US4666569A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making multilayer ohmic contact to thin film p-type II-VI semiconductor
Assignee: BP Technology Ventures Ltd
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Filing: 1986-06-02
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Granted: 1987-05-19
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Expires: 2006-06-02
Abstract
Abstract A method of making an ohmic content to a thin film of a II-VI compound semiconductor. The contact is made by etching the film with an acidic solution and thereafter treating the etched surface with an alkaline solution. A layer of copper 5 to 50 angstroms thick is deposited on the etched and treated surface and covered by a different metal. The contact may be heat treated to improve its performance.
Inventors
- 👤 Bulent M. Basol
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:35
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/60; H10D64/62; H10P; H10P14/00; H10P14/40; H10P14/46; H10P14/47
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
157 words
A method of forming an ohmic contact to a thin film of a p-type semiconductor compound formed of at least one of the metal elements of Class IIB of the Periodic Table of Elements and one of the non-metal elements of Class VIA of the Periodic Table of Elements, comprising: (a) etching the surface of a thin film of a p-type semiconductor compound formed of at least one of the metal elements of Class 11B of the Periodic Table of Elements and one of the non-metal elements of Class VIA of the Periodic Table of Elements 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; (c) depositing on said etched and treated surface a layer of copper metal having a layer thickness of from about 5 Angstroms to about 50 Angstroms; and (d) depositing on said copper layer a layer of a different metal.
Claim 2
Independent Claim
157 words
A method of forming an ohmic contact to a thin film of a p-type semiconductor compound formed of at least one of the metal elements of Class IIB of the Periodic Table of Elements and one of the non-metal elements of Class VIA of the Periodic Table of Elements, comprising: (a) etching the surface of a thin film of a p-type semiconductor compound formed of at least one of the metal elements of Class 11B of the Periodic Table of Elements and one of the non-metal elements of Class VIA of the Periodic Table of Elements 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; (c) depositing on said etched and treated surface a layer of copper metal having a layer thickness of from about 5 Angstroms to about 50 Angstroms; and (d) depositing on said copper layer a layer of a different metal.
Claim 3
Dependent Claim
25 words
The method in accordance with claim 1 wherein said depositing of said copper layer and said layer of conductive metal is performed by vapor depositing.
Claim 4
Dependent Claim
24 words
The method in accordance with claim 1 wherein said depositing of said copper layer and said layer of conductive metal is performed by electrodepositing.
Claim 5
Dependent Claim
24 words
The method in accordance with claim 1 wherein said method additionally comprises: (e) heat treating said deposited layers so as to anneal said layers.
Claim 6
Dependent Claim
23 words
The method in accordance with claim 4 wherein said layers are heat treated at a temperature between about 80° C. and 250° C.
Claim 7
Dependent Claim
30 words
The method in accordance with claim 1 wherein said different metal is selected from the group consisting of nickel, gold, silver, molybdenum, chromium, platinum, palladium, and mixtures and alloys thereof.
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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) | 1990-05-18 | 1990-11-17 | 1991-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-18 | 1994-11-17 | 1995-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-18 | 1998-11-17 | 1999-05-19 | $7700.00 | Window Closed / Lapsed |