Microstructure of titanium coatings controlled by pulse sequence in multipulse HiPIMS

The deposition rate, as well as the structure of a coating for a given magnetron sputtered material are determined by the plasma properties which are significantly dependent on the type of plasma generation. Single-pulse high power impulse magnetron sputtering (s-HiPIMS), multipulse HiPIMS (m-HiPIMS) with the same energy per pulse sequence and conventional direct current magnetron sputtering (DC-MS) were employed to deposit metallic Ti coatings. Varying the number of pulses in one pulse sequence in multipulse HiPIMS operation enables us to influence the ion fluxes on the substrate and the ionisation of the sputtered titanium. The grain size for the HiPIMS-deposited coatings was in the range of 5 to 25 nm depending on the number of pulses in the pulse sequence, whereas it was 15 nm for the coating prepared by the DC-MS. By the use of multipulse HiPIMS, it was also possible to achieve coatings with a smoother surface morphology and lower roughness as well rougher coatings with larger asperities and higher roughness compared to DC-MS. The texture and the deposition rate were significantly affected by the number of pulses, too.

Automated summary

The deposition rate and structure of a coating can be influenced by the plasma properties, which in turn depend on the type of plasma generation. Different pulsing methods like multipulse HiPIMS can result in coatings with finer grain sizes and smoother surfaces compared to conventional methods like DC-MS.