Characterization of stiction effects of an electrostatic micro positioner for probe storage

Abstract

We start by presenting a short explanation of the micro actuator working principle. The main contribution of this paper is the characterization of the coefficient of stiction between two silicon nitride parts of a MEMS actuator. Having one flat contact surface while the other is composed of many relatively sharp circular bumps, has the advantage that the effective contact area is drastically reduced. The stiction coefficient varies between 0-0.53 for the device configuration presented. The exact value depends closely on the electrostatically applied force which presses the textured part on to the smooth one. Individual measurements used are highly accurate (typically within 5 nm noise band) and identical measurements for the characterization of stiction show only a small variation, typically under 25nm on a range of 11.8µm.