Pure play foundries like TSMC are transforming the MEMS landscape
There’s little doubt that the MEMS ecosystem is changing quickly as these devices become ubiquitous, especially in consumer products. The cost and time pressures involved in developing cell phones, games, tablets and other high-growth and emerging MEMS-enabled products are re-shaping the traditional landscape of the MEMS business.
The most recent report from market research firm IHS on the MEMS manufacturing industry underscores the pace and significance of this evolution. The report counts a dozen pure-play foundries now offering MEMS manufacturing services, a dramatic difference than a decade ago when MEMS manufacturing was done almost entirely in-house at captive MEMS suppliers.
The fabless model that has been so successful in the IC business is now gaining real traction in the MEMS world, with companies benefitting from the faster time to market and lower cost model that foundries can offer – particularly smaller start-ups without the capital or expertise – or desire – to do their own manufacturing. Indeed, InvenSense, which is something of the poster child for fabless MEMS, is cited in the IHS report as being one of the key factors in TSMC’s astonishing 200% growth rate in MEMs in the past year – growth which places them atop the MEMS foundry rankings with $53 million in revenues just from MEMS products (note that TSMC has only been in the MEMS game since 2008). Overall, the MEMS foundry business grew 23% from 2010 to 2011.
The emergence of the foundry model in MEMS is ushering in a new era which will see the traditional concept of ‘one process, one product’ all but fade away. That model, once necessary because of a lack of any other options, is proving to be too expensive and time-consuming to meet the modern-day needs of MEMS customers. Yes, the top tier suppliers like ST, TI and Analog Devices continue to hold their own with their internal fabrication processes (although even they are looking toward fab-lite models to reduce their overhead and augment capacity). But with heavyweight foundries like TSMC and Global Foundries (which saw MEMS revenues grow 178% last year), along with specialty manufacturing suppliers like Silex and Teldyne Dalsa, offering capacity and expertise to smaller and nimble MEMs developers targeting specific and novel applications, we can expect even further growth from foundries.
There’s even more good news for foundries: MEMS can leverage excess available capacity in many older 8 inch wafer fabs and mature process technologies. They can also put to use equipment still needing to be amortized. That’s not to say that the MEMS foundries aren’t just doing the ‘easy stuff’ – they are pushing the lading edge, with successful development of devices such as 3-axis gyroscopes, 6-axis inertial measurement units (IMU) and optical MEMS, as well as specialty process technique like on through-silicon via (TSV) technology.
The ecosystem still needs to evolve more, with design tools from companies like Coventor critical to helping fuel growth by making MEMS design more efficient and automated. We, like many others, are also investing heavily in needed design ecosystem support, such as the development of PDKs, RDKs, reusable MEMS IP and reference flows to streamline the MEMS design process and make the handoff to manufacturing a reliable one.
But the bottom line from our viewpoint: the fabless model is happening now. Not only are we seeing continued adoption of our MEMS design tools by fabless MEMS companies, but the top four of Coventor’s foundry customers grew an average of 71% over the previous year, as they build PDKs, develop new processes and create MEMS-specific IP. We look forward to continuing our role in helping evolve this important aspect of the MEMS business.
Figure 1: A virtual model of a GAA FET showing residual SiGe after the channel release step. Process engineers have to make a trade-off between silicon loss and residual SiGe.(b) Variation in residual SiGe as a function of the channel width and etch lateral ratio. The higher the channel width, the higher the lateral ratio needed to etch away all the SiGe. Channel widths are shown as delta values from the nominal value of 30 nm.