Silicon carbide power devices: hopeful or hopeless?

Wide band gap semiconductors, such as SiC, GaN and diamond, offer the potential to overcome both the temperature and voltage blocking limitations of Si. In essence, the high voltage capability derives from the fact that the critical electric field of the material increases with band-gap whilst the high temperature capability derives from a reduction in intrinsic carrier concentration with increasing band-gap. The idealised, theoretical performance of a semiconductor material may be evaluated for a specific application using an appropriate figure of merit. Such comparisons typically yield figures showing improvements of orders of magnitude over conventional Si devices.