US3845738A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vapor deposition apparatus with pyrolytic graphite heat shield
Assignee: RCA Corp
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Filing: 1973-09-12
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Granted: 1974-11-05
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Expires: 1993-09-12
Abstract
Abstract A heat shield of pyrolytic graphite is deposited around the peripheries of silicon wafers in chemical-vapor-deposition apparatus of the type wherein the wafers are heated and epitaxial layers of silicon are deposited upon the surfaces of the heated wafers. The wafers and the heat shield are disposed on a susceptor of conventional graphite. The heat shield has a C-axis along which heat conductivity is relatively much lower than in the wafers and in the susceptor, and the C-axis is disposed perpendicularly to the susceptor, whereby most of the silicon is deposited onto the wafers.
Inventors
- 👤 S Berkman
- 👤 U Roundtree
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:30
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/44; C23C16/46
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
113 words
In apparatus of the type wherein a substrate is heated in a chamber, and wherein a substance is deposited onto a surface of the heated substrate from a vapor, the improvement comprising: an inducation heater operatively associated with said chamber, a susceptor, comprising conventional graphite, dispoaed within said chamber, said substrate is a wafer of silicon and disposed on said susceptor, said substance is silicon epitaxially deposited on said surface, and said heat shield being supported on said susceptor and comprising a planar member of pyrolytic graphite having a Caxis transversely diposed with respect to said surface of said substrate and said shield having an opening there-through within which is disposed said substrate.
Claim 2
Dependent Claim
113 words
In apparatus of the type wherein a substrate is heated in a chamber, and wherein a substance is deposited onto a surface of the heated substrate from a vapor, the improvement comprising: an inducation heater operatively associated with said chamber, a susceptor, comprising conventional graphite, dispoaed within said chamber, said substrate is a wafer of silicon and disposed on said susceptor, said substance is silicon epitaxially deposited on said surface, and said heat shield being supported on said susceptor and comprising a planar member of pyrolytic graphite having a Caxis transversely diposed with respect to said surface of said substrate and said shield having an opening there-through within which is disposed said substrate.
Claim 3
Dependent Claim
127 words
In apparatus of the type wherein a substrate is heated in a chamber, and wherein a subtance is deposited onto a surface of the heated substrate from a vapor, the improvement comprising: an inducation heater operatively associated with said chamber, a susceptor comprising conventional graphite diposed within said chamber, said substrate is a wafer of silicon, said substance is the reduction product of the chemical reaction between SiC14 and H2, said heat shield being supported on said susceptor and comprising a planar member of pyrolytic graphite having a C-axis along which the heat conductivity is relatively less than in said conventional graphite, and said C-axis is substantially perpendicular to the surface of said susceptor and said shield having an opening there-through within which is disposed said substrate.
Claim 4
Dependent Claim
127 words
In apparatus of the type wherein a substrate is heated in a chamber, and wherein a subtance is deposited onto a surface of the heated substrate from a vapor, the improvement comprising: an inducation heater operatively associated with said chamber, a susceptor comprising conventional graphite diposed within said chamber, said substrate is a wafer of silicon, said substance is the reduction product of the chemical reaction between SiC14 and H2, said heat shield being supported on said susceptor and comprising a planar member of pyrolytic graphite having a C-axis along which the heat conductivity is relatively less than in said conventional graphite, and said C-axis is substantially perpendicular to the surface of said susceptor and said shield having an opening there-through within which is disposed said substrate.
Claim 5
Dependent Claim
123 words
In apparatus of the type wherein a substrate is heated in a chamber, and wherein a substance is deposited onto a surface of the heated substrate from a vapor, the improvement comprising: an inducation heater operatively associated with said chamber, a susceptor comprising conventional graphite disposed within said chamber, said heat shield comprises a sheet of pyrolytic graphite formed with a plurality of through openings therein and is diposed against said susceptor, said heat shield has a C-axis along which heat conduction is relatively less than along other axes of said heat shield, a plurality of substrates, each disposed within a separate one of said through openings, and said C-axis of said heat shield is disposed transversely to the surface of said susceptor.
Claim 6
Dependent Claim
123 words
In apparatus of the type wherein a substrate is heated in a chamber, and wherein a substance is deposited onto a surface of the heated substrate from a vapor, the improvement comprising: an inducation heater operatively associated with said chamber, a susceptor comprising conventional graphite disposed within said chamber, said heat shield comprises a sheet of pyrolytic graphite formed with a plurality of through openings therein and is diposed against said susceptor, said heat shield has a C-axis along which heat conduction is relatively less than along other axes of said heat shield, a plurality of substrates, each disposed within a separate one of said through openings, and said C-axis of said heat shield is disposed transversely to the surface of said susceptor.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-04 | 1978-05-06 | 1978-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-04 | 1982-05-06 | 1982-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-04 | 1986-05-06 | 1986-11-05 | $7700.00 | Window Closed / Lapsed |