Plasma processing apparatus

Abstract

A plasma processing method for processing a sample by reducing a pressure within a processing chamber, including mounting the sample on a sample holder disposed in the processing chamber, and processing using a plasma generated in the processing chamber above the sample holder while supplying a gas for heat transfer to a space between a surface of the sample holder having the sample mounted thereon and a rear surface of the sample. The sample holder has a plurality of substantially ring-shaped depressed portions at the surface where the sample is mounted. A pressure in a space between the depressed portions arranged at a central portion of the sample holder with respect to outer circumferential portion and the sample is set to be lower than a pressure in a space between the depressed portions at the outer circumferential portion and the sample.

1 . A plasma processing apparatus for processing a sample with a plasma generated by using a processing gas, the apparatus comprising:
 a processing chamber having an inner space reduced in pressure;   a sample holder on which said sample is placed, said sample holder being disposed in said processing chamber, wherein at least one refrigerant flow path is disposed inside said sample holder;   a plurality of openings through which said processing gas is introduced into said processing chamber, said plurality of openings being located above the sample holder; and   an evacuating opening disposed under the sample holder through which the processing chamber is evacuated;   wherein said sample holder includes:
 an electrode disposed inside the sample holder which electrostatically adsorbs said sample on a surface of the sample holder, 
 a ring-shaped projecting partition disposed concentrically on a surface of said sample holder to have a surface thereof in contact with a surface of said sample and partitions a space between the surface of the sample and the surface of the sample holder into a plurality of regions next to each other, 
 a plurality of second openings each of which is located in a corresponding one of said plurality of regions, to introduce a heat transfer gas for heat transfer therethrough, and 
 a third opening located in a circumferentially outer region of said plurality of regions, to allow the heat transfer gas in the circumferentially outer region to flow out therethrough and exhausted, whereby said heat transfer gas in each of said plurality of regions are adjustable in different pressure when said sample is electrostatically adsorbed on the surface of said sample holder. 
   
   
   
       2 . The plasma processing apparatus of  claim 1 , wherein said circumferentially outer region is substantially evacuated through said third opening. 
   
   
       3 . A plasma processing apparatus for processing a sample with a plasma generated by using a processing gas, the apparatus comprising:
 a processing chamber having an inner space reduced in pressure;   a sample holder on which said sample is placed, said sample holder being disposed in said processing chamber, wherein at least one refrigerant flow path is disposed inside said sample holder; and   a plurality of openings through which said processing gas is introduced into said processing chamber, said plurality of openings being located above the sample holder,   wherein said sample holder includes:
 an electrode disposed inside the sample holder which electrostatically adsorbs said sample on the surface of the sample holder, 
 plural depressed portions over which said sample is placed, the plural depressed portions being disposed substantially concentrically next to each other in a surface of the sample holder, 
 a ring-shaped projection partition disposed on a surface said sample holder to have a surface thereof in contact with a surface of said sample holder and partitions said plural depressed portions between the surface of the sample and the surface of said sample holder into a plurality of regions, 
 a plurality of second openings each of which is located in a corresponding one of said plurality of regions, to introduce a heart transfer gas for heat transfer therethrough, and 
 a third opening located in a circumferentially outer region of said plurality of regions, to allow the heat transfer gas in the circumferentially outer region to flow out therethrough and exhausted, whereby said heat transfer gas in each of said plurality of regions are adjustable in different pressure when said sample is electrostatically adsorbed on a surface of said sample holder. 
   
   
   
       4 . The plasma processing apparatus of  claim 3 , wherein said circumferentially outer region is substantially evacuated through said third opening. 
   
   
       5 . The plasma processing apparatus of  claim 1 , wherein:
 a plurality of said refrigerant flow paths extend through inside of said sample holder, said plurality of refrigerant flow paths being disposed in inner or central portions and other peripheral portions of inside the sample holder, respectively, to allow refrigerants adjusted to different temperatures to flow therethrough.   
   
   
       6 . The plasma processing apparatus of  claim 3 , wherein:
 a plurality of said refrigerant flow paths extend through inside of said sample holder, said plurality of refrigerant flow paths each extending through an inside of said sample holder, said plurality of refrigerant flow paths being disposed in inner or central portions and other peripheral portions of inside the sample holder, respectively, to allow refrigerants adjusted to different temperatures to flow therethrough.   
   
   
       7 . The plasma processing apparatus of  claim 1 , wherein said plurality of regions are divided into through regions further comprising:
 a controller which adjustable a pressure of said heat transfer gas in the respective regions.   
   
   
       8 . The plasma processing apparatus of  claim 3 , further comprising:
 a controller which adjustable a pressure of said heat transfer gas in the respective region.