Fraunhofer-Gesellschaft

Publica

Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Bestimmung des E-Moduls dünner Schichten mit Ultraschalloberflächenwellen

Determination of Young's modulus of thin films by ultrasonic surface waves
 
: Schneider, D.; Schultrich, B.; Scheibe, H.J.

Hecht, G. ; Societe Francaise du Vide -SFV-, Paris; Deutsche Vakuum-Gesellschaft:
Thin Films. Proceedings of the joint 4th International Symposium on Trends and New Applications in Thin Films TATF '94 and the 11th Conference on High Vacuum, Interfaces and Thin Films HVITF '94
Oberursel: DGM-Informationsgesellschaft, 1994
ISBN: 3-88355-199-6
pp.378-381
International Symposium on Trends and New Applications in Thin Films (TATF) <4, 1994, Dresden>
Conference on High Vacuum, Interfaces and Thin Films (HVITF) <11, 1994, Dresden>
German
Conference Paper
Fraunhofer IWS ()
amorphe Kohlenstoffschicht; amorphous carbon film; E-Modul; film thickness; measurement method; measurement procedure; Meßmethode; Meßregime; Schichtdicke; Ultraschalloberflächenwelle; ultrasonic surface wave; Young's modulus

Abstract
A method has been developed to determine YOUNG'S modulus and thickness of thin surface layers by measuring the phase velocity of ultrasonic surface waves. These are thermoelastically induced by a short laser pulse. From the received pulse form in dependence on measuring distance, the phase velocity is determined over a sufficient wide frequency range by a special measuring and computational procedure. By comparing experimental and theoretical dispersion curves, YOUNG'S modulus and/or the thickness can be obtained without any calibration. The potential of this nondestructive method has been demonstrated for amorphous carbon films of less than 1 micrometer thickness, prepared by vacuum arc deposition. It has been found that the elastic constants responds sensitively to variation of preparation conditions. The ultrasonic method turned out to be a suitable means for characterizing thin films.

: http://publica.fraunhofer.de/documents/PX-6363.html