Abstract

Titanium nitride films of a thickness of 1.5 μm were deposited on amorphous and crystalline substrates by DC reactive magnetron sputtering at ambient temperature with 100% nitrogen in the sputter gas. The growth of nanostructured, i.e. crystalline nano-grain sized, films at ambient temperature is demonstrated. The microstructure of the films grown on crystalline substrates reveals a larger grain size/crystallite size than that of the films deposited on amorphous substrates. Specular reflectance measurements on films deposited on different substrates indicate that the position of the Ti–N 2s band at 2.33 eV is substrate-dependent, indicating substrate-mediated stoichiometry. This clearly demonstrates that not only structure and microstructure, but also chemical composition of the films is substrate-influenced. The films deposited on amorphous substrates display lower hardness and modulus values than the films deposited on crystalline substrates, with the highest value of hardness being 19 GPa on a lanthanum aluminate substrate.

Research highlights

► Titanium nitride films were deposited on borosilicate glass, quartz, silicon, stainless steel and lanthanum aluminate substrates. ► Films were deposited by DC reactive magnetron sputtering in 100% nitrogen atmosphere. ► Grain size, crystallite size and hardness of films were larger on crystalline substrates than on amorphous substrates. ► The position of the Ti–N 2s band at 2.33 eV is substrate-dependent, indicating substrate-mediated stoichiometry.