US3765880A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ohmic contacts for gallium arsenide semiconductors
Assignee: Texas Instruments Inc
•
Filing: 1971-11-18
•
Granted: 1973-10-16
•
Expires: 1991-11-18
Abstract
Abstract An improved ohmic contact includes an alloy of a silver base material, a wetting agent and a doping agent. In a specific imbodiment the alloy includes silver, indium and zinc. The alloy does not include tin and is particularly advantageous for ohmically contacting gallium arsenide.
Inventors
- 👤 R Cox
- 👤 H Strack
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:45
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0116; C; C22; C22C; C22C5/00; C22C5/06; H01; H01B; H01B1/00; H10P; H10P95/00; Y; Y10; Y10S; Y10S148/00; Y10S148/02
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
35 words
An ohmic contact substantially free from tin consisting essentially of: a. 50 to 98 percent by weight silver; b. 0.5 to 30 percent by weight indium; and c. 0.5 to 40 percent by weight zinc.
Claim 2
Dependent Claim
15 words
An ohmic contact as set forth in claim 2 wherein said contact is substantially planar.
Claim 3
Dependent Claim
22 words
An ohmic contact as set forth in claim 3 wherein said contact is characterized by a melting point in excess of 500*C.
Claim 4
Dependent Claim
38 words
A planar ohmic contact for a body of semiconductor material, consisting essentially of: a. 50 to 98 percent by weight silver; b. 0.5 to 30 percent by weight indium; and c. 0.5 to 40 percent by weight zinc.
Claim 5
Dependent Claim
16 words
An ohmic contact as set forth in claim 5 wherein said semiconductor material comprises gallium arsenide.
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) | 1976-10-15 | 1977-04-16 | 1977-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-15 | 1981-04-16 | 1981-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-15 | 1985-04-16 | 1985-10-16 | $7700.00 | Window Closed / Lapsed |