Suppression of wear in cyclically loaded polycrystalline silicon MEMS via a thin silicon carbide coating

摘要

The surfaces of a microfabricated polysilicon test structure, designed to measure adhesion forces in MEMS, were modified with a thin (∼50 nm) silicon carbide coating to take advantage of the outstanding tribological, electrical, and chemical properties of polycrystalline SiC (polySiC). Adhesion forces in polySiC-coated interfaces as a function of apparent area of contact have been determined quantitatively and compared to those in uncoated polycrystalline silicon (polySi) contacts. A detailed study of changes in physico-chemical surface properties after >100 billion contact cycles is also presented, highlighting suppression of wear upon SiC coating.