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.