Grazing-emission X-Ray Fluorescence (GE-XRF) Method for Interfacial Diffusion Studies on Multi-Layered Thin Films

C. A. PÉREZ; H. J. SÁNCHEZ; A. GOBBI

Campinas

Congreso; RAU XXI; 2011

Surface characterization techniques often need spatial resolution in order to be ableto analyze their properties in different points. This is actually an intrinsic lim-itation of the grazing-incidence (GI) excitation condition in which the collectedinformation normally comes from a large area of the sample surface.The grazing-emission (GE) experiments provide the same information as (GI) ex-periments, according to the optical reciprocity theorem but, since in this case theexcitation is normal to the sample surface, the combination of GE-XRF and syn-chrotron x-ray microprobe permits surface-sensitive analysis with spatial resolution.In this work we have been exploiting the depth profiling capability of the GE-XRF technique, close to the critical angle, to study the interfacial diffusion of aCr/Au/Cr system at a specific location on the surface. For this purpose, Cr andAu thin films with thicknesses of 40nm and 20nm respectively were sputtered ontoa silicon substrate so as to create a patterns of layered thin films. Measurementswere performed on samples as deposited, as well as on those thermally treated to200oC and 400oC in order to induce interfacial diffusion. The results show a clearlychange in the GE-XRF curve for samples treated to 400oC.Moreover, the theoreti-cal model used to simulate the experimental data indicates that diffusion effect mustbe also considered for the non-thermally treated samples.Acknowledgements: This work was supported by the LNLS.