SiC power module with low loss and high reliability was developed by utilizing IEMOSFET and SBD. The IEMOSFET is the SiC MOSFET with high channel mobility in which the channel region is the p-type carbon-face epitaxial layer with low acceptor concentration. Elemental technologies for the high channel mobility and the high reliability of the gate oxide have been developed to realize the excellent characteristics by the IEMOSFET. The SBD was designed so as to minimize the forward voltage drops and the reverse leakage current. For the fabrication of these SiC power devices, the mass production technology such as gate oxidation, ion implantation and following activation annealing have been also developed.

A novel IGBT (insulated-gate bipolar transistor) with a monolithic overvoltage protection circuit has been developed to obtain high resistance to overvoltage stress. This device is characterized by novel integration of an avalanche diode with an IGBT structure. The conventional IGBT process can be used to fabricate this device without any additional photomasks. Since it exhibits a large safe operating area, this device can be applied not only to a soft switching application like a voltage resonant circuit but also to a hard switching application like a snubberless inductive load circuit.<>