US3890699A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making an ohmic contact to a semiconductor material
Assignee: United States Department of the Army
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Filing: 1974-06-04
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Granted: 1975-06-24
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Expires: 1994-06-04
Abstract
Abstract An ohmic contact to N-type gallium arsenide is made by depositing respective layers of gold, silver, and germanium on the gallium arsenide surface and alloying the three layer structure in an inert atmosphere and at a temperature in the range of 460* to 490*C for one to ten minutes.
Inventors
- 👤 Juri Vilms
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:08
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0116; H10P; H10P95/00; Y; Y10; Y10S; Y10S148/00; Y10S148/02
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
108 words
METHOD OF MAKING AN OHMIC CONTACT TO N-TYPE GALLIUM ARSENIDE INCLUDING THE STEPS OF A. DEPOSITING A LAYER OF GOLD ON THE GALLIUM ARSENIDE SURFACE, A LAYER OF SILVER ON SAID GOLD LAYER OF A GERMANIUM ON AT LEAST 0.080 MICRONS THICK, AND A LAYER OF GENERMANIUM ON SAID SILVER LAYER WHEREIN THE THREE LAYER STRUCTURE HAS THE COMPOSITION ABOUT 25 TO 35 WEIGHT PERCENT GOLD, ABOUT 35 TO 45 WEIGHT PERCENT SILVER AND ABOUT 25 TO 30 WEIGHT PERCENT GERMANIUM, AND B. ALLOYING THE THREE LAYER STRUCTURE IN AN INERT ATMOSPHERE AND AT A TEMPERATURE IN THE RANGE OF 460* TO 490*C FOR 1 TO 10 MINUTES.
Claim 2
Dependent Claim
108 words
METHOD OF MAKING AN OHMIC CONTACT TO N-TYPE GALLIUM ARSENIDE INCLUDING THE STEPS OF A. DEPOSITING A LAYER OF GOLD ON THE GALLIUM ARSENIDE SURFACE, A LAYER OF SILVER ON SAID GOLD LAYER OF A GERMANIUM ON AT LEAST 0.080 MICRONS THICK, AND A LAYER OF GENERMANIUM ON SAID SILVER LAYER WHEREIN THE THREE LAYER STRUCTURE HAS THE COMPOSITION ABOUT 25 TO 35 WEIGHT PERCENT GOLD, ABOUT 35 TO 45 WEIGHT PERCENT SILVER AND ABOUT 25 TO 30 WEIGHT PERCENT GERMANIUM, AND B. ALLOYING THE THREE LAYER STRUCTURE IN AN INERT ATMOSPHERE AND AT A TEMPERATURE IN THE RANGE OF 460* TO 490*C FOR 1 TO 10 MINUTES.
Claim 3
Dependent Claim
41 words
Method according to claim 1 wherein the gold layer has a thickness in the range of 0.068 to 0.095 microns, the silver layer a thickness of 0.080 to 0.103 microns, and the germanium layer a thickness of 0.111 to 0.133 microns.
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) | 1978-06-23 | 1978-12-23 | 1979-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-23 | 1982-12-23 | 1983-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-23 | 1986-12-23 | 1987-06-24 | $7700.00 | Window Closed / Lapsed |