Dynamic Operational Stress Measurement of MEMS Using Time-Resolved Raman Spectroscopy

A dynamic-stress analysis method, based on time-resolved micro Raman spectroscopy, has been developed for reliability studies of microelectromechanical systems. This novel technique is illustrated by measuring temporally and spatially resolved stress maps of a piezoelectrically actuated silicon microcantilever when driven at its first- (6.094 kHz) and second-order (37.89 kHz) resonant frequencies. Stress amplitudes of up to 180 plusmn 10 MPa were measured at the maximum stress locations. The time-resolved Raman stress measurements are compared to the results of finite-element analysis and laser Doppler vibrometry.[2008-0003].