Phase composition of copper nitride coatings examined by the use of X-ray diffraction and Raman spectroscopy

The Cu-N layers were deposited on non-heated substrates by means of the pulsed magnetron sputtering (PMS) method. Conducted studies were focused on the structural properties characterization and were performed by using Raman spectroscopy and X-ray diffraction techniques. Based on these studies, especially taking into account the Raman band shift as a control parameter, classification of the Cu-N coatings in terms of their chemical composition and phase structure (stoichiometry, supersaturation) were performed. Obtained results point to the conclusion that polycrystalline structure of Cu-N layers depends on the Cu-content. When the Cu-content increases, recorded lattice constant changes from 0.3817 nm to 0.388 nm. This phenomenon is accompanied by deviation from stoichiometry of the Cu3N phase. At the same time, Raman band shift from 635 cm−1 to 610 cm−1 is observed. Thus, obtained results point to the conclusion that the Raman spectroscopy technique allows to determine the relation between deviation of the system from the phase equilibrium in the function of the band shift.