Focus ring, substrate mounting table and plasma processing apparatus having same

Abstract

A focus ring is placed on a substrate mounting table for mounting a target substrate thereon to surround the target substrate. The focus ring converges plasma on the target substrate when the target substrate is subjected to plasma processing. The focus ring is configured to create a temperature difference in its radial direction and over its full circumference during the plasma-processing of the target substrate. The focus ring also includes a radial outer region as a higher temperature region and a radial inner region as a lower temperature region. A groove is formed between the radial outer region and the radial inner region to extend over the full circumference of the focus ring.

1 . A focus ring placed on a substrate mounting table for mounting a target substrate thereon to surround the target substrate, the focus ring converging plasma on the target substrate when the target substrate is subjected to plasma processing, wherein the focus ring is configured to create a temperature difference in its radial direction and over its full circumference during the plasma-processing of the target substrate. 
   
   
       2 . The focus ring of  claim 1 , which comprises a radial outer region as a higher temperature region and a radial inner region as a lower temperature region. 
   
   
       3 . The focus ring of  claim 2 , wherein a groove is formed between the radial outer region and the radial inner region to extend over the full circumference of the focus ring. 
   
   
       4 . The focus ring of  claim 3 , wherein the groove extends inwards from an upper surface and/or a lower surface of the focus ring over the full circumference of the focus ring and is formed not to penetrate the focus ring. 
   
   
       5 . The focus ring of  claim 3 , wherein the groove is formed to penetrate the focus ring so that the focus ring is divided into two bodies. 
   
   
       6 . The focus ring of  claim 5 , wherein the groove is formed in a labyrinth shape. 
   
   
       7 . The focus ring of  claim 2 , wherein a heat transfer unit is provided between the substrate mounting table and the radial inner region of the focus ring making contact with the substrate mounting table, and the lower temperature region is formed by heat exchange between the focus ring and the substrate mounting table. 
   
   
       8 . The focus ring of  claim 2 , wherein a temperature increasing member is mounted on a part of the focus ring, and the high temperature region is formed as the temperature increasing member is heated by ion collision during the plasma processing. 
   
   
       9 . The focus ring of  claim 2 , wherein a stepped portion is formed in a part of the focus ring, a temperature increasing member is mounted in the step portion to fill the stepped portion, and the higher temperature region is formed as the temperature increasing member is heated by ion collision during the plasma processing. 
   
   
       10 . A substrate mounting table comprising the focus ring of  claim 1 . 
   
   
       11 . The substrate mounting table of  claim 10 , further comprising a cover ring arranged to surround the focus ring and a temperature increasing member annually mounted on an upper surface of the cover ring to extend over a full circumference of the cover ring. 
   
   
       12 . A plasma processing apparatus comprising:
 a processing chamber within which a processing gas is converted into plasma by high-frequency power;   a substrate mounting table arranged within the processing chamber to mount a target substrate thereon, the target substrate being processed by the plasma; and   a focus ring mounted on the substrate mounting table to surround the target substrate,   wherein the focus ring is configured to create at least two regions of different temperatures in its radial direction and over its full circumference during the plasma-processing of the target substrate.   
   
   
       13 . The apparatus of  claim 12 , wherein the focus ring includes: a radial outer region, as a higher temperature region, extending over a full circumference of the focus ring in between an outer circumference of the focus ring and a specified point radially inwardly spaced apart from the outer circumference; and a radial inner region, as a lower temperature region, extending over the full circumference of the focus ring in between the specified point and an inner circumference of the focus ring. 
   
   
       14 . The apparatus of  claim 13 , wherein an annular groove is formed between the radial outer region and the radial inner region to extend over the full circumference of the focus ring. 
   
   
       15 . The apparatus of  claim 14 , wherein the groove extends inwards from an upper surface and/or a lower surface of the focus ring over the full circumference of the focus ring and is formed not to penetrate the focus ring. 
   
   
       16 . The apparatus of  claim 14 , wherein the groove is formed to penetrate the focus ring so that the focus ring is divided into two bodies. 
   
   
       17 . The apparatus of  claim 16 , wherein the groove is formed in a labyrinth shape. 
   
   
       18 . The apparatus of  claim 13 , further comprising a temperature increasing member mounted on a portion of the focus ring, wherein the high temperature region is formed as the temperature increasing member is heated by ion collision during the plasma processing. 
   
   
       19 . The apparatus of  claim 12 , wherein a stepped portion is formed in a part of the focus ring and a temperature increasing member is mounted in the stepped portion to fill the stepped portion. 
   
   
       20 . The apparatus of  claim 12 , further comprising a cover ring arranged to surround the focus ring and a temperature increasing member annularly mounted on an upper surface of the cover ring to extend over a full circumference of the cover ring.