Polysilicon packaging and a new anchoring technology for thick SOI MEMS ynamic response model and application to over-damped inertial sensors

A new technology has been developed that combines high aspect ratio SOI surface micromachining with polysilicon packaging and a new nitride anchor process with robust release etch manufacturing margin. Based on an accurate damping model, the thickness of the SOI layer was defined to achieve an overdamped mechanical response and high performance on a low g accelerometer. Over-damping is required to filter the noise from parasitic vibration in automotive applications. This technology was designed for low cost and high performance inertial sensors.