Improved model for kink effect in AlGaAs/InGaAs heterojunction FET´s

The kink effect in an AlGaAs/InGaAs HJFET has been investigated with regard to optical wavelength, temperature and gate voltage. The study reveals that the drain current value measured at the drain voltage lower than the kink voltage increases by irradiating white light onto the device, indicating the irradiation-induced kink effect recovery. The degree of the kink disappearance exhibited a significant optical wavelength dependence. We also found that the kink effect is suppressed either by increasing the temperature or by applying a high gate voltage where parallel conduction takes place. Based on these experimental results, we propose an improved model for the kink effect in an AlGaAs/InGaAs HJFET in which the kink effect is closely related to carrier trapping at the hole traps in the AlGaAs donor layer