MEMS-Foundry Technology for High-Performance Gyroscopes
Published: Sep 2007
Using silicon-based MEMS technologies, the cost-efficient production of gyroscopes has become possible in recent years. As a result, gyroscopes are entering new markets, such as for highly accurate GPS-Instruments where the gyroscope enhances accuracy in situations where satellite reception is lost, for example in tunnels. However, since all gyroscopes are very precise resonating measurement devices, this leads to stringent wafer processing requirements for their production. Due to the growing market for different gyroscope applications, a MEMS Foundry Technology has been developed and established in production. It allows the manufacturing of moveable structures from the single crystalline silicon of a 15 μm thick device layer of a SOI wafer. By using filled insulation trenches and metal wiring, the parasitic capacities are reduced to a minimum. A glass frit bonded cap applied at the wafer level protects the sensitive mechanical structures and allows low pressure sealing, resulting in high Q-factors. This technology will be described in the following paper.