【Epitaxy Papers】Effects of off-axis angles of 4H-SiC substrates on properties of β-Ga₂O₃ films grown by low-pressure chemical vapor deposition

      Researchers from the Xi’an University of Technology have published a dissertation titled "Effects of off-axis angles of 4H-SiC substrates on properties of β-Ga₂O₃ films grown by low-pressure chemical vapor deposition" in Applied Surface Science.

Abstract

      In this work, β-Ga₂O₃ films with (−201) preferred orientation were heteroepitaxially grown on SiC substrates with off-axis angles of 0°, 4° and 8° by low-pressure chemical vapor deposition (LPCVD). It is found that the crystal quality, surface morphology, electrical properties of the β-Ga₂O₃ films of the film are significantly sensitive to the off-axis angle of SiC substrates. The crystal quality and surface morphology of the film were significantly improved when the 4° off-axis substrate was used, of which the FWHM (Full width at half maximum) was as low as 0.169° and the Ra (Roughness Average) of the smooth surface was 1.98 nm. Due to the improvement of crystal quality, the Hall mobility of the films deposited on 4° off-axis substrates was increased to 50.88 cm²/V·s. The photoluminescence peak intensity of the film increases first and then decreases with the increase of the off-axis angle of the substrate. However, the use of the off-axis substrate has no obvious effect on the oxygen vacancy ratio of the films. The results of this study demonstrate the significance for the preparation of high quality heteroepitaxial β-Ga₂O₃ films on SiC substrate for the promising applications in power electronic and optoelectronic devices.

DOI：

https://doi.org/10.1016/j.apsusc.2024.161377