Novel silicon carbide mosfet's for monolithic integrated circuits

Abstract

Silicon carbide is well suited for high frequency power devices due to its high saturated electron velocity, high thermal conductivity, and high-breakdown field strength. While much of the focus of silicon carbide device research has been to demonstrate high frequency MESFET transistors, we describe a silicon carbide MOSFET with superior drive, gain, and high temperature performance. In addition, these MOSFET's have been configured in demonstration circuits revealing the first silicon carbide monolithic integrated circuits. One inch diameter, 6H p-type silicon carbide wafers were used as the starting material. Appropriately doped nand n+ epitaxial layers were grown by the chemical vapor deposition pmcess. The devices were mesa isolated using reactive ion etching. The gate oxide was grown with a thermal oxidation. Contacts to the drain and source were made with nickel and sintered using RTA. Electron beam direct write lithography was used to define the gates to obtain precise alignment and dimensional control.