Influence of the Chemical Properties of the Substrate on Silicon Quantum Dot Nucleation

Abstract

We have studied the influence of SiO2SiO2 surface properties on the nucleation and growth of silicon quantum dots (Si-QDs) deposited by SiH4SiH4 low-pressure chemical vapor deposition (LPCVD). First, the effect of siloxane groups (Si-O-Si) strain at the SiO2SiO2 surface layer, characterized by Fourier transform infrared (FTIR) spectroscopy, is studied. We evidenced an increase of Si-QD nucleation with the strain of siloxane groups in the SiO2SiO2 substrate layer. Second, the Si-QD nucleation strongly depends on the surface silanol group (Si-OH) density. This density, controlled by chemical and thermal treatments, is measured by multiple internal reflexion (MIR) FTIR. Very high Si-QD densities larger than 1012/cm21012/cm2 are obtained on highly hydroxylated SiO2.SiO2. © 2003 The Electrochemical Society. All rights reserved.