Electrode systems and methods of using electrodes
An electrode assembly comprises a coil of electrode material surrounded by a shield having one or more outlets and a supply of shielding gas directed along an axis X-X of said coil before exiting from said shield.
1. An electrode for a deposition process comprising:
an electrode material;
a gas inlet positioned relative to said electrode material for directing a shielding gas over an outer surface of said electrode material; and
a base, said base including a gas inlet opening and one or more gas outlet openings positioned for directing gas towards and around said electrode material;
wherein the electrode material comprises a metal coil having a longitudinal central axis and wherein said gas inlet is positioned for releasing said gas so as to flow within said metal coil substantially along said axis.
2. An electrode as claimed in claim 1 further comprising a shield encasing said electrode material, said shield including a surface and an outlet within said surface through which, in operation, said shielding gas may pass.
3. An electrode as claimed in claim 1 further comprising a shield encasing said electrode material, said shield including a surface and an outlet and in which said shield comprises a tube having a sidewall, said sidewalls having a plurality of outlets.
4. An electrode as claimed in claim 1 further comprising a shield encasing said electrode material, said shield including a surface and an outlet and in which said axis comprises an arc.
5. An electrode as claimed in claim 1 further comprising a shield encasing said electrode material, said shield including a surface and an outlet and in which said axis extends through a complete circle.
6. An electrode as claimed in claim 1 further comprising a shield encasing said electrode material, said shield including a surface and an outlet and in which said shield has a plurality of said outlets and wherein the distance between said outlets reduces as the distance from the gas inlet increases.
7. An electrode as claimed in claim 1 further comprising a shield encasing said electrode material, said shield including a surface and a plurality of outlets, in which the diameter of said outlets increases as the distance from the gas inlet increases.
8. An electrode as claimed in claim 1 further comprising a shield encasing said electrode material, said shield including a surface and a plurality of outlets and in which the outlets include central axes and said axes converge.
9. An electrode as claimed in claim 1 wherein said electrode material comprises a refractory metal.
10. An electrode as claimed in claim 1 wherein said electrode material is selected from a list comprising:
tantalum, tungsten and/or molybdenum.
11. An electrode as claimed in claim 1 further comprising a shield encasing said electrode material and having a plurality of outlets along the length of said shield and around the circumference thereof.
12. An electrode as claimed in claim 1 further comprising a shield encasing said electrode material and having an outlet at a point remote from the gas inlet, thereby to cause gas to pass along said electrode material before exiting from said shield.
13. An electrode as claimed in claim 1 further comprising a non-metallic shield encasing said electrode material.
14. An electrode as claimed in claim 1 further comprising a shield of transparent material.
15. An electrode as claimed in claim 1 further comprising a shield of quartz.
16. An electrode as claimed in claim 1 wherein said base includes a plenum chamber between said inlet opening and said one or more outlet openings.
17. An electrode as claimed in claim 1 wherein said base includes an external coupling for coupling to an aperture in a wall of a processing chamber.
18. An electrode as claimed in claim 1 wherein said coil comprises an open coil.
19. An electrode as claimed in claim 1 wherein said coil comprises an end portion for electrical connection to a mounting portion.
20. An electrode as claimed in claim 1 further comprising an electrode mounting portion wherein said mounting portion is within said base and has an external electrical connector for connection to an external supply of electricity.
21. An electrode as claimed in claim 1 wherein said electrode material comprises a tungsten filament.
22. An electrode as claimed in claim 21 wherein said filament comprises a tungsten filament of 0.2 mm diameter.
23. An electrode as claimed in claim 1 further comprising a source of pulsed electrical supply for supplying a pulsed current to said electrode.
24. An electrode for a deposition process comprising:
an electrode material;
a gas inlet positioned relative to said electrode material for directing a shielding gas over an outer surface of said electrode material; and
a shield encasing said electrode material, said shield including a surface and an outlet and in which said shield comprises a tube having a sidewall, said sidewall having a plurality of outlets;
wherein the electrode material comprises a metal coil having a longitudinal central axis and wherein said gas inlet is positioned for releasing said gas so as to flow within said metal coil substantially along said axis.
25. An electrode for a deposition process comprising:
an electrode material;
a gas inlet positioned relative to said electrode material for directing a shielding gas over an outer surface of said electrode material; and
a base portion and a shield around said electrode material, wherein a seal is between said base portion and said shield;
wherein the electrode material comprises a metal coil having a longitudinal central axis and wherein said gas inlet is positioned for releasing said gas so as to flow within said metal coil substantially along said axis.
26. An electrode for a deposition process in which deposition is from a treatment gas comprising:
an electrode material;
a gas inlet positioned relative to said electrode material for directing a shielding gas over an outer surface of said electrode material; and
a non-metallic shield encasing said electrode material to shield said electrode material from exposure to said treatment gas, said shield including a sidewall having at least one outlet;
wherein the electrode material comprises a metal coil having a longitudinal central axis and wherein said gas inlet is positioned for releasing said shielding gas so as to flow within said metal coil substantially along said axis.