Thermal versus radiation-assisted defect annealing in β-Ga₂O₃

Gallium oxide (Ga₂O₃) exhibits complex behavior under ion irradiation since ion-induced disorder affects not only the functional properties but can provoke polymorphic transformations in Ga₂O₃. A conventional way used to minimize the lattice disorder is by doing postirradiation anneals. An alternative approach is to prevent the disorder accumulation from the beginning, by doing implants at elevated temperatures, so that a significant fraction of the disorder dynamically anneals out in radiation-assisted processes. Here, we use these two approaches for the minimization of radiation disorder in monoclinic β-Ga₂O₃ implanted to a dose below the threshold required for the polymorphic transformations. The results obtained by a combination of channeling and x-ray diffraction techniques revealed that implants at 300 °C effectively suppress the defect formation in β-Ga₂O₃. On the other hand, in order to reach similar crystalline quality in the samples implanted at room temperature, postirradiation anneals in excess of 900 °C are necessary.