Influence of the interface structure on the barrier height of homogeneous Pb/n-Si(111) Schottky contacts
Laboratorium für Festkörperphysik, Gerhard-Mercator-Universität Duisburg,
47048 Duisburg, Germany
Accepted: 7 September 1998
Published online: 15 February 1999
Unreconstructed interfaces may be prepared by evaporation of thick Pb films onto surfaces at room temperature. Current-voltage and capacitance-voltage characteristics of such Schottky contacts were measured in the temperature range between 140 and 300 K. The experimental data are analyzed by applying the thermionic-emission theory of inhomogeneous metal-semiconductor contacts as well as the "standard" thermionic-emission theory. From both methods the Schottky barrier height of laterally homogeneous contacts results as 0.724 eV. This value is by 74 meV larger than the previously observed barrier heights of laterally homogeneous interfaces. Similar differences were reported for unreconstructed and reconstructed Al- and contacts. The reduced barrier heights of all these interfaces are explained by the electric dipole associated with the stacking faults of reconstructions at surfaces and interfaces.
PACS: 73.30.+y – Surface double layers, Schottky barriers, and work functions / 73.40.Ei – Rectification
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999