Packaged β-Ga2O3 Schottky Diodes with Reduced Thermal Resistance by Substrate Thinning to 200μm

Abstract:
The wide-bandgap semiconductor gallium oxide (β-Ga2O3) is a promising candidate for power electronics due to its large bandgap, high critical electric field, and availability of large-size β-Ga2O3 bulk substrates that can be fabricated via standard melt-growth techniques. However, the low thermal conductivity of about 10–30 W/(m K) aggravates the thermal management of Ga2O3 power devices. In this contribution, large-area Ga2O3 Schottky barrier diodes based on a native substrate that was ground down to a thickness of 200 µm were assembled in TO-247 packages by soldering and gold wire bonding. The devices are capable of carrying a DC current of several amperes, and thermal measurements and simulations show that by substrate thinning the thermal resistance can successfully be reduced by more than half compared to standard cathode-side cooled Ga2O3 power diodes.