Two piece electrode assembly with gap for plasma control

An apparatus for distributing plasma products, comprising:

• a first electrode, comprising a first planar surface and a second planar surface separated by a first electrode thickness that is between 0.100 inch and 1.000 inch, wherein the first electrode forms a plurality of first apertures extending therethrough, from the first planar surface to the second planar surface;
• and
• a second electrode, comprising a third planar surface and a fourth planar surface separated by a second electrode thickness that is between 0.100 inch and 1.000 inch, wherein the second electrode forms a plurality of second apertures extending therethrough, from the third planar surface to the fourth planar surface;
• wherein:
• the second electrode is coupled fixedly with the first electrode such that the third planar surface is disposed adjacent to the second planar surface, with a gap distance of 0.005 inches to 0.050 inches therebetween;
• and
• the first and second apertures are arranged within the first and second electrodes such that none of the first apertures aligns with any of the second apertures to form an open straight-line path extending through both the first and second electrodes.

A plasma source, comprising:

• a plasma generation region configured for introduction of one or more source gases therein;
• an RF power supply that provides electromagnetic power to the one or more source gases to ignite a plasma within the plasma generation region;
• a two piece electrode assembly that bounds the plasma generation region on one side, the two piece electrode assembly comprising:
• a first electrode that defines a first planar surface and a second planar surface, wherein:
• the first planar surface and the second planar surface are separated by a first electrode thickness that is between 0.100 inch and 1.000 inch, and
• the first electrode forms a plurality of first apertures extending therethrough, from the first planar surface to the second planar surface;
• and
• a second electrode that defines a third planar surface and a fourth planar surface, wherein:
• the third planar surface and the fourth planar surface separated by a second electrode thickness that is between 0.100 inch and 1.000 inch,
• the second electrode forms a plurality of second apertures extending therethrough, from the third planar surface to the fourth planar surface,
• the second electrode is coupled with the first electrode on the one side of the plasma generation region, such that the third planar surface is disposed adjacent to the second planar surface;
• and
• the first electrode and the second electrode are fixed or positionable with respect to one another so as to provide:
• a gap between the first electrode and the second electrode, the gap forming a gap distance of 0.005 inches to 0.050 inches between the second planar surface and the third planar surface, and
• a lateral separation of any point within one of the first apertures, with respect to any point within any of the second apertures, of greater than three times the gap distance;
• and
• the plasma source further comprising a second region that is bounded on at least one side by the fourth planar surface of the second electrode, wherein the gap and the lateral separation cooperate to substantially reduce transmission of free electrons and ionized species from the plasma generation region to the second region.