Fabrication of thick Pb(Zr,Ti)O3 (PZT) films by modified sol–gel methods for application in MEMS

Abstract

Pb(Zr,Ti)O 3 (PZT) films with thickness ranging from 2 μm to 10 μm have successfully been prepared using the sol-gel-based ceramic-ceramic 0-3 composite method, polyvinylpyrrolidone (PVP)-assisted sol-gel method and electrostatic spray deposition (ESD) with satisfied film properties on Pt/Ti/SiO 2 /Si substrate. Using PVP and PZT powders as additives, the critical thickness of sol-gel derived PZT film can be sufficiently increased to 0.9 μm and 0.5 μm, respectively. The crystal-orientation of the films was investigated by X-ray diffractometer. It was found that the use of buffer layer was effective to affect the film's nucleation and growth behavior and enhance the pervoskite (100) orientation. According to the atomic force microscope images, these films exhibit uniform grain size distribution. The relative dielectric constants of the film prepared by these modified sol-gel techniques, 1050, 600 and 960, were measured, which are satisfied for application in MEMS.