US4695869A
Expired / Lapsed
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GAAS semiconductor device
Assignee: Toshiba Corp
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Filing: 1986-07-07
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Granted: 1987-09-22
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Expires: 2006-07-07
Abstract
Abstract A GaAs semiconductor device, includes a p-type GaAs substrate, an n-type region formed in the surface area of the substrate, an ohmic contact electrode formed in ohmic contact with the n + -type region and having a layer of alloy of gold, and an interconnection electrode formed on the ohmic contact electrode and including an upper layer of aluminum and a lower layer of a metal which prevents gold from passing through it. The interconnection electrode is formed such that it covers the top and side surfaces of the ohmic contact electrode.
Inventors
- 👤 Kazuhiko Inoue
- 👤 Tatsuro Mitani
- 👤 Yoshihiro Kishita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:35
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/80; H10D62/85; H10D64/00; H10D64/60; H10D64/62; H10W; H10W20/00; H10W20/40; H10W20/41; H10W20/425; H10W72/00; H10W72/90; H10W72/951; H10W72/952
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
84 words
A GaAs semiconductor device comprising: a GaAs substrate; a plurality of ohmic contact electrodes formed on said substrate and each including a layer of alloy of gold; and a plurality of conductive members respectively formed on said ohmic contact electrodes and each including an upper layer of aluminum and a lower layer of a metal capable of preventing gold from passing therethrough, said lower layer being formed to cover completely the top and side surfaces of a corresponding one of said ohmic contact electrodes.
Claim 2
Dependent Claim
84 words
A GaAs semiconductor device comprising: a GaAs substrate; a plurality of ohmic contact electrodes formed on said substrate and each including a layer of alloy of gold; and a plurality of conductive members respectively formed on said ohmic contact electrodes and each including an upper layer of aluminum and a lower layer of a metal capable of preventing gold from passing therethrough, said lower layer being formed to cover completely the top and side surfaces of a corresponding one of said ohmic contact electrodes.
Claim 3
Dependent Claim
41 words
A GaAs semiconductor device according to claim 1, further comprising a semiconductor region of the opposite conductivity type formed in the surface area of said semiconductor substrate and said ohmic contact electrodes are formed in ohmic contact with said semiconductor region.
Claim 4
Dependent Claim
27 words
A GaAs semiconductor device according to claim 2, wherein said lower layer of said conductive members has a greater thickness than that of said ohmic contact electrode.
Claim 5
Dependent Claim
31 words
A GaAs semiconductor device according to claim 3, wherein said lower layer of said conductive members is made of a metal selected from a group consisting of titanium, molybdenum, and tantalum.
Claim 6
Dependent Claim
27 words
A GaAs semiconductor device according to claim 4, wherein each said ohmic contact electrode includes an upper layer of platimum and a lower layer of Au-Ge alloy.
Claim 7
Dependent Claim
27 words
A GaAs semiconductor device according to claim 3, wherein each said ohmic contact electrode includes an upper layer of platimum and a lower layer of Au-Ge alloy.
Claim 8
Dependent Claim
27 words
A GaAs semiconductor device according to claim 1, wherein said lower layer of said conductive members has a greater thickness than that of said ohmic contact electrode.
Claim 9
Dependent Claim
32 words
A GaAs semiconductor layer device according to claim 7, wherein said lower layer of said conductive members is made of a metal selected from a group consisting of titanium, molybdenum, and tantalum.
Claim 10
Dependent Claim
27 words
A GaAs semiconductor device according to claim 8, wherein each said ohmic contact electrode includes an upper layer of platimum and a lower layer of Au-Ge alloy.
Claim 11
Dependent Claim
45 words
A GaAs semiconductor device according to claim 1, wherein a semiconductor region is formed in the surface area of said semiconductor substrate and said ohmic contact electrode is disposed on said semiconductor substrate and semiconductor region, and formed in ohmic contact with said semiconductor region.
Claim 12
Dependent Claim
147 words
A GaAs semiconductor device comprising: a GaAs substrate; n + -source and drain regions formed in the surface area of said GaAs substrate; a channel region formed between said n + -type source and drain regions in the surface area of said GaAs substrate; a gate structure formed on said channel region; first and second ohmic contact electrodes respectively formed in ohmic contact with said n + -type source and drain regions, and each including a layer of alloy of gold; first and second conductive members respectively formed on said first and second ohmic contact electrodes without touching said channel region and each including an upper layer of aluminum and a lower layer of metal capable of preventing gold from passing therethrough, said lower layer being formed to cover completely the top and side surfaces of a corresponding one of said first and second ohmic contact electrodes.
Claim 13
Dependent Claim
147 words
A GaAs semiconductor device comprising: a GaAs substrate; n + -source and drain regions formed in the surface area of said GaAs substrate; a channel region formed between said n + -type source and drain regions in the surface area of said GaAs substrate; a gate structure formed on said channel region; first and second ohmic contact electrodes respectively formed in ohmic contact with said n + -type source and drain regions, and each including a layer of alloy of gold; first and second conductive members respectively formed on said first and second ohmic contact electrodes without touching said channel region and each including an upper layer of aluminum and a lower layer of metal capable of preventing gold from passing therethrough, said lower layer being formed to cover completely the top and side surfaces of a corresponding one of said first and second ohmic contact electrodes.
Claim 14
Dependent Claim
35 words
A GaAs semiconductor device according to claim 11, wherein said lower layer of each of said first and second conductive members has a greater thickness than that of said first and second ohmic contact electrodes.
Claim 15
Dependent Claim
35 words
A GaAs semiconductor device according to claim 12, wherein said lower layer of each said first and second conductive members is made of a metal selected from a group consisting of titanium, molybdenum, and tantalum.
Claim 16
Dependent Claim
31 words
A GaSa semiconductor device according to claim 13, wherein each of said first and second ohmic contact electrodes includes an upper layer of platinum and a lower layer of Au-Ge alloy.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-09-21 | 1991-03-23 | 1991-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-09-21 | 1995-03-23 | 1995-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-09-21 | 1999-03-23 | 1999-09-22 | $7700.00 | Window Closed / Lapsed |