Dresden 2006 – scientific programme

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DS: Dünne Schichten

DS 3: Thin film analysis I

DS 3.1: Invited Talk

Monday, March 27, 2006, 09:30–10:15, GER 38

X-ray diffraction analysis of residual stress fields in thin films - basic aspects and applications — •Christoph Genzel — Hahn-Meitner-Institut (c/o BESSY), Albert-Einstein-Straße 15, D-12489 Berlin

Thin films grown by physical or chemical vapour deposition have to meet various demands. The fields of application extend from wear protection of cutting tools to rather sophisticated superlattice structures used in microelectronics. At any rate, thin film deposition induces more or less high residual stresses in the growing layer, which influence the material properties to a great extent and therefore, have to be analysed carefully. In this connection X-ray diffraction takes up a key position, because it allows for a nondestructive and phase-selective investigation of the residual stress state. The application of well-established X-ray stress analysis (XSA) techniques to thin film systems, however, leads to a series of problems which are mainly due to the small layer thickness and the pronounced texture. Different approaches in thin film XSA are discussed with respect to their ability to a depth resolved evaluation of in-plane residual stress gradients within the layer (system). A useful criterion for classifying the individual methods is given by the way used to assign the measured diffraction signal to a certain information depth within the film. It will be shown, that both the so-called Laplace space methods, the depth resolution of which is based on the exponential beam attenuation, and the real space methods using a small volume gauge defined by narrow slits in the primary and the diffracted beam can be applied successfully to special cases in thin film stress gradient analysis.