Electron irradiation effects in <i>p</i>-type GaAs

Abstract

Deep level centers produced by 1-MeV electron irradiation at room temperature on p-type GaAs (liquid- and vapor-phase epitaxial layers) have been studied by means of Deep Level Transient Spectroscopy and Deep Level Optical Spectroscopy. Activation energies, thermal and optical photoionization cross sections, and introduction rates have been measured for the main defects. The trap H1 is shown to have an introduciton rate (0.25 cm−1) different from that of the E3 center created in n-type GaAs. As previously reported H1 is found to be highly relaxed from the Franck-Condon shift parameter given by optical spectroscopy. New hole traps created with an introduction rate greater than 2 cm−1 have been detected for the first time by low-temperature transient spectroscopy measurements.