Mode I and Mixed Mode I and II Measurements for Stiction Failed MEMS Devices

Abstract

Recently, we have shown that in-service repair of stiction failed MEMS devices is possible with structural vibrations. In order to further understand this phenomenon and better predict, theoretically, the onset of repair we have constructed an apparatus to determine the Mode I, II, and III interfacial adhesion energies of MEMS devices failed on a substrate. Though our method is general, we are specifically focused on devices created using the SUMMiT V process. An apparatus has been constructed that has 8 degrees-of-freedom between the MEMS device, the surface on which the device is failed, and a scanning interferometric microscope. Deflection profiles of stiction failed MEMS (micro-cantilevered beams 1500 microns long, 30 microns wide, and 2.6 microns thick) have their deflection profiles measured with nanometer resolution by the scanning interferometric microscope. Then non-linear elastic models are used in order to determine the interfacial adhesion energy between the failed micro-cantilevers and the surface. In this work we report the interfacial energies from Mode I and Mixed Mode I and II type failures. We also show further experimental results of repair of stiction failed MEMS and corresponding modeling results that use data from the Mode I and II experiments.