Lattice parameter changes and point defect reactions in low temperature electron irradiated AlAs

Abstract

X-ray diffraction was employed to investigate damage accumulation and the subsequent thermally activated annealing reactions in AlAs layers on GaAs substrates. Irradiations were performed at 4.6 K with 2.5 MeV electrons up to a total dose of 2×1019 electrons/cm2. The irradiation-induced increase of the lattice parameter amounts to about half of the changes observed in the GaAs substrates. There is a major annealing step near room temperature, a rather continuous annealing up to 500 K, and a final recovery stage between 700 and 900 K. The observations are discussed in relation to the resistance of AlAs against amorphization under ion irradiation.