Processes for the deposition or removal of metals

A method for electrolytically removing a metal from an electrically conductive substrate which method comprises employing said substrate as the anode in an electrolytic cell comprising said anode and a cathode immersed in an electrically conductive bath comprising sulfuric acid and chalcogen-containing compound soluble in said bath and having the empirical formula ##STR6## wherein X is a chalcogen, each of R.sub.1 and R.sub.2 is selected from hydrogen, NR.sub.3 R.sub.4 and NR.sub.5, at least one of R.sub.1 and R.sub.2 is other than hydrogen, each of R.sub.3 and R.sub.4 is selected from hydrogen and monovalent organic radicals, and R.sub.5 is selected from divalent organic radicals, the molar ratio of said chalcogen-containing compound to said sulfuric acid is about 1 to about 10, and the molar ratio of water to the combination of said sulfuric acid and said chalcogen-containing compound is about 20 or less, and impressing a voltage differential across said cathode and said anode.

A method for electrolytically plating a metal on an electrically conductive substrate, which method comprises suspending said electrically conductive substrate as a cathode in an electrolytic cell comprising an anode and said cathode immersed in an electrolytic bath comprising sulfuric acid, a chalcogen-containing compound selected from the group consisting of urea, formamide, thiourea, and combinations thereof, and a metal ion platable on said substrate, wherein the molar ratio of said chalcogen-containing compound to said sulfuric acid is within the range of about 1 to about 10, the molar ratio of water to the combination of said chalcogen-containing compound and said sulfuric acid is about 20 or less, the [H.sub.2 O]/[chalcogen compound][H.sub.2 SO.sub.4 molarity product ratio is about 50 or less, and causing said platable metal ion to plate on said substrate.

A method for electrolytically depositing a metal on a substrate which comprises employing said substrate as a cathode in an electrolytic cell comprising an anode and said cathode immersed in an anhydrous, electrically conductive bath comprising platable metal ions, sulfuric acid and a chalcogen-containing compound soluble in said bath and having the empirical formula ##STR7## wherein X is a chalcogen, each of R.sub.1 and R.sub.2 is selected from hydrogen, NR.sub.3 R.sub.4 and NR.sub.5, at least one of R.sub.1 and R.sub.2 is other than hydrogen, each of R.sub.3 and R.sub.4 is selected from hydrogen and monovalent organic radicals, R.sub.5 is selected from divalent organic radicals, and the molar ratio of said chalcogen-containing compound to said acid is about 1 to about 10.

A method for electrolytically depositing a metal on or removing a metal from the substrate which method comprises conducting said metal deposition or removal in an electrolytic bath comprising sulfuric acid and a chalcogen-containing compound soluble in said bath and having the empirical formula ##STR8## wherein X is S or O, each of R.sub.1 and R.sub.2 is selected from hydrogen, NR.sub.3 R.sub.4 and NR.sub.5, at least one of R.sub.1 and R.sub.2 is other than hydrogen, each of R.sub.3 and R.sub.4 is selected from hydrogen and monovalent organic radicals, and R.sub.5 is selected from divalent organic radicals, the molar ratio of said chalcogen-containing compound to said sulfuric acid is at least about 1, the molar ratio of water to the combination of said acid and said chalcogen-containing compound is about 20 or less, and the [H.sub.2 O]/[chalcogen compound][H.sub.2 SO.sub.4 molarity product ratio is about 50 or less.

A method for immersion plating platable metal ions on a substrate which comprises a metal less noble than said platable metal ions, which method comprises suspending said substrate in an electrolyte containing said platable metal ions, sulfuric acid, and a chalcogen-containing compound soluble in said bath and having the empirical formula:

• ##STR9## wherein X is is a chalcogen, each of R.sub.1 and R.sub.2 is selected from hydrogen, NR.sub.3 R.sub.4 and NR.sub.5, at least one of R.sub.1 and R.sub.2 is other than hydrogen, each of R.sub.3 and R.sub.4 is selected from hydrogen and monovalent organic radicals, and R.sub.5 is selected from divalent organic radicals, the molar ratio of said chalcogen-containing compound to said sulfuric acid is at least about 1, the molar ratio of water to the combination of said sulfuric acid and said chalcogen-containing compound is about 20 or less, and the [H.sub.2 O]/[chalcogen compound][H.sub.2 SO.sub.4 ] molarity product ratio is about 50 or less, under conditions sufficient to plate said metal ions on said substrate.