First Demonstration of a Gallium Oxide Power Converter

Ultra-wide bandgap (UWBG) semiconductor materials are predicted to greatly improve the performance of next-generation power electronics. β-Ga<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> is a promising UWBG material due to its large critical electric field strength, readily accessible n-type doping, and the availability of native substrates. However, no power converters using only β-Ga<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> devices have been demonstrated yet because the field has prioritized low periphery devices with large unnormalized on-resistances. In this paper, we present the first demonstration of a dc-dc converter using β-Ga<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> lateral field effect transistors with large periphery. We first fabricate and package the transistors then place them into the high and low side switch of a buck converter circuit. The devices are tested at 45 V input voltage, 2.7 W output power, and the converter achieves an efficiency of over 90% under various operating conditions.