Plasma processing apparatus and plasma processing method

Abstract

A plane parallel plasma processing apparatus includes an impedance adjustment unit having a capacitive component, which is disposed between a lower electrode and a processing chamber. The impedance adjustment unit adjusts the value of the impedance over the path extending from an upper electrode to a grounded casing of a matching circuit via plasma, the lower electrode and the wall of the processing chamber to a level lower than the value of the impedance over the path extending from the upper electrode to the grounded casing of the matching circuit via the plasma and the wall of the processing chamber, and thus, highly uniform plasma can be generated by minimizing the generation of plasma in the space between the cathode electrode and the processing chamber wall.

1 . A plasma processing apparatus for processing a substrate with plasma generated from a process gas by supplying high-frequency power into a processing chamber, comprising: 
 a cathode electrode and an anode electrode facing opposite each other on an upper side and a lower side inside the processing chamber and insulated from the processing chamber;    a high-frequency power source having one end thereof connected to the cathode electrode via a matching circuit; and    an impedance adjustment unit having one end thereof connected to the anode electrode and another end thereof connected to the processing chamber and containing a capacitive component, wherein:    the substrate is placed on either the cathode electrode or the anode electrode that is located on the lower side; and    the impedance adjustment unit adjusts a value of impedance occurred in a path extending from the cathode electrode to a grounded casing of the matching circuit via the plasma, the anode electrode and a wall of the processing chamber to a level lower than a value of impedance occurred in a path extending from the cathode electrode to the grounded casing of the matching circuit via the plasma and the wall of the processing chamber.    
   
   
       2 . The plasma processing apparatus according to  claim 1 , wherein: 
 the impedance adjustment unit adjusts the value of the impedance occurred in the path extending from the cathode electrode to the grounded casing of the matching circuit via the plasma, the anode electrode and the wall of the processing chamber so as to minimize.    
   
   
       3 . The plasma processing apparatus according to  claim 1 , wherein: 
 the impedance adjustment unit sets the value of the impedance occurred in the path extending from the cathode electrode to the grounded casing of the matching circuit via the plasma, the anode electrode and the wall of the processing chamber so as to flow a current to the anode electrode within a range of 10% of a maximum value of the current flowing to the anode electrode by adjusting the value of the impedance by controlling the current flowing to the anode electrode.    
   
   
       4 . The plasma processing apparatus according to  claim 1 , wherein: 
 the impedance adjustment unit is constituted so as to be eneble to vary the value of the impedance.    
   
   
       5 . The plasma processing apparatus according to  claim 1 , further comprising: 
 a control unit memorizing impedance adjustment data related to various plasma processing types, reading out the impedance adjustment data corresponding to a plasma processing type selected from the various plasma processing types and outputting a control signal for adjusting the value of the impedance to the impedance adjustment unit based on the impedance adjustment data.    
   
   
       6 . The plasma processing apparatus according to  claim 1 , wherein: 
 the impedance adjustment unit is constituted with a dielectric member having the capacitive component and be located between the anode electrode and the processing chamber.    
   
   
       7 . The plasma processing apparatus according to  claim 1 , wherein: 
 a plurality of impedance adjustment units are provided and the plurality of the impedance adjustment units are individually connected on one end thereof to the anode electrode at positions distanced from one another along the longish side of the anode electrode.    
   
   
       8 . A plasma processing apparatus for processing a substrate with plasma generated from a process gas by supplying high-frequency power into a processing chamber, comprising: 
 an upper electrode and a lower electrode facing opposite each other on an upper side and a lower side inside the processing chamber and insulated from the processing chamber;    a first high-frequency power source having one end thereof connected to the upper electrode via a first matching circuit and supplying the high-frequency power within a range of 10 MHz to 30 MHz;    a second high-frequency power source having one end thereof connected to the lower electrode via a second matching circuit and supplying the high-frequency power within a range of 2 MHz to 6 MHz;    a first impedance adjustment unit having one end thereof connected to the lower electrode and another end thereof connected to the processing chamber and containing a capacitive component; and    a second impedance adjustment unit having one end thereof connected to the upper electrode and another end thereof connected to the processing chamber and containing a capacitive component, wherein:    the substrate is placed on the lower electrode;    the first impedance adjustment unit adjusts a value of impedance occurred in a path extending from the upper electrode to a grounded casing of the first matching circuit via the plasma, the lower electrode and a wall of the processing chamber by the high-frequency power of the first high-frequency power source to a level lower than a value of impedance occurred in a path extending from the upper electrode to the grounded casing of the first matching circuit via the plasma and the wall of the processing chamber by the high-frequency power of the first high-frequency power source; and    the second impedance adjustment unit adjusts a value of impedance occurred in a path extending from the lower electrode to a grounded casing of the second matching circuit via the plasma, the upper electrode and the wall of the processing chamber by the high-frequency power of the second high-frequency power source to a level lower than a value of impedance occurred in a path extending from the lower electrode to the grounded casing of the second matching circuit via the plasma and the wall of the processing chamber by the high-frequency power of the second high-frequency power source.    
   
   
       9 . The plasma processing apparatus according to  claim 8 , wherein: 
 the first impedance adjustment unit adjusts the value of the impedance occurred in the path extending from the upper electrode to the grounded casing of the first matching circuit via the plasma, the lower electrode and the wall of the processing chamber by the high-frequency power of the first high-frequency power source so as to minimize; and    the second impedance adjustment unit adjusts the value of the impedance occurred in the path extending from the lower electrode to the grounded casing of the second matching circuit via the plasma, the upper electrode and the wall of the processing chamber by the high-frequency power of the second high-frequency power source so as to minimize.    
   
   
       10 . The plasma processing apparatus according to  claim 8 , wherein: 
 the first impedance adjustment unit sets the value of the impedance so as to flow a current to the lower electrode within a range of 10% of a maximum value of the current flowing to the lower electrode by adjusting the value of the impedance by controlling the current of the frequency of the first high-frequency power source; and    the second impedance adjustment unit sets the value of the impedance so as to flow a current to the upper electrode within a range of 10% of a maximum value of the current flowing to the upper electrode by adjusting the value of the impedance by controlling the current of the frequency of the second high-frequency power.    
   
   
       11 . The plasma processing apparatus according to  claim 8 , wherein: 
 the first impedance adjustment unit and the second impedance adjustment unit are constituted so as to be enable to vary the value of the impedance corresponding to the frequency of the first high-frequency power source and the value of the impedance corresponding to the frequency of the second high-frequency power source respectively.    
   
   
       12 . The plasma processing apparatus according to  claim 8 , further comprising: 
 a control unit memorizing impedance adjustment data for the first impedance adjustment unit and impedance adjustment data for the second impedance adjustment unit related to various plasma processing types, reading out the impedance adjustment data for the first impedance adjustment unit and the impedance adjustment data for the second impedance adjustment unit corresponding to a plasma processing type selected from the various plasma processing types and outputting a control signal for adjusting the value of the impedance to the first impedance adjustment unit and the second impedance adjustment unit based on the impedance adjustment data for the first impedance adjustment unit and the impedance adjustment data for the second impedance adjustment unit.    
   
   
       13 . The plasma processing apparatus according to  claim 8 , wherein: 
 the first impedance adjustment unit is constituted with a dielectric member having the capacitive component and be located between the lower electrode and the processing chamber; and    the second impedance adjustment unit is constituted with a dielectric member having the capacitive component and be located between the upper electrode and the processing chamber.    
   
   
       14 . The plasma processing apparatus according to  claim 8 , wherein: 
 a plurality of first impedance adjustment units are provided and the plurality of the first impedance adjustment units are individually connected on one end thereof to the lower electrode at positions distanced from one another along the longish side of the lower electrode; and    a plurality of second impedance adjustment units are provided and the plurality of the second impedance adjustment units are individually connected on one end thereof to the upper electrode at positions distanced from one another along the longish side of the upper electrode.    
   
   
       15 . A plasma processing apparatus for processing a substrate with plasma generated from a process gas by supplying high-frequency power into a processing chamber, comprising: 
 an upper electrode and a lower electrode facing opposite each other on an upper side and a lower side inside the processing chamber and insulated from the processing chamber;    a first high-frequency power source having one end thereof connected to the lower electrode via a first matching circuit and supplying the high-frequency power within a range of 10 MHz to 30 MHz;    a second high-frequency power source having one end thereof connected to the lower electrode via a second matching circuit and supplying the high-frequency power within a range of 2 MHz to 6 MHz; and    a first impedance adjustment unit and a second impedance adjustment unit having one end thereof connected to the upper electrode and another end thereof connected to the processing chamber and containing a capacitive component respectively, wherein:    the substrate is placed on the lower electrode;    the first impedance adjustment unit adjusts a value of impedance occurred in a path extending from the lower electrode to a grounded casing of the first matching circuit via the plasma, the upper electrode and a wall of the processing chamber by the high-frequency power of the first high-frequency power source to a level lower than a value of impedance occurred in a path extending from the lower electrode to the grounded casing of the first matching circuit via the plasma and the wall of the processing chamber by the high-frequency power of the first high-frequency power source; and    the second impedance adjustment unit adjusts a value of impedance occurred in a path extending from the lower electrode to a grounded casing of the second matching circuit via the plasma, the upper electrode and the wall of the processing chamber by the high-frequency power of the second high-frequency power source to a level lower than a value of impedance occurred in a path extending from the lower electrode to the grounded casing of the second matching circuit via the plasma and the wall of the processing chamber by the high-frequency power of the second high-frequency power source.    
   
   
       16 . The plasma processing apparatus according to  claim 15 , wherein: 
 the first impedance adjustment unit adjusts the value of the impedance occurred in the path extending from the lower electrode to the grounded casing of the first matching circuit via the plasma, the upper electrode and the wall of the processing chamber by the high-frequency power of the first high-frequency power source so as to minimize; and    the second impedance adjustment unit adjusts the value of the impedance occurred in the path extending from the lower electrode to the grounded casing of the second matching circuit via the plasma, the upper electrode and the wall of the processing chamber by the high-frequency power of the second high-frequency power source so as to minimize.    
   
   
       17 . The plasma processing apparatus according to  claim 15 , wherein: 
 the first impedance adjustment unit sets the value of the impedance so as to flow a current to the upper electrode within a range of 10% of a maximum value of the current flowing to the upper electrode by adjusting the value of the impedance by controlling the current of the frequency of the first high-frequency power source; and    the second impedance adjustment unit sets the value of the impedance so as to flow a current to the upper electrode within a range of 10% of a maximum value of the current flowing to the upper electrode by adjusting the value of the impedance by controlling the current of the frequency of the second high-frequency power source.    
   
   
       18 . The plasma processing apparatus according to  claim 15 , wherein: 
 the first impedance adjustment unit and the second impedance adjustment unit are constituted so as to be enable to vary the value of the impedance corresponding to the frequency of the first high-frequency power source and the value of the impedance corresponding to the frequency of the second high-frequency power source respectively.    
   
   
       19 . The plasma processing apparatus according to  claim 15 , further comprising: 
 a control unit memorizing impedance adjustment data for the first impedance adjustment unit and impedance adjustment data for the second impedance adjustment unit related to various plasma processing types, reading out the impedance adjustment data for the first impedance adjustment unit and the impedance adjustment data for the second impedance adjustment unit corresponding to a plasma processing type selected from the various plasma processing types, outputting a control signal for adjusting the value of the impedance to the first impedance adjustment unit and outputting a control signal for adjusting the value of the impedance to the second impedance adjustment unit.    
   
   
       20 . The plasma processing apparatus according to  claim 15 , wherein: 
 the first impedance adjustment unit is constituted with a dielectric member having the capacitive component and be located between the upper electrode and the processing chamber; and    the second impedance adjustment unit is constituted with a dielectric member having the capacitive component and be located between the upper electrode and the processing chamber.    
   
   
       21 . The plasma processing apparatus according to  claim 15 , wherein: 
 a plurality of first impedance adjustment units are provided and the plurality of the first impedance adjustment units are individually connected on one end thereof to the lower electrode at positions distanced from one another along the longish side of the lower electrode; and    a plurality of second impedance adjustment units are provided and the plurality of the second impedance adjustment units are individually connected on one end thereof to the lower electrode at positions distanced from one another along the longish side of the lower electrode.    
   
   
       22 . The plasma processing apparatus according to  claim 1 , wherein: 
 an area of the substrate is equal to or greater than 1 m 2 .    
   
   
       23 . The plasma processing apparatus according to  claim 8 , wherein: 
 an area of the substrate is equal to or greater than 1 m 2 .    
   
   
       24 . The plasma processing apparatus according to  claim 15 , wherein: 
 an area of the substrate is equal to or greater than 1 m 2 .    
   
   
       25 . The plasma processing apparatus according to  claim 22 , wherein: 
 a sum of the high-frequency power used in the plasma processing apparatus is equal to or greater than 10 kW.    
   
   
       26 . The plasma processing apparatus according to  claim 23 , wherein: 
 a sum of the high-frequency power used in the plasma processing apparatus is equal to or greater than 10 kW.    
   
   
       27 . The plasma processing apparatus according to  claim 24 , wherein: 
 a sum of the high-frequency power used in the plasma processing apparatus is equal to or greater than 10 kW.    
   
   
       28 . The plasma processing apparatus according to  claim 1 , wherein: 
 the cathode electrode and the anode electrode respectively constitute an upper electrode and a lower electrode;    the frequency of the high-frequency power source is within a range of 10 MHz to 30 MHz;    an area of the substrate is equal to or greater than 1 m 2 ;    a distance between the upper electrode and the lower electrode is within a range of 50 mm to 300 mm;    a processing pressure is set at a value within a range of 13 Pa to 27 Pa; and    the substrate is etched by using a process gas containing halogen.    
   
   
       29 . The plasma processing apparatus according to  claim 1 , wherein: 
 the cathode electrode and the anode electrode respectively constitute a lower electrode and an upper electrode;    the frequency of the high-frequency power source is within a range of 10 MHz to 30 MHz;    an area of the substrate is equal to or greater than 1 m 2 ;    a distance between the upper electrode and the lower electrode is within a range of 200 mm to 700 mm;    a processing pressure is set at a value within a range of 0.7 Pa to 13 Pa; and    the substrate is etched by using a process gas containing halogen.    
   
   
       30 . The plasma processing apparatus according to  claim 8 , wherein: 
 an area of the substrate is equal to or greater than 1 m 2 ;    the first high-frequency power source is connected to the upper electrode;    a distance between the upper electrode and the lower electrode is within a range of 50 mm to 300 mm;    a processing pressure is set at a value within a range of 13 Pa to 27 Pa; and    the substrate is etched by using a process gas containing halogen.    
   
   
       31 . The plasma processing apparatus according to  claim 15 , wherein: 
 an area of the substrate is equal to or greater than 1 m 2 ;    the first high-frequency power source is connected to the lower electrode;    a distance between the upper electrode and the lower electrode is within a range of 200 mm to 700 mm;    a processing pressure is set at a value within a range of 0.7 Pa to 13 Pa; and    the substrate is etched by using a process gas containing halogen.    
   
   
       32 . A plasma processing method for processing a substrate with plasma generated from a process gas by supplying high-frequency power into a processing chamber, wherein: 
 disposing a cathode electrode and an anode electrode so as to face opposite each other on an upper side and a lower side inside the processing chamber and insulating the cathode electrode and the anode electrode from the processing chamber;    connecting a high-frequency power source to one end of the cathode electrode via a matching circuit;    placing the substrate on either the cathode electrode or the anode electrode that is located on the lower side;    disposing an impedance adjustment unit containing a capacitive component with one end thereof connected to the anode electrode and another end thereof connected to the processing chamber; and    adjusting a value of impedance occurred in a path extending from the cathode electrode to a grounded casing of the matching circuit via the plasma, the anode electrode and a wall of the processing chamber to a level lower than a value of impedance occurred in a path extending from the cathode electrode to the grounded casing of the matching circuit via the plasma and the wall of the processing chamber by the impedance adjustment unit.    
   
   
       33 . A plasma processing method for processing a substrate with plasma generated from a process gas by supplying high-frequency power into a processing chamber, wherein: 
 disposing an upper electrode and a lower electrode so as to face opposite each other on an upper side and a lower side inside the processing chamber and insulating the upper electrode and the lower electrode from the processing chamber;    connecting a first high-frequency power source for supplying the high-frequency power within a range of 10 MHz to 30 MHz to one end of the upper electrode via a first matching circuit;    connecting a second high-frequency power source for supplying the high-frequency power within a range of 2 MHz to 6 MHz to one end of the lower electrode via a second matching circuit and;    placing the substrate on the lower electrode;    disposing a first impedance adjustment unit containing a capacitive component with one end thereof connected to the lower electrode and another end thereof connected to the processing chamber;    disposing a second impedance adjustment unit containing a capacitive component with one end thereof connected to the upper electrode and another end thereof connected to the processing chamber; and    adjusting a value of impedance occurred in a path extending from the upper electrode to a grounded casing of the first matching circuit via the plasma, the lower electrode and a wall of the processing chamber by the high-frequency power of the first high-frequency power source to a level lower than a value of impedance occurred in a path extending from the upper electrode to the grounded casing of the first matching circuit via the plasma and the wall of the processing chamber by the first impedance adjustment unit; and    adjusting a value of impedance occurred in a path extending from the lower electrode to a grounded casing of the second matching circuit via the plasma, the upper electrode and a wall of the processing chamber by the high-frequency power of the second high-frequency power source to a level lower than a value of impedance occurred in a path extending from the lower electrode to the grounded casing of the second matching circuit via the plasma and the wall of the processing chamber by the second impedance adjustment unit.    
   
   
       34 . A plasma processing method for processing a substrate with plasma generated from a process gas by supplying high-frequency power into a processing chamber, wherein: 
 disposing an upper electrode and a lower electrode so as to face opposite each other on an upper side and a lower side inside the processing chamber and insulating the upper electrode and the lower the electrode from the processing chamber;    connecting a first high-frequency power source for supplying the high-frequency power within a range of 10 MHz to 30 MHz to one end of the lower electrode via a first matching circuit;    connecting a second high-frequency power source for supplying the high-frequency power within a range of 2 MHz to 6 MHz to one end of the lower electrode via a second matching circuit and;    placing the substrate on the lower electrode;    disposing a first impedance adjustment unit containing a capacitive component with one end thereof connected to the upper electrode and another end thereof connected to the processing chamber;    disposing a second impedance adjustment unit containing a capacitive component with one end thereof connected to the upper electrode and another end thereof connected to the processing chamber; and    adjusting a value of impedance occurred in a path extending from the lower electrode to a grounded casing of the first matching circuit via the plasma, the upper electrode and a wall of the processing chamber by the high-frequency power of the first high-frequency power source to a level lower than a value of impedance occurred in a path extending from the lower electrode to the grounded casing of the first matching circuit via the plasma and the wall of the processing chamber by the first impedance adjustment unit; and    adjusting a value of impedance occurred in a path extending from the lower electrode to a grounded casing of the second matching circuit via the plasma, the upper electrode and a wall of the processing chamber by the high-frequency power of the second high-frequency power source to a level lower than a value of impedance occurred in a path extending from the lower electrode to the grounded casing of the second matching circuit via the plasma and the wall of the processing chamber by the second impedance adjustment unit.