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.