Electroless deposition of transition metals

Claim 1

In a method for electrolessly depositing copper upon a substrate from a bath which includes in admixture: a source of copper cation, a reducing agent and a complexing agent, and which is characterized by said complexing agent rendering said bath operable through a wide range of pH values between about 4 and about 14, the pH value being selected to be the optimum value for the bath, for the substrate and for a selected one of a variety of reducing agents which is selected from the group consisting of formaldehyde, a hypophosphite compound, a boron-nitrogen compound, a borohydride, and an alkylamine borane, the improvement for electrolessly depositing copper at said wide range of pH values comprising: including within the electroless copper bath an organophosphorus complexing agent selected from the group consisting of compounds having the general formulas: ##STR9## wherein R 1 is alkyl having from 1 to 5 carbon atoms, alkali metal and ammonium salts of said compounds, and ##STR10## wherein R 2 is ##STR11## R 3 is selected from the class consisting of R 2 and --CH 2 CH 2 OH, and R 4 is selected from the group consisting of R 2 , --CH 2 CH 2 OH, and ##STR12## wherein each M is independently selected from the group consisting of H, NH 4 and alkali metal, and "n" is an integer from 1 to 6 inclusive; and immersing the substrate within the bath while operating the electroless copper deposition bath at said optimum pH value to maintain optimum deposition conditions for the substrate and for the selected reducing agent.