Plating bath and method for depositing a metal layer on a substrate

Abstract

A metal plating bath and method for plating a metal on a substrate. The metal plating bath contains hydroxylamines that inhibit the consumption of additive bath components to improve the efficiency of metal plating processes. The additive bath components are added to metal plating baths to improve brightness of plated metal as well as the micro-throwing and macro-throwing power of the bath. In addition to brighteners, the additive bath components may include levelers, suppressors, hardeners, and the like. The hydroxylamines that inhibit additive consumption may be employed in metal plating baths for plating copper, gold, silver, platinum, palladium, cobalt, cadmium, nickel, bismuth, indium, tin, rhodium, iridium, ruthenium and alloys thereof.

What is claimed is:  
     
         1 . A metal plating bath comprising an additive consumption inhibiting compound having a formula:  
       (R 1 —NHR 2 —OH) n X  
       where R 1  and R 2  are each independently hydrogen, C 1 -C 6  alkyl, n is 1 or 2, when n is 1, X is HSO 4   − , H 2 PO 4   − , NO 3   − , F − , Cl − , Br −  or I −  and when n is 2, X is SO 4   2− ; and metal salts of copper, gold, silver, palladium, platinum, cobalt, cadmium, chromium, nickel, bismuth, indium, tin, rhodium, lead, ruthenium, iridium, or alloys thereof.  
     
     
         2 . The metal plating bath of  claim 1 , wherein the C 1 -C 6  alkyl comprises methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, isohexyl, 3-methylpentyl, 2,2-dimethylbutyl, or 2,3-dimethylbutyl.  
     
     
         3 . The metal plating bath of  claim 1 , wherein the additive consumption inhibiting compound comprises hydroxylamine sulfate, hydroxylamine nitrate, hydroxylamine chloride or mixtures thereof.  
     
     
         4 . The metal plating bath of  claim 1 , wherein the additive consumption inhibiting compound comprises from about 0.001 g/L to about 100 g/L of the bath.  
     
     
         5 . The metal plating bath of  claim 4 , wherein the additive consumption inhibiting compound comprises from about 0.01 g/L to about 20.0 g/L of the bath.  
     
     
         6 . The metal plating bath of  claim 1 , further comprising additives comprising brighteners, levelers, hardeners, wetting agents, malleability modifiers, ductility modifiers, deposition modifiers, or suppressors.  
     
     
         7 . The metal plating bath of  claim 6 , wherein the brighteners comprise compounds having the formulas: HO 3 —S—R 11 —SH; HO 3 S—R 11 —S—S—R 11 —SO 3 H, where R 11  is C 1 -C 6  alky or an aryl group; or HO 3 —Ar—S—S—Ar—SO 3 H, where Ar is phenyl or naphthyl, the alky and aryl groups may be unsubstituted or substituted with an alkyl group, halo or alkoxy group.  
     
     
         8 . The metal plating bath of  claim 7 , wherein the brighteners comprise 3-mercapto-propylsulfonic acid sodium salt, 2-mercapto-ethanesulfonic acid sodium salt, bissulfopropyl disulfide, N,N-dimethyldithiocarbamic acid (3-sulfopropyl) ester sodium salt, (O-ethyldithiocarbonato)-S-(3-sulfopropyl)-ester potassium salt, 3-[(amino-iminomethyl)-thio]-1-propanesulfonic acid, 3-(2-benzthiazolylthio)-1-propanesulfonic acid sodium salt or mixtures thereof.  
     
     
         9 . The plating bath of  claim 6 , wherein the levelers comprise alkylated polyalkyleneimines, organo sulfo sulfones, dyes of the phenazine class, phenazine azo dyes, or mixtures thereof.  
     
     
         10 . The plating bath of  claim 6 , wherein the brighteners comprise 3-(benzthiazoyl-2-thio)-propylsulfonic acid sodium salt, 3-mercaptopropane-1-sulfonic acid sodium salt, ethylenedithiodipropylsulfonic acid sodium salt, bis-(p-sulfopehnyl)-disulfide disodium salt, bis-(ω-sulfobutyl)-disulfide disodium salt, bis-(ω-sulfohydroxypropyl)-disulfide disodium salt, bis-(ω-sulfopropyl)-disulfide disodium salt, bis-(ω-sulfopropyl)-sulfide disodium salt, methyl-(ω-sulfopropyl) sodium salt, methyl-(ω-sulfopropyl)-trisulfide disodium salt, O-ethyl-dithiocarbonic acid-S-(ω-sulfopropyl)-ester, potassium salt thioglycolic acid, thiophosphoric acid-O-ethyl-bis-(ω-sulfopropyl)-ester disodium salt, thiophosphoric acid-tri(ω-sulfopropyl)-ester trisodium salt, or mixtures thereof.  
     
     
         11 . The plating bath of  claim 6 , wherein the suppressors comprise carboxymethylcellulose, nonyphenolpolyglycol ether, octandiolbis-(polyalkylene glycolether), octanolpolyalkylene glycolether, oleic acidpolyglycol ester, polyethylenepropylene glycol, polyethylene glycol, polyethylene glycoldimethylether, polyoxypropylene glycol, polypropylene glycol, polyvinylalcohol, polyethylene oxide, stearic acidpolyglycol ester, stearyl alcoholpolyglycol ether, or mixtures thererof.  
     
     
         12 . The metal plating bath of  claim 1 , wherein the bath has a pH of from 0 to about 14.0.  
     
     
         13 . The metal plating bath of  claim 12 , wherein the bath has a pH of from 0 to about 8.0.  
     
     
         14 . A copper metal electroplating bath comprising a copper salt, and an additive consumption inhibiting compound having the formula:  
       (R 1 —NHR 2 OH) n X  
       where R 1  and R 2  are each independently hydrogen, C 1 -C 6  alkyl, n is 1 or 2, when n is 1, X is HSO 4   − , H 2 PO 4   − , NO 3   − , F − , Cl − , Br − , or I − , and when n is 2, X is SO 4   2− .  
     
     
         15 . The copper metal electroplating bath of  claim 14 , wherein the C 1 -C 6  alky comprises methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, isohexyl, 3-methylpentyl, 2,2-dimethyl or 2,3-dimethylbutyl.  
     
     
         16 . The copper metal electroplating bath of  claim 14 , wherein the additive inhibiting compound comprises hydroxylamine sulfate, hydroxylamine nitrate, hydroxylamine chloride, or mixtures thereof.  
     
     
         17 . The copper metal electroplating bath of  claim 14 , wherein the additive consumption inhibiting compounds comprise from about 0.001 g/L to about 100 g/L of the bath.  
     
     
         18 . The copper metal electroplating bath of  claim 17 , wherein the additive consumption inhibiting compounds comprise from about 0.01 g/L to about 20.0 g/L of the bath.  
     
     
         19 . The copper metal electroplating bath of  claim 14 , further comprising additives comprising brighteners, levelers, hardeners, wetting agents, malleability modifiers, ductility modifiers, deposition modifiers, suppressors or mixtures thereof.  
     
     
         20 . The copper metal electroplating bath of  claim 19 , wherein the brighteners comprise compounds having the structural formula: HO 3 —S—R 11 —SH; HO 3 S—R 11 —S—S—R 11 —SO 3 H, where R 11  is C 1 -C 6  alkyl group or an aryl group; or HO 3 —Ar—S—S—Ar—SO 3 H, where Ar is phenyl or naphthal; the alkyl and aryl groups may be alkyl groups, halo or alkoxy.  
     
     
         21 . The copper metal electroplating bath of  claim 19 , wherein the levelers comprise alkylated polyalkyleneimines, organic sulfo sulfonates, dyes of the phenazine class and phenazine azo dyes of mixtures thereof.  
     
     
         22 . The copper metal electroplating bath of  claim 19 , wherein the copper metal salt comprises copper halides, copper sulfates, copper alkane sulfonate, copper alkanol sulfonate, or mixtures thereof.  
     
     
         23 . The copper metal electroplating bath of  claim 14 , wherein the bath has a pH of from about 0 to about 8.0.  
     
     
         24 . A method for plating a metal on a substrate comprising: contacting the substrate with a metal plating bath; and applying sufficient current density to the plating bath to deposit the metal on the substrate; the plating bath comprises a metal salt of the metal copper, gold, silver, palladium, platinum, cobalt, cadmium, chromium, nickel, bismuth, indium, tin, rhodium, iridium, ruthenium, lead, or alloys thereof, and an additive consumption inhibiting compound having the formula:  
       (R 1 —NHR 2 OH) n X  
       where R 1  and R 2  are each independently hydrogen, C 1 -C 6  alkyl, n is 1 or 2, when n is 1, X is HSO 4   − , H 2 PO 4   − , NO 3   − , F − , Cl − , Br − , or I − , and when n is 2, X is SO 4   2− .  
     
     
         25 . The method of  claim 24 , wherein the C 1 -C 6  alkyl comprises methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, tert-pentyl, hexyl isohexyl, 3-methylpentyl, 2,2-dimethylbutyl, or 2,3-dimethylbutyl.  
     
     
         26 . The method of  claim 24 , wherein the additive consumption inhibiting compound comprises hydroxylamine sulfate, hydroxylamine nitrate, hydroxylamine chloride, or mixtures thereof.  
     
     
         27 . The method of  claim 24 , wherein the additive consumption inhibiting compound comprises from about 0.001 g/L to about 100 g/L of the bath.  
     
     
         28 . The method of  claim 24 , further comprising brighteners, levelers, hardeners, wetting agents, malleability modifiers, ductility modifiers, deposition modifiers, suppressants or mixtures thereof.  
     
     
         29 . The method of  claim 24 , wherein the brighteners comprise compounds of the formula: HO 3 S—R 11 —SH; HO 3 S—R 11 —S—S—R 11 —SO 3 H, where R 11  is C 1 -C 6  or an aryl group; and HO 3 —Ar—S—S—Ar—SO 3 H, where Ar is phenyl or naphthyl; and the alkyl and aryl groups may be unsubstituted or substituted with an alkyl group, a halo or an alkoxy.  
     
     
         30 . The method of  claim 24 , wherein the current density is from about 1 ASF to about 1000 ASF.  
     
     
         31 . The method of  claim 24 , wherein the substrate comprises a printed wiring board, and integrated circuit, an electrical contact surface, a connector, an electrolyte foil, a silicon wafer, a semi-conductor, a lead frame, a optoelectronic component, a solder bump on a wafer, a decorative article, a sanitary appliance and the like.  
     
     
         32 . A method for electroplating copper metal on a substrate comprising: contacting the substrate with a metal plating bath; and applying sufficient current density to the plating bath to deposit the copper on the substrate; the copper metal plating bath comprises a copper salt and an additive consumption inhibiting compound having the formula:  
       (R 1 —NHR 2 OH) n X  
       where R 1  and R 2  are each independently hydrogen, or C 1 -C 6  alkyl, n is 1 or 2, when n is 1, X is HSO 4   − , H 2 PO 4   − , NO 3   − , F −  Cl − , Br − , I − , and when n is 2, X is SO 4   2− .  
     
     
         33 . The method of  claim 32 , wherein the C 1 -C 6  alkyl comprises methyl, ethyl, propyl, isopropyl, butyl,isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, isohexyl, 3-methylpentyl, 2,2-dimethylbutyl, or 2,3-dimethylbutyl.  
     
     
         34 . The method of  claim 32 , wherein the additive consumption inhibiting compound comprises hydroxylamine sulfate, hydroxylamine nitrate, hydroxylamine chloride, or mixtures thereof.  
     
     
         35 . The method of  claim 32 , wherein the additive consumption inhibiting compound comprises from about 0.001 g/L to about 100 g/L of the bath.  
     
     
         36 . The method of  claim 32 , further comprising brighteners, levelers, hardeners, wetting agents, malleability modifiers, ductility modifiers, deposition modifiers, suppressants or mixtures thereof.  
     
     
         37 . The method of  claim 36 , wherein the brighteners comprise compounds of the formula: HO 3 S—R 11 —SH; HO 3 S—R 11 —S—S—R 11 , where R 11  is C 1 -C 6  alkyl or an aryl group; or HO 3 —Ar—S—S—Ar—SO 3 H, where Ar is phenyl or naphthyl; the C 1 -C 6  alkyl and aryl group may be unsubstituted or substituted with an alkyl group, halo or alkoxy group.  
     
     
         38 . The method of  claim 32 , wherein the substrate comprises a printed wiring board, an integrated circuit, an electrical contact surface, a connector, an electrolytic foil, a silicon wafer, a semi-conductor, a lead frame, a optoelectronic component, a solder bump on a wafer, a decorative article, a sanitary appliance, and the like.  
     
     
         39 . The method of  claim 32 , wherein the current density is from about 1ASF to about 1000 ASF.  
     
     
         40 . An apparatus comprising an electrical power source electrically connected to an anode and a cathode such that an electrical current can pass through the anode and cathode, the anode and the cathode are in contact with a metal plating bath such that when the electrical power source is operative a metal from the plating bath plates onto the cathode, the metal plating bath comprises a salt of a metal of copper, gold, silver, palladium, platinum, cobalt, cadmium, chromium, nickel, bismuth, indium, tin, rhodium, lead, ruthenium, iridium, or alloys thereof and an additive consumption inhibiting compound having the formula:  
       (R 1 —NHR 2 OH) n X  
       where R 1  and R 2  are each independently hydrogen, or C 1 -C 6  alkyl, and n is 1 or 2, when n is 1, X is HSO 4   − , H 2 PO 4   − , NO 3   − , F − , Cl − , Br −  or I − , and when n is 2, X is SO 4   2− .  
     
     
         41 . The apparatus of  claim 40 , wherein the additive consumption inhibiting compound comprises from about 0.01 g/L to about 20.0 g/L of the bath.  
     
     
         42 . The apparatus of  claim 40 , wherein the metal plating bath further comprises brighteners, levelers, hardeners, wetting agents, malleability modifiers, ductility modifiers, deposition modifiers, suppressors or mixtures thereof.  
     
     
         43 . The apparatus of  claim 40 , wherein the anode is an insoluble or soluble anode.  
     
     
         44 . The apparatus of  claim 43 , wherein the insoluble anode comprises metals of cobalt, nickel, ruthenium, rhodium, palladium, iridium, or platinum.  
     
     
         45 . The apparatus of  claim 44 , wherein the insoluble anode further comprises metals of titanium, zirconium, hafnium, vanadium, niobium, or tantalum.  
     
     
         46 . The apparatus of  claim 45 , wherein the insoluble anode further comprises beryllium, calcium, strontium, barium, scandium, yttrium, lanthanum, or rare earth elements.  
     
     
         47 . The apparatus of  claim 43 , wherein the insoluble anode comprises tantalum with a coating of iridium dioxide.  
     
     
         48 . The apparatus of  claim 40 , wherein the cathode comprises a wiring board, an integrated circuit, an electrical contact surface, a connector, an electrolytic foil, a silicon wafer, a semi-conductor, a lead frame, an optoelectronic component, a solder bump, a decorative article, a sanitary application and the like.