Fabrication of Ferroelectric Pb(Zr,Ti)O3 Thin Films by Liquid Delivery Metalorganic Chemical Vapor Deposition Using a Novel Titanium Source Ti(OEt)2(DPM)2

Abstract

Ferroelectric Pb(Zr,Ti)O3 (PZT) thin films were fabricated on platinized silicon substrates by liquid delivery metalorganic chemical vapor deposition (MOCVD) using Pb(DPM)2, Zr(DIBM)4 and Ti(OEt)2(DPM)2, and subsequent post annealing. Approximately 30% higher deposition rates were attained and the variation in the composition of the deposited films with changing substrate temperature was significantly suppressed using Ti(OEt)2(DPM)2 instead of Ti(OiPr)2(DPM)2. Although the films deposited at 400 and 450 °C were amorphous with PbPtx alloy as a secondary phase, they were crystallized into a perovskite PZT single phase with preferential 111 and 001/100 mixed orientations, respectively, by post annealing at 600 °C in air for 15 min. The 111-oriented PZT film with a thickness of 153 nm showed well-saturated and symmetric hysteresis properties with a twofold remanent polarization of 64.4 µC/cm2 and a twofold coercive field of 133.6 kV/cm. These results suggest that Ti(OEt)2(DPM)2 is a more suitable source than Ti(OiPr)2(DPM)2 for liquid delivery MOCVD of PZT thin films.