Mounting table and plasma processing apparatus

Abstract

A mounting table, to which a voltage is applied, includes an electrostatic chuck having a mounting surface for mounting a target object and a rear surface opposite to the mounting surface, the electrostatic chuck having a first through-hole formed in the mounting surface; a base, which is in contact with the rear surface of the electrostatic chuck, having a second through-hole communicating with the first through-hole; a cylindrical spacer inserted in the second through-hole; and a pin accommodated in the first through-hole and the spacer. Gaps are formed between the pin and inner walls of the first through-hole and the spacer, and the gap between the first through-hole and the pin is greater than the gap between the spacer and the pin.

What is claimed is: 
     
         1 . A mounting table to which a voltage is applied, comprising:
 an electrostatic chuck having a mounting surface for mounting a target object and a rear surface opposite to the mounting surface, the electrostatic chuck having a first through-hole formed in the mounting surface;   a base, which is in contact with the rear surface of the electrostatic chuck, having a second through-hole communicating with the first through-hole;   a cylindrical spacer inserted in the second through-hole; and   a pin accommodated in the first through-hole and the spacer,   wherein gaps are formed between the pin and inner walls of the first through-hole and the spacer, and   the gap between the first through-hole and the pin is greater than the gap between the spacer and the pin.   
     
     
         2 . A mounting table to which a voltage is applied, comprising:
 an electrostatic chuck having a mounting surface for mounting a target object and a rear surface opposite to the mounting surface, having a first through-hole formed in the mounting surface;   a base, which is in contact with the rear surface of the electrostatic chuck, having a second through-hole communicating with the first through-hole; and   a pin accommodated in the first through-hole and the second through-hole,   wherein gaps are formed between the pin and inner walls of the first through-hole and the second through-hole, and   the gap between the first through-hole and the pin is greater than the gap between the second through-hole and the pin.   
     
     
         3 . The mounting table of  claim 1 , wherein the electrostatic chuck is made of ceramic and has therein an electrode, and
 the base is made of a metal.   
     
     
         4 . The mounting table of  claim 2 , wherein the electrostatic chuck is made of ceramic and has therein an electrode, and
 the base is made of a metal.   
     
     
         5 . The mounting table of  claim 1 , wherein the first through-hole is a gas hole for supplying a cold heat transfer gas. 
     
     
         6 . The mounting table of  claim 2 , wherein the first through-hole is a gas hole for supplying a cold heat transfer gas. 
     
     
         7 . The mounting table of  claim 1 , wherein the pin is a lifter pin for raising the target object from the mounting table, and
 the first through-hole is a pin through-hole.   
     
     
         8 . The mounting table of  claim 2 , wherein the pin is a lifter pin for raising the target object from the mounting table, and
 the first through-hole is a pin through-hole.   
     
     
         9 . The mounting table of  claim 1 , wherein on the assumption that a length of the gap in the first through-hole is g 1 ; a thermal expansion coefficient of the base is α 1 ; a thermal expansion coefficient of the electrostatic chuck is α 2 ; a distance from a center of the mounting surface to a center of the first through-hole is R; a diameter of the pin is D; a diameter of the second through-hole is d 2 ; and a difference between a target temperature and a reference temperature that is a temperature measured when the first through-hole and the second through-hole are coaxially disposed, the length g 1  of the gap in the first through-hole satisfies a relation of g 1 ≥(2·(R·(α 1 −α 2 )·ΔT+D)−d 2 −D)/2 
     
     
         10 . The mounting table of  claim 2 , wherein on the assumption that a length of the gap in the first through-hole is g 1 ; a thermal expansion coefficient of the base is α 1 ; a thermal expansion coefficient of the electrostatic chuck is α 2 ; a distance from a center of the mounting surface to a center of the first through-hole is R; a diameter of the pin is D; a diameter of the second through-hole is d 2 ; and a difference between a target temperature and a reference temperature that is a temperature measured when the first through-hole and the second through-hole are coaxially disposed, the length g 1  of the gap in the first through-hole satisfies a relation of g 1 ≥(2·(R·(α 1 −α 2 )·ΔT+D)−d 2 −D)/2 
     
     
         11 . A plasma processing apparatus comprising:
 a processing chamber defining a processing space where a plasma is generated;   a gas supply unit configured to supply a processing gas into the processing space; and   a mounting table provided in the processing space and configured to mount thereon a target object,   wherein the mounting table to which a voltage is applied includes:   an electrostatic chuck having a mounting surface for mounting a target object and a rear surface opposite to the mounting surface, the electrostatic chuck having a first through-hole formed in the mounting surface;   a base, which is in contact with the rear surface of the electrostatic chuck, having a second through-hole communicating with the first through-hole;   a cylindrical spacer inserted in the second through-hole; and   a pin accommodated in the first through-hole and the spacer,   wherein gaps are formed between the pin and inner walls of the first through-hole and the spacer, and   the gap between the first through-hole and the pin is greater than the gap between the spacer and the pin.   
     
     
         12 . A plasma processing apparatus comprising:
 a processing chamber defining a processing space where a plasma is generated;   a gas supply unit configured to supply a processing gas into the processing space; and   a mounting table provided in the processing space and configured to mount thereon a target object,   wherein the mounting table to which a voltage is applied includes:   an electrostatic chuck having a mounting surface for mounting a target object and a rear surface opposite to the mounting surface, the electrostatic chuck having a first through-hole formed in the mounting surface;   a base, which is in contact with the rear surface of the electrostatic chuck, having a second through-hole communicating with the first through-hole; and   a pin accommodated in the first through-hole and the second through-hole,   wherein gaps are formed between the pin and inner walls of the first through-hole and the second through-hole, and   the gap between the first through-hole and the pin is greater than the gap between the second through-hole and the pin.