Properties of Pulsed Magnetron Sputtered TiO2 Coatings Grown under Different Magnetron Configurations and Power Deliver Modes

The mid-frequency (20–350 kHz) pulsed magnetron sputtering process has been reported as an enabling technology for the deposition of a wide range of commercially important coatings onto large area glass components. In this study, transparent titania (TiO2) coatings were deposited by reactive unbalanced magnetron sputtering in a Large Area rig built ‘in-house’ and designed to replicate an in-line coater. Deposition took place in continuous DC, pulsed DC (40, 100, 200 and 300 kHz) and AC (40 kHz) modes. The films were deposited under different magnetron configurations; single and dual planar magnetrons operated in conventional mode, and dual planar magnetrons operated in full-face erosion (FFE) mode. A calibration run was carried out for each setting to obtain the deposition rate. Then, a 1 µm thick coating was deposited onto float glass. During the sputtering process the substrates were reciprocated in a plane parallel with respect to the magnetron. The film properties were compared and assessed in terms of their structures, optical and mechanical properties using scanning electron microscopy (SEM), X-ray diffraction (XRD), spectrophotometry and nanoindentation testing. This paper compares the properties of TiO2 produced by DC, AC and pulsed DC magnetron sputtering using different magnetron configurations (static or FFE) and attempts to relate these properties to deposition parameters.