A year after announcing the industrialization of CEA-Leti’s breakthrough M&NEMS technologies, Tronics has successfully designed and manufactured the first batch of six-degrees-of-freedom (6DOF) MEMS chips, with 3 accelerometers and 3 gyroscopes on a single die (press release here). Built on SOI wafers, with a die size of less than 4mm2, this 6DOF MEMS chip is one of the smallest in the industry, and Tronics says further optimization will make it the smallest. Besides its size advantage, the piezoresistive nanowire based technology significantly decreases power consumption and allows manufacturing of all sensor types (accelerometers, gyroscopes, magnetometers, pressure sensor and microphone) using a common process flow.
This first functional batch is an important milestone towards high volume production. The industrialization work will continue through 2014, with the first commercial samples available in Q4 2014. An ASIC is also being designed and will be available in 2014 to complete the sensor platform. In addition to the 6DOF device, Tronics has also designed a very compact 9DOF monolithic MEMS. Samples will be available by the end of this year.
Target applications for this new generation of inertial devices are those where size and/or power are key: wearable devices, smartphones and tablets.
In the latest ASN posting by Dr. Eric Mounier of Yole Developpement, “SOI for MEMS: A Promising Material”, he notes that SOI MEMS is growing at a CAGR (2011-2015) of 15.6%, compared to 8.1% for bulk silicon-based solutions.
MEMS designers are doing amazing things on SOI – which would explain that impressive growth rate.
One of my favorites is Debiotech’s tiny insulin NanopumpTM targeting diabetes, fabbed by ST. As Debiotech’s Laurent-Dominique Piveteau noted, “…the use of SOI wafers for fabricating the Nanopump MEMS device has significant medical and economic advantages. The SOI-based structure allows for the highest reliability in the smallest possible package, enabling very tight control and precision of the pumping mechanism. The flow rate is steady, and it is insensitive to pressure, temperature, viscosity and aging. It also offers extreme dosing precision.”
Reasons cited by other contributors for using SOI for MEMS include:
But the bottom line is that it’s the most cost-effective solution for their state-of-the-art MEMS devices.
MEMS also figure in two of the most recent ASN Buzz postings:
In the next few weeks, we’ll also be posting a new article by Soitec on their Smart Stacking(tm) technology for the next generation of MEMS with pre-etched cavities, among other things.
If you’d like to see more of the why’s and wherefore’s of SOI-MEMS apps, just type “MEMS” into ASN’s search engine. You’ll get dozens of pieces from and about leaders like ST, ADI, Denso, VTI, Tronics, IBM and more.
It’s a pretty fragmented world, still, so if you know cool SOI-MEMS apps we should be covering, would you let me know?
A new Yole report highlights growth of SOI MEM S.
Although MEMS technologies are not driven by CD shrinking as ICs, that does not mean MEMS do not undergo strong technological evolutions. The ever-growing MEMS markets, today mostly driven by consumer applications, now have to be performance-driven, cost-driven and size driven.
SOI wafers are a promising substrate for MEMS manufacturing. We estimate the SOI market for MEMS devices will be close to $100M by 2015 (see Figure 1). That represents a CAGR (2011-2015) of 15.6% for SOI, compared to 8.1% for bulk silicon-based solutions.
One main reason for using SOI is to have more design freedom. Tronics, for example is using SOI with High Aspect Ratio Micromachining technology. This technology was developed to manufacture high performance custom inertial sensors (accelerometers and gyroscopes).
Other reasons cited for choosing an SOI-based solution for MEMS include the need for the smallest possible package, very tight control and precision of the structure, ability to withstand high pressure and temperature, long product lifetime, smallest possible die size and reduced cost.
Additional features in SOI wafers can further simplify MEMS design and manufacturing. For example, “cavity-SOI”, in which the SOI wafer has pre-etched cavities, enables the MEMS manufacturers to focus on their core competencies in reducing development time, which in turn can even lower production costs. Some MEMS manufacturers have found that pre-etched SOI cavities combined with dry etching simplifies the release of the devices.
MEMS manufacturers using cavity-SOI include VTI Technologies, Invensense and other players in the seismic accelerometer (Tronics) and pressure sensor markets.
Figure 2 shows a roadmap for SOI wafers for MEMS. From “traditional” SOI, we are now using SOI with pre-etched cavities. Further developments will allow the realization of SOI wafers with trench isolation, cavities and Through Silicon Vias (TSV).
Suppliers of other substrate solutions are following similar added-value paths. Glass, for example, can be used as a thin wafer carrier for wafer level capping and/or packaging with Through Glass Vias interconnect.
Overall, we believe substrates will provide additional functionalities in the future, enabling more integrated MEMS devices.
Tronics will produce high-performance, vacuum-packaged inertial MEMS accelerometers and gyroscopes invented, designed and patented by Thales, for the stringent navigation requirements of aircraft, satellites and other platforms.
Tronics, a leading global integrated manufacturer of custom SOI-MEMS, has received the 2009 Foundry of the Year Award from EuroAsia Semiconductor magazine. The editors cited Tronics’ history of profitability and growth, including expanding its capabilities and markets by forming a global group of companies in 2008, during the worldwide economic downturn.
“Tronics’ strategic expansions and our track record have extended our leadership in manufacturing high value-add custom MEMS products for both higher volumes and more diverse applications,” said Tronics’ CEO Peter Pfluger. “This award also recognizes our increasingly global presence with engineering and manufacturing operations in Europe and the U.S. and representation in China and Japan.”
SOI MEMS specialist Tronics and Alcatel Micro Machining Systems have entered into a JDP to develop next-generation deep reactive ion etching (DRIE) systems and process technology for high-performance custom sensors and actuators for the instrumentation, life sciences, automotive and aerospace industries.
A European leader in pacemakers relies on SOI based accelerometers to adapt pacing to activity level.
On the leading edge of medical technology, accelerometers that detect a person’s activity level are enabling major improvements in pacemakers and other cardiac devices. Pacemakers are used when the heart beats at incorrect levels; but of course, heartbeat varies with activity level. An accelerometer can detect tiny changes in movement and activity level. That information is then used to deliver the appropriate level of electrical stimuli to the patient’s heart. Read More
While microelectronics relies on SOI for its insulating layer, SOI-MEMS benefits from the single crystal silicon of the top layer and substrate. A good example is the latest product from TRONIC’S Microsystems, a French manufacturer of high-end custom components.
The geophone, a seismic vibration sensor manufactured for Sercel (the world leader in oil exploration equipment), benefits from the latest advances in SOI micromachining to reach resolution (mechanical noise) as low as 0.1µG. (Please see www.tronics-mst.com for a full case study.) Read More