Effect of Peak Current Density on Inner-wall Deposition of Ti Films by High-power Impulse Magnetron Sputtering

The variation of local deposition rate has been studied for Ti films deposited on the inner wall of holes with an entrance size of 2×2 mm2. The deposition was performed by high-power impulse magnetron sputtering (HiPIMS) under peak current densities of 0.3, 0.9, and 2.5 A/cm to investigate the transport behavior of sputtered ions and neutral particles into the holes and its effect on deposition rate distribution and microstructure of the films on the inner wall. Ti ion content in the plasma increased with increasing peak current density. As the ion content increased, the deposition rate tended to decrease and the film microstructure become denser regardless of the hole depth. Normalized deposition rate increased with increasing ion content when the hole depth was deeper than 4 mm. The effect of the ion content on the growth of Ti films deposited on the inner wall was demonstrated.