Microelectromechanical systems: Tools make EDA MEMS-capable

Why does every company making microelectromechanical systems chips seem to have a MEMS expert? The answer, according to Mary Ann Maher, is that the current crop of electronic design automation tools doesn't have built-in MEMS capabilities. The company she founded, SoftMEMS LLC (Los Gatos, Calif.), is looking to change that. It is in the business of adding MEMS capabilities to EDA software, thus mitigating the need for MEMS experts.

"Our tools add MEMS design capabilities to your existing EDA software," said Maher. "There will always be a MEMS guru somewhere in the value chain, but we allow them to co-design with the EEs. And for already designed MEMS parts, our tools enable EEs to use that IP [intellectual property] without having to have the deep MEMS knowledge of a guru."

SoftMEMS' tool sets, called MEMS Xplorer (for Unix and HP platforms) and MEMS Pro (for Linux PC platforms), are plug-ins to EDA software offered by Cadence, Mentor, Synopsys and others. The tools add MEMS-specific menus that enable mixed MEMS/IC schematic capture and simulation; mask layout and verification; 3-D-model generation and visualization; behavioral-model creation; and links to MEMS analysis packages such as IntelliSuite, from IntelliSense Software Corp. (Woburn, Mass.) and CoventorWare, from Coventor Inc. (Cary, N.C.).

"EDA vendors don't really have tools that are specifically designed for MEMS. SoftMEMS focuses on adding design tools specifically for MEMS," said Jim Walker, vice president of research in semiconductor manufacturing at Gartner Dataquest. "IntelliSense and Coventor focus on analysis of MEMS design; they have some overlap with SoftMEMS but do not really consider themselves to be in competition with SoftMEMS."

By integrating its tools with existing EDA tool sets, SoftMEMS claims to be uniquely positioned to enable EEs to co-design electronics-with-MEMS-chips from the comfort of their familiar EDA platform. SoftMEMS' tools enable EEs to use general-purpose modeling and simulation tools from companies such as Ansys Inc. (Canonsburg, Pa.), but EEs can also choose MEMS-specific analysis tools from Intelli- Suite or Coventor. The products offered by the two latter companies are based on the pioneering MEMS analysis tools created at the Massachusetts Institute of Technology by EE professor Stephen Senturia in the 1990s.

"Both of us [IntelliSense and Coventor] are spin-offs from Prof. Senturia's lab at MIT," said Sandeep Akkaraju, chief executive officer of IntelliSense. "More recently, we've worked together with SoftMEMS to make sure our MEMS analysis, modeling and simulation tools work together with their design tools. We supply a complete MEMS tool set, and you can use our EDA Linker to create component models in VHDL, Simulink or Spice, but now we also work with SoftMEMS."

From here to there
Besides EDA tools, SoftMEMS' glue software can link to mechanical design and automation (MDA) tools from Ansys, Comsol Open Engineering, Dassault-Abaqus and MSC Software. General-purpose design tools from Ansoft, AutoCAD and Matlab can also be integrated with SoftMEMS glue software. "Our flows enable engineers to create MEMS chips that integrate with electronic circuits created with EDA tools and with mechanical devices made with MDA tools," said Maher.

"We also provide design kits and libraries that work with IC manufacturers' processes to enable engineers to efficiently realize MEMS chips at a variety of fabs," she said.