Processing Effects for Integrated PZT: Residual Stress, Thickness, and Dielectric Properties

A series-capacitor model accounted for the observed dilution in room-temperature K from >900 to ∼600 as film thickness decreased, but could not account for the absence of the expected dielectric anomaly at high temperatures. Instead, a stress-induced distributed phase transformation related to the polycrystalline nature of the film was proposed to account for the observed behavior. Residual stress reduced the spontaneous polarization values in these specimens to 32muC/cm 2 from the predicted stress-free value of 50muC/cm2. An increase in coercive field was attributed to interfacial capacitance and residual stress, whereas a decrease of 30MPa tensile stress resulted in an increase of d33 from 33 to 65pm/V, irrespective of changes in film thickness. These results isolated, for the first time, the effects of stress and thickness on the dielectric, ferroelectric and piezoelectric properties of PZT films without convolution from the other major variables. The research provides a guideline for the tailoring of properties by modifying mechanical stress in polarizable and deformable thin films.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Materials Science and Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Ong, Ryan Jason

Contributors dc:contributor

• Payne, David A.

• Engineering, Materials Science

Language dc:language

eng

Identifier

(MiAaPQ)AAI3182340

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/82764