Electrical isolation of InGaP by proton and helium ion irradiation

Formation of electrical isolation in n- and p-type In0.49Ga0.51P epitaxial layers grown on semi-insulating GaAs substrates was investigated using proton or helium ion irradiation. Sheet resistance increases with the irradiation dose, reaching a saturation level of approximate to10(9) Omega/square. The results show that the threshold dose necessary for complete isolation linearly depends on the original carrier concentration either in p- or n-type doped InGaP layers. Thermal stability of the isolation during postirradiation annealing was found to increase with accumulation of the ion dose. The maximum temperature at which the isolation persists is congruent to500 degreesC. (C) 2002 American Institute of Physics.