Hollow cathode discharge source of metal vapor
AssigneeThe United States of America as represented by the Secretary of the Army
InventorsWilliam F. Henshaw, John R. White, Andrus Niiler
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Abstract
A hollow cathode discharge device is disclosed for ion plating a substrate with high temperature metal vapor. A hollow cathode tube is adapted to receive pellets of the high temperature metal at a short location from the cathode tube opening which is selected to correspond to a temperature peak along the length of the cathode tube. The temperature peak is a characteristic of the cathode diameter and gas flow rate in the tube. Inert gas is supplied to the tube and, the tube may be shielded and provided with a constriction at its end opening. An anode is spaced from the cathode tube opening and power supply is provided for supplying a negative bias to the cathode tube and a positive bias to the anode.
Claims8
A device for ion plating a substrate with high temperature metal vapor comprising:
- an evacuable chamber enclosing;
- a hollow cathode tube having an end opening and adapted to receive a high temperature plating metal at a selected distance from said opening;
- gas supply means connected to said cathode tube for supplying a gas therethrough at a selected flow rate;
- an anode spaced from said cathode tube open end;
- and
- power supply means connected to said cathode tube and anode to bias said cathode tube negatively with respect to said anode sufficiently to produce an arc therebetween and evaporate the high temperature metal in said cathode tube;
- means for mounting a hollow substrate surrounding said cathode and anode;
- and power supply means for negatively biassing said substrate;
- wherein said selected distance is chosen to correspond substantially to a location of maximum temperature which is a characteristic of the inside diameter of said cathode tube and the gas flow rate supplied by said gas supply means.
Dependencies are inferred from the claim text.