Optimal duct bias for transport of cathodic-arc plasmas

Carbon and titanium plasmas are used to investigate the effects of duct bias on the plasma transport through the magnetic duct of a cathodic-arc plasma source as a function of the magnetic-field strength and arc current so as to determine the optimal duct bias, at which the magnetic duct produces the maximum efficiency for plasma transport. The influence of the guiding magnetic field and arc current on the optimal duct bias is investigated. The optimal duct bias increases with the plasma density for carbon plasma, while the relationship is the opposite for the titanium plasma. The carbon-plasma behavior can be explained by a plasma-diffusion model presented in this paper, since the electron-ion collision frequency /spl nu//sub ei/ is less than the electron-cyclotron frequency /spl nu//sub c,e/. On the other hand, in a titanium plasma, /spl nu//sub ei/ is larger than /spl nu//sub c,e/, so this model is inaccurate. Our result shows that different kinds of plasmas have different transport behavior through the magnetic duct and thus, the duct parameters must be carefully chosen in order to achieve the optimal transport efficiency.

[1]  P. Chu,et al.  Wall sheath and optimal bias in magnetic filters for vacuum arc plasma sources , 2002 .

[2]  P. Chu,et al.  Dynamic mixing deposition of niobium nitride films by cathodic arc plasma in ambient nitrogen , 2001 .

[3]  P. Chu,et al.  Mechanism of enhanced plasma transport of vacuum arc plasma through curved magnetic ducts , 1999 .

[4]  M. Bilek,et al.  Deposition probe technique for the determination of film thickness uniformity , 1998 .

[5]  E. Oks,et al.  Ion charge state distributions of pulsed vacuum arc plasmas in strong magnetic fields , 1998 .

[6]  Ian G. Brown,et al.  CATHODIC ARC DEPOSITION OF FILMS , 1998 .

[7]  D. Mckenzie,et al.  Interactions of the directed plasma from a cathodic arc with electrodes and magnetic fields , 1996 .

[8]  E. Oks,et al.  Ion charge state distributions in high current vacuum arc plasmas in a magnetic field , 1996 .

[9]  S. Goldsmith,et al.  Ion current distribution in a filtered vacuum arc deposition system , 1995 .

[10]  Ian G. Brown,et al.  Some observations of the effect of magnetic field and arc current on the vacuum arc ion charge state distribution , 1995 .

[11]  A. Anders,et al.  Transport of vacuum arc plasmas through magnetic macroparticle filters , 1995 .

[12]  I. Brown.  Vacuum Arc Ion Sources , 1994, 1404.0514.

[13]  G. Amaratunga,et al.  Plasma motion in a filtered cathodic vacuum arc , 1993 .

[14]  J. Musil,et al.  Cathodic arc evaporation in thin film technology , 1992 .

[15]  S. Goldsmith,et al.  Principles and applications of vacuum arc coatings , 1989 .