Semiconductor wafer processing apparatus and method

Abstract

A wafer stage 2 for holding a semiconductor wafer in a plasma treatment apparatus by setting the wafer on the wafer stage, said wafer stage 2 comprising a base material 26 equipped with refrigerant flow paths for allowing a refrigerant for temperature adjustment to flow; a stress-reducing member 28 provided on the wafer setting side of said base material 26 and having a smaller thermal expansion coefficient than does said base material; a dielectric film 30 provided on the wafer setting side of said stress-reducing member; and a deflection-preventing member 29 provided on the wafer non-setting side of said base material and having a smaller thermal expansion coefficient than does said base material. When the wafer stage is used, the temperature of the wafer as a substrate to be processed can be controlled uniformly and very accurately.

What is claimed is:  
     
         1 . A wafer stage for holding a semiconductor wafer in a plasma treatment apparatus by setting the wafer on the wafer stage, said wafer stage comprising: 
 a base material equipped with refrigerant flow paths for allowing a refrigerant for temperature adjustment to flow,    a stress-reducing member provided on the wafer setting side of said base material and having a smaller thermal expansion coefficient than does said base material,    a dielectric film provided on the wafer setting side of said stress-reducing member, and    a deflection-preventing member provided on the wafer non-setting side of said base material and having a smaller thermal expansion coefficient than does said base material.    
     
     
         2 . The wafer stage according to  claim 1 , wherein said dielectric film is a film formed by flame spraying and composed mainly of a ceramic.  
     
     
         3 . The wafer stage according to  claim 1 , wherein said dielectric film is a film formed by chemical vapor deposition and composed mainly of a ceramic.  
     
     
         4 . The wafer stage according to  claim 1 , wherein said dielectric film is a sintered product composed mainly of a ceramic.  
     
     
         5 . The wafer stage according to  claim 4 , wherein the dielectric film comprising a sintered product composed mainly of a ceramic is brazed to said stress-reducing member or attached thereto with an adhesive.  
     
     
         6 . A wafer stage for holding a semiconductor wafer in a plasma treatment apparatus by setting the wafer on the wafer stage, said wafer stage comprising: 
 a base material equipped with refrigerant flow paths for allowing a refrigerant for temperature adjustment to flow,    a stress-reducing member provided on the wafer setting side of said base material and having a smaller thermal expansion coefficient than does said base material,    a dielectric film provided on the wafer setting side of said stress-reducing member, and    a deflection-preventing member provided on the wafer non-setting side of said base material and having a smaller thermal expansion coefficient than does said base material, wherein said stress-reducing member has a cylindrical and internally convex level difference portion with a diameter smaller than the outside diameter of a semiconductor wafer to be set thereon, and a ring member made of carbon, Si or SiC is mounted on said dielectric film around the periphery of said level difference portion.    
     
     
         7 . The wafer stage according to any one of  claims 1  to  6 , wherein said dielectric film is equipped with a plurality of electrodes for electrostatic attraction, and different potentials are supplied to the plurality of the electrodes, respectively.  
     
     
         8 . An apparatus for processing a semiconductor wafer as a substrate to be processed which comprises a wafer stage comprising: 
 a base material equipped with refrigerant flow paths for allowing a refrigerant for temperature adjustment to flow,    a stress-reducing member provided on the wafer setting side of said base material and having a smaller thermal expansion coefficient than does said base material,    a dielectric film provided on the wafer setting side of said stress-reducing member, and    a deflection-preventing member provided on the wafer non-setting side of said base material and having a smaller thermal expansion coefficient than does said base material, wherein a semiconductor wafer is held in a plasma treatment apparatus by setting the wafer on said wafer stage, said processing apparatus being equipped with a control unit for controlling the temperature of the refrigerant to be allowed to flow along the refrigerant flow paths, on the basis of the temperature of said substrate to be processed.    
     
     
         9 . A method for processing a semiconductor wafer as a substrate to be processed which uses a wafer stage comprising: 
 a base material equipped with refrigerant flow paths for allowing a refrigerant for temperature adjustment to flow,    a stress-reducing member provided on the wafer setting side of said base material and having a smaller thermal expansion coefficient than does said base material,    a dielectric film provided on the wafer setting side of said stress-relaxing member, and    a deflection-preventing member provided on the wafer non-setting side of said base material and having a smaller thermal expansion coefficient than does said base material; and comprises holding a semiconductor wafer in a plasma treatment apparatus by setting the wafer on said wafer stage, wherein the temperature of the refrigerant to be allowed to flow along the refrigerant flow paths is controlled on the basis of the temperature of said substrate to be processed.    
     
     
         10 . A wafer stage comprising: 
 a base material equipped with refrigerant flow paths for allowing a refrigerant for temperature adjustment to flow,    a stress-reducing member brazed to the wafer setting side of said base material and having a smaller thermal expansion coefficient than does said base material,    a dielectric film provided on the wafer setting side of said stress-relaxing member, and    a deflection-preventing member brazed to the wafer non-setting side of said base material and having a smaller thermal expansion coefficient than does said base material.