Plasma Processing Apparatus And Plasma Processing Method

A plasma processing method for processing a specimen by a plasma processing apparatus including a vacuum process chamber, a plasma generating unit for generating a plasma in the vacuum processing chamber, a process gas supply unit for supplying gas to the vacuum process chamber, a metallic specimen table including a specimen holding surface for holding a specimen to be processed, an electrostatic means for holding the specimen on the holding surface, and a specimen table cover arranged in an upper portion of the metallic specimen table on an outer portion of the specimen holding surface so as to cover at least a part of an upper surface of the metallic specimen table disposed at a position facing and below the specimen;

• wherein the processing method comprises the steps of:
• holding the specimen on the holding surface of the metallic specimen table by an electrostatic force generated by the electrostatic means;
• supplying a heat transfer gas between the specimen holding surface and the specimen for cooling the specimen through a main path inside of the metallic specimen table of a first heat transfer gas supply unit;
• and
• supplying a part of the heat transfer gas from the main path directly to a closed gap between the outer portion of the specimen holding surface and the specimen table cover through a branch path inside of the metallic specimen table of a second heat transfer gas supply unit and branched from the main path inside of the metallic specimen table of the first heat transfer gas supply unit;
• whereby temperature fluctuation of the specimen table cover during processing of the specimen is restrained and discharge of undesired metals is prevented when the metallic specimen table is exposed to the plasma.