US3933573A
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Aluminum nitride single crystal growth from a molten mixture with calcium nitride
Assignee: United States Department of the Air Force
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Filing: 1975-03-27
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Granted: 1976-01-20
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Expires: 1995-03-27
Abstract
Abstract A method for growing single crystals which utilizes calcium nitride as a solvent system in the molten solution growth of bulk aluminum nitride crystals.
Inventors
- 👤 Cortland O. Dugger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:14
CPC Classifications
C; C30; C30B; C30B9/00; C30B29/00; C30B29/10; C30B29/40; C30B29/403
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
97 words
A method for growing aluminum nitride single crystals which comprises the steps of forming a mixture of (a) from about 8 to 40 mole percent of aluminum nitride, and (b) from about 92 to 60 mole percent calcium nitride; heating said mixture to a temperature above about 1525°C. and maintaining said temperature for a time sufficient to form a homogeneous molten solution thereof; slowly cooling the molten solution to a temperature above its freezing point at a rate of about 0.5° to about 3.0°C./hr. in order to effect the precipitation of single crystals of said aluminum nitride.
Claim 2
Independent Claim
97 words
A method for growing aluminum nitride single crystals which comprises the steps of forming a mixture of (a) from about 8 to 40 mole percent of aluminum nitride, and (b) from about 92 to 60 mole percent calcium nitride; heating said mixture to a temperature above about 1525°C. and maintaining said temperature for a time sufficient to form a homogeneous molten solution thereof; slowly cooling the molten solution to a temperature above its freezing point at a rate of about 0.5° to about 3.0°C./hr. in order to effect the precipitation of single crystals of said aluminum nitride.
Claim 3
Dependent Claim
51 words
A method in accordance with Claim 1 wherein said mixture is composed of about 20 mole percent aluminum nitride and 80 mole percent calcium nitride; and said mixture is heated to a temperature of about 1535°C and then slowly cooled at a rate of about 3°C per hour for 30 hours.
Claim 4
Dependent Claim
49 words
A method in accordance with claim 1 wherein said mixture is composed of about 20 mole percent aluminum nitride and 80 mole percent calcium nitride; and said mixture is heated to a temperature of about 1610°C and cooled at a rate of about 3°C per hour for 30 hours.
Claim 5
Dependent Claim
48 words
A method in accordance with claim 1 wherein said mixture is composed of about 15 mole percent aluminum nitride and 85 percent calcium nitride; and said mixture is heated to a temperature of about 1550°C and cooled at a rate of about 2°C per hour for 26 hours.
References Cited (Backward Citations)
US3450499A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-01-19 | 1979-07-21 | 1980-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-19 | 1983-07-21 | 1984-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-19 | 1987-07-21 | 1988-01-20 | $7700.00 | Window Closed / Lapsed |