Apparatus and method for plasma etching

Abstract

A plasma processing apparatus for performing plasma processing on an object to be processed, including: a processing chamber for performing plasma etching on an object to be processed; a first gas inlet provided at an upper portion of the processing chamber for supplying gas to a center portion in the processing chamber; a plurality of second gas inlets placed on an outer circumference of the first gas inlet for supplying gas to an outer circumference portion in the processing chamber; two lines of gas supply systems for supplying processing gases to the first gas inlet and the second gas inlets, respectively; an evacuation means for reducing the pressure in the processing chamber; an electrode on which the object to be processed is placed disposed in the processing chamber opposed to the first gas inlet and the second gas inlets; a high frequency power supply for generating plasma; and additional gas supply systems provided to the two lines of gas supply systems, respectively, for adding a gas for generating a depositional reaction product as additional gas via gas flow rate regulators at a given flow rate ratio.

1 . A plasma processing apparatus for performing plasma processing on an object to be processed, comprising:
 a processing chamber for performing plasma etching on an object to be processed;   a first gas inlet provided at an upper portion of the processing chamber for supplying gas to a center portion in the processing chamber;   a plurality of second gas inlets placed on an outer circumference of the first gas inlet for supplying gas to an outer circumference portion in the processing chamber;   two lines of gas supply systems for supplying processing gases to the first gas inlet and the second gas inlets, respectively;   an evacuation means for reducing the pressure in the processing chamber;   an electrode on which the object to be processed is placed disposed in the processing chamber opposed to the first gas inlet and the second gas inlets;   a high frequency power supply for generating plasma; and   additional gas supply systems provided to the two lines of gas supply systems, respectively, for adding a gas for generating a depositional reaction product as additional gas via gas flow rate regulators at a given flow rate ratio.   
   
   
       2 . The plasma processing apparatus according to  claim 1 , wherein
 the two lines of gas supply systems comprise:   a merging section where a plurality of gases from a plurality of gas supply sources are merged as first gas at a lower stream side of gas flow rate regulators provided for each gas species;   a gas shunt for dividing the first gas from the merging section into two flows at a given flow rate ratio; and   a means for adding oxygen (O 2 ) gas as second gas via gas flow rate regulators at a given flow rate ratio to the two divided flows of the first gas, respectively, so as to supply a first processing gas having the second gas added to one of the divided first gas flows to a center area in the processing chamber, and to supply a second processing gas having the second gas added to the other one of the divided first gas flows to an outer circumference area in the processing chamber.   
   
   
       3 . The plasma processing apparatus according to  claim 1 , comprising:
 an additional gas supply system for adding oxygen (O 2 ) gas as additional gas via gas flow rate regulators at a given flow rate ratio.