Making more MEMS

STMicroelectronics said this week that it will increase its MEMS (Micro-Electro-Mechanical Systems) production capacity to more than three million sensors a day by the end of 2011 based on “exploding” demand from industrial, healthcare, and automotive customers.

Automotive applications for MEMS devices include airbags, navigation systems, electronic stability control, and tire pressure monitoring systems. The research firm IHS iSuppli identifies Bosch, DENSO, Freescale, Sensata, and Infineon as major suppliers of automotive MEMS devices. Freescale recently marked its tenth anniversary with MEMS partner CEA-Leti.

IHS iSuppli ranks ST as a leading supplier of MEMS devices for consumer and mobile applications but notes that the company has targeted non-safety critical automotive applications such as car alarms and navigation. ST now offers a high-g accelerometer for the airbag market, and the research firm believes ST will be able to leverage its manufacturing economies of scale.

ST said it began producing MEMS devices on 8-inch silicon wafers in 2006 and was among the first MEMS makers to do so.  It uses a surface micro-machining process called THELMA (Thick Epi-Poly Layer for Microactuators and Accelerometers) for manufacturing accelerometers and gyroscopes. The process combines variably thick and thin poly-silicon layers for structures and interconnections and is said to enable the integration of linear and angular mechanical elements in a single chip. A complementary process called VENSENS (‘Venice Sensor’) allows the integration of a cavity into mono-crystalline silicon, resulting in “ultra-compact” pressure sensors, according to ST.

Preparing Recommendations

The automotive MEMS market rebounded in 2010, according to IHS iSuppli, reaching 662.3 million units compared with 501.2 million units in 2009, but growth is expected to slow in 2011 as the market returns to normal growth levels. IHS iSuppli expects a 7.3 percent increase in shipments. Production should pick back up next year, and growth rates should exceed 13 percent by 2014.

New applications contributing to automotive MEMS sensor growth include gas sensors to control cabin air quality, infrared thermopiles for temperature monitoring, microbolometers for night-vision systems, and MEMS oscillators to boost rear-view cameras.