Electrical Properties of 4H-Silicon Carbide Complementary Metal–Oxide–Semiconductor Devices with Wet-Processed Gate Oxide

We fabricated 4H-silicon carbide (4H-SiC) complementary metal–oxide–semiconductor (CMOS) devices by wet gate oxidation processing. The wet gate oxidation was suitable for 4H-SiC p-channel MOS field-effect transistors (PMOSFETs), but resulted in poor channel properties for 4H-SiC n-channel MOSFETs (NMOSFETs). In order to improve and control the channel properties of NMOSFETs, we employed a buried channel structure within them. The transfer characteristics for a 4H-SiC CMOS inverter were investigated. The dynamic characteristics were evaluated using ring oscillators comprised of 4H-SiC CMOS inverters. The temperature dependence of the 4H-SiC CMOS devices was also investigated, and we confirmed stable operation of 4H-SiC CMOS devices at 300 °C.