Direct observation of the silicon nitride on amorphous silicon interface states

We report on the investigation of the silicon nitride/hydrogenated amorphous silicon interface by capacitance measurements. We observe that the ‘‘slow’’ interface states are located inside the silicon nitride layer, while the energy distribution of the ‘‘fast’’ interface states is peaked at 0.7 eV below the hydrogenated amorphous silicon conduction band with an integrated value of 2×1011 cm−2.