Electrical Properties of Electron-Irradiated GaAs

The electrical properties of electron-irradiated GaAs have been studied. A defect with an energy level located at Ec - 0.15 eV has been identified. It is likely an intrinsic defect as it is produced in all n-type materials. It removes carriers at a rate of 1.6 to 2.2 cm-1 in l-MeV irradiations and 4.5 to 5.9 cm-1 in 30-MeV irradiations. It anneals between 200 and 300°C with an activation energy of 1.2 eV. Another defect with an energy level located at ~Ec - 0.02 eV is also observed in Si-doped material. It removes carriers at a rate of 1.1 cm-1 in l-MeV irradiations and ~7.5 cm-1 in 30-MeV irradiations. It anneals in the same 200 to 300°C stage as the first level. A defect with an energy level located at Ev + 0.17 eV is observed in Zn-doped material following 1-MeV and probably 30-MeV irradiations. It removes carriers at a rate of 2.7 cm-1 in 1-MeV irradiations and ~6 cm-1 in 30-MeV irradiations. It anneals in a stage between 150 and 200°C. A second defect level located at Ev + 0.06 eV is also observed following 30-MeV irradiations. It removes carriers at a rate of ~4.5 cm-1. For heavier irradiations, annealing above 300°C becomes important, and the carrier concentration and the mobility do not anneal together as they do below 300°C in lower-fluence irradiations.