Etching method of multilayer film

Abstract

A plasma processing apparatus for performing a plasma process on a substrate includes: a mounting table configured to mount thereon the substrate; an electromagnet including a core member and a plurality of coils; a current source connected to both ends of the coils for supplying currents to the coils; and a control unit configured to control the current source to start or stop and to control a current value of the current source. The core member is made of a magnetic material and has a structure including a column-shaped member, multiple cylindrical members, and a base member. The plurality of coils are accommodated in grooves and wound around an outer peripheral surface of the column-shaped member and the cylindrical members, and the grooves are formed between the column-shaped member and one of the cylindrical members and between the cylindrical members.

1 . (canceled) 
     
     
         2 . A plasma processing apparatus for performing a plasma process on a substrate in a processing chamber, the apparatus comprising:
 a mounting table configured to mount thereon the substrate;   an electromagnet comprising:
 a core member made of a magnetic material and having a structure including a column-shaped member, multiple cylindrical members, and a base member,
 wherein the column-shaped member is provided such that a central axis line thereof coincides with a substrate central axis line vertically passing through a center of the substrate, 
 wherein each of the multiple cylindrical members is extended in a direction of the substrate central axis line, and is arranged on each of multiple concentric circles around the substrate central axis line, 
 wherein at least one of the cylindrical members is positioned outside of an edge of the substrate in a radial direction, and 
 wherein the base member has a substantially disc shape and is provided such that a central axis line thereof coincides with the substrate central axis line; and 
 
 a plurality of coils accommodated in grooves and wound around an outer peripheral surface of the column-shaped member and the cylindrical members,
 wherein the grooves are formed between the column-shaped member and one of the cylindrical members and between the cylindrical members; 
 
   a current source connected to both ends of the coils for supplying currents to the coils; and   a control unit configured to control the current source to start or stop and to control a current value of the current source.   
     
     
         3 . The plasma processing apparatus of  claim 2 , wherein the control unit is further configured to control the current source to start or stop for each film of a multilayer film including a first oxide film, a second oxide film, and an organic film formed between the first oxide film and the second oxide film. 
     
     
         4 . The plasma processing apparatus of  claim 3 , further comprising:
 a high frequency power supply for plasma generation configured to apply a high frequency power to one of an upper electrode and the mounting table serving as a lower electrode.   
     
     
         5 . The plasma processing apparatus of  claim 4 , wherein the high frequency power supply for plasma generation is further configured to apply the high frequency power in an etching of the organic film that is set to be higher than the high frequency power in an etching of the first oxide film and the high frequency power in an etching of the second oxide film. 
     
     
         6 . The plasma processing apparatus of  claim 2 , further comprising:
 a high frequency power supply for ion attraction configured to apply a high frequency bias power to the mounting table serving as a lower electrode.   
     
     
         7 . The plasma processing apparatus of  claim 6 , wherein the high frequency power supply for ion attraction is further configured to apply the high frequency bias power in an etching of the first oxide film and the high frequency bias power in an etching of the second oxide film that are set to be higher than the high frequency bias power in an etching of the organic film. 
     
     
         8 . The plasma processing apparatus of  claim 7 , wherein the control unit is further configured to generate a magnetic field such that horizontal magnetic field components in the radial direction with respect to the substrate central axis line have an intensity distribution having a peak value at a position far from the substrate central axis line by controlling the current source. 
     
     
         9 . The plasma processing apparatus of  claim 8 , wherein the control unit is further configured to generate a magnetic field such that a position of the peak value of the horizontal magnetic field components in the etching of the organic film is closer to the substrate central axis line than a position of the peak value of the horizontal magnetic field components in the etching of the first oxide film and a position of the peak value of the horizontal magnetic field components in the etching of the second oxide film. 
     
     
         10 . The plasma processing apparatus of  claim 9 , wherein the high frequency power supply is further configured to apply the high frequency bias power in the etching of the second film that is set to be higher than the high frequency power in the etching of a first oxide film, and
 the control unit is further configured to generate the magnetic field such that intensity of the horizontal magnetic field components in the etching of the second oxide film is higher than intensity of the horizontal magnetic field components in the etching of the first oxide film when a thickness of the second oxide film is greater than a thickness of the first oxide film.   
     
     
         11 . The plasma processing apparatus of  claim 9 , the control unit is further configured to generate the magnetic field such that, in the etching of the organic film, a position of a peak intensity of the horizontal magnetic field components is an intermediate position between a center of the substrate and an edge of the substrate in the radial direction. 
     
     
         12 . The plasma processing apparatus of  claim 9 , the control unit is further configured to generate the magnetic field such that, in the etching of the first oxide film and the etching of the second oxide film, a position of a peak intensity of the horizontal magnetic field components is an outer position of an edge of the substrate in the radial direction 
     
     
         13 . The plasma processing apparatus of  claim 2 , wherein the control unit is further configured to control the current source to start or stop for each film of a multilayer film including a first oxide film and a second oxide film. 
     
     
         14 . The plasma processing apparatus of  claim 13 , further comprising:
 a high frequency power supply for plasma generation configured to apply a high frequency power to one of an upper electrode and the mounting table serving as a lower electrode.   
     
     
         15 . The plasma processing apparatus of  claim 14 , wherein the high frequency power supply for plasma generation is further configured to apply the high frequency power in an etching of the second film that is set to be higher than the high frequency power in an etching of the first oxide film. 
     
     
         16 . The plasma processing apparatus of  claim 13 , further comprising:
 a high frequency power supply for ion attraction configured to apply a high frequency bias power to the mounting table serving as a lower electrode.   
     
     
         17 . The plasma processing apparatus of  claim 16 , wherein the high frequency power supply for ion attraction is further configured to apply the high frequency bias power in an etching of the first oxide film that is set to be higher than the high frequency bias power in an etching of the second oxide film. 
     
     
         18 . The plasma processing apparatus of  claim 17 , wherein the control unit is further configured to generate a magnetic field such that horizontal magnetic field components in the radial direction with respect to the substrate central axis line have an intensity distribution having a peak value at a position far from the substrate central axis line by controlling the current source, and
 wherein the control unit is further configured to generate a magnetic field such that a position of the peak value of the horizontal magnetic field components in the etching of the second oxide film is closer to the substrate central axis line than a position of the peak value of the horizontal magnetic field components in the etching of the first oxide film.   
     
     
         19 . The plasma processing apparatus of  claim 18 , wherein the control unit is further configured to generate a magnetic field such that, in the etching of the second film, a position of a peak intensity of the horizontal magnetic field components is an intermediate position between a center of the substrate and an edge of the substrate in the radial direction. 
     
     
         20 . The plasma processing apparatus of  claim 18 , wherein the control unit is further configured to generate a magnetic field such that, in the etching of the first film, a position of a peak intensity of the horizontal magnetic field components is an outer position of an edge of the substrate in the radial direction.