Growth of Ti-C nanocomposite films by reactive high power impulse magnetron sputtering under industrial conditions

Titanium carbide (TiC) films were deposited employing high power impulse magnetron sputtering (HiPIMS) and direct current magnetron sputtering (DCMS) in an Ar–C 2H 2 atmosphere of various compositions. Analysis of the structural, bonding and compositional characteristics revealed that the deposited films are either TiC and hydrogenated amorphous carbon (a-C:H) nanocomposites, nanocrystalline TiC, or Ti/TiC, depending on the C/Ti ratio. It was found that Ti-C films grown by HiPIMS show a C/Ti ratio of close to 1 for a wide C 2H 2 flow range (4–15 sccm), with free C ranging from 0 to 20%. Thus, films ranging from near stoichiometric single phase TiC to TiC/a-C:H nanocomposites can be synthesized. This was not the case for DCMS, where films grown using similar deposition rates as for HiPIMS formed larger fractions of amorphous C matrix, thus being nanocomposites in the same C 2H 2 (above 4 sccm) flow range. For a C/Ti ratio of 1 the resistivity is low (4–8 × 10 2 μΩ cm) for the HiPIMS films, and high (> 100 × 10 2 μΩ cm) for the DCMS films. The hardness also shows a big difference with 20–27 and 6–10 GPa for HiPIMS and DCMS grown films, respectively. ► Reactive high power impulse magnetron sputtering of Ti-C demonstrated ► Composition close to stoichiometry for a wide range of reactive gas flows ► Stable process, facilitating coatings ranging from nc-TiC to nanocomposite TiC/a-C