Birefringence images of micropipes viewed end-on in 6H-SiC single crystals

The nature of the micropipe, a fatal defect in SiC-based device applications, is still not fully understood. In this work, the birefringence images of micropipes in 6H-SiC crystals along the c axis have been observed and simulated in detail. Based on Frank's theory, the intensity contours of birefringence images for micropipes viewed end-on in 6H-SiC crystals have been derived by considering the photoelastic anisotropy of silicon carbide. The results are in good agreement with experimental observations.