Identification of a major cause of endemically poor mobilities in SiC/ SiO2 structures

Poor electron mobility at SiC/ SiO2 interfaces has long held up the development of SiC-based power devices. The mobility degradation has been attributed to defects at the interface and the oxide as in the case of the Si/ SiO2 system, but a decade of research has led only to limited improvement. Here we examine theoretical results and available experimental evidence and show that thermal oxidation generates immobile carbon di-interstitial defects inside the semiconductor substrate and that they are a major cause of the poor mobility in SiC/ SiO2 structures. © 2011 American Institute of Physics