ABSTRACT
In high-power impulse magnetron sputtering (HiPIMS), the magnetron discharge power is applied in pulses with the peak power significantly exceeding the average power, often by about two orders of magnitude. To let the system cool down, long pauses of no or very low power are needed between pulses. The main purpose of high peak power is to ionize sputtered atoms in order to have additional means of tuning the properties of coatings. Ionization of sputtered atoms occurs primarily in ionization zones (“spokes”) drifting over the target along the racetrack. Many of the ionized target atoms return to the target causing self-sputtering. While self-sputtering facilitates the formation of dense plasma, it also reduces the deposition rate relative to the DC deposition rate at equal average discharge power. Much research focuses on the optimization of magnetic fields, involvement of one or more reactive gases, and programmed structuring of supplying power, e.g., the overlay of HiPIMS pulses and medium-frequency pulsing for the optimization of film properties and deposition rates.
