Effect of rare earth ions doping on properties of bismuth titanate thin films prepared by CDS method

Abstract

(Bi, La)₄Ti₃O₁₂ (BLT) is one of the most suitable materials for nonvolatile ferroelectric random access memories (FeRAMs), because this substance has excellent ferroelectric and fatigue-free properties. In this work, fabrication and characterization of (Bi, Ln)₄Ti₃O₁₂ [Ln:La, Nd, Sm, Gd,] thin films on substrates have been carried out by the chemical solution deposition process. Homogeneous and stable precursor solutions could be are prepared by controlling the reaction of starting metal alkoxide. A heat treatment above 600°C was required for the fabrication of (Bi, Ln)₄Ti₃O₁₂ thin films on Pt/Ti/SiO₂/Si substrates with high crystallinity. A crystallinity of the thin films was found to depend on substituent ions. Dielectric and ferroelectric properties of synthesized films were also evaluated.