Design and fabrication of Si-based PZT film microforce sensor chip

In order to measure the micro-forces which are in the degree of milligrams, a novel micro-force sensor based on the Si-based lead zirconate titanate (PZT) piezoelectric micro-cantilever was designed and fabricated by MEMS technique. PZT piezoelectric thin films with various thicknesses (300~800 nm) were prepared by Sol-Gel method on Pt/Ti/SiO₂Si substrates. The films were well crystallized and had single perovskite phase structure. Preparation process, piezoelectric and ferroelectrics properties were studied. Three kinds of Si-based PZT film microcantilevers were fabricated by micromachining method. The cantilevers will bend when a force in milligrams degree is applied on the surface of the cantilevers. By measuring the charge of the electrodes, the microforce can be calculated. The work principle of the microforce sensor was studied and the systemic model was designed approximately.