MSM 98
MSM 98
Technical Proceedings of the 1998 International Conference on Modeling and Simulation of Microsystems

Bulk and Topography Processing Chapter 2

Computer Aided Mask-Layout for Bulk Etch Fabrication

Authors: M.K Long, J.W. Burdick and E.K. Antonsson

Affilation: California Institute of Technology, United States

Pages: 35 - 40

Keywords: anisotropic etching, mask-layout, bulk etching, wet etching, KOH, EDP, TMAH, photo-lithography

This paper presents a method to synthesize the mask layout geometry for a MEMS wet etching process. Given a desired part geometry, the method determines a candidate mask geometry that will etch to the final desired shape, even in the case of highly anisotropic etchants. It will also compute compensation structures for difflcult to etch features. In cases where there does not exist a mask geometry that will etch to the desired feature, an approximate shape is produced. Conceptually, the algorithm is based on the use of a forward etch simulation in reverse time. Since the forward etch process is a many-to-one map, the reverse time simulation is augmented to include the set of valid preimages. While the methods are not inherently restricted to planar geometry, our discussion is limited to the case of planar polygonal feature geometries.

ISBN: 0-96661-35-0-3
Pages: 678