We have fabricated self-assembled InN dots on GaN using 4H-SiC(0001) vicinal substrates (4 degrees off toward [11-20]). The size and density of InN dots were well controlled by changing the deposition amount and the growth temperature of InN. Atomic force microscope (AFM) observation revealed that the critical thickness of InN for 2D-3D transition was between 0.8 and 1.0 nm. In addition, it was found that the InN dots were preferentially formed at the multistep edges on GaN. Therefore, the preparation of periodic multistep structures on GaN is considered to be an effective way to obtain highly ordered self-assembled InN dot arrays. (C) 2017 Elsevier B.V. All rights reserved.