Stress and Texture Analysis in Thin Films and Coatings by X-Ray Diffraction
The thin and textured coatings present a double difficulty for characterization by conventional X-ray diffraction. Their shallow depth reduces the diffracted intensity and allows the interference of the underlying material. Frequently they present a crystallographic texture which limits the number of orientations that provide good intensity and induces anisotropy effects on their mechanical behavior. Reliable results can be determined using diffraction geometry of lowincidence angle. This paper describes the application of the technique to several films, characterized by thicknesses of the order of 1 μm and crystallographic textures. Examples are proposed of chromium films applied by PVD on molybdenum substrates, decorative electroplated coatings, and aluminum coatings used for interconnections in microelectronic circuits. The Cr films are 1.5 μm thick and exhibit a strong <100> fiber texture. The decorative coatings were studied both on the nickel undercoat and in the Cr top layer. Results are presented for chromium where tensile stresses and a <110> fiber texture were observed. The Al films are 1.0 μm thick. Some samples were heattreated at different annealing temperatures. Tensile stresses were always observed, which increase in the annealed samples.
Paula Maria Vilarinho
J.C.P. Pina, M. J. Marques, J.M.M. dos Santos, A. M. Dias, "Stress and Texture Analysis in Thin Films and Coatings by X-Ray Diffraction", Materials Science Forum, Vols. 514-516, pp. 1613-1617, 2006