TCAD-Based Optimization of Field Plate Length & Passivation Layer of AlGaN/GaN HEMT for Higher Cut-Off Frequency & Breakdown Voltage

Abstract

ATLAS TCAD-based comparative investigation (mainly breakdown voltage, cut-off frequency and leakage current) has been presented in this work for different length of gate field plate and source field plate. 127 V of breakdown voltage has been achieved at 0.25 µm gate length having 0.8 µm gate field plate length and 1 µm source field plate length. By amalgamating source field plate, maximum cut-off frequency of 38 GHz was achieved at 0.25 µm channel length. Passivation layer permittivity and barrier thickness has also been used to optimize the device performance. The improvement in breakdown voltage is less prominent than the deterioration in cut-off frequency with the enhancement in passivation layer permittivity. Leakage current of source field plate HEMT has also been studied for different passivation layer permittivity.