The possible use of optical stress techniques to delineate various defects in SiC wafers was demonstrated. The observed defects included micropipes, dislocations, stress striations, grain boundary or dislocation walls and regions of polytype non-uniformity. The observed dislocation density ranged from 104 to 105/cm2.

Non-Destructive Defect Delineation in SiC Wafers Based on an Optical Stress Technique. X.Ma, M.Parker, T.S.Sudarshan: Applied Physics Letters, 2002, 80[18], 3298-300