Intelligent Automatic Meshing Of Multilayer CMOS Micromachined Structures For Finite Element Analysis

In this paper, we describe an automatic technique for meshing multilayer CMOS micromachined structures for Finite Element Analysis (FEA) from device layout. The technique is based on a 3D canonical representation of the different CMOS layers and feature recognition of plate masses, springs, beams and comb drives within the surface micromachined MEMS device. Manual meshing of devices for FEA is very tedious for multilayer structures as each layer must be separately meshed and subsequently merged. FE modeling experts tend to use heuristics derived from past experience and knowledge of structural features to improve mesh quality. We present a technique that tries to replicate this approach by detecting various MEMS features, and then meshing them based on an user-supplied rules file. This approach results in a FEA mesh that is computationally more efficient that conventional automeshers that have no knowledge of the geometry. The resulting computation time is found to be an order of magnitude faster than uniform meshing, with less than 5% difference in accuracy.