The use of surface acoustic waves in a scanning laser acoustic microscope for the characterization of the mechanical or acoustic properties of thin films deposited on piezoelectric substrates is demonstrated. Quanitative measurements of mass loading effects of 5000-Å-thick tungsten films deposited on lithium niobate substrates were obtained using 100-MHz surface acoustic waves. No information about the tungsten film could be obtained using 100-MHz compressional waves. Methods of generating surface waves on nonpiezoelectric materials so that this technique could be used on arbitrary substrates is discussed.
|Original language||English (US)|
|Number of pages||7|
|Journal||IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control|
|State||Published - Jul 1988|
Bibliographical noteFunding Information:
Manuscript Paper received December 11, 1986; revised April 23, 1987. This work supported in part by the Semiconductor Research Corporation under SCR grant 83-01-024 and in part by the Microelectronic and Information Sciences Center of the University of Minnesota. The authors are with the Department of Electrical Engineering, University of Minnesota, 123 Churh Street, Minneapolis, MY 55455. IEEE Log Number 8719103.