In this paper we study the influence two different post-growth processes on hetero-epitaxial 3C-SiC on Si substrate for 6 and 8 inches wafers. We studied the influence of wafer cutting process and the substrate partially etching. We find an increase of wafer curvature after each cut processes and every etching processes and a correspondent variation of the Raman shift. These result, confirmed by FEM, can be explained in term of the wafer symmetry breaking and the related relaxation under modified constrains due to the cutting and etching. The FEM analysis of the deformation state reveals a modification of the residual stress tensor which changes from a pure biaxial form to a more complicated one.