METHOD OF MANUFACTURING GALLIUM NITRIDE SUBSTRATE

• US 20130260538A1
• Filed: 03/16/2013
• Published: 10/03/2013
• Est. Priority Date: 03/28/2012
• Status: Abandoned Application

• Current Assignee: Hitachi Metals (Thailand) Ltd.
• Original Assignee: Hitachi Cable Limited (Proterial Ltd.)
• Inventors: Fujikura, Hajime
• Application Number:
  US13/844,894
• Publication Number:
  US 20130260538A1
• Time in Patent Office: Days
• US Class Current: 438/478
• CPC Class Codes: C30B 29/406 Gallium nitride
• CPC Class Codes: C30B 33/10 in solutions or melts
• CPC Class Codes: H01L 21/02389 Nitrides

Abstract

A method of manufacturing a gallium nitride substrate includes machining a gallium nitride crystal, and wet-etching the gallium nitride crystal prior to the machining.

Claims

1. A method of manufacturing a gallium nitride substrate, comprising:

machining a gallium nitride crystal; and

wet-etching the gallium nitride crystal prior to the machining.

2. The method according to claim 1, wherein the gallium nitride crystal comprises an as-grown crystal or a sliced substrate formed by slicing the as-grown crystal.

3. The method according to claim 1, wherein the machining comprises a plurality of process steps, and

wherein the wet-etching is conducted before each of the plurality of process steps.

4. The method according to claim 1, wherein a surface of the gallium nitride crystal except a C-plane is wet-etched.

5. The method according to claim 1, wherein an etching amount is not less than 5 μ

m in a direction perpendicular to a surface being etched.

6. The method according to claim 1, wherein a liquid mixture of phosphoric acid and sulfuric acid is used for the wet-etching.

7. The method according to claim 6, wherein a mixture fraction of sulfuric acid to phosphoric acid is not less than 1/10 and not more than 10.

8. The method according to claim 6, wherein temperature of the liquid mixture is not less than 200°

C. and not more than 300°

C.