Compact Ga<sub>2</sub>O<sub>3</sub> Thin Films Deposited by Plasma Enhanced Atomic Layer Deposition at Low Temperature
Yue Yang,
Xiao-Ying Zhang,
Chen Wang,
Fang-Bin Ren,
Run-Feng Zhu,
Chia-Hsun Hsu,
Wan-Yu Wu,
Dong-Sing Wuu,
Peng Gao,
Yu-Jiao Ruan,
Shui-Yang Lien,
Wen-Zhang Zhu
Affiliations
Yue Yang
School of Opto-Electronic and Communication Engineering, Xiamen University of Technology, Xiamen 361024, China
Xiao-Ying Zhang
School of Opto-Electronic and Communication Engineering, Xiamen University of Technology, Xiamen 361024, China
Chen Wang
School of Opto-Electronic and Communication Engineering, Xiamen University of Technology, Xiamen 361024, China
Fang-Bin Ren
School of Opto-Electronic and Communication Engineering, Xiamen University of Technology, Xiamen 361024, China
Run-Feng Zhu
School of Opto-Electronic and Communication Engineering, Xiamen University of Technology, Xiamen 361024, China
Chia-Hsun Hsu
School of Opto-Electronic and Communication Engineering, Xiamen University of Technology, Xiamen 361024, China
Wan-Yu Wu
Department of Materials Science and Engineering, Da-Yeh University, Dacun, Changhua 51591, Taiwan
Dong-Sing Wuu
Department of Applied Materials and Optoelectronic Engineering, National Chi Nan University, Nantou 54561, Taiwan
Peng Gao
Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
Yu-Jiao Ruan
National Measurement and Testing Center for Flat Panel Display Industry, Xiamen Institute of Measurement and Testing, Xiamen 361004, China
Shui-Yang Lien
School of Opto-Electronic and Communication Engineering, Xiamen University of Technology, Xiamen 361024, China
Wen-Zhang Zhu
School of Opto-Electronic and Communication Engineering, Xiamen University of Technology, Xiamen 361024, China
Amorphous Gallium oxide (Ga2O3) thin films were grown by plasma-enhanced atomic layer deposition using O2 plasma as reactant and trimethylgallium as a gallium source. The growth rate of the Ga2O3 films was about 0.6 Å/cycle and was acquired at a temperature ranging from 80 to 250 °C. The investigation of transmittance and the adsorption edge of Ga2O3 films prepared on sapphire substrates showed that the band gap energy gradually decreases from 5.04 to 4.76 eV with the increasing temperature. X-ray photoelectron spectroscopy (XPS) analysis indicated that all the Ga2O3 thin films showed a good stoichiometric ratio, and the atomic ratio of Ga/O was close to 0.7. According to XPS analysis, the proportion of Ga3+ and lattice oxygen increases with the increase in temperature resulting in denser films. By analyzing the film density from X-ray reflectivity and by a refractive index curve, it was found that the higher temperature, the denser the film. Atomic force microscopic analysis showed that the surface roughness values increased from 0.091 to 0.187 nm with the increasing substrate temperature. X-ray diffraction and transmission electron microscopy investigation showed that Ga2O3 films grown at temperatures from 80 to 200 °C were amorphous, and the Ga2O3 film grown at 250 °C was slightly crystalline with some nanocrystalline structures.
