Wet etchant composition and method for etching HfO2 and ZrO2

Abstract

A wet etchant solution composition and method for etching oxides of hafnium and zirconium including at least one solvent present at greater than about 50 weight percent with respect to an arbitrary volume of the wet etchant solution; at least one chelating agent present at about 0.1 weight percent to about 10 weight percent with respect to an arbitrary volume of the wet etchant solution; and, at least one halogen containing acid present from about 0.0001 weight percent to about 10 weight percent with respect to an arbitrary volume of the wet etchant solution.

1 . A wet etchant solution composition for etching oxides of hafnium and zirconium comprising: 
 at least one solvent comprising greater than about 50 weight percent with respect to an arbitrary volume of the wet etchant solution;    at least one chelating agent comprising from about 0.1 weight percent to about 10 weight percent with respect to an arbitrary volume of the wet etchant solution; and,    at least one halogen containing acid comprising from about 0.0001 weight percent to about 10 weight percent with respect to an arbitrary volume of the wet etchant solution.    
   
   
       2 . The wet etchant solution of  claim 1 , further comprising at least one surfactant comprising from about 0.1 weight percent to about 10 weight percent with respect to an arbitrary volume of the wet etchant solution.  
   
   
       3 . The wet etchant solution of  claim 1 , wherein the at least one solvent includes at least one of H 2 O, HClO 4 , an alcohol, tetrahydrofuran (THF), sulfuric acid (H 2 SO 4 ) and dimethyl sulfoxide (DMSO).  
   
   
       4 . The wet etchant solution of  claim 1 , wherein the at least one chelating agent is selected from the group consisting of diamines and beta-diketones.  
   
   
       5 . The wet etchant solution of  claim 2 , wherein the at least one surfactant is selected from the group consisting of polyols.  
   
   
       6 . The wet etchant solution of  claim 5 , wherein the surfactant comprises at least one of glycol and glycerol.  
   
   
       7 . The wet etchant solution of  claim 1 , wherein the at least one halogen containing acid includes at least one of HF, HBr, HI, and, H 3 ClO 4 .  
   
   
       8 . A method for wet etching a material layer including oxides of hafnium and zirconium in a semiconductor micro-fabrication process comprising the steps of: 
 providing a material layer comprising an oxide of at least one of hafnium and zirconium overlying a silicon dioxide containing material layer; and,    wet etching the material layer with a wet etching solution comprising at least a solvent and a halogen containing acid formed to have a first etching rate with respect to the material layer that is at least about a factor of 2.5 greater than a second etching rate with respect to the silicon dioxide containing material layer.    
   
   
       9 . The method of  claim 8 , wherein the material layer comprises at least one of hafnium dioxide (HfO 2 ) and zirconium dioxide (ZrO 2 ).  
   
   
       10 . The method of  claim 9 , wherein the solvent includes at least one of H 2 O, HClO 4 , an alcohol, tetrahydrofuran (THF), sulfuric acid (H 2 SO 4 ) and dimethyl sulfoxide (DMSO).  
   
   
       11 . The method of  claim 10 , wherein the solvent is present in the wet etchant solution at a weight percent greater than about 50 weight percent with respect to an arbitrary volume of the wet etchant solution.  
   
   
       12 . The method of  claim 9 , wherein the halogen containing acid includes at least one of HF, HBr, HI, and H 3 ClO 4 .  
   
   
       13 . The method of  claim 12 , wherein the halogen containing acid is present in the wet etchant solution from about 0.0001 weight percent to about 10 weight percent with respect to an arbitrary volume of the wet etchant solution.  
   
   
       14 . The method of  claim 9 , wherein the wet etchant solution further comprises at least one surfactant selected from the group consisting of polyols comprising from about 0.1 weight percent to about 10 weight percent with respect to an arbitrary volume of the wet etchant solution.  
   
   
       15 . The method of  claim 9 , wherein the wet etchant solution further comprises at least one chelating agent selected from the group consisting of diamines and beta-diketones comprising from about 0.1 weight percent to about 10 weight percent with respect to an arbitrary volume of the wet etchant solution.  
   
   
       16 . The method of  claim 8 , wherein the step of providing a material layer comprises providing a gate dielectric layer comprising at least one of hafnium dioxide and zirconium dioxide.  
   
   
       17 . The method of  claim 8 , wherein the step of providing a material layer comprises providing an etching stop layer comprising at least one of hafnium dioxide and zirconium dioxide.  
   
   
       18 . The method of  claim 9 , wherein the step of wet etching comprises an etching rate of the material layer of greater than about 5 Angstroms per minute.  
   
   
       19 . The method of  claim 8 , wherein the step of wet etching comprises the wet etchant solution maintained at a temperature of less than about 60° C.  
   
   
       20 . The method of  claim 8 , wherein the step of wet etching comprises at least one of immersion and spraying.