Focus ring and plasma processing apparatus

Abstract

A focus ring to be detachably attached to a top surface of an outer peripheral portion of a mounting table in a processing chamber, includes: an annular main body having a back surface to be attached to the top surface of the outer peripheral portion of the mounting table. And a thermally conductive sheet fixed to the annular main body, the thermally conductive sheet being interposed between the annular main body and the top surface of the outer peripheral portion of the mounting. The thermally conductive sheet is fixed as one unit to the annular main body by coating an unvulcanized rubber on one surface of the thermally conductive sheet, bringing said one surface into contact with the annular main body, and heating the thermally conductive sheet and the annular main body to vulcanize and to adhere the thermally conductive sheet to the annular main body.

What is claimed is: 
     
         1 . A focus ring to be detachably attached to a top surface of an outer peripheral portion of a mounting table for mounting thereon a substrate to be processed in a processing chamber, comprising;
 an annular main body having a back surface to be attached to the top surface of the outer peripheral portion of the mounting table; and   a thermally conductive sheet fixed to the back surface of the annular main body, the thermally conductive sheet being interposed between the annular main body and the top surface of the outer peripheral portion of the mounting table in the case of attaching the annular main body to the top surface of the outer peripheral portion of the mounting table,   wherein the thermally conductive sheet is fixed as one unit to the back surface of the annular main body by coating an unvulcanized rubber, a material of which is the same as a material of the thermally conductive sheet, on one surface of the thermally conductive sheet, bringing said one surface into contact with the back surface of the annular main body, and heating the thermally conductive sheet and the annular main body to vulcanize the thermally conductive sheet and to adhere the thermally conductive sheet to the back surface of the annular main body.   
     
     
         2 . The focus ring of  claim 1 , wherein said heating the thermally conductive sheet and the annular main body is performed at a temperature and for a period of time under a condition that the thermally conductive sheet is vulcanized and adhered to the annular main body without changing flexibility and thermal conductivity of the thermally conductive sheet. 
     
     
         3 . The focus ring of  claim 1 , wherein the thermally conductive sheet is formed in a sheet form by vulcanizing and hardening an unvulcunized rubber obtained by adding carbon fiber as a filler for ensuring thermal conductivity to liquid silicon rubber, and the heating is performed at 100° C. to 150° C. at which the flexibility and the thermal conductivity of the thermally conductive sheet are not changed. 
     
     
         4 . The focus ring of  claim 1 , wherein the thermally conductive sheet is formed in a sheet form by vulcanizing and hardening an unvulcanized rubber obtained by adding carbon fiber as a filler for ensuring thermal conductivity to liquid fluorine rubber, and the heating is performed at 130° C. to 170° C. at which the flexibility and the thermal conductivity of the thermally conductive sheet are not changed. 
     
     
         5 . A plasma processing apparatus comprising:
 a depressurizable processing chamber configured to accommodate a substrate to be processed;   a mounting table provided in the processing chamber and configured to mount thereon the substrate, the mounting table having therein a temperature control unit; and   an annular focus ring provided on a top surface of an outer peripheral portion of the mounting table so as to surround a peripheral portion of the substrate,   wherein the focus ring includes:   an annular main body having a back surface attached to the top surface of the outer peripheral portion of the mounting table; and   a thermally conductive sheet fixed to the back surface of the annular main body, the thermally conductive sheet being interposed between the annular main body and the top surface of the outer peripheral portion of the mounting table,   wherein the thermally conductive sheet is fixed as one unit to the back surface of the annular main body by coating an unvulcanized rubber, a material of which is the same as a material of the thermally conductive sheet, on one surface of the thermally conductive sheet, bringing said one surface into contact with the back surface of the annular main body, and heating the thermally conductive sheet and the annular main body to vulcanize the thermally conductive sheet and to adhere the thermally conductive sheet to the back surface of the annular main body.   
     
     
         6 . The plasma processing apparatus of  claim 5 , wherein the thermally conductive sheet is disposed on the top surface of the outer peripheral portion of the mounting table without using a mechanical pressing unit. 
     
     
         7 . The plasma processing apparatus of  claim 5 , wherein said heating the thermally conductive sheet and the annular main body is performed at a temperature and for a period of time under a condition that the thermally conductive sheet is vulcanized and adhered to the annular main body without changing flexibility and thermal conductivity of the thermally conductive sheet. 
     
     
         8 . The plasma processing apparatus of  claim 5 , wherein the thermally conductive sheet is formed in a sheet form by vulcanizing and hardening an unvulcanized rubber obtained by adding carbon fiber as a filler for ensuring thermal conductivity to liquid silicon rubber, and the heating is performed at 100° C. to 150° C. at which the flexibility and the thermal conductivity of the thermally conductive sheet are not changed. 
     
     
         9 . The plasma processing apparatus of  claim 5 , wherein the thermally conductive sheet is formed in a sheet form by vulcanizing and hardening an unvulcanized rubber obtained by adding carbon fiber as a filler for ensuring thermal conductivity to liquid fluorine rubber, and the heating is performed at  130 ° C. to  170 ° C. at which the flexibility and the thermal conductivity of the thermally conductive sheet are not changed. 
     
     
         10 . A method for manufacturing a focus ring to be detachably attached to a top surface of an outer peripheral portion of a mounting table for mounting thereon a substrate to be processed in a processing chamber, the method comprising;
 preparing an annular main body having a back surface to be attached to the top surface of the outer peripheral portion of the mounting table; and   fixing a thermally conductive sheet to the back surface of the annular main body by coating an unvulcanized rubber, a material of which is the same as a material of the thermally conductive sheet, on one surface of the thermally conductive sheet, bringing said one surface into contact with the back surface of the annular main body, and heating the thermally conductive sheet and the annular main body to vulcanize the thermally conductive sheet and to adhere the thermally conductive sheet to the back surface of the annular main body.   
     
     
         11 . The method of  claim 10 , wherein said heating the thermally conductive sheet and the annular main body is performed at a temperature and for a period of time under a condition that the thermally conductive sheet is vulcanized and adhered to the annular main body without changing flexibility and thermal conductivity of the thermally conductive sheet. 
     
     
         12 . The method of  claim 10 , wherein the thermally conductive sheet is formed in a sheet form by vulcanizing and hardening an unvulcunized rubber obtained by adding carbon fiber as a filler for ensuring thermal conductivity to liquid silicon rubber, and the heating is performed at 100° C. to 150° C. at which the flexibility and the thermal conductivity of the thermally conductive sheet are not changed. 
     
     
         13 . The method of  claim 10 , wherein the thermally conductive sheet is formed in a sheet form by vulcanizing and hardening an unvulcanized rubber obtained by adding carbon fiber as a filler for ensuring thermal conductivity to liquid fluorine rubber, and the heating is performed at 130° C. to 170° C. at which the flexibility and the thermal conductivity of the thermally conductive sheet are not changed.