Influence of background gas pressure on copper film deposition and ion current in a hot refractory anode vacuum ARC

It was shown that the film thickness was uniform with respect to the azimuthal angle around the electrode axis within approximately 10%. The film thickness was independent of gas pressure p, below a critical value pcr. For p > pcr, the film thickness decreased with p, eventually reaching 0. The value of pcr was less for gases with larger molecular weight-60, 10 and 5 mTorr (0.67, 1.33 and 8 Pa) for He, N2 and Ar, respectively. The ion current to a 78 mm2 probe in vacuo increased with time and reached a saturation value of approximately 4.5 mA after about 60 s from arc ignition. The ion flux fraction in the total deposition mass flux was estimated to be about 60% in the fully developed HRAVA (t = 60-90 s).