A Physics-Based Compact Electrothermal Model of β -Ga2O3 MOSFETs for Device-Circuit Co-Design

The electrothermal coupling effect on transistors is an intractableness of power circuits optimization, particularly for recent novel materials with high performance but low thermal conductivity, like beta-gallium oxide (<inline-formula> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-Ga2O3). Self-consistent calculations of electrothermal coupling effect in <inline-formula> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-Ga2O3 metal-oxide–semiconductor field-effect transistors (MOSFETs) are essential to assess the thermal behavior from device to circuit level. In this article, we proposed a physics-based compact electrothermal model of <inline-formula> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-Ga2O3 MOSFETs. Analytical solutions of current, terminal charge, and channel temperature are obtained based on surface potential, Ward-Dutton’s charge-partitioning scheme, and Fourier’s heat conduction law, respectively. Moreover, temperature-dependence mobility and device power dissipation are employed to couple electrical and thermal properties by embedding a two-order RC thermal subcircuit. The model is rigidly verified by comparing against experimental data and 3-D-FEM simulations under different process conditions. Especially, the calibrated model is used to evaluate the effect of technology parameters such as substrate material and thickness on boost converter performance, providing design space in design-technology co-optimization (DTCO) flow.