Surface processes in MEMS technology

This review focuses on the problem of adhesion in microelectromechanical systems and on the application of the principles and techniques of surface science to understand and manipulate, at the atomic level, the interfacial forces which are responsible for strong adhesion in microdevices. Various approaches developed for reducing both release and in-use adhesion are discussed. They include surface roughening and chemical passivation. Results of ultrahigh vacuum studies on well-characterized surfaces are compared to experiments on test structures, such as cantilever beam arrays, which are specifically designed to study the surface properties of real micromechanical devices under normal operating conditions.