InSb heteroepitaxial thin films were grown on GaAs (0 0 1) substrate by the temperature variation two-step growth process. X-ray rocking curve widths and electrical properties of the InSb films with different thickness were investigated. The best value of a 2-mum thick InSb film had an X-ray rocking curve width of 277 arcsec and room-temperature Hall mobilities, the carrier concentrations obtained were 55,000 cm(2)/V s and 1.5 x 10(16)/cm(3), respectively. The enhanced mobilities and reduced carrier concentration of InSb films suggested a low defect density due to confinement of the dislocation in the InSb/GaAs interface. (C) 2004 Elsevier B.V. All rights reserved.