ANOMALOUS X-RAY REFLECTIVITY STUDY OF METAL-OXIDE THIN-FILMS

Anomalous X-ray reflectivity measurements have been performed to extra ct electron density profile as a function of depth. Using a model inde pendent analysis scheme based on distorted wave Born approximation, we have demonstrated that element-specific density profiles in a film ca n be obtained from reflectivity measurements done at two different X-r ay energies, one at an absorption edge of the corresponding metal and another one away from it. The merit of this technique has been demonst rated with the results on high dielectric constant metal oxide Ta2O5 f ilms on Si(001). Our results show different Ta profiles near interface s for Ta2O5/Si interface and Ta2O5/SiO2 interface, implying different kinetics at these interfaces during annealing process. (C) 1998 Elsevi er Science B.V. All rights reserved.