Wafer-scale growth of highly textured piezoelectric thin films by pulsed laser deposition for micro-scale sensors and actuators

M D Nguyen,G Roelof,T Aukes,G Rijnders,R Tiggelaar

doi:10.1088/1742-6596/922/1/012022

Abstract

Piezoelectric lead-zirconate-titanate (PZT) thin films were deposited on 4-inch (111)Pt/Ti/SiO2/Si(001) wafers using large-area pulsed laser deposition (PLD). This study was focused on the homogeneity in film thickness, microstructure, ferroelectric and piezoelectric properties of PZT thin films. The results indicated that the highly textured (001)-oriented PZT thin films with wafer-scale thickness homogeneity (990 nm ± 0.8%) were obtained. The films were fabricated into piezoelectric cantilevers through a MEMS microfabrication process. The measured longitudinal piezoelectric coefficient (d33f = 210 pm/V ± 1.6%) and piezoelectric transverse coefficient (e31f = -18.8 C/m2 ± 2.8%) were high and homogeneity across wafers. The high piezoelectric properties on Si wafers will extend industrial application of PZT thin films and further development of piezoMEMS.

Highlights

Pulsed laser deposition (PLD) differs from other physical vapour deposition techniques because of the very high kinetic energy of the ablated particles arriving at the substrate and the high deposition rate during each laser pulse
Already since 1965, Smith and Turner utilized a pulsed ruby laser to deposit the first vacuum deposited thin films [1], the pulsed laser deposition (PLD) technique is only widely known when Dijkkamp et al [2] were able to laser-deposit a thin film of YBa2Cu3O7-G, a high-temperature superconductor material, which was of superior quality to that of films deposited with alternative techniques
The thickness variation depends on the film thickness and it slightly increases with thicker films, for instance the 0.5 and 2μm-thick Piezoelectric lead-zirconate-titanate (PZT) films have the thickness variation of about 0.4 and 2.2%, respectively

Summary

Introduction

Pulsed laser deposition (PLD) differs from other physical vapour deposition techniques because of the very high kinetic energy of the ablated particles arriving at the substrate and the high deposition rate during each laser pulse. PLD is a powerful method which allows a thicker film to be fabricated in a short time due to the high deposition rate and the possibility to incorporate the process directly into a Si-production line [3, 4], for example in MEMS. Despite the fact that PLD technique has provided an excellent tool for producing high-quality multicomponent films, it has not yet fully emerged as a reproducible process for commercial thin-film applications.

Methods

Results

Conclusion