Verification of 2-D MEMS model using optical profiling techniques

Abstract

This paper describes the application of scanning white light interferometry to profile single layer and multilayer, surface micromachined, micromechanical elements. The measured profile data is used to verify a 2-D finite difference model of device deflection under pressure and electrostatic forces. Devices modelled include pressure sensors, switches and process characterisation structures. The model is designed to include effects such as non-rigid structure supports and stress gradients through the structure. The optical profiling is used to quantify the significance and deflection shape resulting from these effects. The optical profiling has been compared with the AFM profiling and some comparisons are made between these methods.