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US5228927A
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Method for heat-treating gallium arsenide monocrystals
Assignee: Shin-Etsu Handotai Co Ltd
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Filing: 1991-03-29
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Granted: 1993-07-20
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Expires: 2011-03-29
Abstract
Abstract A heat-treating method for an indium-doped dislocation-free gallium arsenide monocrystal having a low carbon concentration and grown in the Liquid Encapsulated Czochralski method, comprising a two-step heat treatment: (i) heating the monocrystal at a temperature between 1050 DEG C. and 1200 DEG C. for a predetermined time length, and cooling the monocrystal quickly; and (ii) heating the monocrystal at a temperature between 750 DEG C. and 950 DEG C. for a predetermined time length, and cooling the monocrystal quickly.
Inventors
- 👤 Yutaka Kitagawara
- 👤 Susumu Kuwahara
- 👤 Takao Takenaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:16
CPC Classifications
C; C30; C30B; C30B33/00; C30B29/00; C30B29/10; C30B29/40; C30B29/42; Y; Y10; Y10S; Y10S148/00; Y10S148/003; Y10S148/024; Y10S148/056
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
137 words
A semiconductor device made from an indium-doped dislocation-free gallium arsenide monocrystal which has a low carbon concentration of 2×10 15 cm -3 or lower and which is grown in a liquid encapsulated Czochralski method, and then subjected to a heat-treatment process which comprises the steps of: (i) heating said monocrystal to a temperature between 1050° C. and 1200° C. for at least 30 minutes; (ii) cooling said monocrystal to a temperature of 950° C. or lower at a cooling rate of from 10° C. per minute to 200° C. per minute; (iii) heating said monocrystal to a temperature between 750° C. and 950° C. for at least 30 minutes; and (iv) cooling said monocrystal to a temperature of 300° C. or lower at a cooling rate of from 10° C. per minute to 200° C. per minute.
Claim 2
Dependent Claim
137 words
A semiconductor device made from an indium-doped dislocation-free gallium arsenide monocrystal which has a low carbon concentration of 2×10 15 cm -3 or lower and which is grown in a liquid encapsulated Czochralski method, and then subjected to a heat-treatment process which comprises the steps of: (i) heating said monocrystal to a temperature between 1050° C. and 1200° C. for at least 30 minutes; (ii) cooling said monocrystal to a temperature of 950° C. or lower at a cooling rate of from 10° C. per minute to 200° C. per minute; (iii) heating said monocrystal to a temperature between 750° C. and 950° C. for at least 30 minutes; and (iv) cooling said monocrystal to a temperature of 300° C. or lower at a cooling rate of from 10° C. per minute to 200° C. per minute.
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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) | 1996-07-19 | 1997-01-18 | 1997-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-19 | 2001-01-18 | 2001-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-19 | 2005-01-18 | 2005-07-20 | $7700.00 | Window Closed / Lapsed |