Application of antifoaming agent to reduce defects in a semiconductor electrochemical plating process

Abstract

Embodiments of the invention provide a method and formulations for preventing foam formation inside a plating apparatus prior to or during plating a material on a substrate. In one embodiment, a method for preventing foam formation inside a plating apparatus designed for plating a material on a substrate includes providing an electrolyte solution containing at least one antifoaming agent, at least one metal ion source, and a supporting electrolyte. The method further includes placing the substrate onto a substrate holder of the plating apparatus, immersing the substrate in the electrolyte solution, and depositing the material onto the substrate.

What is claimed is:  
     
         1 . A method for preventing foam formation inside a plating cell, comprising: 
 providing an electrolyte solution to the cell, the electrolyte solution containing an antifoaming agent, a metal ion source, and a supporting electrolyte;    placing the substrate onto a substrate holder of the plating apparatus;    immersing the substrate in the electrolyte solution; and    depositing the material onto the substrate.    
     
     
         2 . The method of  claim 1 , further comprising connecting electrical power to a plurality of electrical contacts disposed to contact the surface of the substrate after the substrate is placed onto the substrate holder.  
     
     
         3 . The method of  claim 1 , further comprising monitoring foam formation inside the plating apparatus and dosing the antifoaming agent into the electrolyte solution in accordance with a measured foam thickness.  
     
     
         4 . The method of  claim 1 , wherein the metal ion source is copper.  
     
     
         5 . The method of  claim 1 , wherein the antifoaming agent is selected from the group consisting of alcohols, monohydric alcohols, polyhydric alcohols, octyl alcohol, C 6  to C 20  alcohols, lauryl alcohol, and combinations and derivatives thereof.  
     
     
         6 . The method of  claim 1 , wherein the antifoaming agent is dissolved in ethanol.  
     
     
         7 . The method of  claim 1 , wherein the antifoaming agent is 1-octanol dissolved in ethanol.  
     
     
         8 . The method of  claim 1 , wherein the antifoaming agent is at a final concentration of between about 0.002% and about 10% by volume in the electrolyte solution.  
     
     
         9 . The method of  claim 1 , wherein one metal ion source comprises a metal salt selected from the group consisting of copper salt, noble metal salt, semi-noble metal salt, and combinations thereof.  
     
     
         10 . The method of  claim 1 , wherein the supporting electrolyte comprise acid and water.  
     
     
         11 . A method for preventing foam formation inside an electroless plating apparatus, comprising: 
 providing an electroless plating solution containing at least one antifoaming agent;    immersing the substrate in the electroless plating solution; and    depositing a material layer onto the substrate by electroless deposition in the electroless plating solution.    
     
     
         12 . The method of  claim 11 , wherein the material layer comprises a catalytic seed layer.  
     
     
         13 . The method of  claim 12 , further comprising depositing a conductive layer on the substrate over the catalytic seed layer.  
     
     
         14 . The method of  claim 11 , wherein the material layer comprises a conductive layer.  
     
     
         15 . The method of  claim 11 , wherein the at least one antifoaming agent is selected from the group consisting of alcohols, monohydric alcohols, polyhydric alcohols octyl alcohol, C 6  to C 20  alcohols, lauryl alcohol, hydrophobic oils, amines, alkyl amines, diamyl methyl amine, amides, acyl derivatives of piperazine, alkaline earth, sodium stearate, aluminum stearate, hydrophobic compounds, hydrophobic silica, and combinations and derivatives thereof.  
     
     
         16 . The method of  claim 11 , wherein the at least one antifoaming agent is at a final concentration of between about 0.002% and about 10% by volume in the plating electrolyte solution.  
     
     
         17 . A method for preventing foam formation inside an electroless plating apparatus designed for electroless plating on a substrate, comprising: 
 providing a catalytic layer solution containing at least one antifoaming agent;    immersing the substrate in the catalytic layer solution;    depositing a catalytic seed layer onto the substrate by electroless deposition in the catalytic layer solution; and    depositing a conductive layer on the substrate over the catalytic seed layer.    
     
     
         18 . The method of  claim 17 , wherein the conductive layer is deposited by a deposition technique selected from the group consisting of physical vapor deposition, chemical vapor deposition, electrochemical plating, electroless plating, and combinations thereof.  
     
     
         19 . A method for preventing foam formation inside a plating apparatus designed for plating on a substrate having a metal seed layer formed thereon, comprising: 
 providing an electrolyte solution containing at least one antifoaming agent;    immersing the substrate in the electrolyte solution; and    depositing a conductive layer onto the metal seed layer of the substrate.    
     
     
         20 . The method of  claim 19 , further comprising monitoring foam formation inside the plating apparatus and dosing the antifoaming agent into the electrolyte solution.  
     
     
         21 . The method of  claim 19 , wherein the at least one antifoaming agent is selected from the group consisting of alcohols, monohydric alcohols, polyhydric alcohols octyl alcohol, C 6  to C 20  alcohols, lauryl alcohol, hydrophobic oils, amines, alkyl amines, diamyl methyl amine, amides, acyl derivatives of piperazine, alkaline earth, sodium stearate, aluminum stearate, hydrophobic compounds, hydrophobic silica, and combinations and derivatives thereof.  
     
     
         22 . The method of  claim 19 , wherein the at least one antifoaming agent is dissolved in at least one solvent selected from the group consisting of alcohols, ethanol, siloxanes, polydimethyl siloxane, and combinations and derivatives thereof, before adding to the electrolyte solution.  
     
     
         23 . The method of  claim 19 , wherein the at least one antifoaming agent is at a final concentration of between about 0.002% and about 10% by volume in the electrolyte solution.  
     
     
         24 . A composition for a plating bath, comprising: 
 at least one antifoaming agent selected from the group consisting of alcohols, monohydric alcohols, polyhydric alcohols octyl alcohol, C6 to C20 alcohols, lauryl alcohol, and combinations and derivatives thereof;    a metal ion source; and    a supporting electrolyte.    
     
     
         25 . The composition of  claim 24 , wherein the at least one antifoaming agent is first dissolved in at least one solvent selected from the group consisting of alcohols, ethanol, siloxanes, polydimethyl siloxane, and combinations and derivatives thereof.  
     
     
         26 . The composition of  claim 24 , wherein the at least one antifoaming agent is 1-octanol dissolved in ethanol.  
     
     
         27 . The composition of  claim 24 , wherein the at least one antifoaming agent is at a final concentration of between about 0.002% and about 10% by volume.  
     
     
         28 . The composition of  claim 24 , wherein the at least one metal ion source comprise a metal salt selected from the group consisting of copper salt, noble metal salt, semi-noble metal salt, and combinations thereof.