Ferroelectric microsensors and microactuators

Ferroelectric thin films have been integrated with silicon micromachined structures to form micromechanical pressure sensors and infrared detectors. These devices are based on the piezoelectric and pyroelectric effects in Pb(Zr_xTi_1-x)O₃ and PbTiO₃ thin films, respectively. Surface-micromachining techniques have been used to form structures which are easily deformable for mechanical force sensing or exhibit a low thermal mass and low thermal conductivity to the substrate for infrared detection applications. The ferroelectric and surface-micromachining technologies presented have been shown to be compatible with a 3-μm CMOS technology. Both microsensors and microactuators have been fabricated using ferroelectric thin-film technology. Representative examples in this work are a pyroelectric infrared detector array, acoustic pressure sensors, a micromechanical linear positioner, and a piezoelectric microactuator