Method for the electrolytic deposition of metals

Abstract

The present invention relates to a method as well as and electrolyte for the electrolytic deposition of mat or half-glossy copper layers from an acid electrolyte in a pull-through device. The method according to the invention is operated with current densities comprises between 10 and 100 A/dm2 and is suitable for depositing sufficiently thick copper layers in high-speed pull-through devices. The electrolyte according to the invention comprises apart from copper, alkyl sulfonic acid.

1 . A process for the electrolytic deposition of a mat or half-glossy copper layer from an acidic electrolytic comprising: 
 contacting an elongate substrate selected from the group consisting of wire, tube, band, and ribbon with an aqueous acidic electrolytic solution comprising copper ions and an alkyl sulfonic acid by pulling the substrate through the electrolytic solution wherein a first segment of the substrate is in contact with the aqueous acidic electrolytic solution while a second segment of the substrate is not in contact with the aqueous acidic electrolytic solution; and    passing a current at a density of at least about 10 A/dm 2  between an anode in contact with said electrolytic solution and a cathode comprising said substrate.    
   
   
       2 . The process of  claim 1  wherein said pulling is continuous.  
   
   
       3 . The process of  claim 1  wherein said pulling is intermittent.  
   
   
       4 . The process of  claim 2  wherein said pulling is at a linear velocity of the substrate relative to said electrolytic solution of at least about 0.5 m/sec.  
   
   
       5 . The process of  claim 2  wherein said pulling is at a linear velocity of the substrate relative to said electrolytic solution of at least about 5 m/sec.  
   
   
       6 . The process of  claim 2  wherein said pulling is at a linear velocity of the substrate relative to said electrolytic solution of between about 5 m/sec and about 20 m/sec.  
   
   
       7 . The process of  claim 1  wherein said electrolytic solution is contained in a plating vessel and said substrate is caused to move within the electrolytic solution relative to said vessel.  
   
   
       8 . The process of  claim 1  wherein the substrate is pulled continuously or intermittently through said electrolytic solution at a linear velocity of at least about 0.8 m/sec. relative to a fixed locus of points within said vessel parallel or tangential to a path on which said substrate passes through said vessel.  
   
   
       9 . The process as set forth in  claim 8  wherein said substrate comprises a wire and said velocity is between about 5 and about 20 m/sec.  
   
   
       10 . The process of  claim 1  wherein the substrate has a residence time of between about 5 and about 25 seconds within a region of said electrolytic solution wherein current is passed between said anode and said cathode at said current density.  
   
   
       11 . The process of  claim 1  wherein said electrolytic solution further comprises a naphtholethoxylate nonionic surfactant.  
   
   
       12 . The process of  claim 1  wherein said electrolytic solution further comprises a condensation polymer of naphthol bearing ring-substituted sulfonic acid groups.  
   
   
       13 . The process of  claim 1  wherein the electrolytic solution comprises at least about 40 g/L Cu ions, a naphtholethoxylate nonionic surfactant, a condensation polymer of naphthol bearing ring-substituted sulfonic acid groups, halide ions, and at least about 50 ml/L methane sulfonic acid.  
   
   
       14 . The process of  claim 1  wherein the electrolytic solution comprises at least about 75 g/L Cu ions.  
   
   
       15 . The process of  claim 13  wherein the electrolytic solution comprises at least about 75 g/L Cu ions.  
   
   
       16 . The process of  claim 1  wherein sulfuric acid and other acid components are substantially excluded from the electrolytic solution.  
   
   
       17 . The process of  claim 1  wherein said current density is at least about 40 A/dm2 and said plating occurs at a current efficiency of at least about 75%.  
   
   
       18 . The process of  claim 1  wherein said current density is at least about 80 A/dm2 and said plating occurs at a current efficiency of at least about 75%.  
   
   
       19 . A process for the electrolytic deposition of a mat or half-glossy copper layer on a substrate comprising reducing copper ions from an acid electrolytic solution onto said substrate at a current efficiency of at least about 75% and a current density between approximately 40 and 100 A/dm 2  as determined with reference to the area of the substrate being plated.  
   
   
       20 . An electrolyte or combination of electrolytes for use in preparation of electrolytic solutions that function as plating baths for electrodeposition of copper, said electrolyte or combination of electrolytes comprising, on an anhydrous basis, between about 18 wt. % and about 40 wt. % copper and between about 22 wt. % and about 58 wt. % methane sulfonic acid.  
   
   
       21 . The electrolyte or combination of electrolytes of  claim 20  further comprising between about 2 wt. % and about 13 wt. % of a naphtholethoxylate nonionic surfactant.  
   
   
       22 . The electrolyte or combination of electrolytes of  claim 21  further comprising a condensation polymer of naphthol bearing ring-substituted sulfonic acid groups.  
   
   
       23 . The electrolyte or combination of electrolytes of  claim 20  further comprising between about 0.02 wt. % and about 0.04 wt. % halide ions.  
   
   
       24 . An electrolyte or combination as set forth in  claim 20  that is pre-packaged for introduction into water to provide an electrolytic solution which may serve as the plating bath for electrodeposition of copper.  
   
   
       25 . A supply or kit comprising the components of the electrolyte or combination of  claim 20  wherein at least some but not all components are pre-mixed and packaged separately from one or more other components.