Paired dynamic parallel plate capacitively coupled plasmas
Processing chambers with a plurality of processing stations and individual wafer support surfaces are described. The processing stations and wafer support surfaces are arranged so that there is an equal number of processing stations and heaters. An RF generator is connected to a first electrode in a first station and a second electrode in a second station. A bottom RF path is formed by a connection between a first support surface and a second support surface.
1. A method of processing a plurality of substrates, the method comprising:
powering an RF source connected to a first electrode in a first plasma processing station and a second electrode in a second plasma processing station to form a top RF path, the first plasma processing station comprising a first support surface and the second plasma processing station comprising a second support surface, a connection between the first support surface and the second support surfaces forming a bottom RF path, wherein current flows in one direction from the RF source to the first electrode, to the first support surface, through the connection between the first support surface and the second support surface to the second support surface and then back to the RF source.
2. The method of claim 1 , wherein the connection between the support surfaces is within a wafer pedestal.
3. The method of claim 1 , wherein the connection between the support surfaces comprises a coaxial connection.
4. The method of claim 3 , further comprising a second bottom RF path connecting the support surfaces.
5. The method of claim 3 , wherein the top RF path is formed with a coaxial cable.
6. The method of claim 3 , further comprising adjusting a tuning element connected to each of the support surfaces.
7. The method of claim 6 , wherein the tuning element comprises a balun.
8. The method of claim 6 , wherein adjusting the tuning element reduces voltage difference between the support surfaces and a surrounding metal structure forming a processing chamber.
9. The method of claim 3 , further comprising a dielectric spacer separating the support surfaces.
10. The method of claim 9 , wherein the dielectric spacer comprises one or more of quartz, ceramic or polytetrafluoroethylene.
11. The method of claim 6 , wherein the bottom RF path is formed without a coaxial cable.
12. A method of processing a plurality of substrates, the method comprising: powering an RF source connected to a first electrode in a first plasma processing station and a second electrode in a second plasma processing station to form a top RF path, the first plasma processing station and second plasma processing station arranged around an interior of a processing chamber comprising a plurality of processing stations, a wafer pedestal having a plurality of heaters to support individual wafers for processing, the number of heaters equal to the number of processing stations, the plurality of heaters comprising a first heater and a second heater, the first heater adjacent to and spaced from the first electrode and the second heater adjacent to and spaced from the second electrode, a connection is between the first heater and the second heater of the wafer pedestal to form a bottom RF path, wherein current flows in one direction from the RF source to the first electrode, to the first heater, through the connection between the first heater and the second heater to the second heater and then back to the RF source.
13. The method of claim 12 , wherein the connection between the first heater and second heater is within the wafer pedestal.
14. The method of claim 12 , wherein the connection between the first heater and the second heater comprises a coaxial connection.
15. The method of claim 14 , further comprising a second bottom RF path connecting the first heater to the second heater.
16. The method of claim 14 , further comprising adjusting a tuning element connected to each of the first heater and second heater.
17. The method of claim 14 , further comprising a dielectric spacer separating the first heater from the second heater.