガスおよび水素ガスからなるキャリアガスとし、該キャリアガスに占める窒素ガスの含有比率は60~100体積%の範囲であることを特徴とするIII族窒化物半導体自立基板またはIII族窒化物半導体素子の製造方法。 - 前記クロム窒化物層表面の窒化クロム微結晶のうち、略三角錐形状を有する窒化クロム微結晶の占める面積比率が、70%以上である請求項6に記載のIII族窒化物半導体自立基板またはIII族窒化物半導体素子の製造方法。
- 前記クロム層は、複数の成長用下地基板上に、それぞれ平均成膜速度が1~10Å/秒の範囲となるよう間欠的に成膜される請求項6または7に記載のIII族窒化物半導体自立基板またはIII族窒化物半導体素子の製造方法。
- 前記略三角錐形状の窒化クロム微結晶の底辺の方位が、前記III族窒化物半導体層の<11−20>方向(a軸方向)群に平行である請求項7または8に記載のIII族窒化物半導体自立基板またはIII族窒化物半導体素子の製造方法。
- 前記成長用下地基板は、六方晶系または擬似六方晶系の結晶構造を有し、表面が(0001)面である請求項6~9のいずれか一項に記載のIII族窒化物半導体自立基板またはIII族窒化物半導体素子の製造方法。
- 基板と、該基板上のクロム窒化物層とを有するIII族窒化物成長用基板であって、
前記クロム窒化物層表面の窒化クロム微結晶のうち、略三角錐形状を有する窒化クロム微結晶の占める面積比率が、70%以上であることを特徴とするIII族窒化物成長用基板。
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US20140120637A1 (en) * | 2012-10-26 | 2014-05-01 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | Process for Growing at Least One Nanowire Using a Transition Metal Nitride Layer Obtained in Two Steps |
US9679966B2 (en) | 2012-10-26 | 2017-06-13 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | Electronic device containing nanowire(s), equipped with a transition metal buffer layer, process for growing at least one nanowire, and process for manufacturing a device |
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KR102187487B1 (ko) | 2014-04-03 | 2020-12-08 | 엘지이노텍 주식회사 | 발광소자 및 이를 구비한 조명 장치 |
US10882793B2 (en) * | 2015-11-11 | 2021-01-05 | Amotech Co., Ltd. | Ferrite sheet production method and ferrite sheet using same |
JP6266742B1 (ja) * | 2016-12-20 | 2018-01-24 | 古河機械金属株式会社 | Iii族窒化物半導体基板、及び、iii族窒化物半導体基板の製造方法 |
CN112470260B (zh) * | 2018-05-23 | 2024-05-14 | 胜高股份有限公司 | Iii族氮化物半导体基板及其制造方法 |
TWI825187B (zh) * | 2018-10-09 | 2023-12-11 | 日商東京威力科創股份有限公司 | 氮化物半導體膜之形成方法 |
CN113841223B (zh) * | 2019-05-23 | 2024-02-06 | 三菱电机株式会社 | 半导体基板的制造方法和半导体装置的制造方法 |
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JP2008088026A (ja) * | 2006-10-03 | 2008-04-17 | Tohoku Techno Arch Co Ltd | 構造体 |
JP2008110912A (ja) * | 2006-10-03 | 2008-05-15 | Tohoku Techno Arch Co Ltd | 基板の製造方法 |
JP2009054888A (ja) * | 2007-08-28 | 2009-03-12 | Tohoku Techno Arch Co Ltd | Iii族窒化物半導体とその製造方法 |
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US6218207B1 (en) * | 1998-05-29 | 2001-04-17 | Mitsushita Electronics Corporation | Method for growing nitride semiconductor crystals, nitride semiconductor device, and method for fabricating the same |
JP3631724B2 (ja) * | 2001-03-27 | 2005-03-23 | 日本電気株式会社 | Iii族窒化物半導体基板およびその製造方法 |
JP4117156B2 (ja) * | 2002-07-02 | 2008-07-16 | 日本電気株式会社 | Iii族窒化物半導体基板の製造方法 |
EP2197049B1 (en) * | 2005-04-04 | 2011-08-03 | Tohoku Techno Arch Co., Ltd. | Process for producing a GaN-based element |
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JP2008088026A (ja) * | 2006-10-03 | 2008-04-17 | Tohoku Techno Arch Co Ltd | 構造体 |
JP2008110912A (ja) * | 2006-10-03 | 2008-05-15 | Tohoku Techno Arch Co Ltd | 基板の製造方法 |
JP2009054888A (ja) * | 2007-08-28 | 2009-03-12 | Tohoku Techno Arch Co Ltd | Iii族窒化物半導体とその製造方法 |
Cited By (5)
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---|---|---|---|---|
US20140120637A1 (en) * | 2012-10-26 | 2014-05-01 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | Process for Growing at Least One Nanowire Using a Transition Metal Nitride Layer Obtained in Two Steps |
US9679966B2 (en) | 2012-10-26 | 2017-06-13 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | Electronic device containing nanowire(s), equipped with a transition metal buffer layer, process for growing at least one nanowire, and process for manufacturing a device |
US9698011B2 (en) * | 2012-10-26 | 2017-07-04 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | Process for growing at least one nanowire using a transition metal nitride layer obtained in two steps |
US9991342B2 (en) | 2012-10-26 | 2018-06-05 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | Electronic device containing nanowire(s), equipped with a transition metal buffer layer, process for growing at least one nanowire, and process for manufacturing a device |
US10636653B2 (en) | 2012-10-26 | 2020-04-28 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | Process for growing at least one nanowire using a transition metal nitride layer obtained in two steps |
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KR20130113452A (ko) | 2013-10-15 |
JP2012077345A (ja) | 2012-04-19 |
JP5665463B2 (ja) | 2015-02-04 |
WO2012043885A9 (ja) | 2013-07-18 |
CN103348043A (zh) | 2013-10-09 |
CN105529248B (zh) | 2018-04-06 |
CN103348043B (zh) | 2016-03-09 |
CN105529248A (zh) | 2016-04-27 |
KR101503618B1 (ko) | 2015-03-18 |
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