Aqueous indium or indium alloy plating bath and process for deposition of indium or an indium alloy

Abstract

An aqueous indium or indium alloy plating bath comprising a source of indium ions, an acid, a source of halide ions, a surfactant according to formula (I) wherein A is selected from branched or unbranched C 10 -C 15 -alkyl; B is selected from the group consisting of hydrogen and alkyl; m is an integer ranging from 5 to 25; each R is independently from each other selected from hydrogen and methyl; and a dihydroxybenzene derivative according to formula (II) wherein each X is independently selected from fluorine, chlorine, bromine, iodine, alkoxy, and nitro; n is an integer ranging from 1 to 4, wherein, when the aqueous indium or indium alloy plating bath is an indium alloy plating bath, an alloying reducible metal is selected from the group consisting of aluminum, bismuth, copper, gold, lead, nickel, silver, tin, tungsten and zinc.

1 . An aqueous indium or indium alloy plating bath comprising
 a source of indium ions,   an acid,   a source of halide ions,   a surfactant according to formula (I)   
       
         
           
           
               
               
           
         
         wherein A is selected from branched or unbranched C 10 -C 15 -alkyl; 
         B is selected from the group consisting of hydrogen and alkyl; 
         m is an integer ranging from 5 to 25; 
         each R is independently from each other selected from hydrogen and methyl; and 
         a dihydroxybenzene derivative according to formula (II) 
       
       
         
           
           
               
               
           
         
         wherein each X is independently selected from fluorine, chlorine, bromine, iodine, alkoxy, and nitro; 
         n is an integer ranging from 1 to 4, 
         wherein, when the aqueous indium or indium alloy plating bath is an indium alloy plating bath, an alloying reducible metal is selected from the group consisting of aluminum, bismuth, copper, gallium, gold, lead, nickel, silver, tin, tungsten and zinc; and 
         wherein concentration of the dihydroxybenzene derivative according to formula (II) ranges from 10-1000 mg/L. 
       
     
     
         2 . The aqueous indium or indium alloy plating bath according to  claim 1 , wherein each R is selected from hydrogen and methyl with a ratio of hydrogen/methyl of 10/1 to 100/1. 
     
     
         3 . The aqueous indium or indium alloy plating bath according to  claim 1 , wherein R is hydrogen. 
     
     
         4 . The aqueous indium or indium alloy plating bath  claim 1 , wherein the acid is selected from one or more of alkane sulfonic acid and sulfuric acid. 
     
     
         5 . The aqueous indium or indium alloy plating bath according to  claim 1 , wherein the surfactant has a value for hydrophilic-lipophilic balance (HLB value, determined according to method of Griffin) ranging from 13.0-18.0. 
     
     
         6 . The aqueous indium or indium alloy plating bath according to  claim 1 , wherein the dihydroxybenzene derivative is 4-chloro resorcinol, 5-methoxy resorcinol, chloro hydroquinone, 4-bromo resorcinol, 2-nitro resorcinol or 4-chloro catechol. 
     
     
         7 . The aqueous indium or indium alloy plating bath according to  claim 1 , having a pH of −1 to 4. 
     
     
         8 . The aqueous indium or indium alloy plating bath according to  claim 1 , further comprising a source of alkali metal cations and/or a source of alkaline earth metal cations. 
     
     
         9 . The aqueous indium or indium alloy plating bath according to  claim 1 , wherein concentration of indium ions in the indium or indium alloy plating bath ranges from 2.5 g/L to 200 g/L. 
     
     
         10 . The aqueous indium or indium alloy plating bath according to  claim 1 , wherein concentration of the surfactant according to formula (I) ranges from 0.1 g/L to 20 g/L. 
     
     
         11 . The aqueous indium or indium alloy plating bath according to  claim 1 , wherein the surfactant has a value for hydrophilic-lipophilic balance (HLB value, determined according to method of Griffin) ranging from 13.0-18.0; wherein the dihydroxybenzene derivative is 4-chloro resorcinol, 5-methoxy resorcinol, chloro hydroquinone, 4-bromo resorcinol, 2-nitro resorcinol or 4-chloro catechol; wherein the aqueous indium or indium alloy plating bath has a pH of −1 to 4; wherein the bath further comprises a source of alkali metal cations and/or a source of alkaline earth metal cations; wherein concentration of indium ions in the indium or indium alloy plating bath ranges from 2.5 g/L to 200 g/L; and wherein concentration of the surfactant according to formula (I) ranges from 0.1 g/L to 20 g/L. 
     
     
         12 . The aqueous indium or indium alloy plating bath according to  claim 11 , wherein each R is selected from hydrogen and methyl with a ratio of hydrogen/methyl of 10/1 to 100/1. 
     
     
         13 . The aqueous indium or indium alloy plating bath according to  claim 11 , wherein R is hydrogen. 
     
     
         14 . The aqueous indium or indium alloy plating bath according to  claim 1 , wherein the bath is an indium alloy bath. 
     
     
         15 . The aqueous indium or indium alloy plating bath according to  claim 11 , wherein the bath is an indium alloy bath. 
     
     
         16 . The aqueous indium or indium alloy plating bath according to  claim 1 , wherein when present, the alloying reducible metal is present in the bath in amounts sufficient to form an indium alloy having 1 wt.-% to 5 wt.-% of the alloying metal. 
     
     
         17 . The aqueous indium or indium alloy plating bath according to  claim 11 , wherein when present, the alloying reducible metal is present in the bath in amounts sufficient to form an indium alloy having 1 wt.-% to 5 wt.-% of the alloying metal.