Energy and Temperature Dependence of Electron Irradiation Damage in GaAs

The energy and temperature dependences of electron damage in GaAs have been measured. The energy dependence data have been compared with theoretical calculations made using the RECOIL code. Both the carrier removal and the scattering addition can be fit by the theory using reasonable assumptions. The carrier removal rate (at higher energies) requires a displacement threshold of ~25 eV, and the scattering addition is fit best if an effective charge of 25% of the defects in the clusters is assumed. The carrier removal is dominated by isolated defect production, at least up to ~50 MeV, whereas multiply charge clusters are more effective scatterers. These clusters are more readily produced by higher-energy electrons. An isolated defect annealing stage exists at 200 to 250°K, but the clusters anneal at all temperatures between at least 77 and 300° K.