Effect of Substrate Temperature on Structure, Morphology and Optical Properties of β-Ga2O3 Thin Film Grown on GaN by MBE

Authors: Boyuan Feng, Gaohang He*, Zhengcheng Li, Ying Wu, Zhongming Zeng and Sunan Ding

DOI: 10.23880/nnoa-16000208

Volume 6, Issue 1

Abstract

The structure, morphology and optical properties of β-Ga2O3 thin films grown on GaN at various substrate temperature by ozone molecular beam epitaxy (MBE) are investigated in this work. (-201)-oriented β-Ga2O3 thin films are formed on c-plane GaN template substrate. When the substrate temperature increases, the crystal quality of β-Ga2O3 thin film improves, and a high-crystalline-quality β-Ga2O3 thin film is obtained at the substrate temperature of 700 °C. The Φ scans of X-ray diffraction is utilized to characterize the β-Ga2O3 thin film, from the result we find that the β-Ga2O3 thin film has a six-fold domain structure, attributed to the epitaxial relationships (β-Ga2O3 [010] // GaN [11-20] and β-Ga2O3 [102] // GaN [1-100]). Base on the morphology, it can be seen that the β-Ga2O3 thin film follows the island-growth model, and the size of the island increases as the substrate temperature increases. Furthermore, it is found that the defect related luminescence decreases with the increase of substrate temperature by analyzing the CL spectra, implying the improvement of crystal quality. The presented optimized β-Ga2O3 thin film grown on GaN template substrate should effectively promote the development of high reliable performance self-powered ultraviolet (UV) photodetector based on the Ga2O3/GaN heterojunction.

Keywords: β-Ga2O3; MBE; GaN Template Substrate; Temperature Influence

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