Simulation Based Breakdown Voltage Analysis Of 3-Step Field Plate AlGaN/GaN HEMTs

Abstract

The behavior of 3-step field plate High Electron Mobility Transistor (HEMT) structure under the influence of parameter variation like gate to drain length, length of third step of field plate, permittivity of spacer and oxide region etc. has been examined in this work using extensive ATLAS TCAD device software. The device breakdown voltage increases with increase in gate to drain distance. However marginal degradation in breakdown voltage with other device parameter is observed. With the change in spacer permittivity, significant enhancement in drain current is achieved with marginal change in breakdown voltage. Results shows that asymmetric Field Plate AlGaN/GaN HEMT device (i.e., higher gate to drain length than source to gate) offer higher breakdown voltage. It was also observed that, source side field plate configuration results in higher breakdown voltage as compared to drain side field plate.