Optical properties of as-grown and process-induced stacking faults in 4H-SiC

We present a review of recent photoluminescence, cathodoluminescence and micro-photoluminescence studies that have been made to investigate the electronic properties of as-grown and/or process-induced stacking faults (SFs) in silicon carbide (SiC) epitaxial layers. For different polytypes and different acquisition conditions, we discuss the optical signature and compare with the results of model calculations. Since a SF is always a finite lamella of 3C or 8H polytype in a 4H or 6H matrix, we take successively into account the effect of the valence band offsets, internal polarizations and non-homogeneity of the potential wells. In the case of cathodoluminescence and micro-photoluminescence techniques, due to the higher pumping level, we show that some screening of the built-in electric field can be reached. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.