High Thermal Conductive Ga₂O₃ MOSFET with Diamond Substrate and its Simulation Analysis

Gallium oxide (Ga₂O₃) material has an ultra-wide bandwidth of 4.9 eV and a breakdown field strength of up to 8 MV/cm, which holds great promise in the field of high-power and low-power devices. However, due to the extremely low thermal conductivity of β-Ga₂O₃, between 10 and 27 W/(m K) at room temperature, the self-heating effect of devices based on this material is significant. We have carried out a study of lateral β-Ga₂O₃ MOSFET device materials and dimensions to improve the self-heating effect, device simulation and digital fitting, simulation and analysis of silicon, silicon carbide, aluminum nitride, and diamond substrate compared to gallium oxide in the self-heating effect of the advantages of exploring the device gate length and the gate leakage spacing on the device heat dissipation and the optimization of parameters. Finally, this article proposed a high thermal conductivity diamond substrate device structure, using gate length l_g = 8 μm, gate drain spacing l_gd = 13 μm, and gate source spacing l_gs = 7/9 μm. The peak temperature of the device is reduced by 65% compared to the gallium oxide substrate, providing a theoretical basis for the optimization of thermal design of gallium oxide devices in the future.