Defect observation in SiC wafers by room-temperature photoluminescence mapping

We characterized SiC wafers by photoluminescence (PL) spectroscopy and mapping. Characteristic PL mapping patterns corresponded to etch-pit patterns originating from dislocations and micropipes. The intensities of the 1.3 eV band related to Si vacancies, the 0.9 eV band related to vanadium and the 1.1 eV band related to undefined UD-1 centers were decreased, increased and increased around dislocations, respectively. We believe that the variation of intensity contrast around dislocations can be ascribed to difference in the diffusivity between point defects and impurities, and in their interaction with dislocations.