Electrochemical nucleation and growth of copper on Si(1 1 1)

In this paper we report on the deposition of copper on n-Si(1 1 1) from 1 mM CuSO4+0.1 M H2SO4 (pH=1) solution. Voltammograms revealed a deposition peak characteristic of diffusion limited growth. Atomic force microscopy (AFM) images after deposition of a few monolayers showed that deposition occurs by Volmer–Weber island growth. From analysis of AFM images obtained as a function of deposition time, we show that the nucleus density increases linearly with time, consistent with progressive nucleation. Deposition transients follow the rate law for progressive nucleation and 3D diffusion limited growth over a wide range of potentials. Ex situ AFM imaging of copper deposition on annealed miscut surfaces revealed that the copper cluster density is higher in regions of high step density and that nucleation occurs preferentially at step edges.