by Pawan Fangaria
The design and manufacture of MEMS is very different and in many ways more complex process than even the most advanced ICs. MEMS involve multiple degrees of freedom (i.e. the device to exhibit different characteristics under different physical state, motion or mechanics), making fabrication of MEMS extremely complex; and hence the processes are highly customized and typically linked to particular design or device. The process flow and design parameters are highly sensitive to each other, thus requiring multiple build-and-test cycles and longer MEMS process learning cycles. And these days most of electronic devices or semiconductor designs involve MEMS integrated into them, necessitating a MEMS+IC design approach. For example, gyroscopes are being used in smartphones in big way to enhance motion detection and orientation. Given the cut-throat competition in the mobile market, with increasing feature sets and shrinking windows of opportunity, it’s critical that process learning cycles for MEMS development move from time-consuming build-and-test methods to more efficient methodologies to streamline the handoff from design to manufacturing.
The good news is that Coventor’s SEMulator3D tool (about which I had earlier talked in the context of Virtual Fabrication Platform for semiconductor design ICs) is providing an excellent platform for virtual modeling of MEMS as well. Physical data (such as capacitance) can be extracted from the model for quantitative analysis and process variation studied to quickly predict the exact model of interest before actual fabrication, thus reducing the learning cycle for MEMS.