Recess dependent breakdown behavior of GaAs-HFETs

GaAs based HEMT devices were fabricated with a constant recess towards the source, whereas the recess width towards the drain was varied. While the off-state breakdown voltage has been improved by the use of a wide recess towards the drain, no dependence of the on-state breakdown on the recess configuration was observed. The constant breakdown voltage in the on-state is analysed by the feedback parameters obtained from an extraction of the small signal equivalent circuit. Although the extrinsic gate drain capacitance could be reduced by the use of a wider recess configuration, it is assumed that the intrinsic drift region is independent of the recess configuration.>