Citation:
J. Ricotea, S. Holgado, Z. Huang, P. Ramos, R. Fernández and M.L. Calzada, Fabrication of continuous ultrathin ferroelectric films by chemical solution deposition methods, Journal of Materials Research, Volume 23, Number 10, October 2008, Pages 2787-2795
Abstract:
The integration of ferroelectrics in nanodevices requires firstly the preparation of
high-quality ultrathin films. Chemical solution deposition is considered a rapid and
cost-effective technique for preparing high-quality oxide films, but one that has
traditionally been regarded as unsuitable, or at least challenging, for fabricating films
with good properties and thickness below 100 nm. In the present work we explore the
deposition of highly diluted solutions of pure and Ca-modified lead titanates to prepare
ultrathin ferroelectric films, the thickness of which is controlled by the concentration
of the precursor solution. The results show that we are able to obtain single crystalline
phase continuous films down to 18 nm thickness, one of the lowest reported using
these methods. Below that thickness, the films start to be discontinuous, which is
attributed to a microstructural instability that can be controlled by an adequate tailoring
of the processing conditions. The effect of the reduction of thickness on the
piezoelectric behavior is studied by piezoresponse force microscopy. The results
indicate that films retain a significant piezoelectric activity regardless of their low
thickness, which is promising for their eventual integration in nanodevices, for
example, as transducer elements in nanoelectromechanical systems.
