| 摘要 |
PROBLEM TO BE SOLVED: To distinguish the surface and rear surface of a rectangular nitride semiconductor substrate without relying upon the difference in surface roughness because visual distinguishment between the surface and rear surface of a conventional GaN wafer having a mirror surface and a rough rear surface based on the difference in surface roughness is difficult and the rough rear surface may cause adhesion of particles, warping, cracking or breaking. SOLUTION: In order to distinguish the surface and rear surface, long and short cuts are provided clockwise at two corners of a rectangular GaN substrate. The surface and rear surface are distinguished by providing one cut making an angle of 5°-40°at one corner, differentiating the beveling amount between the surface side and the rear surface side or writing a letter. Since the rear surface is made smoother to have a state approximate to the surface state, adhesion of particles is reduced, warping is suppressed and cracking and chipping are reduced. COPYRIGHT: (C)2005,JPO&NCIPI |
