Etching composition and method for manufacturing a capacitor using the same

Abstract

An etching composition for preventing from leaning a capacitor contains hydrofluoric acid (HF), ammonium fluoride (NH 4 F), an alkyl ammonium fluoride (R e NH 3 F; where R e is a C 1 -C 10 linear or branched alkyl radical), a surfactant, an alcohol compound, and water. The composition can effectively suppress the leaning phenomenon of capacitors during the formation of the capacitors, so that height of the storage node of the capacitor can be secured, capacitors with improved capacitance can be manufactured, and the process can be adapted to the production of both present and future devices.

1 . An etching composition for preventing from leaning a capacitor, the composition comprising: hydrofluoric acid (HF), ammonium fluoride (NH 4 F), an alkyl ammonium fluoride (R e NH 3 F), a surfactant, an alcohol compound, and water, wherein R e  is a C 1 -C 10  linear or branched alkyl radical. 
     
     
         2 . The etching composition of  claim 1 , further comprising one or more acid compounds selected from the group consisting of sulfuric acid, phosphoric acid, nitric acid, formic acid, and acetic acid. 
     
     
         3 . The etching composition of  claim 1 , wherein the hydrofluoric acid (HF) is present in an amount ranging from 0.1 weight part to 5 weight parts based on 100 weight parts of the etching composition. 
     
     
         4 . The etching composition of  claim 1 , wherein the ammonium fluoride (NH 4 F) is present in an amount ranging from 1 weight part to 40 weight parts based on 100 weight parts of the etching composition. 
     
     
         5 . The etching composition of  claim 1 , wherein the alkyl ammonium fluoride (R e NH 3 F) is present in an amount ranging from 1 weight part to 40 weight parts based on 100 weight parts of the etching composition. 
     
     
         6 . The etching composition of  claim 1 , wherein the surfactant is present in an amount ranging from 100 ppm to 10000 ppm based the weight of the etching composition. 
     
     
         7 . The etching composition of  claim 1 , wherein the alcohol compound is present in an amount ranging from 1 weight part to 80 weight parts based on 100 weight parts of the etching composition. 
     
     
         8 . The etching composition of  claim 1 , wherein the water is present in an amount ranging from 20 weight part to 80 weight parts based on 100 weight parts of the etching composition. 
     
     
         9 . The etching composition of  claim 1 , wherein the surfactant is selected from the group consisting of non-ionic surfactants, cationic surfactants, anionic surfactants, and mixtures thereof. 
     
     
         10 . The etching composition of  claim 1 , wherein the surfactant comprises a compound according to Formula 1 below: 
       
         
           
           
               
               
           
         
         wherein: R is a C 8 -C 20  alkyl radical or a C 6 -C 20  aromatic ring; 
         x, y, and z are independently integers ranging from 0 to 10; 
         n is an integer ranging from  3  to  50 ; and, 
         the average molecular weight of the compound according to Formula 1 ranges from 1,000 to 10,000. 
       
     
     
         11 . The etching composition of  claim 1 , wherein the surfactant comprises a compound according to Formula 2 below: 
       
         
           
           
               
               
           
         
         wherein: m is an integer ranging from 3 to 50; and, 
         the average molecular weight of the compound according to Formula 1 ranges from 1,000 to 10,000. 
       
     
     
         12 . The etching composition of  claim 1 , wherein the composition has surface tension ranging from 16 dyn/cm to 50 dyn/cm at a temperature of23° C. 
     
     
         13 . The etching composition of  claim 12 , wherein the composition has surface tension ranging from 16 dyn/cm to 25 dyn/cm at a temperature of 23° C. 
     
     
         14 . A method of manufacturing a capacitor, comprising the steps of:
 forming a barrier film and a capacitor oxide film over a semiconductor substrate having an interlayer insulating film containing storage node contact plugs;   forming a trench by etching the capacitor oxide film and the barrier film thereby exposing the storage node contact plugs and a peripheral portion of the interlayer insulating film;   forming a lower electrode used for a storage node inside the trench, thereby covering the capacitor oxide film;   forming an isolated lower electrode by removing a portion of the lower electrode until the capacitor oxide film is exposed;   removing the capacitor oxide film with the etching composition of  claim 1 ;   rinsing the resultant structure with an alcohol; and, drying the resultant structure.   
     
     
         15 . The method of  claim 14 , wherein the capacitor oxide film is a phosphor silica glass (PSG) or a plasma enhanced tetraethyl ortho silica (PE-TEOS). 
     
     
         16 . The method of  claim 14 , wherein the step of isolating the lower electrode comprises performing a chemical mechanical polishing process or an etch back process. 
     
     
         17 . The method of  claim 14 , wherein the step of rinsing the resultant structure comprises immersing the resultant structure in an alcohol solution or placing the resultant structure in an alcohol vapor. 
     
     
         18 . The method of  claim 14 , wherein the step of drying the resultant structure comprises drying in air at a temperature ranging from 10° C. to 70° C. 
     
     
         19 . A semiconductor device manufactured according to the method of  claim 14 .