Open Access Nano Express

The Microscopic Origin of Residual Stress for Flat Self-Actuating Piezoelectric Cantilevers

Jeong Hoon Lee1, Kyo Seon Hwang2 and Tae Song Kim2*

Author affiliations

1 Department of Electrical Engineering, Kwangwoon University, Seoul, 139-701, Korea

2 Nano-Bio Research Center, Korea Institute of Science and Technology, Seoul, 136-791, Korea

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Citation and License

Nanoscale Res Lett 2011, 6:55  doi:10.1007/s11671-010-9810-z

Published: 30 September 2010

Abstract

In this study, flat piezoelectric microcantilevers were fabricated under low-stress Pb(Zr0.52Ti0.48)O3 (PZT) film conditions. They were analyzed using the Raman spectrum and wafer curvature methods. Based on the residual stress analysis, we found that a thickness of 1 μm was critical, since stress relaxation starts to occur at greater thicknesses, due to surface roughening. The (111) preferred orientation started to decrease when the film thickness was greater than 1 μm. The d33 value was closely related to the stress relaxation associated with the preferred orientation changes. We examined the harmonic response at different PZT cantilever lengths and obtained a 9.4-μm tip displacement at 3 Vp-p at 1 kHz. These analyses can provide a platform for the reliable operation of piezoelectric microdevices, potentially nanodevice when one needs to have simultaneous control of the residual stress and the piezoelectric properties.

Keywords:
Nanomechanics; Residual stress; Piezoelectric; Cantilever; Biosensor