Electroplating bath

Abstract

Copper electroplating baths containing one or more suppressor compounds capable of providing copper filled sub-micron sized apertures free of pits and voids are provided. Such copper electroplating baths are useful in the manufacture of electronic devices, such as printed wiring boards and integrated circuits.

What is claimed is:  
     
         1 . A composition comprising one or more sources of copper ions, an electrolyte and one or more poly(alkylene oxide) random copolymers comprising as polymerized units two or more alkylene oxide monomers.  
     
     
         2 . The composition of  claim 1  wherein the poly(alkylene oxide) random copolymer is an ethylene oxide /propylene oxide random copolymer.  
     
     
         3 . The composition of  claim 2  wherein the ethylene oxide/propylene oxide random copolymer has the formula HO—(A) n —(B) m —H wherein each of A and B are selected from ethyleneoxy and propyleneoxy groups provided that A and B are different; and n and m are the number of A and B repeat units, respectively, in the copolymer.  
     
     
         4 . The composition of  claim 1  wherein the poly(alkylene oxide) random copolymer is a linear copolymer or a star copolymer.  
     
     
         5 . The composition of  claim 1  wherein the poly(alkylene oxide) random copolymer has a molecular weight of 500 to 20,000.  
     
     
         6 . The composition of  claim 1  further comprising one or more brighteners.  
     
     
         7 . The composition of  claim 1  further comprising one or more leveling agents.  
     
     
         8 . The composition of  claim 1  wherein the electrolyte is acidic.  
     
     
         9 . A method of depositing a layer of copper on a substrate comprising the steps of contacting the substrate with the composition of  claim 1  and applying current density for a period of time sufficient to deposit a layer of copper on the substrate.  
     
     
         10 . The method of  claim 9  wherein the substrate is a printed wiring board, lead frame or an integrated circuit.  
     
     
         11 . The method of  claim 9  wherein the poly(alkylene oxide) random copolymer is an ethylene oxide/propylene oxide random copolymer.  
     
     
         12 . The method of  claim 11  wherein the ethylene oxide /propylene oxide random copolymer has the formula HO—(A) n —(B) m —H wherein each of A and B are selected from ethyleneoxy and propyleneoxy groups provided that A and B are different; and n and m are the number of A and B repeat units, respectively, in the copolymer.  
     
     
         13 . The method of  claim 9  wherein the substrate has one or more apertures having a width of ≦1 μm.  
     
     
         14 . A method of manufacturing an electronic device comprising the step of depositing a layer of copper on an electronic device comprising the steps of contacting the electronic device substrate with the composition of  claim 1  and applying current density for a period of time sufficient to deposit a layer of copper on the electronic device.  
     
     
         15 . The method of  claim 14  wherein the substrate is a printed wiring board, lead frame or an integrated circuit.  
     
     
         16 . The method of  claim 14  wherein the poly(alkylene oxide) random copolymer is an ethylene oxide/propylene oxide random copolymer.  
     
     
         17 . The method of  claim 16  wherein the ethylene oxide /propylene oxide random copolymer has the formula HO—(A) n —(B) m —H wherein each of A and B are selected from ethyleneoxy and propyleneoxy groups provided that A and B are different; and n and m are the number of A and B repeat units, respectively, in the copolymer.  
     
     
         18 . The method of  claim 14  wherein the substrate has one or more apertures having a width of ≦1 μm.