Nondestructive defect characterization of SiC substrates and epilayers

This study presents a nondestructive and in-depth defect characterization method, based on the principle of polarized light microscopy (PLM), which can be used to quickly evaluate SiC substrates and epilayers. The developed PLM system has the capability to map, on a wafer scale, micropipes, elementary screw dislocations, and domain boundaries in SiC wafers. One unique feature of the PLM system is the ability to characterize the wafer with and without an epilayer, providing a newly found opportunity to investigate threading defect propagation in the overgrown epilayer. The correlation between SiC substrate defects and epilayer defects will be established.