The effect of high-energy light-ion bombardment on defect-energy levels related to the stable and metastable states of EL2 in undoped semi-insulating GaAs was studied. The samples were irradiated to different fluences using 50MeV Li ions. The energy of the irradiated ions was chosen so that the range of the ions was greater than the sample thickness. Thus, implantation of the bombarding ions and formation of extended defects at the end-of-range, could be avoided. The modification of the existing native point defects and the formation of new point defects under bombardment were studied by photocurrent and thermally stimulated current spectroscopic measurements under photo-excitation of both sub-bandgap and above-bandgap lights.

Modifications of EL2 Related Stable and Metastable Defects in Semi-Insulating GaAs by High Energy Light Ion Irradiation. D.Kabiraj, S.Ghosh: Semiconductor Science and Technology, 2005, 20[10], 1022-6