Epitaxial growth of β-Ga 2 O 3 thin films on Ga 2 O 3 and Al 2 O 3 substrates by using pulsed laser deposition

• Published in: Journal of advanced dielectrics Vol. 9; no. 4; p. 1950032
• Main Authors: An, Yuxin, Dai, Liyan, Wu, Ying, Wu, Biao, Zhao, Yanfei, Liu, Tong, Hao, Hui, Li, Zhengcheng, Niu, Gang, Zhang, Jinping, Quan, Zhiyong, Ding, Sunan
• Format: Journal Article
• Language: English
• Published: 01.08.2019
• ISSN: 2010-135X; 2010-1368
• DOI: 10.1142/S2010135X19500322

In this work, we have successfully grown high quality epitaxial [Formula: see text]-Ga 2 O 3 thin films on [Formula: see text]-Ga 2 O 3 (100) and Al 2 O 3 (0001) substrates using pulsed laser deposition (PLD). By optimizing temperature and oxygen pressure, the best conditions were found to be 650–700 ∘ C and 0.5[Formula: see text]Pa. To further improve the quality of hetero-epitaxial [Formula: see text]-Ga 2 O 3 , 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 250–275[Formula: see text]nm wavelength. High resolution transmission electron microscope (HRTEM) images and X-ray diffraction (XRD) patterns demonstrate that [Formula: see text]-Ga 2 O 3 (-201)//Al 2 O 3 (0001) epitaxial texture dominated the epitaxial oxide films on sapphire substrate, which opens up the possibilities of high power electric devices.