A study on extraneous deposition of electroless Ni-W-P alloy films on transparent electrode.

The extraneous deposition of electroless Ni-W-P alloy films on the transparent electrode was investigated. A degreasing process suppressed thick extraneous deposition, while low concentrations of dissolved oxygen resulted in granular extraneous deposition which was affected by the size of the substrate and the orientation of the pattern. The composition of the granular extraneous deposits was almost the same as that of normal deposition, except it was slightly richer in phosphorus and poorer in nickel. The occurrence of granular extraneous deposition was closely related with the amount of adsorption hydrogen, which was reduced by the higher concentration of dissolved oxygen and by stirring.