Sol-gel derived ferroelectric thin films in silicon micromachining

Abstract

Abstract Ferroelectric thin films have been integrated with silicon micromechanical structures in the fabrication of microsensor and microactuator structures. Both the piezoelectric and pyroelectric effects in thin films of lead zirconate titanate (Pb(ZrxTi1_x)O3) and lead titanate (PbTiO3) have been used for physical force sensing (pressure sensor), thermal heat sensing (pyroelectric infrared detector) and microactuation (mechanical positioner). Solid-state micromachining is used to form mechanical membranes on a silicon wafer for implementing easily deformable membranes or structures with a low thermal mass. This paper demonstrates the compatible simultaneous integration of 1) sol-gel deposited ferroelectric thin films, 2) surface-machined micromechanical structures and 3) n-well CMOS integrated circuit technologies.