Patent ID: 8835869

Claim:
An ion source for a plasma processing apparatus, comprising: a plasma discharge chamber configured to contain an ignited plasma therein; an optical grid positioned proximate a first end of the plasma discharge chamber, the optical grid having a plurality of apertures configured such that ions from the plasma within the plasma discharge chamber pass through the apertures of the plurality and bombard a substrate; a re-entrant vessel positioned proximate to a second end of the plasma discharge chamber, the second end generally opposing the first end, the re-entrant chamber configured to shape the plasma within the plasma discharge chamber; and a plasma shaper extending from the re-entrant vessel and into the plasma discharge chamber, wherein a position of the plasma shaper relative to the optical grid is adjustable between a first position and a second position that is closer to the optical grid than the first position, the position of the plasma shaper being operable to change a plasma density distribution within the plasma discharge chamber.