Patent US3686698A successfully refreshed from Google Patents.
US3686698A
Expired / Lapsed
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A multiple alloy ohmic contact for a semiconductor device
Assignee: Hitachi Ltd
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Filing: 1970-12-24
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Granted: 1972-08-29
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Expires: 1990-12-24
Abstract
Abstract A protruding ohmic contact on a P type or N type semiconductor region is made by depositing an alloy of gold and a conductivity type impurity on the P type or N type region, which is heated up to a eutectic temperature of gold and the semiconductor material and thereafter depositing silver on the alloy contact; the conductivity type impurity used is such as produces the same conductivity type as that of the semiconductor region.
Inventors
- 👤 Kenji Akeyama
- 👤 Norimasa Miyamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:26
CPC Classifications
H; H10; H10P; H10P95/00; H10D; H10D99/00; H10W; H10W20/00; H10W20/40; H10W20/41; H10W20/44; H10W20/4403; H10W20/4432; H10W20/4435; H10W72/00; H10W72/20; H10W72/241; H10W72/242
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
29 words
The semiconductor device according to claim 1, wherein said gallium is included in said alloy contact within a range of about 0.1 to about 10.0 per cent by weight.
Claim 2
Dependent Claim
29 words
The semiconductor device according to claim 1, wherein said gallium is included in said alloy contact within a range of about 0.8 to about 1.0 per cent by weight.
Claim 3
Dependent Claim
158 words
A semiconductor diode comprising a semiconductor substrate of an N conductivity type, a semiconductor region of a P conductivity type formed in a major surface of said semiconductor substrate, a first alloy contact consisting essentially of gold and gallium formed on said semiconductor region, said gallium being included in said first alloy contact within a range of about 0.1 to about 10.0 per cent by weight, a first eutectic alloy layer of the semiconductor material and gold including gallium formed between said first alloy contact and said semiconductor region, a second alloy contact consisting essentially of gold and antimony formed on said semiconductor substrate, where said first alloy contact was not formed, said antimony being included in said second alloy contact within a range of about 0.1 to about 10.0 per cent by weight, and a second eutectic alloy layer of said semiconductor material and gold including antimony formed bEtween said second alloy contact and said semiconductor substrate.
Claim 4
Dependent Claim
31 words
A semiconductor diode according to claim 4, further comprising a silver layer formed on said first alloy contact and a bump contact consisting essentially of silver formed on said silver layer.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-29 | 1976-02-28 | 1976-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-29 | 1980-02-28 | 1980-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-29 | 1984-02-28 | 1984-08-29 | $7700.00 | Window Closed / Lapsed |