InN films have been successfully grown on sapphire substrates by MOVPE using trimethylindium (TMIn) and 1,1-dimethylhydrazine (DMHy) with N-2 carrier. DMHy is an advantageous precursor of N as it decomposes efficiently at relatively low temperature (T-50=420 degrees C) compatible with the InN growth. The reactor is specially designed so as to avoid parasitic reaction between TMIn and DMHy occurring at room temperature. The growth feature was studied by varying growth temperature, V/III ratio, TMIn flow and reactor pressure. The InN films were obtained at 500-570 degrees C and 60-200 Torr with a V/III ratio optimized to 100-200. The In droplets are seen on the grown surfaces, indicating an excess supply of TMIn. It is demonstrated that the InN films grows on the sapphire substrate in a single domain with an epitaxial relationship, [1 0 (1) over bar0 1](InN)//[1 1 (2) over bar 0](sapphire). (C) 2009 Elsevier B.V. All rights reserved.