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Resonating Microelectromechanical Structures for Metrology

Published online by Cambridge University Press:  17 March 2011

A. M. Allen  and
G. C. Johnson
A. M. Allen
Affiliation:
Department of Mechanical Engineering University of California, Berkeley, CA 94720-1740, U.S.A.
G. C. Johnson
Affiliation:
Department of Mechanical Engineering University of California, Berkeley, CA 94720-1740, U.S.A.
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Abstract

A method for determining geometric process errors in MEMS devices from the resonant fre- quencies of simple structures is presented. The ability to accurately determine the as-built ge- ometry of MEMS devices is important given the magnitude of the geometric uncertainty relative to the dimensions of these devices. As MEMS become smaller, the need for reliable metrology becomes even more important. The method presented here provides a way to determine the etch offset (the difference between the design width of a planar feature and the as-built width), the average angle of the side-walls and the compliance of the support of the structure. An important feature of the approach presented is that by using frequency ratios for various structural modes, neither the elastic modulus nor the mass density of the film need be known.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 657: Symposia EE – Materials Science of Microelectromechanical Systems (MEMS) Devices III , 2000 , EE1.4
Copyright
Copyright © Materials Research Society 2001

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References

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