Suppression of Stiction in MEMS

Abstract

Stiction failures in microelectromechanical systems (MEMS) occur when suspended elastic members are unexpectedly pinned to their substrates. This type of device failure develops both in fabrication and during device operation, being a dominant source of yield loss in MEMS. Stiction failures require first a collapse force that brings the elastic member contact with the substrate followed by an intersolid adhesion sufficiently large to overcome the elastic restoring force. Stiction failure mechanisms have been studied extensively elsewhere [1]. This paper briefly summarizes these mechanisms in a the practical way. Over the last decade, stiction failure rates in MEMS have been minimized using a wide variety of processing, surface treatment, and physical schemes. An update of these methods is provided.

Plasma Based Dry Release of MEMS Devices

“…A third possible adhesion cause can occur if suspended membrane is placed in contact with the lower contact surface due to some external force. This adhesion can occur due to deliberate placement of collapsing forces or can be due to shock effect (Mastrangelo, 2000).…”

“…The figure shows that beam is adhering to the substrate at a distance d = (L-x) from its tip. We can calculate the total energy of the system which is sum of the elastic and surface energies and is given (Mastrangelo, 2000) by…”

Microworld Modeling in Vacuum and Gaseous Environments

“…Capillary adhesion is an important source of perturbation in miniaturized systems. MEMS breakdown is often caused by adhesion problems [47,[63][64][65]91]. Capillary condensation can be modeled thanks to the so-called Kelvin equation:…”

Electromechanical characterization of a new micro programmable blazed grating by laser Doppler vibrometry

“…This design results in an approximately pure rotation, improving the grating's diffraction efficiency. Meanwhile, the dimple structure can also help in avoiding both the process-caused stiction during the fabrication and in-use stiction during the operation (Mastrangelo 2000;Tas et al 1996).…”