Micro-Raman spectroscopy has been used to study the dependence between the carrier concentration and electrical mobility in n-doped 3C-SiC films grown on (111) and (100) Si oriented substrates. Local stacking variations observed on the (111) 3C-SiC surface lead to a worse crystal morphology compared to (100) 3C-SiC films resulting in a decrease of the average bulk mobility.