Stacking fault nucleation sites in diffused 4H-SiC p-i-n diodes.

Abstract

The nucleation and development of stacking faults formed during the forward high current stress operation of 4H-SiC silicon carbide p-i-n diodes were investigated using the electron beam induced current mode of scanning electron microscopy and chemical etching in molten KOH. Two initial sources of stacking fault development were found. In addition to preexisting basal plane dislocations, localized defects in the near surface region, attributed to clusters of impurities, were found to serve as nucleation centers for stacking fault development during forward biasing of the diffused p-i-n diodes. Differences were observed in the electrical activity of stacking faults in diodes with the p+ region created by diffusion versus epitaxial growth.