Alkaline composition for copper electroplating comprising a grain refiner

Abstract

Described herein is a composition for depositing copper on a semiconductor substrate, the composition including(a) copper ions;(b) a grain refiner of formula G1a or G1bor salts thereof;(c) a complexing agent; and(d) optionally a buffer or a base to adjust the pH to a pH of from 7 to 13;whereinRG1 is selected from one or more H, C1 to C4 carboxyl, C1 to C4 alkyl, C1 to C6 alkoxy, halogen, and CN;RG2 is selected from one or more H, C1 to C4 carboxyl, C1 to C4 alkyl, C1 to C6 alkoxy, halogen, and CN; andXG1 is selected from C1 to 6 alkanediyl or a group —XG11—C(O)—O—XG12—;XG11 is selected from a chemical bond or C1 to C4 alkandiyl;XG12 is selected from a chemical bond or C1 to C4 alkandiyl; andwherein RG1 or RG2, comprises at least one C1 to C4 carboxyl group, or group XG1 is —XG11—C(O)—O—)—XG12—;wherein the pH of the composition is from 7 to 13.

1 . A composition for depositing copper on a semiconductor substrate, the composition consisting essentially of:
 (a) a source of copper ions;   (b) a grain refiner of formula G1a or G1b   
       
         
           
           
               
               
           
         
       
       or salts thereof;
 (c) a complexing agent; and 
 (d) optionally a buffer or a base to adjust the pH to a pH of from 7 to 13; 
 (e) optionally a defect reducing agent of formula S1; 
 
       
         
           
           
               
               
           
         
         (f) optionally a non-ionic surfactant; and 
         (g) water, 
       
       wherein
 R G1  is selected from the group consisting of one or more H, C 1  to C 4  carboxyl, C 1  to C 4  alkyl, C 1  to C 6  alkoxy, halogen, and CN; 
 R G2  is selected from the group consisting of one or more H, C 1  to C 4  carboxyl, C 1  to C 4  alkyl, C 1  to C 6  alkoxy, halogen, and CN; and 
 X G1  is selected from the group consisting of C 1  to C 6  alkanediyl and —X G11 —C(O)—O—X G12 —; 
 X G11  is selected from the group consisting of a chemical bond and C 1  to C 4  alkandiyl; 
 X G12  is selected from the group consisting of a chemical bond and C 1  to C 4  alkandiyl; and
 wherein R G1  or R G2  comprises at least one C 1  to C 4  carboxyl group, or group X G1  is —X G11 —C(O)—O—)—X G12 —; and 
 
 wherein the pH of the composition is from 7 to 13. 
 
     
     
         2 . The composition according to  claim 1 , wherein
 R G1  is selected from the group consisting of one or more H, C 1  to C 4  carboxyl, C 1  to C 4  alkyl, C 1  to C 6  alkoxy, halogen, and CN;   R G2  is selected from the group consisting of one or more H, C 1  to C 4  carboxyl, C 1  to C 4  alkyl, C 1  to C 6  alkoxy, halogen, H and CN; and   X G1  is a C 1  to C 4  alkanediyl;   
       and wherein R G1  or R G2  comprises at least one C 1  to C 4  carboxyl group. 
     
     
         3 . The composition according to  claim 1 , wherein the grain refiner is a compound of formula G2a, G2b, or salts thereof 
       
         
           
           
               
               
           
         
       
       wherein
 R G21  is selected from the group consisting of one or more H, C 1  to C 3  alkyl, C 1  to C 4  alkoxy, halogen, and CN; 
 R G22  is selected from the group consisting of one or more H, C 1  to C 4  alkyl, C 1  to C 6  alkoxy, halogen, and CN; and 
 X G1  is methandiyl, ethanediyl, propanediyl or butanediyl. 
 
     
     
         4 . The composition according to  claim 3 , wherein the grain refiner is 3-carboxy-1-phenylmethylpyridinium. 
     
     
         5 . The composition according to  claim 1 , wherein
 R G1  is selected from the group consisting of one or more H, C 1  to C 4  carboxyl, C 1  to C 4  alkyl, C 1  to C 6  alkoxy, halogen, and CN;   R G2  is selected from the group consisting of one or more H, C 1  to C 4  carboxyl, C 1  to C 4  alkyl, C 1  to C 6  alkoxy, halogen, and CN; and   X G1  is a group —X G11 —C(O)—O—)—X G12 —;   X G11 , X G12  are independently selected from the group consisting of C 1  to C 4  alkandiyl.   
     
     
         6 . The composition according to  claim 1 , wherein the grain refiners are compounds of formula G3a, G3b, G3c, or salts thereof 
       
         
           
           
               
               
           
         
       
       wherein
 R G31  is selected from the group consisting of one or more H, C 1  to C 4  carboxyl, C 1  to C 4  alkyl, C 1  to C 6  alkoxy, halogen, and CN; 
 R G32  is selected from the group consisting of one or more H, C 1  to C 4  carboxyl, C 1  to C 4  alkyl, C 1  to C 6  alkoxy, C 1  to C 6  carboxy, halogen, and CN; and 
 X G32  is selected from the group consisting of a chemical bond and C 1  to C 4  alkandiyl. 
 
     
     
         7 . The composition according to  claim 6 , wherein the grain refiners are 4-(Methoxycarbonyl)benzyl pyridine-3-carboxylate and benzyl pyridine-3-carboxylate. 
     
     
         8 . The composition according to  anyone of the preceding claims   claim 1 , further comprising a defect reducing agent of formula S1 
       
         
           
           
               
               
           
         
       
       or salts thereof, 
       wherein
 R S1  is selected from the group consisting of X S —Y S , 
 R S2  is selected from the group consisting of R S1  and R S3 . 
 X S  is selected from the group consisting of linear or branched C 1  to C 10  alkanediyl, linear or branched C 2  to C 10  alkenediyl, linear or branched C 2  to C 10  alkynediyl, and —X S6 —(O—C 2 H 3 R S6 ) m —; 
 Y S  is selected from the group consisting of OR S3 , NR S3 R S4 , N + R S3 R S4 R S5  and NH—(C═O)—R S3 ; 
 R S3 , R S4 , R S5  are the same or different and are selected from the group consisting of (i) H, (ii) C 5  to C 20  aryl, (iii) C 1  to C 10  alkyl (iv) C 6  to C 20  arylalkyl, (v) C 6  to C 20  alkylaryl, which may be substituted by OH, SO 3 H, COOH or a combination thereof, and 
 (vi) —(C 2 H 3 R S6 —O) n —R S6 , and wherein R S3  and R S4  may together form a ring system, which may be interrupted by O or NR S7 , 
 X S6  is C 1  to C 6  alkanediyl; 
 m, n are integers independently selected from the group consisting of 1 to 30; 
 R S6  is selected from the group consisting of H and C 1  to C 5  alkyl; 
 
       
         
           
           
               
               
           
         
       
     
     
         9 . (canceled) 
     
     
         10 . The composition according to anyone of the preceding claims  claim 1 , which has a pH of 8 to 12. 
     
     
         11 . (canceled) 
     
     
         12 . (canceled) 
     
     
         13 . The composition according to  claim 1 , wherein the buffer or base is a hydroxide. 
     
     
         14 . (canceled) 
     
     
         15 . A method of using a composition, the method comprising using the composition for depositing copper on a semiconductor substrate comprising recessed features having an aperture size 50 nanometers or less,
 the composition comprising:
 (a) copper ions; 
 (b) a grain refiner of formula G1a or G1b 
   
       
         
           
           
               
               
           
         
       
       or salts thereof;
 (c) a complexing agent; and 
 (d) optionally a buffer or a base to adjust the pH to a pH of from 7 to 13; 
 
       wherein
 R G1  is selected from the group consisting of one or more H, C 1  to C 4  carboxyl, C 1  to C 4  alkyl, C 1  to C 6  alkoxy, halogen, and CN; 
 R G2  is selected from the group consisting of one or more H, C 1  to C 4  carboxyl, C 1  to C 4  alkyl, C 1  to C 6  alkoxy, halogen, and CN; and 
 X G1  is selected from the group consisting of C 1  to Co alkanediyl and —X G11 —C(O)—O—X G12 —; 
 X G11  is selected from the group consisting of a chemical bond and C 1  to C 4  alkandiyl; 
 X G12  is selected from the group consisting of a chemical bond and C 1  to C 4  alkandiyl; and
 wherein R G1  or R G2  comprises at least one C 1  to C 4  carboxyl group, or group X G1  is—X G11 —C(O)—O—)—X G12 —; and 
 
 wherein the pH of the composition is from 7 to 13. 
 
     
     
         16 . The use according to  claim 15 , wherein the recessed features have an aspect ratio of 4 or more. 
     
     
         17 . The method of use according to  claim 15 , wherein the semiconductor substrate is a dielectric substrate onto which a conducting seed layer is placed, wherein the seed layer consists of cobalt, iridium, osmium, palladium, platinum, rhodium, ruthenium, molybdenum, or alloys thereof. 
     
     
         18 . A process for depositing copper on a semiconductor substrate comprising a recessed feature having an aperture size of 50 nm or less, preferably 15 nm or less, the recessed feature comprising a metal seed, the process comprising
 (a) bringing a composition into contact with the metal seed, and   (b) applying a current for a time sufficient to deposit a continuous seed of copper onto the metal seed of the recessed feature or to completely fill the recessed feature;   
       wherein the composition comprises:
 (a) copper ions; 
 (b) a grain refiner of formula G1a or G1b 
 
       
         
           
           
               
               
           
         
         or salts thereof; 
         (c) a complexing agent; and 
         (d) optionally a buffer or a base to adjust the pH to a pH of from 7 to 13; 
         wherein 
         R G1  is selected from the group consisting of one or more H, C 1  to C 4  carboxyl, C 1  to C 4  alkyl, C 1  to C 6  alkoxy, halogen, and CN; 
         R G2  is selected from the group consisting of one or more H, C 1  to C 4  carboxyl, C 1  to C 4  alkyl, C 1  to C 6  alkoxy, halogen, and CN; and 
         X G1  is selected from the group consisting of C 1  to Co alkanediyl and —X G11 —C(O)—O—X G12 —; 
         X G11  is selected from the group consisting of a chemical bond and C 1  to C 4  alkandiyl; 
         X G12  is selected from the group consisting of a chemical bond and C 1  to C 4  alkandiyl; and
 wherein R G1  or R G2  comprises at least one C 1  to C 4  carboxyl group, or group X G1  is —X G11 —C(O)—O—)—X G12 —; and 
 
         wherein the pH of the composition is from 7 to 13. 
       
     
     
         19 . The process according to  claim 18 , wherein the seed layer consists of cobalt, iridium, osmium, palladium, platinum, rhodium, ruthenium, molybdenum, or alloys thereof. 
     
     
         20 . The process according to  claim 18 , wherein the seed consists of cobalt. 
     
     
         21 . The process according to  claim 18 , wherein the seed consists of ruthenium. 
     
     
         22 . The process according to  claim 18 , wherein the recessed feature is completely filled with copper. 
     
     
         23 . The process according to  claim 18 , wherein a continuous seed of copper is deposited onto the metal seed of the recessed feature.