Patent US4582561A successfully refreshed from Google Patents.
US4582561A
Expired / Lapsed
US
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Method for making a silicon carbide substrate
Assignee: Sharp Corp
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Filing: 1982-04-19
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Granted: 1986-04-15
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Expires: 2002-04-19
Abstract
Abstract A silicon carbide seed layer is first formed on a (111) major surface of a silicon substrate through the use of the conventional chemical vapor deposition method. The silicon carbide seed layer includes a first surface confronting the silicon substrate. The first surface shows a predetermined grain alignment oriented with the (111) major surface of the silicon substrate even though the deposition is carried out at a temperature below the melting point of the silicon substrate. Then, the silicon substrate is melted so that the first surface of the silicon carbide seed layer is exposed to the molten silicon including a carbon source therein. In this way, a second silicon carbide layer is formed on the first surface of the silicon carbide seed layer through the use of a liquid-phase epitaxial growth method. If required, a third silicon carbide layer is formed on the second silicon carbide layer to thicken the silicon carbide substrate through the use of a conventional chemical vapor deposition method, wherein the substrate is maintained at a temperature above the melting point of silicon to ensure the high-quality crystallization.
Inventors
- 👤 Toshinori Ioku
- 👤 Takeshi Sakurai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:49
CPC Classifications
C; C30; C30B; C30B19/00; C30B11/00; C30B19/02; C30B19/04; C30B29/00; C30B29/10; C30B29/36; Y; Y10; Y10S; Y10S117/00; Y10S117/915
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
90 words
A method for fabricating a silicon carbide substrate comprising the steps of: providing a clean surface silicon base plate; depositing a silicon carbide seed layer on said clean surface silicon base plate, said silicon carbide seed layer including a first surface confronting said clean surface silicon base plate; displacing said silicon base plate; and exposing said first surface of said silicon carbide seed layer to molten silicon including carbon material therein, whereby a second silicon carbide layer is epitaxially grown on said first surface of said silicon carbide seed layer.
Claim 2
Independent Claim
90 words
A method for fabricating a silicon carbide substrate comprising the steps of: providing a clean surface silicon base plate; depositing a silicon carbide seed layer on said clean surface silicon base plate, said silicon carbide seed layer including a first surface confronting said clean surface silicon base plate; displacing said silicon base plate; and exposing said first surface of said silicon carbide seed layer to molten silicon including carbon material therein, whereby a second silicon carbide layer is epitaxially grown on said first surface of said silicon carbide seed layer.
Claim 3
Dependent Claim
25 words
The method of claim 1, wherein said silicon carbide seed layer is deposited on a (111) major surface of said clean surface silicon base plate.
Claim 4
Dependent Claim
42 words
The method of claim 2, wherein said silicon carbide seed layer includes grains well oriented in a predetermined direction defined by said (111) major surface of said clean surface silicon base plate at said first surface of said silicon carbide seed layer.
Claim 5
Dependent Claim
25 words
The method of claim 1, 2 or 3, further comprising the step of forming a third silicon carbide layer on said second silicon carbide layer.
Claim 6
Dependent Claim
33 words
The method of claim 1, 2 or 3, further comprising the step of removing said silicon carbide seed layer from said second silicon carbide layer after formation of said second silicon carbide layer.
Claim 7
Independent Claim
140 words
A method for fabricating a silicon carbide substrate comprising the steps of: disposing a clean surface silicon base plate on a graphite susceptor coded with silicon carbide; depositing a silicon carbide seed layer on said clean surface silicon base plate while said susceptor is maintained at a temperature below the melting point of said clean surface silicon base plate, said silicon carbide seed layer including a first surface confronting said clean surface silicon base plate; melting said clean surface silicon base plate by heating said susceptor above said melting point of said clean surface silicon base plate, whereby a second silicon carbide layer is liquid-phase epitaxially grown on said first surface of said silicon carbide seed layer; cooling said molten silicon, said silicon carbide seed layer and said second silicon carbide layer; and removing silicon from said silicon carbide substrate.
Claim 8
Independent Claim
140 words
A method for fabricating a silicon carbide substrate comprising the steps of: disposing a clean surface silicon base plate on a graphite susceptor coded with silicon carbide; depositing a silicon carbide seed layer on said clean surface silicon base plate while said susceptor is maintained at a temperature below the melting point of said clean surface silicon base plate, said silicon carbide seed layer including a first surface confronting said clean surface silicon base plate; melting said clean surface silicon base plate by heating said susceptor above said melting point of said clean surface silicon base plate, whereby a second silicon carbide layer is liquid-phase epitaxially grown on said first surface of said silicon carbide seed layer; cooling said molten silicon, said silicon carbide seed layer and said second silicon carbide layer; and removing silicon from said silicon carbide substrate.
Claim 9
Dependent Claim
25 words
The method of claim 6, wherein said silicon carbide seed layer is deposited on a (111) major surface of said clean surface silicon base plate.
Claim 10
Dependent Claim
42 words
The method of claim 6, wherein said silicon carbide seed layer includes grains well orientated in a predetermined direction defined by said (111) major surface of said clean surface silicon base plate at said first surface of said silicon carbide seed layer.
Claim 11
Dependent Claim
41 words
The method of claim 6, wherein said graphite susceptor is heated so that the surface thereof shows a temperature about 1500° C. while said second silicon carbide layer is epitaxilally grown on said first surface of said silicon carbide seed layer.
Claim 12
Dependent Claim
20 words
The method of claim 9, wherein said graphite susceptor is heated through the use of a radio frequency induction heating.
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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) | 1989-04-14 | 1989-10-14 | 1990-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-14 | 1993-10-14 | 1994-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-14 | 1997-10-14 | 1998-04-15 | $7700.00 | Window Closed / Lapsed |