Etching method

Abstract

In an etching method, multiple etchings are sequentially performed in a single processing vessel on a laminated film having a plurality of layers formed on a substrate to be processed, without unloading the substrate to be processed from the vessel. Between the etchings, a cleaning processing for removing deposits from the processing vessel by using a plasma of a cleaning gas is performed. The cleaning gas is O 2 containing gas, and preferably, a gaseous mixture of O 2 and N 2 gas. Further, the cleaning processing is performed under conditions of 50˜200 mTorr in the processing vessel; 5˜15 mL/min of O 2 flow rate; and 100˜400 mL/min of N 2 flow rate. The method prevents etching characteristics from being affected due to a memory effect, while offering the advantages of an all-in-one etching.

1 . An etching method for sequentially performing multiple etchings in a single processing vessel on a laminated film having a plurality of layers formed on a substrate to be processed, without unloading the substrate to be processed from the vessel, 
 wherein, between the etchings, a cleaning processing for removing deposits from the processing vessel by using a plasma of a cleaning gas is performed.    
   
   
       2 . An etching method for sequentially performing multiple etchings in a single processing vessel on a laminated film having a plurality of layers formed on a substrate to be processed in an order of a first film and a second film from a top, without unloading the substrate to be processed from the vessel, the method comprising the steps of: 
 performing a first etching of the first film by using a plasma of a first etching gas;    performing a cleaning processing for removing deposits from the processing vessel by using plasma of a cleaning gas after the first etching; and    performing a second etching of the second film by using a plasma of a second etching gas after the cleaning.    
   
   
       3 . The etching method of  claim 2 , wherein, in the first etching, a silicon oxide film as the first film is etched by using the plasma of the first etching gas containing CF based gas; and 
 in the second etching, a silicon nitride film as the second film is etched by using the plasma of the second etching gas containing CHF based gas.    
   
   
       4 . The etching method of  claim 2 , wherein, in the first etching, a silicon oxide film as the first film is etched by using the plasma of the first etching gas containing CF based gas; and 
 in the second etching, an organic film as the second film is etched by using the plasma of the second etching gas containing N 2  or NH 3  gas.    
   
   
       5 . The etching method of  claim 2 , wherein, in the second etching, the first film serves as a mask film.  
   
   
       6 . The etching method of  claim 1  or  2 , wherein the cleaning processing is performed without applying a bias power to the substrate to be processed.  
   
   
       7 . The etching method of  claim 1  or  2 , wherein the cleaning gas is O 2  containing gas.  
   
   
       8 . The etching method of  claim 7 , wherein the O 2  containing gas is a gaseous mixture of O 2  and N 2  gas.  
   
   
       9 . The etching method of  claim 8 , wherein the cleaning processing is performed under conditions of 50˜200 mTorr in the processing vessel; 5˜15 mL/min of O 2  flow rate; and 100˜400 mL/min of N 2  flow rate.  
   
   
       10 . An etching method for sequentially performing multiple etchings by using a patterned mask film as a mask in a single processing vessel on a laminated film having a plurality of layers formed on a substrate to be processed in an order of a first insulating film and a second insulating film from a top, without unloading the substrate to be processed from the vessel, the method comprising the steps of: 
 performing a first etching of the first insulating film by using a plasma of a first etching gas;    performing a cleaning processing for removing deposits from the processing vessel by using a plasma of a cleaning gas after the first etching; and    performing a second etching of the second insulating film by using a plasma of a second etching gas after the cleaning,    wherein, in the first and the second etchings, bias powers are applied to the substrate to be processed; and, in the cleaning processing, a bias power is not applied to the substrate to be processed.    
   
   
       11 . The etching method of  claim 10 , wherein, in the first etching, a silicon oxide film as the first insulating film is etched by using the plasma of the first etching gas containing CF based gas; and 
 in the second etching processing, a silicon nitride film as the second insulating film is etched by using the plasma of the second etching gas containing CHF based gas.    
   
   
       12 . The etching method of  claim 10 , wherein, in the first etching, a silicon oxide film as the first insulating film is etched by using the plasma of the first etching gas containing CF based gas; and 
 in the second etching, an organic film as the second insulating film is etched by using the plasma of the second etching gas containing N 2  or NH 3  gas.    
   
   
       13 . The etching method of  claim 10 , wherein the cleaning gas is O 2  containing gas.  
   
   
       14 . The etching method of  claim 13 , wherein the O 2  containing gas is a gaseous mixture of O 2  and N 2  gas.  
   
   
       15 . The etching method of  claim 14 , wherein the cleaning processing is performed under conditions of 50˜200 mTorr in the processing vessel; 5˜15 mL/min of O 2  flow rate; and 100˜400 mL/min of N 2  flow rate.