Investigation of Anti-Stiction Coating for MEMS Switch using Atomic Force Microscope

This article discusses anti-stiction coating for Microelectromechanical System (MEMS) switch using atomic force microscope (AFM). In the air, stiction occurs by the attractive force that arises from the capillary force generated from forming a liquid meniscus by water vapor across MEMS switch gap, and the switch does not function normally. We have measured adhesion force for Au and Pt surfaces between 10% and 85% relative humidity (RH), and compared it with that of SiO₂, Si, and self-assembled monolayer (SAM) surfaces. Our measurements indicate that approximately 20 nm thick sputtered Au and Pt coatings are useful to prevent stiction of MEMS switch.