Pre-ECD wet surface modification to improve wettability and reduce void defect

Abstract

A pre-ECD wet surface treatment. After forming the barrier material ( 110 ) and seed layer ( 112 ), the surface of the seed layer ( 112 ) is treated with a water-based solution to remove surface contamination ( 122 ) and improve wettability. The ECD copper film ( 124 ) is then formed over the seed layer ( 112 ).

In the claims:  
     
         1 . A method of fabricating an integrated circuit, comprising the steps of: 
 forming a seed layer over a semiconductor body;    performing a wet surface treatment on said seed layer; and    after performing said wet surface treatment, depositing a copper layer on said seed layer using electrochemical deposition (ECD).    
     
     
         2 . The method of  claim 1 , wherein said step of performing a wet surface treatment occurs in a plating cell of an ECD tool.  
     
     
         3 . The method of  claim 2 , wherein said step of performing a wet surface treatment comprises the step of rinsing said seed layer with a water-based solution for a duration in the range of 1-5 seconds.  
     
     
         4 . The method of  claim 1 , wherein said step of performing a wet surface treatment occurs in a cell separate from a plating cell of an ECD tool.  
     
     
         5 . The method of  claim 4 , wherein said step of performing a wet surface treatment comprises the step of rinsing said seed layer with a water-based solution for a duration in the range of 1-15 seconds.  
     
     
         6 . The method of  claim 1 , wherein said step of performing a wet surface treatment occurs in a tool separate from an ECD tool used to deposit said copper layer.  
     
     
         7 . The method of  claim 6 , wherein said step of performing a wet surface treatment comprises the step of rinsing said seed layer with a water-based solution for a duration in the range of 1-15 seconds.  
     
     
         8 . The method of  claim 1 , wherein said step of performing a wet surface treatment comprises the step of rinsing said seed layer with an aqueous solution.  
     
     
         9 . The method of  claim 8 , wherein the step of performing a wet surface treatment further comprises the step of spin-drying said seed layer after said rinsing step.  
     
     
         10 . The method of  claim 8 , wherein the step of performing a wet surface treatment further comprises the step of drying said seed layer with N 2 .  
     
     
         11 . The method of  claim 8 , wherein said aqueous solution comprises de-ionized water.  
     
     
         12 . The method of  claim 8 , wherein said aqueous solution comprises a solution selected from the group consisting of isopropyl alcohol and de-ionized (DI)-water, acetone and DI-water, methyl alcohol and DI-water, ethyl alcohol and DI-water, and acetic acid and DI-water.  
     
     
         13 . A method of fabricating a copper interconnect for an integrated circuit comprising the steps of: 
 providing a semiconductor body having a dielectric layer with a trench formed therein;    forming a barrier layer over said dielectric layer including within said trench;    forming a seed layer over said barrier layer;    rinsing said seed layer with a water-based solution;    after said rinsing step, electrochemically depositing a copper layer on said seed layer; and    chemically-mechanically polishing said copper layer to form said copper interconnect in said trench.    
     
     
         14 . The method of  claim 13 , wherein said rinsing step occurs in a plating cell of an ECD tool and has a duration in the range of 1-5 seconds.  
     
     
         15 . The method of  claim 13 , wherein said rinsing step occurs in a cell separate from a plating cell of an ECD tool and has a duration in the range of 1-15 seconds.  
     
     
         16 . The method of  claim 13 , wherein said rinsing step occurs in a tool separate from an ECD tool used to deposit said copper layer and has a duration in the range of 1-15 seconds.  
     
     
         17 . The method of  claim 13  further comprising the step of spin-drying said seed layer after said rinsing step.  
     
     
         18 . The method of  claim 13 , wherein said water-based solution comprises de-ionized water.  
     
     
         19 . The method of  claim 13 , further comprising the step of drying said seed layer with N 2  after said rinsing step.  
     
     
         20 . The method of  claim 13 , wherein said water-based solution is selected from the group consisting of isopropyl alcohol and de-ionized (DI) water, acetone and DI-water, methyl alcohol and DI-water, ethyl alcohol and DI-water, and acetic acid and DI-water.