Proton-Induced Transient Charge Collection in GaAs and InAlSb/InAs-Based FETs

The single-event transient (SET) response of two different n-channel III-V field-effect transistor technologies (GaAs MESFET, InAlSb/InAs HEMT) is measured for the first time for MeV proton irradiation. The characteristics and mechanisms of the proton-induced response of these two technologies are presented and discussed in terms of previous heavy-ion and pulsed-laser measurements. The measurements show that the maximum collected charge, event cross section, pulse amplitude, and full width at half-maximum (FWHM) all increase with increasing proton energy, and decrease as the devices are biased more strongly in depletion. The results are consistent with the presence of charge-enhancement processes that are a consequence of ionization-induced hole accumulation in the substrate/buffer regions of the devices. The InAlSb/InAs HEMT measurements reveal at least an order-of-magnitude lower sensitivity to proton-induced transient generation than the GaAs MESFET in terms of both collected charge and cross section.