Integrated TiC coatings for moving MEMS

摘要

The application of wear-resistant coatings to microelectromechanical systems (MEMS) devices offers the potential of addressing the reliability of moving MEMS devices. However, coating non-line-of-sight, concealed surfaces in fully released 3D MEMS structures, especially those behind micron-sized apertures, is a difficult problem to overcome with most deposition techniques. A practical and viable solution to this problem is the direct integration of wear-resistant coatings into the MEMS fabrication process. Using this approach we have inserted pulsed-laser-deposited titanium carbide (TiC) coatings between critical polysilicon interfaces during fabrication of a MEMS device. This paper describes the details of inserting laser-ablated TiC coatings into a user-friendly surface micromachining process for MEMS to protect key sliding Si surfaces in MEMS motors. This hybrid technology is an effective way of inserting wear-resistant coatings such as TiC into the MEMS fabrication scheme.