Intrinsic defects in high-purity SiC

Intrinsic defects are of importance for different applications of SiC such as: the semi-insulating (SI) properties of SI substrates, the carrier lifetime of high-voltage, bipolar power devices and the colour of gemstones (Moissanites). In order to tailor the properties of the material, we need to understand the properties of the intrinsic defects, their energy positions in the bandgap, their ability to capture carriers from the bands, their formation and annealing as well as their interplay with other defects.High-purity SiC materials (doping less than 1016 cm−3) grown by high temperature chemical vapour deposition (HTCVD), physical vapour transport (PVT) and chemical vapour deposition (CVD) have been investigated by electron paramagnetic resonance (EPR), photoluminescence (PL), absorption and electrical techniques. Vacancies (VC+,VSi0), divacancies and antisite-related defects are found to be common. The present knowledge of intrinsic defects in SiC based on both experiments and on calculations will be presented as well as their influence on mainly the semi-insulating properties.