High temperature enhancement-mode NMOS and PMOS devices and circuits in 6H-SiC

SiC devices are capable of operating at very high temperatures, allowing placement of electronics in high temperature ambients with limited cooling. The enhancement-mode MOSFET, used extensively in analog and digital circuits, has a particular advantage for high temperature operation because of its insulated gate. Research in this area has produced SiC n-channel depletion-mode devices/circuits and n-channel enhancement-mode digital gates operating from 25 to 300/spl deg/C. In this report, we demonstrate the first p-channel enhancement-mode MOSFETs and integrated circuits with good characteristics from 25 to 500/spl deg/C. The first enhancement-mode NMOS operational amplifier has also been fabricated and tested. The limited transconductance of SiC MOSFETs makes it difficult to produce sizable voltage gains without active loads. This work is focused on solving this problem by developing a potential SiC CMOS technology.