US 12,290,899 B2
Method of manufacturing gallium nitride single-crystal substrate and method of manufacturing single-crystal substrate of nitride of group 13 element in periodic table
Yuri Osumi, Higashiomi (JP)
Assigned to KYOCERA Corporation, Kyoto (JP)
Appl. No. 18/575,243
Filed by KYOCERA Corporation, Kyoto (JP)
PCT Filed Jun. 30, 2021, PCT No. PCT/JP2021/024722
§ 371(c)(1), (2) Date Dec. 28, 2023,
PCT Pub. No. WO2023/276036, PCT Pub. Date Jan. 5, 2023.
Prior Publication US 2024/0300064 A1, Sep. 12, 2024
Int. Cl. B24B 7/22 (2006.01); C30B 29/40 (2006.01); C30B 33/00 (2006.01)
CPC B24B 7/228 (2013.01) [B24B 7/22 (2013.01); C30B 29/406 (2013.01); C30B 33/00 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A method of manufacturing a gallium nitride single-crystal substrate, the method comprising:
grinding a main surface by arranging a single-crystal holder holding a gallium nitride single crystal having a semipolar plane as the main surface and a grindstone holder holding a grindstone to face each other, and pressing the gallium nitride single crystal and the grindstone against each other while rotating one or both of the gallium nitride single crystal and the grindstone, wherein
the main surface is ground to make an angle formed by a direction in which the grindstone grinds the main surface and a direction obtained by projecting a c-axis of the gallium nitride single crystal onto the main surface, to be within at least one range selected from the group consisting of ranges A, C, and E,
where range A is −45° or more and 45° or less,
range C is 55° or more and 135° or less,
range E is −135° or more and −55° or less,
where the angle is formed by a direction in which the grindstone grinds the main surface, and a direction obtained by projecting a [0001] direction of the gallium nitride single crystal onto the main surface when the main surface is a surface on a [0001] direction side, or a direction obtained by projecting a [000-1] direction of the gallium nitride single crystal onto the main surface when the main surface is a surface on a [000-1] direction side, and
an upstream side of the substrate in a rotation direction is from 0° to 180°; and a downstream side is from 0° to −180°.