ELECTRICAL CHARACTERIZATION OF INSTABILITIES IN 6H SILICON-CARBIDE METAL-OXIDE-SEMICONDUCTOR CAPACITORS

Capacitance, charge, and current measurements have been performed on p -type 6H-SiC metal-oxide-semiconductor capacitors in order to study el ectrical instabilities in the SiO2/6H-SiC system and the behavior of t he inversion layer at different temperatures. The analysis of hysteres is and deformation of capacitance-voltage curves shows the presence of interface states and oxide traps with a density of approximately 5-7 X 10(10) eV-1 cm-2 in the midgap and a peak of 3 X 10(12) eV-1 cm-2 at E = E(v) + 0.53 eV. Ionic contamination of the oxide layer has also b een investigated, by thermally stimulated ionic current: A mobile char ge concentration in the range of 10(12) cm-2 was found. Finally, it is shown, by charge-voltage measurements, that the minority-carrier gene ration is assisted by deep levels during the formation of the inversio n layer.