Digital CMOS IC's in 6H-SiC operating on a 5-V power supply

Abstract

A CMOS technology in 6H-SiC utilizing an implanted p-well process is developed. The p-wells are fabricated by implanting boron ions into an n-type epilayer. PMOS devices are fabricated on an n-type epilayer while the NMOS devices are fabricated on implanted p-wells using a thermally grown gate oxide. The resulting NMOS devices have a threshold voltage of 3.3 V while the PMOS devices have a threshold voltage of -4.2 V at room temperature. The effective channel mobility is around 20 cm/sup 2//Vs for the NMOS devices and around 7.5 cm/sup 2//Vs for the PMOS devices. Several digital circuits, such as inverters, NAND's, NOR's, and 11-stage ring oscillators are fabricated using these devices and exhibited stable operation at temperatures ranging from room temperature to 300/spl deg/C. These digital circuits are the first CMOS circuits in 6H-SiC to operate with a 5-V power supply for temperatures ranging from room temperature up to 300/spl deg/C.