(Invited) Gallium Oxide Process Development and Integration for Future RF and Power Switching Applications

Abstract

Beta-phase Gallium Oxide (BGO) is emerging as a high-performance, low-cost electronic device technology for future switching applications. BGO possesses unprecedented critical electric field strength that dominates switch loss figures of merit along with shallow donor energy and large-area native substrates manufactured from the melt. Clear commercial applications exist in vertical Schottky barrier diodes (SBD) offering performance near or surpassing SiC at much lower cost. This commercial pull will mature various BGO transistor applications such as fast-switch power converters made small enough for chip-level process integration.This abstract reviews BGO transistor development progress made by the Air Force Research Laboratory (AFRL) and the community at-large. AFRL has shown record-high transistor critical field strength, low dynamic switch losses surpassing the limit of Si, and early RF small and large signal power performance. Most recently, AFRL has made progress on vertical transistor topologies, self-aligned gate lateral transistors and dielectric optimization. Recent advances for these topics will be discussed and have culminated with large gate periphery BGO power switches and an early demonstration of the first ultra-wide bandgap integrated circuit. The integrated circuit monolithically combines a high-κ capacitor, SBD and power transistor all fabricated on a BGO common substrate.