Fabrication of PZT thick film on platinum-coated silicon substrate by an improved sol-gel deposition method

Abstract

This article has proposed the fabrication of thick films of lead zirconate titanate (PZT) on a Pt/Ti/SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /Si substrate using an improved sol-gel method. To achieve thicker PZT films within reasonable working time, this paper adopts sol-gel coating method but using PZT slurry which contains well dispersed and ball-milled sub-micrometer PZT powders in a sol-gel precursor solution. The PZT slurry is then spin-coated onto a substrate followed by pyrolysis thermal treatments. To enhancing the PZT film qualities, an improved vacuum infiltration treatment has been implemented in addition to conventional sol-gel coating and thermal processing. With the above-mentioned improvements, thicker PZT films with excellent characteristics are obtained. Microstructure and cross-section have been characterized by means of scanning electron microscopy (SEM). The ferroelectric property has been also determined by the ferroelectric analyzer. Films with a thickness in the range from 2.4 μm to 12.8 μm can be obtained within hours by the improved sol-gel method. When the thickness of the film is 12.8 μm, the maximum remanent polarization is 24.48 μC/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and the coercive field is 122.72 kV/cm at the maximum electric field, 625kV/cm. These PZT films are ready for device applications.