Correlation between deep level traps and reverse recovery of GaAs p–i–n diodes before and after neutron irradiation

Abstract

Using the deep-level transient spectroscopy and reverse recovery method, the minority carrier lifetime in the base n0-layers of high-voltage GaAs p+–p0–i–n0–n+-diodes grown by the liquid phase epitaxy in argon atmosphere has been estimated before and after irradiation by neutrons with the energy of 1 MeV and the fluence of 1.6 × 1014 cm–2. Correlation between the values of the minority carrier lifetime determined by both methods was found. EL2 defects where shown to govern the dynamic switching characteristics of non-irradiated GaAs diodes, while the switching process in the irradiated diodes is determined by the acceptor-like states of defect bands located above the midgap, which are D– states of a three-charged donor. Having been irradiated with neutrons, the diodes revealed a significant decrease in the time of their reverse recovery upon changing the character of the diode switching from the "hard" mode to the "soft" one.