Plasma processing apparatus

Abstract

Provided is a plasma processing apparatus in which accuracy or reliability of processing is improved. This plasma processing apparatus includes a sample stage in a processing chamber arranged in a vacuum vessel and in which plasma is generated. The sample stage has a cylindrical shape and operates as an evaporator through which a refrigerant of a refrigerating cycle flows. Further, the apparatus includes refrigerant passages which are concentrically arranged inside of the sample stage, one or more detectors which detect vibrations of the sample stage, and an control unit which controls a temperature of the refrigerant flowing into the sample stage based on detection results of a dryness of the refrigerant flowing through the passages obtained from an output of the detectors.

1 . A plasma processing apparatus comprising:
 a processing chamber which is arranged in a vacuum vessel and in which plasma is generated;   a sample stage which is arranged inside toward the bottom of said processing chamber, of which a sample is mounted on an upper surface, which has a shape of a cylinder, and which operates as an evaporator by flowing a refrigerant of a refrigerating cycle through therein;   a refrigerant passage which is arranged in said sample stage and concentrically at a center of said cylinder;   one or more of detectors which are arranged under said sample stage and detect vibrations of said sample stage; and   an control unit which controls an operation of a compressor or an expansion valve configuring said refrigerating cycle based on a detection result of a dryness of said refrigerant flowing through said passage obtained from an output from said detector.   
     
     
         2 . The plasma processing apparatus according to  claim 1 ,
 wherein one or more of said detectors are arranged on a bottom surface of said sample stage and are connected to a position near an inlet of said refrigerant to inside of said sample stage.   
     
     
         3 . The plasma processing apparatus according to  claim 2 ,
 wherein additional one or more of said detectors are arranged on a bottom surface of said sample stage and are connected to a position near an outlet of said refrigerant from said sample stage.   
     
     
         4 . The plasma processing apparatus according to  claim 2 ,
 wherein said refrigerant passage comprises   a plurality of passages of shapes of circular arcs which are concentrically arranged in a multiple manner at different radial distances from said center in said sample stage; and   a connection passage connecting two passages among said passages of shapes of circular arcs, and   wherein additional one or more of said detectors are arranged on the bottom surface of said sample stage and near said connection passage.   
     
     
         5 . The plasma processing apparatus according to  claim 4 ,
 wherein plan-view shape of said connection passage has a curvature radius smaller than plan-view shape of said passages of shapes of circular arcs.   
     
     
         6 . The plasma processing apparatus according to  claim 4 ,
 wherein said passage in said sample stage is configured by joining two upper and lower members, and a defect in the junction of said upper and lower members is detected from an output from said one or more detectors arranged to be connected to a position near said connection passage on the bottom surface of said sample stage.   
     
     
         7 . The plasma processing apparatus according to  claim 1 , further comprising a member having electrical insulation arranged to be contacted with the bottom surface of said sample stage,
 wherein said one or more detectors are arranged to be contacted with said member having the insulation.   
     
     
         8 . A plasma processing apparatus comprising:
 a processing chamber which is arranged in a vacuum vessel and in which plasma is generated;   a sample stage which is arranged inside toward the bottom of said processing chamber, of which a sample is mounted on an upper surface, which has a shape of a cylinder, and which operates as an evaporator by flowing a refrigerant of a refrigerating cycle through therein;   a refrigerant passage which is arranged in said sample stage and concentrically at a center of said cylinder;   one or more of detectors which are arranged under said sample stage and detect vibrations of said sample stage; and   a control unit which is arranged between a compressor on said refrigerating cycle and said sample stage and controls a temperature of said refrigerant flowing into said sample stage based on a detection result of a dryness of said refrigerant flowing through said passage obtained from an output from said detector.