Field plated, gate work function engineered AlGaN channel HEMTs with improved DC, RF and power performance

Abstract

This paper presents the study of the impact of gate work function engineering on the performance of AlGaN channel high electron mobility transistor. The proposed devices with dual material and triple material gate structures result in improved electrical characteristics. The devices exhibit a peak transconductance of 11.86 mS, 11.80 mS respectively for triple and dual material gate structures. A comparative analysis on the performance of the proposed device structures with that of a conventional AlGaN channel HEMT is presented. The devices are able to offer superior RF performance compared to the conventional device with fT values of 0.89 GHz, 0.889 GHz for triple material and dual material gate devices respectively. By incorporating gate field plates, field crowding at the gate edge can be reduced further. The field plated structure can cater to better high voltage operation with a slight penalty on the high frequency performance.