The C/Si ratio dependence of growth rate, surface morphology, micropipe closing ratio, doping concentration and deep-level concentration have been investigated in fast epitaxial growth of 4H-SiC (0 0 0 1) epilayers by chemical vapor deposition in a vertical hot-wall reactor. The doping, Z(1/2) and EH6/7 centers concentrations of thick epilayers decrease with increasing C/Si ratio of source gases. By adjusting the C/Si ratio at 0.7, specular surface morphology with a low doping concentration of 1 x 10(13) cm(-3) has been obtained at a growth rate of 33 mu m/h, and the concentrations Of Z1/2 and EH6/7 centers have been kept low, 8 x 10(12) and 4 x 10(12) cm(-3), respectively. (c) 2005 Elsevier B.V. All rights reserved.