Generation of EL2 defects by a 6-MeV proton irradiation of semi-insulating GaAs

The defects introduced in a bulk semi-insulating (SI) GaAs by a 6-MeV proton irradiation at 300 K were investigated with the electron paramagnetic resonance (EPR) detected via the magnetic circular dichroism of the optical absorption. EL2 defects (EL2(0) and EL2(+)) are introduced by proton irradiation in contrast to electron irradiation, the total introduction rate being 100 +/- 50 cm(-1). The radiation-induced EL2 defects could not be completely bleached. They have properties similar to the EL2 defects in a low temperature grown molecular beam epitaxy material. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.