Off-state breakdown optimization in field plated GaAs-pHEMTs by means of two-dimensional numerical simulation

The optimization of a field plated pHEMT structure has been presented. It has been shown that by optimizing the FP length (LFP) and the SiN layer thickness the off-state breakdown voltage can be improved as much as four times for the selected pHEMT structure. Choosing the right SiN thickness (in this case in the 40-60nm range) and LFP (in this case in the 0.8-1.2um range) is crucial in order to obtain a significant benefit in the device off-state breakdown