COMPARATIVE ANALYSIS FOR THE LOCAL PIEZOELECTRIC PROPERTIES OF ION BEAM AND REACTIVE ION BEAM ETCHED Pb(Zr,Ti)O3 THIN FILMS

Abstract

ABSTRACT Piezoelectric properties of highly (111)-oriented unetched, ion beam etched (IBE) and reactive ion beam etched (RIBE) PbZr0.35Ti0.65O3 (PZT) thin films have been investigated on the nanoscale by piezoelectric force microscopy. Crystallization of the films was performed before or after etching. Piezoelectric contrasts imaging reveals a clear modification of the domain architecture for all the films etched after crystallization; also, within grains, local piezoelectric hysteresis loops measurements show that coercive voltage increases about 130% (1.0 V to 2.3 V) for ion beam etched films while there is no significant change for reactive ion beam etched films. No evolution of coercive voltage is evidenced for films crystallized after ion beam etching. These results are explained in terms of domain-wall pinning in the film. Piezoelectric activity is shown to be similar for all the etched films; it is only slightly reduced of about 10% in comparison to the one measured for unetched film. On the other hand, theoretical considerations using a simple charge model indicate that the depth of the ellipsoid taken into account at the surface of the film for these measurements is about 20 nm.