San Francisco, CA. A generic MEMS platform was one focus of CEA-Leti at SEMICON West. Philippe Robert, MEMS department director, said the organization is working seven days per week and 24 hours per day on sensors, actuators, RF components, packaging (including interposers), and characterization and reliability. More than 200 people work on MEMS technology, he said.
Leti, Robert said in an interview at the show, has more than 30 years background on MEMS sensors and has developed thin-film, bulk, surface, and nanoscale technology. Successful implementations have ranged from a weight sensor (Terraillon) in 1980 to a 9-axis M&NEMS platform in 2013, which, he said, is being transferred to Tronics. Tronics' goals are to implement a 6-DOF system on a 4-mm2 die in 2014-2015 and a 9-DOF version in 2015-2016.*
Robert elaborated on the “M&N” in the M&NEMS moniker used to describe the platform. The two letters (for micro and nano) allude to the two main issues of the MEMS world: first, the “universal” technology platform, and second, the miniaturization of the components. Shrinking seismic mass, Robert said, has a negative impact on sensitivity and lowers the signal-to-noise ratio in the case of capacitive detection. In order to address these problems, the M&N approach is based on a separate optimization between the “M” part that refers to maintaining the seismic mass at the micro scale, and the “N” part that refers to the optimized nano-sized piezoresistive gauge. The technology is applicable to 3-axes accelerometers, magnetometers, and gyroscopes (individually or for combo sensors) as well as a pressure sensor and high-SNR microphone are under development.*
Robert cited some commercially available products that employ Leti technology, including a NEMS-based gas sensor from APIX Technology. That sensor is 10 to 100 times smaller than other implementations and offers sub-ppm sensitivity. It serves industrial, security, environmental, and medical applications.
Also incorporating Leti technology is a PZT-based variable lens from Wavelens, which offers an optical aperture from 2.2 mm to 3 mm and features a better-than 3-ms response time. Offering power consumption of less than 100 µW, it finds use in camera phones, 2-D barcode readers, surveillance cameras, and camera pills.
Robert concluded by noting Leti holds 330 patents in the MEMS field and is adding 35 patents per year. The organization has 25 ongoing industrial collaborations and 10 long-term strategic partnerships. It has also seen 18 industrial transfers and the creation of five startups, including Tronics, APIX, and Wavelens as well as Primo1D and enerbee.
Robert gave a presentation on the platform at the LetiDay workshop held July 8 in conjunction with SEMICON West. Other presentations at the workshop included “M3D, a disruptive approach for further scaling”; New non-volatile memory technologies”; “Cost-effective lithography solutions for the future”; and “Wafer bonding solutions for new applications.”
*Edited for clarity, July 23, 2014.