Theoretical analysis and measurement of the temperature dependence of a micromachined Fabry-Perot pressure sensor

In this study an analytical model that takes into account the coupled photoelastic and thermo-optical effects is established to evaluate the temperature dependence of a single-chip silicon micromachined Fabry-Perot pressure sensor. The results show that temperature variation has a significant effect on the performance of a micromachined Fabry-Perot pressure sensor with a conventional flat diaphragm. A new membrane-type silicon micromachined Fabry-Perot pressure sensor with a novel deeply corrugated diaphragm is then proposed. The sensor is fabricated on a single-chip by use of both surface- and bulk-micromachining techniques. Both analytical and experimental results show that the cross sensitivity of Fabry-Perot pressure sensors to temperature can be substantially alleviated by use of the proposed single deeply corrugated diaphragm.