Simulation Research on a Ga₂O₃-Based Superjunction Field Effect Transistor

The new superjunction (SJ) structure based on the charge compensation principle has greatly improved the limitation of low breakdown voltage (BV) and high specific on-resistance (R on,sp ) of conventional power devices. In this article, a depletion-mode β -Ga 2 O 3 metal-oxide-semiconductor field effect transistor (MOSFET) with a lateral SJ structure is designed and analyzed using Silvaco Atlas TCAD simulation software. This structure not only incorporates P-type NiO to achieve charge compensation in the SJ but also introduces a new electrode to enhance the device’s conduction characteristics and mitigate the concentration effect of the gate field under high voltage. Compared to conventional depletion-mode β -Ga 2 O 3 MOSFETs, the proposed device demonstrates substantial performance improvements, including a 93.8% increase in BV, a 57.6% reduction in R on,sp , and further optimizations in device parameters, resulting in a significantly higher power figure of merit (PFOM = BV 2 /R on,sp ). Finally, this structure can achieve a low R on,sp of 3.46 mΩ·cm 2 , with a BV of 1550 V and a PFOM of up to 694.364 MW cm −2 , which provides a new way to realize SJ devices on Ga 2 O 3 materials and has good application prospects.