Alternative Magnesium Calcium Oxide Gate Dielectric for Silicon Carbide MOS Application

Abstract

AbstractFilms of MgO and MgCaO ternaries were grown at low temperature as dielectrics on 6H-SiC by gas-source MBE. MgO grown at 300 and 400°C revealed crystallites textured toward the (111) orientation on SiC (0001). A solid-solution Mg.75Ca.25O ternary was grown having a minimal lattice mismatch and low root mean square (RMS) roughness of 0.5 nm. SiC pretreatments in UV-ozone reduced carbon contaminants on the surface of SiC, but resulted in the increase of fixed oxide charge in the oxide/SiC interface. Electrical breakdown fields >3.5 MV cm-1 and low density of interface states on the order of 1011 cm-2eV-1 were achieved for a Mg.75Ca.25O ternary grown at 300°C. These oxides are presented for the first time as low temperature alternatives to SiO2 gate dielectrics for SiC MOS applications.