Orientation of rapid thermally annealed lead zirconate titanate thin films on (111) Pt substrates

Abstract

The nucleation, growth, and orientation of lead zirconate titanate thin films prepared from organometallic precursor solutions by spin coating on (111) oriented platinum substrates and crystallized by rapid thermal annealing was investigated. The effects of pyrolysis temperature, post-pyrolysis thermal treatments, and excess lead addition are reported. The use of post-pyrolysis oxygen anneals at temperatures in the regime of 350-450 °C was found to strongly affect the kinetics of subsequent amorphous-pyrochlore-perovskite crystallization by rapid thermal annealing. The use of such post-pyrolysis anneals allowed films of reproducible microstructure and textures [both (100) and (111)] to be prepared by rapid thermal annealing. It is proposed that such anneals and pyrolysis temperature affect the oxygen concentration/average Pb valence in the amorphous films prior to annealing. Such changes in the Pb valence state then affect the stability of the transient pyrochlore phase and thus the kinetics of perovskite crystallization.

Texture control of PbTiO3 and Pb(Zr,Ti)O3 thin films with TiO2 seeding

“…As platinum can be grown with a high degree of (111) texture, a (111) orientation of PZT is expected to be favored. It is usually found, however, that many different orientations can be obtained on Pt (111) [6]. In addition, it was shown by Aoki et al [7] that pure platinum is not the ideal substrate to nucleate the perovskite.…”

“…It turned out that such titania seed layers almost inevitably lead to a (111) texture, also when sol-gel deposition techniques are applied. The influence of the seed layer is stronger than that of process parameters such as pyrolysis and annealing temperature, heating rates, and lead excess, which usually are the parameters optimized for orientation control [6]. This seed layer already has been successfully applied for the fabrication of pyroelectric devices [12].…”

Determination of the Orientations and Microstructures of Pb(Zr,Ti)O Films Fabricated on Different Substrate Structures

“…In the case of the PZT film on a platinized Si substrate with a Pt film of (111) orientation, the PZT film has a (111)-preferred orientation after rapid thermal annealing. This is a reasonable result because the orientation of the PZT film is affected by the orientation of the (111)-Pt bottom electrode with a PbPt x (111) intermediate phase, (15,16) which leads to the lattice matching between PZT and Pt (111). However, the PZT film on the Pt membrane structure has a (001)-preferred orientation and even the Pt bottom electrode has a (111) orientation, under the same sputtering and annealing conditions, such as those of the PZT film on a platinized Si.…”

Fabrication and characterization of PZT thin-film vibrators for micromotors

“…The film exhibits a strong <111> texture. Details have been previously reported [8,9]. The sputtered PZT with <100> orientation was grown in situ from 3 simultaneously operating magnetrons with metal targets.…”