Multiscale Surface Microtexture Analysis of CuNPs@a-C:H Thin Films

The sputtered copper nanoparticles (Cu NPs) on amorphous hydrogenated carbon films (CuNPs@a-C:H) were deposited on a glass substrate by the codeposition method of radio-frequency (RF)-sputtering and RF-plasma-enhanced chemical vapor deposition methods. The thin films were synthesized in different deposition times of 10, 15, 20, and 25 min while other parameters were constant. Rutherford back scattering measurements specified the atomic content of the thin films while the localized surface plasmon resonance peak was extracted from the UV-visible spectra. To investigate surface images, an atomic force microscope in noncontact mode was used to give valuable information for the stereometric, fractal, and particle analyses. The surface topography was computed based on the ISO 25178-2:2012 standard and the Abbott-Firestone curves; polar graphs were plotted for additional statistical information on the surface microtexture. The autocorrelation function and three-dimensional (3-D) surface texture interpreted surface topography, anisotropy ratio, and functional properties which help optimize the thin film's functional performance. The X-ray diffraction profile which was applied to investigate the crystalline structure confirmed copper as the major structural component with Cu(111) and Cu(002) peaks, the intensities of which were increased with the deposition time. Finally, particle analyses were applied to confirm the previously obtained results.