On November 12-15, 1995 a workshop sponsored by the National Science Foundation was held at the California Institute of Technology to discuss and explore the research issues involved in developing structured design methodologies for Micro-Electro-Mechanical Systems (MEMS). The Workshop gathered attendees from many of the major research universities involved in MEMS fabrication and MEMS design research, as well as several industry representatives. The goal of the Workshop was to identify areas of profitable fundamental research in the area of structured design methods for MEMS. The primary question posed to the Workshop was the following: Can the successes in developing structured design methods for digital VLSI be extended into the domain of MEMS? If so, what lessons can be learned and transferred?

The workshop attendees were divided into four discussion groups, and a series of questions were suggested to each group:

• The Synthesis group's discussion encompassed the development of methods for automatic or semi-automatic generation of MEMS shapes and/or masks.
  • What type of design rules can be defined that when applied to the representation will guarantee successful fabrication in a series of MEMS fabrication processes?
  • What shape synthesis tools are needed?
    • Can methods be developed to automatically create masks (and other fabrication information) to fabricate a desired shape?
  • What function synthesis tools are needed?
    • VLSI design has benefited by building complex functions from hierarchies of simpler elements, including automatic mapping of logical constructs into physical devices and physical placement of devices and wire routing
    • Can the same approach make progress towards automatic determination of shape(s) that will exhibit a desired function?
  • Can a methodology be developed to compile a schematic representation into masks and processing information to fabricate a device or system?
• The Function Simulation group considered approaches and requirements for simulation of the mechanical and electrical function of the resulting devices and systems.
  • What description(s) of function should be developed?
    • Should libraries of functional elements be compiled?
    • Should a small set of functional sub-elements be developed, from which more complex systems can be built?
  • What function simulation tools are needed?
    • Considerable work has been done on FEA of stress, strain, and electrical charge for MEMS.
    • What other simulation of function will be important?
• The Digital Data Interchange Languages group discussed the requirements for languages and standards for interchange of information between research, design, fabrication, and testing groups.
  • What level or levels of abstraction should be used for describing the physical design?
    • Should it be two-dimensional layers corresponding to the masks which are used during the fabrication process?
    • Or should it be a form of a three-dimensional description?
    • Or should it be a descriptive hierarchy with tools to move between the levels?
  • What type of model should be used to represent MEMS designs?
    • What should be the role of traditional solid modeling?
    • What attributes should the model provide in describing the design (in addition to geometry)?
    Potential candidates include strength, material, microstructure, tolerance, etc.
  • What should be the form of a digital design exchange format?
    • Can the format support alternative MEMS processes?
    • Is there a common set of information required by all MEMS processes?
    • What formats and design methodologies are in use today to support the MEMS processes and is there a generic methodology applicable to all (many of) the MEMS processes?
    • Is there some grouping of MEMS processes which will facilitate the identification of generic methodologies?
• The Fabrication Process Simulation group examined the requirements for the simulation of MEMS fabrication processes during the design process.
  • What fabrication simulation tools are needed?
    • The physical device is not a simple extrusion of the 2-D mask
    • Is there a need for fabrication process planning (or can a "clean separation" between the design activity and the fabrication details be maintained)?
    • Are design critics to identify non-manufacturable features a valuable approach?

These four groups met over the course of the four day workshop, with twice-daily meetings of the whole group for discussion and interchange. The reports of the four discussion groups are included in Section reports of this report. The whole-group discussions helped refine the group discussions, developed some common themes, and also generated an over-arching agreement on the necessity for some infrastructure development. A brief report on suggested infrastructure developments in included in Section reports.

A brief introduction to the background of this report is included in the next section, followed by brief summaries of each discussion group's findings and recommendations, followed by the full report of each group.

Each participant was encouraged to write a position paper in conjunction with the workshop. These are attached to this report in Section papers.