Noncontact quantitative spatial mapping of stress and flexural rigidity in thin membranes using a picosecond transient grating photoacoustic technique.
This paper describes a purely optical technique for measuring and spatially mapping out stress and rigidity in thin membranes. Its application to a membrane of aluminum nitride that has significant spatial nonuniformities in its elastic properties demonstrates the method. The attractive features of this technique--fast, noncontacting measurement, good spatial resolution, ability to quantify in-plane anisotropy--make it potentially useful for characterizing elements of microelectromechanical structures, masks for advanced lithography systems, acoustic filters, and other devices in which the mechanical properties of membranes are important.
Bell Laboratories, Lucent Technologies, Murray Hill, New Jersey 07974, USA. jarogers@physics.lucent.com
J A
JA
Rogers
G R
GR
Bogart
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RE
Miller