Frequency dependence of transconductance on deep traps in GaAs metal semiconductor field-effect transistors

A transconductance spectroscopy method is introduced through computer modeling which provides an easy way to the determination of energy levels of surface states and bulk traps in a GaAs metal semiconductor field-effect transistor. It is shown that in the transconductance spectrum each trap will result in a peak at a frequency which is equal to the characteristic frequency of the trap. It is suggested that peaks due to surface states can be distinguished from those due to bulk traps in the gated channel region by the dependence of the surface-state peak height on the gate-source reverse bias. It is found that previous experimental reports of transconductance dependence on temperature and surface leakage current can be explained by the model developed in this study.