US3634149A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing aluminium nitride crystals for semiconductor devices
Assignee: US Philips Corp
•
Filing: 1967-10-25
•
Granted: 1972-01-11
•
Expires: 1987-10-25
Abstract
Abstract A method of forming aluminum nitride single crystals of large area and silicon carbide-aluminum nitride heterojunctions using a modified Lely method. Aluminum nitride is introduced, as a vapor phase, into a furnace containing a plate-shaped monocrystal of silicon carbide at a temperature between 1800* and 2300* C. At those temperatures, aluminum nitride recrystallizes and condenses to deposit epitaxially on the silicon carbide. If the silicon carbide is of one conductivity type, the aluminum nitride can be suitably doped to be of the opposite conductivity type whereby a heterojunction is formed.
Inventors
- 👤 Wilhelmus Francisc Knippenberg
- 👤 Gerrit Verspui
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:54
CPC Classifications
C; C01; C01B; C01B21/00; C01B21/06; C01B21/072; C30; C30B; C30B25/00; C30B25/02; C30B29/00; C30B29/10; C30B29/38; Y; Y10; Y10S; Y10S117/00; Y10S117/915; Y10S148/00; Y10S148/065; Y10S148/072; Y10S148/113; Y10S148/148
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
40 words
A method as set forth in claim 1 wherein the silicon carbide monocrystal is provided by growing in the same chamber by recrystallization and condensation within a space bounded by silicon carbide and at a temperature of approximately 2,500* C.
Claim 2
Dependent Claim
25 words
A method as set forth in claim 1 for the growth of aluminum nitride crystals wherein the temperature is between 1,800* and 2, 100* C.
Claim 3
Dependent Claim
29 words
A method as set forth in claim 1 for the growth of mixed crystals of silicon carbide and aluminum nitride wherein the temperature is between 2,100* and 2,300* C.
Claim 4
Dependent Claim
24 words
A method as set forth in claim 1 wherein the gas atmosphere includes an inert gas-containing acceptor or donor impurities for the aluminum nitride.
Claim 5
Dependent Claim
21 words
A method as set forth in claim 1 wherein the silicon carbide crystal is separated from the aluminum nitride epitaxial layer.
References Cited (Backward Citations)
US3102828A
Cited
US3224913A
Cited
US3129125A
Cited
US3228756A
Cited
US3210624A
Cited
US3275415A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |