US4062103A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for manufacturing a semiconductor device
Assignee: Toshiba Corp
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Filing: 1975-09-02
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Granted: 1977-12-13
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Expires: 1995-09-02
Abstract
Abstract A method comprises forming a Schottky barrier forming a metal layer on one surface of a gallium arsenide substrate using niobium, tantalum and/or vanadium to provide a Schottky barrier, and subjecting the Schottky barrier to heat treatment at 350° to 800° C so as to render it thermally stable.
Inventors
- 👤 Haruo Yamagishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:43
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; H10D30/67; H10D30/6729; H10D30/6737; H10D30/6738; H10D30/674; H10D30/675; H10D64/00; H10D64/01; H10D64/012; H10D64/0124; H10D64/60; H10D64/64; H10D62/00; H10D62/80; H10D62/85
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
88 words
A method for manufacturing a semiconductor device comprising the steps of: forming a Schottky barrier metal layer of niobium on one surface of a gallium arsenide substrate to provide a Schottky barrier therebetween; forming a blocking metal layer on the Schottky barrier metal layer made of at least one material selected from the group consisting of molybdenum and tungsten; forming a gold electrode layer on the blocking metal layer, and then; subjecting the Schottky barrier to heat treatment at 350° to 800° C to make it thermally stable.
Claim 2
Independent Claim
88 words
A method for manufacturing a semiconductor device comprising the steps of: forming a Schottky barrier metal layer of niobium on one surface of a gallium arsenide substrate to provide a Schottky barrier therebetween; forming a blocking metal layer on the Schottky barrier metal layer made of at least one material selected from the group consisting of molybdenum and tungsten; forming a gold electrode layer on the blocking metal layer, and then; subjecting the Schottky barrier to heat treatment at 350° to 800° C to make it thermally stable.
Claim 3
Dependent Claim
21 words
A method according to claim 1, in which said heat treating temperature is in a range of 400° to 600° C.
Claim 4
Dependent Claim
30 words
A method according to claim 1, which further includes the step of forming an ohmic electrode layer on the other surface of said gallium arsenide substrate before the heat treatment.
Claim 5
Dependent Claim
20 words
A method according to claim 3 which further includes the step of subjecting the gallium arsenide substrate to mesa etching.
Claim 6
Dependent Claim
40 words
A method according to claim 3 which further includes the step of partially removing said Schottky barrier metal layer, said blocking metal layer and said electrode layer by means of etching to reduce the Schottky barrier to a predetermined dimension.
Claim 7
Dependent Claim
20 words
A method according to claim 1 in which said Schottky barrier metal has a thickness of 1000 to 3000 A.
References Cited (Backward Citations)
US3906540A
Cited
US3886580A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-12-12 | 1981-06-13 | 1981-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-12-12 | 1985-06-13 | 1985-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-12-12 | 1989-06-13 | 1989-12-13 | $7700.00 | Window Closed / Lapsed |