Growth and Characterisation of Pb(Zr,Ti)O3Films Deposited by Reactive Sputtering of Metallic Targets

Abstract

Ferroelectric (PZT) thin films have been deposited by dc reactive sputtering of a multi-element metal target. The sputtering of a metal target over an oxide target provides the feasibility for controlling the stoichiometry of PZT films by adjusting the surface areas of Pb, Zr, and Ti at the target. The structure of the resulting films without substrate heating was found to be polycrystalline with small and strained grains. Larger grain sizes, from 5 to 20 nm, were observed for sputtered films at higher pressure and higher substrate temperature. Post-deposition annealing resulted in a perovskite structure with a strong (110) texture and a corresponding grain size larger than 100 nm. The films were transparent, with refractive indices from 2 to 2 . 3 T e dc conductivity at 2 5 O C was 9.8~10-l1 fi -'an-'. PZT films showed an increase in relative permittivity of a factor 3 in terms of temperature, thus demonstrating their ferroelectric properties.