Patent US4153486A successfully refreshed from Google Patents.
US4153486A
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Silicon tetrachloride epitaxial process for producing very sharp autodoping profiles and very low defect densities on substrates with high concentration buried impurity layers utilizing a preheating in hydrogen
Assignee: International Business Machines Corp
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Filing: 1978-06-05
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Granted: 1979-05-08
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Expires: 1998-06-05
Abstract
Abstract A method is described for depositing silicon epitaxy with very low defect levels and sharp dopant profiles which are suitable for fabricating high performance, shallow device structures. The epitaxial layer envisioned is less than about 2 microns in thickness. The layer is deposited upon a silicon substrate that has subcollector buried layers therein of above about 1x1020 N type impurity. The substrate is baked at between about 1120 DEG to 1180 DEG C. in hydrogen and then the epitaxial layer is formed using silicon tetrachloride and a temperature of between about 1000 DEG to 1100 DEG C. thereon.
Inventors
- 👤 Gurumakonda R. Srinivasan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:40
CPC Classifications
H; H10; H10P; H10P32/00; H10P32/10; H10P32/15; H10P14/00; H10P14/20; H10P14/24; H10P14/29; H10P14/2901; H10P14/2902; H10P14/2905; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; H10P14/3438; H10P14/3441; H10P14/3442; Y; Y10; Y10S; Y10S438/00; Y10S438/914; Y10S438/916; Y10S438/974
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
75 words
A method for forming an epitaxial silicon layer less than about 2 microns thick with very low electrically active defect densities and low leakage current and high MOS lifetimes comprising: bake bare silicon substrate having buried dopant layers therein and with a surface concentration above about 1×10 20 atoms per cm 3 N type at 1120° to 1180° C. in hydrogen; and grow an epitaxial layer using silicon tetrachloride between about 1000° to 1100° C.
Claim 2
Independent Claim
75 words
A method for forming an epitaxial silicon layer less than about 2 microns thick with very low electrically active defect densities and low leakage current and high MOS lifetimes comprising: bake bare silicon substrate having buried dopant layers therein and with a surface concentration above about 1×10 20 atoms per cm 3 N type at 1120° to 1180° C. in hydrogen; and grow an epitaxial layer using silicon tetrachloride between about 1000° to 1100° C.
Claim 3
Dependent Claim
20 words
The method of claim 1 wherein the growth rate of said epitaxial layer is between about 0.05 to 0.2 microns/minute.
Claim 4
Dependent Claim
16 words
The method of claim 1 wherein said bake is for between about 4 to 35 minutes.
Claim 5
Dependent Claim
29 words
The method of claim 1 wherein the carrier gas for said silicon tetrachloride is hydrogen and the gas flow is greater than about 10 cm per second linear velocity.
Claim 6
Dependent Claim
17 words
The method of claim 1 wherein arsenic is the N type impurity in said buried dopant layer.
Claim 7
Dependent Claim
17 words
The method of claim 1 wherein a arsenic dopant specie is used in forming said epitaxial layer.
Claim 8
Dependent Claim
25 words
The method of claim 1 wherein said bake temperature is about 1150° C. and the growth of said epitaxial layer is at about 1050° C.
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) | 1982-05-07 | 1982-11-06 | 1983-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-07 | 1986-11-06 | 1987-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-07 | 1990-11-06 | 1991-05-08 | $7700.00 | Window Closed / Lapsed |