Title :
Superposition of two plasma beams produced in a vacuum arc deposition apparatus
Author :
Zhitomirsky, Vladimir N. ; Boxman, Raymond L. ; Goldsmith, Samuel ; Grimberg, Ilana ; Weiss, Ben-Zion
Author_Institution :
Interdisciplinary Studies, Tel Aviv Univ., Israel
fDate :
8/1/1999 12:00:00 AM
Abstract :
Two plasma beams of different materials were produced from Ti, Zr, or Nb cathodes in a triple-cathode vacuum arc deposition apparatus. The cathodes were arranged in a circle centered on the system axis. The plasma produced by the cathode spots was transported through a straight plasma duct with an axial magnetic field, into a sample chamber, in which a single Langmuir probe, an array of probes, or a substrate could be mounted 560 mm from the cathode plane. The saturation ion current produced by one cathode, or by the simultaneous operation of two different cathodes, was measured in vacuum and in a 0.13-2.7 Pa nitrogen background. The spatial distribution of the composition of coatings deposited during simultaneous operation of different cathodes in nitrogen was also studied. It was shown that the ion current produced by each single cathode decreased by a factor of 20-100, and by a factor of ten during simultaneous operation of two cathodes, when the nitrogen pressure was increased from vacuum to P=2.7 Pa. During simultaneous operation of two cathodes, the ion saturation current was less than the sum of the ion currents produced by each cathode individually when P<0.4 Pa, while the simultaneous ion current was larger than the sum of the individual ion currents when P⩾0.4 Pa
Keywords :
Langmuir probes; cathodes; current density; current distribution; plasma density; plasma deposited coatings; plasma deposition; plasma jets; plasma production; plasma transport processes; vacuum arcs; 0.13 to 2.7 Pa; 0.4 Pa; Nb; Nb cathodes; Ti; Ti cathodes; Zr; Zr cathodes; axial magnetic field; cathode spots; ion current; ion currents; ion saturation current; plasma beams; plasma beams superposition; probe arrays; sample chamber; saturation ion current; single Langmuir probe; single cathode; spatial distribution; straight plasma duct; vacuum arc deposition apparatus; Cathodes; Magnetic field measurement; Magnetic materials; Nitrogen; Particle beams; Plasma materials processing; Plasma transport processes; Probes; Vacuum arcs; Zirconium;
Journal_Title :
Plasma Science, IEEE Transactions on