Characterization of a novel micromachined accelerometer with enhanced-MIDOS

This paper reports the successful realization of a novel micromachined accelerometer with a highly sensitive in-plane optical motion sensor. Two arrays of CMOS integrated photodiodes are used to detect the motion of a matching micromachined suspended grid. Sub-angstrom displacements of the suspended grid are detected by the integrated readout electronics that amplify and subtract the resulting photocurrents from each array. The device is fabricated by deep reactive ion etching (DRIE) and then flip-chip bonded on the CMOS chip. A preliminary prototype with a natural frequency of 2500[Hz] exhibited a noise equivalent acceleration (NEA) of /spl sim/40[/spl mu/g//spl radic/(Hz)] and a dynamic range >90[dB] with linearity <0.1%.