Effect of neutron irradiation on the spectrum of deep-level defects in GaAs grown by liquid-phase epitaxy in hydrogen or argon ambient

We present results of experimental studies of capacitance--voltage characteristics, spectra of deep-level transient spectroscopy of graded high-voltage GaAs p+-p0-i-n0 diodes fabricated by liquid-phase epitaxy at a crystallization temperature of 900oC from one solution--melt due to autodoping with background impurities, in a hydrogen or argon ambient, before and after irradiation with neutrons are presented. After neutron irradiation, deep-level transient spectroscopy spectra revealed wide zones of defect clusters with acceptor-like negatively charged traps in the n0-layer, which arise as a result of electron emission from states located above the middle of the band gap. It was found that the differences in capacitance--voltage characteristics of the structures grown in hydrogen or argon ambient after irradiation are due to different doses of irradiation of GaAs p+-p0-i-n0 structures and different degrees of compensation of shallow donor impurities by deep traps in the layers. Keywords: GaAs, neutron irradiation, capacitance spectroscopy, p0-i-n0-junction, liquid-phase epitaxy, hydrogen, argon.