Scaling effect on statistical behavior of switching parameters of ferroelectric capacitors

Authors

• Alexei Gruverman, University of Nebraska-LincolnFollow
• , University of Nebraska-Lincoln

Document Type

Article

Date of this Version

September 1999

Comments

Published in Appl. Phys. Lett., Vol. 75, No. 10, 6 September 1999. Copyright © 1999 American Institute of Physics. Used by permission.

Abstract

Scanning force microscopy (SFM) has been used to study nanoscale variations in switching parameters in layered perovskite films of SrBi₂Ta₂O₉ and to investigate the effect of capacitor scaling on the standard deviation of the capacitors’ integral polarization signal. Ferroelectric poling and SFM piezoresponse imaging were performed in a number of regions on the film surface sized 2x2, 1x1, 0.5x0.5, and 0.3x0.3 μm² with subsequent statistical analysis of the obtained data. It has been found that variations of the polarization signal can be approximated by the normal distribution function. The standard deviation increases with the decrease in the capacitor size, suggesting a stronger effect of grain misalignment in smaller capacitors. The obtained results imply that reliable high-density ferroelectric memories cannot be realized unless a certain capacitor size/ grain size ratio is maintained.