Phase formations and ferroelectric properties of PLT thin films by MOCVD

Abstract

La-modified lead titanate, Pb_1-x La _x TiO₃(PLT), thin films were prepared on Si[100] and Pt/SiO₂/Si substrates by the low-pressure metalorganic chemical vapor deposition (LP-MOCVD) method with the hot-wall type. The PLT films were deposited at 500°C with the low-pressure of 0.1 Torr, and then annealed at 650°C with an oxygen ambient for 10 minutes. Irrespective of substrate properties and La molar fractions, the films revealed the [100] preferred-orientation. With increasing the La mole %(up to 34%) in the films, the surface morphology improved, and the ferroelectricity and the leakage current density decreased. On the other hand, up to the La 22 mole%, the relative dielectric constant increased from 900 to 1200.

Key Words:

• keywords:
• PLT
• ferroelectric
• MOCVD