ICMCTF2009 Session F1-2: Advances in Characterization of Coatings and Thin Films

Wednesday, April 29, 2009 8:00 AM in Room Sunrise

Wednesday Morning

Start	Invited?	Item
8:00 AM	Invited	F1-2-1 Thin Film Studies by the Application of Complementary Techniques in Real Time A. Vantomme, D. Smeets, J. Demeulemeester (Katholieke University Leuven, Belgium); C. Detavernier (Universiteit Gent, Belgium); C.M. Comrie (University of Cape Town, South Africa); C.C. Theron (iThemba Labs, South Africa); C. Lavoie (T.J. Watson Research Center) Advanced coatings and thin films often exhibit a complex composition of several atomic species. The distribution, redistribution, diffusive and reactive properties of the individual species as well as their cooperative motion upon thermal agitation, has a distinct influence on overall thin film properties. X-ray diffraction (XRD), Rutherford backscattering spectrometry (RBS) and sheet resistance measurements have proven most valuable in the study of thin film properties as a function of thermal treatment. Conventionally, several specimens are subjected to different heat treatments and subsequently analyzed one by one for a complete overview of the response of a thin film to thermal annealing. Because of the discrete character of this approach, however, critical stages for the understanding of the development of thin film properties are easily overlooked. This problem is avoided by determining the specimen properties in real time, i.e. during annealing. Additionally, real-time measurements drastically decrease the workload, as kinetic parameters, for example, can be obtained from a single ramped annealing, while numerous specimens have to be analyzed in the conventional approach. To illustrate the strength and complementarity of these real-time techniques, we will present some examples of (ternary) silicide and germanide thin film growth by thermal annealing. We will illustrate that (i) the combination of real-time XRD, RBS and sheet resistance measurements allows to investigate the initial (nucleation controlled) as well as the advanced (diffusion controlled) stages of Co_1-xNi_xSi₂ formation, (ii) the real-time determination of Pt (re)distribution during Ni(Pt)Si formation reveals the influence of impurities on texture development and (iii) a complete understanding of the Pd-germanide formation process on different Ge surfaces can only be obtained by combining real-time XRD and RBS results.
8:40 AM		F1-2-4 Cathodoluminescent Properties and Phase Identification in Kappa- and Gamma-Alumina Coatings G. Pozina, F. Giuliani, L. Hultman (Linköping University, Sweden); H. Blomqvist, M. Collin, I. Reineck (Sandvik Tooling AB, Sweden) We have studied cathodoluminescence (CL) properties of alumina coatings commercially grown on cemented carbide substrates with an intermediate TiCN layer. Typical films of a PVD sputtered gamma-Al₂O₃ or a CVD produced kappa-Al₂O₃ have been characterized and compared before and after annealing. Heat treatment of alumina at temperatures exceeding 900°C results in phase transformation to the α-Al₂O₃. Practical use of CL for phase identification has been demonstrated for both γ- and κ-alumina. All phases have revealed a strong room temperature CL with different peak energies depending on the phase. Spatial resolution of phases on microscopic level is especially demonstrative for the annealed κ-Al₂O₃ coating with mixed alpha- and kappa-alumina. We have also characterized by mean of CL the flank wear cutting tools with the gamma-alumina coating and we have found that the CL spectra for the worn fac e demonstrated a high-energy shift, i.e. towards alpha-phase. We have observed an appearance of a new luminescent band centered at 2.4 eV, which is similar to the emission from a Ti-doped alpha-alumina film, which suggests diffusion of Ti in alumina under thermal conditions at the interface during cutting.