| With the development of electron, information, and control technology, the characteristic of miniaturization and integration of devices demands new materials. The PZT film has become a new hot issue of functional materials and devices in the world due to its excellent performance of piezoelectricity, thermoelectricity, ferroelectric, photovoltaic and dielectric and the characteristic of integration with semiconductor process. PZT film is widely applied to the fields of microelectronics and optoelectronics, integrated photics and MEMS etc. And the characteristics of PZT film-high sensitive and high output strain make it a most promising material of drive devices in MEMS.In recent years, Sol-Gel method, which can produce excellent PZT films with close-knit structure, precise component and superior performance, is one of the newly developed methods in PZT film preparation. Therefore, Sol-Gel method has been widely applied to producing PZT ferroelectric film in modern MEMS so far. But the whole thickness of PZT film made by Sol-Gel method is not more than 2μm thickness, because the maximum thickness of no-crackle single layer can not exceed 120μm. As to 2~10μm or over 10μm, a better 0-3 compound method is developed on the base of the conventional Sol-Gel method preparation. By using 0-3 compound method, first we put 0 dimension PZT superfine mineral powder into 3 dimension PZT premonitory solution to get the equable and steady slurry, and then spin the shurry to form membrane. The 0-3 compound method has many merits, such as using simple equipment, thick enough film and good repetition.In this paper, the author analyze how to use Sol-Gel method to produce PZT micro-powder. With a lot of researches and analysis of technology of producing powder, we have grasped optimize method which can be used to produce Perovskite structure PZT micro-powder with abiosalt as raw material and single metal alcohol salt. The best technics condition is identified by XRD: 2 hours' annealing under 650 ℃ degree. In that case, we can get the Perovskite structure.SEM has established that the powder particle in the experiment is well-distributed and the diameter is about 100um.In the paper we present an improved Sol-Gel method, on the base of traditional Sol-Gel method we produce PZT ferroelectric membrane on a configuration of Au/Ti/SiO2/Si. we present a method-covering PZT Sol-Gel and the slurry mixed PZT powder on the membrane alternately. The surface of membrane is flat and no crackle with the thickness of 2μm. After repeating it several times, the PZT membrane can become thicker and thicker. By using this method, the thickness of membrane is increased. The method breaks the limitation of thickness, has the good property of repetition and has improved the quality of PZT membrane surface.We have made test and analysis on the electric properties of PZT membrane, which shows that symmetry of hysteresis loops is good, the corresponding nonlinear polarization Pr=50uC/cm2, coercivity Ec=50Kv/cm respectively. The surplus dielectric constant of PZT membrane decreases with the increase of frequency which is tested is up to ε r=1080, loss tangent tanδ=0.05. It indicates the PZT membrane owns excellence dielectric and ferroelectric property.Therefore, the PZT membrane obtained by 0-3 compound method has a lot of advantages, such as even flawless and good repetition. This method also raises the maximum thickness of single-layer PZT membrane. We can raise the total film thickness as a result of continuous repetition. In MEMS, the PZT membranes made by this method overcome the limitation of the film thickness. |
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