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

Kazunori Takahashi,Hidemasa Miura

doi:10.1063/5.0069184

Abstract

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.

Highlights

Various types of electric propulsion devices have been investigated and some of them have been successfully used in space missions as represented by gridded ion thrusters and Hall effect thrusters.1–3 Typically, the ions produced in the gaseous plasma sources are accelerated by applying electric fields and exhausted from the system; the electrons have to be simultaneously exhausted to maintain the charge neutrality and to prevent the spacecraft from being charged up
No detectable discharge current is observed for the initial ∼ 6 μs; it is found that the discharge current much larger than that in the DC magnetron sputtering (DCMS) appears after ∼ 6 μs and the effective discharge voltage decreases due to the presence of the resistor of 7.5 Ω
The thrusts imparted by the DC and high power impulse magnetron sputtering (DCMS and HiPIMS) are measured by attaching the magnetron source to the pendulum thrust balance installed in the vacuum chamber, where the averaged power is chosen as 50–150 W and the argon propellant is used to maintain the discharges

Summary

Introduction

Various types of electric propulsion devices have been investigated and some of them have been successfully used in space missions as represented by gridded ion thrusters and Hall effect thrusters.1–3 Typically, the ions produced in the gaseous plasma sources are accelerated by applying electric fields and exhausted from the system; the electrons have to be simultaneously exhausted to maintain the charge neutrality and to prevent the spacecraft from being charged up.

Results

Conclusion