Effect of defect bands on the electrical characteristics of irradiated GaAs and Si

Proton bombarded p-Si and neutron irradiated n-GaAs have been studied by DL TS, current-voltage, and capacitance-voltage measurements in metal-semicond uctor junctions. The junctions were prepared by evaporation of Al onto sili con and of gold onto GaAs. Both junctions exhibited defect bands after bomb ardment. The bombardment has shifted the Fermi-level pinning position, incr eased the ideality factor in both junctions, and also affected the temperat ure dependence of the ideality factor and that of the capacitance. The resu lts show that the main effect of the radiation is the generation of lateral ly inhomogeneous defects near the semiconductor surface.