Synthesis of monoclinic structure gallium oxide film on sapphire substrate by magnetron sputtering

Abstract:

Gallium oxide (Ga2O3) films were deposited on singlecrystalline sapphire (0001) substrate by radio frequency (RF) magnetron sputtering technique in the temperature range of 300—500 °C. The microstructure of the β-Ga2O3 films were investigated in detail using X-ray diffractometer (XRD) and scanning electron microscope (SEM). The results show that the film prepared at 500 °C exhibits the best crystallinity with a monoclinic structure (β-Ga2O3). Structure analysis reveals a clear out-of-plane orientation of β-Ga2O3 || Al2O3 (0001). The average transmittance of these films in the visible wavelength range exceeds 90%, and the optical band gap of the films varies from 4.68 eV to 4.94 eV which were measured by an ultraviolet-visible-near infrared (UV-vis-NIR) spectrophotometer. Therefore, it is hopeful that the β-Ga2O3 film can be used in the UV optoelectronic devices. #$TABThis work has been supported by the National Natural Science Foundation of China (Nos.61274113, 61404091, 61505144, 51502203 and 51502204), the Opening Fund of Key Laboratory of Silicon Device Technology in Chinese Academy of Sciences, and the Tianjin Natural Science Foundation (Nos.14JCZDJC31500 and 14JCQNJC00800).#$TABE-mail:[e-mail]