Plating baths and methods for electroplating selenium and selenium alloys

Abstract

Plating bath solutions and methods for depositing selenium generally include an aqueous plating bath containing a soluble selenium source and a soluble surfactant additive, wherein the soluble surfactant additive is selected from the group consisting of an alkane sulfonic acid, an alkane phosphonic acid and mixtures thereof, wherein the alkane group defining the alkane sulfonic acid and the alkane phosphonic acid has less than 25 carbon atoms The method includes immersing a conductive substrate to be plated into the aqueous plating bath; and electroplating selenium onto the substrate to form a continuous and particle free film.

What is claimed is: 
     
         1 . An electroplating solution for plating selenium on a substrate comprises:
 at least one bath soluble selenium source;   at least one bath soluble surfactant additive of the formulae RSO 3 H and/or RH 2 PO 3 , wherein R is an alkyl group of 1 to 25 carbon atoms; and   a solvent, wherein the solution is at a pH of about 2 to about 4 and is at a temperature of about 15° C. to about 45° C.   
     
     
         2 . The electroplating solution of  claim 1 , wherein the at least one bath soluble selenium source is selected from the group consisting of selenium oxide and selenous acid. 
     
     
         3 . The electroplating solution of  claim 1 , wherein the alkyl group is 1 to 12 carbon atoms. 
     
     
         4 . The electroplating solution of  claim 1 , wherein the at least one bath soluble selenium source is in an amount of about 0.001 M to about 1 M. 
     
     
         5 . The electroplating solution of  claim 1 , wherein the at least one bath soluble selenium source is in an amount of about 0.01M to about 1 M. 
     
     
         6 . The electroplating solution of  claim 1 , wherein the at least one bath soluble surfactant additive is at a concentration of about 1 milligram per liter to 1 grams per liter. 
     
     
         7 . The electroplating solution of  claim 1 , wherein the at least one bath soluble surfactant additive is at a concentration of about 5 milligram per liter to 750 milligrams per liter. 
     
     
         8 . The electroplating solution of  claim 1 , wherein the at least one bath soluble surfactant additive is at a concentration of about 10 milligrams per liter to 250 milligrams per liter. 
     
     
         9 . The electroplating solution of  claim 1 , wherein the bath is at a pH of about 3 to about 4 and is at a temperature of about 15° C. to about 45° C. 
     
     
         10 . The electroplating solution of  claim 1 , further comprising at least one of indium ions, gallium ions and copper ions. 
     
     
         11 . The electroplating solution of  claim 1 , wherein the bath is acidic. 
     
     
         12 . The electroplating solution of  claim 1 , wherein the solvent comprises water. 
     
     
         13 . An electroplating solution for plating selenium alloys on a substrate comprises:
 at least one bath soluble selenium sources selected from the group consisting of selenium oxide, selenious acid, and mixtures thereof;   at least one of indium ions, gallium ions and copper ions;   at least one bath soluble surfactant additive of the formulae RSO 3 H and/or RH 2 PO 3 , wherein R is an alkyl group of 1 to 25 carbon atoms; and   a solvent, wherein the solution has a pH within a range of about 2 to about 4 and is at a temperature within a range of about 18° C. to about 25° C.   
     
     
         14 . The electroplating solution of  claim 13 , wherein the solvent comprises water. 
     
     
         15 . The electroplating solution of  claim 13 , wherein the at least one bath soluble surfactant additive is at a concentration of about 10 milligram per liter to 100 milligrams per liter. 
     
     
         16 . The electroplating solution of  claim 13 , wherein the surfactant additive is selected from the group consisting of decane sulfonic acid, undecanesulfonic acid, hexylphosphoniuc acid, salts thereof, and mixtures thereof. 
     
     
         17 . The electroplating solution of  claim 13 , wherein the at least one bath soluble selenium source is in an amount of about 0.001 M to about 1 M. 
     
     
         18 . The electroplating solution of  claim 13 , wherein the at least one bath soluble selenium source is in an amount of about 0.01 M to about 1 M.