Electrical isolation of n-type GaAs layers by proton bombardment : effects of the irration temperature

Abstract

The electrical isolation in n-type GaAs layers produced by proton irradiation at temperatures from 2100 to 300°C was investigated. The threshold dose for the isolation (Dth) was found almost identical for irradiation at temperatures from - 100 to 220 °C. At 300 °C, a dose of ~=1.3 times higher is required for the isolation threshold. In samples irradiated to a dose of Dth at - 100 °C or nominal room temperature, the isolation is maintained up to a temperature of ≈ 250 °C. In those samples irradiated at 300 °C it persists up to ≈ 350 °C. For doses of 3Dth or above, the stability of the isolation is limited to temperatures of 450–650 °C, irrespective of the irradiation temperature (Ti). For practical applications where doses in excess to 5Dth are usually employed, the irradiation temperature (from - 100 to 300 °C) has only a minor effect on the formation and thermal stability of the electrical isolation.