Comparison of thrusts imparted by a magnetron sputtering source operated in DC and high power impulse modes

The thrusts induced by the 45-mm-diameter DC and high power impulse magnetron sputtering [DC magnetron sputtering (DCMS) and high power impulse magnetron sputtering (HiPIMS)] sources are assessed by using the pendulum thrust balance, where the instantaneous discharge power for the HiPIMS is two orders of magnitude larger than that for the DCMS. The temporally averaged power of the HiPIMS is chosen as 50–150 W, being similar to the DCMS, by adjusting the duty cycle. The thrust-to-power ratios of 9.1 and 3.7 mN/kW are obtained for the DCMS and HiPIMS, respectively, by ejecting the copper target material via sputtering. A comparison between the thrust and the deposition rate of the copper film on a substrate implies that the flux and the velocity of the ejected material for the DCMS are larger and lower than those for the HiPIMS, respectively.