Determination of Residual Stress in MEMS Cantilevers

The micro-electro-mechanical-system (MEMS) cantilevers fabricated using conventional MEMS fabrication techniques never appear to show the design modes of vibration. This could possibly result due to the residual stress in the fabricated structures arising due to processes like reactive ion etching (RIE) which is at the heart of most microfabrication techniques. We use micro-Raman spectroscopy (mu-RS) to study the residual stress profile in a siliconon-insulator (SOI) MEMS cantilever. The experimentally observed residual stress profile can be used as suitable inputs in finite element modelling (FEM) packages for designing MEMS structures which will work at stringent end-use specifications.