Characterization of MEMS materials: measurement of etching properties and mechanical strength

The importance of a materials database necessary for the design and fabrication of MEMS devices is discussed. The author is conducting two projects aimed at developing a MEMS database. The first project focuses on the anisotropic etching properties of single crystal silicon. The effects of crystallographic orientation on etching rate are completely evaluated for a wide range of chemical etching conditions. This makes it possible to predict the etch profiles of single crystal silicon microstructures by numerical simulation. The second project is on the measurement of the mechanical characteristics of thin films formed on a silicon wafer. A new method for the uniaxial tensile testing of thin films is proposed. The test is performed on a single crystal silicon chip where the thin film specimen and the loading mechanism have been integrated. The mechanical strength of thin films is evaluated under uniaxial loading conditions.