In what may be a first for the MEMS industry, CEA-Leti has manufactured micro-accelerometers on 300mm wafers, a development that could lead to significantly lower MEMS manufacturing costs. And yes, those 300mm wafers are SOI wafers. These are “thick” SOI wafers, with an insulating BOx (buried oxide) layer of 2µm, and top silicon of 220nm.
The most advanced of Leti’s platforms is its M&NEMS technology based on detection by piezo-resistive silicon nanowires, which reduce sensor size and improve performances of multi-axis sensors. Leti’s inertial-sensor manufacturing concept enables the design and fabrication of combo sensors, such as three-axis accelerometers, three-axis gyroscopes and three-axis magnetometers on the same chip. This is a key component for IoT apps.
Leti’s M&NEMS concept, developed with 200mm technology, is currently being transferred to an industrial partner. Demonstration of this technology on 300mm wafers has shown very promising results.
In addition to lowering costs, manufacturing MEMS with 300mm technology enables 3D integration using MEMS CMOS processes in more advanced nodes than on 200mm, and the use of 3D through-silicon-vias (TSV), which is already available in 300mm technology. (Read the full Leti press release here.)