Charge-collection characteristics of GaAs MESFETs fabricated with a low-temperature grown GaAs buffer layer: computer simulation

Two-dimensional device simulations of GaAs MESFETs fabricated with a low-temperature grown GaAs (LT GaAs) buffer layer reveal a sensitive dependence of the charge-collection characteristics on various structural and operational parameters. Simulations performed for above-band-gap pulsed laser excitation indicate that, even when the bulk of the charge is deposited above the LT region, the improved SEU and charge-collection performance of LT GaAs devices largely is a consequence of the reduced efficiency of the carrier-induced charge-enhancement (gain) mechanisms.