US3864162A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming gallium arsenide films by vacuum evaporation deposition
Assignee: Boeing North American Inc
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Filing: 1973-03-24
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Granted: 1975-02-04
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Expires: 1993-03-24
Abstract
Abstract A method utilizing vacuum evaporation techniques for growing monocrystalline films of III-V compounds such as gallium arsenide on structurally dissimilar crystalline substrates. In a preferred embodiment, a single gallium arsenide source is heated to 900*1000*C at a subatmospheric pressure of about 10 5 to 10 8 torr to evaporate gallium and arsenic therefrom for recombination on a smooth, clean single crystal sapphire ( Alpha -alumina) substrate maintained at about 580*-595*C.
Inventors
- 👤 Joseph L Kenty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:09
CPC Classifications
C; C30; C30B; C30B23/00; C30B23/02; C30B29/00; C30B29/10; C30B29/40; C30B29/42; Y; Y10; Y10S; Y10S117/00; Y10S117/901; Y10S117/902; Y10S148/00; Y10S148/15
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
96 words
A METHOD OF FORMING A LAYER OF MONOCRYSTALLINE GALLIUM ARSENIDE ON A MONOCRYSTALLINE SUBSTRATE HAVING A DISSIMILAR CRYSTAL STRUCTURE, COMPRISING: REMOVING A SUFFICIENT THICKNESS OF SUBSTRATE MATERIAL FROM AT LEAST ONE SURFACE OF THE SUBSTRATE TO DEFINE A SUBSTANTIALLY SMOOTH SURFACE; ETCHING SAID SURFACE TO DEFINE A CLEAN SURFACE FINISH; HEATING A SINGLE SOURCE OF GALLIUM ARSENIDE AT A SUBATMOSPHERIC PRESSURE OF APPROXIMATELY 10**-5 TO 10**-8 TORR TO EVAPORATE GALLIUM AND ARSENIC; AND HEATING THE SUBSTRATE AT THE SUBATMOSPHERIC PRESSURE TO A TEMPERATURE SUFFICIENT TO CONDENSE STOICHIOMETRIC GALLIUM ARSENIDE ON SAID ONE SURFACE OF SAID SUBSTRATE.
Claim 2
Independent Claim
96 words
A METHOD OF FORMING A LAYER OF MONOCRYSTALLINE GALLIUM ARSENIDE ON A MONOCRYSTALLINE SUBSTRATE HAVING A DISSIMILAR CRYSTAL STRUCTURE, COMPRISING: REMOVING A SUFFICIENT THICKNESS OF SUBSTRATE MATERIAL FROM AT LEAST ONE SURFACE OF THE SUBSTRATE TO DEFINE A SUBSTANTIALLY SMOOTH SURFACE; ETCHING SAID SURFACE TO DEFINE A CLEAN SURFACE FINISH; HEATING A SINGLE SOURCE OF GALLIUM ARSENIDE AT A SUBATMOSPHERIC PRESSURE OF APPROXIMATELY 10**-5 TO 10**-8 TORR TO EVAPORATE GALLIUM AND ARSENIC; AND HEATING THE SUBSTRATE AT THE SUBATMOSPHERIC PRESSURE TO A TEMPERATURE SUFFICIENT TO CONDENSE STOICHIOMETRIC GALLIUM ARSENIDE ON SAID ONE SURFACE OF SAID SUBSTRATE.
Claim 3
Dependent Claim
17 words
A method as defined in claim 1, wherein the substrate temperature is within the approximate range 550*-600*C.
Claim 4
Dependent Claim
17 words
A method as defined in claim 1, wherein the substrate temperature is within the approximate range 580*-595*C.
Claim 5
Dependent Claim
12 words
A method as defined in claim 1 wherein the substrate is sapphire.
Claim 6
Dependent Claim
12 words
A method as defined in claim 1 wherein the substrate is MgAl2O4.
Claim 7
Dependent Claim
12 words
A method as defined in claim 1 wherein the substrate is BeO.
Claim 8
Independent Claim
94 words
A method of forming a layer of monocrystalline gallium arsenide on a monocrystalline sapphire substrate, comprising: polishing at least a surface of the substrate; etching the polished surface to a smooth, clean finish; heating the etched surface of the substrate to a temperature of approximately 580*-595*C at a subatmospheric pressure of approximately 10 5 to 10 8 torr.; and heating a single source of gallium arsenide at the suBatmospheric pressure range and in the presence of the heated substrate to evaporate gallium and arsenic from the single source for recombination on the substrate surface.
Claim 9
Independent Claim
94 words
A method of forming a layer of monocrystalline gallium arsenide on a monocrystalline sapphire substrate, comprising: polishing at least a surface of the substrate; etching the polished surface to a smooth, clean finish; heating the etched surface of the substrate to a temperature of approximately 580*-595*C at a subatmospheric pressure of approximately 10 5 to 10 8 torr.; and heating a single source of gallium arsenide at the suBatmospheric pressure range and in the presence of the heated substrate to evaporate gallium and arsenic from the single source for recombination on the substrate surface.
Claim 10
Dependent Claim
34 words
A method of forming a layer of monocrystalline gallium arsenide on a monocrystalline sapphire substrate as defined in claim 7, wherein the single source of gallium arsenide is maintained within the temperature range 900*-1000*C.
Claim 11
Dependent Claim
44 words
A method of epitaxially forming a layer of monocrystalline gallium arsenide as defined in claim 7, wherein the deposition surface of the substrate is a (0001) plane and gallium arsenide is formed with a plane of the type (111) parallel to the deposition plane.
Claim 12
Dependent Claim
61 words
A method of forming a layer of monocrystalline gallium arsenide on a monocrystalline sapphire substrate as defined in claim 7, wherein the polishing sequence comprises polishing said surface with successively finer diamond paste to approximately 1.0 micron, then finish polishing with approximately 0.3 micron alumina, and wherein the etching step utilizes an etchant solution comprising an approximately 2:9 mixture of HF:HNO3.
References Cited (Backward Citations)
US3674552A
Cited
US3607135A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-03 | 1978-08-05 | 1979-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-03 | 1982-08-05 | 1983-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-03 | 1986-08-05 | 1987-02-04 | $7700.00 | Window Closed / Lapsed |