Low profile magnetic filter

摘要

A plasma processing apparatus includes a processing chamber having a plasma processing space therein and a substrate support in the processing chamber at a first end for supporting a substrate. A plasma source is coupled into the processing space and configured to form a plasma at a second end of the processing chamber opposite said first end. The apparatus further includes a magnetic grid having an intensity of a magnetic flux therein, a plurality of passageways penetrating from a first side to a second side, a thickness, a transparency, a passageway aspect ratio, and a position within the processing chamber between the second end and the substrate. The intensity, the thickness, the transparency, the passageway aspect ratio, and the position are configured to cause electrons having energies above an acceptable maximum level to divert from the direction. A method of obtaining low average electron energy flux onto the substrate is also provided.

主权项

1. A method of obtaining a low average electron energy flux onto a substrate in a processing chamber, comprising:
supporting a substrate to be processed at a first end of a processing chamber with a surface of the substrate facing a processing space in the processing chamber that contains a processing gas; coupling energy into the processing space by a surface wave plasma (SWP) source that includes a radial line slot antenna (RLSA) disposed near a second end of the processing chamber opposite the substrate to form a surface wave plasma containing ions of the processing gas at the second end of the processing chamber; allowing electrons to propagate in a direction from the second end of the processing chamber toward the substrate at the first end of the processing chamber; providing a magnetic grid having a plurality of passageways, a thickness, a transparency, a passageway aspect ratio, and a position within the processing chamber between the second end and the substrate; establishing an intensity of a magnetic flux through the magnetic grid; and adjusting the intensity, the thickness, the transparency, the passageway aspect ratio, and the position to cause the electrons that are a top 20% most energetic of the electrons to divert from the direction to produce a concentration of electrons that are an 80% less energetic of the electrons near the substrate.