WO2017145802A1 - 多結晶窒化ガリウム自立基板及びそれを用いた発光素子 - Google Patents
多結晶窒化ガリウム自立基板及びそれを用いた発光素子 Download PDFInfo
- Publication number
- WO2017145802A1 WO2017145802A1 PCT/JP2017/004891 JP2017004891W WO2017145802A1 WO 2017145802 A1 WO2017145802 A1 WO 2017145802A1 JP 2017004891 W JP2017004891 W JP 2017004891W WO 2017145802 A1 WO2017145802 A1 WO 2017145802A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- gallium nitride
- polycrystalline
- single crystal
- standing substrate
- layer
- Prior art date
Links
- JMASRVWKEDWRBT-UHFFFAOYSA-N Gallium nitride Chemical compound [Ga]#N JMASRVWKEDWRBT-UHFFFAOYSA-N 0.000 title claims abstract description 375
- 229910002601 GaN Inorganic materials 0.000 title claims abstract description 372
- 239000000758 substrate Substances 0.000 title claims abstract description 308
- 239000013078 crystal Substances 0.000 claims abstract description 296
- 239000002245 particle Substances 0.000 claims abstract description 164
- 238000000034 method Methods 0.000 claims abstract description 61
- 238000001887 electron backscatter diffraction Methods 0.000 claims abstract description 4
- 239000010410 layer Substances 0.000 claims description 244
- 239000002346 layers by function Substances 0.000 claims description 50
- 239000002019 doping agent Substances 0.000 claims description 27
- 239000004065 semiconductor Substances 0.000 claims description 18
- 238000013507 mapping Methods 0.000 claims description 12
- 230000002441 reversible effect Effects 0.000 claims description 12
- 238000009826 distribution Methods 0.000 claims description 5
- 238000006243 chemical reaction Methods 0.000 abstract description 6
- 239000000843 powder Substances 0.000 description 74
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical compound [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 66
- 239000002994 raw material Substances 0.000 description 58
- 239000000463 material Substances 0.000 description 37
- 238000004519 manufacturing process Methods 0.000 description 36
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 26
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 22
- IUVCFHHAEHNCFT-INIZCTEOSA-N 2-[(1s)-1-[4-amino-3-(3-fluoro-4-propan-2-yloxyphenyl)pyrazolo[3,4-d]pyrimidin-1-yl]ethyl]-6-fluoro-3-(3-fluorophenyl)chromen-4-one Chemical compound C1=C(F)C(OC(C)C)=CC=C1C(C1=C(N)N=CN=C11)=NN1[C@@H](C)C1=C(C=2C=C(F)C=CC=2)C(=O)C2=CC(F)=CC=C2O1 IUVCFHHAEHNCFT-INIZCTEOSA-N 0.000 description 16
- 238000010304 firing Methods 0.000 description 14
- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 description 13
- 239000000126 substance Substances 0.000 description 13
- 238000002488 metal-organic chemical vapour deposition Methods 0.000 description 11
- 229910052757 nitrogen Inorganic materials 0.000 description 11
- 238000012545 processing Methods 0.000 description 11
- 239000011734 sodium Substances 0.000 description 11
- 239000011787 zinc oxide Substances 0.000 description 11
- 238000007716 flux method Methods 0.000 description 10
- 239000000203 mixture Substances 0.000 description 10
- 239000002002 slurry Substances 0.000 description 10
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 9
- 230000015572 biosynthetic process Effects 0.000 description 9
- 239000011777 magnesium Substances 0.000 description 9
- 238000005259 measurement Methods 0.000 description 9
- 239000006061 abrasive grain Substances 0.000 description 8
- 239000012298 atmosphere Substances 0.000 description 8
- 239000011575 calcium Substances 0.000 description 8
- 239000000470 constituent Substances 0.000 description 8
- 239000002612 dispersion medium Substances 0.000 description 8
- 238000010894 electron beam technology Methods 0.000 description 8
- 229910052594 sapphire Inorganic materials 0.000 description 8
- 239000010980 sapphire Substances 0.000 description 8
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 7
- 239000012299 nitrogen atmosphere Substances 0.000 description 7
- 230000008569 process Effects 0.000 description 7
- 229920002799 BoPET Polymers 0.000 description 6
- GYHNNYVSQQEPJS-UHFFFAOYSA-N Gallium Chemical compound [Ga] GYHNNYVSQQEPJS-UHFFFAOYSA-N 0.000 description 6
- BJQHLKABXJIVAM-UHFFFAOYSA-N bis(2-ethylhexyl) phthalate Chemical compound CCCCC(CC)COC(=O)C1=CC=CC=C1C(=O)OCC(CC)CCCC BJQHLKABXJIVAM-UHFFFAOYSA-N 0.000 description 6
- 238000000605 extraction Methods 0.000 description 6
- 229910052733 gallium Inorganic materials 0.000 description 6
- 229910002804 graphite Inorganic materials 0.000 description 6
- 239000010439 graphite Substances 0.000 description 6
- 238000000227 grinding Methods 0.000 description 6
- 239000001257 hydrogen Substances 0.000 description 6
- 229910052739 hydrogen Inorganic materials 0.000 description 6
- 229910052749 magnesium Inorganic materials 0.000 description 6
- 238000000465 moulding Methods 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 5
- 239000000654 additive Substances 0.000 description 5
- 230000000996 additive effect Effects 0.000 description 5
- 230000007547 defect Effects 0.000 description 5
- 239000002270 dispersing agent Substances 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 5
- 238000002248 hydride vapour-phase epitaxy Methods 0.000 description 5
- 239000004014 plasticizer Substances 0.000 description 5
- 229910052710 silicon Inorganic materials 0.000 description 5
- YIWUKEYIRIRTPP-UHFFFAOYSA-N 2-ethylhexan-1-ol Chemical compound CCCCC(CC)CO YIWUKEYIRIRTPP-UHFFFAOYSA-N 0.000 description 4
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 4
- 229910052782 aluminium Inorganic materials 0.000 description 4
- 239000011230 binding agent Substances 0.000 description 4
- 239000000919 ceramic Substances 0.000 description 4
- 229910003460 diamond Inorganic materials 0.000 description 4
- 239000010432 diamond Substances 0.000 description 4
- 238000011156 evaluation Methods 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 239000010440 gypsum Substances 0.000 description 4
- 229910052602 gypsum Inorganic materials 0.000 description 4
- 239000010703 silicon Substances 0.000 description 4
- 239000007921 spray Substances 0.000 description 4
- PIGFYZPCRLYGLF-UHFFFAOYSA-N Aluminum nitride Chemical compound [Al]#N PIGFYZPCRLYGLF-UHFFFAOYSA-N 0.000 description 3
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 3
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 3
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 3
- PRXRUNOAOLTIEF-ADSICKODSA-N Sorbitan trioleate Chemical compound CCCCCCCC\C=C/CCCCCCCC(=O)OC[C@@H](OC(=O)CCCCCCC\C=C/CCCCCCCC)[C@H]1OC[C@H](O)[C@H]1OC(=O)CCCCCCC\C=C/CCCCCCCC PRXRUNOAOLTIEF-ADSICKODSA-N 0.000 description 3
- 239000004147 Sorbitan trioleate Substances 0.000 description 3
- JNDMLEXHDPKVFC-UHFFFAOYSA-N aluminum;oxygen(2-);yttrium(3+) Chemical compound [O-2].[O-2].[O-2].[Al+3].[Y+3] JNDMLEXHDPKVFC-UHFFFAOYSA-N 0.000 description 3
- 229910052791 calcium Inorganic materials 0.000 description 3
- 238000005266 casting Methods 0.000 description 3
- 239000000460 chlorine Substances 0.000 description 3
- 238000007606 doctor blade method Methods 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 230000004907 flux Effects 0.000 description 3
- 229910052732 germanium Inorganic materials 0.000 description 3
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 238000010030 laminating Methods 0.000 description 3
- 239000007791 liquid phase Substances 0.000 description 3
- 239000000395 magnesium oxide Substances 0.000 description 3
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 3
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 3
- 239000000155 melt Substances 0.000 description 3
- 238000000206 photolithography Methods 0.000 description 3
- 229920002037 poly(vinyl butyral) polymer Polymers 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 238000005245 sintering Methods 0.000 description 3
- 229960000391 sorbitan trioleate Drugs 0.000 description 3
- 235000019337 sorbitan trioleate Nutrition 0.000 description 3
- 229910052712 strontium Inorganic materials 0.000 description 3
- 238000001771 vacuum deposition Methods 0.000 description 3
- 239000012808 vapor phase Substances 0.000 description 3
- 229910019901 yttrium aluminum garnet Inorganic materials 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 2
- -1 InN Chemical compound 0.000 description 2
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 2
- 238000002441 X-ray diffraction Methods 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 125000004429 atom Chemical group 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 230000004888 barrier function Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 229910052790 beryllium Inorganic materials 0.000 description 2
- ATBAMAFKBVZNFJ-UHFFFAOYSA-N beryllium atom Chemical compound [Be] ATBAMAFKBVZNFJ-UHFFFAOYSA-N 0.000 description 2
- 229910052793 cadmium Inorganic materials 0.000 description 2
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 description 2
- 238000001354 calcination Methods 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000003486 chemical etching Methods 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000005238 degreasing Methods 0.000 description 2
- 238000000280 densification Methods 0.000 description 2
- 238000000151 deposition Methods 0.000 description 2
- 238000003618 dip coating Methods 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 229910052738 indium Inorganic materials 0.000 description 2
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 239000011812 mixed powder Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 238000001451 molecular beam epitaxy Methods 0.000 description 2
- 150000004767 nitrides Chemical class 0.000 description 2
- 125000002524 organometallic group Chemical group 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 238000007639 printing Methods 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000010008 shearing Methods 0.000 description 2
- 229910052708 sodium Inorganic materials 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 238000004528 spin coating Methods 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 238000004544 sputter deposition Methods 0.000 description 2
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 description 2
- JBQYATWDVHIOAR-UHFFFAOYSA-N tellanylidenegermanium Chemical compound [Te]=[Ge] JBQYATWDVHIOAR-UHFFFAOYSA-N 0.000 description 2
- 238000002834 transmittance Methods 0.000 description 2
- XQQWBPOEMYKKBY-UHFFFAOYSA-H trimagnesium;dicarbonate;dihydroxide Chemical compound [OH-].[OH-].[Mg+2].[Mg+2].[Mg+2].[O-]C([O-])=O.[O-]C([O-])=O XQQWBPOEMYKKBY-UHFFFAOYSA-H 0.000 description 2
- 238000001947 vapour-phase growth Methods 0.000 description 2
- 235000012431 wafers Nutrition 0.000 description 2
- RUDFQVOCFDJEEF-UHFFFAOYSA-N yttrium(III) oxide Inorganic materials [O-2].[O-2].[O-2].[Y+3].[Y+3] RUDFQVOCFDJEEF-UHFFFAOYSA-N 0.000 description 2
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 description 1
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- WKBOTKDWSSQWDR-UHFFFAOYSA-N Bromine atom Chemical compound [Br] WKBOTKDWSSQWDR-UHFFFAOYSA-N 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910052693 Europium Inorganic materials 0.000 description 1
- PXGOKWXKJXAPGV-UHFFFAOYSA-N Fluorine Chemical compound FF PXGOKWXKJXAPGV-UHFFFAOYSA-N 0.000 description 1
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 1
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 1
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 238000001994 activation Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 229910052785 arsenic Inorganic materials 0.000 description 1
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 1
- 238000000889 atomisation Methods 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- GDTBXPJZTBHREO-UHFFFAOYSA-N bromine Substances BrBr GDTBXPJZTBHREO-UHFFFAOYSA-N 0.000 description 1
- 229910052794 bromium Inorganic materials 0.000 description 1
- 239000002775 capsule Substances 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 229910052593 corundum Inorganic materials 0.000 description 1
- 239000002178 crystalline material Substances 0.000 description 1
- 238000013480 data collection Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000010339 dilation Effects 0.000 description 1
- PZPGRFITIJYNEJ-UHFFFAOYSA-N disilane Chemical compound [SiH3][SiH3] PZPGRFITIJYNEJ-UHFFFAOYSA-N 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 238000004299 exfoliation Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 150000004678 hydrides Chemical class 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 238000001027 hydrothermal synthesis Methods 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 229910052740 iodine Inorganic materials 0.000 description 1
- 239000011630 iodine Substances 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 229910001425 magnesium ion Inorganic materials 0.000 description 1
- QBJCZLXULXFYCK-UHFFFAOYSA-N magnesium;cyclopenta-1,3-diene Chemical compound [Mg+2].C1C=CC=[C-]1.C1C=CC=[C-]1 QBJCZLXULXFYCK-UHFFFAOYSA-N 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000001000 micrograph Methods 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000000059 patterning Methods 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000003530 quantum well junction Substances 0.000 description 1
- 239000003870 refractory metal Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 229920002050 silicone resin Polymers 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 238000003980 solgel method Methods 0.000 description 1
- 239000011343 solid material Substances 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- 230000002269 spontaneous effect Effects 0.000 description 1
- 230000007480 spreading Effects 0.000 description 1
- 238000003892 spreading Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- IEXRMSFAVATTJX-UHFFFAOYSA-N tetrachlorogermane Chemical compound Cl[Ge](Cl)(Cl)Cl IEXRMSFAVATTJX-UHFFFAOYSA-N 0.000 description 1
- JLTRXTDYQLMHGR-UHFFFAOYSA-N trimethylaluminium Chemical compound C[Al](C)C JLTRXTDYQLMHGR-UHFFFAOYSA-N 0.000 description 1
- XCZXGTMEAKBVPV-UHFFFAOYSA-N trimethylgallium Chemical compound C[Ga](C)C XCZXGTMEAKBVPV-UHFFFAOYSA-N 0.000 description 1
- IBEFSUTVZWZJEL-UHFFFAOYSA-N trimethylindium Chemical compound C[In](C)C IBEFSUTVZWZJEL-UHFFFAOYSA-N 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
- 239000008096 xylene Substances 0.000 description 1
- 229910001845 yogo sapphire Inorganic materials 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
Images
Classifications
-
- 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
- H01L33/02—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
- H01L33/16—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 crystal structure or orientation, e.g. polycrystalline, amorphous or porous
- H01L33/18—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 crystal structure or orientation, e.g. polycrystalline, amorphous or porous within the light emitting region
-
- 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
- C30B19/00—Liquid-phase epitaxial-layer growth
- C30B19/02—Liquid-phase epitaxial-layer growth using molten solvents, e.g. flux
-
- 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
- C30B19/00—Liquid-phase epitaxial-layer growth
- C30B19/12—Liquid-phase epitaxial-layer growth characterised by the substrate
-
- 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
- C30B28/00—Production of homogeneous polycrystalline material with defined structure
- C30B28/04—Production of homogeneous polycrystalline material with defined structure from liquids
-
- 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
- C30B29/40—AIIIBV compounds wherein A is B, Al, Ga, In or Tl and B is N, P, As, Sb or Bi
- C30B29/403—AIII-nitrides
- C30B29/406—Gallium nitride
-
- 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
- C30B29/60—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape characterised by shape
- C30B29/605—Products containing multiple oriented crystallites, e.g. columnar crystallites
-
- 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
- C30B9/00—Single-crystal growth from melt solutions using molten solvents
- C30B9/04—Single-crystal growth from melt solutions using molten solvents by cooling of the solution
- C30B9/08—Single-crystal growth from melt solutions using molten solvents by cooling of the solution using other solvents
- C30B9/12—Salt solvents, e.g. flux growth
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/0248—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies
- H01L31/036—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes
- H01L31/0392—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate
-
- 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
- H01L33/02—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
-
- 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
- H01L33/36—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 electrodes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
Definitions
- the present invention relates to a polycrystalline gallium nitride free-standing substrate and a light-emitting element using the same.
- GaN gallium nitride
- MQW multi-quantum well layer
- a gallium nitride crystal multilayer substrate including a sapphire base substrate and a gallium nitride crystal layer formed by crystal growth on the substrate. Yes.
- GaN gallium nitride
- Patent Document 2 Japanese Patent Application Laid-Open No. 2010-1325566 discloses a self-supporting n-type gallium nitride single crystal substrate having a thickness of 200 ⁇ m or more.
- Patent Document 3 discloses a polycrystalline gallium nitride free-standing substrate composed of a plurality of gallium nitride-based single crystal particles oriented in a specific crystal orientation in a substantially normal direction.
- the crystal orientation of each gallium nitride single crystal particle measured by reverse pole figure mapping of electron beam backscatter diffraction (EBSD) on the substrate surface is distributed at various angles from the specific crystal orientation, and the average It is described that the inclination angle is 1 to 10 °.
- the inventors of the present invention incline the orientation orientation of the constituent particles at an average inclination angle of 0.1 ° or more and less than 1 °.
- the cross-sectional average diameter DT on the outermost surface of the gallium nitride single crystal particles exposed on the upper surface is set to 10 ⁇ m or more, a device such as a light emitting element or a solar cell is manufactured using the average diameter DT.
- the inventors have obtained knowledge that excellent characteristics such as high luminous efficiency and high conversion efficiency can be obtained.
- the knowledge that high luminous efficiency was obtained by comprising a light emitting element using such a polycrystalline gallium nitride freestanding substrate was also obtained.
- an object of the present invention is to provide a polycrystalline gallium nitride free-standing substrate that can provide excellent characteristics such as high light emission efficiency and high conversion efficiency when a device such as a light emitting element or a solar cell is produced using the same.
- Another object of the present invention is to provide a light emitting device that can obtain high luminous efficiency by using a polycrystalline gallium nitride free-standing substrate.
- a polycrystalline gallium nitride free-standing substrate composed of a plurality of gallium nitride-based single crystal particles oriented in a specific crystal orientation in a substantially normal direction, the polycrystalline gallium nitride free-standing substrate comprising: The crystal orientation of each gallium nitride-based single crystal particle measured by reverse pole figure mapping of electron beam backscatter diffraction (EBSD) on the top surface is inclined and distributed at various angles from the specific crystal orientation.
- EBSD electron beam backscatter diffraction
- a gallium nitride free-standing substrate is provided.
- a polycrystalline gallium nitride freestanding substrate according to the above aspect of the invention, A light emitting functional layer formed on the substrate and having at least one layer composed of a plurality of semiconductor single crystal particles having a single crystal structure in a substantially normal direction; A light-emitting element is provided.
- the gallium nitride substrate of the present invention can have the form of a freestanding substrate.
- the “self-supporting substrate” means a substrate that can be handled as a solid material without being deformed or damaged by its own weight when handled.
- the polycrystalline gallium nitride free-standing substrate of the present invention can be used as a substrate for various semiconductor devices such as light-emitting elements, but in addition to this, an electrode (which can be a p-type electrode or an n-type electrode), a p-type layer, n It can be used as a member or layer other than a substrate such as a mold layer.
- the advantages of the present invention may be described by taking a light emitting element which is one of the main applications as an example. However, similar or similar advantages are not limited to the technical consistency. The same applies to semiconductor devices.
- the polycrystalline gallium nitride free-standing substrate of the present invention is composed of a plurality of gallium nitride single crystal particles oriented in a specific crystal orientation in a substantially normal direction.
- the polycrystalline gallium nitride free-standing substrate has a top surface and a bottom surface, and the crystal orientation of each gallium nitride single crystal particle measured by reverse pole figure mapping of electron beam backscatter diffraction (EBSD) on the top surface is a specific crystal orientation (for example, (inclination of c-axis, a-axis, etc.) are distributed at various angles, and the average inclination angle is 0.1 ° or more and less than 1 °.
- EBSD electron beam backscatter diffraction
- the cross-sectional average diameter DT at the outermost surface of the gallium nitride single crystal particles exposed on the upper surface is 10 ⁇ m or more.
- EBSD is a well-known example in which when a crystalline material is irradiated with an electron beam, a Kikuchi line diffraction pattern, that is, an EBSD pattern, is observed by electron backscatter diffraction generated on the upper surface of the sample, and information on the crystal system and crystal orientation of the sample is obtained. It is a technique, and in combination with a scanning electron microscope (SEM), information on the crystal system of a micro region and the distribution of crystal orientation can be obtained by measuring and analyzing an EBSD pattern while scanning an electron beam.
- SEM scanning electron microscope
- the orientation orientation of the constituent particles is inclined at an average inclination angle of 0.1 ° or more and less than 1 °.
- a plurality of gallium nitride-based single crystal particles constituting a polycrystalline gallium nitride free-standing substrate are oriented in a specific crystal orientation in a substantially normal direction.
- the specific crystal orientation may be any crystal orientation (for example, c-plane, a-plane, etc.) that gallium nitride may have.
- each constituent particle on the upper surface of the substrate has its c-axis oriented in a substantially normal direction (that is, the c-plane is on the upper surface of the substrate). Will be placed).
- the plurality of gallium nitride single crystal particles constituting the polycrystalline gallium nitride free-standing substrate are oriented in a specific crystal orientation in a substantially normal direction, but the individual constituent particles are slightly inclined at various angles. That is, the upper surface of the substrate as a whole exhibits an orientation in a predetermined specific crystal orientation in a substantially normal direction, but the crystal orientation of each gallium nitride-based single crystal particle is distributed at various angles from the specific crystal orientation. .
- this unique orientation state can be evaluated by reverse pole figure mapping (for example, see FIG. 2 of Patent Document 3) of EBSD on the upper surface (plate surface) of the substrate.
- the crystal orientation of each gallium nitride-based single crystal particle measured by reverse pole figure mapping of EBSD on the upper surface of the substrate is distributed at various angles from the specific crystal orientation, and the average value of the tilt angles (average tilt) The angle) is from 0.1 ° to less than 1 °, preferably from 0.1 ° to 0.9 °, more preferably from 0.4 ° to 0.8 °.
- the polycrystalline gallium nitride free-standing substrate preferably has a single crystal structure in a substantially normal direction.
- the polycrystalline gallium nitride free-standing substrate is composed of a plate composed of a plurality of gallium nitride-based single crystal particles having a single crystal structure in a substantially normal direction. That is, the polycrystalline gallium nitride free-standing substrate is composed of a plurality of semiconductor single crystal particles that are two-dimensionally connected in the horizontal plane direction, and therefore can have a single crystal structure in a substantially normal direction. Therefore, the polycrystalline gallium nitride free-standing substrate is not a single crystal as a whole, but has a single crystal structure in local domain units.
- gallium nitride imparted with conductivity by introducing a p-type or n-type dopant as a substrate, a light-emitting element having a vertical structure can be realized, whereby luminance can be increased.
- a large-area surface light-emitting element used for surface-emitting illumination or the like can be realized at low cost.
- the plurality of gallium nitride-based single crystal particles constituting the free-standing substrate have a single crystal structure in a substantially normal direction.
- High-resistance grain boundaries do not exist in the pass, and as a result, preferable luminous efficiency is expected.
- the polycrystalline gallium nitride free-standing substrate of this embodiment can be preferably used for a vertical LED structure.
- it since there is no grain boundary in the current path, it can be applied not only to such a light emitting device but also to a power device, a solar cell, and the like.
- the plurality of gallium nitride single crystal particles constituting the self-supporting substrate have crystal orientations substantially aligned in a substantially normal direction.
- Crystal orientation that is generally aligned in the normal direction is not necessarily a crystal orientation that is perfectly aligned in the normal direction, as long as a device such as a light-emitting element using a self-supporting substrate can ensure desired device characteristics. This means that the crystal orientation may be aligned to some extent in the normal or similar direction.
- the gallium nitride single crystal particles have a structure that grows almost following the crystal orientation of the oriented polycrystalline sintered body used as the base material during the production of the polycrystalline gallium nitride free-standing substrate. It can be said that it has.
- the “structure grown substantially following the crystal orientation of the oriented polycrystalline sintered body” means a structure brought about by crystal growth affected by the crystal orientation of the oriented polycrystalline sintered body, and is not necessarily oriented.
- the crystal of the oriented polycrystalline sintered body is not necessarily a structure that has grown completely following the crystal orientation of the crystalline sintered body, as long as a device such as a light-emitting element using a self-supporting substrate can ensure the desired device characteristics.
- this structure includes a structure that grows in a different crystal orientation from the oriented polycrystalline sintered body.
- the expression “a structure grown substantially following the crystal orientation” can also be rephrased as “a structure grown substantially derived from the crystal orientation”. This paraphrase and the above meaning are similar to those in this specification. The same applies to expression. Therefore, although such crystal growth is preferably by epitaxial growth, it is not limited to this, and various forms of crystal growth similar thereto may be used. In any case, by growing in this way, the polycrystalline gallium nitride free-standing substrate can have a structure in which the crystal orientation is substantially uniform with respect to the substantially normal direction.
- the gallium nitride single layer constituting the self-supporting substrate is measured even when the reverse pole figure mapping of electron beam backscattering diffraction (EBSD) of the cross section orthogonal to the substrate upper surface (plate surface) of the polycrystalline gallium nitride free-standing substrate is measured. It can be confirmed that the crystal orientation of the crystal grains is oriented in a specific crystal orientation in a substantially normal direction. However, there is no orientation in the plate surface direction orthogonal to the substrate normal direction.
- EBSD electron beam backscattering diffraction
- the gallium nitride single crystal particles have a structure in which the crystal orientation is oriented only in a substantially normal direction, and the twist (rotation of crystal axis) distribution of the gallium nitride single crystal particles about the normal direction is random. is there.
- a device such as a light emitting function or a solar cell is manufactured using a polycrystalline gallium nitride free-standing substrate. The reason for this is not clear, but is considered to be an effect of light extraction efficiency.
- the polycrystalline gallium nitride free-standing substrate according to the above aspect is a single-crystal gallium nitride-based single crystal that is observed as a single crystal when viewed in the normal direction and has a grain boundary when viewed in a cut surface in the horizontal direction. It can also be regarded as an aggregate of crystal grains.
- the “columnar structure” does not mean only a typical vertically long column shape, but includes various shapes such as a horizontally long shape, a trapezoidal shape, and a shape in which the trapezoid is inverted. Defined as meaning.
- the polycrystalline gallium nitride free-standing substrate may have a structure having a crystal orientation that is aligned to some extent in the normal or similar direction, and does not necessarily have a columnar structure in a strict sense.
- the cause of the columnar structure is considered to be because the gallium nitride single crystal particles grow under the influence of the crystal orientation of the oriented polycrystalline sintered body used for the production of the polycrystalline gallium nitride free-standing substrate as described above.
- the average particle diameter of the cross section of the gallium nitride single crystal particles which can be said to be a columnar structure (hereinafter referred to as the average diameter of the cross section) depends not only on the film forming conditions but also on the average particle diameter of the plate surface of the oriented polycrystalline sintered body. It is thought to do.
- the average diameter of the cross section depends not only on the film forming conditions but also on the average particle diameter of the plate surface of the oriented polycrystalline sintered body. It is thought to do.
- the average diameter of the cross section of the gallium nitride free-standing substrate is used as part of the light emitting functional layer of a light emitting element, the light transmittance in the cross-sectional direction is poor due to the presence of grain boundaries, and light is scattered or reflected. For this reason, in the case of a light-emitting element having a structure in which light is extracted in the normal direction, an effect of increasing luminance due to scattered light from the grain boundary is also expected.
- the free-standing substrate top surface on which the light emitting functional layer is formed and the free-standing substrate bottom surface on which the electrode is formed It is preferable that they communicate with each other without passing through grain boundaries. That is, it is preferable that the gallium nitride single crystal particles exposed on the top surface of the polycrystalline gallium nitride free-standing substrate communicate with the bottom surface of the polycrystalline gallium nitride free-standing substrate without passing through the grain boundary. If there is a grain boundary, resistance is caused during energization, which causes a decrease in luminous efficiency.
- the cross-sectional average diameter DT at the outermost surface of the gallium nitride single crystal particles exposed on the upper surface of the polycrystalline gallium nitride free-standing substrate is equal to the gallium nitride single crystal exposed on the bottom surface of the polycrystalline gallium nitride free-standing substrate. it is preferably different from the cross-sectional average diameter D B at the outermost surface of the particles. By doing so, the crystallinity of the free-standing substrate and its constituent particles is improved. For example, when a gallium nitride crystal is grown using epitaxial growth via a gas phase or a liquid phase, the growth occurs not only in the normal direction but also in the horizontal direction, depending on the film forming conditions.
- the growth rates of the individual gallium nitride crystals are different, so that the fast growing particles cover the slow growing particles. May grow.
- the particles on the top surface side of the substrate are more likely to have a larger particle size than the bottom surface side of the substrate.
- the slow-growing crystal stops growing in the middle, and when observed in a certain section, grain boundaries can be observed in the normal direction.
- the particles exposed on the top surface of the substrate communicate with the bottom surface of the substrate without passing through the grain boundary, and there is no resistance phase in flowing current.
- the particles exposed on the top surface side of the substrate (the side opposite to the side in contact with the oriented polycrystalline sintered body that is the base substrate at the time of manufacture) Therefore, it is preferable to form a light emitting functional layer on the upper surface side of the substrate from the viewpoint of increasing the light emission efficiency of the LED having a vertical structure.
- the bottom side of the substrate (the side in contact with the oriented polycrystalline sintered body that is the base substrate at the time of manufacture) contains particles that do not communicate with the top side of the substrate. Efficiency may be reduced.
- the grain size increases with the growth.
- the front and bottom surfaces of the polycrystalline gallium nitride free-standing substrate have a smaller grain size of the gallium nitride crystal and are smaller on the upper surface side of the substrate. In other words, it can also be said to be the substrate bottom side. That is, in the polycrystalline gallium nitride free-standing substrate, it is preferable to form the light emitting functional layer on the side where the grain size of the gallium nitride crystal is large (the substrate upper surface side) from the viewpoint of increasing the light emission efficiency of the LED having a vertical structure.
- the upper surface side of the substrate (the side opposite to the side in contact with the oriented polycrystalline alumina sintered body that is the base substrate at the time of manufacture) is gallium.
- the substrate bottom surface side (the side in contact with the oriented polycrystalline alumina sintered body that is the base substrate at the time of manufacture) is the nitrogen surface. That is, the gallium surface of the polycrystalline gallium nitride free-standing substrate is dominated by particles communicating with the bottom surface without passing through the grain boundary. For this reason, it is preferable to produce a light emitting functional layer on the gallium surface side (substrate upper surface side) from the viewpoint of increasing the light emission efficiency of the LED having a vertical structure.
- the average cross-sectional diameter of the gallium nitride single crystal particles exposed on the upper surface of the substrate is It is preferable that the cross-sectional average diameter of the exposed gallium nitride single crystal particles is larger because the luminous efficiency increases (this is because the number of gallium nitride single crystal particles exposed on the upper surface of the substrate is smaller than the lower surface of the substrate). In other words, it is preferable that the number is smaller than the number of exposed gallium nitride single crystal particles).
- cross-sectional average diameter of the outermost surface of the polycrystalline nitride is exposed on the bottom surface of the gallium freestanding substrate gallium nitride based single crystal particles (hereinafter, referred to as cross-sectional average diameter D B of the bottom surface of the substrate), polycrystalline gallium nitride
- the ratio D T / D B of the cross-sectional average diameter (hereinafter referred to as the cross-sectional average diameter D T of the substrate upper surface) at the outermost surface of the gallium nitride single crystal particles exposed on the upper surface of the free-standing substrate is larger than 1.0.
- the ratio D T / D B is 1.5 or more, More preferably, it is 2.0 or more, Especially preferably, it is 3.0 or more, Most preferably, it is 5.0 or more.
- the ratio D T / D B is preferably 20 or less, and more preferably 10 or less.
- CAUSE luminous efficiency changes is not clear, but the grain boundary area is high the ratio D T / D B does not contribute to light emission by large grain size is decreased, or the crystal defects by large grain size This is considered to be reduced.
- the cause of the decrease in crystal defects is not clear, but it is also considered that particles containing defects grow slowly and particles with few defects grow at high speed.
- the crystallinity of the interface between the columnar structures constituting the polycrystalline gallium nitride free-standing substrate is lowered, when used as a light emitting functional layer of a light emitting element, the light emission efficiency is lowered, the light emission wavelength varies, and the light emission wavelength is broad. There is a possibility. For this reason, it is better that the cross-sectional average diameter of the columnar structure is larger.
- the cross-sectional average diameter DT on the outermost surface of the gallium nitride single crystal particles exposed on the upper surface of the polycrystalline gallium nitride free-standing substrate is 10 ⁇ m or more, preferably 20 ⁇ m or more, more preferably 50 ⁇ m or more, and particularly preferably Is 70 ⁇ m or more, and most preferably 100 ⁇ m or more.
- the upper limit of the average cross-sectional diameter of the gallium nitride-based single crystal particles on the outermost surface (upper surface) of the polycrystalline gallium nitride free-standing substrate is not particularly limited, but is practically 1000 ⁇ m or less, more practically 500 ⁇ m or less, Actually, it is 200 ⁇ m or less.
- the sintered grains on the plate surface of the particles constituting the oriented polycrystalline sintered body used for the production of a polycrystalline gallium nitride free-standing substrate are used.
- the diameter is desirably 10 ⁇ m or more, more desirably 10 ⁇ m to 1000 ⁇ m, still more desirably 10 ⁇ m to 800 ⁇ m, and particularly desirably 14 ⁇ m to 500 ⁇ m.
- the cross-sectional average diameter of the gallium nitride single crystal particles on the outermost surface (upper surface) of the polycrystalline gallium nitride free-standing substrate is larger than the cross-sectional average diameter of the bottom surface of the free-standing substrate, oriented polycrystal
- the sintered particle size on the plate surface of the particles constituting the sintered body is preferably 10 ⁇ m to 100 ⁇ m, more preferably 14 ⁇ m to 70 ⁇ m.
- the gallium nitride single crystal particles constituting the polycrystalline gallium nitride free-standing substrate may not contain a dopant.
- dopant means that an element added for the purpose of imparting some function or characteristic is not contained, and it is needless to say that inclusion of inevitable impurities is allowed.
- the gallium nitride-based single crystal particles constituting the polycrystalline gallium nitride free-standing substrate may be doped with an n-type dopant or a p-type dopant, and in this case, the polycrystalline gallium nitride free-standing substrate is replaced with a p-type electrode, n It can be used as a member or layer other than a substrate such as a mold electrode, p-type layer, and n-type layer.
- the p-type dopant include one or more selected from the group consisting of beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), zinc (Zn), and cadmium (Cd). It is done.
- the n-type dopant include one or more selected from the group consisting of silicon (Si), germanium (Ge), tin (Sn), and oxygen (O).
- the gallium nitride single crystal particles constituting the polycrystalline gallium nitride free-standing substrate may be mixed to control the band gap.
- the gallium nitride single crystal particles may be composed of gallium nitride mixed with at least one crystal selected from the group consisting of AlN and InN, and may be p-type gallium nitride and / or n.
- the mixed gallium nitride may be doped with a p-type dopant or an n-type dopant.
- Al x Ga 1-x N which is a mixed crystal of gallium nitride and AlN, is used as a p-type substrate by doping Mg
- Al x Ga 1-x N is used as an n-type substrate by doping Si. be able to.
- the band gap is widened by mixing gallium nitride with AlN, and the emission wavelength can be shifted to a higher energy side.
- gallium nitride may be mixed with InN, whereby the band gap is narrowed and the emission wavelength can be shifted to a lower energy side.
- the polycrystalline gallium nitride free-standing substrate preferably has a diameter of 50.8 mm (2 inches) or more, more preferably has a diameter of 100 mm (4 inches) or more, and more preferably has a diameter of 200 mm (8 inches) or more. .
- the polycrystalline gallium nitride free-standing substrate is preferably circular or substantially circular when viewed from above, but is not limited thereto.
- the area is preferably at 2026Mm 2 or more, more preferably 7850mm 2 or more, further preferably 31400Mm 2 or more.
- the area may be smaller than the above range, for example, a diameter of 50.8 mm (2 inches) or less, and 2026 mm 2 or less in terms of area.
- the thickness of the polycrystalline gallium nitride free-standing substrate needs to be able to impart self-supporting property to the substrate, and is preferably 20 ⁇ m or more, more preferably 100 ⁇ m or more, and further preferably 300 ⁇ m or more. An upper limit should not be defined for the thickness of the polycrystalline gallium nitride free-standing substrate, but 3000 ⁇ m or less is realistic from the viewpoint of manufacturing cost.
- the aspect ratio T / which is defined as the ratio of the thickness T of the polycrystalline gallium nitride free-standing substrate to the cross-sectional average diameter DT at the outermost surface of the gallium nitride-based single crystal particles exposed on the upper surface of the polycrystalline gallium nitride free-standing substrate DT is preferably 0.7 or more, more preferably 1.0 or more, and further preferably 3.0 or more.
- this aspect ratio is an LED, it is preferable from the viewpoint of increasing luminous efficiency.
- the reason why the luminous efficiency is increased may be that the defect density in the gallium nitride is lower in the high aspect ratio particles and the light extraction efficiency is increased, but the details are not clear.
- the light emitting functional layer is formed on the upper surface side of the self-supporting substrate (the side opposite to the side in contact with the oriented polycrystalline sintered body which is the base substrate at the time of manufacture).
- the ratio D T / D B of the cross-sectional average diameter D T of the top surface of the substrate to the average cross-sectional diameter D B of the bottom surface of the self-supporting substrate should take an appropriate value, and (3) constitute a self-supporting substrate good a larger cross-sectional average diameter of the substrate outermost surface of the particles, (4) the aspect ratio T / D T of the particles constituting the free-standing substrate is larger is better.
- the thickness of the polycrystalline gallium nitride free-standing substrate is preferably 20 ⁇ m or more, more preferably 100 ⁇ m or more, and further preferably 300 ⁇ m or more.
- the thickness of the gallium nitride crystal is increased, it is not preferable from the viewpoint of cost, and it is preferable that the gallium nitride crystal is thin as long as it is independent.
- the thickness of the polycrystalline gallium nitride free-standing substrate is practically 3000 ⁇ m or less, preferably 600 ⁇ m or less, and preferably 300 ⁇ m or less. Accordingly, the thickness that achieves both a self-supporting and high luminous efficiency viewpoint and a cost viewpoint is preferably about 50 to 500 ⁇ m, and more preferably about 300 to 500 ⁇ m.
- the manufacturing method of the polycrystalline gallium nitride free-standing substrate of the present invention is not particularly limited, but three preferred methods are exemplified below. Both methods are common in that a polycrystalline gallium nitride layer is formed on an oriented polycrystalline sintered body as a base substrate.
- the first preferred method is a method of growing a polycrystalline gallium nitride layer on an oriented polycrystalline sintered body having a small average tilt angle. That is, in this oriented polycrystalline sintered body, the crystal orientation of each single crystal particle measured by reverse pole figure mapping of electron beam backscattering diffraction (EBSD) on the upper surface is inclined at various angles from the specific crystal orientation. It is distributed and its average inclination angle is small.
- the growth method of the gallium nitride crystal is not particularly limited, and a liquid phase method such as a sodium flux method, a vapor phase method such as an HVPE method (hydride vapor phase growth method), or the like can be preferably used.
- Gallium nitride particles grow so as to generally follow the crystal orientation of the oriented polycrystalline sintered body.
- the tilt angle of the oriented gallium nitride crystal obtained is 0.1 ° or more by setting the tilt angle of the particles constituting the upper surface of the oriented polycrystalline sintered body to be the base to 0.1 ° or more and less than 1 °. It can be controlled to be less than 1 °. Therefore, an oriented polycrystalline sintered body is prepared as a base substrate for producing a polycrystalline gallium nitride free-standing substrate.
- the composition of the oriented polycrystalline sintered body is not particularly limited, but is preferably one selected from an oriented polycrystalline alumina sintered body, an oriented polycrystalline zinc oxide sintered body, and an oriented polycrystalline alumina nitride sintered body.
- An oriented polycrystalline alumina sintered body is particularly preferred.
- the second preferred method is a method of adding impurities into the flux when growing the polycrystalline gallium nitride layer by the Na flux method.
- the average inclination angle of the polycrystalline gallium nitride layer can be controlled within a range of 0.1 ° to less than 1 °. That is, even when grown by the Na flux method, the gallium nitride crystal grows so as to substantially follow the inclination angle of the oriented polycrystalline sintered body as a base.
- the gallium nitride crystal can be grown so as to reduce the tilt angle of the base substrate by adding impurities into the Na flux.
- the inclination angle of the gallium nitride crystal surface is reduced by 10% to 50% from the inclination angle of the upper surface of the base substrate. Since the amount of change in tilt angle when growing a gallium nitride crystal by the flux method varies depending on the type and concentration of the additive element, the tilt angle is 0.1 ° or more and 1 when combined with a base substrate having an appropriate tilt angle. It is possible to realize a gallium nitride crystal of less than 0 °.
- the mechanism for reducing the tilt angle is not clear, but is considered as follows. That is, the amount of change in tilt angle varies depending on the type of element added.
- the surface morphologies of the obtained gallium nitride crystals are different. From these facts, when a specific element is added, a crystal grain with a small tilt angle grows at a faster rate than a crystal grain with a large tilt angle, and finally, by incorporating a crystal grain with a small tilt angle, It is conceivable that the overall inclination angle becomes small.
- a third preferred method is a method of forming a seed crystal layer, or a buffer layer and a seed crystal layer on a base substrate by a vapor phase method, and then growing a polycrystalline gallium nitride layer.
- a seed crystal layer or a buffer layer is selectively formed only on the base substrate particles having a small inclination angle.
- a gallium nitride layer thickness 1 to 10 ⁇ m
- a gallium nitride crystal is formed only on alumina particles with a small inclination angle to be a seed crystal layer formed on an alumina substrate, and then a gallium nitride crystal is formed by a flux method, an HVPE method, or the like.
- the gallium nitride layer serving as the seed crystal layer is preferably formed by MOCVD.
- MOCVD MOCVD
- a buffer layer is formed only on alumina particles having a small inclination angle, and high temperature growth at 1000 to 1150 ° C. is performed on the buffer layer.
- the gallium nitride layer is preferably formed as a seed crystal layer.
- a high-temperature grown gallium nitride layer can hardly be grown on alumina without a buffer layer.
- a buffer layer there are (i) a case where an InGaN layer is used and (ii) a case where a low-temperature grown gallium nitride layer is formed.
- the above (i) uses the characteristic that InGaN layers are formed with different In compositions depending on the tilt angle, and gallium nitride with a low growth rate is formed on the particles with a large tilt angle without the incorporation of In. InGaN with a high growth rate is formed on the particles having a small inclination angle.
- the gallium nitride layer having a low growth rate is almost sublimated, and a high-temperature grown gallium nitride layer (seed crystal layer) is formed only on the InGaN layer.
- the above (ii) is based on the knowledge that a low-temperature gallium nitride layer on a particle having a large tilt angle is likely to sublime, and this is used to make a high-temperature gallium nitride layer (species only on a particle having a small tilt angle). Crystal layer) is formed.
- a high-temperature gallium nitride layer is grown as a seed crystal layer using at least one buffer layer of the above two types, and a polycrystalline gallium nitride layer is formed on the seed crystal layer by a flux method, an HVPE method, or the like.
- An oriented gallium nitride substrate with a small average tilt angle can be produced by growing a thick film and processing it into a substrate shape.
- the In composition is desirably set to 10 mol% to 20 mol%.
- the buffer layer is preferably formed in a nitrogen atmosphere at a temperature of 650 ° C. to 850 ° C.
- the thickness of the buffer layer is 1 nm to 15 nm.
- the thickness of the buffer layer is about 20 nm to 50 nm, whereas in (ii) above, a part of low-temperature grown gallium nitride on particles with a large tilt angle Therefore, it is necessary to control the thickness of the buffer layer thinly and precisely.
- the buffer layer is preferably formed in a hydrogen atmosphere at a temperature of 500 ° C. to 550 ° C.
- the polycrystalline gallium nitride free-standing substrate can be obtained by removing the oriented polycrystalline sinter from the oriented polycrystalline sinter formed with the polycrystalline gallium nitride layer.
- the method for removing the oriented polycrystalline sintered body is not particularly limited, but is spontaneous, utilizing grinding, chemical etching, interfacial heating (laser lift-off) by laser irradiation from the oriented sintered body side, and thermal expansion difference during temperature rise Exfoliation and the like.
- the oriented polycrystalline sintered body used as a base material for the production of the polycrystalline gallium nitride free-standing substrate of the present invention may be produced by any production method and is particularly limited. Not. For example, it may be produced based on the method described in Patent Document 3 (WO2015 / 151902A1).
- the method for producing an oriented polycrystalline sintered body is as follows.
- the fine raw material powder layer and the plate surface of the plate-like raw material particles are the fine raw material powder. It includes a step of producing a laminate in which plate-like raw material powder layers arranged along the surface of the layer are alternately laminated, and (b) a step of firing the laminate.
- the fine raw material powder layer used in step (a) is a layer of aggregates of fine raw material particles.
- the fine raw material powder is a powder having an average particle size smaller than that of the plate-like raw material powder.
- the fine raw material powder layer may be a layer obtained by molding the fine raw material powder itself, or may be a layer obtained by shaping the fine raw material powder added with an additive.
- the additive include a sintering aid, graphite, a binder, a plasticizer, a dispersant, and a dispersion medium.
- the molding method is not particularly limited, and examples thereof include tape molding, extrusion molding, casting molding, injection molding, and uniaxial press molding.
- the thickness of the fine raw material powder layer is preferably 5 to 100 ⁇ m, more preferably 10 to 100 ⁇ m, still more preferably 20 to 60 ⁇ m.
- the plate-like raw material powder layer used in the step (a) is a layer of aggregates of plate-like raw material particles.
- the plate-like raw material powder preferably has an aspect ratio of 3 or more.
- the aspect ratio is average particle size / average thickness.
- the average particle diameter is the average value of the major axis lengths of the particle plate surfaces
- the average thickness is the average value of the minor axis lengths of the particles.
- the average particle size of the plate-like raw material powder is preferably larger from the viewpoint of high orientation of the oriented sintered body, preferably 1.5 ⁇ m or more, more preferably 5 ⁇ m or more, still more preferably 10 ⁇ m or more, and particularly preferably 15 ⁇ m or more. preferable. However, the smaller one is preferable from the viewpoint of densification, and 30 ⁇ m or less is preferable. Therefore, the average particle size is preferably 1.5 ⁇ m to 30 ⁇ m in order to achieve both high orientation and densification.
- the plate-like raw material powder layer may be a layer of the plate-like raw material powder itself or a layer obtained by adding an additive to the plate-like raw material powder.
- the additive examples include a sintering aid, graphite, a binder, a plasticizer, a dispersant, and a dispersion medium.
- the plate-like raw material powder layer is arranged so that the plate surfaces of the plate-like raw material particles constituting the plate-like raw material powder are along the surface of the fine raw material powder layer.
- the plate-like raw material powder is preferably single particles. When the particles are not single particles, the degree of orientation and the tilt angle may be deteriorated.
- at least one of a classification process, a crushing process, and a water tank process may be employed, but it is preferable to employ all the processes.
- the classification process and the crushing process are preferably employed when there is aggregation or the like.
- Examples of the classification treatment include air classification.
- Examples of the crushing treatment include pot crushing and wet atomization.
- the varicella treatment is preferably employed when fine powder is mixed.
- the laminate produced in the step (a) is obtained by alternately laminating fine raw material powder layers and plate-like raw material powder layers.
- a laminated body a single-side processed body in which one side of a molded body of fine raw material powder is entirely or partially covered with a plate-like raw material powder layer is manufactured, and a laminated body is manufactured using the single-side processed body May be.
- a double-sided processed body in which both surfaces of a molded body of fine raw material powder are entirely or partially covered with a plate-like raw material powder layer is produced, and a laminate using the double-sided processed body and an unprocessed molded body May be produced.
- the single-sided processed body or the double-sided processed body may be produced by laminating a molded body of plate-shaped raw material powder having a thickness smaller than that of the molded body on one side or both sides of the molded body of fine raw material powder.
- the molded body of the plate-shaped raw material powder may be formed by applying a shearing force by tape molding or printing so that the plate surface of the plate-shaped raw material particles is along the surface of the molded body.
- the single-sided processed body or the double-sided processed body may be produced by printing, spray-coating, spin-coating, or dip-coating a dispersion of the plate-shaped raw material powder on one or both surfaces of the compact of the raw material powder.
- the plate surfaces of the plate-like raw material particles are arranged so as to be along the surface of the molded body without forcing a shearing force.
- the plate-like raw material particles arranged on the surface of the molded body may overlap several plate-like raw material particles, but preferably do not overlap other plate-like raw material particles.
- the single-sided processed body When using a single-sided processed body, the single-sided processed body may be stacked so that fine raw material powder layers and plate-shaped raw material powder layers are alternately stacked. When the double-sided processed body is used, the double-sided processed body and the green processed raw material powder compact may be alternately laminated.
- a laminated body may be produced using both a single-sided processed body and a double-sided processed body, or a laminated body may be produced using a single-sided processed body, a double-sided processed body, and an unprocessed molded body. Good.
- the laminate is fired.
- the firing method is not particularly limited, but pressure firing and hydrogen firing are preferable.
- pressure firing include hot press firing and HIP firing.
- a capsule method can also be used.
- Pressure when the hot-press firing is preferably 50 kgf / cm 2 or more, 200 kgf / cm 2 or more is more preferable.
- Pressure when the HIP sintering is preferably 1000 kgf / cm 2 or more, 2,000 kgf / cm 2 or more is more preferable.
- the firing atmosphere is not particularly limited, but any one of air, an inert gas such as nitrogen and Ar, and a vacuum atmosphere is preferable, nitrogen and Ar atmosphere are particularly preferable, and nitrogen atmosphere is most preferable.
- a fine raw material powder layer that is a layer of an aggregate of fine raw material particles and a plate-like raw material powder layer in which plate surfaces of the plate-like raw material particles are arranged along the surface of the fine raw material powder layer are alternately arranged. It is a laminated one. When the laminate is fired, the plate-like raw material particles become seed crystals (template), the fine raw material particles become a matrix, and the template grows homoepitaxially while taking in the matrix.
- the obtained sintered body is an oriented sintered body having a high degree of orientation and a small inclination angle.
- the degree of orientation and the inclination angle depend on the coverage with which the plate-like raw material powder covers the surface of the fine raw material powder layer. When the coverage is 1 to 60% (preferably 1 to 20%, more preferably 3 to 20%), the degree of orientation is high and the inclination angle is small. Further, the degree of orientation and the inclination angle depend on the thickness of the fine raw material powder layer. When the thickness of the fine raw material powder layer is 5 to 100 ⁇ m (preferably 10 to 100 ⁇ m, more preferably 20 to 60 ⁇ m), the degree of orientation is high and the inclination angle is small.
- the degree of orientation refers to the degree of c-plane orientation obtained by the Lotgering method using an X-ray diffraction profile, and the XRC half-value width (XRC ⁇ FWHM) is used as the inclination angle.
- the composition of the oriented polycrystalline sintered body is not particularly limited, but it is one type selected from an oriented polycrystalline alumina sintered body, an oriented polycrystalline zinc oxide sintered body, and an oriented polycrystalline aluminum nitride sintered body. preferable. Therefore, examples of the main component of the fine raw material powder and the plate-like raw material powder include alumina, ZnO, and AlN. Among these, alumina is preferable. When the main component is alumina, the firing temperature (maximum temperature reached) is preferably 1850 to 2050 ° C., more preferably 1900 to 2000 ° C.
- the “main component” refers to a component having a mass ratio of 50% (preferably 60%, more preferably 70%, still more preferably 80%) or more in the entire powder.
- the oriented sintered body obtained by the manufacturing method of this embodiment has a high c-plane orientation and a small tilt angle.
- a c-plane orientation degree of 80% or more preferably 90% or more, more preferably 96% or more
- XRC ⁇ FWHM measured using the X-ray rocking curve method is 5 ° or less (preferably 2.5 ° or less, more preferably 1.5 ° or less, and further preferably 1.0 °. The following) can be obtained.
- a high-quality light-emitting element can be manufactured using the above-described polycrystalline gallium nitride free-standing substrate according to the present invention. As described above, high luminous efficiency can be obtained by forming a light emitting element using the polycrystalline gallium nitride free-standing substrate according to the present invention.
- the structure of the light emitting element using the polycrystalline gallium nitride free-standing substrate of the present invention and the manufacturing method thereof are not particularly limited.
- the light-emitting element is manufactured by providing a light-emitting functional layer on a polycrystalline gallium nitride free-standing substrate, and the formation of the light-emitting functional layer has a crystal orientation that substantially follows the crystal orientation of the gallium nitride substrate. It is preferable to form one or more layers composed of a plurality of semiconductor single crystal particles having a single crystal structure in a substantially normal direction.
- a polycrystalline gallium nitride free-standing substrate is used as a member or layer other than a substrate such as an electrode (which can be a p-type electrode or an n-type electrode), a p-type layer, an n-type layer, etc. Good.
- the element size is not particularly limited, and may be a small element of 5 mm ⁇ 5 mm or less, or a surface light emitting element of 10 cm ⁇ 10 cm or more.
- FIG. 1 schematically shows a layer structure of a light-emitting element according to one embodiment of the present invention.
- a light-emitting element 10 shown in FIG. 1 includes a polycrystalline gallium nitride free-standing substrate 12 and a light-emitting functional layer 14 formed on the substrate.
- the light emitting functional layer 14 has one or more layers composed of a plurality of semiconductor single crystal particles having a single crystal structure in a substantially normal direction.
- the light-emitting functional layer 14 emits light based on the principle of a light-emitting element such as an LED by appropriately providing electrodes and applying a voltage.
- the polycrystalline gallium nitride free-standing substrate 12 of the present invention it can be expected to obtain a light-emitting element having a light emission efficiency equivalent to that when a gallium nitride single crystal substrate is used, and a significant cost reduction can be realized.
- gallium nitride imparted with conductivity by introducing a p-type or n-type dopant as a substrate, a light-emitting element having a vertical structure can be realized, whereby luminance can be increased.
- a large area surface light emitting device can be realized at low cost.
- a light emitting functional layer 14 is formed on the substrate 12.
- the light emitting functional layer 14 may be provided on the entire surface or a part of the substrate 12, or may be provided on the entire surface or a part of the buffer layer when a buffer layer described later is formed on the substrate 12. Good.
- the light-emitting functional layer 14 has one or more layers composed of a plurality of semiconductor single crystal particles having a single crystal structure in a substantially normal direction, and is appropriately provided with electrodes and / or phosphors to apply a voltage. Therefore, it is possible to adopt various known layer configurations that cause light emission based on the principle of a light emitting element typified by an LED. Therefore, the light emitting functional layer 14 may emit visible light such as blue and red, or may emit ultraviolet light without visible light or with visible light.
- the light emitting functional layer 14 preferably constitutes at least a part of a light emitting element using a pn junction, and the pn junction includes a p-type layer 14a and an n-type layer 14c as shown in FIG.
- the active layer 14b may be included in between.
- a double heterojunction or a single heterojunction (hereinafter collectively referred to as a heterojunction) using a layer having a smaller band gap than the p-type layer and / or the n-type layer as the active layer may be used.
- a quantum well structure in which the active layer is thin can be adopted as one form of the p-type layer-active layer-n-type layer.
- the light emitting functional layer 14 preferably includes a pn junction and / or a heterojunction and / or a quantum well junction having a light emitting function.
- At least one layer constituting the light emitting functional layer 14 is at least selected from the group consisting of an n-type layer doped with an n-type dopant, a p-type layer doped with a p-type dopant, and an active layer.
- an n-type layer, the p-type layer, and the active layer may be composed of the same material as the main component, or may be composed of materials whose main components are different from each other.
- each layer constituting the light emitting functional layer 14 is not particularly limited as long as it grows substantially following the crystal orientation of the polycrystalline gallium nitride free-standing substrate and has a light emitting function. It is preferably composed of a material mainly composed of at least one selected from a zinc (ZnO) -based material and an aluminum nitride (AlN) -based material, and appropriately includes a dopant for controlling p-type or n-type. It may be a thing.
- a particularly preferable material is a gallium nitride (GaN) -based material which is the same material as the polycrystalline gallium nitride free-standing substrate.
- the material constituting the light emitting functional layer 14 may be a mixed crystal in which, for example, AlN, InN or the like is dissolved in GaN in order to control the band gap.
- the light emitting functional layer 14 may be a heterojunction made of a plurality of types of materials. For example, a gallium nitride (GaN) -based material may be used for the p-type layer, and a zinc oxide (ZnO) -based material may be used for the n-type layer.
- GaN gallium nitride
- ZnO zinc oxide
- a zinc oxide (ZnO) -based material may be used for the p-type layer
- a gallium nitride (GaN) -based material may be used for the active layer and the n-type layer, and the combination of materials is not particularly limited.
- Each layer constituting the light emitting functional layer 14 is composed of a plurality of semiconductor single crystal particles having a single crystal structure in a substantially normal direction. That is, each layer is composed of a plurality of semiconductor single crystal particles that are two-dimensionally connected in the horizontal plane direction, and therefore has a single crystal structure in a substantially normal direction. Therefore, each layer of the light emitting functional layer 14 is not a single crystal as a whole, but has a single crystal structure in a local domain unit, and thus can have high crystallinity sufficient to ensure a light emitting function. .
- the semiconductor single crystal particles constituting each layer of the light emitting functional layer 14 have a structure grown substantially following the crystal orientation of the polycrystalline gallium nitride free-standing substrate which is the substrate 12.
- the structure grown roughly following the crystal orientation of the polycrystalline gallium nitride free-standing substrate means a structure brought about by crystal growth affected by the crystal orientation of the polycrystalline gallium nitride free-standing substrate. It is not necessarily a structure grown completely following the crystal orientation of the gallium nitride free-standing substrate, but as long as the desired light emitting function can be secured, it is a structure grown to some extent according to the crystal orientation of the polycrystalline gallium nitride free-standing substrate. Good. That is, this structure includes a structure that grows in a different crystal orientation from the oriented polycrystalline sintered body. In that sense, the expression “a structure grown substantially following the crystal orientation” can be rephrased as “a structure grown substantially derived from the crystal orientation”.
- crystal growth is preferably by epitaxial growth, it is not limited to this, and various forms of crystal growth similar thereto may be used.
- the normal line also extends from the polycrystalline gallium nitride free-standing substrate to each layer of the light emitting functional layer. With respect to the direction, the crystal orientation is almost uniform, and good light emission characteristics can be obtained. That is, when the light emitting functional layer 14 also grows substantially following the crystal orientation of the polycrystalline gallium nitride free-standing substrate 12, the orientation is substantially constant in the vertical direction of the substrate.
- the normal direction is the same as that of a single crystal, and when a polycrystalline gallium nitride free-standing substrate to which an n-type dopant is added is used, a light-emitting element having a vertical structure using the polycrystalline gallium nitride free-standing substrate as a cathode and when a polycrystalline gallium nitride free-standing substrate to which a p-type dopant is added is used, a light-emitting element having a vertical structure using the polycrystalline gallium nitride free-standing substrate as an anode can be obtained.
- each layer of the light-emitting functional layer 14 is a single crystal when viewed in the normal direction. It can also be regarded as an aggregate of columnar-structured semiconductor single crystal particles that are observed and viewed from a cut surface in the horizontal plane direction.
- the “columnar structure” does not mean only a typical vertically long column shape, but includes various shapes such as a horizontally long shape, a trapezoidal shape, and a shape in which the trapezoid is inverted. Defined as meaning.
- each layer has only to have a structure grown to some extent along the crystal orientation of the polycrystalline gallium nitride free-standing substrate, and does not necessarily have a columnar structure in a strict sense.
- the cause of the columnar structure is considered to be that the semiconductor single crystal particles grow under the influence of the crystal orientation of the polycrystalline gallium nitride free-standing substrate as the substrate 12 as described above.
- the average particle diameter of the cross section of the semiconductor single crystal particles which can be said to be a columnar structure (hereinafter referred to as the average cross section diameter) depends not only on the film forming conditions but also on the average particle diameter of the plate surface of the polycrystalline gallium nitride free-standing substrate. It is considered a thing.
- the interface of the columnar structure constituting the light emitting functional layer affects the light emission efficiency and the light emission wavelength, but due to the presence of the grain boundary, the light transmittance in the cross-sectional direction is poor, and the light is scattered or reflected. For this reason, in the case of a structure in which light is extracted in the normal direction, an effect of increasing the luminance due to scattered light from the grain boundary is also expected.
- the cross-sectional average diameter of the columnar structure is larger.
- the cross-sectional average diameter of the semiconductor single crystal particles on the outermost surface of the light emitting functional layer 14 is 10 ⁇ m or more, more preferably 15 ⁇ m or more, further preferably 20 ⁇ m or more, particularly preferably 50 ⁇ m or more, and most preferably 70 ⁇ m or more.
- the upper limit of the average cross-sectional diameter is not particularly limited, but is practically 1000 ⁇ m or less, more realistically 500 ⁇ m or less, and more realistically 200 ⁇ m or less.
- the average cross-sectional diameter of the gallium nitride-based single crystal particles constituting the polycrystalline gallium nitride free-standing substrate is 10 ⁇ m to 1000 ⁇ m at the outermost surface of the substrate. Is desirable, and more desirably 10 ⁇ m or more.
- a buffer layer for suppressing the reaction is provided between the polycrystalline gallium nitride free-standing substrate 12 and the light emitting functional layer 14. It may be provided.
- the main component of such a buffer layer is not particularly limited, but it is preferably composed of a material mainly containing at least one selected from a zinc oxide (ZnO) -based material and an aluminum nitride (AlN) -based material. , A dopant for controlling p-type to n-type may be included as appropriate.
- Each layer constituting the light emitting functional layer 14 is preferably made of a gallium nitride material.
- a gallium nitride material For example, an n-type gallium nitride layer and a p-type gallium nitride layer may be grown in order on the polycrystalline gallium nitride free-standing substrate 12, and the stacking order of the p-type gallium nitride layer and the n-type gallium nitride layer may be reversed.
- the p-type dopant used for the p-type gallium nitride layer include a group consisting of beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), zinc (Zn), and cadmium (Cd).
- n-type dopant used for the n-type gallium nitride layer at least one selected from the group consisting of silicon (Si), germanium (Ge), tin (Sn), and oxygen (O) is used.
- Si silicon
- Ge germanium
- Sn tin
- O oxygen
- the p-type gallium nitride layer and / or the n-type gallium nitride layer may be made of gallium nitride mixed with one or more kinds of crystals selected from the group consisting of AlN and InN.
- the mixed gallium nitride may be doped with a p-type dopant or an n-type dopant.
- a p-type dopant for example, Al x Ga 1-x N, which is a mixed crystal of gallium nitride and AlN, is used as a p-type layer by doping Mg, and Al x Ga 1-x N is used as an n-type layer by doping Si. be able to.
- gallium nitride is mixed with AlN, the band gap is widened, and the emission wavelength can be shifted to a higher energy side.
- gallium nitride may be mixed with InN, whereby the band gap is narrowed and the emission wavelength can be shifted to a lower energy side.
- the p-type gallium nitride layer and the n-type gallium nitride layer it is composed of a mixed crystal of GaN with one or more selected from the group consisting of GaN or AlN and InN having a smaller band gap than both layers.
- You may have an active layer at least.
- the active layer has a double heterojunction structure with a p-type layer and an n-type layer, and the thinned structure of the active layer corresponds to a light emitting device having a quantum well structure which is an embodiment of a pn junction, and has a luminous efficiency.
- the active layer may be made of a mixed crystal of GaN having one or more selected from the group consisting of GaN or AlN and InN having a smaller band gap than either one of the two layers. Even in such a single heterojunction, the luminous efficiency can be further increased.
- the gallium nitride buffer layer may be made of non-doped GaN, n-type or p-type doped GaN, and selected from the group consisting of AlN, InN, or GaN, AlN, and InN having a close lattice constant. It may be mixed with one or more kinds of crystals.
- the light emitting functional layer 14 may be composed of a plurality of material systems selected from gallium nitride (GaN) -based materials, zinc oxide (ZnO) -based materials, and aluminum nitride (AlN) -based materials.
- GaN gallium nitride
- ZnO zinc oxide
- AlN aluminum nitride
- a p-type gallium nitride layer and an n-type zinc oxide layer may be grown on the polycrystalline gallium nitride free-standing substrate 12, and the stacking order of the p-type gallium nitride layer and the n-type zinc oxide layer may be reversed.
- an n-type or p-type zinc oxide layer may be formed.
- the p-type dopant used for the p-type zinc oxide layer include nitrogen (N), phosphorus (P), arsenic (As), carbon (C), lithium (Li), sodium (Na), potassium ( K), one or more selected from the group consisting of silver (Ag) and copper (Cu).
- n-type dopant used for the n-type zinc oxide layer include aluminum (Al), gallium (Ga), indium (In), boron (B), fluorine (F), chlorine (Cl), One or more selected from the group consisting of bromine (Br), iodine (I), and silicon (Si) may be mentioned.
- the film formation method of the light emitting functional layer 14 and the buffer layer is not particularly limited as long as it is a method of growing substantially following the crystal orientation of the polycrystalline gallium nitride free-standing substrate, but a vapor phase method such as MOCVD, MBE, HVPE, sputtering, Preferred examples include a liquid phase method such as a Na flux method, an ammonothermal method, a hydrothermal method, and a sol-gel method, a powder method using solid phase growth of powder, and a combination thereof.
- a vapor phase method such as MOCVD, MBE, HVPE, sputtering
- Preferred examples include a liquid phase method such as a Na flux method, an ammonothermal method, a hydrothermal method, and a sol-gel method, a powder method using solid phase growth of powder, and a combination thereof.
- a gas for example, ammonia
- an organometallic gas for example, trimethyl gallium
- gallium (Ga) and nitrogen (N) On the substrate as a raw material and grown in a temperature range of about 300 to 1200 ° C. in an atmosphere containing hydrogen, nitrogen, or both.
- organometallic gases containing indium (In), aluminum (Al), silicon (Si) and magnesium (Mg) as n-type and p-type dopants for example, trimethylindium, trimethylaluminum, monosilane, disilane) Bis-cyclopentadienylmagnesium
- n-type and p-type dopants for example, trimethylindium, trimethylaluminum, monosilane, disilane
- Bis-cyclopentadienylmagnesium may be appropriately introduced to form a film.
- a seed crystal layer may be formed on the polycrystalline gallium nitride free-standing substrate.
- any method may be used as long as it promotes crystal growth substantially following the crystal orientation.
- a zinc oxide-based material is used for a part or all of the light emitting functional layer 14
- an ultrathin zinc oxide seed crystal is prepared by vapor phase growth methods such as MOCVD, MBE, HVPE, and sputtering. May be.
- the electrode layer 16 and / or the phosphor layer may be further provided on the light emitting functional layer 14.
- the electrode is also formed on the bottom surface of the polycrystalline gallium nitride free-standing substrate 12 as shown in FIG.
- the layer 18 can be provided, the polycrystalline gallium nitride free-standing substrate 12 may be used as the electrode itself, and in that case, it is preferable that an n-type dopant is added to the polycrystalline gallium nitride free-standing substrate 12. .
- the electrode layers 16 and 18 may be made of a known electrode material.
- the electrode layer 16 on the light emitting functional layer 14 is a transparent conductive film such as ITO, or a metal electrode having a high aperture ratio such as a lattice structure, This is preferable in that the extraction efficiency of light generated in the light emitting functional layer 14 can be increased.
- a phosphor layer for converting ultraviolet light into visible light may be provided outside the electrode layer.
- the phosphor layer is not particularly limited as long as it includes a known fluorescent component capable of converting ultraviolet light into visible light.
- a fluorescent component that emits blue light when excited by ultraviolet light, a fluorescent component that emits blue to green light when excited by ultraviolet light, and a fluorescent component that emits red light when excited by ultraviolet light are mixed. It is preferable that the white color is obtained as a mixed color.
- Preferred combinations of such fluorescent components include (Ca, Sr) 5 (PO 4 ) 3 Cl: Eu, BaMgAl 10 O 17 : Eu, and Mn, Y 2 O 3 S: Eu, and these components Is preferably dispersed in a resin such as a silicone resin to form a phosphor layer.
- a fluorescent component is not limited to the above-exemplified substances, but may be a combination of other ultraviolet light-excited phosphors such as yttrium aluminum garnet (YAG), silicate phosphors, and oxynitride phosphors. .
- a phosphor layer for converting blue light into yellow light may be provided outside the electrode layer.
- the phosphor layer is not particularly limited as long as it includes a known fluorescent component capable of converting blue light into yellow light. For example, it may be combined with a phosphor emitting yellow light such as YAG. By doing in this way, since blue light emission which permeate
- the phosphor layer includes both a fluorescent component that converts blue light into yellow and a fluorescent component that converts ultraviolet light into visible light, thereby converting ultraviolet light into visible light and blue light yellow. It is good also as a structure which performs both conversion to light.
- the polycrystalline gallium nitride free-standing substrate of the present invention can be preferably used for various applications such as various electronic devices, power devices, light receiving elements, solar cell wafers as well as the above-described light emitting elements.
- Example A1 Ge-doped gallium nitride free-standing substrate (1) Production of c-plane oriented alumina sintered body (1a) Production of laminate Fine alumina powder (TM-DAR (average particle size 0.1 ⁇ m), manufactured by Daimei Chemical) 100 mass Parts, magnesium oxide (500A, manufactured by Ube Materials) 0.0125 parts by mass (125 ppm by mass), polyvinyl butyral (product number BM-2, manufactured by Sekisui Chemical Co., Ltd.) 7.8 parts by mass as a binder, and plasticizer 3.9 parts by mass of di (2-ethylhexyl) phthalate (manufactured by Kurokin Kasei), 2 parts by mass of sorbitan trioleate (Leodol SP-O30, manufactured by Kao) as a dispersant, and 2-ethylhexanol as a dispersion medium And mixed.
- TM-DAR laminate Fine alumina powder
- TM-DAR average particle
- the amount of the dispersion medium was adjusted so that the slurry viscosity was 20000 cP.
- the slurry thus prepared was molded into a sheet shape on a PET film by a doctor blade method so that the thickness after drying was 40 ⁇ m, and a fine alumina powder layer was formed.
- a commercially available plate-like alumina powder (manufactured by Kinsei Matech, grade YFA10030) was classified with an airflow classifier (TC-15N, manufactured by Nisshin Engineering) at a classification point of 3 ⁇ m.
- the plate-like alumina powder from which coarse particles were removed in this way was crushed with a cobblestone having a diameter of 0.3 mm for 20 hours with a pot crusher, and finally the fine powder was removed with a water tank.
- 500 parts by mass of isopropyl alcohol was added as a dispersion medium.
- the obtained dispersion (plate-like alumina slurry) was dispersed with an ultrasonic disperser for 5 minutes, and then sprayed with a spray gun (Tamiya Spray Work HG Airbrush Wide) at a spray pressure of 0.2 MPa and a spray distance of 20 cm.
- the fine alumina powder layer was sprayed on one side to obtain a single-side processed body.
- the coverage of the surface of the fine alumina powder layer covered with the plate-like alumina powder was 1%.
- the coverage of the single-sided processed body was calculated as follows.
- the surface of the fine alumina powder layer is observed with an optical microscope, and this observation photograph is separated into a plate-like alumina powder portion and the other by image processing, and the plate-like alumina powder with respect to the area of the fine alumina powder layer surface in the observation photograph
- the area ratio was defined as the coverage.
- the obtained single-sided processed body was cut into a circle with a diameter of 60 mm, then peeled off from the PET film, laminated in 65 layers so that the sprayed processed surfaces do not overlap, and placed on an Al plate having a thickness of 10 mm, and then packaged. It was made into a vacuum pack by putting the inside into a vacuum and making it vacuum. This vacuum pack was hydrostatically pressed at a pressure of 100 kgf / cm 2 in 85 ° C. warm water to obtain a laminate.
- a seed crystal layer was formed on the processed oriented alumina substrate by MOCVD. More specifically, after depositing a low-temperature GaN layer of 30 nm in a hydrogen atmosphere as a buffer layer at a susceptor temperature of 530 ° C., the temperature is raised to a susceptor temperature of 1050 ° C. in a nitrogen / hydrogen atmosphere, and GaN having a thickness of 3 ⁇ m. A film was laminated to obtain a seed crystal substrate.
- the alumina crucible was placed on a table that can rotate the crystal growth furnace.
- a gallium nitride crystal was grown while stirring by rotating the solution while maintaining the temperature at 870 ° C. and 3.5 MPa in a nitrogen atmosphere for 100 hours.
- After completion of the crystal growth it was gradually cooled to room temperature over 3 hours, and the growth vessel was taken out of the crystal growth furnace.
- the melt composition remaining in the crucible was removed using ethanol, and the sample on which the gallium nitride crystal was grown was collected. In the obtained sample, a Ge-doped gallium nitride crystal was grown on the entire surface of a 60 mm seed crystal substrate, and the thickness of the crystal was about 1.4 mm. Cracks were not confirmed.
- the oriented alumina substrate portion of the sample thus obtained was removed by grinding with a grindstone to obtain a Ge-doped gallium nitride simple substance.
- the plate surface of the Ge-doped gallium nitride crystal was polished to flatten the plate surface. Further, the surface of the plate was smoothed by using lapping and CMP to obtain a Ge-doped polycrystalline gallium nitride free-standing substrate having a thickness of about 500 ⁇ m.
- the arithmetic average roughness Ra after processing of the surface of the polycrystalline gallium nitride free-standing substrate was 0.2 nm.
- an n-type semiconductor was formed by doping germanium.
- different elements may be doped or non-doped depending on the application and structure.
- the cross-sectional average diameter of the top surface is about 140 ⁇ m
- the cross-sectional average diameter of the bottom surface is about 66 ⁇ m. there were.
- the cross-sectional average diameter as is it is larger than the bottom surface of the upper surface, the ratio D T / D B sectional average diameter D T of the substrate top surface to its section average diameter D B of the bottom surface of the substrate was about 2.1.
- the aspect ratio T / DT of the GaN single crystal particles calculated as the ratio of the thickness T of the GaN crystal to the average cross-sectional diameter DT of the upper surface was about 3.6.
- the interface can be clearly discriminated by the scanning microscope image on the upper surface.
- the above evaluation may be performed after performing a process for making the interface stand out by thermal etching or chemical etching. Moreover, you may perform said evaluation using the crystal grain mapping image of the EBSD measurement mentioned later.
- the frequency of the inclination angle from the c-axis direction of the outermost surface constituent particles and the average inclination angle were calculated.
- the frequency of the inclination angle and the average inclination angle were calculated after performing reverse pole figure orientation mapping and performing image cleanup by the Grain Dilation method using the analysis software OIM Analysis.
- the conditions for cleanup are as follows. ⁇ Cleanup conditions for EBSD analysis> ⁇ Grain tolerance angle: 5 ° ⁇ Minimum Grain Size: 2 pixels
- Each particle constituting the gallium nitride crystal was generally oriented in the normal direction on the c-plane.
- the average inclination angle of the particles constituting the outermost surface was 0.9 °, which was a distribution state approximated to a Gaussian distribution.
- Example A2 Ge-doped gallium nitride free-standing substrate (1) Production of Ge-doped polycrystalline gallium nitride free-standing substrate (1a) Formation of seed crystal layer Orientation was performed in the same manner as in Example A1, except that the thickness of the buffer layer was 4 nm An Al2O3 substrate was produced, and a seed crystal layer was formed using MOCVD.
- the oriented alumina substrate portion of the sample thus obtained was removed by grinding with a grindstone to obtain a Ge-doped gallium nitride simple substance.
- the plate surface of the Ge-doped gallium nitride crystal was polished to flatten the plate surface. Further, the surface of the plate was smoothed by using lapping and CMP to obtain a Ge-doped polycrystalline gallium nitride free-standing substrate having a thickness of about 500 ⁇ m.
- the arithmetic average roughness Ra after processing of the upper surface of the polycrystalline gallium nitride free-standing substrate was 0.2 nm.
- the cross-sectional average diameter of the GaN single crystal particles on the top and bottom surfaces of the polycrystalline gallium nitride free-standing substrate using the same method as in Example A1
- the cross-sectional average diameter of the top surface is about 160 ⁇ m
- the cross-sectional average diameter of the bottom surface is about 66 ⁇ m. there were.
- the cross-sectional average diameter as is it is larger than the bottom surface of the upper surface, the ratio D T / D B sectional average diameter DT of top surface of the substrate with respect to cross-sectional average diameter D B of the bottom surface of the substrate was about 2.4.
- the aspect ratio T / DT of the GaN single crystal particles calculated as the ratio of the thickness T of the GaN crystal to the average cross-sectional diameter DT of the upper surface was about 3.1.
- the c-plane of each particle constituting the gallium nitride crystal was generally oriented in the normal direction.
- the average inclination angle was 0.7 °.
- Example A3 Ge-doped gallium nitride free-standing substrate (1) Production of c-plane oriented alumina sintered body (1a) Production of laminate Fine alumina powder (TM-DAR (average particle size 0.1 ⁇ m), manufactured by Daimei Chemical ) Magnesium oxide (500A, Ube Materials) 0.0125 parts by mass (125 ppm by mass) and polyvinyl butyral (product number BM-2, manufactured by Sekisui Chemical Co., Ltd.) 7.8 parts by mass with respect to 100 parts by mass 3.9 parts by weight of di (2-ethylhexyl) phthalate (manufactured by Kurokin Kasei) as a plasticizer, 2 parts by weight of sorbitan trioleate (Leodol SP-O30, manufactured by Kao) as a dispersant, and 2- Ethylhexanol was added and mixed.
- TM-DAR laminate Fine alumina powder
- BM-2 polyvinyl butyral
- the amount of the dispersion medium was adjusted so that the slurry viscosity was 20000 cP.
- the slurry thus prepared was molded into a sheet shape on a PET film by a doctor blade method so that the thickness after drying was 40 ⁇ m, and a fine alumina powder layer was formed.
- the amount of the dispersion medium was adjusted so that the slurry viscosity was 5000 cP.
- the slurry thus prepared was molded into a sheet shape on a PET film so as to have a thickness after drying of 3 ⁇ m on a PET film by a reverse doctor blade method to obtain a plate-like alumina powder layer.
- the fine alumina powder layer and the plate-like alumina powder layer peeled off from the PET film are alternately laminated to each other, placed on an Al plate having a thickness of 10 mm, and then put in a package to make the inside vacuum. And made a vacuum pack.
- This vacuum pack was hydrostatically pressed at a pressure of 100 kgf / cm 2 in warm water at 85 ° C. to obtain a laminate. At this time, the coverage of the plate-like alumina powder layer covering the surface of the fine alumina powder layer was 60%.
- the oriented alumina substrate portion of the sample thus obtained was removed by grinding with a grindstone to obtain a Ge-doped gallium nitride simple substance.
- the plate surface of the Ge-doped gallium nitride crystal was polished to flatten the plate surface. Further, the surface of the plate was smoothed by using lapping and CMP to obtain a Ge-doped polycrystalline gallium nitride free-standing substrate having a thickness of about 500 ⁇ m.
- the arithmetic average roughness Ra after processing of the upper surface of the polycrystalline gallium nitride free-standing substrate was 0.2 nm.
- the cross-sectional average diameter of the GaN single crystal particles on the top and bottom surfaces of the polycrystalline gallium nitride free-standing substrate using the same method as in Example A1
- the cross-sectional average diameter of the top surface is about 91 ⁇ m and the cross-sectional average diameter of the bottom surface is about 46 ⁇ m. there were.
- the cross-sectional average diameter as is it is larger than the bottom surface of the upper surface the ratio D T / D B sectional average diameter D T of the substrate top surface to its section average diameter D B of the bottom surface of the substrate was about 2.0.
- the aspect ratio T / DT of the GaN single crystal particles calculated as the ratio of the thickness T of the GaN crystal to the average cross-sectional diameter DT of the upper surface was about 5.5.
- the c-plane of each particle constituting the gallium nitride crystal was generally oriented in the normal direction.
- the average inclination angle was 2.2 °.
- Example A4 Ge-doped gallium nitride free-standing substrate (1) Production of c-plane oriented alumina sintered body Fine alumina powder (grade TM-DAR, manufactured by Daimei Chemical Industry Co., Ltd.) 99.6 parts by weight, yttria powder (Shin-Etsu) Chemical Industry Co., Ltd., grade UU) 0.2 parts by mass, magnesium oxide (500A, manufactured by Ube Materials) 0.2 part by mass, and added at a rate of 50 cc of water as a solvent to 100 g of the mixed powder, The mixture was pulverized for 40 hours in a ball mill to form a slurry.
- Fine alumina powder grade TM-DAR, manufactured by Daimei Chemical Industry Co., Ltd.
- yttria powder Shin-Etsu Chemical Industry Co., Ltd., grade UU
- magnesium oxide 500A, manufactured by Ube Materials
- the obtained slurry was poured into a gypsum mold having an inner diameter of 50 mm and placed in a 12 T magnetic field for 3 hours for casting.
- the molded body was demolded from gypsum, dried at room temperature, and then fired using a graphite mold in a hot press at 1975 ° C. for 4 hours under a surface pressure of 200 kgf / cm 2 .
- the sintered body thus obtained was fixed to a ceramic surface plate and ground to # 2000 using a grindstone to flatten the plate surface.
- the surface of the plate was smoothed by lapping using diamond abrasive grains, and an oriented alumina sintered body having a diameter of 50 mm and a thickness of 0.5 mm was obtained as an oriented alumina substrate.
- the flatness was improved while gradually reducing the size of the abrasive grains from 3 ⁇ m to 0.5 ⁇ m.
- the arithmetic average roughness Ra after processing was 4 nm.
- a seed crystal layer was formed on the processed oriented alumina substrate by MOCVD. Specifically, after depositing an InGaN layer of 6 nm in a nitrogen atmosphere as a buffer layer in a susceptor temperature of 700 ° C., the temperature is raised to a susceptor temperature of 1050 ° C., and a GaN film having a thickness of 3 ⁇ m is formed in a nitrogen and hydrogen atmosphere. A seed crystal substrate was obtained by laminating. The In composition in the InGaN layer was set to 15 mol%.
- the oriented alumina substrate portion of the sample thus obtained was removed by grinding with a grindstone to obtain a Ge-doped gallium nitride simple substance.
- the plate surface of the Ge-doped gallium nitride crystal was polished to flatten the plate surface. Further, the surface of the plate was smoothed by using lapping and CMP to obtain a Ge-doped polycrystalline gallium nitride free-standing substrate having a thickness of about 500 ⁇ m.
- the arithmetic average roughness Ra after processing of the upper surface of the polycrystalline gallium nitride free-standing substrate was 0.2 nm.
- the cross-sectional average diameter of the top surface is about 100 ⁇ m and the cross-sectional average diameter of the bottom surface is about 80 ⁇ m. there were.
- the cross-sectional average diameter of the top surface is larger than that of the bottom surface, and the ratio D T / D B of the cross-sectional average diameter D T of the substrate top surface to the cross-sectional average diameter DB of the substrate bottom surface is about 1.3.
- the aspect ratio T / DT of the GaN single crystal particles calculated as the ratio of the thickness T of the GaN crystal to the average cross-sectional diameter DT of the upper surface was about 5.0.
- the c-plane of each particle constituting the gallium nitride crystal was generally oriented in the normal direction.
- the average inclination angle was 0.05 °.
- Example A5 Ge-doped gallium nitride free-standing substrate (1) Production of c-plane oriented alumina sintered body 99.8 parts by mass of fine alumina powder (manufactured by Daimei Chemical Co., Ltd., Grade TM-DAR), yttria powder (Shin-Etsu) Chemical U.S. Co., grade UU) 0.2 parts by mass was mixed, added to 100 g of the mixed powder as a solvent at a rate of 50 cc of water, mixed and ground in a ball mill for 40 hours, and slurried.
- fine alumina powder manufactured by Daimei Chemical Co., Ltd., Grade TM-DAR
- yttria powder Shin-Etsu Chemical U.S. Co., grade UU
- the obtained slurry was poured into a gypsum mold having an inner diameter of 50 mm and placed in a 12 T magnetic field for 3 hours for casting.
- the molded body was demolded from gypsum, dried at room temperature, and then fired using a graphite mold in a hot press at 1400 ° C. for 4 hours under a surface pressure of 200 kgf / cm 2 .
- the sintered body thus obtained was fixed to a ceramic surface plate and ground to # 2000 using a grindstone to flatten the plate surface.
- the surface of the plate was smoothed by lapping using diamond abrasive grains, and an oriented alumina sintered body having a diameter of 50 mm and a thickness of 0.5 mm was obtained as an oriented alumina substrate.
- the flatness was improved while gradually reducing the size of the abrasive grains from 3 ⁇ m to 0.5 ⁇ m.
- the arithmetic average roughness Ra after processing was 4 nm.
- the oriented alumina substrate portion of the sample thus obtained was removed by grinding with a grindstone to obtain a Ge-doped gallium nitride simple substance.
- the plate surface of the Ge-doped gallium nitride crystal was polished to flatten the plate surface. Furthermore, the surface of the plate was smoothed using lapping and CMP to obtain a Ge-doped polycrystalline gallium nitride free-standing substrate having a thickness of about 70 ⁇ m.
- the arithmetic average roughness Ra after processing of the upper surface of the polycrystalline gallium nitride free-standing substrate was 0.5 nm.
- the cross-sectional average diameter of the GaN single crystal particles on the top and bottom surfaces of the polycrystalline gallium nitride free-standing substrate using the same method as Example A1
- the cross-sectional average diameter of the top surface is about 9 ⁇ m and the cross-sectional average diameter of the bottom surface is about 8 ⁇ m. there were.
- the cross-sectional average diameter as is it is larger than the bottom surface of the upper surface the ratio D T / D B sectional average diameter D T of the substrate top surface to its section average diameter D B of the bottom surface of the substrate was about 1.1.
- the aspect ratio T / DT of the GaN single crystal particles calculated as the ratio of the thickness T of the GaN crystal to the average cross-sectional diameter DT of the upper surface was about 7.8.
- the c-plane of each particle constituting the gallium nitride crystal was generally oriented in the normal direction.
- the average inclination angle was 0.8 °.
- Example B1 Light-Emitting Element Using Ge-Doped Polycrystalline Gallium Nitride Free-standing Substrate (1) Production of Light-Emitting Element Using the MOCVD method, an n-type layer is formed on each Ge-doped polycrystalline gallium nitride free-standing substrate produced in Examples A1 to A5 As a result, an n-GaN layer doped to have a Si atom concentration of 5 ⁇ 10 18 / cm 3 at 1050 ° C. was deposited by 1 ⁇ m. Next, a multiple quantum well layer was deposited at 750 ° C. as a light emitting layer.
- a Ti / Al / Ni / Au film as a cathode electrode is formed on the surface opposite to the n-GaN layer and the p-GaN layer of the polycrystalline gallium nitride free-standing substrate, respectively.
- Patterning was performed with thicknesses of 15 nm, 70 nm, 12 nm, and 60 nm. Thereafter, a heat treatment at 700 ° C. in a nitrogen atmosphere was performed for 30 seconds in order to improve the ohmic contact characteristics.
- a Ni / Au film as a light-transmitting anode electrode was patterned on the p-type layer to a thickness of 6 nm and 12 nm, respectively. Thereafter, a heat treatment at 500 ° C. was performed for 30 seconds in a nitrogen atmosphere in order to improve the ohmic contact characteristics. Further, by using photolithography and vacuum deposition, a Ni / Au film serving as an anode electrode pad is patterned to a thickness of 5 nm and 60 nm on a partial region of the upper surface of the Ni / Au film serving as a translucent anode electrode, respectively. did. The wafer thus obtained was cut into chips and further mounted on a lead frame to obtain a light emitting device having a vertical structure.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Crystallography & Structural Chemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Computer Hardware Design (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Inorganic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Electromagnetism (AREA)
- General Physics & Mathematics (AREA)
- Led Devices (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Chemical Vapour Deposition (AREA)
Abstract
Description
該基板上に形成され、略法線方向に単結晶構造を有する複数の半導体単結晶粒子で構成される層を一以上有する発光機能層と、
を備えた、発光素子が提供される。
本発明の窒化ガリウム基板は自立基板の形態を有しうる。本発明において「自立基板」とは、取り扱う際に自重で変形又は破損せず、固形物として取り扱うことのできる基板を意味する。本発明の多結晶窒化ガリウム自立基板は発光素子等の各種半導体デバイスの基板として使用可能であるが、それ以外にも、電極(p型電極又はn型電極でありうる)、p型層、n型層等の基材以外の部材又は層として使用可能なものである。なお、以下の説明においては、主たる用途の一つである発光素子を例に本発明の利点を記述することがあるが、同様ないし類似の利点は技術的整合性を損なわない範囲内で他の半導体デバイスにも当てはまる。
本発明の多結晶窒化ガリウム自立基板の製造方法は特に限定されないが、以下に好ましい3つの手法を例示する。いずれの手法も、下地基板としての配向多結晶焼結体上に多結晶窒化ガリウム層を作製する点においては共通する。
本発明の多結晶窒化ガリウム自立基板の製造に下地基材として用いる配向多結晶焼結体は、いかなる製造方法によって製造されたものであってもよく、特に限定されない。例えば特許文献3(WO2015/151902A1)に記載される方法に基づいて作製されたものであってもよい。
上述した本発明による多結晶窒化ガリウム自立基板を用いて高品質の発光素子を作製することができる。前述のとおり、本発明による多結晶窒化ガリウム自立基板を用いて発光素子を構成することにより、高い発光効率を得ることができる。本発明の多結晶窒化ガリウム自立基板を用いた発光素子の構造やその作製方法は特に限定されるものではない。典型的には、発光素子は、多結晶窒化ガリウム自立基板に発光機能層を設けることにより作製され、この発光機能層の形成は、窒化ガリウム基板の結晶方位に概ね倣った結晶方位を有するように、略法線方向に単結晶構造を有する複数の半導体単結晶粒子で構成される層を一つ以上形成することに行われるのが好ましい。もっとも、多結晶窒化ガリウム自立基板を電極(p型電極又はn型電極でありうる)、p型層、n型層等の基材以外の部材又は層として利用して発光素子を作製してもよい。素子サイズに特に規定はなく、5mm×5mm以下の小素子としてもよいし、10cm×10cm以上の面発光素子としてもよい。
本発明の多結晶窒化ガリウム自立基板は、上述した発光素子のみならず、各種電子デバイス、パワーデバイス、受光素子、太陽電池用ウェハー等の種々の用途に好ましく利用することができる。
(1)c面配向アルミナ焼結体の作製
(1a)積層体の作製
微細アルミナ粉末(TM-DAR(平均粒径0.1μm)、大明化学製)100質量部に対し、酸化マグネシウム(500A、宇部マテリアルズ製)0.0125質量部(125質量ppm)と、バインダーとしてポリビニルブチラール(品番BM-2、積水化学工業製)7.8質量部と、可塑剤としてジ(2-エチルヘキシル)フタレート(黒金化成製)3.9質量部と、分散剤としてトリオレイン酸ソルビタン(レオドールSP-O30、花王製)2質量部と、分散媒として2-エチルヘキサノールとを加えて混合した。分散媒の量は、スラリー粘度が20000cPとなるように調整した。このようにして調製されたスラリーを、ドクターブレード法によってPETフィルムの上に乾燥後の厚みが40μmとなるようにシート状に成形し、微細アルミナ粉末層とした。
得られた積層体を脱脂炉中に配置し、600℃で10時間の条件で脱脂を行った。得られた脱脂体を黒鉛製の型を用い、ホットプレスにて窒素中、焼成温度(最高到達温度)1975℃で4時間、面圧200kgf/cm2の条件で焼成し、アルミナ焼結体を得た。なお、焼成温度から降温する際に1200℃までプレス圧を維持し、1200℃未満の温度域ではプレス圧をゼロに開放した。
このようにして得た焼結体をセラミックスの定盤に固定し、砥石を用いて#2000まで研削して板面を平坦にした。次いで、ダイヤモンド砥粒を用いたラップ加工により、板面を平滑化し、口径60mm、厚さ0.5mmの配向アルミナ焼結体を配向アルミナ基板として得た。砥粒のサイズを3μmから0.5μmまで段階的に小さくしつつ、平坦性を高めた。加工後の算術平均粗さRaは4nmであった。
(2a)種結晶層の成膜
次に、加工した配向アルミナ基板の上に、MOCVD法を用いて種結晶層を形成した。具体的には、バッファ層としてサセプタ(susceptor)温度530℃、水素雰囲気中にて低温GaN層を30nm堆積させた後に、窒素・水素雰囲気にてサセプタ温度1050℃まで昇温し厚さ3μmのGaN膜を積層させて種結晶基板を得た。
上記工程で作製した種結晶基板を、内径80mm、高さ45mmの円筒平底のアルミナ坩堝の底部分に設置し、次いで融液組成物をグローブボックス内で坩堝内に充填した。融液組成物の組成は以下のとおりである。
・金属Ga:60g
・金属Na:60g
・四塩化ゲルマニウム:1.85g
多結晶窒化ガリウム自立基板の最表面におけるGaN単結晶粒子の断面平均径を測定するため、自立基板の上面を走査電子顕微鏡にて画像を撮影した。視野範囲は、得られる画像の対角線に直線を引いた場合に、10個から30個の柱状組織と交わるような直線が引けるような視野範囲とした。得られた画像の対角線に2本の直線を任意に引き、直線が交わる全ての粒子に対し、個々の粒子の内側の線分の長さを平均したものに1.5を乗じた値を、多結晶窒化ガリウム自立基板の最表面におけるGaN単結晶粒子の断面平均径とした。
電子線後方散乱回折装置(EBSD)(TSLソリューションズ製、OIM)を取り付けたSEM(日本電子製、JSM-7000F)にて多結晶窒化ガリウム自立基板の板面の逆極点図方位マッピングを500μm×500μmの視野で実施した。このEBSD測定の諸条件は以下のとおりとした。
<EBSD測定条件>
・加速電圧:15kV
・照射電流:2×10-8A
・ワークディスタンス:15mm
・ステップ幅:2μm
・測定プログラム:OIM Data Collection
<EBSD解析時のクリーンアップ条件>
・Grain tolerance Angle:5°
・Minimum Grain Size:2ピクセル
(1)Geドープ多結晶窒化ガリウム自立基板の作製
(1a)種結晶層の成膜
バッファ層の厚みを4nmとした以外は、例A1と同様の方法で配向Al2O3基板を作製し、MOCVD法を用いて種結晶層を形成した。
Caを0.1g添加した以外は例A1と同様の方法でGeドープGaN層を成膜した。得られた試料は、60mmの種結晶基板の全面上にGeドープ窒化ガリウム結晶が成長しており、結晶の厚さは約1.2mmであった。クラックは確認されなかった。
(1)c面配向アルミナ焼結体の作製
(1a)積層体の作製
微細アルミナ粉末(TM-DAR(平均粒径0.1μm)、大明化学製)100質量部に対し、酸化マグネシウム(500A、宇部マテリアルズ製)0.0125質量部(125質量ppm)と、バインダーとしてポリビニルブチラール(品番BM-2、積水化学工業製)7.8質量部と、可塑剤としてジ(2-エチルヘキシル)フタレート(黒金化成製)3.9質量部と、分散剤としてトリオレイン酸ソルビタン(レオドールSP-O30、花王製)2質量部と、分散媒として2-エチルヘキサノールとを加えて混合した。分散媒の量は、スラリー粘度が20000cPとなるように調整した。このようにして調製されたスラリーを、ドクターブレード法によってPETフィルムの上に乾燥後の厚みが40μmとなるようにシート状に成形し、微細アルミナ粉末層とした。
得られた積層体を脱脂炉中に配置し、600℃で10時間の条件で脱脂を行った。得られた脱脂体を黒鉛製の型を用い、ホットプレスにて窒素中、焼成温度(最高到達温度)1975℃で4時間、面圧200kgf/cm2の条件で焼成し、アルミナ焼結体を得た。なお、焼成温度から降温する際に1200℃までプレス圧を維持し、1200℃未満の温度域ではプレス圧をゼロに開放した。
このようにして得た焼結体をセラミックスの定盤に固定し、砥石を用いて#2000まで研削して板面を平坦にした。次いで、ダイヤモンド砥粒を用いたラップ加工により、板面を平滑化し、口径60mm、厚さ0.5mmの配向アルミナ焼結体を配向アルミナ基板として得た。砥粒のサイズを3μmから0.5μmまで段階的に小さくしつつ、平坦性を高めた。加工後の算術平均粗さRaは4nmであった。
例A1と同様の方法で、MOCVD法を用いて種結晶層を形成した。その後、例A1と同様の方法でGeドープGaN層を成膜した。得られた試料は、60mmの種結晶基板の全面上にGeドープ窒化ガリウム結晶が成長しており、結晶の厚さは約1.3mmであった。クラックは確認されなかった。
(1)c面配向アルミナ焼結体の作製
微細アルミナ粉末(大明化学工業株式会社製、グレードTM-DAR)99.6質量部、イットリア粉末(信越化学工業株式会社製、グレードUU)0.2質量部、酸化マグネシウム(500A、宇部マテリアルズ製)0.2質量部を混合し、混合粉末100gに対して溶媒として水50ccの割合で添加し、ボールミルにて40時間混合粉砕し、スラリー化した。得られたスラリーを内径50mmの石膏型に注ぎ、12Tの磁場中で3時間戴置し、鋳込み成形を行った。成形体は石膏から脱型し、室温での乾燥後、黒鉛製の型を用い、ホットプレスにて窒素中1975℃で4時間、面圧200kgf/cm2の条件で焼成した。
(2a)種結晶層の成膜
次に、加工した配向アルミナ基板の上に、MOCVD法を用いて種結晶層を形成した。具体的には、バッファ層としてサセプタ温度700℃、窒素雰囲気中にてInGaN層を6nm堆積させた後に、サセプタ温度1050℃まで昇温し、窒素および水素雰囲気中にて厚さ3μmのGaN膜を積層させて種結晶基板を得た。InGaN層中のIn組成は15モル%となるように設定した。
Caを0.1g添加した以外は例A1と同様の方法でGeドープGaN層を成膜した。得られた試料は、60mmの種結晶基板の全面上にGeドープ窒化ガリウム結晶が成長しており、結晶の厚さは約1.2mmであった。クラックは確認されなかった。
(1)c面配向アルミナ焼結体の作製
微細アルミナ粉末(大明化学工業株式会社製、グレードTM-DAR)99.8質量部、イットリア粉末(信越化学工業株式会社製、グレードUU)0.2質量部を混合し、混合粉末100gに対して溶媒として水50ccの割合で添加し、ボールミルにて40時間混合粉砕し、スラリー化した。得られたスラリーを内径50mmの石膏型に注ぎ、12Tの磁場中で3時間戴置し、鋳込み成形を行った。成形体は石膏から脱型し、室温での乾燥後、黒鉛製の型を用い、ホットプレスにて窒素中1400℃で4時間、面圧200kgf/cm2の条件で焼成した。
例A1と同様の方法で、MOCVD法を用いて種結晶層を形成した。その後、窒素圧力を4.0MPaとし、かつ、昇温加圧後の保持時間を30時間としたこと以外は例A1と同様の方法でGeドープGaN層を成膜した。得られた試料は、50mmの種結晶基板の全面上にGeドープ窒化ガリウム結晶が成長しており、結晶の厚さは約0.3mmであった。クラックは確認されなかった。
(1)発光素子の作製
MOCVD法を用いて、例A1~A5で作製した各Geドープ多結晶窒化ガリウム自立基板上にn型層として1050℃でSi原子濃度が5×1018/cm3になるようにドーピングしたn-GaN層を1μm堆積した。次に発光層として750℃で多重量子井戸層を堆積した。具体的にはInGaNによる2.5nmの井戸層を5層、GaNによる10nmの障壁層を6層にて交互に積層した。次にp型層として950℃でMg原子濃度が1×1019/cm3になるようにドーピングしたp-GaNを200nm堆積した。その後、MOCVD装置から取り出し、p型層のMgイオンの活性化処理として、窒素雰囲気中で800℃の熱処理を10分間行った。
カソード電極とアノード電極間に通電し、I-V測定を行ったところ、例A1~A5のいずれの基板を用いた素子でも整流性が確認された。また、順方向の電流を流したところ、波長450nmの発光が確認された。発光輝度は例A1及びA2の基板を用いた素子が著しく高輝度であった。例A3の基板を用いた素子は許容可能な輝度ではあるが、例A1及びA2より輝度が低下した。例A4及びA5の基板を用いた素子は例A3によりも著しく輝度が低下した。
Claims (13)
- 略法線方向で特定結晶方位に配向した複数の窒化ガリウム系単結晶粒子で構成される多結晶窒化ガリウム自立基板であって、該多結晶窒化ガリウム自立基板が上面及び底面を有し、前記上面の電子線後方散乱回折法(EBSD)の逆極点図マッピングによって測定した各窒化ガリウム系単結晶粒子の結晶方位が特定結晶方位から様々な角度で傾斜して分布し、その平均傾斜角が0.1°以上1°未満であり、かつ、前記上面に露出している窒化ガリウム系単結晶粒子の最表面における断面平均径DTが10μm以上である、多結晶窒化ガリウム自立基板。
- 前記窒化ガリウム系単結晶粒子の傾斜角がガウス分布に従って分布してなる、請求項1に記載の多結晶窒化ガリウム自立基板。
- 前記多結晶窒化ガリウム自立基板が、略法線方向に単結晶構造を有する、請求項1又は2に記載の多結晶窒化ガリウム自立基板。
- 前記上面に露出している前記窒化ガリウム系単結晶粒子が、前記底面に粒界を介さずに連通してなる、請求項1~3のいずれか一項に記載の多結晶窒化ガリウム自立基板。
- 前記上面に露出している窒化ガリウム系単結晶粒子の最表面における断面平均径DTが、前記底面に露出している窒化ガリウム系単結晶粒子の最表面における断面平均径DBと異なる、請求項1~4のいずれか一項に記載の多結晶窒化ガリウム自立基板。
- 前記底面に露出している窒化ガリウム系単結晶粒子の最表面における断面平均径DBに対する、前記上面に露出している窒化ガリウム系単結晶粒子の最表面における断面平均径DTの比DT/DBが1.0よりも大きい、請求項1~5のいずれか一項に記載の多結晶窒化ガリウム自立基板。
- 20μm以上の厚さを有する、請求項1~6のいずれか一項に記載の多結晶窒化ガリウム自立基板。
- 直径50.8mm以上の大きさを有する、請求項1~7のいずれか一項に記載の多結晶窒化ガリウム自立基板。
- 前記窒化ガリウム系単結晶粒子がn型ドーパント又はp型ドーパントでドープされている、請求項1~8のいずれか一項に記載の多結晶窒化ガリウム自立基板。
- 前記窒化ガリウム系単結晶粒子がドーパントを含まない、請求項1~9のいずれか一項に記載の多結晶窒化ガリウム自立基板。
- 前記窒化ガリウム系単結晶粒子が混晶化されている、請求項1~10のいずれか一項に記載の多結晶窒化ガリウム自立基板。
- 前記多結晶窒化ガリウム自立基板を構成する前記窒化ガリウム系単結晶粒子の結晶方位が、基板法線方向と直交する板面方向では無配向である、請求項1~11のいずれか一項に記載の多結晶窒化ガリウム自立基板。
- 請求項1~12のいずれか一項に記載の多結晶窒化ガリウム自立基板と、
該基板上に形成され、略法線方向に単結晶構造を有する複数の半導体単結晶粒子で構成される層を一以上有する発光機能層と、
を備えた、発光素子。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP17756243.6A EP3421648B1 (en) | 2016-02-25 | 2017-02-10 | Polycrystalline gallium nitride self-supported substrate and light emitting element using the same |
CN201780005781.5A CN108699727B (zh) | 2016-02-25 | 2017-02-10 | 多晶氮化镓自立基板和使用该多晶氮化镓自立基板的发光元件 |
JP2018501574A JP6648253B2 (ja) | 2016-02-25 | 2017-02-10 | 多結晶窒化ガリウム自立基板及びそれを用いた発光素子 |
US16/059,250 US10707373B2 (en) | 2016-02-25 | 2018-08-09 | Polycrystalline gallium nitride self-supported substrate and light emitting element using same |
Applications Claiming Priority (10)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2016-034006 | 2016-02-25 | ||
JP2016034006 | 2016-02-25 | ||
JP2016-139508 | 2016-07-14 | ||
JP2016139508 | 2016-07-14 | ||
JPPCT/JP2016/078267 | 2016-09-26 | ||
PCT/JP2016/078264 WO2017086026A1 (ja) | 2015-11-16 | 2016-09-26 | 配向焼結体の製法 |
JPPCT/JP2016/078265 | 2016-09-26 | ||
PCT/JP2016/078267 WO2017057273A1 (ja) | 2015-09-30 | 2016-09-26 | 静電チャック |
PCT/JP2016/078265 WO2017057271A1 (ja) | 2015-09-30 | 2016-09-26 | エピタキシャル成長用配向アルミナ基板 |
JPPCT/JP2016/078264 | 2016-09-26 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US16/059,250 Continuation US10707373B2 (en) | 2016-02-25 | 2018-08-09 | Polycrystalline gallium nitride self-supported substrate and light emitting element using same |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2017145802A1 true WO2017145802A1 (ja) | 2017-08-31 |
Family
ID=59685158
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2017/004891 WO2017145802A1 (ja) | 2016-02-25 | 2017-02-10 | 多結晶窒化ガリウム自立基板及びそれを用いた発光素子 |
Country Status (5)
Country | Link |
---|---|
US (1) | US10707373B2 (ja) |
EP (1) | EP3421648B1 (ja) |
JP (1) | JP6648253B2 (ja) |
CN (1) | CN108699727B (ja) |
WO (1) | WO2017145802A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2023157547A1 (ja) * | 2022-02-17 | 2023-08-24 | 日本碍子株式会社 | Iii族元素窒化物半導体基板および貼り合わせ基板 |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN111201208B (zh) | 2017-10-05 | 2023-05-23 | 阔斯泰公司 | 氧化铝质烧结体及其制造方法 |
US11162189B2 (en) * | 2018-03-02 | 2021-11-02 | Dexerials Corporation | Semiconductor substrate, gallium nitride single crystal, and method for producing gallium nitride single crystal |
JP7428573B2 (ja) * | 2020-04-06 | 2024-02-06 | 株式会社東芝 | 発電素子、発電モジュール、発電装置、及び、発電システム |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010132556A (ja) | 1998-05-28 | 2010-06-17 | Sumitomo Electric Ind Ltd | n型窒化ガリウム単結晶基板 |
JP2012184144A (ja) | 2011-03-07 | 2012-09-27 | Tokuyama Corp | 窒化ガリウム結晶積層基板及びその製造方法 |
WO2015151902A1 (ja) | 2014-03-31 | 2015-10-08 | 日本碍子株式会社 | 多結晶窒化ガリウム自立基板及びそれを用いた発光素子 |
JP2015199635A (ja) * | 2013-12-18 | 2015-11-12 | 日本碍子株式会社 | 窒化ガリウム自立基板、発光素子及びそれらの製造方法 |
Family Cites Families (23)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5130209A (ja) | 1974-09-06 | 1976-03-15 | Matsushita Electric Ind Co Ltd | |
JPS6433055A (en) | 1987-07-27 | 1989-02-02 | Sumitomo Cement Co | Sintered body of alumina having high strength and its production |
JPH05270894A (ja) | 1992-03-27 | 1993-10-19 | Sumitomo Metal Ind Ltd | セラミックス基板の製造方法 |
JP3297571B2 (ja) | 1995-12-18 | 2002-07-02 | 京セラ株式会社 | 静電チャック |
JP3348140B2 (ja) | 1996-04-08 | 2002-11-20 | 住友大阪セメント株式会社 | 静電チャック |
US5754391A (en) | 1996-05-17 | 1998-05-19 | Saphikon Inc. | Electrostatic chuck |
US6529362B2 (en) | 1997-03-06 | 2003-03-04 | Applied Materials Inc. | Monocrystalline ceramic electrostatic chuck |
US5737178A (en) | 1997-03-06 | 1998-04-07 | Applied Materials, Inc. | Monocrystalline ceramic coating having integral bonding interconnects for electrostatic chucks |
JP3555442B2 (ja) | 1998-04-24 | 2004-08-18 | 住友金属工業株式会社 | プラズマ耐食性に優れたアルミナセラミックス材料およびその製造方法 |
JP4008230B2 (ja) | 2001-11-14 | 2007-11-14 | 住友大阪セメント株式会社 | 静電チャックの製造方法 |
JP2004359495A (ja) | 2003-06-04 | 2004-12-24 | Ngk Insulators Ltd | エピタキシャル膜用アルミナ基板 |
JP4744855B2 (ja) | 2003-12-26 | 2011-08-10 | 日本碍子株式会社 | 静電チャック |
JP4910390B2 (ja) | 2005-12-26 | 2012-04-04 | 株式会社村田製作所 | 圧電セラミックおよびその製造方法ならびに圧電共振子およびその製造方法 |
JP5281269B2 (ja) | 2007-02-26 | 2013-09-04 | 日本碍子株式会社 | セラミックスシート及び結晶配向セラミックスの製造方法 |
US20080248277A1 (en) | 2007-02-26 | 2008-10-09 | Ngk Insulators, Ltd. | Ceramic sheet, method for producing the same, and method for producing crystallographically-oriented ceramic |
JP2010018510A (ja) | 2007-12-27 | 2010-01-28 | Ngk Insulators Ltd | 結晶配向セラミックス |
US8211328B2 (en) | 2007-12-27 | 2012-07-03 | Ngk Insulators, Ltd. | Crystallographically-oriented ceramic |
JP2010163313A (ja) | 2009-01-15 | 2010-07-29 | Denso Corp | 結晶配向セラミックスの製造方法 |
KR20120012555A (ko) * | 2010-08-02 | 2012-02-10 | 광주과학기술원 | 점진적으로 굴절률이 변하는 실리콘 다층 무반사막 및 그 제조방법 및 이를 구비하는 태양전지 및 그 제조방법 |
JP4772918B1 (ja) * | 2010-12-21 | 2011-09-14 | エー・イー・テック株式会社 | 窒化ガリウム(GaN)自立基板の製造方法及び製造装置 |
US9312446B2 (en) * | 2013-05-31 | 2016-04-12 | Ngk Insulators, Ltd. | Gallium nitride self-supported substrate, light-emitting device and manufacturing method therefor |
JP5994757B2 (ja) * | 2013-09-17 | 2016-09-21 | トヨタ自動車株式会社 | 車両の制御装置 |
JP6474734B2 (ja) | 2013-12-18 | 2019-02-27 | 日本碍子株式会社 | 発光素子用複合基板及びその製造方法 |
-
2017
- 2017-02-10 WO PCT/JP2017/004891 patent/WO2017145802A1/ja active Application Filing
- 2017-02-10 JP JP2018501574A patent/JP6648253B2/ja active Active
- 2017-02-10 CN CN201780005781.5A patent/CN108699727B/zh active Active
- 2017-02-10 EP EP17756243.6A patent/EP3421648B1/en active Active
-
2018
- 2018-08-09 US US16/059,250 patent/US10707373B2/en active Active
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010132556A (ja) | 1998-05-28 | 2010-06-17 | Sumitomo Electric Ind Ltd | n型窒化ガリウム単結晶基板 |
JP2012184144A (ja) | 2011-03-07 | 2012-09-27 | Tokuyama Corp | 窒化ガリウム結晶積層基板及びその製造方法 |
JP2015199635A (ja) * | 2013-12-18 | 2015-11-12 | 日本碍子株式会社 | 窒化ガリウム自立基板、発光素子及びそれらの製造方法 |
WO2015151902A1 (ja) | 2014-03-31 | 2015-10-08 | 日本碍子株式会社 | 多結晶窒化ガリウム自立基板及びそれを用いた発光素子 |
Non-Patent Citations (1)
Title |
---|
See also references of EP3421648A4 |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2023157547A1 (ja) * | 2022-02-17 | 2023-08-24 | 日本碍子株式会社 | Iii族元素窒化物半導体基板および貼り合わせ基板 |
Also Published As
Publication number | Publication date |
---|---|
CN108699727B (zh) | 2021-06-11 |
JP6648253B2 (ja) | 2020-02-14 |
EP3421648A4 (en) | 2019-10-02 |
US10707373B2 (en) | 2020-07-07 |
CN108699727A (zh) | 2018-10-23 |
EP3421648B1 (en) | 2023-01-25 |
EP3421648A1 (en) | 2019-01-02 |
JPWO2017145802A1 (ja) | 2019-01-17 |
US20180351038A1 (en) | 2018-12-06 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5770905B1 (ja) | 窒化ガリウム自立基板、発光素子及びそれらの製造方法 | |
JP6480398B2 (ja) | 多結晶窒化ガリウム自立基板及びそれを用いた発光素子 | |
JP6474734B2 (ja) | 発光素子用複合基板及びその製造方法 | |
JP6890117B2 (ja) | 多結晶13族元素窒化物からなる自立基板及びそれを用いた発光素子 | |
WO2014192911A1 (ja) | 窒化ガリウム自立基板、発光素子及びそれらの製造方法 | |
US10707373B2 (en) | Polycrystalline gallium nitride self-supported substrate and light emitting element using same | |
KR102172356B1 (ko) | 질화갈륨 자립 기판, 발광 소자 및 이들의 제조 방법 | |
JP6684815B2 (ja) | エピタキシャル成長用配向アルミナ基板 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 2018501574 Country of ref document: JP |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2017756243 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: 2017756243 Country of ref document: EP Effective date: 20180925 |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 17756243 Country of ref document: EP Kind code of ref document: A1 |