Epitaxial Growth and Solar-Blind Photoelectric Characteristic of Ga2O3 Film on Various Oriented Sapphire Substrates by Plasma-Enhanced Chemical Vapor Deposition

The epitaxial growth of Ga2O3 thin films is important for their applications in electronic and optoelectronic devices. Herein, the growth of Ga2O3 thin films on various oriented (c-, a-, m-, r-plane) sapphire substrates by plasma-enhanced chemical vapor deposition (PECVD) is investigated using high purity metallic Ga and oxygen (O-2) as precursor materials and argon (Ar) as carrier gas under a relatively lower growth temperature compared with other CVD methods. The effects of the substrates orientation to the surface morphology, crystal orientation, growth rate, optical properties, and solar-blind photoelectric properties of Ga2O3 thin films are studied. The epitaxial film grown on the c-plane sapphire substrate exhibits the best crystallinity and smooth surface, while that grown on the r-plane shows the fastest growth rate of 1.97 mu m h(-1). The photodetector based on the Ga2O3 film grown on the c-plane exhibits the lowest dark current of 0.17 nA, the highest I-light/I-dark ratio of 242.47, and the fastest response time of 0.31 s, while that of grown on the m-plane shows the highest responsivity (R-lambda) of 27.71 mA W-1.