Patent US3959522A successfully refreshed from Google Patents.
US3959522A
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Method for forming an ohmic contact
Assignee: RCA Corp
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Filing: 1975-04-30
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Granted: 1976-05-25
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Expires: 1995-04-30
Abstract
Abstract Gold is deposited onto a heated surface of N type semiconductor material composed of either gallium arsenide, gallium phosphide, aluminum gallium arsenide or aluminum gallium phosphide. The surface of the gallium compound is cooled to room temperature whereupon tin is deposited onto the gold. The semiconductor material is then reheated until the tin alloys with and through the gold into the material. A solderable surface may be applied to the semiconductor material by applying a film nickel and then a film of gold onto the alloyed surface.
Inventors
- 👤 Ivan Ladany
- 👤 Donald Paul Marinelli, III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:07
CPC Classifications
H; H10; H10W; H10W99/00; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0116; Y; Y10; Y10S; Y10S148/00; Y10S148/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
75 words
A method for forming an ohmic contact to N-type semiconductor material selected from the group consisting of gallium arsenide, aluminum gallium arsenide, gallium phosphide, and aluminum gallium phosphide, said method comprising the steps of: depositing a thin layer of gold onto heated semiconductor material; cooling the semiconductor material; depositing a layer of tin onto the gold layer; and reheating the semiconductor material until the tin alloys into and through the gold into the semiconductor material.
Claim 2
Independent Claim
75 words
A method for forming an ohmic contact to N-type semiconductor material selected from the group consisting of gallium arsenide, aluminum gallium arsenide, gallium phosphide, and aluminum gallium phosphide, said method comprising the steps of: depositing a thin layer of gold onto heated semiconductor material; cooling the semiconductor material; depositing a layer of tin onto the gold layer; and reheating the semiconductor material until the tin alloys into and through the gold into the semiconductor material.
Claim 3
Dependent Claim
32 words
The method as in claim 1 including the steps of: depositing a nickel layer onto the alloyed surface of the semiconductor material; and depositing a layer of gold onto the nickel layer.
Claim 4
Dependent Claim
20 words
The method as in claim 1 wherein the semiconductor material is cooled to about room temperature during the cooling step.
Claim 5
Dependent Claim
18 words
The method as in claim 1 wherein the layers of gold and tin are deposited by evaporation techniques.
Claim 6
Dependent Claim
35 words
The method as in claim 4 wherein when gallium arsenide is selected as the semiconductor material, the gallium arsenide is heated to between 350° to 400° C during the deposition of the layer of gold.
Claim 7
Dependent Claim
19 words
The method as in claim 5 wherein during the reheating step the semiconductor material is heated to about 400°C.
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) | 1979-05-25 | 1979-11-24 | 1980-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-25 | 1983-11-24 | 1984-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-25 | 1987-11-24 | 1988-05-25 | $7700.00 | Window Closed / Lapsed |