Method and apparatus for valve deposition cleaning and prevention by plasma discharge
A valve assembly is provided that comprises a vacuum valve including a body and an electrically grounded surface on at least a surface of the body and an electrode extending substantially parallel to the electrically grounded surface and adjacent to the vacuum valve. The vacuum valve assembly also includes a barrier dielectric, a least a portion of which is located between the electrode and the electrically grounded surface. The vacuum valve assembly further includes a dielectric barrier discharge structure formed from the electrically grounded surface, the electrode, and the barrier dielectric. The dielectric barrier discharge structure is adapted to generate a plasma on the electrically grounded surface to clean at least a portion of the vacuum valve.
1. A valve assembly comprising:
a vacuum valve including an electrically grounded surface;
an electrode adjacent to the electrically grounded surface of the vacuum valve;
a barrier dielectric, at least a portion of which is located between the electrode and the electrically grounded surface; and
a dielectric barrier discharge structure formed from the electrically grounded surface, the electrode, and the barrier dielectric, wherein the dielectric barrier discharge structure is adapted to generate a plasma in a gap between the barrier dielectric and the electrically grounded surface to process at least a portion of the vacuum valve, and wherein the electrically grounded surface of the vacuum valve forms a grounded electrode for generating the plasma.
2. The valve assembly of claim 1 , further comprising a buried electrode assembly including the electrode, the barrier dielectric and an isolator dielectric.
3. The valve assembly of claim 2 , wherein a body of the vacuum valve is cylindrical and the buried electrode assembly is cylindrical, wherein a circular opening in the body and a circular opening in the buried electrode assembly are concentrically aligned along a longitudinal axis.
4. The valve assembly of claim 1 , wherein the electrode is formed on an interior surface of the barrier dielectric.
5. The valve assembly of claim 2 , further comprising an extension portion coupled to a body of the vacuum valve for securing the buried electrode assembly against the vacuum valve.
6. The valve assembly of claim 1 , wherein the vacuum valve comprises at least one of a throttle valve, isolation valve or pendulum valve.
7. The valve assembly of claim 1 , wherein the electrode or the electrically grounded surface includes at least a portion of a control element of the vacuum valve.
8. The valve assembly of claim 1 , wherein the vacuum valve, the electrode and the barrier dielectric comprise a unitary structure.
9. The valve assembly of claim 1 , wherein each of the vacuum valve or the electrode is a replaceable consumable.
10. The valve assembly of claim 1 , wherein the barrier dielectric comprises at least one of quartz, alumina, glass or polymide.
11. The valve assembly of claim 1 , further comprising a power supply connected between the electrode and the electrically grounded surface for generating the plasma.
12. A method comprising:
providing a vacuum valve including a body and a control element;
electrically grounding a surface of at least one of the body or the control element to form an electrically grounded surface;
locating an electrode adjacent to the electrically grounded surface of the vacuum valve;
inserting at least a portion of a barrier dielectric between the electrode and the electrically grounded surface of the vacuum valve; and
creating a dielectric barrier discharge structure using the electrode, the barrier dielectric, and the electrically grounded surface, wherein the dielectric barrier discharge structure is adapted to generate a localized plasma coupled to the vacuum valve for processing at least a portion of the vacuum valve, and wherein the electrically grounded surface of the vacuum valve forms a grounded electrode for generating the plasma in a gap between the barrier dielectric and the electrically grounded surface.
13. The method of claim 12 , further comprising locating the electrode on an interior surface of the barrier dielectric.
14. The method of claim 12 , further comprising securing the electrode and the barrier dielectric against the body of the vacuum valve.
15. The method of claim 12 , further comprising providing a high voltage alternative current (AC) between the electrode and the electrically grounded surface to generate the localized plasma.
16. The method of claim 12 , wherein a power of the localized plasma is about 15 Watts at about 2 Torr.
17. The method of claim 12 , further comprising locating the vacuum valve and the dielectric barrier discharge structure downstream from a wafer processing chamber.
18. The method of claim 17 , further comprising using the localized plasma to clean the at least a portion of the vacuum valve in at least one of a prevention mode during an operation of the wafer processing chamber or an elimination mode after an operation of the wafer processing chamber.
19. The method of claim 18 , wherein the prevention mode comprises:
generating a primary plasma in the wafer processing chamber in connection with performance of a wafer deposition process within the wafer processing chamber;
generating, in connection with the wafer deposition process within the wafer processing chamber, a gaseous byproduct that flows from the wafer processing chamber to the vacuum valve; and
generating the localized plasma coupled to the vacuum valve, during the performance of the wafer deposition process within the wafer processing chamber, to prevent condensation of the gaseous byproduct to solid deposits on the vacuum valve.
20. The method of claim 18 , wherein the elimination mode comprises:
generating a primary plasma in the wafer processing chamber in connection with execution of a wafer deposition process within the wafer processing chamber;
generating, in connection with the wafer deposition process within the wafer processing chamber, solid deposits on the vacuum valve; and
generating the localized plasma coupled to the vacuum valve, after the execution of the wafer deposition process, to substantially etch away the solid deposits on the vacuum valve.
21. The method of claim 20 , further comprising supplying a cleaning gas to the vacuum valve prior to generating the localized plasma.
22. The method of claim 18 , further comprising using the localized plasma to clean at least a portion of a roughing line adjacent to the vacuum valve.