Characterization of insulated-gate versus schottky-gate InAs/AlSb HEMTs

Abstract

Fabrication and characterization of 225 nm gate-length InAs/AlSb HEMTs with excellent RF performance are reported. We show the importance of an insulating layer between the gate and the semiconductor to improve g_m, f_T and f_max, and most important from a noise perspective, the gate-leakage current I_G. By using an insulated-gate, I_G was reduced by two orders of magnitude. The insulated-gate HEMTs exhibited extrinsic f_T and f_max of 155 GHz and 115 GHz, respectively, at V_DS=0.5 V.