Effect of pyrolysis temperature on the properties of Bi3.5 La0.5Ti3O12 thin films deposited by aquous chemical solution deposition

Abstract

Bi3.5La0.5Ti3O12 thin films for ferroelectric random access memory application were fabricated by the aqueous chemical solution deposition method. The precursor films were deposited by spin coating and subsequently transformed into the oxide by thermal treatment on three hot plates and crystallizing in a rapid thermal processing furnace at a temperature as low as 650 °C. The temperature of the third hot plate step was varied, which affected the ferroelectric properties of the prepared films. The ferroelectric properties of the crystallized films as well as their crystallographic structure, texture and microstructure were characterized using various experimental techniques. The evolution of the precursor chemical structure of the thin films, containing organic compounds, was studied at different temperatures during the thermal treatment. In order to maximize the remanent polarization of the crystalline Bi3.5La0.5Ti3O12 thin films to approximately 6 μC cm−2 it is preferable to remove all the organic components of the thin-film precursor prior to the intermediate crystallization step in the rapid thermal processing furnace. A temperature of 370 °C has been shown to be the minimal temperature for achieving the complete decomposition of the organic constituents of the precursor thin film.