Electrochemistry of Gold Deposition on n-Si(100)

The electrochemical deposition of gold on n‐type silicon from KAu ( CN ) 2 solutions was investigated by performing a detailed study of the nucleation and growth kinetics. Deposition occurs by progressive nucleation and diffusion‐limited growth of three‐dimensional hemispherical islands over a wide range of potentials and KAu ( CN ) 2 concentrations. It is shown that for a silicon/gold electrode, the applied potential is dropped over the silicon/gold interface at potentials more positive than 0 V, while at potentials more negative than 0 V, the applied potential is dropped over the Helmholtz layer at the gold/solution interface. The influence of these observations on the applicability of nucleation models derived for metal‐on‐metal deposition to metal deposition onto semiconductors is discussed.