Plasma processing apparatus

Abstract

A plasma etching apparatus includes a chamber, a susceptor in the chamber, an electrostatic chuck provided on the susceptor, and a high frequency power supply for supplying a high frequency power for generating a plasma in the chamber. The plasma etching apparatus also includes a gas inlet port provided in the chamber and configured to supply an etching gas, and a ring disposed in an outer periphery of a substrate supported by the electrostatic chuck that is positioned over the susceptor. An inner diameter of the ring is larger than an outer diameter of the substrate. The ring is separately positioned at a separation distance over the susceptor. The substrate is etched by using the plasma generated by the high frequency power that is supplied by the high frequency power supply. The separation distance between the ring and the susceptor is adjustable when the substrate is etched.

What is claimed is: 
     
         1 . A plasma etching apparatus comprising:
 a chamber;   a susceptor in the chamber;   an electrostatic chuck provided on the susceptor;   a high frequency power supply for supplying a high frequency power for generating a plasma in the chamber;   a gas inlet port provided in the chamber and configured to supply an etching gas; and   a ring disposed in an outer periphery of a substrate supported by the electrostatic chuck that is positioned over the susceptor, an inner diameter of the ring being larger than an outer diameter of the substrate, wherein:
 the ring is separately positioned at a separation distance over the susceptor, 
 the substrate is etched by using the plasma generated by the high frequency power that is supplied by the high frequency power supply, and 
 the separation distance between the ring and the susceptor is adjustable when the substrate is etched. 
   
     
     
         2 . The plasma etching apparatus of  claim 1 , wherein the separation distance is adjusted to maintain verticality of an etching process in a vicinity of an edge of the substrate. 
     
     
         3 . The plasma etching apparatus of  claim 1 , wherein the separation distance is controlled such that an inner peripheral surface of the ring is positioned to face a side of the outer periphery of the substrate. 
     
     
         4 . The plasma etching apparatus of  claim 1 , further comprising a supporting rod that is driven by an actuator for adjusting the separation distance between the ring and the susceptor and is inserted through a through hole formed in the susceptor. 
     
     
         5 . The plasma etching apparatus of  claim 4 , wherein the through hole is provided with a seal member. 
     
     
         6 . The plasma etching apparatus of  claim 1 , further comprising an inner ring disposed in an inner side of the ring, wherein:
 an inner diameter of the inner ring is smaller than the outer diameter of the substrate, and is smaller than the inner diameter of the ring, and   an outer diameter of the inner ring is larger than the outer diameter of the substrate, and is smaller than an outer diameter of the ring.   
     
     
         7 . The plasma etching apparatus of  claim 6 , wherein:
 an inner peripheral portion of the inner ring is positioned under the substrate and overlaps an outer peripheral portion of the substrate in a top view, and   an outer peripheral portion of the inner ring is positioned under the ring and overlaps at least an inner peripheral portion of the ring.   
     
     
         8 . The plasma etching apparatus of  claim 7 , wherein a lower surface of the ring and an upper surface of the inner ring are separated from each other. 
     
     
         9 . The plasma etching apparatus of  claim 1 , wherein the high frequency power supply is coupled to the susceptor. 
     
     
         10 . The plasma etching apparatus of  claim 1 , further comprising a cylindrical insulating supporting portion surrounding an outer periphery of the susceptor. 
     
     
         11 . The plasma etching apparatus of  claim 8 , wherein the susceptor comprises an inner peripheral portion and an outer peripheral portion, a top surface of the inner peripheral portion being positioned over a top surface of the outer peripheral portion. 
     
     
         12 . The plasma etching apparatus of  claim 11 , wherein the inner ring is positioned between the outer peripheral portion of the susceptor and the substrate. 
     
     
         13 . The plasma etching apparatus of  claim 12 , wherein:
 the electrostatic chuck is positioned over the inner peripheral portion of the susceptor, and   the inner peripheral portion of the inner ring is adjacent to the electrostatic chuck and the inner periphery portion of the susceptor.   
     
     
         14 . The plasma etching apparatus of  claim 13 , wherein the ring is positioned over the outer peripheral portion of the susceptor and the outer peripheral portion of the inner ring. 
     
     
         15 . A plasma etching apparatus comprising:
 a chamber;   a susceptor in the chamber;   an electrostatic chuck provided on the susceptor;   a high frequency power supply for supplying a high frequency power for generating a plasma in the chamber;   a gas inlet port provided in the chamber and configured to supply an etching gas; and   a ring disposed in an outer periphery of a substrate supported by the electrostatic chuck that is positioned over the susceptor, an inner diameter of the ring being larger than an outer diameter of the substrate, wherein:
 the ring is separately positioned at a separation distance over the susceptor, 
 the substrate is etched by using the plasma generated by the high frequency power that is supplied by the high frequency power supply, and 
 the ring is positioned by adjusting the separation distance such that a top surface of the ring is level with a top surface of the substrate. 
   
     
     
         16 . The plasma etching apparatus of  claim 15 , further comprising a supporting rod that is driven by an actuator for adjusting the separation distance between the ring and the susceptor and is inserted through a through hole formed in the susceptor. 
     
     
         17 . The plasma etching apparatus of  claim 15 , further comprising an inner ring disposed in an inner side of the ring, wherein:
 an inner diameter of the inner ring is smaller than the outer diameter of the substrate, and is smaller than the inner diameter of the ring,   an outer diameter of the inner ring is larger than the outer diameter of the substrate, and is smaller than an outer diameter of the ring,   an inner peripheral portion of the inner ring is positioned under the substrate and overlaps an outer peripheral portion of the substrate in a top view, and   an outer peripheral portion of the inner ring is positioned under the ring and overlaps at least an inner peripheral portion of the ring.   
     
     
         18 . A plasma etching apparatus comprising:
 a chamber;   a susceptor in the chamber;   an electrostatic chuck provided on the susceptor;   a high frequency power supply for supplying a high frequency power for generating a plasma in the chamber;   a gas inlet port provided in the chamber and configured to supply an etching gas; and   a ring disposed in an outer periphery of a substrate supported by the electrostatic chuck that is positioned over the susceptor, an inner diameter of the ring being larger than an outer diameter of the substrate, wherein:
 the ring is separately positioned at a separation distance over the susceptor, 
 the substrate is etched by using the plasma generated by the high frequency power that is supplied by the high frequency power supply, and 
 the ring is positioned by adjusting the separation distance such that a top surface of the ring is arranged over a top surface of the substrate. 
   
     
     
         19 . The plasma etching apparatus of  claim 18 , further comprising a supporting rod that is driven by an actuator for adjusting the separation distance between the ring and the susceptor and is inserted through a through hole formed in the susceptor. 
     
     
         20 . The plasma etching apparatus of  claim 18 , further comprising an inner ring disposed in an inner side of the ring, wherein:
 an inner diameter of the inner ring is smaller than the outer diameter of the substrate, and is smaller than the inner diameter of the ring,   an outer diameter of the inner ring is larger than the outer diameter of the substrate, and is smaller than an outer diameter of the ring,   an inner peripheral portion of the inner ring is positioned under the substrate and overlaps an outer peripheral portion of the substrate in a top view, and   an outer peripheral portion of the inner ring is positioned under the ring and overlaps at least an inner peripheral portion of the ring.