Plasma processing apparatus

Abstract

A plasma processing apparatus includes a lower electrode 12 on which a wafer W is mounted. A second coolant path 70b is formed in a spiral shape in a region within the lower electrode 12 corresponding to a region where the wafer W is placed. Further, a first coolant path 70a is formed in a spiral shape to be located in a lower region within the lower electrode 12 corresponding to a region where the second coolant path 70b is formed. A pipeline 72 connected to a chiller unit 71 is branched into a first pipeline 72a connected to the first coolant path 70a and a second pipeline 72b connected to the second coolant path 70b. A check valve 90 allowing a coolant to flow in one direction is provided on the first pipeline 72a, and a reversing unit 92 reversing a flow direction of the coolant is provided on the pipeline 72.

We claim: 
     
         1 . A plasma processing apparatus, comprising:
 a processing chamber in which a plasma processing space is formed;   a mounting table provided within the processing chamber and configured to mount thereon a processing target substrate;   a gas supply device configured to introduce a processing gas to be used in plasma reaction into the plasma processing space;   a plasma generating device configured to supply electromagnetic energy to excite the processing gas introduced in the plasma processing space into plasma;   a plurality of coolant paths formed within the mounting table;   a temperature controller configured to control a temperature of a coolant flown and circulated through the plurality of coolant paths;   a check valve provided at a part of the plurality of coolant paths; and   a reversing unit configured to reverse a flow direction of the coolant that flows and circulates through the plurality of coolant paths,   wherein the plurality of coolant paths include a first coolant path and a second coolant path which are formed in a region within the mounting table corresponding to a region where the processing target substrate is placed, and the first coolant path and the second coolant path are arranged separately in a vertical direction.   
     
     
         2 . The plasma processing apparatus of  claim 1 , further comprising:
 a controller configured to control the reversing unit to reverse the flow direction of the coolant according to a switchover timing of plasma processes performed in the plasma processing apparatus.   
     
     
         3 . The plasma processing apparatus of  claim 1 ,
 wherein the first coolant path is formed in a spiral shape in a lower region within the mounting table, and   the second coolant path is formed in a spiral shape in an upper region within the mounting table.   
     
     
         4 . The plasma processing apparatus of  claim 1 , further comprising:
 a chiller unit pipeline positioned between the temperature controller and the first and second coolant paths,   an intermediate pipeline positioned between the temperature controller and the reversing unit, and   a reversing unit pipeline positioned between the reversing unit and the first and second coolant paths.   
     
     
         5 . The plasma processing apparatus of  claim 4 ,
 wherein the chiller unit pipeline is branched into two first pipelines and the two first pipelines are directly connected with the chiller unit pipeline,   the reversing unit pipeline is branched into two second pipelines and the two second pipelines are directly connected with the reversing unit pipeline,   one of the first pipelines and one of the second pipelines are connected with the first coolant path at different circumferential positions,   the other one of the first pipelines and the other one of the second pipelines are connected with the second coolant path at different circumferential positions.   
     
     
         6 . The plasma processing apparatus of  claim 5 ,
 wherein the check valve is provided at the one of the first pipelines.   
     
     
         7 . The plasma processing apparatus of  claim 6 ,
 wherein the check valve includes a valve sheet and a plate-shaped valve body provided at the valve sheet,   when the coolant flows in one direction, the plate-shaped valve body of the check valve is configured to stand up by a force of the coolant, so that the one of the first pipelines is closed, and   when the coolant flows in an opposite direction, the plate-shaped valve body of the check valve is configured to fall down by the force of the coolant, so that the one of the first pipelines is opened.