Epitaxial growth of β-Ga2O3 thin films on Ga2O3 and Al2O3 substrates by using pulsed laser deposition

• Main Authors: Yuxin An, Liyan Dai, Ying Wu, Biao Wu, Yanfei Zhao, Tong Liu, Hui Hao, Zhengcheng Li, Gang Niu, Jinping Zhang, Zhiyong Quan, Sunan Ding
• Format: Article
• Language: English
• Published: World Scientific Publishing 2019-08-01
• Series: Journal of Advanced Dielectrics
• Subjects: Oxide semiconductor; β-Ga2O3 epitaxy; optical transmission spectrum; pulsed laser deposition; crystal growth
• Online Access: http://www.worldscientific.com/doi/pdf/10.1142/S2010135X19500322

In this work, we have successfully grown high quality epitaxial β-Ga2O3 thin films on β-Ga2O3 (100) and Al2O3(0001) substrates using pulsed laser deposition (PLD). By optimizing temperature and oxygen pressure, the best conditions were found to be 650–700∘C and 0.5Pa. To further improve the quality of hetero-epitaxial β-Ga2O3, the sapphire substrates were pretreated for atomic terraced surface by chemical cleaning and high temperature annealing. From the optical transmittance measurements, the films grown at 600–750∘C exhibit a clear absorption edge at deep ultraviolet region around 250–275nm wavelength. High resolution transmission electron microscope (HRTEM) images and X-ray diffraction (XRD) patterns demonstrate that β-Ga2O3(-201)//Al2O3(0001) epitaxial texture dominated the epitaxial oxide films on sapphire substrate, which opens up the possibilities of high power electric devices.