Capacitive micro-electro-mechanical sensors with single crystal silicon electrodes

The devices presented herein are capacitive sensors with single crystal silicon on all key stress points. Isolating trenches are formed by trench and refill forming dielectrically isolated conductive silicon electrodes for drive, sense and guards. For pressure sensing devices according to the invention, the pressure port is opposed to the electrical wire bond pads for ease of packaging. Dual-axis accelerometers measuring in plane acceleration and out of plane acceleration are also described. A third axis in plane is easy to achieve by duplicating and rotating the accelerometer 90 degrees about its out of plane axis Creating resonant structures, angular rate sensors, bolometers, and many other structures are possible with this process technology. Key advantages are hermeticity, vertical vias, vertical and horizontal gap capability, single crystal materials, wafer level packaging, small size, high performance and low cost.