CORRELATION BETWEEN ATOMIC-SCALE STRUCTURES AND MACROSCOPIC ELECTRICAL PROPERTIES OF METAL-COVERED Si(111) SURFACES

Abstract

In this review, we discuss the relation between the atomic-scale structures (atomic arrangements and electronic states) and the macroscopic electrical properties (surface conductance and Schottky barriers) of metal(Ag, Au, or In)-covered Si (111) surfaces. These surfaces have been one of the most intensively investigated systems with the use of a variety of modern surface science techniques, and diversified information at atomic scales has been obtained. The data of reflection high-energy electron diffraction, scanning tunneling microscopy/spectroscopy, photoemission spectroscopies, and others are utilized here for characterizing the structures. Surface conductance and Schottky barriers, on the other hand, have also been the major areas in semiconductor physics for, especially device-oriented, research, but these have rarely been studied in combination with atomic-scale structures. These electrical properties have recently been found to be crucially dependent on the local atomic structures of well-defined surfaces/interfaces. The atomic arrangements and the resulting surface/interface electronic states govern the Fermi-level pinning and band bending which determine the electrical properties of semiconductor surfaces/interfaces.