Shielding for cathodic arc metal ion sources

Abstract

The invention provides a shielding device for a cathode arc metal ion source. The cathode arc metal ion source comprises a target material, a magnetic field assembly located below the target material and producing a magnetic field above the target material, and an ion source hermetically connected with the target material to enclose the magnetic field assembly; the shielding device comprises marginal shielding pieces arranged around but spaced from the margin of the target material and a central shielding piece located above the center of the target material and positioned at the center relative to the marginal shielding pieces. Application of the central shielding piece and the marginal shielding pieces provided in the invention and an arc closed magnetic field constructed on the surface of a cathode target material by using a magnetic circuit makes cathode spots only do unilateral zigzag movement along a rectangular annular runway, and therefore, nonuniformity of deposition caused by random reciprocation of arc spots at halfway can be avoided.

Description

technical field [0001] The invention relates to a cathode arc metal ion source, in particular to a shielding device for the cathode arc metal ion source. Background technique [0002] Using a vacuum cathode arc ion source is one of the main methods to generate metal ions. It can evaporate and ionize the cathode target in a vacuum environment to form plasma. The ionization rate of the evaporated target is greater than 80%. A negative voltage is applied to the cathode target of the cathode arc ion source, and the arc discharge on the surface of the target is excited by the arc striking device to form the cathode arc spot. The area is very small (<1mm 2 ) in the cathode arc spot, the locally applied power is very large (3KW), so that a local high temperature (>6000°C) is formed at the cathode arc spot, and the cathode material is evaporated and ionized into metal ions, which meet the surface of the workpiece in vacuum Condensation occurs to form a thin film or coating. ...

AI Technical Summary

Problems solved by technology

When the magnetic field decreases, the swing width of the arc spot increases, and the utilization rate of the target material increases, but it is possible that the arc spot enters the opposite runway at a certain position in the middle, turns back at a certain position of the circular runway, and does not completely close the runway The discharge causes the ion beam current to be strong in the middle and weak at both ends, reducing the uniformity of deposition

For this reason, there are patents using electromagnetic scanning magnetic field technology to improve the above phenomenon, but it has not been completely resolved.

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