In this work we report on 3C-SiC heteroepitaxial growth on 4H-SiC(0001) substrates which were patterned to form mesa structures. Two different deposition techniques were used and compared: vapour-liquid-solid (VLS) mechanism and chemical vapour deposition (CVD). The results in terms of surface morphology evolution and the polytype formation using these growth techniques were studied and compared. It was observed both 4H lateral growth from the mesa sidewalls and 3C enlargement on top of the mesas, the former being faster with CVD and VLS. Only VLS technique allowed elimination of twin boundaries for proper orientation of the mesa sidewalls.