Uniformity of thickness and carrier concentration of homo-epitaxial films grown on 3-in diameter 4H-SiC substrates using a horizontal hot-wall reactor has been investigated. From the comparison between the experimental results and temperature and gas flow simulation, it is found that the thickness (growth rate) distribution is closely related to the gas velocity distribution, and the carrier concentration distribution has strong correlation with the temperature distribution not on the surface of the susceptor plate but in the gas phase. It is pointed out that the growth rate uniformity of 3-in diameter wafer is degraded by the gas flow disturbance near the susceptor's side walls, and the carrier concentration uniformity is strongly related to the gas phase reaction of nitrogen containing species, such as N-2 and/or others. (C) 2003 Elsevier B.V. All rights reserved.