Investigation of parameters of plasma generated by high-power impulse magnetron sputtering (HiPIMS) of graphite

摘要

High-power impulse magnetron sputtering (HiPIMS) of graphite is used for deposition of hard and wear-resistant amorphous carbon films, because tetragonal diamond-like carbon (DLC) bonds produced under subplantation mechanism at negative substrate bias voltage more intensive in the case of high-density plasma. In scientific literature one can find the fact that DLC films are more hard (37 GPa) in the case of short (7 μs) magnetron discharge pulses comparing to long (50 μs) ones (17 GPa) in HiPIMS of graphite. Likely, it is connected with denser plasma and more effective carbon subplantation in the case of short discharge pulses compared to long ones. To confirm this, it is necessary to investigate dependencies of plasma parameters (ion concentration, electron temperature, plasma and floating potentials) generated by HiPIMS of graphite on discharge pulse width. It was shown that electron temperature increased from 5.34 to 10.27 eV, and plasma density increased from 1.2?10SUP10/SUP to 2.2?10SUP10/SUP cmSUP?3/SUP while pulse width decreased from 100 to 15 μs. It can be explained by increase of plasma disequilibrium since pulse current and power density increased to 250 A and 39.4 W/cmSUP2/SUP, respectively.