Lubrication of polycrystalline silicon MEMS via a thin silicon carbide coating

The contacting surfaces of a microfabricated polycrystalline silicon (polysilicon) double-clamped beam adhesion test structure have been modified with a thin ultra-hard, wear-resistant, and conformal silicon carbide (SiC) film. Adhesion forces in SiC-coated interfaces as a function of apparent area of contact have been determined quantitatively and compared with those in uncoated polysilicon contacts. Furthermore, contact reliability studies have been carried out by following the changes in physicochemical properties of the surfaces after >100 billion contact cycles. The results highlight the tribological benefits of SiC coating as a solid lubricant in devices undergoing cyclic contacts.

► Microfabricated test structure for adhesion force measurements and contact reliability studies.
► Suppression of stiction and wear in microelectromechanical systems (MEMS).
► Morphological, electrical, and chemical properties of polycrystalline silicon and silicon carbide surfaces undergoing cyclic contacts.
► Low surface energy materials.
► SiC film synthesis via low pressure chemical vapor deposition methods.