Investigation of interface properties of sputter deposited TiN/CrN superlattices by low angle x-ray reflectivity

Abstract

Approximately 1.8 µm thick nanolayered multilayer coatings of TiN/CrN (also known as superlattices) were deposited on silicon (1 0 0) substrates at different modulation wavelengths (4.6–12.8 nm), substrate temperatures (50–400 °C) and substrate bias voltages (−50 to −200 V) using a reactive direct current magnetron sputtering system. The x-ray reflectivity (XRR) technique was employed to determine various properties of the multilayers such as interface roughness, surface roughness, electron density, critical angle and individual layer thicknesses. The modulation wavelengths of the TiN/CrN superlattice coatings were calculated using a modified Bragg's law. Furthermore, the experimental XRR patterns were simulated using theoretically generated patterns and a good fit was obtained for a three layer model, i.e. (1) top surface roughness layer, (2) TiN/CrN multilayer coating (approximately 1.8 µm) and (3) Ti interlayer (∼0.5 µm) at the film–substrate interface. For the superlattice coatings prepared at a modulation wavelength of 9.7 nm, a substrate bias of −200 V and a substrate temperature of 400 °C the XRR patterns showed Bragg reflections up to 5th order, indicating well-defined periodicity of the constituent layers and relatively sharp interfaces. The simulation showed that the superlattice coatings prepared under the above conditions exhibited low surface and interface roughnesses. We also present the effect of substrate temperature and substrate bias, which are critical parameters for controlling the superlattice properties, onto the various interface properties of TiN/CrN superlattices.

Hard coating performance enhancement by using [Ti/TiN]n, [Zr/ZrN]n and [TiN/ZrN]n multilayer system

“…Fig. 2c shows the elemental compositions of deposited [TiN/ZrN] 12 multilayer film, where was observed the stoichiometric ratio (Ti/Zr = 1.32), which correspond to stoichiometric values from Ti and Zr elements in TiN/ZrN films [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. A careful correction has to be done in all stoichiometric analysis because EDX has low reliability for nitrogen concentration.…”

“…It is known that over the past decade, multilayered films of transition metal nitrides have received considerable interest for their outstanding properties within a narrow range of bilayer thicknesses [1]. Superior mechanical properties such as extreme hardness and good wear resistance have been reported [2,3].…”

Cation ordering within the perovskite block of a six-layer Ruddlesden-Popper oxide from layer-by-layer growth – artificial interfaces in complex unit cells

“…The calculation used is based on path-length calculations of interference in thin films. [50][51][52][53] A similar value (81 AE 2 nm) for the thickness was obtained from the Fast Fourier Transform (FFT) of the data. 54 The data were fit using the segmented fit algorithm.…”