Non-destructive identification of edge-component burgers vector of threading dislocations in SiC wafers by birefringence imaging

Non-destructive characterization of crystalline defects in SiC wafers is important for manufacturing high-performance SiC power devices with high productivity. The present study shows that the edge component of the Burgers vector can be identified by birefringence imaging under conditions deviating slightly from the crossed-Nicols condition and by calculation of the in-plane shear stress distribution. It is also found that the combination of birefringence observation and X-ray topography allows the discrimination of the family of threading screw dislocations. The present results will further the understanding of the relationship between defect structure and the properties of SiC power devices.