Thermal Management of β -Ga₂O₃ Current Aperture Vertical Electron Transistors

Beta-gallium oxide ( $\beta $ -Ga2O3) has attracted considerable attention for power devices due to its superior properties and the availability of device-quality native substrates compared to gallium nitride (GaN) technologies. In particular, devices such as the current aperture vertical electron transistor (CAVET) have a higher breakdown voltage compared to lateral transistors made from $\beta $ -Ga2O3. However, because of the low thermal conductivity of $\beta $ -Ga2O3, thermal management strategies at the device level are required in order to achieve high power operation. Here, we present a thermal modeling study of CAVET power transistors and analyze the impact of thermal management strategies on their thermal performance. Among the various cooling strategies, double-side cooling has the largest impact on device cooling. Double-side cooling in combination with a heat spreader can suppress the device’s thermal resistance from 24.5 to 4.86 mm $\cdot ^{\circ }\text{C}$ /W, allowing for a high-power-density CAVET device. The modeling and analysis results presented in this work can be utilized as a guide for improvement of the vertical $\beta $ -Ga2O3 device performance for future power electronics applications.