Method of removing a metal silicide layer on a gate electrode in a semiconductor manufacturing process and etching method

Abstract

A method of removing a metal suicide layer on a gate electrode in a semiconductor manufacturing process is disclosed, in which the gate electrode, a metal silicide layer, a spacer, a silicon nitride cap layer, and a dielectric layer have been formed. The method includes performing a chemical mechanical polishing process to polish the dielectric layer using the silicon nitride cap layer as a polishing stop layer to expose the silicon nitride cap layer over the gate electrode; removing the exposed silicon nitride cap layer to expose the metal silicide layer; and performing a first etching process to remove the metal silicide layer on the gate electrode.

1 . A dry etching method, comprising:
 performing a dry etching process on a metal silicide layer using an etching recipe, wherein the etching recipe comprises argon, carbon monoxide, and at least one selected from the group consisting of hydrogen gas and chlorine gas.   
   
   
       2 . The method of  claim 1 , wherein in the etching recipe, a flow rate ratio for argon: hydrogen gas: carbon monoxide is 10 to 20:20 to 30:5 to 15. 
   
   
       3 . The method of  claim 2 , wherein in the etching recipe, a flow rate ratio for argon: hydrogen gas: carbon monoxide is 15:25:10. 
   
   
       4 . The method of  claim 1 , wherein in the etching recipe, a flow rate ratio for argon: chlorine gas: carbon monoxide is 5 to 15:15 to 25:5 to 15. 
   
   
       5 . The method of  claim 4 , wherein in the etching recipe, a flow rate ratio for argon: chlorine gas: carbon monoxide is 10:20:10. 
   
   
       6 . The method of  claim 1 , wherein the metal silicide layer comprises at least one selected from the group consisting of nickel silicide and cobalt silicide.