Composition for Cobalt Electroplating Comprising Leveling Agent

Abstract

Described herein is a cobalt electrodeposition composition including cobalt ions, and particular leveling agents including X1—CO—O—R11, X1—SO2—O—R11, X1—PO(OR11)2, X1—SO—O—R11 functional groups, whereX1 is a divalent group selected from (i) a chemical bond (ii) aryl, (iii) C1 to C12 alkandiyl, which may be interrupted by O atoms, (iv) an arylalkyl group —X11—X12—, (v) an alkylaryl group —X12—X11— and (vi) —(O—C2H3R12)mO—,R11 is selected from H and C1 to C4 alkyl.R12 is selected from H and C1 to C4 alkyl,X12 is a divalent aryl group, andX11 is a divalent C1 to C15 alkandiyl group.

1 - 16 . (canceled) 
     
     
         17 . A composition, comprising:
 (a) metal ions consisting essentially of cobalt ions, and   (b) a leveling agent,   wherein the leveling agent is a compound of formula L2:   
       
         
           
           
               
               
           
         
         or a compound of formula L4:
   Ø-R 1    (L4),
 
 
         or salts thereof, 
         wherein 
         R 1  is selected from the group consisting of X 1 —CO—O—R 11 , X 1 —SO 2 —O—R 11 , X 1 —PO(OR 11 ) 2 , and X 1 —SO—O—R 11 ; 
         R 2 , R 3 , R 4  are independently selected from the group consisting of R 1  and (i) H, (ii) aryl, (iii) C 1  to C 10  alkyl (iv) arylalkyl, (v) alkylaryl, and (vi) —(O—C 2 H 3 R 12 ) m —OH, wherein if one of R 2 , R 3  or R 4  is R 1 , remaining R 2 , R 3  or R 4  are different from R 1 , 
         Ø is a C 6  to C 14  carbocyclic or a C 3  to C 10  nitrogen or oxygen containing heterocyclic aryl group, which is optionally unsubstituted or substituted by up to three C 1  to C 12  alkyl groups or up to two OH, NH 2  or NO 2  groups, 
         X 1  is a divalent group selected from the group consisting of (i) a chemical bond (ii) aryl, (iii) C 1  to C 12  alkandiyl, which is optionally interrupted by O atoms, (iv) arylalkyl group —X 11 —X 12 —, (v) alkylaryl group —X 12 —X 11 —, and (vi) —(O—C 2 H 3 R 12 ) m O—, 
         R 11  is selected from the group consisting of H and C 1  to C 4  alkyl, 
         R 12  is selected from the group consisting of H and C 1  to C 4  alkyl, 
         X 11  is a divalent C 1  to C 15  alkandiyl group, 
         X 12  is a divalent aryl group, and 
         m is an integer from 2 to 50,
 wherein the composition is essentially free of any dispersed particles. 
 
       
     
     
         18 . The composition according to  claim 17 , wherein R 2 , R 3  and R 4  are selected from the group consisting of H, methyl, ethyl, and propyl. 
     
     
         19 . The composition according to  claim 17 , wherein R 2  and either R 3  or R 4  are selected from the group consisting of H, methyl, ethyl, and propyl, and remaining R 3  or R 4  is R 1 . 
     
     
         20 . The composition according to  claim 17 , wherein R 3  and R 4  are selected from the group consisting of H, methyl, ethyl, and propyl, and R 2  is R 1 . 
     
     
         21 . The composition according to  claim 17 , wherein the leveling agent is a compound of formula L4a: 
       
         
           
           
               
               
           
         
         wherein R 5 , R 6 , R 7 , R 8 , and R 9  are independently selected from the group consisting of (i) H and (ii) C 1  to C 6  alkyl. 
       
     
     
         22 . The composition according to  claim 17 , wherein R 11  is H. 
     
     
         23 . The composition according to  claim 17 , wherein m is an integer from 2 to 30. 
     
     
         24 . The composition according to  claim 17 , wherein the leveling agent is itaconic acid. 
     
     
         25 . The composition according to  claim 17 , wherein the leveling agent is selected from the group consisting of acrylic acid, itaconic acid, vinylphosphonic acid, and vinylsulfonic acid. 
     
     
         26 . The composition according to  claim 17 , wherein R 1  is a sulphonate group. 
     
     
         27 . The composition according to  claim 17 , wherein the leveling agent is p-toluol sulfonate. 
     
     
         28 . The composition according to  claim 17 , wherein the composition further comprises a suppressing agent selected from the group consisting of a hydroxy alkyne or an amino alkyne. 
     
     
         29 . A process for depositing cobalt on a semiconductor substrate comprising a recessed feature having an aperture size below 100 nm, the process comprising
 (a) bringing a composition according to  claim 17  into contact with the semiconductor substrate,   (b) applying an electrical potential for a time sufficient to fill the recessed feature with cobalt.   
     
     
         30 . A process according to  claim 29 , comprising: depositing a cobalt seed on a dielectric surface of the recessed feature before the bringing. 
     
     
         31 . A process according to  claim 29 , wherein the recessed feature has an aperture size of 30 nm or below.