The aim of this work is to develop the bulge test technique combined with the micro-Raman analysis and a refined load-deflection model for high quality 3C-SiC squared-membranes. By the minimization of the total elastic energy, starting from the isotropic relation between the stress tensor and the strain tensor, it is possible to calculate the relationship between the maximum deflection and the applied pressure, in both regime of small and large deflection. Furthermore, the relationship between the measured shift of Raman Transverse Optical (TO) phonon modes and the total residual strain (Δa/a) within the epitaxial 3C-SiC layer was found and in order to understand the stress distribution within the membrane, TO Raman shift maps were performed along the corner and the border of the membrane.