Silicon carbide as a new micromechanics material

Silicon carbide (SiC) is studied as a material for micromechanics because of its high-temperature microelectronics capabilities and excellent mechanical properties. Fabrication of epitaxial 3C-SiC microstructures by bulk micromachining of the underlying silicon substrate and amorphous SiC microstructures by surface micromachining is investigated. Preliminary studies of the mechanical properties of epitaxial 3C-SiC films deposited on silicon are carried out to evaluate the potential of these films as a material for micromechanics. The residual stress and Young's modulus of 3C-SiC films are measured by load-deflection measurements of suspended diaphragms. The film's residual stress is tensile with an average of 275+or-45 MPa, while the in-plane Young's modulus averages 383+or-25 GPa. The bending moment due to the residual stress variation through the thickness of the film is determined by measuring the deflection curves of free-standing 3C-SiC cantilever beams. Amorphous SiC films sputtered from a SiC target are investigated for developing a SiC surface micromachining process.<
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