Apparatus for Extracting Low Energy Ion Beam

A workpiece processing apparatus, comprising:

• a plasma chamber having walls and an extraction plate with an extraction aperture;
• a ground electrode having a ground electrode aperture, having a fixed spatial relationship to the extraction plate;
• and
• a suppression electrode disposed between the ground electrode and the extraction plate;
• wherein the suppression electrode is affixed to one of the extraction plate and the ground electrode;
• such that a distance of a first gap between the extraction plate and the suppression electrode, and a distance of a second gap between the suppression electrode and the ground electrode are both fixed.

A workpiece processing apparatus, comprising:

• a plasma chamber having walls and an extraction plate with an extraction aperture;
• a ground electrode having a ground electrode aperture, physically connected to the extraction plate using ground electrode insulators;
• and
• a suppression electrode disposed between the ground electrode and the extraction plate;
• wherein the suppression electrode is movable relative to the extraction plate and the ground electrode.