Composition-dependent changes in the NEXAFS spectra of TiN-Cu films

The nanostructure of Ti in TiN-Cu films, grown by pulsed laser deposition, is studied using Ti-K-NEXAFS spectroscopy. The characteristics of the NEXAFS spectra are strongly affected by both the different growth conditions and the Ti concentration in the films. More specifically, the area under the pre-edge peak is strongly correlated with the coordination number of Ti. It is found that in the TiN-Cu films grown from the intermetallic TiCu target, the area under the pre-edge peak decreases as the Ti concentration increases from 50 to 95 at.%. In the films grown from Ti and Cu elemental targets, the area under the pre-edge peak decreases as a function of the nitrogen partial pressure. The detected changes in the pre-edge peak can be attributed to the formation of Ti-Cu bonds.