Composition analysis of β-(InxGa1-x)2O3 thin films coherently grown on (010) β-Ga2O3 via mist CVD

This study investigates the compositional analysis and growth of beta-(InxGa1-x)(2)O-3 thin films on (010) beta-Ga2O3 substrates using mist chemical vapor deposition (CVD), including the effects of the growth temperature. We investigated the correlation between In composition and b-axis length in coherently grown films, vital for developing high-electron-mobility transistors and other devices based on beta-(InxGa1-x)(2)O-3. Analytical techniques, including X-ray diffraction (XRD), reciprocal space mapping, and atomic force microscopy, were employed to evaluate crystal structure, strain relaxation, and surface morphology. The study identified a linear relationship between In composition and b-axis length in coherently grown films, facilitating accurate composition determination from XRD peak positions. The films demonstrated high surface flatness with root-mean-square roughness below 0.6 nm, though minor relaxation and granular features emerged at higher In compositions (x = 0.083) at the growth temperature of 750 degrees C. XRD results revealed that lattice relaxation were observed at a growth temperature of 700 degrees C despite low In composition. In contrast, at 800 degrees C, the In composition was higher than at 750 degrees C, and coherent growth was achieved. The surface morphology was the flattest at 750 degrees C. These findings indicate that the growth temperature plays a crucial role in the mist CVD growth of beta-(InxGa1-x)(2)O-3 thin films. This study offers insights into the relationship between In composition and lattice parameters in coherently grown beta-(InxGa1-x)(2)O-3 films, as well as the effect of growth conditions, contributing to the advancement of ultra-wide bandgap semiconductor device development. [GRAPHICS] .