Indium gallium nitride (InXGa1 - XN) is focused as a photo-absorption material for solar cells because of the variable band gap in the range from 0.6 to 3.4 eV. Microcrystalline-InXGa1 - XN (mu c-InXGa1 - XN) films prepared by radio frequency (rf)-sputtering do not show good photosensitivity due to a formation of nitrogen vacancies in the films. In this paper, a post-nitriding at the surface of mu c-InXGa1 - XN films was examined by using a hot-wire chemical vapor deposition technique with various gases, N-2, NH3, H-2 and Ar. Atomic ratio of nitrogen at the surface of mu c-InXGa1 - XN films increased about 10% by an exposure of mixture gas of N-2 and NH3. (C) 2014 Elsevier B.V. All rights reserved.