US 12,104,276 B2
Ga2O3-based single crystal substrate
Kohei Sasaki, Tokyo (JP)
Assigned to TAMURA CORPORATION, Tokyo (JP)
Filed by TAMURA CORPORATION, Tokyo (JP)
Filed on Apr. 21, 2021, as Appl. No. 17/236,564.
Application 17/236,564 is a continuation of application No. 15/502,008, abandoned, previously published as PCT/JP2015/072334, filed on Aug. 6, 2015.
Claims priority of application No. 2014-161760 (JP), filed on Aug. 7, 2014.
Prior Publication US 2021/0238766 A1, Aug. 5, 2021
Int. Cl. H01L 21/321 (2006.01); C30B 29/16 (2006.01); C30B 33/00 (2006.01)
CPC C30B 29/16 (2013.01) [C30B 33/00 (2013.01)] 2 Claims
OG exemplary drawing
 
1. A method of providing a Ga2O3-based single crystal substrate having cracks at a crack density of less than 0.05 cracks/cm, comprising the steps of:
preparing a Ga2O3-based single crystal substrate, wherein a plane as a principal surface is rotated 10 to 150° about [010] axis with respect to a (100) plane, and wherein a direction of rotation from the (100) plane to a (001) plane via a (101) plane is defined as positive;
polishing the plane rotated an angle in a scope of 10 to 150° by using diamond abrasive grains; and
subsequently polishing the plane rotated the angle in the scope of 10 to 150° by CMP (Chemical Mechanical Planarization) process;
wherein the cracks are such cracks that occurred extending along a [010] direction on the plane due to polishing using the diamond abrasive grains, and were not eliminated by the CMP process.
 
2. A method of providing a Ga2O3-based single crystal substrate having cracks at a crack density of less than 0.05 cracks/cm and no latent scratch, comprising the steps of:
preparing a Ga2O3-based single crystal substrate, wherein a plane as a principal surface is rotated 10 to 70° or 100 to 150° about [010] axis with respect to a (100) plane, and wherein a direction of rotation from the (100) plane to a (001) plane via a (101) plane is defined as positive;
polishing the plane rotated an angle in a scope of 10 to 70° or 100 to 150° by using diamond abrasive grains; and
subsequently polishing the plane rotated the angle in the scope of 10 to 70° or 100 to 150° by CMP (Chemical Mechanical Planarization) process;
wherein the cracks are such cracks that occurred extending along a [010] direction on the plane due to polishing using the diamond abrasive grains, and were not eliminated by the CMP process.