US4632712A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reducing dislocations in semiconductors utilizing repeated thermal cycling during multistage epitaxial growth
Assignee: Massachusetts Institute of Technology
•
Filing: 1984-12-04
•
Granted: 1986-12-30
•
Expires: 2004-12-04
Abstract
Abstract Dislocation densities are reduced in growing semiconductors from the vapor phase by employing a technique of interrupting growth, cooling the layer so far deposited, and then repeating the process until a high quality active top layer is achieved. The method of interrupted growth, coupled with thermal cycling, permits dislocations to be trapped in the initial stages of epitaxial growth.
Inventors
- 👤 John C. C. Fan
- 👤 Bor-Yeu Tsaur
- 👤 Ronald P. Gale
- 👤 Frances M. Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:07
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/20; H10P14/34; H10P14/3402; H10P14/3424; H10P14/3432; H10P14/29; H10P14/2901; H10P14/2902; H10P14/2905; H10P14/2907; H10P14/2909; H10P14/32; H10P14/3202; H10P14/3204; H10P14/3211; H10P14/3414; H10P14/3418; H10P14/3421; Y; Y10; Y10S; Y10S148/00; Y10S148/003; Y10S148/025; Y10S148/097; Y10S438/00; Y10S438/933
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
97 words
A method of forming a semiconductor material as an epitaxial layer upon a dissimilar substrate with a reduced number of dislocations in the material, the method comprising: (a) depositing from a vapor phase a portion of the material upon the substrate; (b) changing the temperature of the deposited portion without substantial melting or plastic deformation of the deposited portion to induce stress therein and thereby trap dislocations; (c) depositing another portion of the material; and (d) repeating the steps of changing the temperature and depositing further portions of the material until a reduction in dislocations is achieved.
Claim 2
Independent Claim
97 words
A method of forming a semiconductor material as an epitaxial layer upon a dissimilar substrate with a reduced number of dislocations in the material, the method comprising: (a) depositing from a vapor phase a portion of the material upon the substrate; (b) changing the temperature of the deposited portion without substantial melting or plastic deformation of the deposited portion to induce stress therein and thereby trap dislocations; (c) depositing another portion of the material; and (d) repeating the steps of changing the temperature and depositing further portions of the material until a reduction in dislocations is achieved.
Claim 3
Dependent Claim
29 words
The method of claim 1 wherein the method further comprises first coating the substrate with a coating to further insulate the forming material from the effects of substrate lattice.
Claim 4
Dependent Claim
25 words
The method of claim 1 wherein the step of depositing the material on the dissimilar substrate further comprises depositing the material on a silicon substrate.
Claim 5
Dependent Claim
22 words
The method of claim 3 where the step of depositing the material further comprises depositing a III--V compound onto the silicon substrate.
Claim 6
Dependent Claim
31 words
The method of claim 4 wherein the step of depositing a III--V compound further comprises depositing a compound chosen from the group of GaAs, GaAlAs, and GaAsP onto the silicon substrate.
Claim 7
Dependent Claim
22 words
The method of claim 3 wherein the step of depositing the material further comprises depositing a II--VI compound onto the silicon substrate.
Claim 8
Dependent Claim
20 words
The method of claim 6 wherein the step of depositing the material further comprises depositing CdTe onto the silicon substrate.
Claim 9
Dependent Claim
25 words
The method of claim 1 wherein the step of depositing a material on the dissimilar substrate further comprises depositing the material onto an InP substrate.
Claim 10
Dependent Claim
31 words
The method of claim 1 wherein the step of depositing the material further comprises depositing a material chosen from the group of GaP, GaAs, Ge and Si onto the InP substrate.
Claim 11
Dependent Claim
22 words
The method of claim 2 wherein the step of first coating the substrate further comprises coating the substrate with a germanium coating.
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) | 1989-12-29 | 1990-06-30 | 1990-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-29 | 1994-06-30 | 1994-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-29 | 1998-06-30 | 1998-12-30 | $7700.00 | Window Closed / Lapsed |