【Substrate Papers】Structure and properties of boron-implanted β-Ga₂O₃ monocrystals

      Researchers from the Lobachevsky University have published a dissertation titled "Structure and properties of boron-implanted β-Ga₂O₃ monocrystals" in Vacuum.

Abstract

      Gallium oxide (Ga₂O₃) is one of the leading wide-bandgap semiconductors with significant potential for various applications. The doping of Ga₂O₃ with gallium isovalent elements allows modify the most important properties of this semiconductor. However, only a limited number of studies have been conducted on the doping of Ga₂O₃ with boron, the impurity with the lowest atomic mass among isovalent elements and with the largest discrepancy in ionic radius. This work presents the results of a comprehensive study of the influence of boron implantation on the structure and properties of β-Ga₂O₃:Fe samples with surface orientation (-201). Some intriguing results were obtained. At a specific fluences, the γ-phase is formed (this phenomenon was previously found for β-Ga₂O₃ irradiated with some ions); however, the presence of the γ-phase was not revealed at higher B⁺ fluence. Following post-implantation annealing, the boron distribution profile exhibits a single-mode shape at low fluences and a two-mode shape at higher fluences. Irradiation at high boron fluences has been found to result in a reduction in the band gap for the as-implanted samples. First-principles calculations predict an increase in the band gap with elevation of boron concentration. Post-implantation annealing leads to the formation of a conductive layer. Thus, this study confirms the specific behavior of boron compared to other impurities isovalent with Ga.

DOI：

https://doi.org/10.1016/j.vacuum.2025.114129