US4456630A
Expired / Lapsed
US
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Method of forming ohmic contacts
Assignee: Monosolar Inc
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Filing: 1983-08-18
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Granted: 1984-06-26
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Expires: 2003-08-18
Abstract
Abstract A method of forming ohmic contacts with thin film p-type semiconductor Class II B - VI A compounds comprising etching the film surface with an acidic solution, then etching with a strong basic solution and finally depositing a conductive metal layer.
Inventors
- 👤 Bulent M. Basol
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:50
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/011; H10P; H10P50/00; H10P50/20; H10P52/00; H10P95/00; H10P95/70; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/543; Y10; Y10S; Y10S438/00; Y10S438/974
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
94 words
A method of forming ohmic contacts with thin film of a p-type semiconductor compound formed of at least one of the metal elements of Class II B of the Periodic Table of Elements and one of the non-metal elements of Class VI A of the Periodic Table of Elements comprising: (a) etching the surface of said film with an acidic solution to form a non-metal-rich surface; (b) treating the surface of the acid etched film with a strong basic solution; and (c) then depositing on said etched and treated surface a conductive metal layer.
Claim 2
Independent Claim
94 words
A method of forming ohmic contacts with thin film of a p-type semiconductor compound formed of at least one of the metal elements of Class II B of the Periodic Table of Elements and one of the non-metal elements of Class VI A of the Periodic Table of Elements comprising: (a) etching the surface of said film with an acidic solution to form a non-metal-rich surface; (b) treating the surface of the acid etched film with a strong basic solution; and (c) then depositing on said etched and treated surface a conductive metal layer.
Claim 3
Dependent Claim
16 words
A method as stated in claim 1 wherein the acidic solution is an oxidizing acidic solution.
Claim 4
Dependent Claim
23 words
A method as stated in claim 2 wherein the oxidizing acidic solution includes as an oxidizing agent, a dichromate or a peroxide compound.
Claim 5
Dependent Claim
22 words
A method as stated in claim 2 wherein the oxidizing acidic solution includes as an acid, sulfuric, nitric, hydrochloric or hydrofloric acid.
Claim 6
Dependent Claim
19 words
A method as stated in claim 1 wherein the strong basic solution comprises hydrazine or alkali metal hydroxide solution.
Claim 7
Dependent Claim
25 words
A method as stated in claim 1 wherein the conductive metal includes platinum, gold, silver, copper or alloys of one or more of said metals.
Claim 8
Dependent Claim
21 words
A method as stated in claim 1 wherein the acidic solution is a dichromate and the basic solution is a hydrazine
Claim 9
Dependent Claim
34 words
A method as stated in claim 7 wherein the dichromate is comprised of one part by volume H 2 SO 4 and one part by volume saturated K 2 Cr 2 O 7 .
References Cited (Backward Citations)
US2822250A
Cited
US2822299A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-06-26 | 1987-12-26 | 1988-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-26 | 1991-12-26 | 1992-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-26 | 1995-12-26 | 1996-06-26 | $7700.00 | Window Closed / Lapsed |