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