Effect of nickel on the initial growth behavior of electroless Ni-Co-P alloy on silicon substrate

In this work the small amounts of NiSO4 was added to a basic electroless plating bath of CoSO4 with Na2H2PO2 as reducing agent for the deposition of Co-Ni-P film on a silicon substrate. The initial growth behavior, containing plating rate, chemical composition, crystal structure, surface morphology and micro-structure, of the electroless plating film was characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM). The results showed that the growth morphology variation of the Co-Ni-P films deposited in the basic CoSO4 + small amounts of NiSO4 bath is the same as that of Co-P film deposited in the basic CoSO4 bath, the plating rate of the Co-Ni-P film is much more rapid than that of the Co-P film, the Ni/Co wt.% in the Co-Ni-P film is greatly larger than that in the plating bath, and the structure of as-deposited film is crystalline at first stage and later stage.