60Co γ irradiation effects on the current–voltage (I–V) characteristics of Al/SiO2/p-Si (MIS) Schottky diodes

It is well known that the exposure of any semiconductor surfaces to the 60Co γ-ray irradiation causes electrically active defects. To investigate the effect of γ-ray irradiation dose on the electrical characteristics of metal–insulator–semiconductor (MIS) Schottky diodes, the fabricated devices were exposed to γ radiation at a dose of 2.12 kGy/h. The total dose range was from 0 to 450 kGy at room temperature. The density of interface states Nss as a function of Ess−Ev, the values of series resistance Rs and the bias dependence of the effective barrier height Φe for each dose were obtained from the forward bias I–V characteristics. Experimental results show that the γ-irradiation gives rise to an increase in the zero bias barrier height ΦBO, as the ideality factor n, Rs and Nss decreases with increasing radiation dose.