Silicon carbide is an emerging material for fabrication of micro- and nanosystems. Its high melting point, high hardness, wear resistance, and chemical resistance make it well suited for micro- and nanoscale sensors and actuators designed to operate in harsh environments. In addition, its high modulus to density ratio makes silicon carbide attractive for micro- and nanoscale resonators.

Deposition of polycrystalline silicon carbide thin films on 100 and 150mm diameter silicon wafers is performed at temperatures as low as 700°C in a low pressure chemical vapor deposition reactor from the precursors 1,3-disilabutane and dichlorosilane. By controlling wafer-boat geometry, highly uniform films can be deposited and the origin of non-uniform growth is elucidated.

Mechanical property tuning is achieved by controlling the precursor flow rates. Films with low residual stress and low strain gradient, optimal for released micro- and nanosystems, are achieved. Electrical resistivity is tuned by controlling the flow rate of a dopant precursor, ammonia, as well as by varying post-deposition annealing conditions. X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and secondary ion mass spectroscopy are used to characterize the films. By correlating the variation in mechanical properties with film microstructure and elemental composition, the mechanisms behind the material property tuning can be explained.

These SiC thin films are implemented as wear-resistant coatings and high-performance structural layers in applications ranging from microsystems sensors to optical filters.