Radiation and process-induced damage in Ga2O3

Ga₂O₃ is gaining attention for high breakdown electronics. The β-polymorph is air-stable, has a wide bandgap (~4.6 eV) and is available in both bulk and epitaxial form. Different types of power diodes and transistors fabricated on Ga₂O₃ have shown impressive performance. Etching processes for Ga₂O₃ are needed for patterning for mesa isolation, threshold adjustment in transistors, thinning of nano-belts and selective area contact formation. Electrical damage in the near-surface region was found through barrier height changes of Schottky diodes on the etched surface. The damage is created by energetic ion bombardment, but may also consist of changes to near-surface stoichiometry through loss of lattice elements or deposition of etch residues. Annealing at 450°C removes this damage. We also discuss recent results on damage introduction by proton and electron irradiation. In this case, the carrier removal rates are found to be similar to those reported for GaN under similar conditions of dose and energy of the radiation.