Growth and characterization of In0.17Al0.83N thin films on lattice-matched GaN by molecular beam epitaxy

Abstract

InxAl1−xN thin films were grown on c-plane GaN templates by plasma-assisted molecular beam epitaxy. The effect of the growth temperature on the quality and surface morphology of these InxAl1−xN thin films were examined. The alloy composition, crystalline quality and surface morphology were characterized by high-resolution x-ray diffraction, scanning electron microscopy, and atomic force microscopy. A very narrow growth temperature for high-quality In0.17Al0.83N was identified between 520 and 530°C. At the optimized growth temperature around 525°C, the In0.17Al0.83N thin films on lattice-matched GaN templates were grown with excellent crystalline quality. The value of full width at half maximum of the In0.17Al0.83N (0002) peak is 249.6arcsec, which is among the best results reported to date. The root mean square surface roughness of the In0.17Al0.83N thin films is as low as 0.47nm.