Electrothermal Simulation and Thermal Performance Study of GaN Vertical and Lateral Power Transistors

In this paper, we present self-consistent electrothermal simulations of single-finger and multifinger GaN vertical metal-oxide-semiconductor field-effect transistors (MOSFETs) and lateral AlGaN/GaN high-electron-mobility transistors (HEMTs) and compare their thermal performance. The models are first validated by comparison with experimental dc characteristics, and then used to study the maximum achievable power density of the device without the peak temperature exceeding a safe operation limit of 150°C (P₁₅₀°C). It is found that the vertical MOSFETs have the potential to achieve a higher P₁₅₀°C than the lateral HEMTs, especially for higher breakdown voltages and higher scaling level designs.