XRD, HRTEM AND FIB-SIMS STUDY OF INTERFACES IN TiN/Cu MULTILAYERED THIN FILMS

摘要

This paper reports on the characterization of the interfaces in TiN/Cu multilayered thin films. The films were deposited by dual ion beam sputtering with modulation periods (A) ranging from 5 to 50 nm. X-ray diffraction provided information on the global multilayer structure, revealing a [002]-out-of-plane texture. High Resolution Transmission Electron Microscopy showed the presence of several interfacial and growth defects, such as misfit dislocations and micro-twins, formed to relax the huge misfit (15.9 percent) between the two fee lattices, and a cube-on-cube epitaxial growth, with semi-coherent interfaces. The presence of a growth front facetted morphology in Cu is revealed, leading to lateral interfacial roughness and fluctuations in the interplanar spacings. Ultimately, by Focused Ion Beam Secondary Ion Mass Spectrometry preliminary depth profiles were obtained with the aim to gain a comprehensive picture of the interfacial properties in terms of interface roughness and elemental distribution at the interfaces.