Influence of air pressure on resonating and thermoelectric microstructures realized with standard IC technologies

We report the design and fabrication of resonant beam and thermoelectric pressure sensors realized on the same chip with industrial CMOS IC technology followed by anisotropic etching. Combining these two types of pressure sensors, we cover the measurement range between 10/sup -1/ Pa and 10/sup 5/ Pa. In the case of the cantilever beam resonator the influence of the air pressure on the fundamental resonance frequency and quality factor is studied. The results are compared with those obtained for a membrane resonator realized with bipolar IC technology. In case of the thermoelectric sensor, the influence of the air pressure on the temperature elevation of a heated, thermally isolated beam is investigated. We demonstrate IC process compatibility of such pressure sensing systems; this allows inexpensive batch fabrication and cointegration of circuitry.<
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