Plasma processing apparatus having an evacuating arrangement to evacuate gas from a gas-introducing part of a process chamber

Abstract

A plasma processing apparatus can apply a high-quality process to an object to be processed by removing impurities from a gas-introducing part of a process chamber. The gas-introducing part connected to the process chamber so as to introduce a reactant gas into the process chamber. A first vacuum pump is connected to the process chamber so as to evacuate gas from the process chamber so that the process chamber is maintained at a negative pressure. A gas-evacuating arrangement is connected to the gas-introducing part so as to exclusively evacuate the reactant gas from the gas-introducing part. The gas-evacuating arrangement includes a second vacuum pump directly connected to the gas introducing part or a bypass passage connecting the gas-introducing par to the first vacuum pump by bypassing the process chamber.

What is claimed is:  
     
         1 . A plasma processing apparatus for applying a plasma process to an object to be processed, the plasma processing apparatus comprising: 
 a process chamber in which the object to be processed is subjected to the plasma process;    a gas-introducing part connected to said process chamber so as to introduce a reactant gas into said process chamber;    a first vacuum pump connected to said process chamber so as to evacuate gas from said process chamber so that said process chamber is maintained at a negative pressure; and    a gas-evacuating arrangement connected to said gas-introducing part so as to evacuate the reactant gas from said gas-introducing part.    
     
     
         2 . The plasma processing apparatus as claimed in  claim 1 , wherein said gas-evacuating arrangement comprises a second vacuum pump connected to said gas-introducing part.  
     
     
         3 . The plasma processing apparatus as claimed in  claim 1 , wherein said gas-evacuating arrangement comprises a bypass passage which connects said gas-introducing part to said first vacuum pump by bypassing said process chamber.  
     
     
         4 . The plasma processing apparatus as claimed in  claim 1 , wherein said gas-introducing part has an annular shape and is incorporated into a sidewall of said process chamber, said gas-introducing part has a plurality of circumferentially arranged nozzles through which the reactant gas is introduced into said process chamber.  
     
     
         5 . The plasma processing apparatus as claimed in  claim 4 , wherein said gas-introducing part comprises: 
 at least one inlet port from which the reactant gas is supplied;    an annular gas passage connected to said inlet port so that the reactant gas supplied from the inlet port is supplied to said plurality of nozzles by flowing through said annular gas passage; and    an outlet port provided to said annular gas passage so that said gas-evacuating arrangement is connected thereto.    
     
     
         6 . The plasma processing apparatus as claimed in  claim 1 , wherein said gas-introducing part comprises a dielectric plate and a shower plate provided on a top of said process chamber so as to introduce the reactant gas from the top of said process chamber, a gas passage being formed between said dielectric plate and said shower plate so that the reactant gas flows through the gas passage and is introduced into said process chamber through said shower plate.  
     
     
         7 . The plasma processing apparatus as claimed in  claim 6 , wherein dielectric plate has an inlet port connected to said gas passage so as to supply the reactant gas to said gas passage, and said gas passage has an outlet port to which said gas-evacuating arrangement is connected.  
     
     
         8 . The plasma processing apparatus as claimed in  claim 1 , further comprising a slot antenna having a plurality of slits so as to guide a microwave having a predetermined frequency which is determined by the plasma process to be applied to the object to be processed.  
     
     
         9 . The plasma processing apparatus as claimed in  claim 8 , wherein a density of the slits is substantially uniform in a radial direction of said slot antenna.  
     
     
         10 . A gas supply ring adapted to introduce a reactant gas into a process chamber of a processing apparatus, the gas supply ring comprising: 
 a plurality of circumferentially arranged nozzles through which the reactant gas is introduced into said process chamber;    at least one inlet port from which the reactant gas is supplied;    an annular gas passage connected to said inlet port so that the reactant gas supplied from the inlet port is supplied to said plurality of nozzles by flowing through said annular gas passage; and    an outlet port provided to said annular gas passage so that the reactant gas is evacuated from said gas supply ring through said outlet port.    
     
     
         11 . A dielectric plate adapted to be attached to a process chamber of a plasma processing apparatus, the dielectric plate comprising: 
 a plurality of nozzles through which a reactant gas is introduced into said process chamber;    at least one inlet port from which the reactant gas is supplied;    a gas passage connected to said inlet port so that the reactant gas supplied from the inlet port is supplied to said plurality of nozzles by flowing through said gas passage; and    an outlet port provided to said gas passage so that the reactant gas is evacuated from said gas passage through said outlet port.    
     
     
         12 . A plasma processing method comprising the steps of: 
 evacuating gas from a process chamber by a first vacuum pump connected to said process chamber;    introducing a reactant gas into said process chamber through a gas-introducing part;    applying a plasma process to an object placed in said process chamber by generating plasma from the reactant gas;    stopping the introduction of the reactant gas into said process chamber after ending the plasma process; and    evacuating the reactant gas remaining in said gas-introducing part by a second vacuum pump connected to said gas-introducing part.    
     
     
         13 . A plasma processing method comprising the steps of: 
 evecuating gas from a process chamber by a vacuum pump connected to said process chamber;    introducing a reactant gas into said process chamber through a gas-introducing part having a plurality of nozzles;    applying a plasma process to an object placed in said process chamber by generating plasma from the reactant gas;    stopping the introduction of the reactant gas into said process chamber after ending the plasma process; and    evacuating the reactant gas remaining in said gas-introducing part by said vacuum pump by connecting said gas-introducing part to said vacuum pump by bypassing said process chamber.