Effects of γ-ray irradiation on the C–V and G/ω–V characteristics of Al/SiO2/p-Si (MIS) structures

The effect of the 60Co (γ-ray) exposure on the electrical characteristics of Al/SiO2/p-Si (MIS) structures has been investigated using capacitance–voltage (C–V) and conductance–voltage (G/ω–V) measurements. The MIS structures were stressed with a bias of 0 V during 60Coγ-sources irradiation with the total dose range from 0 to 25 kGy. The C–V and G/ω–V characteristics were measured at 500 kHz and room temperature before and after 60Coγ-ray irradiation. The results indicated that γ-irradiation caused an increase in the barrier height ΦB, interface states Nss and depletion layer width WD obtained from reverse bias C–V measurements. The series resistance Rs profile for various radiation doses was obtained from forward and reverse bias C–V and G/ω–V measurements. Both C–V and G/ω–V characteristics indicate that the total dose radiation hardness of MIS structures may be limited by the decisive properties of the SiO2/Si interface to radiation-induced damage. After γ-irradiation, the decrease in capacitance of MIS structure results in the increase in the semiconductor depletion width.