**4. Conclusions**

The mechanical properties of a 4H-SiC circular membrane were investigated through the determination of its Young's modulus and residual stress. Two methods were implemented and compared. The first one was based on bulge test, where the static behavior of the membrane submitted to a high external pressure was monitored. The second method was based on LDV measurements, where the dynamic mechanical response of the membrane was investigated. An inverse problem approach, based on finite element method, was implemented in order to combine the static and dynamic results, allowing the determination of the mechanical properties of the 4H-SiC circular membrane. The two methods provided very similar results since one obtained a Young's modulus of 410 GPa and a residual stress value of 41 MPa from bulge test against 400 GPa and 30 MPa for the LDV analysis. The calculated Young's modulus is in good agreemen<sup>t</sup> with literature values for SiC thin film. Moreover, the process allows the full removal of the highly doped 4H-SiC substrate and the local release of the epitaxial layer, thus realizing membranes with thickness uniformity determined by the epitaxial layer growth. Consequently, a new range of MEMS can be developed using 4H-SiC based-material.

**Author Contributions:** M.C. conceived the 4H-SiC circular membrane; J.B.M. performed the experiments; D.C. provided simulation tools; N.P., F.B. and L.C. designed the experiments; J.B.M., J.-F.M., M.C., and D.A. participated in the writing of the original draft; J.B.M. wrote the paper.

**Funding:** This research received no external funding.

**Acknowledgments:** J.B.M. wishes to thank "Region Centre Val de Loire" and "Conseil Géneral d'Indre et Loire" for the financial support of this work, in the framework of his PhD fellowship.

**Conflicts of Interest:** The authors declare no conflict of interest.
