US4846927A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Czochralski method for single crystal growing of a compound semiconductor
Assignee: Shin-Etsu Handotai Co Ltd
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Filing: 1987-04-29
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Granted: 1989-07-11
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Expires: 2007-04-29
Abstract
Abstract The invention provides a method of high productivity for the preparation of a substantially dislocation-free single crystal of a compound semiconductor such as gallium arsenide by the liquid-encapsulated Czochralski method. The improvement provided by the invention comprises admixing the melt in the crucible with an additive having an equilibrium segregation coefficient K O smaller than 1.0, which is indium in the preparation of gallium arsenide single crystals, in a concentration of at least 1.0×10 21 atoms/cm 3 of the melt and rotating the crucible at an unusually high velocity of at least 40 rpm.
Inventors
- 👤 Toru Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:05
CPC Classifications
C; C30; C30B; C30B15/00; C30B29/00; C30B29/10; C30B29/40; C30B29/42
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
106 words
In a liquid-encapsulated Czochralski single crystal growing method for the preparation of a substantially dislocation-free single crystal of a compound semi-conductor wherein the crystal is formed by pulling up the crystal from a melt of the semi-conductor compound, the improvement which comprises admixing the melt with an additive having an equilibrium segregation coefficient K o smaller than 1.0 in an amount such that the concentration of the additive in the melt is at least 1.0×10 21 atoms/cm 3 and rotating the crucible containing the melt at a velocity of at least 40 rpm, while pulling up the compound at a velocity of at least 1.0 mm/hour.
Claim 2
Dependent Claim
106 words
In a liquid-encapsulated Czochralski single crystal growing method for the preparation of a substantially dislocation-free single crystal of a compound semi-conductor wherein the crystal is formed by pulling up the crystal from a melt of the semi-conductor compound, the improvement which comprises admixing the melt with an additive having an equilibrium segregation coefficient K o smaller than 1.0 in an amount such that the concentration of the additive in the melt is at least 1.0×10 21 atoms/cm 3 and rotating the crucible containing the melt at a velocity of at least 40 rpm, while pulling up the compound at a velocity of at least 1.0 mm/hour.
Claim 3
Dependent Claim
90 words
In a liquid-encapsulated Czochralski single crystal growing method for the preparation of a single crystal of gallium arsenide compound semiconductor by pulling up the crystal from a melt of gallium arsenide, the improvement which comprises admixing the melt of gallium arsenide with indium in an amount such that the concentration of indium in the melt is at least 1.0×10 21 atoms/cm 3 and rotating the crucible containing the melt of gallium arsenide at a velocity of at least 40 rpm, while using a pulling-up velocity of at least 1.0 mm/hour.
Claim 4
Dependent Claim
90 words
In a liquid-encapsulated Czochralski single crystal growing method for the preparation of a single crystal of gallium arsenide compound semiconductor by pulling up the crystal from a melt of gallium arsenide, the improvement which comprises admixing the melt of gallium arsenide with indium in an amount such that the concentration of indium in the melt is at least 1.0×10 21 atoms/cm 3 and rotating the crucible containing the melt of gallium arsenide at a velocity of at least 40 rpm, while using a pulling-up velocity of at least 1.0 mm/hour.
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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) | 1992-07-10 | 1993-01-09 | 1993-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-10 | 1997-01-09 | 1997-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-10 | 2001-01-09 | 2001-07-11 | $7700.00 | Window Closed / Lapsed |