Dielectric characteristics of gamma irradiated Au/SnO2/n-Si/Au (MOS) capacitor

The dielectric characteristics of gamma irradiated Au/SnO2/n-Si/Au (MOS) capacitor were studied. The MOS capacitor was irradiated by a 60Co gamma radiation source with a dose rate of 0.69 kGy/h. The dielectric parameters such as dielectric constant (ε′), dielectric loss (ε″), loss factor (tan δ) and ac electrical conductivity (σac) were calculated from the capacitance-voltage (C-V) and conductance-voltage (G/ω-V) measurements. It is found that the C and G/ω values decrease with the increasing total dose due to the irradiation-induced defects at the interface. Also, the calculated values of ε′, ε″ and σac are found to decrease with an increased radiation dose. This result indicates that the dielectric characteristics of the MOS capacitor are sensitive to gamma-ray dose.