AFM Analysis for Initial Stage of Electroless Displacement Deposition of Silver on Silicon Surface

Abstract

We deposit fine metal particles on silicon (Si) by a displacement reaction, which is the immersion of Si wafers into a metal-salt solution containing hydrofluoric acid, that consists of a local cathodic reduction of metal ions and a local anodic dissolution of Si. In this study, the displacement deposition of silver (Ag) nanoparticles on the Si(111) surface with an atomic step-terrace structure is investigated by atomic force microscopy. Ag particles are uniformly deposited on the Si surface without influence of the step-terrace structure. The particle density of the deposited Ag decreases and then increases with immersion times between 1 and 15 s. The step-terrace structure disappears and nanoholes are formed by an immersion time of 15 s. We propose a model of Ag particle density and Si surface changes with time.