III-nitride films and their heterostructures are grown on vicinal sapphire and 4H-SiC (0001) substrates by plasma-assisted molecular beam epitaxy (rf-MBE). Surface morphologies, optical, structural and electrical properties of the films and heterostructures are systematically characterized. Dramatic improvements of the film quality are demonstrated. Furthermore, high electron mobility of the two-dimensional electron gas (2DEG) in the AlGaN/GaN heterostructure exceeding 1500 cm(2)/V s at room temperature in all-MBE-grown samples is obtained, which is extremely important for the electronic device applications. The performance of the results clearly shows the potential of the vicinal substrate usage for the III-nitride growth. (c) 2006 Elsevier B.V. All rights reserved.