Articles techniques et présentations

Gallium Oxide (β-Ga2O3) is an emerging wide bandgap oxide semiconductor that has garnered attention for power electronic applications because of its large 4.8 eV bandgap energy and critical electric field strength of ~ 8 MV/cm [1]. However, due to Gallium Oxides' poor thermal conductivity k = 27 W/mK, the self-heating effects can severely limit device performance and reliability. This work aims to study the electrical and thermal response of a 2D lateral Gallium Oxide MOSFET using different gate dielectric oxide materials to investigate the dielectric effect of dissipating heat in the gallium oxide layer. The three gate dielectrics selected were Silicon Oxide (SiO2), Aluminum Oxide (Al2O3), and Hafnium Oxide (HfO2), as these are the three most commonly used gate oxides in conjunction with Gallium Oxide for power electronic applications. The simulations were carried out by employing the Semiconductor and Heat Transfer in Solids modules in COMSOL Multiphysics to simulate the phonon generation in the gallium oxide layer of the MOSFET structure. A convective heat flux domain was defined for the source, drain, and gate components of the MOSFET, and defining the semiconductor layer as the heat source. In addition, the gate was held at a constant 5 V bias while the drain was swept from -1 V to 12 V with a 0.1 V step. The results show that aluminum oxide helps dissipate heat more effectively than silicon oxide and hafnium oxide as a gate dielectric. A peak temperature of 718.2 K was observed for aluminum oxide as the gate dielectric, while silicon oxide had a peak temperature of 996.6 K and 1025.4 K for hafnium oxide. Aluminum oxide shows a 27.94% and 29.96% reduction in temperature compared to silicon oxide and hafnium oxide, respectively. This work considers three gate dielectrics and their effect on the thermal and electrical response of a 2D lateral gallium oxide MOSFET. The results showed that aluminum oxide helps dissipate heat more effectively than silicon oxide and hafnium oxide. This work adds further insights to the ongoing research on mitigating the self-heating effects of gallium oxide due to its poor thermal conductivity.