Method for removing photoresist layer

Abstract

A method described for removing a photoresist/polymers layer on a substrate. The method comprises the steps of providing a wafer having an oxide layer, a photoresist/polymers layer, an opening penetrating through the photoresist/polymers layer and the oxide layer, and the sidewall polymer on the surface of photoresist layer and the oxide layer. An in-situ plasma-etching step using an additional gas mixed with oxygen as source is performed to remove the photoresist/polymers layer without residues, no damages to substrate and oxide and no changes on the critical dimension of the opening during etching step.

What is claimed is:  
     
         1 . A method for removing photoresist on a wafer having an oxide layer, a photoresist/polymers layer, an opening penetrating through the photoresist/polymers layer and the oxide layer, the method comprising the steps of: 
 performing an in-situ plasma etching step using an additional gas mixed with oxygen as a source to remove the photoresist/polymers layer.    
     
     
         2 . The method of    claim 1   , wherein the additional gas is selected from the group consisting of N 2 , hydrogen( H 2 )-containing gas and the combination thereof.  
     
     
         3 . The method of    claim 2   , wherein when the additional gas is N 2 , the ratio of N 2  to the O 2 /N 2  mixing gas is about 1%-50%.  
     
     
         4 . The method of    claim 2   , wherein when the additional gas is the hydrogen-containing gas, the ratio of hydrogen-containing gas to the O 2 /hydrogen-containing mixing gas is about 1%-30%.  
     
     
         5 . The method of    claim 4   , wherein the hydrogen-containing gas is selected from a group consisting of CH 2 F 2 , CH 3 F, C 2 H 2 F 4 , C 3 H 2 F 6  and the combinations thereof.  
     
     
         6 . The method of    claim 2   , wherein when the additional gas is the combination of N 2  and hydrogen-containing gas, the ratios of hydrogen containing gases and N 2 to the O 2 /N 2 /hydrogen-containing mixing gas are respectively about 1%-30% and 1%-50%.  
     
     
         7 . The method of    claim 6   , wherein the hydrogen-containing gas is selected from a group consisting of CH 2 F 2 , CH 3 F, C 2 H 2 F 4 , C 3 H 2 F 6  and the combinations thereof.  
     
     
         8 . The method of    claim 1   , wherein the step of removing the photoresist/polymers layer is performed under the conditions of: 
 a flux of about 100-3000 sccm for the mixing gas;    a pressure of about 20 millitorr to 1 torr for the mixing gas;    a power of about 1000 to 3000 W for the in-situ plasma etching step;    a bias power on a wafer of about 0 to 300 W for the in-situ plasma etching step;    a wafer temperature of about −20 to 400 centigrade for removing the photoresist/polymers layer; and    a pressure of about 1 to 100 torr for the helium background gas.