Preparation of nanocomposite thin films by ion beam and plasma based sputtering processes

Experimental results on nanocomposite TiN/Cu and TiN/Si thin films by ion beam and plasma based sputtering processes are presented in this paper. Films were deposited on silicon (1 0 0) wafers not only by ion beam assisted sputtering deposition, in which the sputtered Ti and Cu and/or Si were deposited with simultaneous bombardment of nitrogen ions with different ion density, but also by d.c. magnetron co-sputtering of two pure elemental targets, where the substrate was negatively or positively biased. From TEM and XRD analyses it was verified that in both cases of nanocomposite formation TiN was composed of nanocrystallite of approximately 20–30 nm. The maximum hardness reached a value higher than 40 GPa in both cases. Hardness enhancement was observed in these TiN/Cu films with pronounced TiN (1 1 1) orientation and without diffraction peaks of crystal Cu in their X-ray diffractograms. However, the hardest TiN/Si film revealed randomly oriented TiN crystallites. The XPS spectra of Si 2p indicate that the Si atoms are mainly in Si3N4 form.