Homoepitaxial silicon carbide (SiC) films were grown on 3.5 degrees off-oriented (0 0 0 1) 6H-SiC by metal-organic chemical vapor deposition (MOCVD) using bis-trimethylsilylmethane (BTMSM, C7H20Si2). A pronounced effect of the growth conditions such as source flow rate and growth temperature on the polytype formation and structural imperfection of the epilayer was observed. The growth behavior was explained by a step controlled epitaxy model. It was demonstrated by high-resolution X-ray diffractometry and transmission electron microscopy that high-quality 6H-SiC thin films were successfully grown at the optimized growth condition of substrate temperature 1440 degrees C with the carrier gas flow rate of 10 sccm.