Plasma immersion ion milling apparatus and method

A plasma immersion ion milling apparatus, comprising:

• a vacuum chamber which is electrically insulated and in which plasma is distributed;
• a support on which a workpiece is placed and disposed in the vacuum chamber;
• a housing including a slot part disposed along a surface of a workpiece on at least one side thereof, being conductive, enclosing the workpiece to isolate the workpiece from plasma, electrically connected to the workpiece, and being rotary;
• a rotating element for rotating the housing;
• and
• a power source for supplying power to the workpiece and the housing,
• wherein a bias which is negative compared to a plasma potential is applied to the workpiece and the housing, the housing functions as an extracting electrode with the slot part and rotates, and ions accelerated within a sheath formed around the housing are extracted into a space between the housing and the workpiece through the extracting electrode and thus bombard the workpiece, thereby polishing the surface of the workpiece.

A plasma immersion ion milling method, comprising:

• disposing, in an electrically insulated vacuum chamber, a workpiece on a rotary support electrically insulated from the chamber;
• enclosing the workpiece with a housing which is electrically connected to the workpiece and functions as an ion extracting electrode with a slot part;
• forming plasma in the chamber;
• applying a negative bias to the workpiece and the housing and rotating the workpiece;
• and
• extracting ions, which were accelerated within a sheath formed around the housing, into a space between the housing and the workpiece through the extracting electrode so as to bombard the workpiece, thus polishing a surface of the workpiece.