We compare two series of 4H-SiC layers grown with either silane/propane or hexamethyldisilane/propane precursor systems. In both cases, the growth rate increases with precursor flow. However it saturates and, then, tend to decrease at high temperature. The range of growth conditions (C/Si ratio, growth rate, growth temperature) which give good surface morphology has been studied. The operating windows are identical for the two systems In both cases, micro-Raman and LTPL spectroscopy confirm the formation of high quality 4H-SiC polytype.