We present a method for growing low-doped 6H SiC films using chemical vapour deposition in a hot-wall system. The study discusses the influence of temperature, growth rate and C/Si ratio on the purity of the layers. Furthermore, we make a comparison between methane and propane as carbon source, and investigate the influence of bake-out prior to growth. The films are characterised using low temperature photoluminescence. The relative intensity of the free exciton related luminescence as compared to impurity related bound exciton recombination is discussed in terms of material purity. A capacitance-voltage technique is used to determine the doping concentration.