ABSTRACT
This chapter describes applications of the spectroscopic techniques for the study of micro-electromechanical systems (MEMS). The main focus is on Raman spectroscopy because this technique can be used to measure local mechanical stress. Residual stresses and stress gradients that are present in freestanding films in MEMS can have a detrimental effect on the performance of these systems. Stiction and friction are typically of concern for MEMS with moving and touching parts, such as microgears and switches. Polarized light with wavelengths ranging from ultraviolet to near-infrared is reflected from the sample surface, and the change in the polarization is measured. Curvature of functional parts of MEMS can be detrimental to the device performance. Several techniques exist to measure this curvature, such as optical interferometry, slope measurements, and dynamic focus. X-Ray Photoelectron Spectroscopy is mainly used to obtain information on the chemical bonds on surfaces and to determine the thickness of thin films.
