Analysis of interface states and series resistance at MIS structure irradiated under 60Co γ-rays

In this research, we investigated the effect of 60Co γ-ray exposure on the electrical properties of Au/SnO2/n-Si (MIS) structures using current-voltage (I-V) measurements. The fabricated devices were exposed to γ-ray doses ranging from 0 to 300 kGy at a dose rate of 2.12 kGy h−1 in water at room temperature. The density of interface states Nss as a function of Ec-Ess is deduced from the forward bias I-V data for each dose by taking into account the bias dependence effective barrier height and series resistance of device at room temperature. Experimental results show that the γ-irradiation gives rise to an increase in the zero bias barrier height ΦBO, as the ideality factor n and Nss decrease with increasing radiation dose. In addition, the values of series resistance were determined using Cheung's method. The Rs increases with increasing radiation dose. The results show that the main effect of the radiation is the generation of interface states with energy level within the forbidden band gap at the insulator/semiconductor interface.