【Epitaxy Papers】Tailoring annealing duration of gallium oxide film deposited by electron beam evaporation

      Researchers from the Universiti Sains Malaysia have published a dissertation titled "Tailoring annealing duration of gallium oxide film deposited by electron beam evaporation" in Ceramics International.

Abstract

      The effect of annealing duration on various properties, including morphological, topological, compositional, structural, optical, and optoelectronic characteristics, of β-Ga₂O₃ films was investigated. The films were deposited on silicon/sapphire substrates via electron beam evaporation, followed by post-annealing treatment at 900⁰ C for 10, 20, 30, and 60 min. A maximum surface roughness of 10.70 nm was observed for the 30-min annealed film, as revealed by atomic force microscopy. Field emission scanning electron microscopy revealed that the grain size changed from small and, dense grains to large and, uniform grains with increased annealing duration. X-ray diffraction indicated a change from amorphous to polycrystalline structures, with optimal structural parameters (minimum values for full width half maximum, strain, and dislocation density) at 30 min. The film's optoelectronic parameters, such as refractive index and packing density, demonstrated an increase with the annealing duration, achieving maximum values at 30 min. Conversely, parameters like porosity exhibited a decrease with increased annealing time, reaching a minimum at the 30-min duration. Other parameters, such as absorption coefficient, extinction coefficient, sheet resistance, and thermal emissivity, did not exhibit a clear trend with respect to the duration of annealing. Therefore, we recommend an optimal post-deposition annealing duration of 30 min based on the results from the characterizations.

DOI：

https://doi.org/10.1016/j.ceramint.2025.04.412