METHOD OF MANUFACTURING ALUMINIUM NITRIDE CRYSTALS FOR SEMICONDUCTOR DEVICES

• US 3,634,149 A
• Filed: 10/25/1967
• Issued: 01/11/1972
• Est. Priority Date: 10/25/1966
• Status: Expired due to Term

• Current Assignee: Knippenberg Wilhelmus Francisc, Verspui Gerrit
• Original Assignee: Knippenberg Wilhelmus Francisc, Verspui Gerrit
• Inventors: KNIPPENBERG WILHELMUS FRANCISC, VERSPUI GERRIT
• Application Number:
  US04/678,056
• Time in Patent Office: 1,539 Days
• US Class Current: 117/87
• CPC Class Codes: C01B 21/072 with aluminium
• CPC Class Codes: C30B 25/02 Epitaxial-layer growth
• CPC Class Codes: C30B 29/38 Nitrides
• CPC Class Codes: Y10S 117/915 Separating from substrate
• CPC Class Codes: Y10S 148/065 Gp III-V generic compounds-processing
• CPC Class Codes: Y10S 148/072 Heterojunctions
• CPC Class Codes: Y10S 148/113 Nitrides of boron or aluminum or gallium
• CPC Class Codes: Y10S 148/148 Silicon carbide

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.

Claims

2. 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.

3. 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.

4. 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.

5. 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.

6. A method as set forth in claim 1 wherein the silicon carbide crystal is separated from the aluminum nitride epitaxial layer.