4H-SiC layers have been homoepitaxially grown on 4°off-axis (0001) and (000-1) under various conditions by horizontal hot-wall CVD. We have investigated surface morphology and background doping concentration of the epi-layers on 4°off-axis substrates. Surface morphology grown on the (0001) Si-face showed strong step bunching under C-rich conditions. On the other hand, smooth surface morphology on the (000-1) C-face could be grown in the wide C/Si ratio range at 1600 °C. Site-competition behavior is clearly observed under low-pressure growth conditions on 4°off-axis (000-1) C-face, leading to a lowest doping concentration of 4.4x1014 cm-3.