Enhanced thermal stability of Ga2O3 MOSFETs with nanocrystalline diamond field plate

The effect of the nanocrystalline diamond (NCD) field plate on the electrical and thermal characteristics of Ga2O3 MOSFETs is systematically investigated by electrothermal device simulation. The NCD field plate increases the drain current due to the suppression of the self-heating-effect-induced current drop in the saturation region for Ga2O3 MOSFETs. A >67 % reduction of maximum temperature rise can be achieved for the devices operating at P = 1.4 W/mm by using the NCD field plate. The peak temperature of the NCD field-plated Ga2O3 MOSFET decreases as the field plate length increases, while a thicker field plate support layer (>400 nm) almost elimi-nates the field plate effect. These results show that the NCD field plate can enhance the electrical and thermal characteristics of Ga2O3 MOSFETs, and provide insight into the thermal design of Ga2O3-based power devices.