Plasma processing apparatus

Abstract

In a plasma processing apparatus that executes plasma processing on a semiconductor wafer placed inside a processing chamber by generating plasma with a processing gas supplied through a gas supply hole at an upper electrode (shower head) disposed inside the processing chamber, an interchangeable insert member is inserted at a gas passing hole at a gas supply unit to prevent entry of charged particles in the plasma generated in the processing chamber into the gas supply unit. This structure makes it possible to fully prevent the entry of charged particles in the plasma generated inside the processing chamber into the gas supply unit.

What is claimed is:  
     
         1 . A plasma processing apparatus that executes plasma processing on a workpiece placed inside a processing chamber by generating plasma with a processing gas supplied through a gas supply hole at a gas supply unit disposed within said processing chamber, wherein: 
 an interchangeable insert member that prevents entry of charged particles in the plasma generated inside said processing chamber into said gas supply unit is mounted at said gas supply hole in said gas supply unit.    
     
     
         2 . A plasma processing apparatus according to  claim 1 , wherein: 
 said insert member comprises a gas passage formed therein that communicates between an entry side and an exit side of said gas supply hole; and    said gas passage comprises a passage that regulates the flow along a central axis of said gas supply hole and extends perpendicular to or at an angle to the central axis.    
     
     
         3 . A plasma processing apparatus according to  claim 1 , wherein: 
 said insert member comprises a gas passage formed therein that communicates between an entry side and an exit side of said gas supply hole while regulating the flow along a central axis of said gas supply hole at all times.    
     
     
         4 . A plasma processing apparatus according to  claim 3 , wherein: 
 said gas passage is a spiral passage.    
     
     
         5 . A plasma processing apparatus according to  claim 4 , wherein: 
 a section of said gas passage has a shape with a thickness along the central axis of said gas supply hole set larger than a width thereof.    
     
     
         6 . A plasma processing apparatus according to  claim 1 , wherein: 
 insert members constituted of different materials are used in correspondence to different types of gas used in said plasma processing.    
     
     
         7 . A plasma processing apparatus according to  claim 1 , wherein: 
 insert members with gas passages formed in different shapes are used in correspondence to different density levels of the plasma generated inside said processing chamber.