Electronic and transformation properties of a metastable defect introduced in epitaxially grown sulfur doped n-GaAs by particle irradiation

We report on the electronic and metastable properties of a new defect, EαIR10 positioned 0.262 eV below the conduction band, and introduced after particle irradiation of sulfur doped epitaxial n-GaAs. Using deep level transient spectroscopy (DLTS), we detected EαIR10 after 5.4 MeV He-ion, 10 and 12 MeV electron, and 1 MeV proton irradiations. However, we could not detect EαIR10 after irradiation by electrons with energy 0.2–2.4 MeV. DLTS measurements coupled with bias-on/bias-off cooling cycles were used to study the removal and introduction kinetics of EαIR10. After removing EαIR10 (ΔEremoval=0.76±0.08 eV) by zero bias annealing at room temperature, it can be re-introduced by reverse bias annealing (ΔEintroduction=0.58±0.08 eV), in the 230–260 K temperature region under predominantly first order kinetics. Annealing studies revealed that EαIR10 completely anneals out at 420 K.