Oscillation behavior of two microstructures of MEMS is analyzed in this paper. That is associated with dynamic response of a lateral-vibratory comb-structure in micro gyroscope, and resonance oscillation of a micro-plate with residual stress resulting from film deposition in bulk silicon fabrication. The comb-based micro-gyroscope was fabricated in polysilicon substrate and driven by oscillating voltage. Based on dynamic equations of the microsystem, the responses of the system output are analyzed with different inputs and quality factors. Due to the difference of thermal expansion coefficients of the substrate and the films, residual stresses are normally generated in the layer deposition processing of MEMS fabrication that will affect the performance of the micro-devices. The relation between the residual stress and the membrane's first-modal frequency is presented for a rectangular layered-plate fixed at edges. When the silicon-substrate micro-plate with a single film is actuated by oscillation, the resonance-frequency can be measured so that the in-plane residual stress can be solved. The FEM simulation is also made whose result shows good agreement by the error less than 7 percent.

Date Published: 29 May 2002
PDF: 4 pages
Proc. SPIE 4537, Third International Conference on Experimental Mechanics, (29 May 2002); doi: 10.1117/12.468760

Published in SPIE Proceedings Vol. 4537:
Third International Conference on Experimental Mechanics
Xiaoping Wu; Yuwen Qin; Jing Fang; Jingtang Ke, Editor(s)