US4869776A
Expired / Lapsed
US
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Method for the growth of a compound semiconductor crystal
Assignee: Sharp Corp
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Filing: 1987-07-28
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Granted: 1989-09-26
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Expires: 2007-07-28
Abstract
Abstract A method for the growth of a compound semiconductor crystal using the sublimation method or the halogen transportation method, comprising maintaining the temperature of a limited portion of the crystal, which has just begun to grow, at a higher level than that of the crystal growth temperature, thereby attaining control of the crystallinity of the crystal at the initial growth stage, and an apparatus for the said method.
Inventors
- 👤 Masahiko Kitagawa
- 👤 Yoshitaka Tomomura
- 👤 Satoshi Yamaue
- 👤 Shigeo Nakajima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:22
CPC Classifications
C; C30; C30B; C30B23/00; C30B23/02; C30B23/06; C30B23/002; C30B29/00; C30B29/10; C30B29/46; C30B29/48
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
147 words
A method for the growth of a compound semiconductor crystal using the sublimation method or the halogen transportation method, consisting essentially of maintaining the temperature of a limited portion of the crystal, which has just begun to grow, at a higher level than that of the crystal growth temperature, thereby attaining control of the crystallinity of the crystal at the initial growth stage, wherein temperature control is performed using a fixed first heater which creates a temperature distribution over the whole area within a crystal growth vessel including both a crystal growth region and a crystal material storage region; and a moveable second heater which is positioned at the desired portion of the crystal that has just begun to grow and controls the temperature of a limited area within said crystal growth vessel corresponding to the desired portion of the crystal that has just begun to grow.
Claim 2
Independent Claim
147 words
A method for the growth of a compound semiconductor crystal using the sublimation method or the halogen transportation method, consisting essentially of maintaining the temperature of a limited portion of the crystal, which has just begun to grow, at a higher level than that of the crystal growth temperature, thereby attaining control of the crystallinity of the crystal at the initial growth stage, wherein temperature control is performed using a fixed first heater which creates a temperature distribution over the whole area within a crystal growth vessel including both a crystal growth region and a crystal material storage region; and a moveable second heater which is positioned at the desired portion of the crystal that has just begun to grow and controls the temperature of a limited area within said crystal growth vessel corresponding to the desired portion of the crystal that has just begun to grow.
Claim 3
Dependent Claim
52 words
A method according to claim 1, wherein transporting mediums used in said halogen transportation method are halogen compounds made of a metallic or submetallic element and a halogen element, said halogen compounds being chemically stable at room temperature and being decomposed at a temperature that is lower than the crystal growth temperature.
Claim 4
Dependent Claim
55 words
A method according to claim 1, wherein said compound semiconductor crystal is composed of group II elements and Group VI elements, said crystal growth temperature being in the range of 750° C. to 1250° C. and said temperature of a limited portion of the crystal being in the range of 755° C. to 1300° C.
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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) | 1992-09-25 | 1993-03-27 | 1993-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-25 | 1997-03-27 | 1997-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-25 | 2001-03-27 | 2001-09-26 | $7700.00 | Window Closed / Lapsed |