Processing method

Abstract

A processing method which, when an organic film layer such as a PR film layer 202 formed on the surface of a wafer W is to be removed from an SiO 2 film layer 204 below it by generating plasma of a process gas in a chamber 1 comprises the step of using O 2 gas as the process gas to remove the organic film layer at a first pressure, e.g., 20 mTorr, lower than in a conventional case, and the step of using the same O 2 gas to remove the organic film layer at a second pressure, e.g., 200 mTorr, higher than the first pressure.

1 . A processing method for removing an organic film layer formed on a surface of an object to be processed by generating a plasma of a process gas in a vacuum processing vessel, comprising the step of removing the organic film layer at a pressure of equal to or lower than 100 mTorr, thereby preventing generation of crater-shaped holes at the surface of the object, 
 wherein the object has an oxide film layer on the surface thereof and the organic film layer is formed on the oxide film layer, and    wherein a NH 3  gas is used as the process gas, the process gas being essentially free of oxygen.    
   
   
       2 . The processing method of  claim 1 , wherein an overprocessing ratio of the organic film layer is set to be equal to or lower than 15% of 100% of the thickness of the organic film layer.  
   
   
       3 . The processing method of  claim 1 , wherein a portion of the vacuum processing vessel having contact with the plasma includes a metallic component.  
   
   
       4 . The processing method of  claim 3 , wherein the metallic component is yttrium.  
   
   
       5 . The processing method of  claim 3 , wherein the portion containing the metallic component is yttrium oxide.  
   
   
       6 . The processing method of  claim 1 , wherein the organic film layer is a resist layer.  
   
   
       7 . The processing method of  claim 1 , wherein the oxide film layer is a silicon oxide film layer.  
   
   
       8 . The processing method of  claim 7 , wherein the silicon oxide film layer is one of a carbon-containing silicon oxide film layer, a fluorine-containing silicon oxide film layer and a hydrogen-containing silicon oxide film layer.  
   
   
       9 . The processing method of  claim 1 , wherein one of a silicon nitride film layer, a polysilicon film layer and a metal film layer is formed beneath the silicon oxide film layer.  
   
   
       10 . A processing method for removing an organic film layer formed on a surface of an object to be processed by generating a plasma of a process gas in a vacuum processing vessel, comprising the step of removing the organic film layer at a pressure of equal to or lower than 100 mTorr, thereby preventing generation of crater-shaped holes at the surface of the object, 
 wherein the object has an oxide film layer on the surface thereof and the organic film layer is formed on the oxide film layer, and    wherein a gaseous mixture of N 2  and H 2  is used as the process gas, the process gas being essentially free of oxygen.    
   
   
       11 . The processing method of  claim 10 , wherein an overprocessing ratio of the organic film layer is set to be equal to or lower than 15% of 100% of the thickness of the organic film layer.  
   
   
       12 . The processing method of  claim 10 , wherein a portion of the vacuum processing vessel having contact with the plasma includes a metallic component.  
   
   
       13 . The processing method of  claim 12 , wherein the metallic component is yttrium.  
   
   
       14 . The processing method of  claim 12 , wherein the portion containing the metallic component is yttrium oxide.  
   
   
       15 . The processing method of  claim 10 , wherein the organic film layer Is a resist layer.  
   
   
       16 . The processing method of  claim 10 , wherein the oxide film layer is a silicon oxide film layer.  
   
   
       17 . The processing method of  claim 16 , wherein the silicon oxide film layer is one of a carbon-containing silicon oxide film layer, a fluorine-containing silicon oxide film layer and a hydrogen-containing silicon oxide film layer.  
   
   
       18 . The processing method of  claim 10 , wherein one of a silicon nitride film layer, a polysilicon film layer and a metal film layer Is formed beneath the silicon oxide film layer.