【Epitaxy Papers】Macro-scale phase purity and epitaxiality of pulse-laser-deposited Ga₂O₃ on c-plane sapphire

      Researchers from the Indian Institute of Technology Bombay have published a dissertation titled "Macro-scale phase purity and epitaxiality of pulse-laser-deposited Ga₂O₃ on c-plane sapphire" in Thin Solid Films.

Abstract

      In this work, the phase-purity and epitaxial quality of Ga₂O₃ thin films, grown by pulsed laser deposition, on c-plane sapphire substrates, is systematically investigated, primarily by a combination of different high-resolution X-ray-diffraction-based analyses. We observe that while the oxide grows predominantly in the (-201) orientation of the monoclinic β-phase, it contains some volume fraction of the hexagonal α-phase, tentatively close to the film-substrate interface. This is in contrast to some earlier observations, where the monoclinic β-phase was found to stabilize atop exactly three monolayers of the α-phase. However, no other polymorphic phases could be identified in the oxide films, irrespective of the film thickness. Phase-purity and epitaxial quality of β-Ga₂O₃ thin films, on macroscopic length-scales probed by X-ray diffraction techniques, are critical attributes determining the applicability of this ultra-wide-band-gap semiconductor for development of high-performance optoelectronic and microelectronic devices.

DOI：

https://doi.org/10.1016/j.tsf.2025.140673