Browsing by Author "Rakocevic, Z."

Modification in structural and optical properties of chromium-nitride (CrN) films induced by argon ion irradiation and thermal annealings were investigated using various experimental techniques. CrN films deposited by d.c. reactive sputtering on Si substrate were implanted with 200 keV argon ions, at fluences of 5-20 x 10(15) ions/cm(2). As-implanted samples were then annealed in vacuum, for 2 h at 700 degrees C. Rutherford backscattering spectrometry, X-ray diffraction, cross-sectional (high-resolution) transmission electron microscopy and spectroscopic ellipsometry (SE) measurements were carried out in order to study structural and optical properties of the layers. After irradiation with 200 keV Ar ions a damaged surface layer of nanocrystalline structure was generated, which extended beyond the implantation profile, but left an undamaged bottom zone. Partial loss of columnar structure observed in implanted samples was recovered after annealing at 700 degrees C and CrN started to decompose to Cr2N. This layer geometry determined from transmission electron microscopy was inferred in the analysis of SE data using the combined Drude and Tauc-Lorentz model, and the variation of the optical bandgap was deduced. The results are discussed on the basis of the changes induced in the microstructure. It was found that the optical properties of the layers are strongly dependent on the defects' concentration of CrN. (C) 2016 Elsevier B.V. All rights reserved.

The present study deals with irradiation effects induced by xenon ions (Xe+ on titanium nitride (TiN) thin films. TiN films thickness of 260 urn obtained by using dc reactive sputtering were irradiated with 400 keV Xe ions. The irradiation doses were 5 x 10(15), 10 x 10(15), 15 x 10(15) and 20 x 10(15) ions/cm(2). The properties of irradiated films varying with ion fluence are investigated by means of Rutherford backscattering spectrometry, X-ray diffraction, transmission electron microscopy and spectroscopic ellipsometry. It was found that the Xe ions induce contraction and rhombohedral distortion of TiN lattice. The columnar structure was partially destroyed after irradiation, which introduce up to 1.5 at.% of Xe within the structure mostly concentrated around the projected ion range. The generation of defects due to the presence of heavy ions changes the optical constants of implanted films. It was found that the optical band gap of TiN films was reduced after xenon ion implantation. (C) 2017 Elsevier Ltd. All rights reserved.