Dose dependence and annealing behaviour of radiation-induced defects in [formula omitted] implanted GaAs

Abstract

Single-crystal semi-insulating GaAs substrates implanted with 70 MeV 56 Fe ions with fluences varying from 5×10 12 to 1×10 14 ions/ cm 2 , have been investigated by optical transmission over photon energy range 0.1– 1.4 eV . The density of radiation-induced defect states shows a considerable increase for the fluences above 5×10 13 ions/ cm 2 . Annealing studies of the sample having the fluence of 1×10 14 ions/ cm 2 show that significant damage recovery occurs over the temperature range 100–500°C with activation energy of annealing to be 0.19 eV . The mid gap defect states are annealed out more rapidly than the near band edge defect states during annealing up to 350°C whereas the near band edge defect states are annealed out more rapidly than mid gap defect states during annealing between 350°C and 600°C.