Authors: D. Garmire, H. Choo, R.S. Muller, S. Govindjee and J. Demmel
Affilation: UC Berkeley, United States
Pages: 550 - 553
Keywords: electrometrology, process characterization
We have developed a CMOS-compatible, compact device and a simple procedure for measuring three important fabrication characteristics of planar-processed microelectromechanical (MEMS) structures: in-plane over- or under-cut, Young’s Modulus, and comb-drive forces in a MEMS process. MEMS engineers use these three properties extensively to evaluate processed part behaviors such as resonant frequencies, tolerances, and deformation. Accurately determining these few properties also enables the determination of many other important properties. This device is suitable for inexpensive process verification and system calibration applications. We have measured over-cut in an SOI process on a 50 micron thick device layer as 0.16±0.05 microns compared with an optical measurement of 0.1±0.1 microns, the comb-drive fringing field factor as 1.39±0.06, and the Young’s Modulus as 156±4GPa. We are currently manufacturing the device in silicon carbide and silicon germanium processes and intend to report cross-wafer variations.