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 electrical instabilities in the SiO2/6H‐SiC system and the behavior of the inversion layer at different temperatures. The analysis of hysteresis and deformation of capacitance‐voltage curves shows the presence of interface states and oxide traps with a density of approximately 5–7×1010 eV−1 cm−2 in the midgap and a peak of 3×1012 eV−1 cm−2 at E=Ev+0.53 eV. Ionic contamination of the oxide layer has also been investigated, by thermally stimulated ionic current: A mobile charge concentration in the range of 1012 cm−2 was found. Finally, it is shown, by charge‐voltage measurements, that the minority‐carrier generation is assisted by deep levels during the formation of the inversion layer.