An Infrared Study of H8Si8O12 Cluster Adsorption on Si (100) Surfaces

Published

May 1, 1998

Author(s)

J Eng, Krishnan Raghavachari, L M. Struck, Y J. Chabal, B E. Bent, M M. Banaszak-Holl, F R. McFeely, A M. Michaels, G W. Flynn, S B. Christman, E E. Chaban, G P. Williams, K Radermacher, S Mantl

Abstract

Motivated by an ongoing controversy regarding the proper interpretation of x-ray photoelectron spectra of Si/SiO₂ interfaces derived from the adsorption of H₈Si₈O₁₂ spherosiloxane clusters on Si(100) surfaces, we have studied the adsorption geometry of the H₈Si₈O₁₂ clusters on deuterium-passivated and clean Si(100) surfaces by using external reflection infrared spectroscopy. Access to frequencies below 1450 cm^1- was made possible through the use of specially prepared samples which have a buried metallic CoSi₂ layer that acts as an internal mirror. A comparison of the infrared spectrum obtained for clusters on a deuterium-passivated Si(100) surface at 130 K with an infrared spectrum reported previously in the literature for the clusters in a carbon tetrachloride solution reveals that the clusters are only weakly physisorbed on the D/Si(100) surface and also provides evidence for the purity of the cluster source. We also present infrared spectra of clusters directly chemisorbed on the Si(100) via attachment by one vertex. A complete assignment of the observed vibrational features, for both physisorbed and chemisorbed clusters, has been made based upon comparisons with the results obtained in ab-initio calculations using gradient-corrected density functional methods.

Citation

Journal of Chemical Physics

Volume

108

Issue

No. 20

Pub Type

Journals

Keywords

ab initio calculations, B3-LYP gradient-corrected density, H8Si8O12 spherosiloxane clusters, infrared spectroscopy, IR, Si(100), Si/SiO2 interface, silicon surface, water

Citation

Eng, J. , Raghavachari, K. , Struck, L. , Chabal, Y. , Bent, B. , Banaszak-Holl, M. , McFeely, F. , Michaels, A. , Flynn, G. , Christman, S. , Chaban, E. , Williams, G. , Radermacher, K. and Mantl, S. (1998), An Infrared Study of H₈Si₈O₁₂ Cluster Adsorption on Si (100) Surfaces, Journal of Chemical Physics (Accessed October 17, 2025)