Electronic and transformation properties of a metastable defect introduced inn-type GaAs by α-particle irradiation

We report the electronic and transformation characteristics of an α-particle irradiation-induced defect in n-type GaAs with metastable properties, Eα3, as determined by deep-level transient spectroscopy. The Eα3, with an energy level at ${\mathit{E}}_{\mathit{c}}$-0.37 eV, captures electrons by multiphonon emission. It can be removed by hole injection and reintroduced during a first-order transformation under zero-bias annealing (activation energy ΔE=0.40 eV), or during reverse-bias annealing (ΔE=0.53 eV). It is suggested that Eα3 is related to a Si-impurity complex in n-type GaAs. Owing to its concentration and position in the band gap, Eα3 can significantly contribute to particle irradiation-induced carrier removal—due to its metastable properties the extent of the carrier removal may depend on bias and injection conditions.