Crystallization of Pb(Zr,Ti)O3 films prepared by radio frequency magnetron sputtering with a stoichiometric oxide target

Abstract

Highly oriented and ferroelectric Pb(Zr,Ti)O3 (or PZT) thin films were obtained by radio frequency magnetron sputtering of a stoichiometric oxide target (Zr/Ti ratio of 53/47). No excess lead was used either during sputtering or during postdeposition annealing. Films deposited at 200 °C or below crystallize into a perovskite phase upon receiving anneal treatment at 590 °C or above. The annealing study, carried out using a conventional furnace, also revealed that the perovskite formation is completed during the first 5 min of annealing. The annealed films are highly (100) oriented on (111)-Pt coated oxidized Si substrates. Maximum polarization of 36 μC/cm2, remanent polarization of 20 μC/cm2, and coercive field of 22 kV/cm were obtained with excellent fatigue resistance. This suggests that the low thermal-budget process (i.e., low-temperature deposition and short-time anneal in a conventional furnace) with a stoichiometric oxide target may be appropriate as a reliable, simple, and economical method of preparing PZT films. Depositions at 500 °C or higher, however, resulted in TixOy or ZrTiO4 films, suggesting that lead was significantly lost during deposition.