Plasma processing apparatus

Abstract

The plasma processing apparatus includes main electrodes 5, 31 opposed to each other with a plasma processing space 15 interposed therebetween. The plasma processing apparatus further has a side electrode 6 opposed to side faces 5 B- 1, 5 B- 2 of the main electrode 5, as well as a side electrode 32 opposed to side faces 31 B- 1, 31 B- 2 of the main electrode 31. Therefore, in addition to the plasma processing space 15 between the main electrode 5 and the main electrode 31, an electric field can be formed in spaces between the side faces of the main electrodes 5, 31 and the side electrodes 6, 32, the spaces serving as predischarge areas 16 - 1, 16 - 2. By this electric field, processing gas present in the predischarge areas 16 - 1, 16 - 2 can be transformed into plasma. Electrons and excitation species of the plasma generated in these predischarge areas 16 - 1, 16 - 2 can be supplied directly to the plasma processing space 15.

1 . A plasma processing apparatus comprising: 
 a gas supply section for supplying a specified processing gas to a plasma processing space where a plasma processing object to be processed is placed;    a first electrode which is opposed to the plasma processing space and which generates an electric field in the plasma processing space;    a second electrode which is opposed to the first electrode with the plasma processing space interposed therebetween;    a third electrode which is opposed to a side face of the first electrode with a specified gap, the side face being adjacent to an opposing face of the first electrode facing the plasma processing space; and    a first power supply section for supplying a first electric power to the first electrode.    
   
   
       2 . The plasma processing apparatus as claimed in  claim 1 , further comprising: 
 a first dielectric portion with which the opposing face and the side face of the first electrode are covered; and    a second dielectric portion with which a side face of the third electrode opposed to the side face of the first electrode is covered, wherein    the first dielectric portion and the second dielectric portion are opposed to each other with a specified gap therebetween.    
   
   
       3 . The plasma processing apparatus as claimed in  claim 1 , wherein 
 the third electrode is grounded,    a second power supply section for supplying a second electric power to the second electrode is provided,    the first electric power supplied to the first electrode by the first power supply section and the second electric power supplied to the second electrode by the second power supply section are different from each other in at least one of phase and amplitude, and wherein    the first electric power and the second electric power are    RF power, or pulse wave electric power, or electric power obtained by switching RF power and pulse wave electric power, or electric power in which RF power and pulse wave electric power are superimposed on each other.    
   
   
       4 . The plasma processing apparatus as claimed in  claim 1 , wherein 
 the apparatus has a structure that processing gas supplied by the gas supply section, after passing through the gap between the side face of the first electrode and the third electrode, passes through the plasma processing space between the first electrode and the second electrode.    
   
   
       5 . The plasma processing apparatus as claimed in  claim 1 , wherein 
 the gas supply section comprises:    a gas jet port for supplying the processing gas to the gap between the first electrode and the third electrode; and    an opening controller for changing at least one of opening area and opening configuration of the gas jet port.    
   
   
       6 . The plasma processing apparatus as claimed in  claim 2 , further comprising 
 a dielectric coat formed on the opposing face and the side face of the first electrode, wherein    the first dielectric portion covers the dielectric coat.    
   
   
       7 . The plasma processing apparatus as claimed in  claim 6 , wherein 
 the gap between the first electrode and the first dielectric portion is not more than 500 μm.