Related Experiment Video
Updated: Jun 21, 2026

Ohmic Contact Fabrication Using a Focused-ion Beam Technique and Electrical Characterization for Layer Semiconductor Nanostructures
Published on: December 5, 2015
Minority carrier effects in nanoscale Schottky contacts
1School of Materials, Arizona State University, Tempe, AZ 85287, USA.
Abstract:
We report the current-voltage behavior for nanoscale point contacts to Si(111) obtained in ultrahigh vacuum using scanning tunneling microscopy. Epitaxial CoSi(2) islands provide single-crystal contacts with well-defined size and shape. The zero bias conductance is found to be independent of the island size (10(2)-10(4) nm(2)) and shape, but varies strongly with the surface Fermi level position. This behavior is explained by the recombination-generation current from minority carriers at the free surface, which may be orders of magnitude larger than the majority carrier thermionic or tunnel currents across the contact interface. This can give rise to large shifts of the apparent ideality factor and Schottky barrier height for the point contact.
More Related Videos
Related Concept Videos
Metal-Semiconductor Junctions
Schottky Barriers
Schottky barriers arise when a metal with a work function (Φm) contacts a semiconductor with a different work function (Φs). Initially, electrons transfer until the Fermi levels of the metal and semiconductor align at equilibrium. For instance, if Φm > Φs, the semiconductor Fermi level is higher than the metal's before contact. The semiconductor's...
Schottky Barrier Diode
Biasing of Metal-Semiconductor Junctions
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
Carrier Generation and Recombination
This process is given by the generation rate G and is efficient due to the conservation of momentum between the valence band maximum and conduction band minimum.
Indirect generation involves an...
Carrier Transport
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
Semiconductors
Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining...

