Currently MEMS designers begin the geometric design of a new device by creating the masks that would lead to a geometric model. At the macro-level, this would be analogous to generating a geometric model from the tool paths, which would be a very tedious task. In contrast to MEMS designers, designers of macro-devices have the advantage of starting with a geometric model and of being able to directly visualize or manipulate their designs. The geometric model is then queried to generate manufacturing-related data. In the case of surface micromachined MEMS, until very recently, there has been no systematic means to automatically generate the mask data after a geometric model of the MEMS device has been refined through behavioral simulations. This has resulted in the lack of geometric design tools that would potentially aid the MEMS designer in creating MEMS devices.
This paper focuses on developing a declarative, feature-based design tool for the cross sectional design of surface micromachined MEMS, which enables MEMS designers to create fabrication-ready models of MEMS devices in an intuitive environment that is transparent to the fabrication process. The structured nature of MEMS fabrication processes has been exploited to develop a design-by-features approach tailored to MEMS design. In comparison to most macro-design tools where a design-by-features approach does not provide full flexibility, in the case of MEMS, the structured nature of the fabrication process allows for a comprehensive definition of design features that can be systematically mapped to fabrication features. In addition, feature dependency graphs and constraint graphs enable feature reparametrization leading to the easy manipulation of MEMS designs.