Patent US4585906A successfully refreshed from Google Patents.
US6530990B2
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US
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Susceptor designs for silicon carbide thin films
Assignee: Wolfspeed Inc
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Filing: 2001-02-21
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Granted: 2003-03-11
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Expires: 2021-02-21
Abstract
Abstract A susceptor is disclosed for minimizing or eliminating thermal gradients that affect a substrate wafer during epitaxial growth. The susceptor comprises a first susceptor portion including a surface for receiving a semiconductor substrate wafer thereon, and a second susceptor portion facing the substrate-receiving surface and spaced from the substrate-receiving surface. The spacing is sufficiently large to permit the flow of gases therebetween for epitaxial growth on a substrate on the surface, while small enough for the second susceptor portion to heat the exposed face of a substrate to substantially the same temperature as the first susceptor portion heats the face of a substrate that is in direct contact with the substrate-receiving surface.
Inventors
- 👤 Hua-Shuang Kong
- 👤 Calvin Carter, Jr.
- 👤 Joseph Sumakeris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:39
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/44; C23C16/458; C23C16/4582; C30; C30B; C30B25/00; C30B25/02; C30B25/12
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
122 words
A method for minimizing or eliminating thermal gradients that affect a substrate during epitaxial growth, the method comprising: heating a portion of a susceptor that faces, but avoids contact with, a semiconductor substrate and that is spaced sufficiently far from the substrate to permit the flow of gases between the substrate and the susceptor portion to encourage epitaxial growth on the substrate facing the susceptor portion, while concurrently beating the wafer through direct contact with a second susceptor portion by heating the second susceptor portion upon which the wafer rests so that the exposed face of the substrate is heated to substantially the same temperature as is the face of the substrate that is in direct contact with the second susceptor portion.
Claim 2
Independent Claim
122 words
A method for minimizing or eliminating thermal gradients that affect a substrate during epitaxial growth, the method comprising: heating a portion of a susceptor that faces, but avoids contact with, a semiconductor substrate and that is spaced sufficiently far from the substrate to permit the flow of gases between the substrate and the susceptor portion to encourage epitaxial growth on the substrate facing the susceptor portion, while concurrently beating the wafer through direct contact with a second susceptor portion by heating the second susceptor portion upon which the wafer rests so that the exposed face of the substrate is heated to substantially the same temperature as is the face of the substrate that is in direct contact with the second susceptor portion.
Claim 3
Dependent Claim
35 words
A method according to claim 1 wherein the heating step comprises irradiating a susceptor that is thermally responsive to certain frequencies of the electromagnetic radiation with electromagnetic radiation within the range of those certain frequencies.
Claim 4
Dependent Claim
22 words
A method according to claim 1 and further comprising the step of directing source gases to flow between the heated susceptor portions.
Claim 5
Dependent Claim
23 words
A method according to claim 1 wherein the source gases are selected from the group consisting of silane, ethylene, propane and mixtures thereof.
Claim 6
Dependent Claim
15 words
A method according to claim 1 wherein the source gases comprise trimethyl gallium and ammonia.
Claim 7
Dependent Claim
18 words
A method according to claim 4 and further comprising the step of preparing the substrate surface for growth.
Claim 8
Dependent Claim
31 words
A method according to claim 6 wherein the substrate comprises silicon carbide, and the surface preparation comprises an oxidation step followed by a chemical etching step to remove the oxidized portion.
Claim 9
Dependent Claim
23 words
A method according to claim 6 wherein the substrate comprises silicon carbide, and the surface preparation comprises dry etching the silicon carbide surface.
Claim 10
Dependent Claim
17 words
A method according to claim 6 wherein the surface preparation comprises lapping and polishing the substrate surface.
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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) | 2006-03-10 | 2006-09-09 | 2007-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-03-10 | 2010-09-09 | 2011-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-03-10 | 2014-09-09 | 2015-03-11 | $7700.00 | Window Closed / Lapsed |