BE904951A - Plaquette gaufree epitaxiale a cristaux mixtes en arseniure-phosphure de gallium. - Google Patents

Plaquette gaufree epitaxiale a cristaux mixtes en arseniure-phosphure de gallium.

Info

Publication number
BE904951A
BE904951A BE0/216802A BE216802A BE904951A BE 904951 A BE904951 A BE 904951A BE 0/216802 A BE0/216802 A BE 0/216802A BE 216802 A BE216802 A BE 216802A BE 904951 A BE904951 A BE 904951A
Authority
BE
Belgium
Prior art keywords
phosphide
layer
mixed crystals
epitaxial
gallium
Prior art date
Application number
BE0/216802A
Other languages
English (en)
Inventor
H Fujita
M Kanayama
T Okano
Original Assignee
Mitsubishi Monsanto Chem
Mitsubishi Chem Ind
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Monsanto Chem, Mitsubishi Chem Ind filed Critical Mitsubishi Monsanto Chem
Publication of BE904951A publication Critical patent/BE904951A/fr

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
    • H01L33/26—Materials of the light emitting region
    • H01L33/30—Materials of the light emitting region containing only elements of Group III and Group V of the Periodic Table
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/20—Deposition of semiconductor materials on a substrate, e.g. epitaxial growth solid phase epitaxy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02367—Substrates
    • H01L21/0237—Materials
    • H01L21/02387—Group 13/15 materials
    • H01L21/02392—Phosphides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02367—Substrates
    • H01L21/0237—Materials
    • H01L21/02387—Group 13/15 materials
    • H01L21/02395—Arsenides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02436—Intermediate layers between substrates and deposited layers
    • H01L21/02439—Materials
    • H01L21/02455—Group 13/15 materials
    • H01L21/02461—Phosphides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02436—Intermediate layers between substrates and deposited layers
    • H01L21/02439—Materials
    • H01L21/02455—Group 13/15 materials
    • H01L21/02463—Arsenides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02436—Intermediate layers between substrates and deposited layers
    • H01L21/02494—Structure
    • H01L21/02496—Layer structure
    • H01L21/02502—Layer structure consisting of two layers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02436—Intermediate layers between substrates and deposited layers
    • H01L21/02494—Structure
    • H01L21/02496—Layer structure
    • H01L21/0251—Graded layers
    • H—ELECTRICITY
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    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104—Forming layers
    • H01L21/02365—Forming inorganic semiconducting materials on a substrate
    • H01L21/02612—Formation types
    • H01L21/02617—Deposition types
    • H01L21/0262—Reduction or decomposition of gaseous compounds, e.g. CVD
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/15—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components having potential barriers, specially adapted for light emission
    • H01L27/153—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components having potential barriers, specially adapted for light emission in a repetitive configuration, e.g. LED bars
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/005—Processes
    • H01L33/0062—Processes for devices with an active region comprising only III-V compounds
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/005—Processes
    • H01L33/0062—Processes for devices with an active region comprising only III-V compounds
    • H01L33/0066—Processes for devices with an active region comprising only III-V compounds with a substrate not being a III-V compound
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S148/00—Metal treatment
    • Y10S148/041—Doping control in crystal growth
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S148/00—Metal treatment
    • Y10S148/056—Gallium arsenide
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S148/00—Metal treatment
    • Y10S148/067—Graded energy gap
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S148/00—Metal treatment
    • Y10S148/072—Heterojunctions
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S148/00—Metal treatment
    • Y10S148/097—Lattice strain and defects
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S438/00—Semiconductor device manufacturing: process
    • Y10S438/936—Graded energy gap

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Manufacturing & Machinery (AREA)
  • General Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Led Devices (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)
  • Recrystallisation Techniques (AREA)

Abstract

Plaquette gaufrée épitaxiale en cristaux mixtes d'arséniure-phosphure de gallium, comprenant un support monocristallin, une couche d'arséniure-phosphure de gallium formée sur le support et ayant un rapport de cristaux mixtes variant suivant son épaisseur (couche échelonnée), et une couche d'arséniure-phosphure de gallium formée sur la couche échelonnée et ayant un rapport constant de cristaux mixtes suivant son épaisseur (couche constante), caractérisée en ce que cette plaquette comprend, dans ou sur la couche échelonnée, au moins une région de couche échelonnée, au moins une région de couche dans laquelle le rapport des cristaux mixtes d'arséniure-phosphure de gallium varie de façon discontinue suivant l'épaisseur.
BE0/216802A 1985-06-19 1986-06-18 Plaquette gaufree epitaxiale a cristaux mixtes en arseniure-phosphure de gallium. BE904951A (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP60133554A JPS61291491A (ja) 1985-06-19 1985-06-19 りん化ひ化ガリウム混晶エピタキシヤルウエハ

Publications (1)

Publication Number Publication Date
BE904951A true BE904951A (fr) 1986-10-16

Family

ID=15107524

Family Applications (1)

Application Number Title Priority Date Filing Date
BE0/216802A BE904951A (fr) 1985-06-19 1986-06-18 Plaquette gaufree epitaxiale a cristaux mixtes en arseniure-phosphure de gallium.

Country Status (5)

Country Link
US (2) US4865655A (fr)
JP (1) JPS61291491A (fr)
KR (1) KR920007445B1 (fr)
BE (1) BE904951A (fr)
DE (1) DE3620466C3 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114079226A (zh) * 2020-08-21 2022-02-22 山东华光光电子股份有限公司 一种高均匀性高功率的激光器外延片及其制备方法

Families Citing this family (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63226918A (ja) * 1987-03-16 1988-09-21 Shin Etsu Handotai Co Ltd 燐化砒化ガリウム混晶エピタキシヤルウエ−ハ
US5068695A (en) * 1988-04-29 1991-11-26 Sri International Low dislocation density semiconductor device
US5221367A (en) * 1988-08-03 1993-06-22 International Business Machines, Corp. Strained defect-free epitaxial mismatched heterostructures and method of fabrication
US5264389A (en) * 1988-09-29 1993-11-23 Sanyo Electric Co., Ltd. Method of manufacturing a semiconductor laser device
JPH06105796B2 (ja) * 1989-05-30 1994-12-21 信越半導体株式会社 発光ダイオードおよびその製造方法
US5445897A (en) * 1989-11-22 1995-08-29 Mitsubishi Kasei Polytec Company Epitaxial wafer and process for producing the same
JPH0760903B2 (ja) * 1989-11-22 1995-06-28 三菱化学株式会社 エピタキシャルウェハ及びその製造方法
DE4011145A1 (de) * 1990-04-06 1991-10-10 Telefunken Electronic Gmbh Lumineszenz-halbleiterelement
JP3111644B2 (ja) * 1992-06-09 2000-11-27 三菱化学株式会社 りん化ひ化ガリウムエピタキシャルウエハ
JP3436379B2 (ja) * 1992-07-28 2003-08-11 三菱化学株式会社 りん化ひ化ガリウムエピタキシャルウエハ
US5435441A (en) * 1993-10-28 1995-07-25 Whirlpool Corporation Packing support for moveable articles within a refrigerator cabinet
US5448082A (en) * 1994-09-27 1995-09-05 Opto Diode Corporation Light emitting diode for use as an efficient emitter or detector of light at a common wavelength and method for forming the same
JP3341564B2 (ja) * 1996-01-12 2002-11-05 信越半導体株式会社 化合物半導体エピタキシャルウエーハ
CN1082032C (zh) * 1997-02-03 2002-04-03 中国科学技术大学 一种砷化铟、砷化镓的化学还原制备方法
KR100309402B1 (ko) * 1997-05-27 2002-03-08 와다 다다시 화합물반도체에피택셜웨이퍼의제조방법
JP3301371B2 (ja) * 1997-05-27 2002-07-15 信越半導体株式会社 化合物半導体エピタキシャルウェーハの製造方法
US6661445B2 (en) * 1998-08-31 2003-12-09 Canon Kabushiki Kaisha Exposure apparatus with an array of light emitting devices
IT1302713B1 (it) 1998-10-20 2000-09-29 Acs Dobfar Spa Sacco per conservare e trasportare prodotti sterili in polvere e performare nel sacco stesso soluzioni di tali prodotti.
WO2000025362A1 (fr) * 1998-10-23 2000-05-04 Infineon Technologies Ag Semi-conducteur de puissance et procede de fabrication associe
JP2001233698A (ja) * 2000-02-23 2001-08-28 Mitsubishi Chemicals Corp りん化ひ化ガリウム混晶エピタキシャルウエハ
US12046471B1 (en) * 2018-06-06 2024-07-23 United States Of America As Represented By The Secretary Of The Air Force Optimized thick heteroepitaxial growth of semiconductors with in-situ substrate pretreatment
CN116905090B (zh) * 2023-09-12 2023-12-01 苏州焜原光电有限公司 一种渐变磷组分磷砷化镓材料的生长方法

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3725749A (en) * 1971-06-30 1973-04-03 Monsanto Co GaAS{11 {11 {11 P{11 {11 ELECTROLUMINESCENT DEVICE DOPED WITH ISOELECTRONIC IMPURITIES
JPS5323590B2 (fr) * 1972-08-15 1978-07-15
JPS527373B2 (fr) * 1972-08-15 1977-03-02
JPS5122414B2 (fr) * 1972-08-17 1976-07-09
JPS4941279A (fr) * 1972-08-28 1974-04-18
JPS5129880B2 (fr) * 1973-03-15 1976-08-27
US3963538A (en) * 1974-12-17 1976-06-15 International Business Machines Corporation Two stage heteroepitaxial deposition process for GaP/Si
US3963539A (en) * 1974-12-17 1976-06-15 International Business Machines Corporation Two stage heteroepitaxial deposition process for GaAsP/Si LED's
JPS5856963B2 (ja) * 1977-05-06 1983-12-17 三菱化成ポリテック株式会社 電子発光化合物半導体の製造方法
JPS581539B2 (ja) * 1978-07-07 1983-01-11 三菱化成ポリテック株式会社 エピタキシヤルウエハ−
JPS5696834A (en) * 1979-12-28 1981-08-05 Mitsubishi Monsanto Chem Co Compound semiconductor epitaxial wafer and manufacture thereof
US4510515A (en) * 1981-01-28 1985-04-09 Stanley Electric Co., Ltd. Epitaxial wafer of compound semiconductor display device
US4495514A (en) * 1981-03-02 1985-01-22 Eastman Kodak Company Transparent electrode light emitting diode and method of manufacture
US4438446A (en) * 1981-05-29 1984-03-20 Bell Telephone Laboratories, Incorporated Double barrier double heterostructure laser
DE3128395A1 (de) * 1981-07-17 1983-02-03 Siemens AG, 1000 Berlin und 8000 München Lumineszenzdiode
DD205284A1 (de) * 1982-04-23 1983-12-21 Werk Fernsehelektronik Veb Epitaxieschichtanordnung fuer lichtemittierende halbleiterbauelemente und verfahren zur herstellung
US4616241A (en) * 1983-03-22 1986-10-07 The United States Of America As Represented By The United States Department Of Energy Superlattice optical device
JPS607720A (ja) * 1983-06-28 1985-01-16 Nec Corp エピタキシヤル成長方法

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114079226A (zh) * 2020-08-21 2022-02-22 山东华光光电子股份有限公司 一种高均匀性高功率的激光器外延片及其制备方法
CN114079226B (zh) * 2020-08-21 2024-01-12 山东华光光电子股份有限公司 一种高均匀性高功率的激光器外延片及其制备方法

Also Published As

Publication number Publication date
DE3620466C2 (fr) 1993-09-09
DE3620466C3 (de) 1998-04-23
US4968642A (en) 1990-11-06
JPS61291491A (ja) 1986-12-22
KR920007445B1 (ko) 1992-09-01
DE3620466A1 (de) 1987-01-02
KR870000747A (ko) 1987-02-01
JPH0581560B2 (fr) 1993-11-15
US4865655A (en) 1989-09-12

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Owner name: MITSUBISHI CHEMICAL CORPORATION

Effective date: 20000630