Plating bath and method

Abstract

This invention relates to copper plating baths containing a leveling agent that is a reaction product of one or more of certain cyclodiaza-compounds with one or more epoxide-containing compounds useful to deposit copper on the surface of a conductive layer. Such plating baths deposit a copper layer that is substantially planar on a substrate surface across a range of electrolyte concentrations. This invention also relates to methods of depositing copper layers using such copper plating baths.

What is claimed is: 
     
         1 . A copper electroplating bath comprising: a source of copper ions, an electrolyte, and a leveling agent, wherein the leveling agent is a reaction product of one or more cyclodiaza-compounds with one or more epoxide-containing compounds; wherein at least one of the cyclodiaza-compounds has the formulae (IIIa) or (IIIb) 
       
         
           
           
               
               
           
         
       
       wherein R 1  and R 2  are independently chosen from H, (C 1 -C 6 )alkyl and (C 6 -C 10 )aryl; R 4  and R 5  to R 10  are independently chosen from H, (C 1 -C 6 )alkyl, (C 6 -C 10 )aryl and hydroxyl; each of R 1  and R 2 , R 5  and R 7 , R 7  and R 9 , and R 9  and R 1  may be taken together to form a chemical bond; and any of R 1  and R 5  to R 10  on adjacent ring atoms may be taken together along with the atoms to which they are attached to form a 5- or 6-membered saturated or unsaturated ring 
     
     
         2 . The copper electroplating bath of  claim 1  wherein the epoxide-containing compound comprises from 1 to 3 epoxy groups. 
     
     
         3 . The copper electroplating bath of  claim 2  wherein the epoxide-containing compound is chosen from compounds of the formulae 
       
         
           
           
               
               
           
         
       
       where Y, Y 1  and Y 2  are independently chosen from H and (C 1 -C 4 )alkyl; each Y 3  is independently chosen from H, an epoxy group, and (C 1 -C 6 )alkyl; X=CH 2 X 2  or (C 2 -C 6 )alkenyl; X 1 =H or (C 1 -C 5 )alkyl; X 2 =halogen, O(C 1 -C 3 )alkyl or O(C 1 -C 3 )haloalkyl; A=OR 11  or R 12 ; R 11 =((CR 13 R 14 ) m O) n , (aryl-O) p , CR 13 R 14 —Z—CR 13 R 14 O or OZ 1   t O; R 12 =(CH 2 ) y ; Al is a (C 5 -C 12 )cycloalkyl ring or a 5- to 6-membered cyclicsulfone ring; Z=a 5- or 6-membered ring; Z 1  is R 15 OArOR 15 , (R 16 O) a Ar(OR 16 ) a , or (R 16 O) a Cy(OR 16 ) a ; Z 2 =SO 2  or 
       
         
           
           
               
               
           
         
       
       Cy=(C 5 -C 12 )cycloalkyl; each R 13  and R 14  are independently chosen from H, CH 3  and OH; each R 15  represents (C 1 -C 8 )alkyl; each R 16  represents a (C 2 -C 6 )alkyleneoxy; each a=1-10; m=1-6; n=1-20; p=1-6; q=1-6; r=0-4; t=1-4; v=0-3; and y=0-6; wherein Y 1  and Y 2  may be taken together to form a (C 8 -C 12 )cyclic compound. 
     
     
         4 . The copper electroplating bath of  claim 1  further comprising an accelerator. 
     
     
         5 . The copper electroplating bath of  claim 1  wherein the at least one cyclodiaza-compound is selected from the group consisting of pyridazine, 3-methylpyridazine, 4-methylpyridazine, 3,6-dihydroxypyridazine, 3,6-dihydroxy-4-methyl-pyridazine, phthalazine, 6-phenyl-3(2H)-pyridazinone, 6-(2-hydroxyphenyl)-3(2H)-pyridazinone, 4,5-dihydro-6-phenyl-3(2H)-pyridazinone, 1(2H)-phthalazinone, 4-phenylphthalazin-1(2H)-one, 4-(4-methylphenyl)phthalazin-1(2H)-one, and 4-(4-chlorophenyl)phthalazin-1(2H)-one. 
     
     
         6 . The copper electroplating bath of  claim 1  further comprising a suppressor.