US4069356A
Expired / Lapsed
US
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Method for rapidly forming photoconductive layers for integrated circuits
Assignee: Westinghouse Electric Corp
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Filing: 1975-12-22
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Granted: 1978-01-17
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Expires: 1995-12-22
Abstract
Abstract Photoconductive layers particularly useful with integrated circuits are directly made from compositions selected from the group consisting of zinc sulfide (ZnS), cadmium sulfide (CdS), cadmium selenide (CdSe), cadmium telluride (CdTe), zinc sulfide selenide (ZnS x Se 1-x ), and cadmium sulfide selenide (CdS x Se 1-x ), and cadmium sulfide telluride (CdS x Te 1-x ). Powders of component materials for the photoconductive layer are mixed with a copper halide powder such that the copper halide is between about 0.1 and 5.0% and preferably between about 0.1 and 2.0% by weight of the total mixture. The mixed powder then is formed into at least one pellet and the pellet used as an evaporant source for vacuum deposition of a photoconductive layer onto a prepared substrate at a rate greater than 10 nanometers/minute and preferably greater than 500 nanometers per minute. The photoconductive layer and substrate are then baked in an oxygen-rich atmosphere at a temperature between 300° and 550° C and preferably between 400° and 550° C for as short as about one minute.
Inventors
- 👤 Albert G. Fischer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:46
CPC Classifications
H; H10; H10P; H10P95/00; H10F; H10F71/00; H10F71/128; Y; Y10; Y10S; Y10S148/00; Y10S148/063; Y10S148/169; Y10S428/00; Y10S428/914; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24917; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
229 words
A method of making a photoconductive layer for a semiconductor device comprising the steps of: A. mixing at least one powder of a photoconductive material selected from the group consisting of zinc sulfide (ZnS), cadmium sulfide (CdS), cadmium selenide (CdSe), and cadium telluride (CdTe), with a copper halide powder, where the copper halide powder is between about 0.1 and 5.0% by weight of the total mixture; B. forming at least one cohesive pellet from the powdered mixture; C. disposing at least one said pellet of said powdered mixture along with a semiconductor substrate prepared for vapor deposition thereon in spaced relationship in a partial vacuum; D. evaporating material from said pellet to form a vapor and depositing said vapor on the semiconductor substrate at a rate greater than about 10 nanometers per minute to form a photoconductive layer on the semiconductor substrate, said photoconductive layer comprising at least one composition selected from the group consisting of zinc sulfide (ZnS), cadmium sulfide (CdS), cadmium selenide (CdSe), cadmium telluride (CdTe), zinc sulfide selenide (ZnS x Se 1-x ), cadmium sulfide selenide (CdS x Se 1-x ), and cadmium sulfide telluride (CdS x Te 1-x ) wherein x is greater than zero and less than one; and E. baking the photoconductive layer and substrate in an oxygen-rich atmosphere at a temperature between 300° and 550° C for about 1 to 2 minutes.
Claim 2
Independent Claim
229 words
A method of making a photoconductive layer for a semiconductor device comprising the steps of: A. mixing at least one powder of a photoconductive material selected from the group consisting of zinc sulfide (ZnS), cadmium sulfide (CdS), cadmium selenide (CdSe), and cadium telluride (CdTe), with a copper halide powder, where the copper halide powder is between about 0.1 and 5.0% by weight of the total mixture; B. forming at least one cohesive pellet from the powdered mixture; C. disposing at least one said pellet of said powdered mixture along with a semiconductor substrate prepared for vapor deposition thereon in spaced relationship in a partial vacuum; D. evaporating material from said pellet to form a vapor and depositing said vapor on the semiconductor substrate at a rate greater than about 10 nanometers per minute to form a photoconductive layer on the semiconductor substrate, said photoconductive layer comprising at least one composition selected from the group consisting of zinc sulfide (ZnS), cadmium sulfide (CdS), cadmium selenide (CdSe), cadmium telluride (CdTe), zinc sulfide selenide (ZnS x Se 1-x ), cadmium sulfide selenide (CdS x Se 1-x ), and cadmium sulfide telluride (CdS x Te 1-x ) wherein x is greater than zero and less than one; and E. baking the photoconductive layer and substrate in an oxygen-rich atmosphere at a temperature between 300° and 550° C for about 1 to 2 minutes.
Claim 3
Dependent Claim
42 words
A method of making a photoconductive layer for a semiconductor device as set forth in claim 1 wherein: the mixing step provides a powdered mixture including between about 0.1 and 2.0 percent by weight of the total mixture of copper chloride powder.
Claim 4
Dependent Claim
31 words
A method of making a photoconductive layer for a semiconductor device as set forth in claim 1 wherein: the baking step is performed at a temperature between 400° and 550° C.
Claim 5
Dependent Claim
44 words
A method for making a photoconductive layer for a semiconductor device as set forth in claim 1 wherein: the evaporation step is performed at a rate greater than about 500 nanometers/minute in a partial vacuum of less than about 1 × 10 -5 torr.
Claim 6
Dependent Claim
42 words
A method for making a photoconductive layer for a semiconductor device as set forth in claim 4 wherein: the mixing step provides a powdered mixture including between about 0.1 and 2.0 percent by weight of the total mixture of copper chloride powder.
Claim 7
Dependent Claim
31 words
A method for making a photoconductive layer for a semiconductor device as set forth in claim 5 wherein: the baking step is performed at a temperature between 400° and 550° C.
References Cited (Backward Citations)
US2936252A
Cited
US3703594A
Cited
US3592643A
Cited
US3704265A
Cited
US3743609A
Cited
US3754985A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-01-16 | 1981-07-18 | 1982-01-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-16 | 1985-07-18 | 1986-01-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-16 | 1989-07-18 | 1990-01-17 | $7700.00 | Window Closed / Lapsed |