Etchant solutions and methods of forming semiconductor devices formed by processes including the same

Abstract

The present invention provides etchant solutions including deionized water and an organic acid having a carboxyl radical and a hydroxyl radical. Methods of forming magnetic memory devices are also disclosed.

1 . An etchant solution comprising: 
 deionized water; and    an organic acid having a carboxyl radical and a hydroxyl radical, wherein the etchant solution comprises about 0.05 to 50 weight percent organic acid relative to the deionized water.    
   
   
       2 . The etchant solution of  claim 1 , wherein the organic acid has an acid dissociation constant (pKa) in a range from about 2 to 4.  
   
   
       3 . The etchant solution of  claim 1 , wherein the organic acid comprises citric acid, malic acid or tartaric acid.  
   
   
       4 . The etchant solution of  claim 1 , further comprising an oxidant.  
   
   
       5 . The etchant solution of  claim 4 , wherein the oxidant has a weight percent in a range of about 0.1 to 20 relative to the deionized water.  
   
   
       6 . A method of forming a magnetic memory device, comprising: 
 forming a magnetic layer on a substrate; and    etching the magnetic layer using an etchant solution comprising deionized water and organic acid, wherein the organic acid has a carboxyl radical and a hydroxyl radical.    
   
   
       7 . The method of  claim 6 , wherein the organic acid has a weight percent in a range of about 0.05 to 35 relative to the deionized water.  
   
   
       8 . The method of  claim 7 , wherein the organic acid has an acid dissociation constant (pKa) in a range of about 2 to 4.  
   
   
       9 . The method of  claim 6 , wherein the organic acid comprises citric acid, malic acid or tartaric acid.  
   
   
       10 . The method of  claim 6 , wherein the etchant solution further comprises an oxidant.  
   
   
       11 . The method of  claim 10 , wherein the oxidant has a weight percent in a range of about 0.1 to 20 relative to the deionized water.  
   
   
       12 . The method of  claim 6 , wherein the magnetic layer comprises nickel (Ni), iron (Fe), cobalt (Co), nickel iron (Ni x Fe y ), cobalt iron (Co x Fe y ) and combinations thereof.  
   
   
       13 . A method of forming a magnetic memory device, comprising: 
 forming a bottom magnetic layer, a tunnel barrier layer and a top magnetic layer on a substrate;    forming a mask pattern on a predetermined area of the top magnetic layer; and    using an etchant solution comprising deionized water and organic acid to etch in a direction from the top magnetic layer toward a top surface of the tunnel barrier layer to form a top magnetic pattern, wherein the organic acid comprises a carboxyl radical and a hydroxyl radical.    
   
   
       14 . The method of  claim 13 , wherein the organic acid has a weight percent in a range of about 0.05 to 35 relative to the deionized water.  
   
   
       15 . The method of  claim 14 , wherein the organic acid has an acid dissociation constant (pKa) in a range of about 2 to 4.  
   
   
       16 . The method of  claim 13 , wherein the organic acid comprises citric acid, malic acid or tartaric acid.  
   
   
       17 . The method of  claim 13 , wherein the etchant solution further comprises an oxidant.  
   
   
       18 . The method of  claim 17 , wherein the oxidant has a weight percent in a range of about 0.1 to 20 relative to the deionized water.  
   
   
       19 . The method of  claim 13 , wherein the magnetic layer comprises nickel (Ni), iron (Fe), cobalt (Co), nickel iron (Ni x Fe y ), cobalt iron (Co x Fe y ) and combinations thereof.  
   
   
       20 . The method of  claim 13 , further comprising: 
 removing the mask pattern after forming the top magnetic pattern;    forming a capping insulation layer on an entire surface of the substrate; and    patterning the capping insulation layer, the tunnel barrier layer, and the bottom magnetic layer to form a bottom magnetic pattern, a tunnel barrier pattern, and a capping insulation pattern,    wherein the capping insulation pattern covers a top surface and sidewalls of the top magnetic pattern, and wherein plane areas of (a) the bottom magnetic pattern and (b) the tunnel barrier pattern are greater relative to a plane area of the top magnetic pattern.    
   
   
       21 . A method of forming a magnetic memory device, comprising: 
 forming a bottom magnetic layer, a tunnel barrier layer and a top magnetic layer on a substrate;    forming a mask pattern on a predetermined area of the top magnetic layer;    anisotropically etching the top magnetic layer, the tunnel barrier layer, and the bottom magnetic layer to form a bottom magnetic pattern, a tunnel barrier pattern, and a top magnetic pattern;    etching at least the top magnetic pattern using an etchant solution comprising deionized water and organic acid, wherein the organic acid comprises a carboxyl acid and a hydroxyl acid; and    removing the mask pattern.    
   
   
       22 . The method of  claim 21 , wherein the organic acid has a weight percent in a range of about 0.05 to 35 relative to the deionized water.  
   
   
       23 . The method of  claim 21 , wherein the organic acid has an acid dissociation constant (pKa) in a range of about 2 to 4.  
   
   
       24 . The method of  claim 21 , wherein the organic acid comprises citric acid, malic acid or tartaric acid.  
   
   
       25 . The method of  claim 21 , wherein the etchant solution further comprises an oxidant.  
   
   
       26 . The method of  claim 25 , wherein the oxidant has a weight percent in a range of about 0.1 to 20 relative to the deionized water.  
   
   
       27 . The method of  claim 21 , wherein the magnetic layer comprises nickel (Ni), iron (Fe), cobalt (Co), nickel iron (Ni x Fe y ), cobalt iron (Co x Fe y ) and combinations thereof.