Dynamic current-voltage characteristics of III-N HFETs

A comparative study of the dynamic current-voltage (DI-V) characteristics of III-N heterojunction and double heterojunction field-effect transistors (HFETs and DHFETs) reveals that the current and RF power collapse in HFETs arise from modulation of device series resistances under large input signal. A model based on space-charge limited current through the depletion regions formed at the gate edges due to the charge trapping explains the DI-V behavior and other observations related to the RF current collapse in III-N HFETs.