Theoretical Power Figure-of-Merit in β -Ga2O3 Lateral Power Transistors Determined Using Physics-Based TCAD Simulation

We calculated power figure-of-merit (PFoM) in $\beta $ -Ga2O3-based lateral metal-semiconductor field-effect transistors (MESFETs) by simulating the current-voltage (I–V) and breakdown characteristics. Simulation results were benchmarked with the characteristics measured on similar devices. For theoretical analysis, we used atomistic analysis of carrier mobility, self-consistent simulation of electrostatics and carrier transport, and a refined impact ionization model. Our analysis revealed the importance of considering off-state leakage mechanism, 2-D electrostatics, and current conduction pathways for majority and (generated) minority carriers for avalanche breakdown simulation in $\beta $ -Ga2O3 lateral MESFETs. This is a significant advancement over the electric field-based approach that is used in literature for breakdown studies. This study also highlights the importance of considering extrinsic breakdown pathways that often limit the observation of avalanche breakdown in these devices.