Plasma processing device and plasma processing method

Abstract

That surface of an electrode plate 20 which is opposite to a susceptor 10 has a projection shape. The electrode plate 20 is fitted in an opening 26 a of shield ring 26 at a projection 20 a . At this time, the thickness of the projection 20 a is approximately the same as the thickness of the shield ring 26. Accordingly, the electrode plate 20 and the shield ring 26 form substantially the same plane. The major surface of the projection 20 a has a diameter 1.2 to 1.5 times the diameter of a wafer W. The electrode plate 20 is formed of, for example, SiC.

1 . A plasma process system ( 1 ) characterized by comprising: 
 a chamber ( 2 );    an electrode plate ( 20 ) provided with gas holes ( 19 ) for supplying a process gas into said chamber ( 2 ) and having a projection ( 20   a ); and    a shield ring ( 26 ) having an opening ( 26   a ) which is fitted over said projection ( 20   a ) and is constituted by a ring-like plate member which covers a peripheral portion of said electrode plate ( 20 ) with said projection ( 20   a ) and said opening ( 26   a ) fitted together.    
     
     
         2 . The plasma process system ( 1 ) according to  claim 1 , characterized in that said projection ( 20   a ) of said electrode plate ( 20 ), in such a state as to be fitted in said opening ( 26   a ), forms a substantially flat surface together with a major surface of said shield ring ( 26 ).  
     
     
         3 . A plasma process system ( 1 ) characterized by comprising: 
 a first electrode plate ( 10 ) on one surface of which a subject to be processed is placed; and    a second electrode plate ( 20 ) connected to a high-frequency power supply and having an opposing surface opposing said one surface in parallel and having a diameter 1.2 to 1.5 times a diameter of said one surface.    
     
     
         4 . The plasma process system ( 1 ) according to  claim 3 , characterized by further comprising a shield ring ( 26 ) which has an opening ( 26   a ) formed therein with a diameter approximately equal to the diameter of said opposing surface and covers a peripheral portion of said second electrode plate ( 20 ) in such a way that said opposing surface is exposed to the inside said opening ( 26   a ).  
     
     
         5 . The plasma process system ( 1 ) according to  claim 4 , characterized in that said opposing surface is a major surface and said second electrode plate ( 20 ) has a projection ( 20   a ) which fits in said opening ( 26   a )  
     
     
         6 . A plasma process system ( 1 ) characterized by comprising: 
 a chamber ( 2 );    an electrode plate ( 20 ) connected to a high-frequency power supply and provided with first gas holes ( 19 ) for supplying a process gas into said chamber ( 2 ); and    a shield ring ( 26 ) which is provided with second gas holes ( 26   b ), has an opening ( 26   a ) and covers a periphery of said electrode plate ( 20 ) in such a way that said electrode plate ( 20 ) is exposed to the inside of said opening ( 26   a ).    
     
     
         7 . The plasma process system ( 1 ) according to  claim 6 , characterized in that said second gas holes ( 26   b ) are laid out annually around said opening ( 26   a ) and a maximum layout diameter of said second gas holes ( 26   b ) is about 1.1 times a diameter of said opening ( 26   a ).  
     
     
         8 . The plasma process system ( 1 ) according to  claim 6 , characterized in that said exposed surface is a major surface, said electrode plate ( 20 ) has a projection ( 20   a ) which fits in said opening ( 26   a ), and a major surface of said projection ( 20   a ) forms a substantially flat surface together with said shield ring ( 26 ).  
     
     
         9 . A plasma process system ( 1 ) characterized by comprising: 
 a chamber ( 2 ) in which a predetermined plasma process is performed on a subject to be processed;    a cleaning gas supply port ( 30 ) which supplies a cleaning gas containing halogen into said chamber ( 2 ); and    an electrode plate ( 20 ) provided with gas holes ( 19 ) for supplying a process gas into said chamber ( 2 ) and so constituted as to contain a material resistive to a halogen radical.    
     
     
         10 . The plasma process system ( 1 ) according to  claim 9 , characterized in that said electrode plate ( 20 ) is so constituted as to contain a material resistive to a halogen radical rather than to silicon.  
     
     
         11 . The plasma process system ( 1 ) according to  claim 9 , characterized in that said cleaning gas is comprised of a material containing fluorine and said halogen radical is comprised of a fluorine radical.  
     
     
         12 . The plasma process system ( 1 ) according to  claim 9 , characterized in that said material resistive to said halogen radical is selected from a group of silicon carbide, carbon, aluminum, alumite, alumina and sprayed quartz alumina.  
     
     
         13 . The plasma process system ( 1 ) according to  claim 9 , characterized by further comprising: 
 a mount table ( 10 ) which is provided opposite to said electrode plate ( 20 ) and on which said subject to be processed is placed; and    a ring-like member ( 17 ) formed of a material resistive to said halogen radical.    
     
     
         14 . The plasma process system ( 1 ) according to  claim 9 , characterized in that said cleaning gas is turned into a plasma in said chamber ( 2 ) to generate said halogen radical.  
     
     
         15 . The plasma process system ( 1 ) according to  claim 9 , characterized by further comprising an activator ( 33 ) provided outside said chamber ( 2 ) and connected to said cleaning gas supply port, and 
 in that said activator ( 33 ) generates said halogen radical by activating said cleaning gas and supplies said generated halogen radical into said chamber ( 2 )  2 .    
     
     
         16 . The plasma process system ( 1 ) according to  claim 9 , characterized in that said cleaning gas is so formed as to contain an oxygen-containing material.  
     
     
         17 . A plasma process method using a plasma process system having a chamber ( 2 ) in which a predetermined plasma process is performed on a subject to be processed by generation of a plasma inside, a first electrode plate ( 10 ) on one surface of which a subject to be processed is placed, and a second electrode plate ( 20 ) connected to a high-frequency power supply and having an opposing surface opposing said one surface in parallel characterized by including the step of: 
 setting a diameter of said opposing surface to 1.2 to 1.5 tines a diameter of said one surface and supplying high-frequency power to said second electrode.    
     
     
         18 . A plasma process method using a plasma process system having a chamber ( 2 ) in which a predetermined plasma process is performed on a subject to be processed by generation of a plasma inside, an electrode plate ( 20 ) provided with first gas holes ( 19 ) for supplying a process gas into said chamber ( 2 ) and connected to a high-frequency power supply, and a shield ring ( 26 ) which is provided with second gas holes ( 26   b ), has an opening ( 26   a ) and covers a periphery of said electrode plate ( 20 ) in such a way that said electrode plate ( 20 ) is exposed to the inside of said opening ( 26   a ), characterized by including the step of spraying said gas into said chamber ( 2 ) through said first gas holes ( 19 ) and said second gas holes ( 26   b ).