Comparative Study of Gamma-Ray-Irradiation Effects on N-Type GaAs and InP

Radiation damage effects on electrical properties of n-type GaAs and InP bulk crystals have been investigated. Higher tolerance of InP to gamma-ray irradiation than GaAs was observed. The effects on GaAs strongly depend on the initial carrier concentration. Ihe critical value of concentration is taken to correspond to the border value of metal-nonmetal transition introduced by Mott. All InP samples with several different carrier concentrations showed almost completely unchanged properties after 1×109 R irradiation at 44°C. This extreme tolerance in InP to irradiation is believed to be caused by annihilation of unstable defects and also association of oppositely charged defects.