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DS: Dünne Schichten
DS 21: Mechanische Eigenschaften
DS 21.2: Vortrag
Donnerstag, 27. März 2003, 11:15–11:30, GER/38
Investigation of residual stress in diamond-like carbon films by Raman spectroscopy and X-ray methods — •Rhena Krawietz1, Bernd Kämpfe2, Ellen Auerswald2, and Marcus Brücher3 — 1HTW Dresden (FH), 01069 Dresden — 2Fraunhofer IZM Berlin, 13355 Berlin — 3Fraunhofer IPK Berlin, 110587 Berlin
The characterization of the stress state is important to evaluate the
reliability of devices based on diamond-like carbon (DLC) films. Both
Raman-spectroscopic and X-ray investigations allow non-destructive analysis
of materials. Using X-ray diffraction as analytical tool, the change of
lattice spacings due to the occurrence of strains is measured. So the only
requirement for the X-ray diffraction method is a crystalline state of
specimen.
Raman spectroscopy is restricted to materials showing intensive and sharp
Raman peaks but offers the possibility to measure stress profiles with
lateral resolution of 1 micron. Residual stresses can be determined by
measuring the shift of the Raman lines in comparison with stress-free
materials. The results of stress measurements using X-ray diffraction and
Raman spectroscopy at the same DLC films are in very good
correspondence.
Stresses in diamond films with very small crystallite sizes on silicon
substrates have been analysed by etching vertical edges in the film and by
measuring the stress profile in the substrate near this edges. The mean
stress in the film has been determined by fitting of a finite element model
to the measured profiles.