A filtered cathodic-arc plasma source of lower plasma losses and higher output plasma current to input current efficiency is disclosed. Plasma filtering is accomplished in a right angle bend magnetic filter arranged to include the effects of at least three added magnetic coils located at the right angle bend of the filter path. These magnetic coils and other filter attributes, including an array of transverse fins and a magnetic cusp trap in the filter path, achieve desirable magnetic flux paths, lower plasma collision losses and reduced undesired particle output from the plasma filter. Multiple cathode sources, multiple plasma output ports, Larmour radius influence, equipotential magnetic flux lines and electron/ion interaction considerations are also included in the plasma source. Application of the plasma source to film coating processes is included.
An apparatus for generating plasma includes a cathode having an evaporable surface configured to emit a material comprising plasma and macroparticles; oppositely directed output apertures configured to direct the plasma; a filter configured to transmit at least some of the plasma to the output apertures while preventing transmission of at least some of the macroparticles, the filter comprising at least one deflection electrode disposed generally parallel to and facing at least a portion of the evaporable surface; a first element for generating a first magnetic field component having a first polarity between the cathode and the at least one deflection electrode; and a second element for generating a second magnetic field component having a second polarity at the evaporable surface of the cathode that is opposite that of the first polarity such that a low-field region is created between the evaporable surface and the at least one deflection electrode.
