US4039357A
Expired / Lapsed
US
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Etching of III-V semiconductor materials with H2 S in the preparation of heterodiodes to facilitate the deposition of cadmium sulfide
Assignee: AT&T Inc
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Filing: 1976-08-27
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Granted: 1977-08-02
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Expires: 1996-08-27
Abstract
Abstract A hydrogen transport process for cleaning the surface of an indium or gallium based semiconductor material and for depositing n-type cadmium sulfide on the cleaned semiconductor material is disclosed. The cleaning and deposition can be accomplished in sequence or simultaneously. The process entails adding hydrogen sulfide to a hydrogen gas flow in a chemical vapor deposition process. Single crystalline photovoltaic cells of p-InP/n-CdS with a 13.5% efficiency have been reproducibly fabricated. An efficiency of 4.6% has been obtained with a thin layer polycrystalline p-InP/n-CdS cell. Additionally, a p-GaAs/n-CdS heterodiode cell has been produced.
Inventors
- 👤 Klaus Jurgen Bachmann
- 👤 Manfred Hermann Bettini
- 👤 Ernest Buehler
- 👤 Joseph Leo Shay
- 👤 Sigurd Wagner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:50
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/02; C23C16/0227; C23C16/0236; H; H10; H10D; H10D62/00; H10D62/40; H10D62/80; H10D62/82; H10F; H10F10/00; H10F10/10; H10F10/16; H10F71/00; H10P; H10P14/00; H10P14/20; H10P14/22; H10P14/29; H10P14/2901; H10P14/2907; H10P14/2909; H10P14/2911; H10P14/34; H10P14/3402; H10P14/3424; H10P14/3428; H10P14/3438; H10P14/3441; H10P14/3442; H10P50/00; H10P50/60; H10P50/64; H10P50/642; H10P50/646; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y10; Y10S; Y10S148/00; Y10S148/065
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
116 words
A hydrogen gas transport process for depositing a n-type cadmium sulfide layer on a p-type semiconductor material comprising the steps of passing a stream of hydrogen gas over a heated substrate of said p-type semiconductor material wherein heated cadmium sulfide is placed in the flow of said hydrogen gas upstream from said heated substrate characterized in that a sufficient quantity of hydrogen sulfide gas above the quantity of H 2 S present from any reaction of said cadmium sulfide with said stream of hydrogen gas is introduced to etch said p-type semiconductor material which is chosen from the group consisting essentially of gallium arsenide and indium phosphide and depositing n-type CdS on the etched semiconductor material.
Claim 2
Dependent Claim
116 words
A hydrogen gas transport process for depositing a n-type cadmium sulfide layer on a p-type semiconductor material comprising the steps of passing a stream of hydrogen gas over a heated substrate of said p-type semiconductor material wherein heated cadmium sulfide is placed in the flow of said hydrogen gas upstream from said heated substrate characterized in that a sufficient quantity of hydrogen sulfide gas above the quantity of H 2 S present from any reaction of said cadmium sulfide with said stream of hydrogen gas is introduced to etch said p-type semiconductor material which is chosen from the group consisting essentially of gallium arsenide and indium phosphide and depositing n-type CdS on the etched semiconductor material.
Claim 3
Dependent Claim
23 words
The process of claim 1 wherein said quantity of hydrogen sulfide gas is between 1 and 6 mole percent of said hydrogen gas.
Claim 4
Dependent Claim
28 words
The process of claim 1 wherein said heated cadmium sulfide is introduced into said H 2 gas after the introduction of said heated substrate and said hydrogen sulfide.
Claim 5
Dependent Claim
13 words
The process of claim 1 wherein said heated substrate is a single crystal.
Claim 6
Dependent Claim
11 words
The process of claim 1 wherein said heated substrate is polycrystalline.
Claim 7
Dependent Claim
29 words
The process of claim 5 including the step of removing the CdS coated substrate from said hydrogen gas flow and depositing additional cadmium sulfide to said n-type cadmium sulfide.
Claim 8
Dependent Claim
16 words
The process of claim 6 wherein said additional cadmium sulfide is deposited by molecular beam epitaxy.
Claim 9
Dependent Claim
126 words
A hydrogen gas transport process for depositing a n-type cadmium sulfide layer on a p-type semiconductor material selected from the group consisting essentially of gallium arsenide and indium phosphide comprising the steps of (1) passing a sufficient flow of H 2 S over said p-type semiconductor material at elevated temperature to form a layer of non-volatile sulfides of said p-type semiconductor material (2) flowing hydrogen over said layer of non-volatile sulfides at a given temperature to chemically reduce said layer of non-volatile sulfides to volatile sulfides of said p-type semiconductor material which are removed and (3) depositing a layer of CdS on said p-type semiconductor material etched by steps 1 and 2 by passing a gas stream containing CdS generating materials over said p-type semiconductor material.
Claim 10
Dependent Claim
126 words
A hydrogen gas transport process for depositing a n-type cadmium sulfide layer on a p-type semiconductor material selected from the group consisting essentially of gallium arsenide and indium phosphide comprising the steps of (1) passing a sufficient flow of H 2 S over said p-type semiconductor material at elevated temperature to form a layer of non-volatile sulfides of said p-type semiconductor material (2) flowing hydrogen over said layer of non-volatile sulfides at a given temperature to chemically reduce said layer of non-volatile sulfides to volatile sulfides of said p-type semiconductor material which are removed and (3) depositing a layer of CdS on said p-type semiconductor material etched by steps 1 and 2 by passing a gas stream containing CdS generating materials over said p-type semiconductor material.
Claim 11
Dependent Claim
112 words
A hydrogen gas transport process for depositing a n-type cadmium sulfide layer on a p-type semiconductor material comprising the steps of passing over a heated substrate of said p-type semiconductor material a stream of hydrogen gas including cadmium and a stoichiometric amount of sulfur-containing entities which can form CdS with said cadmium characterized in that sufficient quantity of hydrogen sulfide above that amount present from any reaction of said sulfur entities with said hydrogen gas is added to said stream of hydrogen gas to etch said p-type semiconductor material which is chosen from the group consisting essentially of gallium arsenide and indium phosphide and depositing n-type CdS on the etched semiconductor material.
Claim 12
Dependent Claim
112 words
A hydrogen gas transport process for depositing a n-type cadmium sulfide layer on a p-type semiconductor material comprising the steps of passing over a heated substrate of said p-type semiconductor material a stream of hydrogen gas including cadmium and a stoichiometric amount of sulfur-containing entities which can form CdS with said cadmium characterized in that sufficient quantity of hydrogen sulfide above that amount present from any reaction of said sulfur entities with said hydrogen gas is added to said stream of hydrogen gas to etch said p-type semiconductor material which is chosen from the group consisting essentially of gallium arsenide and indium phosphide and depositing n-type CdS on the etched semiconductor material.
Claim 13
Dependent Claim
25 words
The process of claim 9 wherein said quantity of hydrogen sulfide gas is between 1 and 6 mole percent of said stream of hydrogen gas.
References Cited (Backward Citations)
US3312571A
Cited
US3392069A
Cited
US3393103A
Cited
US3679502A
Cited
US3697338A
Cited
US3988172A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-01 | 1981-01-31 | 1981-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-01 | 1985-01-31 | 1985-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-01 | 1989-01-31 | 1989-08-02 | $7700.00 | Window Closed / Lapsed |