High-power pulsed dc magnetron sputtering with an effective reactive gas flow control, was used for the reactive deposition of transparent zirconium dioxide films. The depositions were performed using a strongly unbalanced magnetron with a planar zirconium target of 100 mm diameter in argon-oxygen gas mixtures at the argon pressure of 2 Pa. The repetition frequency was 500 Hz at duty cycles ranging from 2.5 % to 10 %. The substrate temperatures were less than 300°C during the depositions of films on a floating substrate at the distance of 100 mm from the target. The increase in the average target power density from 5Wcm~(-2) to 100Wcm~(-2) in a period at the same duty cycle of 10 % resulted in a rapid rise in the deposition rate from 11 nm/min to 73 nm/min. However, the deposition rate per average target power density in a period decreased 3 times. The increased target power density in shortened voltage pulses (the duty cycle from 5 % to 2.5 %) at an average target power density of 50Wcm~(-2) in a period led to a reduced deposition rate from 64 nm/min to 15 nm/min. The zirconium dioxide films were found to be crystalline with a predominant monoclinic structure. Their extinction coefficient was between 6×10~(-4) and 4×10~(-3) (at 550 nm) and hardness between 10 GPa and 15 GPa.
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