High-precision silicon differential pressure sensor monolithically integrated with twin diaphragms and micro over-range protection structures

This paper describes a novel silicon differential pressure sensor that is fabricated using silicon surface micromachining, monolithically integrated with twin diaphragms, and has lateral openings for leading the substances the pressures of which are to be measured, and micro over-range protection structures. The two diaphragms that have piezo gauge resistors work complementarily to each other as a result of a difference in the respective pressures of fluids led through the lateral openings. The sensor linearity and errors caused by changes in ambient temperature and static pressure have been improved to less than 0.2%, and high zero-point long-term stability of less than 0.01% has been obtained. Throughout this paper we will demonstrate the design for differential pressure sensors and show experimental results.