The charge-collection processes of GaAs field-effect transistors are investigated as a function of the incident laser pulse energy via time-resolved charge-collection measurements and by two-dimensional computer simulation. The measurements and simulations reveal a feature that persists on a time scale of 100 ps, the amplitude of which varies strongly with the injected carrier density (pulse energy). The appearance of this feature is associated with a barrier lowering effect at the source/substrate junction, coupled with the drift-assisted transport of electrons through the substrate to the drain contact. This behavior is similar, but not identical to bipolar-gain models that have been suggested previously. We introduce the concept of ion-track segments and illustrate their utility in interrogating the complex mechanisms of charge collection and enhancement in GaAs FETs.
No takes yet. Share an insight, caveat, or question.
McMorrow et al. (1998) studied this question.