Surfactants for post-chemical mechanical polishing storage and cleaning

Abstract

Methods and compositions are disclosed for chemical mechanical polishing (CMP) of semiconductor substrates, post-CMP storage of semiconductor substrates and post-CMP cleaning of semiconductor substrates. The methods and compositions feature the use of surfactants and, in some cases, passivation agents. The methods and compositions are particularly suited to polishing, storing and cleaning semiconductor substrates comprising hydrophobic surfaces.

What is claimed is:  
     
         1 . A method for storage of a semiconductor substrate comprising immersing the semiconductor substrate in a liquid comprising water and a surfactant.  
     
     
         2 . The method of  claim 1  wherein the storage occurs following a CMP process but prior to an associated post-CMP cleaning process.  
     
     
         3 . The method of  claim 2  wherein a surface of the semiconductor substrate comprises silica.  
     
     
         4 . The method of  claim 2  wherein a surface of the semiconductor substrate comprises copper.  
     
     
         5 . The method of  claim 4  wherein the liquid further comprises a passivation agent selected from the group consisting of benzotriazole, hydroquinone, pyrogallol, gallic acid and combinations thereof.  
     
     
         6 . The method of  claim 5  wherein the passivation agent is benzotriazole.  
     
     
         7 . The method of  claim 2  wherein a least a portion of a surface of the semiconductor substrate is hydrophobic.  
     
     
         8 . The method of  claim 2  wherein the surfactant is an anionic surfactant.  
     
     
         9 . The method of  claim 2  wherein the surfactant is an cationic surfactant.  
     
     
         10 . The method of  claim 2  wherein the surfactant is an nonionic surfactant.  
     
     
         11 . The method of  claim 2  wherein the surfactant is Coppeready® Post Clean Surfactant.  
     
     
         12 . The method of  claim 2  wherein the concentration of surfactant in the liquid is between about 0.01 and about 10 weight percent.  
     
     
         13 . A post-CMP storage liquid comprising: 
 a. water;    b. a surfactant; and    c. a passivation agent.    
     
     
         14 . The post-CMP storage liquid of  claim 13  wherein the passivation agent comprises a material selected from the group consisting of benzotriazole, hydroquinone, pyrogallol, gallic acid and combinations thereof.  
     
     
         15 . The post-CMP storage liquid of  claim 14  wherein the surfactant is present at a concentration in the liquid of between about 0.01 and about 10 weight percent.  
     
     
         16 . A method for removing contaminants from a surface material of a semiconductor substrate comprising: 
 a. placing the semiconductor substrate that has been subjected to a chemical mechanical polishing operation in a cleaning apparatus; and    b. cleaning the surface material on the semiconductor substrate in a liquid comprising water, a passivation agent, and a surfactant.    
     
     
         17 . The method of  claim 16  wherein the cleaning further comprises an application of a mechanical force.  
     
     
         18 . The method of  claim 17  wherein the mechanical force is applied with a scrub brush.  
     
     
         19 . The method of  claim 17  wherein the mechanical force is applied using sonic or ultrasonic energy.  
     
     
         20 . The method of  claim 19  wherein the passivation agent comprises a material selected from the group consisting of benzotriazole, hydroquinone, pyrogallol, gallic acid and combinations thereof.  
     
     
         21 . The method of  claim 19  wherein the passivation agent comprises benzotriazole.  
     
     
         22 . The method of  claim 19  wherein the liquid further comprises a basic component such that the liquid possesses a pH greater than about 8.  
     
     
         23 . The method of  claim 22  the basic component is a tetravalent ammonium compound.  
     
     
         24 . The method of  claim 23  wherein the tetravalent ammonium compound is tetramethylammonium hydroxide.  
     
     
         25 . The method of  claim 19  wherein the liquid further comprises an acidic component such that the liquid possesses a pH less than about 6.  
     
     
         26 . The method of  claim 25  wherein the acidic component is an organic acid.  
     
     
         27 . The method of  claim 26  wherein the organic acid is citric acid.  
     
     
         28 . The method of  claim 19  wherein the surface material of the semiconductor substrate comprises a material selected from the group consisting of copper and silica.  
     
     
         29 . A post-CMP cleaning liquid comprising: 
 a. water;    b. a surfactant; and    c. a passivation agent.    
     
     
         30 . The post-CMP cleaning liquid of  claim 29  wherein the passivation agent comprises a material selected from the group consisting of benzotriazole, hydroquinone, pyrogallol, gallic acid and combinations thereof.