Composition for tin or tin alloy electroplating comprising leveling agent

Abstract

Described herein is an aqueous composition including tin ions, optionally alloy metal ions selected from the group consisting of silver, copper, indium, and bismuth ions and at least one additive of formula L1

1 . An aqueous composition comprising tin ions, optionally alloy metal ions selected from the group consisting of silver, copper, indium, and bismuth ions, and at least one additive of formula L1 
       
         
           
           
               
               
           
         
         wherein 
         R L1  is, for each group R L1  independently, selected from the group consisting of C 1  to C 6  alkyl, C 1  to C 6  alkenyl, C 1  to C 6  alkoxy, halogen, CN, and OH; 
         R L2  is selected from the group consisting of C 1  to C 6  alkyl, C 1  to C 6  alkenyl, C 5  to C 12  aryl, C 6  to C 15  alkylaryl, and C 6  to C 15  arylalkyl, all of which may be substituted by CN, OH, C 1  to C 6  alkoxy or halogen; 
         R L3  is selected from the group consisting of C 1  to C 6  alkyl; 
         R L4  is H; 
         n is the number of substituents R L1  selected from the group consisting of 0 to 5, 
         wherein the amount of organic solvents in the composition is below 0.1 g/l, and 
         wherein the composition does not contain any electrolytically depositable metal ions besides tin ions and the alloying metal ions. 
       
     
     
         2 . The composition according to  claim 1 , wherein R L3  is selected from the group consisting of C 1  to C 4  alkyl. 
     
     
         3 . The composition according to  claim 2 , wherein R L3  is methyl. 
     
     
         4 . The composition according to  claim 1 , wherein n is 0. 
     
     
         5 . The composition according to  claim 1 , wherein n is 1 or 2 and R L1   n , for each group R L1  independently, selected from the group consisting of C 1  to C 4  alkyl and C 1  to C 4  alkoxy. 
     
     
         6 . The composition according to  claim 1 , wherein R L2  is selected from the group consisting of methyl, ethyl, 1-propyl, and 2-propyl. 
     
     
         7 . The composition according to  claim 1 , wherein the tin ions are present in an amount of from 40 to 120 g/l. 
     
     
         8 . The composition according to  claim 1 , wherein the alloy metal ions are present in an amount of from 0.2 to 3% by weight. 
     
     
         9 . The composition according to  claim 8 , wherein the alloy metal ions comprise silver ions. 
     
     
         10 . The composition according to  claim 1 , wherein the pH of the composition is below 4. 
     
     
         11 . A method of using an additive of formula L1 
       
         
           
           
               
               
           
         
         in a composition, the method comprising using the additive for electrodepositing tin or tin alloy containing layers, wherein the tin alloy containing layers comprise an alloy metal selected from the group consisting of silver, copper, indium, and bismuth in an amount of 0.01 to 10% by weight, 
         wherein 
         R L1  is, for each group R L1  independently, selected from the group consisting of C 1  to C 6  alkyl, C 1  to C 6  alkenyl, C 1  to C 6  alkoxy, halogen, CN, and OH; 
         R L2  is selected from the group consisting of C 1  to C 6  alkyl, C 1  to C 6  alkenyl, C 5  to C 12  aryl, C 6  to C 15  alkylaryl, and C 6  to C 15  arylalkyl, all of which may be substituted by CN, OH, C 1  to C 6  alkoxy or halogen; 
         R L3  is selected from the group consisting of C 1  to C 6  alkyl; 
         R L4  is H; 
         n is the number of substituents R U  selected from the group consisting of 0 to 5, 
         wherein the amount of organic solvents in the composition is below 0.1 g/l, and 
         wherein the composition does not contain any electrolytically depositable metal ions besides tin ions and the alloying metal ions. 
       
     
     
         12 . The method according to  claim 11 , wherein the deposited tin alloy layer has an alloy metal content of 0.1 to 5% by weight. 
     
     
         13 . A process for depositing a tin or tin alloy layer onto a substrate by
 a) contacting a tin alloy electroplating bath comprising a composition according to  claim 1  with the substrate, and   b) applying a current density to the substrate for a time sufficient to deposit the tin or tin alloy layer onto the substrate.   
     
     
         14 . The process according to  claim 13 , wherein the substrate comprises recessed features having an aperture size from 1 to 1000 micrometers, and the deposition is performed to at least partially fill the micrometer sized recessed features. 
     
     
         15 . A compound selected from the group consisting of (E)-4-ethyl-5-(4-methylphenyl)-pent-4-en-3-one and (E)-4-ethyl-5-(4-methoxyphenyl)-pent-4-en-3-one. 
     
     
         16 . The composition according to  claim 1 , wherein R L2  is selected from the group consisting of methyl and ethyl. 
     
     
         17 . The composition according to  claim 1 , wherein the tin ions are present in an amount from 60 to 90 g/l. 
     
     
         18 . The composition according to  claim 1 , wherein the alloy metal ions are present in an amount of from 0.3 to 2.0% by weight. 
     
     
         19 . The composition according to  claim 8 , wherein the alloy metal ions consist of silver ions. 
     
     
         20 . The composition according to  claim 1 , wherein the pH of the composition is below 3.