Influence of particle size distribution on dielectric, electrical, and microstructural properties of aerosol-deposited Ga₂O₃ film for advanced electronic device

Gallium oxide (Ga₂O₃) films have been the subject of recent scientific and technological research, owing to their outstanding characteristics. In this study, a rapid and efficient aerosol deposition (AD) process was utilized to produce Ga₂O₃ films. The effect of the particle size distribution (PSD) of the columnar or plate-like Ga₂O₃ starting powder on the dielectric, electrical, and microstructural properties of the films was also investigated. The dielectric constant and loss tangent of polycrystalline β-Ga₂O₃ films fabricated using AD with narrow PSD Ga₂O₃ powder were 10 and 6.7% at 10 kHz, respectively. In contrast, the films composed of a wide PSD powder exhibited a dielectric constant of 18 and a loss tangent of 3.6%. The leakage current densities of 1.77 × 10⁻⁵ and 6.63 × 10⁻⁷ A/cm² at 5 V of the films using narrow and wide PSD powder were observed, respectively. In addition, the breakdown electric fields of the Ga₂O₃ films with narrow and wide PSD powder were 1.15 and 1.06 MV/cm, respectively. Qualitative and quantitative analyses of the surface and inner microstructure were conducted to elucidate the differences in film characteristics according to the PSD. Consequently, a wider PSD enables the production of relatively denser and flatter high-quality films owing to enhanced hammering and crush effects. These results suggest potential applications of Ga₂O₃ films fabricated using AD in various fields, such as capacitors, power semiconductors, and sensor devices.