(Invited) Fabrication and Characterization of High Power Ga₂O₃ Based Diodes

A review will be given of the device processing needs for Ga2O3 power rectifiers. The main devices employed in power converters and wireless charging systems will be vertical rectifiers and MOSFETs. This talk will focus on the issues for rectifier fabrication and characterization. The rectifiers involve thick epitaxial layers on conducting substrates and require stable Schottky contacts, edge termination methods to reduce electric field crowding, dry etch patterning in the case of trench structures, and low resistance Ohmic contacts in which ion implantation or low bandgap interfacial oxides are used to minimize the specific contact resistance. In addition, stable insulators for field plates with acceptable band offsets relative to the Ga2O3 to ensure adequate electrical field redistribution, and enhancement rectifier breakdown voltage will be discussed. Success in these areas would lead to rectifiers with better on-state performance and a much improved range of functionality for power switching characterizations.