High quality SiO₂/diamond interface in O-terminated p-type diamond MOS capacitors

Metal oxide semiconductor (MOS) capacitors were fabricated based on oxygen-terminated p-type (100) oriented diamond and SiO2 grown by atomic layer deposition. A detailed electrical characterization consisting of I–V, C–V, and C–F was performed in order to analyze the electrical properties of the structure. The MOS capacitor presented no detectable leakage current in forward and very low leakage current in reverse sustaining at least 6 MV/cm without degradation. The C–V measurements showed depletion and deep depletion regimes in forward and accumulation regimes in reverse, with a low density of interface states of [Formula: see text] along the diamond bandgap. The latter results were further validated by conductance and capacitance vs frequency measurements.