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

We report on the electronic and metastable properties of a new defect, E al pha IR10 positioned 0.262 eV below the conduction band, and introduced afte r particle irradiation of sulfur doped epitaxial n-GaAs. Using deep level t ransient spectroscopy (DLTS), we detected E alpha IR10 after 5.4 MeV He-ion , 10 and 12 MeV electron, and 1 MeV proton irradiations. However, we could not detect E alpha IR10 after irradiation by electrons with energy 0.2-2.4 MeV. DLTS measurements coupled with bias-on/bias-off cooling cycles were us ed to study the removal and introduction kinetics of E alpha IR10. After re moving E alpha IR10 (Delta E-removal = 0.76 +/- 0.08 eV) by zero bias annea ling at room temperature, it can be re-introduced by reverse bias annealing (Delta E-introduction = 0.58 +/- 0.08 eV), in the 230-260 K temperature re gion under predominantly first order kinetics. Annealing studies revealed t hat E alpha IR10 completely anneals out at 420 K. (C) 2000 Elsevier Science S.A. All rights reserved.