US4447276A
Expired / Lapsed
US
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Molecular beam epitaxy electrolytic dopant source
Assignee: Post Office
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Filing: 1981-06-15
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Granted: 1984-05-08
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Expires: 2001-06-15
Abstract
Abstract A method of growing crystalline semiconductors such as GaAs is disclosed. The method involves epitaxial deposition from the vapor phase and provides dopant material such as sulphur in the form of a molecular beam. The molecular beam is developed by effusion from a knudsen cell. The difficulties previously encountered using sulphur as such a cell are counteracted by use of an electrochemical cell as the sulphur source. The technique allows complicated doping profiles to be produced.
Inventors
- 👤 Graham J. Davies
- 👤 Roger Heckingbottom
- 👤 David A. Andrews
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:32
CPC Classifications
C; C30; C30B; C30B23/00; C30B23/02; C30B29/00; C30B29/10; C30B29/40; H; H10; H10P; H10P14/00; H10P14/20; H10P14/22; H10P14/29; H10P14/2901; H10P14/2907; H10P14/2911; H10P14/34; H10P14/3402; H10P14/3414; H10P14/3421; H10P14/3438; H10P14/3441; H10P14/3442; Y; Y10; Y10S; Y10S252/00; Y10S252/95; Y10S252/951; Y10S438/00; Y10S438/914; Y10S438/925
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
104 words
A method of growing solid semiconductor material composed of group III and V elements from the vapor phase by epitaxial deposition on a substrate using one or more molecular beams formed from material in an effusion cell, including the step of: producing a beam of dopant material for said semiconductor material in an electrochemical cell within the effusion cell by applying a controlled emf to said electrochemical cell, wherein the dopant material is one of either sulphur, selenium or tellurium, and said electro-chemical cell comprises successively adjacent regions of Ag 2 X, Ag I and Ag, where X is S, Se or Te respectively.
Claim 2
Independent Claim
104 words
A method of growing solid semiconductor material composed of group III and V elements from the vapor phase by epitaxial deposition on a substrate using one or more molecular beams formed from material in an effusion cell, including the step of: producing a beam of dopant material for said semiconductor material in an electrochemical cell within the effusion cell by applying a controlled emf to said electrochemical cell, wherein the dopant material is one of either sulphur, selenium or tellurium, and said electro-chemical cell comprises successively adjacent regions of Ag 2 X, Ag I and Ag, where X is S, Se or Te respectively.
Claim 3
Dependent Claim
12 words
The method claimed in claim 1 wherein the semiconductor is gallium arsenide.
Claim 4
Dependent Claim
34 words
The method claimed in claim 1 wherein said emf applied to the electrochemical cell is varied during the deposition period to provide the grown material with varying concentrations of the dopant through its depth.
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) | 1987-05-08 | 1987-11-07 | 1988-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-08 | 1991-11-07 | 1992-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-08 | 1995-11-07 | 1996-05-08 | $7700.00 | Window Closed / Lapsed |