Patent ID: 7632375

Claim:
A vacuum plasma processor comprising a processing chamber having a wall at a reference potential and an outlet port, a region in the chamber spaced from the wall and outlet port in which a plasma is adapted to be excited, a structure in the chamber for substantially confining the plasma to the region, an inlet of the chamber for enabling gas that forms the plasma to flow from a gas source into the region, the structure being arranged for converting the gas that flows into the region via the inlet into the plasma, the structure including a gap in the structure for enabling gas to flow from the region to the outlet port, and an AC electric power source having differing terminals respectively connected to differing spaced electric conductors on the structure for causing an AC electric field for confining the plasma to subsist in the gap and between the conductors, the electric field causing greater confining of the plasma to the region than is attained without electrically coupling power from the source to the conductors on the plasma confining structure.