| 摘要 |
The invention provides an arc coating apparatus having a steering magnetic field source comprising a plurality of electrically independent closed-loop steering conductors disposed in the vicinity of the target surface, each steering conductor being controlled independently of the other steering conductors. Increasing the current through one steering conductor increases the strength of the magnetic field generated by that conductor relative to the steering conductor along the opposite side of the cathode plate, shifting the magnetic field on the opposite side of th e cathode plate transversely. Selective unbalancing of the steering conductor currents thus increases the effective breadth of the erosion zone to provide more uniform erosion of the target surface. The steering conductors may be disposed in front of or behind the target surface of the cathode plate. In a further embodiment, groups of steering conductors are disposed along opposite sides of the cathode plate. By selectively applying a current through one conductor in each group, the path of the arc spot shifts to an erosion corridor defined by the active steering conductor. The inventi on also provides a plurality of internal anodes disposed within the plasma duct, for deflecting the plasma flow and preserving a high ionization levelof the plasma. The invention also provides a magnetic focusing system which confines the flow of plasma between magnetic fields generated on opposite sides of the coating chamber. The plas ma focusing system can be used to deflect the plasma flow off of the working ax is of the cathode, to remove the neutral component of the plasma which otherwise constitutes a contaminant, by disposing the plasma focusing coils in progressively asymmetric relation to the working axis of the cathode, to deflect the flow of plasma along a curvate path toward a substrate holder. The invention also provides a shield at floating potential, restricting the cathode spot from migrating into selecte d regions of the target evaporation surface outside of the desired erosion zone. The shie ld may be positioned immediately above the region of the target surface in the vicinit y of the anode, protecting the anode from deposition of cathodic evaporate and providing better distribution of cathodic evaporate over the substrates to be coated.< /SDOAB>
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