AVS 50th International Symposium
    Applied Surface Science Thursday Sessions
       Session AS-ThM

Paper AS-ThM9
XPS Study of Ultrathin Ferroelectric Films

Thursday, November 6, 2003, 11:00 am, Room 324/325

Session: Electron Spectroscopy
Presenter: L. Vanzetti, ITC-irst, Italy
Authors: L. Vanzetti, ITC-irst, Italy
M. Bersani, ITC-irst, Italy
M. Barozzi, ITC-irst, Italy
M. Anderle, ITC-irst, Italy
V. Nagarajan, University of Maryland
T. Zhao, University of Maryland
R. Ramesh, University of Maryland
Correspondent: Click to Email
Lead zirconate titanate (PZT) thin films have been extensively studied for potential application in nonvolatile memory devices, infrared sensors, and microelectromechanichal systems. In addition to compositional and structural factors, the impact of the thickness of the ferroelectric layer, and the interface quality have to be considered in understanding the structure-property relationship in PZT thin films. In this work we show results of our investigation on ultrathin ferroelectric films by XPS and SIMS. PbZr@sub 0.2@Ti@sub 0.8@O@sub 3@ films of varying thickness were deposited by pulsed laser deposition on SrRuO@sub 3@ buffered SrTiO@sub 3@ substrates. Ferroelectric measurements show that the switchable polarization drastically decreased as the PZT thickness is scaled down from 15 to 4 nm. XPS measurements on the two representative samples, 4 and 15nm thick, show that the composition of both films is the same. Moreover, the surface does not show rutenium segregation from the buffer layer. This result proves that the drop in the polarization is not due to a change in the film composition. In addition, we also show SIMS depth profiling for both films.