Electrical isolation of n-type GaAs layers by proton bombardment: Effects of the irradiation temperature

The electrical isolation in n-type GaAs layers produced by proton irradiati on at temperatures from - 100 to 300 degrees C was investigated. The thresh old dose for the isolation (D-th) was found almost identical for irradiatio n at temperatures from -100 to 220 degrees C. At 300 degrees C, a dose of c ongruent to 1.3 times higher is required for the isolation threshold. In sa mples irradiated to a dose of D-th at -100 degrees C or nominal room temper ature, the isolation is maintained up to a temperature of approximate to 25 0 degrees C. In those samples irradiated at 300 degrees C it persists up to approximate to 350 degrees C. For doses of 3D(th) or above, the stability of the isolation is limited to temperatures of 450-650 degrees C, irrespect ive of the irradiation temperature (T-i). For practical applications where doses in excess to 5D(th) are usually employed, the irradiation temperature (from - 100 to 300 degrees C) has only a minor effect on the formation and thermal stability of the electrical isolation. (C) 1998 American Institute of Physics. [S0021-8979(98)03921-8].