Improved stability in wide-recess InP HEMTs by means of a fully passivated two-step-recess gate

Abstract

We report two-step-recess gate InP HEMTs with a new process option suitable for producing a wide recess. In the new devices the gate recess is completely covered with a passivation film. Though the gate recess is extremely wide, a transconductance of 1 S/mm and a cutoff frequency of 208 GHz are achieved with 100-nm gate devices. Moreover, a huge improvement in the drain reliability is achieved by the wide recess which reduces hot-carrier-induced degradation, and by the full passivation which eliminates the instability related to the recess surface. © IEICE 2006.