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Controlling the Wrinkling of the Bilayer Thin Films Electrothermally

Published online by Cambridge University Press:  01 February 2011

Shravan Chintapatla ,
John F. Muth  and
Leda M. Lunardi
Shravan Chintapatla
Affiliation:
schinta@ncsu.edu, North Carolina State University, Electrical and Computer Engineering, Raleigh, North Carolina, United States
John F. Muth
Affiliation:
muth@ncsu.edu, North Carolina State University, Electrical and Computer Engineering, Raleigh, North Carolina, United States
Leda M. Lunardi
Affiliation:
llunard@ncsu.edu, North Carolina State University, Electrical and Computer Engineering, Raleigh, North Carolina, United States
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Abstract

Wrinkling of thin sheets under strain is a universal phenomenon. The amplitude and period of the wrinkles formed in a thin sheet clamped at both ends are dependent on its strain and material parameters. In our study, wrinkling is observed in microscale for double clamped thin films (L>W>>t) consisting of 200nm deposited low stress silicon nitride bridges fabricated by bulk micromachining. A bilayer system is formed with 30nm aluminum evaporated on to these bridges. At room temperature the bridges are essentially flat. When an electrical current passes through the aluminum layer electrothermal, heating results in thermal expansion that wrinkles the bilayer. In addition we investigated various dimensions of the bridges and their correlation to the amplitude and the number of wrinkles. The observations are compared to existing wrinkling theory.

Keywords

elastic propertiesmicroelectro-mechanical (MEMS)thermal stresses
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1139: Symposium GG – Microelectromechanical Systems–Materials and Devices II , 2008 , 1139-GG03-20
Copyright
Copyright © Materials Research Society 2009

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References

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