The effect of electrode composition on rf magnetron sputtering deposition of Pb[(Mg1/3Nb2/3)0.7Ti0.3]O3 films

Abstract

Ferroelectric Pb[(Mg1/3Nb2/3)0.7Ti0.3]O3 (abbreviated PMNT) thin films were prepared on silicon substrates by rf magnetron sputtering deposition with PbO-enriched PMNT targets. The effects of electrode composition and thin film growth conditions were investigated with grazing-incidence x-ray diffraction, secondary ion mass spectrometry, and scanning electron microscopy. The dielectric property of perovskite films was also measured. The usage of a Pt/Ti electrode was observed to enhance the formation of perovskite PMNT films; in addition, the TiO2 rutile phase was formed at the interface between the PMNT film and Pt electrode due to the oxidation of out-diffused Ti atoms from the inner Ti electrode. It was then noticed that if a target containing a larger excess of PbO was used, a higher consumption of TiO2 occurred and more perovskite phase would be formed in the deposited films. Consequently, perovskite PMNT films having a uniform microstructure and satisfactory dielectric property close to the bulk value were obtained by rf magnetron sputtering deposition on the Pt/Ti/SiO2/Si substrate at 640 °C under appropriate working conditions.