WO2009093683A1 - 化合物半導体発光素子及びその製造方法、化合物半導体発光素子用導電型透光性電極、ランプ、電子機器並びに機械装置 - Google Patents
化合物半導体発光素子及びその製造方法、化合物半導体発光素子用導電型透光性電極、ランプ、電子機器並びに機械装置 Download PDFInfo
- Publication number
- WO2009093683A1 WO2009093683A1 PCT/JP2009/051062 JP2009051062W WO2009093683A1 WO 2009093683 A1 WO2009093683 A1 WO 2009093683A1 JP 2009051062 W JP2009051062 W JP 2009051062W WO 2009093683 A1 WO2009093683 A1 WO 2009093683A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- compound semiconductor
- film
- transparent conductive
- semiconductor light
- emitting element
- Prior art date
Links
- 239000004065 semiconductor Substances 0.000 title claims abstract description 361
- 150000001875 compounds Chemical class 0.000 title claims abstract description 208
- 238000004519 manufacturing process Methods 0.000 title claims description 42
- 239000013078 crystal Substances 0.000 claims abstract description 118
- 239000000758 substrate Substances 0.000 claims abstract description 45
- 239000000203 mixture Substances 0.000 claims abstract description 42
- 238000010438 heat treatment Methods 0.000 claims description 100
- 229910002601 GaN Inorganic materials 0.000 claims description 58
- 238000005530 etching Methods 0.000 claims description 43
- -1 gallium nitride compound Chemical class 0.000 claims description 23
- 238000010030 laminating Methods 0.000 claims description 21
- 239000000969 carrier Substances 0.000 claims description 14
- 238000004544 sputter deposition Methods 0.000 claims description 13
- 229910052738 indium Inorganic materials 0.000 claims description 6
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 claims description 6
- PJXISJQVUVHSOJ-UHFFFAOYSA-N indium(III) oxide Inorganic materials [O-2].[O-2].[O-2].[In+3].[In+3] PJXISJQVUVHSOJ-UHFFFAOYSA-N 0.000 abstract description 2
- 239000010408 film Substances 0.000 description 477
- 239000010410 layer Substances 0.000 description 180
- 238000000034 method Methods 0.000 description 79
- 238000002441 X-ray diffraction Methods 0.000 description 44
- 238000002834 transmittance Methods 0.000 description 37
- 238000012545 processing Methods 0.000 description 26
- 230000008569 process Effects 0.000 description 20
- 230000015572 biosynthetic process Effects 0.000 description 16
- JMASRVWKEDWRBT-UHFFFAOYSA-N Gallium nitride Chemical compound [Ga]#N JMASRVWKEDWRBT-UHFFFAOYSA-N 0.000 description 15
- 238000000605 extraction Methods 0.000 description 13
- 239000000463 material Substances 0.000 description 13
- 238000000137 annealing Methods 0.000 description 12
- 239000010931 gold Substances 0.000 description 12
- 239000012528 membrane Substances 0.000 description 11
- 239000012298 atmosphere Substances 0.000 description 10
- 229910052594 sapphire Inorganic materials 0.000 description 10
- 239000010980 sapphire Substances 0.000 description 10
- 239000007789 gas Substances 0.000 description 9
- 239000012299 nitrogen atmosphere Substances 0.000 description 9
- 238000000059 patterning Methods 0.000 description 9
- 239000000243 solution Substances 0.000 description 8
- 229910052751 metal Inorganic materials 0.000 description 7
- 239000002184 metal Substances 0.000 description 7
- 239000011241 protective layer Substances 0.000 description 7
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 6
- 238000005253 cladding Methods 0.000 description 6
- 238000002425 crystallisation Methods 0.000 description 6
- 230000008025 crystallization Effects 0.000 description 6
- 230000007423 decrease Effects 0.000 description 5
- 238000002474 experimental method Methods 0.000 description 5
- HZXMRANICFIONG-UHFFFAOYSA-N gallium phosphide Chemical compound [Ga]#P HZXMRANICFIONG-UHFFFAOYSA-N 0.000 description 5
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 4
- 229910002704 AlGaN Inorganic materials 0.000 description 4
- 229910005540 GaP Inorganic materials 0.000 description 4
- GYHNNYVSQQEPJS-UHFFFAOYSA-N Gallium Chemical compound [Ga] GYHNNYVSQQEPJS-UHFFFAOYSA-N 0.000 description 4
- 239000002253 acid Substances 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 229910052733 gallium Inorganic materials 0.000 description 4
- 229910052737 gold Inorganic materials 0.000 description 4
- 239000011777 magnesium Substances 0.000 description 4
- 229910052759 nickel Inorganic materials 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 238000000206 photolithography Methods 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 238000001039 wet etching Methods 0.000 description 4
- JBRZTFJDHDCESZ-UHFFFAOYSA-N AsGa Chemical compound [As]#[Ga] JBRZTFJDHDCESZ-UHFFFAOYSA-N 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000010894 electron beam technology Methods 0.000 description 3
- 238000001755 magnetron sputter deposition Methods 0.000 description 3
- 238000001451 molecular beam epitaxy Methods 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 3
- 238000007740 vapor deposition Methods 0.000 description 3
- 239000011701 zinc Substances 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 2
- 229910004298 SiO 2 Inorganic materials 0.000 description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 238000001312 dry etching Methods 0.000 description 2
- 230000005684 electric field Effects 0.000 description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 239000007774 positive electrode material Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000000523 sample Substances 0.000 description 2
- 229910010271 silicon carbide Inorganic materials 0.000 description 2
- JBQYATWDVHIOAR-UHFFFAOYSA-N tellanylidenegermanium Chemical compound [Te]=[Ge] JBQYATWDVHIOAR-UHFFFAOYSA-N 0.000 description 2
- VOITXYVAKOUIBA-UHFFFAOYSA-N triethylaluminium Chemical compound CC[Al](CC)CC VOITXYVAKOUIBA-UHFFFAOYSA-N 0.000 description 2
- RGGPNXQUMRMPRA-UHFFFAOYSA-N triethylgallium Chemical compound CC[Ga](CC)CC RGGPNXQUMRMPRA-UHFFFAOYSA-N 0.000 description 2
- OTRPZROOJRIMKW-UHFFFAOYSA-N triethylindigane Chemical compound CC[In](CC)CC OTRPZROOJRIMKW-UHFFFAOYSA-N 0.000 description 2
- JLTRXTDYQLMHGR-UHFFFAOYSA-N trimethylaluminium Chemical compound C[Al](C)C JLTRXTDYQLMHGR-UHFFFAOYSA-N 0.000 description 2
- XCZXGTMEAKBVPV-UHFFFAOYSA-N trimethylgallium Chemical compound C[Ga](C)C XCZXGTMEAKBVPV-UHFFFAOYSA-N 0.000 description 2
- IBEFSUTVZWZJEL-UHFFFAOYSA-N trimethylindium Chemical compound C[In](C)C IBEFSUTVZWZJEL-UHFFFAOYSA-N 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- IHGSAQHSAGRWNI-UHFFFAOYSA-N 1-(4-bromophenyl)-2,2,2-trifluoroethanone Chemical compound FC(F)(F)C(=O)C1=CC=C(Br)C=C1 IHGSAQHSAGRWNI-UHFFFAOYSA-N 0.000 description 1
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 1
- 229910010093 LiAlO Inorganic materials 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 229910020068 MgAl Inorganic materials 0.000 description 1
- 229910003902 SiCl 4 Inorganic materials 0.000 description 1
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 229910006404 SnO 2 Inorganic materials 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 239000006061 abrasive grain Substances 0.000 description 1
- MDPILPRLPQYEEN-UHFFFAOYSA-N aluminium arsenide Chemical compound [As]#[Al] MDPILPRLPQYEEN-UHFFFAOYSA-N 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- NWAIGJYBQQYSPW-UHFFFAOYSA-N azanylidyneindigane Chemical compound [In]#N NWAIGJYBQQYSPW-UHFFFAOYSA-N 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 239000012159 carrier gas Substances 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000002447 crystallographic data Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- PZPGRFITIJYNEJ-UHFFFAOYSA-N disilane Chemical compound [SiH3][SiH3] PZPGRFITIJYNEJ-UHFFFAOYSA-N 0.000 description 1
- 239000002019 doping agent Substances 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 238000000407 epitaxy Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 229910000078 germane Inorganic materials 0.000 description 1
- 150000002291 germanium compounds Chemical class 0.000 description 1
- 229910021478 group 5 element Inorganic materials 0.000 description 1
- 125000005842 heteroatom Chemical group 0.000 description 1
- 238000002248 hydride vapour-phase epitaxy Methods 0.000 description 1
- 150000004678 hydrides Chemical class 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- 229910003437 indium oxide Inorganic materials 0.000 description 1
- AMGQUBHHOARCQH-UHFFFAOYSA-N indium;oxotin Chemical compound [In].[Sn]=O AMGQUBHHOARCQH-UHFFFAOYSA-N 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 238000005224 laser annealing Methods 0.000 description 1
- 239000004973 liquid crystal related substance Substances 0.000 description 1
- 229910052749 magnesium 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
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 239000013081 microcrystal Substances 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- 229910052762 osmium Inorganic materials 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 238000010926 purge Methods 0.000 description 1
- 229910052702 rhenium Inorganic materials 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 229910052707 ruthenium Inorganic materials 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000011029 spinel Substances 0.000 description 1
- 229910052596 spinel Inorganic materials 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 238000000870 ultraviolet spectroscopy Methods 0.000 description 1
- 238000001771 vacuum deposition Methods 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 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
- H01L33/36—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
- H01L33/40—Materials therefor
- H01L33/42—Transparent materials
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
- H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
- H01L2224/42—Wire connectors; Manufacturing methods related thereto
- H01L2224/44—Structure, shape, material or disposition of the wire connectors prior to the connecting process
- H01L2224/45—Structure, shape, material or disposition of the wire connectors prior to the connecting process of an individual wire connector
- H01L2224/45001—Core members of the connector
- H01L2224/45099—Material
- H01L2224/451—Material with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof
- H01L2224/45138—Material with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof the principal constituent melting at a temperature of greater than or equal to 950°C and less than 1550°C
- H01L2224/45144—Gold (Au) as principal constituent
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
- H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
- H01L2224/42—Wire connectors; Manufacturing methods related thereto
- H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
- H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
- H01L2224/4805—Shape
- H01L2224/4809—Loop shape
- H01L2224/48091—Arched
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
- H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
- H01L2224/42—Wire connectors; Manufacturing methods related thereto
- H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
- H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
- H01L2224/481—Disposition
- H01L2224/48151—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
- H01L2224/48221—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
- H01L2224/48245—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being metallic
- H01L2224/48247—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being metallic connecting the wire to a bond pad of the item
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
- H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
- H01L2224/42—Wire connectors; Manufacturing methods related thereto
- H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
- H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
- H01L2224/481—Disposition
- H01L2224/48151—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
- H01L2224/48221—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
- H01L2224/48245—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being metallic
- H01L2224/48257—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being metallic connecting the wire to a die pad of the item
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
- H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
- H01L2224/42—Wire connectors; Manufacturing methods related thereto
- H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
- H01L2224/49—Structure, shape, material or disposition of the wire connectors after the connecting process of a plurality of wire connectors
- H01L2224/491—Disposition
- H01L2224/49105—Connecting at different heights
- H01L2224/49107—Connecting at different heights on the semiconductor or solid-state body
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/15—Details of package parts other than the semiconductor or other solid state devices to be connected
- H01L2924/181—Encapsulation
Definitions
- the present invention is suitable for light-emitting diodes (LEDs), laser diodes (LDs), electronic devices, etc., and is a compound semiconductor light-emitting device in which a compound semiconductor is laminated, a method for manufacturing the same, and a compound used in a compound semiconductor light-emitting device
- the present invention relates to a conductive light-transmitting electrode for a semiconductor light-emitting element, a lamp including a compound semiconductor light-emitting element, an electronic device in which the lamp is incorporated, and a mechanical device in which the electronic device is incorporated.
- a pn junction type light emitting diode is well known as an example of a compound semiconductor light emitting element.
- a GaP layer obtained by epitaxially growing a conductive gallium phosphide (GaP) single crystal on a substrate is used as a light emitting layer.
- gallium nitride compound such as a semiconductor layer of the light-emitting layer, the near-ultraviolet zone, the blue band or green band
- the short wavelength LED is known.
- the conductive n-type or p-type light emitting layer is formed using a conductive p-type or n-type gallium arsenide (GaAs) single crystal as a substrate. , Formed on the substrate.
- GaAs gallium arsenide
- a single crystal such as sapphire ( ⁇ -Al 2 O 3 single crystal) having electrical insulation is used as a substrate.
- cubic (3C crystal type) or hexagonal (4H or 6H crystal type) silicon carbide (SiC) is also used as a substrate.
- a light emitting element is formed by providing, for example, a first conductive type translucent electrode and a second conductive type electrode at predetermined positions on a semiconductor wafer in which a semiconductor layer is laminated on these substrates.
- a gallium nitride-based compound semiconductor light emitting device a sapphire single crystal, various oxides and III-V group compounds are used as a substrate, and an organic metal vapor phase chemical reaction method (MOCVD method) or molecule is formed thereon.
- MOCVD method organic metal vapor phase chemical reaction method
- a gallium nitride compound semiconductor is formed by a line epitaxy method (MBE method) or the like.
- MBE method line epitaxy method
- a translucent electrode is usually used as the positive electrode, and light is extracted through the positive electrode.
- the translucent electrode for example, a well-known conductive material such as one having a Ni / Au laminated structure or ITO is used.
- an oxide-based light-transmitting electrode mainly composed of In 2 O 3 , ZnO, or the like because it is a material having higher light-transmitting properties (for example, Patent Documents). 1).
- ITO used in the light-emitting element described in Patent Document 1 is the most frequently used material for a light-transmitting electrode.
- Such ITO is doped with, for example, 5 to 20% by mass of SnO 2. Further, by containing In 2 O 3 , a conductive oxide film having a low specific resistance of 2 ⁇ 10 ⁇ 4 ⁇ cm or less can be obtained.
- an amorphous IZO film is formed by a sputtering method. It has been proposed to perform an etching process relatively gently without using such a strong acid solution (see, for example, Patent Document 3). According to the method described in Patent Document 3, burrs, over-etching, and the like are less likely to occur compared to etching with strong acid, and microfabrication for improving light extraction efficiency can be easily performed.
- the amorphous IZO film is inferior in terms of translucency compared with the heat-treated ITO film, there is a problem that the light extraction efficiency is lowered and the light emission output of the light emitting element is lowered.
- the amorphous IZO film has a high contact resistance with the p-type GaN layer, there is a problem that the driving voltage of the light emitting element becomes high.
- it since it is amorphous, it has poor water resistance and chemical resistance, yield in the manufacturing process after the formation of the IZO film is reduced, and there is a possibility that problems such as reduction in device reliability may occur.
- Patent Document 4 a light-emitting element in which a crystallized IZO film is provided on a p-type semiconductor and used as a translucent electrode has been proposed (see, for example, Patent Document 4).
- the amorphous IZO film is annealed in a temperature range of 300 to 600 ° C. in nitrogen containing no oxygen, whereby the sheet resistance decreases as the annealing temperature increases ( (See paragraph 0036 of Patent Document 4), and when an IZO film is annealed at a temperature of 600 ° C. or higher, an X-ray peak composed of In 2 O 3 is mainly detected, so that the IZO film is crystallized. It is clear (see paragraph 0038 of Patent Document 4) and the like.
- Patent Document 4 discloses that when an IZO film is annealed at a temperature of 600 ° C., the transmittance in the ultraviolet region (wavelength: 350 to 420 nm) is 20 to 30% higher than that of an IZO film that has not been annealed. (Refer to paragraph 0040 of Patent Document 4), and in a light-emitting element having such an IZO film, the light emission distribution on the light-emitting surface has a characteristic of emitting light on the entire surface of the positive electrode, It is disclosed that the drive voltage Vf is 3.3 V and the light emission output Po is an element characteristic of 15 mW (see paragraph 0047 of Patent Document 4).
- In 2 O 3 As for the crystal structure of indium oxide (In 2 O 3 ), In 2 O 3 has two different crystal systems, a cubic system and a hexagonal system. In the case of a cubic system, normal pressure or normal pressure is used. It has been conventionally known that a bixbite crystal structure having a stable crystal phase under a lower pressure is disclosed in various literatures. In addition, a liquid crystal display panel using a polycrystalline indium tin oxide film having a cubic bixbyite crystal structure as described above has been proposed (see, for example, Patent Document 5).
- the present invention has been made in view of the above problems, and a compound semiconductor light emitting device having excellent light emission characteristics, a method for manufacturing the same, and a conductive light transmitting property for compound semiconductor light emitting devices having excellent light extraction efficiency and high productivity.
- An object is to provide an electrode.
- Another object of the present invention is to provide a lamp having the above-described compound semiconductor light-emitting element and having excellent light emission characteristics, an electronic device in which the lamp is incorporated, and a mechanical device in which the electronic device is incorporated. .
- the present invention relates to the following.
- An n-type semiconductor layer made of a compound semiconductor, a light emitting layer, and a p-type semiconductor layer are laminated in this order on a substrate, and further includes a positive electrode made of a conductive translucent electrode and a negative electrode made of a conductive electrode.
- a compound semiconductor light emitting device comprising: The compound semiconductor light-emitting element, wherein the conductive translucent electrode forming the positive electrode is a transparent conductive film containing crystals of a composition of In 2 O 3 having a hexagonal crystal structure.
- carrier mobility in the transparent conductive film is 30 cm 2 / V ⁇ sec or more.
- [3] The compound semiconductor light-emitting element according to item 1 or 2, wherein a carrier concentration of carriers in the transparent conductive film is in the range of 1 ⁇ 10 20 to 5 ⁇ 10 21 cm ⁇ 3 .
- [4] The compound semiconductor light-emitting element according to any one of [1] to [3], wherein a sheet resistance of the transparent conductive film is 50 ⁇ / sq or less.
- [5] The compound semiconductor light-emitting element according to any one of [1] to [4], wherein the thickness of the transparent conductive film is in the range of 35 nm to 10,000 nm (10 ⁇ m).
- the transparent conductive film is an IZO film, and the ZnO content in the IZO film is in the range of 1 to 20% by mass.
- Semiconductor light emitting device is any one of items 6 to 8, wherein the thickness of the transparent conductive film in the concave portion of the transparent conductive film is 1 ⁇ 2 or less of the thickness of the transparent conductive film in the convex portion.
- a method for producing a compound semiconductor light emitting device comprising at least each of the following steps (a) to (d): (A) A semiconductor layer forming step of fabricating a semiconductor wafer by laminating an n-type semiconductor layer made of a compound semiconductor, a light emitting layer, and a p-type semiconductor layer in this order on a substrate.
- C an etching step of etching the transparent conductive film into a predetermined shape; and
- D The etched transparent conductive film is subjected to heat treatment while controlling the holding time in a temperature range of 300 to 800 ° C., so that the transparent conductive film becomes In 2 O 3 having a hexagonal crystal structure.
- a heat treatment step including a crystal having a composition and controlling the mobility of carriers in the film to 30 cm 2 / V ⁇ sec or more.
- a compound semiconductor light-emitting element manufactured by the manufacturing method according to any one of items 14 to 19 above.
- a compound comprising a transparent conductive film including a crystal having a composition of In 2 O 3 having at least a hexagonal crystal structure, and having a carrier mobility of 30 cm 2 / V ⁇ sec or more in the film
- Conductive translucent electrode for semiconductor light emitting device [22] The conductive translucent electrode for a compound semiconductor light-emitting element according to [21], wherein the carrier mobility in the film is in the range of 30 to 100 cm 2 / V ⁇ sec.
- a lamp comprising the compound semiconductor light-emitting device according to any one of items 1 to 13 or 20 above.
- the present invention also relates to the following.
- an n-type semiconductor layer made of a compound semiconductor, a light emitting layer, and a p-type semiconductor layer are laminated in this order, and further provided with a positive electrode made of a conductive translucent electrode and a negative electrode made of a conductive electrode.
- a compound semiconductor light emitting device comprising: a conductive translucent electrode forming the positive electrode is a crystallized IZO film, and the IZO film includes a crystal having a composition of In 2 O 3 having a hexagonal crystal structure.
- a method for producing a compound semiconductor light-emitting element comprising at least the following steps (a) to (d): (A) A semiconductor layer forming step of fabricating a semiconductor wafer by laminating an n-type semiconductor layer made of a compound semiconductor, a light emitting layer, and a p-type semiconductor layer in this order on a substrate.
- C an etching step for etching the IZO film into a predetermined shape; and
- D The etched IZO film is subjected to heat treatment while controlling the holding time in a temperature range of 500 to 800 ° C., so that the IZO film has a composition of In 2 O 3 having a hexagonal crystal structure.
- a heat treatment step that includes crystals and controls the carrier mobility in the film to be 30 cm 2 / V ⁇ sec or more.
- the IZO film has a hexagonal crystal structure by performing heat treatment on the IZO film while controlling the holding time in a temperature range of 500 to 800 ° C. 44.
- the compound semiconductor light-emitting element according to item 43 including a crystal having a composition of In 2 O 3 and having carrier mobility in the film controlled to be in a range of 30 to 100 cm 2 / V ⁇ sec. Manufacturing method.
- the method for producing a compound semiconductor light-emitting element according to [43] or [44], wherein the conductive translucent electrode laminating step (b) includes laminating the IZO film by a sputtering method.
- a compound semiconductor light-emitting element manufactured by the manufacturing method according to any one of items 43 to 47.
- a compound semiconductor comprising an IZO film including a crystal having a composition of In 2 O 3 having at least a hexagonal crystal structure, and carrier mobility in the film being 30 cm 2 / V ⁇ sec or more Conductive translucent electrode for light emitting element.
- a lamp comprising the compound semiconductor light-emitting device according to any one of items 27 to 42 or 48.
- each layer made of a compound semiconductor is laminated on a substrate, and further includes a positive electrode made of a conductive translucent electrode and a negative electrode made of a conductive electrode, and the conductive transparent electrode forming the positive electrode.
- the photoconductive electrode is a transparent conductive film including a crystal having a composition of In 2 O 3 having a hexagonal crystal structure, a conductive translucent electrode having a particularly high light transmittance in the visible to ultraviolet region can be obtained.
- the light extraction characteristics of the light emitting element are improved. Thereby, a compound semiconductor light emitting device having particularly excellent light emission output characteristics can be realized.
- each layer made of a compound semiconductor is laminated on a substrate, and further includes a positive electrode made of a conductive type translucent electrode and a negative electrode made of a conductive type electrode.
- the conductive electrode is composed of a crystallized IZO film, and the IZO film includes a crystal having a composition of In 2 O 3 having a hexagonal crystal structure. Therefore, the conductive light transmission having a particularly high light transmittance in the visible to ultraviolet region.
- the light extraction characteristics of the light-emitting element can be improved. Thereby, a compound semiconductor light emitting device having particularly excellent light emission output characteristics can be realized. Furthermore, by adopting a configuration in which the carrier mobility in the IZO film forming the conductive translucent electrode is controlled to 30 cm 2 / V ⁇ sec or more, a low-resistance positive electrode can be obtained, and the driving voltage can be reduced. A low compound semiconductor light emitting device can be realized.
- Each of the transparent conductive film includes a crystal having a composition of In 2 O 3 having a hexagonal crystal structure, and the carrier mobility in the film is controlled to a characteristic of 30 cm 2 / V ⁇ sec or more.
- the method includes a process, it is provided with a conductive translucent electrode having particularly excellent light transmittance in the visible to ultraviolet region, has a particularly excellent light emission output characteristic, and low
- the compounds of the dynamic voltage semiconductor light-emitting device can be obtained.
- a semiconductor layer forming step of stacking each layer made of a compound semiconductor on a substrate to produce a semiconductor wafer, and an amorphous IZO film on the p-type semiconductor layer By conducting a heat treatment while controlling the holding time in a temperature range of 500 to 800 ° C.
- the transparent electrode includes at least a crystal having a composition of In 2 O 3 having a hexagonal crystal structure, and the carrier mobility in the film is high. Since the configuration is 30 cm 2 / V ⁇ sec or more, an electrode having low resistance and excellent translucency can be obtained.
- the translucent electrode for a compound semiconductor light-emitting device of the present invention it is composed of an IZO film including a crystal having a composition of In 2 O 3 having at least a hexagonal crystal structure, and the carrier mobility in the film is 30 cm. Since the configuration is 2 / V ⁇ sec or more, an electrode having low resistance and excellent translucency can be obtained.
- the lamp of the present invention since the semiconductor compound light emitting device of the present invention is provided, the light emitting characteristics are excellent. Further, according to the electronic device of the present invention, the lamp of the present invention is incorporated, so that the device characteristics are excellent. Also, according to the mechanical device of the present invention, the electronic device of the present invention is Since it is incorporated, it has excellent device characteristics.
- SYMBOLS 1 Compound semiconductor light emitting element (light emitting element, gallium nitride type compound semiconductor light emitting element) 10, 20 ... Semiconductor wafer, 11, 21 ... Substrate, 12 ... N type semiconductor layer, 13 ... Light emitting layer, 14 ... P type semiconductor layer , 15... Positive electrode (conductive translucent electrode: IZO film), 16... Positive electrode bonding pad, 17... Negative electrode, 22... GaN underlayer (n-type semiconductor layer), 23. , 24... N-type AlGaN cladding layer (n-type semiconductor layer), 25... Emission layer, 26... P-type AlGaN cladding layer (p-type semiconductor layer), 27. ...lamp.
- Compound semiconductor light emitting element light emitting element, gallium nitride type compound semiconductor light emitting element
- 10 Semiconductor wafer, 11, 21 ... Substrate, 12 ... N type semiconductor layer, 13 ... Light emitting layer, 14 ... P type semiconductor layer , 15... Positive electrode (conductive
- FIG. 1 is a cross-sectional view showing a face-up type compound semiconductor light emitting device of this embodiment
- FIG. 2 is a plan view of the compound semiconductor light emitting device shown in FIG. 1
- FIG. 3 is a gallium nitride compound having a laminated structure.
- FIG. 4 is a schematic view showing a lamp in which the compound semiconductor light emitting device shown in FIG. 1 is used, and FIGS.
- 5A, 5B and 6 are projections and depressions on the positive electrode provided in the compound semiconductor light emitting device. It is the schematic which shows the example in which was formed.
- the drawings referred to in the following description are drawings for explaining the compound semiconductor light-emitting element and the manufacturing method thereof, the conductive translucent electrode for the compound semiconductor light-emitting element, the lamp, the electronic device, and the mechanical device of the present embodiment. Thus, the size, thickness, dimensions, and the like of each part shown in the drawing are different from the dimensional relationship of an actual compound semiconductor light emitting element.
- a compound semiconductor constituting the light emitting element in the present invention for example, a general formula Al X Ga Y In ZN 1-a M a (0 ⁇ X ⁇ 1, 0 ⁇ ) provided on a sapphire substrate, silicon carbide, silicon substrate or the like.
- Y ⁇ 1, 0 ⁇ Z ⁇ 1, and X + Y + Z 1, the symbol M represents a Group V element different from nitrogen, and 0 ⁇ a ⁇ 1)
- a system light emitting element is mentioned.
- a GaP light emitting element provided on a GaP substrate is also applied.
- the structure of a compound semiconductor constituting a known light emitting element is also applied.
- a gallium nitride-based compound semiconductor light emitting element is preferably applied as an example of a group III nitride semiconductor.
- the compound semiconductor layer applied in the above light-emitting element is stacked over a substrate selected based on a target function.
- a substrate selected based on a target function.
- an n-type semiconductor layer and a p-type semiconductor layer are arranged on the first and second main surfaces, that is, both surfaces of the light emitting layer.
- electrodes are respectively disposed on the n-type semiconductor layer and the p-type semiconductor layer.
- a conductive translucent electrode having high translucency is used particularly on the light emission side.
- the conductive translucent electrode used on the light emission side is a transparent conductive film containing crystals of a composition of In 2 O 3 having a hexagonal crystal structure.
- the conductive translucent electrode used on the light emission side is made of a crystallized IZO film and includes crystals of a composition of In 2 O 3 having a hexagonal crystal structure.
- the present invention is not limited to gallium nitride-based compound semiconductor light-emitting elements, but can be applied to light-emitting elements using the various compound semiconductors described above.
- the compound semiconductor light-emitting element (hereinafter sometimes abbreviated as a light-emitting element) 1 of the present embodiment is formed on a substrate 11 with a compound semiconductor (hereinafter sometimes abbreviated as a semiconductor) as in the example shown in FIG.
- the n-type semiconductor layer 12, the light emitting layer 13, and the p-type semiconductor layer 14 are stacked in this order, and further include a positive electrode 15 made of a conductive translucent electrode and a negative electrode made of a conductive electrode 17.
- the conductive translucent electrode forming the positive electrode 15 is composed of a transparent conductive film containing crystals having a composition of In 2 O 3 having a hexagonal crystal structure.
- the conductive translucent electrode forming the positive electrode 15 can be made of a crystallized IZO film, and the IZO film can contain crystals of In 2 O 3 having a hexagonal crystal structure.
- a positive electrode bonding pad 16 made of a conductive type electrode or material is provided on a positive electrode 15 made of a conductive type translucent electrode.
- the laminated structure of the light emitting device 1 of the present embodiment will be described.
- the material of the substrate 11 includes sapphire single crystal (Al 2 O 3 ; A plane, C plane, M plane, R plane), spinel single crystal (MgAl 2 O 4 ), ZnO single crystal, LiAlO 2 single crystal, LiGaO 2.
- Known substrate materials such as single crystals, oxide single crystals such as MgO single crystals, Si single crystals, SiC single crystals, GaAs single crystals, AlN single crystals, GaN single crystals, and ZrB 2 boride single crystals are not limited. Can be used.
- the plane orientation of the substrate is not particularly limited. Moreover, a just board
- the n-type semiconductor layer 12 As the n-type semiconductor layer 12, the light emitting layer 13, and the p-type semiconductor layer 14, those having various structures are well known, and these well-known materials can be used without any limitation.
- the p-type semiconductor layer 14 may be one having a general carrier concentration. Even for a p-type semiconductor layer having a relatively low carrier concentration, for example, about 1 ⁇ 10 17 cm ⁇ 3 , The positive electrode 15 used in the present invention and made of a transparent conductive film, the details of which will be described later, can be applied.
- Examples of the compound semiconductor used for each semiconductor layer include a gallium nitride-based compound semiconductor.
- a gallium nitride-based compound semiconductor As the gallium nitride-based compound semiconductor, a general formula Al x In y Ga 1-xy N (0 ⁇ x ⁇ Semiconductors having various compositions represented by 1,0 ⁇ y ⁇ 1,0 ⁇ x + y ⁇ 1) are well known, and the gallium nitride-based compound semiconductor constituting the n-type semiconductor layer, the light-emitting layer, and the p-type semiconductor layer in the present invention In addition, semiconductors of various compositions represented by the general formula Al x In y Ga 1-xy N (0 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 1, 0 ⁇ x + y ⁇ 1) can be used without any limitation.
- a semiconductor wafer in which the gallium nitride compound semiconductor as described above is laminated on a substrate it is made of sapphire like a gallium nitride compound semiconductor wafer 20 having a laminated structure as shown in FIG.
- a buffer layer (not shown) made of AlN is stacked on the substrate 21, and sequentially, a GaN foundation layer 22, an n-type GaN contact layer 23, an n-type AlGaN cladding layer 24, a light emitting layer 25 made of InGaN, and a p-type AlGaN cladding.
- the layer 26 and the p-type GaN contact layer 27 are stacked.
- the conductive translucent electrode forming the positive electrode 15 of the present embodiment is composed of a transparent conductive film containing crystals of a composition of In 2 O 3 having a hexagonal crystal structure.
- the transparent conductive film is preferably any one of an IZO (indium / zinc based oxide) film, an ITO (indium / tin based oxide) film, and an IGO (indium / gallium based oxide) film.
- the conductive translucent electrode constituting the positive electrode 15 of the present embodiment is made of a crystallized IZO (indium / zinc-based oxide) film, and the IZO film is made of In 2 O 3 having a hexagonal crystal structure. It may include crystals of the composition.
- IZO indium / zinc-based oxide
- the carrier mobility in the film is preferably 30 cm 2 / V ⁇ sec or more.
- the carrier mobility is more preferably 35 cm 2 / V ⁇ sec or more, and most preferably 38 cm 2 / V ⁇ sec or more.
- the mobility of carriers in the transparent conductive film is preferably in the range of 30 to 100 cm 2 / V ⁇ sec, more preferably in the range of 35 to 90 cm 2 / V ⁇ sec, and 38 Most preferred is a range of ⁇ 90 cm 2 / V ⁇ sec.
- the positive electrode (conductivity type translucent electrode) 15 has a structure in which the carrier mobility in the film is controlled to be in the above range, and thus has a particularly excellent light transmittance in the visible to ultraviolet region. As a result, the light emission output characteristics of the light emitting element 1 are improved.
- the mobility described in the present invention is an amount obtained by dividing the moving speed by the strength of an electric field when a charged particle, that is, a carrier moves under an electric field.
- the carrier concentration of the transparent conductive film forming the positive electrode 15, for example, the IZO film is not particularly limited, but is preferably in the range of 1 ⁇ 10 20 to 5 ⁇ 10 21 cm ⁇ 3 , and 1 ⁇ 10 20 to 1 A range of ⁇ 10 21 cm ⁇ 3 is more preferable.
- the sheet resistance of the transparent conductive film forming the positive electrode 15 is preferably 50 ⁇ / sq or less, and more preferably 20 ⁇ / sq or less, in order to diffuse current efficiently.
- the transparent conductive film forming the positive electrode 15 it is preferable to use a material having a composition with the lowest specific resistance for the transparent conductive film forming the positive electrode 15, for example, an IZO film.
- the ZnO concentration in the IZO film is preferably 1 to 20% by mass, more preferably 5 to 15% by mass, Moreover, it is most preferable that it is about 10 mass%.
- Crystals having a composition of In 2 O 3 are known to have two types of structures, a cubic structure having a bixbite structure and a hexagonal structure.
- the transparent conductive film used as the positive electrode 15 may include not only hexagonal In 2 O 3 but also cubic In 2 O 3 .
- the IZO film used as the positive electrode 15 in the present invention can also be configured to include hexagonal In 2 O 3 or cubic In 2 O 3 .
- a transparent conductive film used as the positive electrode 15 in the present invention for example, an IZO film, is an amorphous transparent conductive film that is a composite oxide of In 2 O 3 and a metal oxide contained in the transparent conductive film.
- the crystallinity mainly includes a hexagonal In 2 O 3 crystal, and the carrier mobility in the film is 30 cm 2 / V ⁇ sec or more. It is obtained as a transparent conductive film having a high thickness.
- an amorphous transparent conductive film for example, an IZO film
- an amorphous transparent conductive film is mainly composed of In 2 having a hexagonal structure by optimizing conditions (temperature, holding time, etc.) in a heat treatment step to be described in detail later.
- the composition can be controlled to contain a large amount of O 3 crystals, and by using such a transparent conductive film for the positive electrode (conductive-type translucent electrode) of the compound semiconductor light-emitting element, the light-emitting characteristics of the light-emitting element are significantly improved. (Refer to the column of the manufacturing method and Example mentioned later).
- the transparent conductive film for example, IZO film
- the transparent conductive film is changed from a hexagonal crystal structure to a bixbite (cubic crystal) structure when the heating conditions are not suitable. It has been clarified that transition occurs, resulting in an increase in sheet resistance, resulting in a decrease in characteristics as a conductive translucent electrode for a compound semiconductor light emitting device.
- the transparent conductive film is made of an IZO film
- the IZO film was also found to be nonuniform in the IZO composition due to Zn migration depending on the heat treatment conditions.
- the positive electrode provided in the compound semiconductor light-emitting device according to the present invention has the above-described configuration, and the conductivity type translucency having excellent light transmittance by appropriately controlling the conditions of the heat treatment process described in detail later. It becomes an electrode.
- the film thickness of the transparent conductive film forming the positive electrode 15, for example, the IZO film is preferably in the range of 35 nm to 10000 nm (10 ⁇ m) at which low sheet resistance and high light transmittance can be obtained. Furthermore, from the viewpoint of production cost, the film thickness of the positive electrode 15 is preferably 1000 nm (1 ⁇ m) or less.
- the surface of the transparent conductive film forming the positive electrode 15, for example, the IZO film is processed to have a concavo-convex shape as shown in FIGS. 5A, 5B and 6 by a method described in detail later. Although details of such unevenness processing will be described later, by making the surface of the transparent conductive film uneven, it is possible to improve the light transmittance of the positive electrode and improve the light emission output of the light emitting element. It becomes possible.
- a metal layer (not shown).
- the metal layer is arranged between the positive electrode 15 and the p-type semiconductor layer 14
- the driving voltage of the light emitting element can be reduced, while the light transmittance of the positive electrode is reduced. In some cases, the light emission output of the light emitting element is lowered.
- whether or not a metal layer or the like is arranged between the positive electrode and the p-type semiconductor layer is appropriately determined in consideration of the balance between the driving voltage and the output according to the use of the light emitting element. It is preferable.
- the metal layer is made of Ni, Ni oxide, Pt, Pd, Ru, Rh, Re, Os, or the like. Is preferably used.
- the positive electrode provided in the compound semiconductor light-emitting element according to the present invention that is, the conductive light-transmitting electrode for compound semiconductor light-emitting element, has excellent light-transmitting characteristics and light-extracting characteristics due to the above configuration.
- the negative electrode 17 is obtained by heat-treating a transparent conductive film that constitutes the positive electrode 15, for example, an IZO film (see the heat treatment step described later), and then, as shown in FIGS. 1 and 2, the p-type semiconductor layer 14, the light-emitting layer 13, and n A part of the n-type semiconductor layer 12 is removed by etching to expose a part of the n-type semiconductor layer 12, and a conventionally known negative electrode 17 made of, for example, Ti / Au is provided on the exposed n-type semiconductor layer 12. .
- negative electrodes having various compositions and structures are well known, and these known negative electrodes can be used without any limitation.
- a positive electrode bonding pad 16 for electrically connecting to a circuit board, a lead frame, or the like outside the light emitting element is formed on at least a part of the transparent conductive film forming the positive electrode (conductive translucent electrode) 15, for example, the IZO film.
- the positive electrode bonding pad 16 various structures using materials such as Au, Al, Ni, and Cu are well known, and those with known materials and structures can be used without any limitation.
- the thickness of the positive electrode bonding pad 16 is preferably in the range of 100 to 1000 nm. Further, in view of the characteristics of the bonding pad, the larger the thickness, the higher the bondability. Therefore, the thickness of the positive electrode bonding pad 16 is more preferably 300 nm or more. Furthermore, the thickness is preferably 500 nm or less from the viewpoint of manufacturing cost.
- a protective layer (not shown) is provided on the positive electrode 15.
- a material having excellent translucency in order to cover the entire region on the positive electrode 15 except the region where the positive electrode bonding pad 16 is formed.
- it is preferably made of an insulating material. For example, SiO 2 , Al 2 O 3 or the like may be used.
- the thickness of the protective layer may be any film thickness that can prevent oxidation of the positive electrode 15 made of a transparent conductive film, for example, an IZO film, and can maintain translucency. Specifically, for example, It is preferably in the range of 20 nm to 500 nm.
- the layers made of the compound semiconductor are stacked on the substrate 11, and the positive electrode 15 made of the conductive translucent electrode and the negative electrode 17 made of the conductive electrode.
- the conductive translucent electrode forming the positive electrode 15 is made of a transparent conductive film containing a crystal having a composition of In 2 O 3 having a hexagonal crystal structure, and therefore has a particularly high light transmittance in the visible to ultraviolet region. It can be set as a translucent electrode and the light extraction characteristic of the light emitting element 1 is improved.
- each layer made of a compound semiconductor is laminated on the substrate 11, and further includes a positive electrode 15 made of a conductive translucent electrode and a negative electrode 17 made of a conductive electrode.
- the conductive translucent electrode 15 is made of a crystallized IZO film, and the IZO film includes a crystal having a composition of In 2 O 3 having a hexagonal crystal structure. Therefore, the light extraction characteristics of the light-emitting element 1 can be improved. Thereby, the compound semiconductor light emitting device 1 having particularly excellent light emission output characteristics can be realized.
- the carrier mobility in the transparent conductive film forming the positive electrode (conductivity type translucent electrode) 15, for example, in the IZO film to 30 cm 2 / V ⁇ sec or more,
- the compound semiconductor light emitting device 1 having a low resistance and a low driving voltage can be realized.
- the compound semiconductor light emitting device cathode (compound semiconductor light-emitting device for light-transmitting electrode) 15 used in the first embodiment a transparent conductive film containing crystals of In 2 O 3 having a composition having a hexagonal crystal structure
- the carrier mobility in the film is 30 cm 2 / V ⁇ sec or more, excellent translucency and low resistance can be obtained.
- the positive electrode (translucent electrode for compound semiconductor light emitting device) 15 used in the compound semiconductor light emitting device 1 of the present embodiment the positive electrode (transparent electrode for compound semiconductor light emitting device) 15 is composed of an IZO film containing crystals of In 2 O 3 having a hexagonal crystal structure.
- the mobility of carriers in the film is 30 cm 2 / V ⁇ sec or more, excellent translucency and low resistance can be obtained.
- the method for manufacturing a compound semiconductor light emitting device of this embodiment is a method for manufacturing the light emitting device 1 as illustrated in FIGS. 1 and 2 by a method including at least the following steps (a) to (d). .
- C an etching process for etching a transparent conductive film, such as an IZO film, into a predetermined shape;
- D An etched transparent conductive film, for example, an IZO film, is subjected to heat treatment while controlling the holding time in a temperature range of 500 to 800 ° C., so that the transparent conductive film, for example, the IZO film has a hexagonal structure.
- the n-type semiconductor layer 12, the light emitting layer 13, and the p-type semiconductor layer 14 made of a compound semiconductor are arranged on the substrate 11 in this order.
- the semiconductor wafer 10 is manufactured by laminating. Specifically, a buffer layer (not shown) made of, for example, AlN is formed on the substrate 11, and then a gallium nitride compound semiconductor is epitaxially grown on the buffer layer to thereby form the n-type semiconductor layer 12 and the light emitting layer 13. And the p-type semiconductor layer 14 are sequentially stacked to form a semiconductor layer.
- the growth method of the above gallium nitride compound semiconductor is not particularly limited, and gallium nitride compound semiconductor such as MOCVD (metal organic chemical vapor deposition), HVPE (hydride vapor deposition), MBE (molecular beam epitaxy), etc. All methods known to grow can be applied.
- MOCVD metal organic chemical vapor deposition
- HVPE hydrogen vapor deposition
- MBE molecular beam epitaxy
- All methods known to grow can be applied.
- the MOCVD method can be suitably used from the viewpoint of film thickness controllability and mass productivity.
- H 2 hydrogen
- N 2 nitrogen
- trimethyl gallium (TMG) or triethyl gallium (TEG) as a Ga source
- trimethyl aluminum (TMA) or triethyl aluminum (TEA) as an Al source
- Trimethylindium (TMI) or triethylindium (TEI) is used as the source
- ammonia (NH 3 ), hydrazine (N 2 H 4 ), or the like is used as the N source.
- n-type semiconductor layer 12 monosilane (SiH 4 ) or disilane (Si 2 H 6 ) is used as a Si raw material, germane (GeH 4 ) or an organic germanium compound is used as a Ge raw material, and a p-type semiconductor is used.
- a p-type semiconductor is used for the layer.
- biscyclopentadienyl magnesium (Cp 2 Mg) or bisethylcyclopentadienyl magnesium ((EtCp) 2 Mg) can be used as the Mg raw material.
- Conductive translucent electrode (positive electrode: transparent conductive film, for example, IZO film) formation process Next, in the conductive type translucent electrode forming step shown in (b) above, a positive electrode made of a transparent conductive film, for example, an IZO film, is formed on the p-type semiconductor layer 14 of the semiconductor layer formed in the semiconductor layer forming step. Conductive translucent electrode) 15 is formed.
- an amorphous transparent conductive film for example, an IZO film is formed over the entire upper surface of the p-type semiconductor layer 14.
- a method for forming a transparent conductive film for example, an IZO film
- any known method used for forming a thin film can be used as long as it can form an amorphous transparent conductive film.
- a film can be formed using a method such as a sputtering method (sputtering method) or a vacuum vapor deposition method.
- sputtering method sputtering method
- a vacuum vapor deposition method a vacuum vapor deposition method.
- using the sputtering method can cause particles or dust generated during film formation compared to the vacuum vapor deposition method. It is preferable from the point that there are few.
- an IZO film is formed as a transparent conductive film using a sputtering method
- an In 2 O 3 target and a ZnO target can be formed by revolving film formation using an RF magnetron sputtering method.
- the discharge output of sputtering is preferably 1000 W or less.
- the amorphous transparent conductive film, for example, an IZO film, formed in the conductive translucent electrode forming step is etched into a predetermined shape.
- a transparent conductive film, for example, an IZO film is patterned by using a well-known photolithography method and etching method, thereby removing the transparent conductive film in a region excluding the formation region of the positive electrode 15 on the p-type semiconductor layer 14. Then, as shown in FIG. 2, the transparent conductive film is formed only in the formation region of the positive electrode 15.
- the etching process for patterning the transparent conductive film is preferably performed before the heat treatment process described later.
- a transparent conductive film that has been in an amorphous state such as an IZO film
- a transparent conductive film for example, an IZO film
- the transparent conductive film (for example, IZO film) before heat treatment is in an amorphous state, it can be easily etched with high accuracy using a known etching solution.
- etching can be performed at a rate of about 40 nm / min, and burrs and overetching hardly occur.
- the amorphous transparent conductive film for example, the IZO film, may be etched using a dry etching apparatus. At this time, Cl 2 , SiCl 4 , BCl 3 or the like can be used as an etching gas.
- the surface of the transparent conductive film, for example, an IZO film is formed by using the above-described photolithography method and etching method as shown in FIGS. 5A, 5B, and 6. It is possible to form an uneven process. For example, in the case of an IZO film, when an ITO-07N etching solution is used, irregularities with a depth of 40 nm can be formed with an etching time of 1 minute. As shown in FIG. 5A, FIG. 5B, and FIG.
- the light transmittance of the positive electrode is improved by performing uneven processing on the surface of the transparent conductive film, for example, the surface of the IZO film, using the etching method, and the light emission output of the light emitting element is improved. Can be made.
- the reasons why the light emission output is improved by uneven processing on the surface of the transparent conductive film, for example, the surface of the IZO film, are as follows. 1. Improvement of light transmittance by thinning the positive electrode. 2. Increase of light extraction area (transparent conductive film surface area) by uneven processing; Reduction of total reflection on the surface of the positive electrode can be considered.
- the shape of the uneven processing on the surface of the transparent conductive film for example, the surface of the IZO film has an effect of improving the output for any of the above reasons for the reasons 1 to 3 above. Since it can be made larger, it is more preferable to have a dot shape as shown in FIGS. 5A, 5B, and 6.
- the conductive translucent electrode has a lower sheet resistance as the film thickness is increased, and the current flowing through the film is likely to diffuse to the entire area of the electrode. It is preferable to form in an uneven shape. For this reason, as a dot shape, it is more preferable to use a shape having independent concave portions as shown in FIGS. 5A and 5B than a shape having independent convex portions as shown in FIG. In addition, if the area of the concave portion is 1/4 or less of the area of the convex portion, the light output improvement effect is small, and if it is 3/4 or more, the current is difficult to diffuse and the drive voltage increases. Is preferably in the range of 1 ⁇ 4 to 3 ⁇ 4 of the area of the convex portion.
- the film thickness of the concave portion is 1 ⁇ 2 or less of the film thickness of the convex portion.
- the transparent conductive film in the concave portion for example, the IZO film is completely etched, that is, when the thickness of the concave portion of the transparent conductive film, for example, the IZO film is 0 nm, the transparent conductive film, for example, the IZO film is not interposed.
- light from the semiconductor layer p-type semiconductor layer side
- the patterning of the transparent conductive film and the uneven processing can be performed at the same time, and the process time can be shortened.
- the contact area between the transparent conductive film and the p-type semiconductor layer is reduced, so that the driving voltage of the light emitting element may be increased. Therefore, only when the light emission output is prioritized over the driving voltage of the light emitting element, the film thickness of the recess is 0 nm, that is, a transparent conductive film obtained by completely etching the transparent conductive film in the recess may be used.
- a photolithography method can be used without any limitation for the above-described concavo-convex processing.
- the g-line or i-line is used. It is preferable to form smaller irregularities using a stepper, a nanoimprint apparatus, a laser exposure apparatus, or an EB (electron beam) exposure apparatus.
- heat treatment process Next, in the heat treatment step shown in (d) above, heat treatment is performed on the transparent conductive film patterned in the etching step. Specifically, the patterned transparent conductive film is subjected to a heat treatment while controlling the holding time in a temperature range of 300 to 800 ° C., so that the transparent conductive film has a composition of In 2 O 3 having a hexagonal crystal structure. And the carrier mobility in the film is controlled to a characteristic of 30 cm 2 / V ⁇ sec or more to form the positive electrode 15. In the heat treatment step shown in (d) above, the surface of the IZO film patterned in the etching step may be heat treated.
- the IZO film is converted into a crystal having a composition of In 2 O 3 having a hexagonal crystal structure.
- the carrier mobility in the film is controlled to a characteristic of 30 cm 2 / V ⁇ sec or more to obtain a positive electrode 15.
- the transparent conductive film in an amorphous state becomes a crystallized transparent conductive film by performing heat treatment in a temperature range of 300 to 800 ° C., for example.
- the light emission wavelength of the light emitting element for example, the light transmittance from the visible light region to the ultraviolet light region, and in particular, the wavelength of 380 nm to 500 nm.
- the light transmittance is greatly improved in the region.
- the amorphous IZO film becomes a crystallized IZO film surface by performing a heat treatment in a temperature range of 500 to 800 ° C., for example.
- the IZO film by crystallizing the IZO film, it becomes possible to improve the light emission wavelength of the light emitting element, for example, the light transmittance from the visible light region to the ultraviolet light region, and in particular, the wavelength region of 380 nm to 500 nm.
- the light transmittance is greatly improved.
- a crystallized transparent conductive film for example, an IZO film, is difficult to etch, and thus the heat treatment step is preferably performed after the etching step.
- the heat treatment of the transparent conductive film is preferably performed in an atmosphere that does not contain O 2.
- the atmosphere that does not contain O 2 include inert gas atmospheres such as N 2 atmospheres and non-N 2 atmospheres.
- An atmosphere of a mixed gas of active gas and H 2 can be given, and an N 2 atmosphere or a mixed gas atmosphere of N 2 and H 2 is preferable.
- the IZO film is heat-treated in an N 2 atmosphere, a mixed gas atmosphere of N 2 and H 2 , or in a vacuum. And the sheet resistance of the IZO film can be effectively reduced.
- a transparent conductive film for example, an IZO film
- the ratio of H 2 and N 2 in the atmosphere is preferably in the range of 100: 1 to 1: 100.
- the sheet resistance of the transparent conductive film increases.
- the sheet resistance of the transparent conductive film for example, the IZO film
- the sheet resistance of the transparent conductive film is increased because oxygen vacancies in the transparent conductive film, for example, the IZO film are decreased.
- the reason why the transparent conductive film, for example, the IZO film shows conductivity is that oxygen vacancies are present in the transparent conductive film, for example, the IZO film, thereby generating electrons serving as carriers. It is considered that the oxygen vacancies that are generation sources are reduced by the heat treatment, whereby the carrier concentration of the transparent conductive film, for example, the IZO film is lowered, and the sheet resistance is increased.
- the heat treatment temperature of the transparent conductive film is preferably in the range of 300 to 800 ° C.
- the transparent conductive film may not be sufficiently crystallized, and the transparent conductive film, for example, the IZO film may not have a sufficiently high light transmittance.
- the transparent conductive film may be crystallized but may not be a film having a sufficiently high light transmittance.
- the semiconductor layer under the transparent conductive film may be deteriorated.
- the heat treatment temperature of the IZO film is preferably in the range of 500 to 800 ° C.
- the IZO film may not be sufficiently crystallized, and the IZO film may not have a sufficiently high light transmittance.
- the heat treatment of the IZO film is performed at a temperature higher than 800 ° C., the IZO film may be crystallized but may not be a film having a sufficiently high light transmittance.
- heat treatment is performed at a temperature exceeding 800 ° C., the semiconductor layer under the IZO film may be deteriorated.
- the crystallized transparent conductive film for example, an IZO film
- the crystallized transparent conductive film for example, an IZO film
- the crystallized transparent conductive film preferably contains an In 2 O 3 crystal having a hexagonal crystal structure.
- the driving voltage of the light emitting element is lowered due to the inclusion of the hexagonal structure In 2 O 3 crystal in the transparent conductive film, for example, the IZO film is not clear, but the hexagonal structure In 2 O 3 crystal is included. This is considered to be because the contact resistance at the contact interface between the positive electrode made of a transparent conductive film, for example, an IZO film, and the p-type semiconductor layer is reduced.
- an IZO film includes In 2 O 3 crystals having a hexagonal structure
- the conditions vary depending on the film forming method and composition of the transparent conductive film, for example, the IZO film.
- the crystallization temperature is lowered when the zinc (Zn) concentration in the IZO film is decreased. Therefore, an In 2 O 3 crystal having a hexagonal structure is formed by a lower temperature heat treatment. It can be set as the IZO film
- the transparent conductive film for example, an IZO film is crystallized by a heat treatment process, but the present invention is not limited to this, and the transparent conductive film, for example, an IZO film can be crystallized. Any method may be used as long as it is present.
- a transparent conductive film such as an IZO film may be crystallized using a method using an RTA annealing furnace, a laser annealing method, an electron beam irradiation method, or the like.
- a transparent conductive film crystallized by heat treatment such as an IZO film
- a transparent conductive film crystallized by heat treatment has better adhesion to the p-type semiconductor layer 14 and the positive electrode bonding pad 16 than an amorphous transparent conductive film such as an IZO film. It is possible to prevent a decrease in yield due to peeling during the manufacturing process of the light emitting element.
- a crystallized transparent conductive film, such as an IZO film has less reaction with moisture in the air and is superior in chemical resistance such as acid compared to an amorphous transparent conductive film, such as an IZO film. There is an advantage that the characteristic deterioration in the durability test is small.
- a transparent conductive film such as an IZO film
- the transparent conductive film such as an IZO film
- the mobility of carriers in the film is controlled to be in the range of 30 cm 2 / V ⁇ sec or more, more preferably in the range of 30 to 100 cm 2 / V ⁇ sec. It is possible to form the positive electrode 15 having extremely excellent light transmittance in the light region and having low resistance.
- a positive electrode bonding pad 16 is formed on a transparent conductive film that forms the positive electrode (conductive translucent electrode) 15, for example, an IZO film.
- a material such as Au, Al, Ni and Cu is used for at least a part of the transparent conductive film (positive electrode 15), for example, the IZO film (positive electrode 15).
- the positive electrode bonding pad 16 is formed by a conventionally known method.
- a protective layer (not shown) is formed on the positive electrode 15 to prevent oxidation of the transparent conductive film that forms the positive electrode 15, for example, an IZO film.
- a material having translucency and insulation such as SiO 2 or Al 2 O 3 , on the positive electrode 15 so as to cover the entire region except the formation region of the positive electrode bonding pad 16, A protective layer is formed by a conventionally known method.
- a light emitting element chip (compound semiconductor light emitting element 1) can be obtained by cutting into a 350 ⁇ m square.
- a semiconductor layer forming step of sequentially stacking each layer made of a compound semiconductor on the substrate 11 to manufacture the semiconductor wafer 10, and a p-type semiconductor A conductive transparent electrode laminating step for laminating an amorphous transparent conductive film, for example, an IZO film, on the layer 14, an etching step for etching the transparent conductive film, for example, an IZO film, into a predetermined shape, and 300-800 for the transparent conductive film.
- the method includes each step including a heat treatment step for controlling the characteristics to be at least sec, a positive electrode (conductive translucent electrode) 15 having a particularly excellent light transmittance in the visible to ultraviolet region and having a low resistance can be obtained.
- a heat treatment step for controlling the characteristics to be at least sec a positive electrode (conductive translucent electrode) 15 having a particularly excellent light transmittance in the visible to ultraviolet region and having a low resistance can be obtained.
- the compound semiconductor light emitting device 1 having particularly excellent light emission output characteristics and a low driving voltage can be obtained.
- the compound semiconductor light emitting device according to the present invention can be configured with a transparent cover by means well known to those skilled in the art.
- a white lamp can also be comprised by combining the compound semiconductor light-emitting device which concerns on this invention, and the cover which has fluorescent substance.
- the gallium nitride compound semiconductor light emitting device of the present invention can be configured as an LED lamp without any limitation using a conventionally known method.
- the lamp can be used for any purpose such as a bullet type for general use, a side view type for portable backlight use, and a top view type used for a display.
- FIG. 4 is a schematic configuration diagram for explaining an example of the lamp of the present invention.
- a lamp 30 shown in FIG. 4 is obtained by mounting the compound semiconductor light emitting element 1 of the present embodiment configured as a face-up type as described above as a bullet-type lamp.
- the light emitting element 1 shown in FIG. 1 is bonded to one of the two frames 31 and 32 with a resin or the like, and the positive electrode bonding pad 16 and the negative electrode 17 are made of a wire 33 made of a material such as gold, 34 are joined to the frames 31, 32, respectively.
- a mold 35 made of a transparent resin is formed around the light emitting element 1.
- the semiconductor compound light-emitting element 1 according to the present invention is provided, the light emission characteristics are excellent.
- the lamp manufactured using the compound semiconductor light emitting element according to the present invention as described above has a high light emission output and a low driving voltage
- a mobile phone, a display, or a panel incorporating the lamp manufactured by such a technique is used.
- Such electronic devices as well as mechanical devices such as automobiles, computers, and game machines incorporating the electronic devices can be driven with low power, and can realize high device characteristics and device characteristics.
- the power saving effect is maximized.
- Example 1 (Relationship between heat treatment temperature of IZO film and sheet resistance)
- the relationship between the heat treatment (annealing) temperature of the IZO film and the sheet resistance of the IZO film after the heat treatment was examined by the following procedure. That is, an amorphous IZO film (thickness 250 nm) is formed on a sapphire substrate, and the sheet resistance when the obtained IZO film is heat-treated at 300 ° C. to 900 ° C. in an N 2 atmosphere is measured. The results are shown in the following Table 1 and the graph of FIG. The sheet resistance of the IZO film was measured using a four-probe method measuring device (manufactured by Mitsubishi Chemical Corporation: Loresta MP MCP-T360).
- Example 2 (Relationship between heat treatment temperature of IZO film and carrier concentration and mobility)
- the carrier concentration and mobility of the IZO film produced in Experimental Example 1 were measured by the van der Pauw method.
- the carrier concentration is shown in the graph of Table 1 and FIG. Is shown in the graph of Table 1 and FIG.
- the carrier mobility of the IZO film when the IZO film is annealed in an N 2 atmosphere is 30.9 cm 2 / V ⁇ sec at a processing temperature of 400 ° C.
- the treatment temperature was 600 ° C.
- it was 38.7 cm 2 / V ⁇ sec
- the treatment temperature was 700 ° C.
- it was 49.5 cm 2 / V ⁇ sec.
- the carrier mobility of the IZO film 35 cm in treatment temperature 800 ° C. in annealing 2 / V ⁇ sec, and the treatment temperature became at 900 °C 30.9cm 2 / V ⁇ sec .
- the annealing temperature is about 700 ° C., for example, about 650 to 750 ° C.
- the carrier mobility becomes the highest, and as the processing temperature becomes higher than 800 ° C., the carrier mobility increases. It can be seen that the mobility of decreases rapidly.
- FIGS. 10 to 18 are graphs showing X-ray diffraction data of the IZO film, in which the horizontal axis indicates the diffraction angle (2 ⁇ (°)) and the vertical axis indicates the diffraction intensity (s).
- a broad X-ray peak representing an amorphous state was observed in the IZO film before the heat treatment and the IZO film subjected to the heat treatment at a temperature of 300 ° C. or 400 ° C. From this observation result, it can be seen that the IZO film before the heat treatment and the IZO film subjected to the heat treatment at a temperature of 400 ° C. or less are in an amorphous state.
- FIGS. 10 to 12 are graphs showing X-ray diffraction data of the IZO film, in which the horizontal axis indicates the diffraction angle (2 ⁇ (°)) and the vertical axis indicates the diffraction intensity (s).
- Example 4 (Relationship between heat treatment temperature and light transmittance of IZO film)
- the relationship between the heat treatment temperature of the IZO film and the light transmittance of the IZO film was examined by the following procedure. That is, an amorphous IZO film (thickness 250 nm) is formed on a sapphire substrate, and the obtained IZO film without heat treatment and the IZO film heat-treated at temperatures of 500 ° C., 700 ° C., and 900 ° C. are optically transmitted. The rate was measured and shown in the graph of FIG.
- the light transmittance of the IZO film was measured using an ultraviolet-visible spectrophotometer UV-2450 manufactured by Shimadzu Corporation. The light transmittance value was obtained by measuring the light transmittance of only the sapphire substrate. It was calculated by subtracting the light transmission blank value.
- FIG. 19 is a graph showing the light transmittance of the IZO film.
- the horizontal axis indicates the wavelength (nm) and the vertical axis indicates the light transmittance (%).
- the light transmittance is higher than that of the IZO film without heat treatment or the IZO film heat-treated at other temperatures.
- the light transmittance is high in the ultraviolet light emitting region near 400 nm, and the light transmittance is also high in the blue light emitting region near 460 nm. It is done.
- the heat treatment temperature of the IZO film is preferably in the range of 500 to 800 ° C., more preferably in the range of 650 to 700 ° C.
- FIG. 3 is a schematic cross-sectional view of a semiconductor wafer made of a gallium nitride compound semiconductor layer, which is produced for use in the gallium nitride compound semiconductor light emitting device of this example.
- 1 and 2 are a schematic cross-sectional view and a schematic plan view of a gallium nitride-based compound semiconductor light-emitting device manufactured in this example.
- a laminated structure of the semiconductor wafer 20 made of a gallium nitride compound is sequentially undoped on a substrate 21 made of a c-plane ((0001) crystal face) of sapphire via a buffer layer (not shown) made of AlN.
- a gallium nitride compound semiconductor light emitting element (see FIG. 1) was fabricated.
- an IZO film was formed on the p-type GaN contact layer 27 by a sputtering method.
- the IZO film was formed with a film thickness of about 250 nm by DC magnetron sputtering.
- an IZO film was formed by using an IZO target having a ZnO concentration of 10 mass%, introducing Ar gas of 70 sccm, and setting the pressure to about 0.3 Pa.
- the sheet resistance of the IZO film formed by the above method was 17 ⁇ / sq. Moreover, it was confirmed that the IZO film immediately after the film formation was amorphous by X-ray diffraction (XRD).
- the IZO film was provided only in the positive electrode formation region on the p-type GaN contact layer 27 by a well-known photolithography method and wet etching method. At this time, the amorphous IZO film was etched at an etching rate of about 40 nm / min using ITO-07N as an etching solution. In this manner, the positive electrode of the present invention (see reference numeral 15 in FIGS. 1 and 2) was formed on the p-type GaN contact layer 27.
- heat treatment was performed at a temperature of 700 ° C. for 30 seconds using an RTA annealing furnace.
- the heat treatment of the IZO film is performed several times purging with N 2 gas before heated and subjected to RTA annealing furnace after the N 2 gas atmosphere.
- the IZO film after the heat treatment showed higher light transmittance in the wavelength region of 350 to 600 nm than that immediately after the film formation, and the sheet resistance was 10 ⁇ / sq.
- XRD X-ray diffraction
- the Ti layer is changed to a Pt layer (the layer thickness is the same as described above), and the thickness of the Au layer is changed to 1100 nm, the same as the Cr / Ti / Au laminated structure, It formed as a positive electrode bonding pad and a negative electrode.
- the back surface of the substrate made of sapphire was polished using fine diamond abrasive grains, and finally finished to a mirror surface. Thereafter, the semiconductor wafer 20 was cut, separated into individual 350 ⁇ m square chips, placed in a lead frame shape, and then connected to the lead frame with gold (Au) wires.
- the forward voltage (drive voltage: Vf) at a current application value of 20 mA was measured for the above-described chip by energization with a probe needle. Moreover, the light emission output (Po) and the light emission wavelength were measured using a general integrating sphere. It was confirmed that the light emission distribution on the light emitting surface emitted light on the entire surface of the positive electrode.
- the chip had an emission wavelength in the wavelength region near 460 nm, the driving voltage Vf was 3.1 V, and the emission output Po was 18.5 mW.
- the heat treatment temperatures of the IZO films were 300 ° C. (Comparative Example 1), 400 ° C. (Example 2), 500 ° C. (Example 3), 600 ° C. (Example 4), 800 ° C. (Example 5) and 900, respectively.
- a gallium nitride-based compound semiconductor light-emitting device was produced in the same manner as in Example 1 (700 ° C.) except for the point performed at 0 ° C. (Example 6), and evaluated in the same manner as in Example 1.
- the graph of FIG. 20 shows the relationship between the heat treatment temperature of the IZO film, the drive voltage Vf of the light emitting element, and the light emission output Po.
- the horizontal axis represents the heat treatment temperature (° C.) of the IZO film, and the vertical axis represents Vf (V) and Po (mW) of the light emitting element, respectively.
- Example 7 A gallium nitride-based compound semiconductor light-emitting device was fabricated in the same manner as in Example 1 except that an uneven shape was formed on the surface of the IZO film that did not contact the p-type semiconductor layer, that is, the light extraction surface side. Evaluation was performed in the same manner.
- the step of forming the concavo-convex shape was performed before the heat treatment of the IZO film, and wet etching was performed using an ITO-07N etching solution in the same manner as the patterning of the IZO film.
- the concavo-convex shape was a cylindrical concave shape having a diameter of 2 ⁇ m and a depth of 150 nm, and the cylindrical concave portions were arranged in a staggered manner with a center pitch of 3 ⁇ m.
- the light-emitting element thus obtained had Vf of 3.1 V and Po of 19.3 mW.
- Example 8 and Example 9 A gallium nitride-based compound semiconductor light emitting device was produced in the same manner as in Example 7 except that the depth of the cylindrical recess was set to 200 nm and 250 nm, respectively, and evaluated in the same manner as in Example 1.
- the graph of FIG. 21 shows the relationship between the depth of the recess on the surface of the IZO film, the drive voltage Vf of the light emitting element, and the light emission output Po.
- the horizontal axis represents the depth (nm) of the recess on the IZO film surface
- the vertical axis represents Vf (V) of the light emitting element and Po (mW) of the gallium nitride compound semiconductor light emitting element.
- the depth of the concave portion on the surface of the IZO film is 0, it indicates that the concave-convex shape is not formed (Example 1).
- the depth of the recess formed on the surface of the IZO film that does not contact the p-type semiconductor layer is deeper, the Po of the light emitting element is higher, and the depth of the recess is 250 nm. It was confirmed that when the surface of the p-type semiconductor layer of the element was exposed, Vf of the light emitting element increased.
- Example 10 Gallium nitride-based compound semiconductor light-emitting element as in Example 1, except that an ITO film (formed by sputtering method, film thickness of about 250 nm) is used instead of the IZO film as the positive electrode material, and the heat treatment temperature is 600 ° C. Was made.
- the sheet resistance of the ITO film was 15 ⁇ / sq. Further, as shown below, the relationship between the heat treatment temperature and crystallization of the ITO film was examined. That is, an amorphous ITO film (thickness 250 nm) is formed on a GaN epitaxial wafer, and the formed amorphous ITO film is heated at a temperature of 400 ° C. or 600 ° C. in an N 2 atmosphere.
- X-ray diffraction data was measured after heat treatment for 1 minute, and the results are shown in the graphs of FIGS.
- the X-ray diffraction data as described above is an index of the crystallinity of the ITO film.
- 22 to 23 are graphs showing X-ray diffraction data of the ITO film, the horizontal axis indicates the diffraction angle (2 ⁇ (°)), and the vertical axis indicates the diffraction intensity (s).
- a peak of a hexagonal crystal structure and a peak of an In 2 O 3 bixbite structure were observed. From this observation result, it can be seen that by performing heat treatment at a temperature of 400 ° C. to 600 ° C., the crystal structure in the ITO film includes a crystal having a composition of In 2 O 3 having a hexagonal crystal structure.
- Example 11 Gallium nitride-based compound semiconductor light emitting device as in Example 1, except that an IGO film (formed by sputtering method, film thickness of about 250 nm) is used instead of the IZO film as the positive electrode material, and the heat treatment temperature is 600 ° C. Was made.
- the sheet resistance of the IGO film was 40 ⁇ / sq.
- the relationship between the heat treatment temperature of the IGO film and crystallization was examined. That is, an amorphous IGO film (thickness 250 nm) was formed on a GaN epitaxial wafer, and X-ray diffraction data of the obtained IGO film without heat treatment was measured using an X-ray diffraction (XRD) method.
- XRD X-ray diffraction
- the compound semiconductor light-emitting device includes a positive electrode made of a conductive translucent electrode having a high light transmittance and is excellent in a light-emitting device.
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Led Devices (AREA)
- Electrodes Of Semiconductors (AREA)
Abstract
Description
本願は、2008年1月24日に、日本に出願された特願2008-014232号、2008年3月17日に、日本に出願された特願2008-068076号、2008年10月23日に、日本に出願された特願2008-273092号に基づき優先権を主張し、その内容をここに援用する。
従来、窒化ガリウム系化合物半導体発光素子の特徴として、横方向への電流拡散が小さい特性があり、電極直下の半導体層にしか電流が注入されないため、発光層で発光した光が電極によって遮られ、外部に取り出され難いという問題があった。そこで、このような窒化ガリウム系化合物半導体発光素子においては、通常、正極として透光性電極が用いられ、正極を通して光が取り出される構成とされている。
また、本発明は、上記化合物半導体発光素子が備えられ発光特性に優れるランプ、及びこのランプが組み込まれてなる電子機器、並びにこの電子機器が組み込まれてなる機械装置を提供することを目的とする。
即ち、本発明は以下に関する。
前記正極をなす導電型透光性電極が、六方晶構造を有するIn2O3なる組成の結晶を含む透明導電膜であることを特徴とする化合物半導体発光素子。
[2] 前記透明導電膜内におけるキャリアの移動度が30cm2/V・sec以上であることを特徴とする前項1に記載の化合物半導体発光素子。
[3] 前記透明導電膜内におけるキャリアのキャリア濃度が1×1020~5×1021cm-3の範囲であることを特徴とする前項1または前項2に記載の化合物半導体発光素子。
[4] 前記透明導電膜のシート抵抗が50Ω/sq以下であることを特徴とする前項1乃至3の何れか1項に記載の化合物半導体発光素子。
[5] 前記透明導電膜の厚さが35nm~10000nm(10μm)の範囲であることを特徴とする前項1乃至4の何れか1項に記載の化合物半導体発光素子。
[6] 前記透明導電膜の表面に凹凸加工がなされていることを特徴とする前項1乃至5の何れか1項に記載の化合物半導体発光素子。
[7] 前記透明導電膜の表面に複数個の独立した凹部が形成されていることを特徴とする前項6に記載の化合物半導体発光素子。
[8] 前記透明導電膜の凹部の合計面積が、前記透明導電膜全体の面積に対する割合で1/4~3/4の範囲であることを特徴とする前項7に記載の化合物半導体発光素子。
[9] 前記透明導電膜の凹部における前記透明導電膜の厚さが、凸部における前記透明導電膜の厚さの1/2以下であることを特徴とする前項6乃至8の何れか1項に記載の化合物半導体発光素子。
[10] 前記透明導電膜が、IZO膜、ITO膜、IGO膜のいずれかであることを特徴とする前項1乃至9の何れか1項に記載の化合物半導体発光素子。
[11] 前記透明導電膜が、IZO膜であり、 前記IZO膜中のZnO含有量が1~20質量%の範囲であることを特徴とする前項1乃至10の何れか1項に記載の化合物半導体発光素子。
[12] 前記化合物半導体が、窒化ガリウム系化合物半導体であることを特徴とする前項1乃至11の何れか1項に記載の化合物半導体発光素子。
[13] 前記導電型透光性電極からなる正極が前記p型半導体層上に設けられ、前記導電型電極からなる負極が前記n型半導体層上に設けられていることを特徴とする前項1乃至12の何れか1項に記載の化合物半導体発光素子。
(a)基板上に、化合物半導体からなるn型半導体層、発光層及びp型半導体層をこの順で積層して半導体ウェーハを作製する半導体層形成工程、
(b)前記p型半導体層にアモルファス状の透明導電膜を積層する導電型透光性電極積層工程、
(c)前記透明導電膜を所定形状にエッチングするエッチング工程、及び、
(d)エッチングされた前記透明導電膜に対して、300~800℃の温度範囲で保持時間を制御しながら熱処理を行なうことにより、前記透明導電膜を、六方晶構造を有するIn2O3なる組成の結晶を含み、且つ、膜内におけるキャリアの移動度が30cm2/V・sec以上の特性に制御する熱処理工程。
[15] 前記透明導電膜が、IZO膜、ITO膜、IGO膜のいずれかであることを特徴とする前項14に記載の化合物半導体発光素子の製造方法。
[16] 前記(d)に示す熱処理工程は、前記透明導電膜に対して、300~800℃の温度範囲で保持時間を制御しながら熱処理を行なうことにより、前記透明導電膜を、六方晶構造を有するIn2O3なる組成の結晶を含み、且つ、膜内におけるキャリアの移動度が30~100cm2/V・secの範囲の特性に制御することを特徴とする前項14または前項15に記載の化合物半導体発光素子の製造方法。
[17] 前記(b)に示す導電型透光性電極積層工程は、スパッタリング法によって前記透明導電膜を積層することを特徴とする前項14乃至16の何れか1項に記載の化合物半導体発光素子の製造方法。
[18] 前記化合物半導体が窒化ガリウム系化合物半導体であることを特徴とする前項14乃至17の何れか1項に記載の化合物半導体発光素子の製造方法。
[19] 前記透明導電膜を、前記p型半導体層上に積層して形成することを特徴とする前項14乃至18の何れか1項に記載の化合物半導体発光素子の製造方法。
[21] 少なくとも六方晶構造を有するIn2O3なる組成の結晶を含む透明導電膜からなり、且つ、膜内におけるキャリアの移動度が30cm2/V・sec以上であることを特徴とする化合物半導体発光素子用導電型透光性電極。
[22] 膜内におけるキャリアの移動度が30~100cm2/V・secの範囲であることを特徴とする前項21に記載の化合物半導体発光素子用導電型透光性電極。
[23] 膜内のキャリア濃度が1×1020~5×1021cm-3の範囲であることを特徴とする前項21又は前項22に記載の化合物半導体発光素子用導電型透光性電極。
[24] 前項1乃至13又は前項20の何れか1項に記載の化合物半導体発光素子が備えられてなるランプ。
[25] 前項24に記載のランプが組み込まれてなる電子機器。
[26] 前項25に記載の電子機器が組み込まれてなる機械装置。
[27] 基板上に、化合物半導体からなるn型半導体層、発光層及びp型半導体層がこの順で積層され、さらに、導電型透光性電極からなる正極及び導電型電極からなる負極を備えてなる化合物半導体発光素子であって、前記正極をなす導電型透光性電極が結晶化されたIZO膜からなり、該IZO膜が六方晶構造を有するIn2O3なる組成の結晶を含む膜であることを特徴とする化合物半導体発光素子。
[28] 前記IZO膜内におけるキャリアの移動度が30cm2/V・sec以上であることを特徴とする前項27に記載の化合物半導体発光素子。
[29] 前記IZO膜内におけるキャリアの移動度が35cm2/V・sec以上であることを特徴とする前項28に記載の化合物半導体発光素子。
[30] 前記IZO膜内におけるキャリアの移動度が38cm2/V・sec以上であることを特徴とする前項28に記載の化合物半導体発光素子。
[31] 前記IZO膜内におけるキャリアの移動度が30~100cm2/V・secの範囲であることを特徴とする前項28に記載の化合物半導体発光素子。
[33] 前記IZO膜内におけるキャリアのキャリア濃度が1×1020~5×1021cm-3の範囲であることを特徴とする前項27乃至32の何れか1項に記載の化合物半導体発光素子。
[34] 前記IZO膜のシート抵抗が50Ω/sq以下であることを特徴とする前項27乃至33の何れか1項に記載の化合物半導体発光素子。
[35] 前記IZO膜中のZnO含有量が1~20質量%の範囲であることを特徴とする前項27乃至34の何れか1項に記載の化合物半導体発光素子。
[36] 前記IZO膜の厚さが35nm~10000nm(10μm)の範囲であることを特徴とする前項27乃至35の何れか1項に記載の化合物半導体発光素子。
[37] 前記IZO膜の表面に凹凸加工がなされていることを特徴とする前項27乃至36の何れか1項に記載の化合物半導体発光素子。
[38] 前記IZO膜の表面に複数個の独立した凹部が形成されていることを特徴とする前項37に記載の化合物半導体発光素子。
[39] 前記IZO膜の凹部の合計面積が、IZO膜全体の面積に対する割合で1/4~3/4の範囲であることを特徴とする前項38に記載の化合物半導体発光素子。
[40] 前記IZO膜の凹部におけるIZO膜の厚さが、凸部におけるIZO膜の厚さの1/2以下であることを特徴とする前項37乃至39の何れか1項に記載の化合物半導体発光素子。
[41] 前記化合物半導体が、窒化ガリウム系化合物半導体であることを特徴とする前項27乃至40の何れか1項に記載の化合物半導体発光素子。
[42] 前記導電型透光性電極からなる正極が前記p型半導体層上に設けられ、前記導電型電極からなる負極が前記n型半導体層上に設けられていることを特徴とする前項27乃至41の何れか1項に記載の化合物半導体発光素子。
(a)基板上に、化合物半導体からなるn型半導体層、発光層及びp型半導体層をこの順で積層して半導体ウェーハを作製する半導体層形成工程、
(b)前記p型半導体層にアモルファス状のIZO膜を積層する導電型透光性電極積層工程、
(c)前記IZO膜を所定形状にエッチングするエッチング工程、及び、
(d)エッチングされた前記IZO膜に対して、500~800℃の温度範囲で保持時間を制御しながら熱処理を行なうことにより、前記IZO膜を、六方晶構造を有するIn2O3なる組成の結晶を含み、且つ、膜内におけるキャリアの移動度が30cm2/V・sec以上の特性に制御する熱処理工程。
[44] 前記(d)に示す熱処理工程は、前記IZO膜に対して、500~800℃の温度範囲で保持時間を制御しながら熱処理を行なうことにより、前記IZO膜を、六方晶構造を有するIn2O3なる組成の結晶を含み、且つ、膜内におけるキャリアの移動度が30~100cm2/V・secの範囲の特性に制御することを特徴とする前項43に記載の化合物半導体発光素子の製造方法。
[45] 前記(b)に示す導電型透光性電極積層工程は、スパッタリング法によって前記IZO膜を積層することを特徴とする前項43又は前項44に記載の化合物半導体発光素子の製造方法。
[46] 前記化合物半導体が窒化ガリウム系化合物半導体であることを特徴とする前項43乃至45の何れか1項に記載の化合物半導体発光素子の製造方法。
[47] 前記IZO膜を、前記p型半導体層上に積層して形成することを特徴とする前項43乃至46の何れか1項に記載の化合物半導体発光素子の製造方法。
[49] 少なくとも六方晶構造を有するIn2O3なる組成の結晶を含むIZO膜からなり、且つ、膜内におけるキャリアの移動度が30cm2/V・sec以上であることを特徴とする化合物半導体発光素子用導電型透光性電極。
[50] 膜内におけるキャリアの移動度が30~100cm2/V・secの範囲であることを特徴とする前項48に記載の化合物半導体発光素子用導電型透光性電極。
[51] 膜内のキャリア濃度が1×1020~5×1021cm-3の範囲であることを特徴とする前項49又は前項50に記載の化合物半導体発光素子用導電型透光性電極。
[52] 前項27乃至42又は前項48の何れか1項に記載の化合物半導体発光素子が備えられてなるランプ。
[53] 前項52に記載のランプが組み込まれてなる電子機器。
[54] 前項53に記載の電子機器が組み込まれてなる機械装置。
またさらに、導電型透光性電極をなす透明導電膜内におけるキャリアの移動度が30cm2/V・sec以上に制御された構成とすることにより、低抵抗の正極とすることができ、駆動電圧の低い化合物半導体発光素子が実現できる。
本発明の化合物半導体発光素子によれば、基板上に化合物半導体からなる各層が積層され、さらに導電型透光性電極からなる正極及び導電型電極からなる負極を備え、正極をなす導電型透光性電極は結晶化されたIZO膜からなり、該IZO膜が六方晶構造を有するIn2O3なる組成の結晶を含む構成なので、可視から紫外領域において特に高い光透過率を有する導電型透光性電極とすることができ、発光素子の光取り出し特性が高められる。これにより、格別に優れた発光出力特性を有する化合物半導体発光素子が実現できる。
またさらに、導電型透光性電極をなすIZO膜内におけるキャリアの移動度が30cm2/V・sec以上に制御された構成とすることにより、低抵抗の正極とすることができ、駆動電圧の低い化合物半導体発光素子が実現できる。
また、本発明の化合物半導体発光素子の製造方法によれば、基板上に化合物半導体からなる各層を積層して半導体ウェーハを作製する半導体層形成工程と、p型半導体層にアモルファス状のIZO膜を積層する導電型透光性電極積層工程と、IZO膜を所定形状にエッチングするエッチング工程と、IZO膜に対して500~800℃の温度範囲で保持時間を制御しながら熱処理を行なうことにより、IZO膜を、六方晶構造を有するIn2O3なる組成の結晶を含み、且つ、膜内におけるキャリアの移動度が30cm2/V・sec以上の特性に制御する熱処理工程との各工程を含む方法なので、可視から紫外領域において特に優れた光透過率を有する導電型透光性電極を備え、格別に優れた発光出力特性を有し、なおかつ低駆動電圧の化合物半導体発光素子が得られる。
また、本発明の化合物半導体発光素子用透光性電極によれば、少なくとも六方晶構造を有するIn2O3なる組成の結晶を含むIZO膜からなり、且つ、膜内におけるキャリアの移動度が30cm2/V・sec以上である構成なので、低抵抗かつ優れた透光性を有する電極が得られる。
また、本発明の電子機器によれば、上記本発明のランプが組み込まれてなるものなので、機器特性に優れたものとなり、また、本発明の機械装置によれば、上記本発明の電子機器が組み込まれてなるものなので、装置特性に優れたものとなる。
また、本発明は、窒化ガリウム系化合物半導体発光素子に限定されるものではなく、上述の各種化合物半導体を用いた発光素子に適用される。
本実施形態の化合物半導体発光素子(以下、発光素子と略称することがある)1は、図1に示す例のように、基板11上に、化合物半導体(以下、半導体と略称することがある)からなるn型半導体層12、発光層13及びp型半導体層14がこの順で積層され、さらに導電型透光性電極からなる正極15及び導電型電極17からなる負極を備えてなるものである。正極15をなす導電型透光性電極は、六方晶構造を有するIn2O3なる組成の結晶を含む透明導電膜から構成されている。例えば、正極15をなす導電型透光性電極は、結晶化されたIZO膜からなり、該IZO膜が六方晶構造を有するIn2O3なる組成の結晶を含むものとすることができる。
また、図示例の発光素子1は、導電型透光性電極からなる正極15の上に導電型電極か材料からなる正極ボンディングパッド16が設けられている。
以下、本実施形態の発光素子1の積層構造について説明する。
基板11の材料には、サファイア単結晶(Al2O3;A面、C面、M面、R面)、スピネル単結晶(MgAl2O4)、ZnO単結晶、LiAlO2単結晶、LiGaO2単結晶、MgO単結晶などの酸化物単結晶、Si単結晶、SiC単結晶、GaAs単結晶、AlN単結晶、GaN単結晶及びZrB2のホウ化物単結晶等、公知の基板材料を何ら制限なく用いることができる。
なお、基板の面方位は特に限定されない。また、ジャスト基板でも良いしオフ角を付与した基板であっても良い。
n型半導体層12、発光層13及びp型半導体層14としては、各種構造のものが周知であり、これら周知のものを何ら制限なく用いることができる。特に、p型半導体層14には、キャリア濃度が一般的な濃度のものを用いれば良く、比較的キャリア濃度の低い、例えば1×1017cm-3程度のp型半導体層に対しても、本発明で用いられ、詳細を後述する透明導電膜からなる正極15を適用することができる。
上述したような半導体層の最上層に設けられるp型半導体層14の上には、導電型透光性電極からなる正極15が積層される。本実施形態の正極15をなす導電型透光性電極は、六方晶構造を有するIn2O3なる組成の結晶を含む透明導電膜から構成されている。
透明導電膜は、IZO(インジウム・亜鉛系酸化物)膜、ITO(インジウム・スズ系酸化物)膜、IGO(インジウム・ガリウム系酸化物)膜のいずれかであることが好ましい。
例えば、本実施形態の正極15をなす導電型透光性電極は、結晶化されたIZO(インジウム・亜鉛系酸化物)膜からなるとともに、該IZO膜が六方晶構造を有するIn2O3なる組成の結晶を含むものとすることができる。
正極(導電型透光性電極)15を、膜内におけるキャリアの移動度が上記範囲となるように制御した構成とすることにより、特に、可視から紫外領域において特に優れた光透過率を有する正極が得られ、ひいては発光素子1の発光出力特性が向上する。
なお、本発明において説明する移動度とは、電界のもとで荷電粒子、即ちキャリアが移動する際、その移動速度を電界の強さで割った量である。
さらに、本発明においては、正極15をなす透明導電膜のシート抵抗は、電流を効率良く拡散するためには、50Ω/sq以下であることが好ましく、20Ω/sq以下であることがより好ましい。
In2O3なる組成を有する結晶は、ビックスバイト構造の立方晶構造と、六方晶構造の2種類の構造が知られている。本発明において正極15として用いられる透明導電膜においては、六方晶構造のIn2O3だけでなく立方晶構造のIn2O3を含む構成とすることが可能である。本発明において正極15として用いられるIZO膜においても、六方晶構造のIn2O3や立方晶構造のIn2O3を含む構成とすることが可能となる。
一方、本発明者等が鋭意実験したところによれば、上述のような透明導電膜(例えばIZO膜)は、加熱条件が適性でない場合は、六方晶構造からビックスバイト(立方晶)構造への転移が起こり、結果的にシート抵抗の上昇が発生し、化合物半導体発光素子用の導電型透光性電極としての特性が低下してしまうことが明らかとなった。また、透明導電膜がIZO膜からなるものである場合、IZO膜は、熱処理条件によっては、Znのマイグレーション(移動)によるIZO組成の不均一化が起こることも明らかとなった。
本発明に係る化合物半導体発光素子に備えられる正極は、上記構成を有し、また、詳細を後述する熱処理工程の条件を適正に制御することにより、優れた光透過率を有する導電型透光性電極となる。
負極17は、正極15を構成する透明導電膜、例えばIZO膜を熱処理した後(後述の熱処理工程を参照)、図1及び図2に示すように、p型半導体層14、発光層13及びn型半導体層12の一部をエッチングによって除去してn型半導体層12の一部を露出させ、この露出したn型半導体層12上に、例えば、Ti/Auからなる従来公知の負極17を設ける。負極17としては、各種組成および構造の負極が周知であり、これら周知の負極を何ら制限無く用いることができる。
正極(導電型透光性電極)15をなす透明導電膜上、例えばIZO膜上の少なくとも一部には、発光素子外部の回路基板やリードフレーム等と電気的に接続するための正極ボンディングパッド16が設けられている。正極ボンディングパッド16としては、Au、Al、Ni及びCu等の材料を用いた各種構造が周知であり、これら周知の材料、構造のものを何ら制限無く用いることができる。
また、正極ボンディングパッド16の厚さとしては、100~1000nmの範囲であることが好ましい。また、ボンディングパッドの特性上、厚さが大きい方が、ボンダビリティーが高くなるため、正極ボンディングパッド16の厚さは300nm以上とすることがより好ましい。さらに、製造コストの観点から500nm以下とすることが好ましい。
本実施形態では、透明導電膜、例えばIZO膜からなる正極15の酸化を防ぐため、正極15上に図示略の保護層が設けられた構成とすることがより好ましい。このような保護層としては、正極ボンディングパッド16が形成される領域を除く正極15上の全領域を覆うため、透光性に優れた材料を用いることが好ましく、また、p型半導体層14とn型半導体層12とのリークを防ぐために絶縁性材料からなることが好ましく、例えば、SiO2やAl2O3等を用いれば良い。また、保護層の膜厚としては、透明導電膜、例えばIZO膜からなる正極15の酸化を防ぐことができ、かつ透光性が維持できる膜厚であれば良く、具体的には、例えば、20nm~500nmの範囲であることが好ましい。
また、本実施形態の化合物半導体発光素子によれば、基板11上に化合物半導体からなる各層が積層され、さらに導電型透光性電極からなる正極15及び導電型電極からなる負極17を備え、正極15をなす導電型透光性電極は結晶化されたIZO膜からなり、該IZO膜が六方晶構造を有するIn2O3なる組成の結晶を含む構成なので、可視から紫外領域において特に高い光透過率を有する導電型透光性電極とすることができ、発光素子1の光取り出し特性が高められる。これにより、格別に優れた発光出力特性を有する化合物半導体発光素子1が実現できる。またさらに、正極(導電型透光性電極)15をなす透明導電膜内、例えばIZO膜内におけるキャリアの移動度が30cm2/V・sec以上に制御された構成とすることにより、正極15を低抵抗化し、駆動電圧の低い化合物半導体発光素子1が実現できる。
また、本実施形態の化合物半導体発光素子1に用いられる正極(化合物半導体発光素子用透光性電極)15によれば、六方晶構造を有するIn2O3なる組成の結晶を含むIZO膜からなり、且つ、膜内におけるキャリアの移動度が30cm2/V・sec以上である構成なので、優れた透光性及び低抵抗性が得られる。
本実施形態の化合物半導体発光素子の製造方法は、少なくとも下記(a)~(d)に示す各工程を含む方法により、図1及び図2に例示するような発光素子1を製造する方法である。
(a)基板11上に、化合物半導体からなるn型半導体層12、発光層13及びp型半導体層14をこの順で積層して半導体ウェーハ10を作製する半導体層形成工程、
(b)p型半導体層14にアモルファス状の透明導電膜、例えばIZO膜を積層する導電型透光性電極積層工程、
(c)透明導電膜、例えばIZO膜を所定形状にエッチングするエッチング工程、及び、
(d)エッチングされた透明導電膜、例えばIZO膜に対して、500~800℃の温度範囲で保持時間を制御しながら熱処理を行なうことにより、透明導電膜を、例えばIZO膜を、六方晶構造を有するIn2O3なる組成の結晶を含み且つ移動度が30cm2/V・sec以上の特性に制御し、正極15とする熱処理工程。
本実施形態の製造方法では、まず、上記(a)に示した半導体層形成工程において、基板11上に、化合物半導体からなるn型半導体層12、発光層13及びp型半導体層14をこの順で積層して半導体ウェーハ10を作製する。
具体的には、基板11上に、例えばAlN等からなる図示略のバッファ層を形成した後、このバッファ層上に、窒化ガリウム系化合物半導体をエピタキシャル成長させることによってn型半導体層12、発光層13及びp型半導体層14を順次積層し、半導体層を形成する。
また、ドーパントとしては、n型半導体層12には、Si原料としてモノシラン(SiH4)またはジシラン(Si2H6)を、Ge原料としてゲルマン(GeH4)または有機ゲルマニウム化合物を用い、p型半導体層には、Mg原料としては例えばビスシクロペンタジエニルマグネシウム(Cp2Mg)またはビスエチルシクロペンタジエニルマグネシウム((EtCp)2Mg)等を用いることができる。
次いで、上記(b)に示した導電型透光性電極形成工程において、上記半導体層形成工程で形成された半導体層のp型半導体層14上に、透明導電膜、例えばIZO膜からなる正極(導電型透光性電極)15を形成する。
スパッタ法を用いて透明導電膜としてIZO膜を形成する場合には、In2O3ターゲットとZnOターゲットを、RFマグネトロンスパッタ法によって公転成膜することで形成することが可能であるが、成膜速度をより高くするためには、IZOターゲットに対するパワーの印加をDCマグネトロンスパッタ法によって行うことが好ましい。また、p型半導体層14へのプラズマによるダメージを軽減するため、スパッタの放電出力は1000W以下であることが好ましい。
次いで、上記(c)に示したエッチング工程において、上記導電型透光性電極形成工程で成膜されたアモルファス状態の透明導電膜、例えばIZO膜を所定形状にエッチングする。
具体的には、周知のフォトリソグラフィー法及びエッチング法を用いて透明導電膜、例えばIZO膜をパターニングすることにより、p型半導体層14上の正極15の形成領域を除く領域の透明導電膜を除去し、図2に示すように、正極15の形成領域にのみ透明導電膜が形成された状態となる。
また、アモルファス状態の透明導電膜、例えばIZO膜のエッチングは、ドライエッチング装置を用いて行なっても良い。この際、エッチングガスとしては、Cl2、SiCl4、BCl3等を用いることができる。
図5A、図5B及び図6に示すように、エッチング法を用いて透明導電膜表面、例えばIZO膜表面に凹凸加工を施すことによって正極の光透過率を向上させ、発光素子の発光出力を向上させることができる。透明導電膜表面、例えばIZO膜表面への凹凸加工によって発光出力が向上する理由としては、1.正極の薄膜化による光透過率の向上、2.凹凸加工による光取り出し面積(透明導電膜表面積)の増加、3.正極表面での全反射の低減等が考えられる。また、透明導電膜表面、例えばIZO膜表面への凹凸加工の形状としては、上記1~3の理由により、どのような形状であっても出力向上効果があるが、特に、凹凸側面の面積を大きくすることができることから、図5A、図5B及び図6に示すようなドット形状とすることがより好ましい。
次いで、上記(d)に示した熱処理工程では、上記エッチング工程においてパターニングされた透明導電膜に対して熱処理を行なう。
具体的には、パターニングされた透明導電膜に対し、300~800℃の温度範囲で保持時間を制御しながら熱処理を行なうことにより、透明導電膜を、六方晶構造を有するIn2O3なる組成の結晶を含み、且つ、膜内のキャリア移動度が30cm2/V・sec以上の特性に制御し、正極15とする。
また、上記(d)に示した熱処理工程では、上記エッチング工程においてパターニングされたIZO膜表面に対して熱処理を行なってもよい。
具体的には、パターニングされたIZO膜に対し、500~800℃の温度範囲で保持時間を制御しながら熱処理を行なうことにより、IZO膜を、六方晶構造を有するIn2O3なる組成の結晶を含み、且つ、膜内のキャリア移動度が30cm2/V・sec以上の特性に制御し、正極15とする。
アモルファス状態のIZO膜は、例えば、500~800℃の温度範囲の熱処理を行なうことにより、結晶化したIZO膜表面となる。このように、IZO膜を結晶化することで、発光素子の発光波長、例えば、可視光域から紫外光域までの光の透過率を向上させることが可能となり、特に、380nm~500nmの波長領域において大幅に光透過率が向上する。
なお、上述したように、結晶化した透明導電膜、例えばIZO膜はエッチング処理が困難となるので、熱処理工程は、上記エッチング工程の後に行うことが好ましい。
また、透明導電膜の熱処理を800℃超の温度で行なった場合には、透明導電膜は結晶化されるものの、光透過率が充分に高い膜とならない虞がある。また、800℃を超える温度で熱処理を行なった場合、透明導電膜の下にある半導体層を劣化させる虞がある。
IZO膜の熱処理温度は、500~800℃の範囲であることが好ましい。IZO膜の熱処理を500℃未満の温度で行なった場合、IZO膜を十分に結晶化できない場合があり、IZO膜の光透過率が充分に高い膜とならない虞がある。また、IZO膜の熱処理を800℃超の温度で行なった場合には、IZO膜は結晶化されるものの、光透過率が充分に高い膜とならない虞がある。また、800℃を超える温度で熱処理を行なった場合、IZO膜の下にある半導体層を劣化させる虞がある。
次いで、上記半導体層形成工程において形成されたn型半導体層12、発光層13及びp型半導体層14からなる半導体層の一部を除去することにより、n型半導体層12を露出させ、負極17を形成する。
具体的には、図1及び図2に示すように、p型半導体層14、発光層13及びn型半導体層12の一部をエッチングによって除去することによってn型半導体層12の一部を露出させ、この露出したn型半導体層12上に、例えば、Ti/Auからなる負極17を従来公知の方法によって形成する。
次いで、正極(導電型透光性電極)15をなす透明導電膜、例えばIZO膜上に、正極ボンディングパッド16を形成する。
具体的には、図1及び図2に示すように、透明導電膜(正極15)、例えばIZO膜(正極15)上の少なくとも一部に、Au、Al、Ni及びCu等の材料を用いて、従来公知の方法によって正極ボンディングパッド16を形成する。
次いで、本実施形態では、正極15をなす透明導電膜、例えばIZO膜の酸化防止のため、正極15上に図示略の保護層を形成する。
具体的には、SiO2やAl2O3等の、透光性及び絶縁性を有する材料を用いて、正極15上において、正極ボンディングパッド16の形成領域を除く全領域を覆うようにして、従来公知の方法で保護層を形成する。
次いで、上記各手順により、半導体層上に正極15、正極ボンディングパッド16及び負極17が形成された半導体ウェーハ10を、基板11の裏面を研削及び研磨してミラー状の面とした後、例えば、350μm角の正方形に切断することにより、発光素子チップ(化合物半導体発光素子1)とすることができる。
以上説明したような、本発明に係る化合物半導体発光素子は、例えば、当業者周知の手段により、透明カバーを設けてランプを構成することができる。また、本発明に係る化合物半導体発光素子と蛍光体を有するカバーとを組み合わせることにより、白色のランプを構成することもできる。
また、上述のようなランプ30によれば、上記本発明に係る半導体化合物発光素子1が備えられてなるものなので、発光特性に優れたものとなる。
上述したような、本発明に係る化合物半導体発光素子を用いて作製したランプは、発光出力が高く、また駆動電圧が低いので、このような技術によって作製したランプを組み込んだ携帯電話、ディスプレイ、パネル類等の電子機器や、この電子機器を組み込んだ自動車、コンピュータ、ゲーム機等の機械装置は、低電力での駆動が可能となり、高い機器特性並びに装置特性を実現することが可能である。特に、携帯電話、ゲーム機、玩具、自動車部品等のバッテリ駆動させる機器類においては、省電力の効果を最大限に発揮する。
実験例1においては、IZO膜の熱処理(アニール処理)温度と、熱処理後のIZO膜のシート抵抗との関係を以下のような手順で調べた。
即ち、サファイア基板上にアモルファス状態のIZO膜(厚さ250nm)を形成し、得られたIZO膜を、300℃~900℃の各温度で、N2雰囲気中で熱処理した場合のシート抵抗を測定し、結果を下記表1及び図7のグラフに示した。なお、IZO膜のシート抵抗は、四探針法の測定装置(三菱化学社製:Loresta MP MCP-T360)を用いて測定した。
実験例2においては、上記実験例1で作製したIZO膜のキャリア濃度及び移動度を、van der Pauw法により測定し、キャリア濃度を上記表1及び図8のグラフに示すとともに、キャリアの移動度を上記表1及び図9のグラフに示した。
実験例3においては、IZO膜の熱処理温度と、IZO膜の結晶化との関係を以下のような手順で調べた。
即ち、GaNエピタキシャルウェーハ上にアモルファス状態のIZO膜(厚さ250nm)を形成し、得られた熱処理なしのIZO膜のX線回析データを、X線回折(XRD)法を用いて測定した。また、同様にして、GaNエピタキシャルウェーハ上に形成したアモルファス状態のIZO膜に対して、300℃~900℃の各温度で、N2雰囲気中で1分間の熱処理を行なった場合のX線回析データを測定し、結果を図10~18のグラフに示した。上述のようなX線回析データは、IZO膜の結晶性の指標となる。
図10~12に示すように、熱処理前のIZO膜及び300℃又は400℃の温度で熱処理を行なったIZO膜においては、アモルファス状態を表すブロードなX線のピークが観察された。この観察結果より、熱処理前のIZO膜及び400℃以下の温度で熱処理を行なったIZO膜がアモルファス状態であることがわかる。
また、図13~17に示すように、500~800℃の温度で熱処理を行なったIZO膜においては、結晶化ピークを示すX線のピークが観察された。この観察結果より、500~800℃の温度で熱処理を行なったIZO膜が結晶化されていることがわかる。また、図14~16に示すように、特に600℃~650℃~700℃の熱処理温度において、非常に高いX線のピーク強度が観察されることから、この範囲の温度で熱処理を行なうことにより、IZO膜が、六方晶構造を有するIn2O3なる組成の結晶を含む膜となることがわかる。
また、図18に示すように、900℃の温度で熱処理を行なったIZO膜においては、800℃以下の熱処理温度では見られなかったビックスバイト構造のピークが観察された。
この観察結果より、900℃の温度で熱処理を行なったIZO膜中の結晶構造が、六方晶構造からビックスバイト構造に転位していることがわかる。
実験例4においては、IZO膜の熱処理温度と、IZO膜の光透過率との関係を以下のような手順で調べた。
即ち、サファイア基板上にアモルファス状態のIZO膜(厚さ250nm)を形成し、得られた熱処理なしのIZO膜、及び、500℃、700℃、900℃の各温度で熱処理したIZO膜の光透過率を測定し、図19のグラフに示した。なお、IZO膜の光透過率測定には、島津製作所社製の紫外可視分光光度計UV-2450を用い、また、光透過率の値は、サファイア基板のみの光透過率を測定して得られた光透過ブランク値を差し引いて算出した。
図19に示すように、700℃の温度でIZO膜を熱処理した場合、熱処理なしのIZO膜やその他の温度で熱処理したIZO膜に比べて光透過率が高くなっていることがわかる。特に、700℃の温度でIZO膜を熱処理した場合には、400nm付近の紫外発光領域において光透過率が高く、また、460nm付近の青色発光領域においても光透過率が高くなっていることが認められる。
一方、900℃の温度でIZO膜を熱処理した場合、IZO膜の光透過率が充分に高められていないことがわかる。従って、IZO膜の熱処理温度は500~800℃の範囲であることが好ましく、650~700℃の範囲であることがより好ましいことが明らかである。
図3に、本実施例の窒化ガリウム系化合物半導体発光素子に用いるために作製した、窒化ガリウム系化合物半導体層からなる半導体ウェーハの断面模式図を示す。また、図1及び図2に、本実施例で作製した窒化ガリウム系化合物半導体発光素子の断面模式図、及び平面模式図を示す。以下、これら図1~3を適宜参照しながら説明する。
上述のようなチップについて、プローブ針による通電により、電流印加値20mAにおける順方向電圧(駆動電圧:Vf)を測定した。また、一般的な積分球を用いて発光出力(Po)及び発光波長を測定した。発光面の発光分布は、正極の全面で発光していることが確認できた。
チップは460nm付近の波長領域に発光波長を有しており、駆動電圧Vfは3.1V、発光出力Poは18.5mWであった。
IZO膜の熱処理温度を、それぞれ、300℃(比較例1)、400℃(実施例2)、500℃(実施例3)、600℃(実施例4)、800℃(実施例5)及び900℃(実施例6)として行なった点を除き、実施例1(700℃)と同様に窒化ガリウム系化合物半導体発光素子を作製し、実施例1と同様に評価した。
図20のグラフに、IZO膜の熱処理温度と発光素子の駆動電圧Vf及び発光出力Poとの関係を示す。横軸はIZO膜の熱処理温度(℃)、縦軸はそれぞれ発光素子のVf(V)及びPo(mW)を示している。
IZO膜のp型半導体層と接触しない側の表面、つまり光取り出し面側に凹凸形状を形成した点を除き、実施例1と同様に窒化ガリウム系化合物半導体発光素子を作製し、実施例1と同様に評価した。
このようにして得られた発光素子のVfは3.1V、Poは19.3mWであった。
円柱形の凹部の深さを、それぞれ200nm、250nmとした点を除き、実施例7と同様に窒化ガリウム系化合物半導体発光素子を作製し、実施例1と同様に評価した。
図21のグラフに、IZO膜表面の凹部の深さと発光素子の駆動電圧Vf及び発光出力Poとの関係を示す。図21において、横軸はIZO膜表面の凹部の深さ(nm)、縦軸にはそれぞれ、発光素子のVf(V)、及び窒化ガリウム系化合物半導体発光素子のPo(mW)を示している。なお、IZO膜表面の凹部の深さが0の場合は、凹凸形状を形成していない(実施例1)ことを示している。
正極の材料としてIZO膜の代わりに、ITO膜(スパッタリング法による形成、膜厚約250nm)を用い、熱処理温度を600℃としたこと以外は、実施例1と同様に窒化ガリウム系化合物半導体発光素子を作製した。なお、ITO膜のシート抵抗は15Ω/sqであった。
また、以下に示すようにして、ITO膜の熱処理温度と結晶化との関係を調べた。
即ち、GaNエピタキシャルウェーハ上にアモルファス状態のITO膜(厚さ250nm)を形成し、形成されたアモルファス状態のITO膜に対して、400℃の温度、または600℃の温度で、N2雰囲気中で1分間の熱処理を行なった場合のX線回析データを測定し、結果を図22~23のグラフに示した。上述のようなX線回析データは、ITO膜の結晶性の指標となる。
図22~23は、ITO膜のX線回折データ示すグラフであり、横軸は回折角(2θ(°))を示し、縦軸は回析強度(s)を示している。
図22~23に示すように、400℃の温度または600℃の温度で熱処理を行なったITO膜においては、六方晶構造のピークとIn2O3ビックスバイト構造のピークとが観察された。この観察結果より、400℃~600℃の温度で熱処理を行うことにより、ITO膜中の結晶構造は、六方晶構造を有するIn2O3なる組成の結晶を含むものになることがわかる。
正極の材料としてIZO膜の代わりに、IGO膜(スパッタリング法による形成、膜厚約250nm)を用い、熱処理温度を600℃としたこと以外は、実施例1と同様に窒化ガリウム系化合物半導体発光素子を作製した。なお、IGO膜のシート抵抗は40Ω/sqであった。
また、以下に示すようにして、IGO膜の熱処理温度と結晶化との関係を調べた。
即ち、GaNエピタキシャルウェーハ上にアモルファス状態のIGO膜(厚さ250nm)を形成し、得られた熱処理なしのIGO膜のX線回析データを、X線回折(XRD)法を用いて測定した。また、同様にして、GaNエピタキシャルウェーハ上に形成したアモルファス状態のIGO膜に対して、200℃、400℃、600℃の各温度で、N2雰囲気中で1分間の熱処理を行なった場合のX線回析データを測定し、結果を図24~図27のグラフに示した。上述のようなX線回析データは、IGO膜の結晶性の指標となる。
図24~図27は、IGO膜のX線回折データ示すグラフであり、横軸は回折角(2θ(°))を示し、縦軸は回析強度(s)を示している。
図24および図25に示すように、熱処理前のIGO膜及び200℃の温度で熱処理を行なったIGO膜においては、アモルファス状態を表すブロードなX線のピークが観察された。また、図26~27に示すように、400℃または600℃の温度で熱処理を行なったIGO膜においては、六方晶構造のピークとIn2O3ビックスバイト構造のピークとが観察された。この観察結果より、400℃~600℃の温度で熱処理を行うことにより、IGO膜中の結晶構造は、六方晶構造を有するIn2O3なる組成の結晶を含むものになることがわかる。
Claims (26)
- 基板上に、化合物半導体からなるn型半導体層、発光層及びp型半導体層がこの順で積層され、さらに、導電型透光性電極からなる正極及び導電型電極からなる負極を備えてなる化合物半導体発光素子であって、
前記正極をなす導電型透光性電極が、六方晶構造を有するIn2O3なる組成の結晶を含む透明導電膜であることを特徴とする化合物半導体発光素子。 - 前記透明導電膜内におけるキャリアの移動度が30cm2/V・sec以上であることを特徴とする請求項1に記載の化合物半導体発光素子。
- 前記透明導電膜内におけるキャリアのキャリア濃度が1×1020~5×1021cm-3の範囲であることを特徴とする請求項1に記載の化合物半導体発光素子。
- 前記透明導電膜のシート抵抗が50Ω/sq以下であることを特徴とする請求項1に記載の化合物半導体発光素子。
- 前記透明導電膜の厚さが35nm~10000nm(10μm)の範囲であることを特徴とする請求項1に記載の化合物半導体発光素子。
- 前記透明導電膜の表面に凹凸加工がなされていることを特徴とする請求項1に記載の化合物半導体発光素子。
- 前記透明導電膜の表面に複数個の独立した凹部が形成されていることを特徴とする請求項6に記載の化合物半導体発光素子。
- 前記透明導電膜の凹部の合計面積が、前記透明導電膜全体の面積に対する割合で1/4~3/4の範囲であることを特徴とする請求項7に記載の化合物半導体発光素子。
- 前記透明導電膜の凹部における前記透明導電膜の厚さが、凸部における前記透明導電膜の厚さの1/2以下であることを特徴とする請求項6に記載の化合物半導体発光素子。
- 前記透明導電膜が、IZO膜、ITO膜、IGO膜のいずれかであることを特徴とする請求項1に記載の化合物半導体発光素子。
- 前記透明導電膜が、IZO膜であり、 前記IZO膜中のZnO含有量が1~20質量%の範囲であることを特徴とする請求項1に記載の化合物半導体発光素子。
- 前記化合物半導体が、窒化ガリウム系化合物半導体であることを特徴とする請求項1に記載の化合物半導体発光素子。
- 前記導電型透光性電極からなる正極が前記p型半導体層上に設けられ、前記導電型電極からなる負極が前記n型半導体層上に設けられていることを特徴とする請求項1に記載の化合物半導体発光素子。
- 少なくとも下記(a)~(d)に示す各工程を含むことを特徴とする化合物半導体発光素子の製造方法。
(a)基板上に、化合物半導体からなるn型半導体層、発光層及びp型半導体層をこの順で積層して半導体ウェーハを作製する半導体層形成工程、
(b)前記p型半導体層にアモルファス状の透明導電膜を積層する導電型透光性電極積層工程、
(c)前記透明導電膜を所定形状にエッチングするエッチング工程、及び、
(d)エッチングされた前記透明導電膜に対して、300~800℃の温度範囲で保持時間を制御しながら熱処理を行なうことにより、前記透明導電膜を、六方晶構造を有するIn2O3なる組成の結晶を含み、且つ、膜内におけるキャリアの移動度が30cm2/V・sec以上の特性に制御する熱処理工程。 - 前記透明導電膜が、IZO膜、ITO膜、IGO膜のいずれかであることを特徴とする請求項14に記載の化合物半導体発光素子の製造方法。
- 前記(d)に示す熱処理工程は、前記透明導電膜に対して、300~800℃の温度範囲で保持時間を制御しながら熱処理を行なうことにより、前記透明導電膜を、六方晶構造を有するIn2O3なる組成の結晶を含み、且つ、膜内におけるキャリアの移動度が30~100cm2/V・secの範囲の特性に制御することを特徴とする請求項14に記載の化合物半導体発光素子の製造方法。
- 前記(b)に示す導電型透光性電極積層工程は、スパッタリング法によって前記透明導電膜を積層することを特徴とする請求項14に記載の化合物半導体発光素子の製造方法。
- 前記化合物半導体が窒化ガリウム系化合物半導体であることを特徴とする請求項14に記載の化合物半導体発光素子の製造方法。
- 前記透明導電膜を、前記p型半導体層上に積層して形成することを特徴とする請求項14に記載の化合物半導体発光素子の製造方法。
- 請求項14乃至19の何れか1項に記載の製造方法によって製造される化合物半導体発光素子。
- 少なくとも六方晶構造を有するIn2O3なる組成の結晶を含む透明導電膜からなり、且つ、膜内におけるキャリアの移動度が30cm2/V・sec以上であることを特徴とする化合物半導体発光素子用導電型透光性電極。
- 膜内におけるキャリアの移動度が30~100cm2/V・secの範囲であることを特徴とする請求項21に記載の化合物半導体発光素子用導電型透光性電極。
- 膜内のキャリア濃度が1×1020~5×1021cm-3の範囲であることを特徴とする請求項21に記載の化合物半導体発光素子用導電型透光性電極。
- 請求項1乃至13又は請求項20の何れか1項に記載の化合物半導体発光素子が備えられてなるランプ。
- 請求項24に記載のランプが組み込まれてなる電子機器。
- 請求項25に記載の電子機器が組み込まれてなる機械装置。
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP09704571.0A EP2242118B1 (en) | 2008-01-24 | 2009-01-23 | Compound semiconductor light emitting element and manufacturing method for same, conductive translucent electrode for compound semiconductor light emitting element, lamp, electronic device, and mechanical apparatus |
CN2009801103360A CN101978514B (zh) | 2008-01-24 | 2009-01-23 | 化合物半导体发光元件及其制造方法、化合物半导体发光元件用导电型透光性电极、灯、电子设备以及机械装置 |
US12/864,440 US8368103B2 (en) | 2008-01-24 | 2009-01-23 | Compound semiconductor light-emitting element and method of manufacturing the same, conductive translucent electrode for compound semiconductor light-emitting element, lamp, electronic device, and mechanical apparatus |
Applications Claiming Priority (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2008-014232 | 2008-01-24 | ||
JP2008014232 | 2008-01-24 | ||
JP2008068076 | 2008-03-17 | ||
JP2008-068076 | 2008-03-17 | ||
JP2008273092A JP2009260237A (ja) | 2008-01-24 | 2008-10-23 | 化合物半導体発光素子及びその製造方法、化合物半導体発光素子用導電型透光性電極、ランプ、電子機器並びに機械装置 |
JP2008-273092 | 2008-10-23 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2009093683A1 true WO2009093683A1 (ja) | 2009-07-30 |
Family
ID=40901187
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2009/051062 WO2009093683A1 (ja) | 2008-01-24 | 2009-01-23 | 化合物半導体発光素子及びその製造方法、化合物半導体発光素子用導電型透光性電極、ランプ、電子機器並びに機械装置 |
Country Status (7)
Country | Link |
---|---|
US (1) | US8368103B2 (ja) |
EP (1) | EP2242118B1 (ja) |
JP (1) | JP2009260237A (ja) |
KR (1) | KR101151158B1 (ja) |
CN (1) | CN101978514B (ja) |
TW (1) | TWI472055B (ja) |
WO (1) | WO2009093683A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2011086855A (ja) * | 2009-10-19 | 2011-04-28 | Showa Denko Kk | 半導体発光素子の製造方法 |
Families Citing this family (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR101481855B1 (ko) * | 2008-03-06 | 2015-01-12 | 스미토모 긴조쿠 고잔 가부시키가이샤 | 반도체 발광소자, 반도체 발광소자의 제조방법 및 이 반도체 발광소자를 사용한 램프 |
JP5036840B2 (ja) * | 2010-03-25 | 2012-09-26 | 株式会社東芝 | 発光素子 |
JP5381853B2 (ja) * | 2010-03-26 | 2014-01-08 | 豊田合成株式会社 | 半導体発光素子 |
JP5433507B2 (ja) * | 2010-06-17 | 2014-03-05 | 出光興産株式会社 | 半導体発光素子 |
US9178116B2 (en) | 2010-06-25 | 2015-11-03 | Toyoda Gosei Co. Ltd. | Semiconductor light-emitting element |
JP5628615B2 (ja) * | 2010-09-27 | 2014-11-19 | スタンレー電気株式会社 | 半導体発光装置およびその製造方法 |
JP2012084667A (ja) * | 2010-10-08 | 2012-04-26 | Showa Denko Kk | 化合物半導体発光素子及びその製造方法、ランプ、電子機器並びに機械装置 |
JP5708285B2 (ja) * | 2011-06-10 | 2015-04-30 | 豊田合成株式会社 | 半導体発光素子及び半導体発光装置 |
JP5803708B2 (ja) * | 2012-02-03 | 2015-11-04 | 豊田合成株式会社 | 半導体発光素子の製造方法 |
JP2014022401A (ja) * | 2012-07-12 | 2014-02-03 | Toshiba Corp | 窒化物半導体発光素子 |
CN102983240A (zh) * | 2012-12-11 | 2013-03-20 | 东南大学 | 具有氧化锌基透明导电层的紫外发光二极管及其制备方法 |
CN103207193A (zh) * | 2013-04-23 | 2013-07-17 | 武汉科技大学 | 双层复合材料的上层材料x射线衍射谱的获取方法 |
JP6423234B2 (ja) * | 2013-11-21 | 2018-11-14 | ローム株式会社 | 半導体発光素子およびその製造方法 |
CN105728005A (zh) * | 2016-03-18 | 2016-07-06 | 济南大学 | 一种以配合物为前驱体的碳掺杂氧化铟的制备方法 |
CN109933239B (zh) * | 2019-03-12 | 2021-04-30 | 合肥鑫晟光电科技有限公司 | 透明导电结构及其制备方法、显示基板、触控基板 |
Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH08217578A (ja) | 1995-02-08 | 1996-08-27 | Idemitsu Kosan Co Ltd | 非晶質導電膜のパターニング方法 |
JP2000196152A (ja) | 1998-12-24 | 2000-07-14 | Toshiba Corp | 半導体発光素子およびその製造方法 |
JP2001089846A (ja) * | 1999-07-16 | 2001-04-03 | Hoya Corp | 低抵抗ito薄膜及びその製造方法 |
WO2001038599A1 (fr) * | 1999-11-25 | 2001-05-31 | Idemitsu Kosan Co., Ltd. | Cible de pulverisation cathodique, oxyde electro-conducteur transparent, et procede d'elaboration d'une cible de pulverisation cathodique |
JP2001215523A (ja) | 2000-11-30 | 2001-08-10 | Hitachi Ltd | 液晶表示パネル |
JP2004075427A (ja) * | 2002-08-13 | 2004-03-11 | Intertec:Kk | コランダム型結晶相を含むito膜の製造方法及び該方法で成膜した透明電極用ito膜 |
JP2004299963A (ja) * | 2003-03-31 | 2004-10-28 | Toyobo Co Ltd | In2O3材料およびそれより成る半導体装置、システム |
JP2005123501A (ja) | 2003-10-20 | 2005-05-12 | Toyoda Gosei Co Ltd | 半導体発光素子 |
JP2005197505A (ja) * | 2004-01-08 | 2005-07-21 | Kyoshin Kagi Kofun Yugenkoshi | 窒化ガリウム基iii−v族化合物半導体発光ダイオードとその製造方法 |
JP2007287845A (ja) | 2006-04-14 | 2007-11-01 | Showa Denko Kk | 半導体発光素子、半導体発光素子の製造方法およびランプ |
JP2008066276A (ja) * | 2006-08-09 | 2008-03-21 | Idemitsu Kosan Co Ltd | 酸化物導電性材料及びその製造方法 |
WO2008072681A1 (ja) * | 2006-12-11 | 2008-06-19 | Showa Denko K.K. | 化合物半導体発光素子及びその製造方法 |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1510765A (zh) | 2002-12-26 | 2004-07-07 | 炬鑫科技股份有限公司 | 氮化镓基ⅲ-ⅴ族化合物半导体led的发光装置及其制造方法 |
JP2006128227A (ja) * | 2004-10-26 | 2006-05-18 | Mitsubishi Cable Ind Ltd | 窒化物半導体発光素子 |
KR100751632B1 (ko) * | 2005-04-26 | 2007-08-22 | 엘지전자 주식회사 | 발광 소자 |
TWI291253B (en) * | 2006-04-18 | 2007-12-11 | Univ Nat Central | Light emitting diode structure |
-
2008
- 2008-10-23 JP JP2008273092A patent/JP2009260237A/ja active Pending
-
2009
- 2009-01-23 US US12/864,440 patent/US8368103B2/en active Active
- 2009-01-23 CN CN2009801103360A patent/CN101978514B/zh active Active
- 2009-01-23 KR KR1020107016335A patent/KR101151158B1/ko active IP Right Grant
- 2009-01-23 EP EP09704571.0A patent/EP2242118B1/en active Active
- 2009-01-23 WO PCT/JP2009/051062 patent/WO2009093683A1/ja active Application Filing
- 2009-01-23 TW TW98103109A patent/TWI472055B/zh active
Patent Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH08217578A (ja) | 1995-02-08 | 1996-08-27 | Idemitsu Kosan Co Ltd | 非晶質導電膜のパターニング方法 |
JP2000196152A (ja) | 1998-12-24 | 2000-07-14 | Toshiba Corp | 半導体発光素子およびその製造方法 |
JP2001089846A (ja) * | 1999-07-16 | 2001-04-03 | Hoya Corp | 低抵抗ito薄膜及びその製造方法 |
WO2001038599A1 (fr) * | 1999-11-25 | 2001-05-31 | Idemitsu Kosan Co., Ltd. | Cible de pulverisation cathodique, oxyde electro-conducteur transparent, et procede d'elaboration d'une cible de pulverisation cathodique |
JP2001215523A (ja) | 2000-11-30 | 2001-08-10 | Hitachi Ltd | 液晶表示パネル |
JP2004075427A (ja) * | 2002-08-13 | 2004-03-11 | Intertec:Kk | コランダム型結晶相を含むito膜の製造方法及び該方法で成膜した透明電極用ito膜 |
JP2004299963A (ja) * | 2003-03-31 | 2004-10-28 | Toyobo Co Ltd | In2O3材料およびそれより成る半導体装置、システム |
JP2005123501A (ja) | 2003-10-20 | 2005-05-12 | Toyoda Gosei Co Ltd | 半導体発光素子 |
JP2005197505A (ja) * | 2004-01-08 | 2005-07-21 | Kyoshin Kagi Kofun Yugenkoshi | 窒化ガリウム基iii−v族化合物半導体発光ダイオードとその製造方法 |
JP2007287845A (ja) | 2006-04-14 | 2007-11-01 | Showa Denko Kk | 半導体発光素子、半導体発光素子の製造方法およびランプ |
JP2008066276A (ja) * | 2006-08-09 | 2008-03-21 | Idemitsu Kosan Co Ltd | 酸化物導電性材料及びその製造方法 |
WO2008072681A1 (ja) * | 2006-12-11 | 2008-06-19 | Showa Denko K.K. | 化合物半導体発光素子及びその製造方法 |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2011086855A (ja) * | 2009-10-19 | 2011-04-28 | Showa Denko Kk | 半導体発光素子の製造方法 |
Also Published As
Publication number | Publication date |
---|---|
TW201001751A (en) | 2010-01-01 |
TWI472055B (zh) | 2015-02-01 |
US20100295086A1 (en) | 2010-11-25 |
CN101978514A (zh) | 2011-02-16 |
EP2242118A1 (en) | 2010-10-20 |
KR101151158B1 (ko) | 2012-06-01 |
EP2242118B1 (en) | 2017-11-22 |
EP2242118A4 (en) | 2014-09-24 |
KR20100105727A (ko) | 2010-09-29 |
US8368103B2 (en) | 2013-02-05 |
CN101978514B (zh) | 2013-05-01 |
JP2009260237A (ja) | 2009-11-05 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5201566B2 (ja) | 化合物半導体発光素子及びその製造方法 | |
WO2009093683A1 (ja) | 化合物半導体発光素子及びその製造方法、化合物半導体発光素子用導電型透光性電極、ランプ、電子機器並びに機械装置 | |
JP5068475B2 (ja) | 窒化ガリウム系化合物半導体発光素子の製造方法及び窒化ガリウム系化合物半導体発光素子、並びにランプ | |
JP5265090B2 (ja) | 半導体発光素子およびランプ | |
JP5556657B2 (ja) | Iii族窒化物半導体発光素子の製造方法及びiii族窒化物半導体発光素子、並びにランプ | |
JP5397369B2 (ja) | 半導体発光素子、該半導体発光素子の製造方法および該半導体発光素子を用いたランプ | |
KR101324442B1 (ko) | Ⅰⅰⅰ족 질화물 반도체 발광 소자 및 그의 제조 방법, 및 램프 | |
JP5047516B2 (ja) | 窒化ガリウム系化合物半導体発光素子の製造方法、窒化ガリウム系化合物半導体発光素子及びそれを用いたランプ | |
JP2012084667A (ja) | 化合物半導体発光素子及びその製造方法、ランプ、電子機器並びに機械装置 | |
JP4252622B1 (ja) | 半導体発光素子の製造方法 | |
JP2006013475A (ja) | 正極構造及び窒化ガリウム系化合物半導体発光素子 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 200980110336.0 Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 09704571 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 20107016335 Country of ref document: KR Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 12864440 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
REEP | Request for entry into the european phase |
Ref document number: 2009704571 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2009704571 Country of ref document: EP |