Plasma processing apparatus and plasma processing method

Abstract

A plasma processing apparatus and method which includes a vacuum processing chamber, a plasma generating unit, a process gas supply unit, a specimen table, and a vacuum pumping unit. The specimen table includes an electrostatic arrangement for holding a specimen on a holding surface of the specimen table by electrostatic force, a specimen table cover arranged around the specimen table, and first and second heat transfer gas supply units. The first heat transfer gas supply unit has a main path for supplying a heat transfer gas to the specimen holding surface for cooling the specimen, and the second heat transfer gas supply unit has a branch path branched from the main path of the first heat transfer gas supply unit for supplying a part of the heat transfer gas to a gap between an outer portion of the specimen holding surface and the specimen table cover.

1 . A plasma processing apparatus including a vacuum processing chamber, a plasma generating unit, a process gas supply unit for supplying gas to the vacuum process chamber, a specimen table having a specimen holding surface for holding a specimen, and a vacuum pumping unit for evacuating the vacuum processing chamber; 
 wherein the specimen table comprises:    electrostatic means for holding the specimen on a holding surface of the specimen table by electrostatic force;    a specimen table cover arranged around the specimen table;    a first heat transfer gas supply unit having a main path for supplying a heat transfer gas to the specimen holding surface for cooling the specimen; and    a second heat transfer gas supply unit having a branch path branched from the main path of the first heat transfer gas supply unit for supplying a part of the heat transfer gas to a gap between an outer portion of the specimen holding surface and the specimen table cover.    
   
   
       2 . The plasma processing apparatus according to  claim 1 , comprising a gas sealing unit arranged between the outer portion of the specimen holding surface and the specimen table cover so as to form the gap.  
   
   
       3 . A plasma processing method for processing a specimen by a plasma processing apparatus including a vacuum process chamber, a plasma generating unit, a process gas supply unit for supplying gas to the vacuum process chamber, a specimen table including a specimen holding surface for holding a specimen, an electrostatic means for holding the specimen on the holding surface, and a specimen table cover arranged at an outer peripheral portion of the specimen holding surface for covering the specimen table; 
 wherein the processing method comprises the steps of:    holding the specimen on the holding surface of the specimen table by an electrostatic force generated by the electrostatic means;    supplying a heat transfer gas to the specimen holding surface for cooling the specimen through a main path of a first heat transfer gas supply unit; and    supplying a part of the heat transfer gas to a gap between the outer portion of the specimen holding surface and the specimen table cover through a branch path of a second heat transfer gas supply unit branched from the main path of the first heat transfer gas supply unit;    whereby temperature fluctuation of the specimen table cover during processing of the specimen is restrained.