S. Pal, M. K. Sanyal, S. Hazra, and S. Kundu
Surface Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064, India

F. Schreiber
Max-Planck-Institut fur Metallforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany; Institut fur Theoretische und Angewandte Physik, Universitat Stuttgart, D-70550 Stuttgart, Germany

J. Pflaum
Physikalisches Institut, Universitat Stuttgart, D-70569 Stuttgart, Germany

E. Barrena and H. Dosch
Max-Planck-Institut fur Metallforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany

Nanometer sized Au clusters deposited on a silicon substrate forming Au-SiO₂-Si structure are important for the development of contacts in nanotechnology. Systematic x-ray reflectivity, scanning probe microscopy, and scanning tunneling spectroscopy measurements were done to understand the relationship between morphology and electrical transport properties of this nanostructural metal-insulator-semiconductor system. The presence of an interfacial layer at the metal-insulator interface dictates the tunneling current through this structure and exhibits a gap leading to a suppression of current. Local density of states and electron density/thickness of the interfacial layer have been extracted from the measurements to understand the evolution of metallicity of this Au-SiO₂-Si structure.