	US 12,258,678 B2
	Gallium nitride single crystal substrate
Takashi Sato, Hitachi (JP); Tetsuji Fujimoto, Hitachi (JP); Toshio Kitamura, Hitachi (JP); and Masatomo Shibata, Hitachi (JP)
Assigned to SUMITOMO CHEMICAL COMPANY, LIMITED, Tokyo (JP)
Filed by SUMITOMO CHEMICAL COMPANY, LIMITED, Tokyo (JP)
Filed on Mar. 28, 2024, as Appl. No. 18/619,371.
Claims priority of application No. 2023-079178 (JP), filed on May 12, 2023.
Prior Publication US 2024/0376636 A1, Nov. 14, 2024
Int. Cl. B32B 3/02 (2006.01); C30B 29/40 (2006.01)

CPC C30B 29/406 (2013.01) [B32B 3/02 (2013.01)]

6 Claims

1. A gallium nitride single crystal substrate, which is a gallium nitride single crystal substrate that has a diameter of 50 mm or more and whose low index crystal plane closest to a main surface is a (0001) plane, wherein a density of etch pits when applying etching to the main surface with an alkaline etching solution is less than 1×10⁶cm⁻², and among peaks appearing in a histogram of diameters of the etch pits, when a diameter of a first peak appearing on a smallest diameter-side is a, a total number of the etch pits with a diameter exceeding 4a is 1/1000 or less of a number of etch pits forming the first peak.