| Thin-film silicon carbide is a promising material for microelectromechanical systems (MEMS) because of its resistance to high temperatures and corrosive environments. However, more knowledge of its mechanical properties is needed to produce optimum MEMS devices with this material. Microsample tensile tests have been performed on this material to provide basic mechanical properties.; Tests were conducted using tensile specimens with a gage width of 600 μm, gage length of 4 mm, and different thicknesses. The specimens were tested with a custom-built microsample testing machine comprised of specially designed grips, a piezoelectric actuator, and a miniature load cell. Strain was measured with a direct strain measurement system, the Interferometric Strain Displacement Gage.; Obstacles to specimen fabrication resulted in a decrease in the amount and quality of the data. Material from Case Western Reserve University (CWRU) and Massachusetts Institute of Technology (MIT) was used; each material had unique fabrication challenges. The CWRU material had difficulties with adhesion of metal for strain measurement and excess material on some specimens. MIT fabrication was time consuming with low yield and required the collaboration of four institutions.; Results from tests on epitaxially grown material from CWRU show an elastic modulus of 428 ± 42 GPa, no Poisson's ratio results, and strengths of 1.13 ± 0.48 GPa and 1.65 ± 0.24 GPa for two different batches of material. The elastic modulus is lower than the calculated modulus of 456–466 GPa, but agrees well with previous bulge tests. Results from tests on polycrystalline material from MIT show an average elastic modulus of 428 GPa, strength of 0.49 ± 0.20 GPa, and an average Poisson's ratio of 0.24 for Batch One. Batch Two, a material with a different texture, resulted in an average elastic modulus of 448 GPa, strength of 0.81 ± 0.23 GPa, and an average Poisson's ratio of 0.17. |
