Design of AlGaN/GaN HEMTs employing mesa field plate for breakdown voltage enhancement

We proposed the AlGaN/GaN high electron mobility transistors (HEMTs) employing the mesa field plate and carried out the detailed numerical simulation of device operation using ISE-TCAD. The reduction of peak electric field is required to achieve the high breakdown voltage of AlGaN/GaN HEMTs. Proposed AlGaN/GaN HEMT with both gate and mesa field plates simultaneously reduced the electric field concentration at the gate and the drain edge by decreasing the potential gradient along the 2-DEG channel. As the peak electric field at the drain edge was decreased, the breakdown voltage was increased by 66% compared with the AlGaN/GaN HEMT with the gate field plate only. The breakdown voltage could be increased without sacrificing any other forward characteristics due to the SiO2 passivation layer.