Patent US4113547A successfully refreshed from Google Patents.
US4113547A
Expired / Lapsed
US
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Formation of epitaxial layers on substrate wafers utilizing an inert heat radiation ring to promote uniform heating
Assignee: AT&T Inc
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Filing: 1977-11-21
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Granted: 1978-09-12
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Expires: 1997-11-21
Abstract
Abstract A method is described for growing epitaxial layers of material on monocrystalline substrates, chiefly silicon, which are substantially free of slip dislocations. The method involves placing an encircling ring of inert, heat resistant material around the rim of the substrate and over the peripheral surface of the substrate to suppress radiation from the peripheral portion of the wafer. The generation of slip dislocations is inhibited because heat is more uniformly distributed throughout the wafer.
Inventors
- 👤 Lewis Emanuel Katz
- 👤 Carl Lewis Paulnack
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:20
CPC Classifications
C; C30; C30B; C30B25/00; C30B25/02; C30B25/04; C30B25/12
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
130 words
A method of suppressing slip dislocations in an epitaxial film grown by vapor deposition on a major surface of a semiconductor wafer by affecting the radiation of heat from portions of the wafer comprising; (a) mounting the wafer on the surface of a susceptor member in an epitaxial reactor, (b) heating the reactor including the wafer to an elevated temperature, (c) depositing a film of epitaxial semiconductor material on the major surface of the wafer, and (d) reducing the emission of heat from the rim and peripheral surface portions of the wafer by encircling the wafer with a ring of inert material which encloses both the rim and the peripheral portion of the major surface without touching the wafer, thereby to produce a substantially uniform temperature profile across the wafer.
Claim 2
Independent Claim
130 words
A method of suppressing slip dislocations in an epitaxial film grown by vapor deposition on a major surface of a semiconductor wafer by affecting the radiation of heat from portions of the wafer comprising; (a) mounting the wafer on the surface of a susceptor member in an epitaxial reactor, (b) heating the reactor including the wafer to an elevated temperature, (c) depositing a film of epitaxial semiconductor material on the major surface of the wafer, and (d) reducing the emission of heat from the rim and peripheral surface portions of the wafer by encircling the wafer with a ring of inert material which encloses both the rim and the peripheral portion of the major surface without touching the wafer, thereby to produce a substantially uniform temperature profile across the wafer.
Claim 3
Dependent Claim
27 words
The method in accordance with claim 1 in which the material of said wafer is silicon and said elevated temperature is from about 1000° to 1300° C.
Claim 4
Dependent Claim
25 words
The method in accordance with claim 1 in which the inert material is one selected from the group consisting of silicon, graphite, and silicon carbide.
Claim 5
Dependent Claim
17 words
The method in accordance with claim 1 in which the film of epitaxial semiconductor material is silicon.
References Cited (Backward Citations)
US3359143A
Cited
US3419424A
Cited
US3574006A
Cited
US3436255A
Cited
US3539759A
Cited
US3892940A
Cited
US3845738A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-09-11 | 1982-03-13 | 1982-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-09-11 | 1986-03-13 | 1986-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-09-11 | 1990-03-13 | 1990-09-12 | $7700.00 | Window Closed / Lapsed |