Apparatus and method for plasma processing

Abstract

At the time of plasma igniting or during plasma processing, only optimizing the distance between electrodes in each case caused a limitation to the prevention of charging damage. To resolve this, a novel plasma processing method employs a plasma processing apparatus which includes an upper electrode to which first high-frequency power is applied, a lower electrode to which second high-frequency power is applied, and a lift mechanism for controlling the spacing between the upper and lower electrodes. The first high-frequency power is applied to the upper electrode to cause plasma igniting. The method is adapted to make the spacing between the upper and lower electrodes larger at least at the time of plasma extinction than during plasma processing of a wafer on the lower electrode.

1 . A plasma processing method comprising the step of plasma processing an object to be processed using a plasma processing apparatus for allowing plasma generating means to cause plasma igniting, wherein 
 an amount of charges deposited on the object to be processed at least at the time of plasma extinction is reduced.    
   
   
       2 . A plasma processing method comprising the step of plasma processing an object to be processed placed on a lower electrode using a plasma processing apparatus which has an upper electrode and the lower electrode, a spacing therebetween being adjustable, and which causes plasma igniting by applying high-frequency power to at least one of the upper and lower electrodes, wherein 
 the spacing is made larger at least at the time of plasma extinction than during plasma processing.    
   
   
       3 . The plasma processing method according to  claim 2 , wherein 
 first high-frequency power is applied to the upper electrode, and second high-frequency power having a lower frequency than the first high-frequency power is applied to the lower electrode.    
   
   
       4 . The plasma processing method according to  claim 2 , wherein 
 the lower electrode is moved away from the upper electrode to increase the spacing.    
   
   
       5 . The plasma processing method according to  claim 3 , wherein 
 the first high-frequency power is turned off after the second high-frequency power is turned off.    
   
   
       6 . The plasma processing method according to  claim 2 , wherein 
 etching is performed as the plasma processing.    
   
   
       7 . A plasma processing apparatus comprising: 
 a lower electrode for placing an object to be processed thereon;    an upper electrode disposed above the lower electrode so as to oppose it;    an adjusting mechanism for adjusting a spacing between the upper and lower electrodes by raising or lowering the lower electrode; and    a high-frequency power supply for applying high-frequency power to at least one of the upper and lower electrodes, the high-frequency power being applied to either one of the electrodes to cause plasma igniting, wherein    the adjusting mechanism has a drive mechanism for making the spacing larger at least at the time of plasma extinction than during plasma processing of the object to be processed placed on the lower electrode.    
   
   
       8 . The plasma processing apparatus according to  claim 7 , further comprising: 
 a first high-frequency power supply for applying first high-frequency power to the upper electrode; and    a second high-frequency power supply for applying second high-frequency power having a lower frequency than the first high-frequency power to the lower electrode.    
   
   
       9 . The plasma processing apparatus according to  claim 7 , wherein 
 the adjusting mechanism has a drive mechanism for moving the lower electrode away from the upper electrode.    
   
   
       10 . The plasma processing apparatus according to  claim 8 , wherein 
 the first high-frequency power is turned off after the second high-frequency power is turned off.    
   
   
       11 . The plasma processing apparatus according to  claim 7 , wherein etching is performed as the plasma processing.