Scanning tunneling microscopic study of the effects of surface conduction on the electrical transport properties of nanosized Schottky contacts between FeSi_2 nanoislands and Si(111)

摘要

Electrical transport properties of Schottky nanocontacts between FeSi_2 nanoislands and p(n)-type Si(111) are investigated by a scanning tunneling microscope with tip touching the islands. By comparing the current-voltage curves of the FeSi_2 islands with and without a surrounding trench, we extracted the contribution of surface leakage current from the total current and found that the surface conduction dominates the electrical transport of the nanocontacts. The surface leakage current increases linearly with reverse bias but increases exponentially with forward bias, which is explained by the surface-state conduction and surface recombination-generation conduction of minority carriers.