Micromechanic Pressure Sensors with Optical Readout and CMOS-Amplifiers on Silicon

Integrated microsystems consisting of membranes as pressure sensors, optical interferometers for readout, photodetectors and CMOS-amplifiers are integrated on one silicon chip applying only process steps typical in MOS technology. Membranes are crossed by the measurement branch of the Mach-Zehnder interferometer. Membrane elongation causes a refractive index change in the waveguide, so the interferometer output is modulated by an applied external pressure. Sensitivity achieved up to now is about 14 ¿V/mbar without electrical amplification.