NUCLEATION GROWTH AND STRUCTURE OF THIN NI-P FILMS

The nucleation, early growth, and structure of Ni-P on SnCl2-PdCl2 activated dielectric substrates were studied. The SnCl2-PdCl2 treatment was found to provide small catalytic sites on the substrate, serving as the nuclei for Ni-P growth. The average diameter of catalytic sites was estimated to be less than 10Å. The microscopic time rate of Ni-P growth on the nuclei was found to be constant and the growth to be isotropic. The resulting Ni-P deposit in the early stages of growth consists of circular islands. The surface density σ of islands were affected by activation. In later stages of growth, the circular Ni-P islands merged to form a continuous film. The critical film thickness at which continuity is attained is shown to be a function of σ. The structure of as-deposited islands, as well as that of fresh continuous film, was determined by electron diffraction to be liquidlike. © 1968, The Electrochemical Society, Inc. All rights reserved.