Abstract
Silicon carbide is one of wide bandgap semiconductors so that it is feasible to high power applications. Besides, the native oxide of silicon carbide is silicon dioxide. That makes it possible to construct MOS structure devices in SiC. However, there are carbon deposit in the interface during thermal oxidation. The deposited carbon increases interface trap density, and decreases channel mobility of MOSFETs. Some methods like changing oxidation environment and post annealing etc. improve the interface quality efficiently. In this paper, silicon dioxide are thermally grown on 4H-SiC substrate by different oxidation conditions. They are dry, wet ambient oxidation, dry ambient in alumina and iron environment, and platinum catalyzed oxidation testing oxidation. Then fabricating MOSFETs on them respectively to measure and discuss their electronic performances. Moreover, some effects of MOSFET are discussed in this work. Including threshold voltage varied by mobile charges effect and body contact position effect, channel mobility varied with elevated temperature, and leakage current comparison between these five dielectrics.