60Co γ-ray irradiation effects on the capacitance and conductance characteristics of tin oxide films on Si

Metal-oxide-semiconductor (MOS) Schottky diodes were stressed with a bias of 0 V during 60Co-γ source irradiation with the total dose range from 0 to 500 kGy at room temperature. Tin oxide films on Si exhibited a typical behavior of a MOS structure. The variations in the interface state density and series resistance of the Schottky diode have been studied before and after irradiation. The capacitance–voltage (C–V) and conductance–voltage (G/ω–V) characteristics confirm that the interface state density (Dit) and series resistance (Rs) of the diode are important parameters that strongly influence the electrical parameters of MOS structures before and after irradiation. It has been found that Dit values of MOS structure decreases, while the Rs increases with increasing radiation dose. The single-frequency method of Hill–Coleman was used to determine the interface state density. The values, obtained before and after 60Co-γ source radiation for Dit, are the order of 1013 eV−1 cm−2.