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Title: Electrode size and boundary condition independent measurement of the effective piezoelectric coefficient of thin films

Journal Article · · APL materials
DOI:https://doi.org/10.1063/1.4907954· OSTI ID:22415252
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  1. National Physical Laboratory, Teddington, Middlesex TW11 0LW (United Kingdom)
  2. IBM Research Division, T. J. Watson Research Centre, Yorktown Heights, New York 10598 (United States)

The determination of the piezoelectric coefficient of thin films using interferometry is hindered by bending contributions. Using finite element analysis (FEA) simulations, we show that the Lefki and Dormans approximations using either single or double-beam measurements cannot be used with finite top electrode sizes. We introduce a novel method for characterising piezoelectric thin films which uses a differential measurement over the discontinuity at the electrode edge as an internal reference, thereby eliminating bending contributions. This step height is shown to be electrode size and boundary condition independent. An analytical expression is derived which gives good agreement with FEA predictions of the step height.

OSTI ID:
22415252
Journal Information:
APL materials, Vol. 3, Issue 2; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 2166-532X
Country of Publication:
United States
Language:
English