(658c) Growth and Characterization of Sic Films Deposited in a Large-Scale Lpcvd Reactor

Silicon carbide has properties such as high melting point, large bandgap, chemical resistance, high fracture toughness, and high elastic modulus which make it an attractive material for harsh environment micro- and nanoelectromechanical systems (MEMS and NEMS) applications. Silicon carbide is also sought after as a MEMS anti-stiction and wear-reducing coating. A method to deposit SiC thin films on silicon wafers with a single source precursor, 1,3-dislabutane, in a low pressure chemical vapor deposition (LPCVD) reactor has been developed. This method has been scaled-up to realize deposition on 4- and 6-inch wafers, which are compatible with micro- and nanomachining facilities. Amorphous SiC is attained at temperatures of 750°C and below, while polycrystalline films are attained at temperatures of 800°C and above. Uniform films with low surface roughness have been achieved using a closed boat configuration. Initially, films deposited had highly tensile residual stresses (>1.3 GPa), limiting the application of these films to chemically resistant and wear resistant coatings. Modifications to the reactor have reduced the residual film stress to below 0.3 GPa, allowing these SiC films to be used as structural layers in MEMS and NEMS devices.