Systematic investigation of the growth kinetics of β -Ga2O3 epilayer by plasma enhanced chemical vapor deposition

Abstract

β-Ga2O3 has attracted much attention due to its ultrawide-bandgap (∼4.9 eV) with a high breakdown field (8 MV/cm) and good thermal/chemical stability. In order for β-Ga2O3 to be used in electronic and optoelectronic devices, epitaxial growth technology of thin films should be given priority. However, challenges are associated with the trade-off growth rate with crystallization and surface roughness in conventional epitaxy. Herein, plasma enhanced chemical vapor deposition was used to grow the β-Ga2O3 epilayer, and the growth kinetics process has been systematically investigated. A high growth rate of ∼0.58 μm/h and a single 2¯01 plane orientation with a full width at half maximum value of 0.86° were obtained when grown on the c-plane sapphire substrate at the growth temperature of 820 °C. Then, a proposed model for the mechanism of nucleation and growth of β-Ga2O3 epitaxial films is established to understand the precursor transport and gas phase reaction process. This work provides a cheap, green, and efficient epitaxial growth method, which is indispensable for device applications of β-Ga2O3.