The impact of light on current DLTS and gate-lag transients of AlGaAs-GaAs HFETs

Gate-lag transients and "hole-like" deep level transient spectroscopy signals from AlGaAs-GaAs heterostructure field-effect transistors are shown to be suppressed by illumination with photons with energy larger than the AlGaAs bandgap. The observed pulse-response dependence on light intensity is reproduced and explained by two-dimensional numerical device simulations based on hole-trap behavior of surface deep levels.