Plasma processing apparatus and plasma processing method

Abstract

A substrate ( 101 ) subjected to a plasma process is placed on a first electrode ( 102 ). A magnetic field is applied to a surface of the substrate to which the plasma process is applied by magnetic field applying means ( 103 ). An auxiliary electrode ( 104 ) is provided on an outer periphery of the first electrode ( 102 ) to excite plasma on a back surface ( 105 ) thereof. Electrons in the plasma are caused to drift from a front surface ( 106 ) to a back surface ( 105 ) of the auxiliary electrode ( 104 ) and from the back surface ( 105 ) to the front surface ( 106 ) of the auxiliary electrode ( 104 ).

1 . A plasma processing apparatus comprising a first electrode ( 102 ) on which a substrate ( 101 ;  807 ) subjected to a plasma process is placed and magnetic field applying means ( 103 ) for applying a magnetic field to a surface of the substrate ( 101 ;  807 ) to which the plasma process is applied, 
 characterized in that: 
 an auxiliary electrode ( 104 ) is provided on an outer periphery of said first electrode ( 102 ) to excite plasma by the auxiliary electrode ( 104 ) so as to cause electrons in the plasma to drift from a front surface ( 106 ) to a back surface ( 105 ) of said auxiliary electrode ( 104 ) and from the back surface ( 105 ) to the front surface ( 106 ) of said auxiliary electrode ( 104 ).  
   
     
     
         2 . The plasma processing apparatus as claimed in  claim 1 , characterized in that the front surface ( 106 ) of said auxiliary electrode ( 104 ) is covered by an insulating material ( 902 ).  
     
     
         3 . The plasma processing apparatus as claimed in  claim 1  or  2 , characterized in that a level of a surface of the substrate ( 101 ) placed on said first electrode ( 102 ) and a level of the front surface of said auxiliary electrode ( 104 ) are equal to each other or within ±2 mm.  
     
     
         4 . The plasma processing apparatus as claimed in  claim 1  or  2 , characterized in that said magnetic field applying means ( 103 ) comprises a dipole ring-magnet.  
     
     
         5 . The plasma processing apparatus as claimed in  claim 1  or  2 , characterized in that a frequency f 1  of a radio frequency applied to said first electrode ( 102 ) and a frequency f 2  of a radio frequency applied to said auxiliary electrode ( 104 ) are equal to each other and phases thereof are different from each other.  
     
     
         6 . The plasma processing apparatus as claimed in  claim 1  or  2 , characterized in that a frequency f 2  of a radio frequency applied to said auxiliary electrode ( 104 ) is higher than a frequency f 1  of a radio frequency applied to said first electrode ( 102 ) (f 2 >f 1 ).  
     
     
         7 . A plasma processing method performed in a plasma processing apparatus comprising a first electrode ( 102 ) on which a substrate ( 101 ) subjected to a plasma process is placed and magnetic field applying means ( 103 ) for applying a magnetic field to a surface of the substrate ( 101 ) to which the plasma process is applied, 
 characterized by: 
 exciting plasma on at least a back surface ( 105 ) of an auxiliary electrode ( 104 ) provided on an outer periphery of said first electrode; and cause electrons in the plasma to drift from a front surface ( 106 ) to the back surface ( 105 ) of said auxiliary electrode ( 104 ) and from the back surface ( 105 ) to the front surface ( 106 ) of said auxiliary electrode ( 104 ).