Mechanisms of current flow in metal-semiconductor ohmic contacts

Journal Article · Thu Nov 15 00:00:00 EST 2007 · Semiconductors

DOI:https://doi.org/10.1134/S1063782607110012· OSTI ID:21087973

Gol'dberg, Yu A ^[1]

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1. Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)

Published data on the properties of metal-semiconductor ohmic contacts and mechanisms of current flow in these contacts (thermionic emission, field emission, thermal-field emission, and also current flow through metal shunts) are reviewed. Theoretical dependences of the resistance of an ohmic contact on temperature and the charge-carrier concentration in a semiconductor were compared with experimental data on ohmic contacts to II-VI semiconductors (ZnSe, ZnO), III-V semiconductors (GaN, AlN, InN, GaAs, GaP, InP), Group IV semiconductors (SiC, diamond), and alloys of these semiconductors. In ohmic contacts based on lightly doped semiconductors, the main mechanism of current flow is thermionic emission with the metal-semiconductor potential barrier height equal to 0.1-0.2 eV. In ohmic contacts based on heavily doped semiconductors, the current flow is effected owing to the field emission, while the metal-semiconductor potential barrier height is equal to 0.3-0.5 eV. In alloyed In contacts to GaP and GaN, a mechanism of current flow that is not characteristic of Schottky diodes (current flow through metal shunts formed by deposition of metal atoms onto dislocations or other imperfections in semiconductors) is observed.

• OSTI ID: 21087973
• Journal Information: Semiconductors, Vol. 41, Issue 11; Other Information: DOI: 10.1134/S1063782607110012; Copyright (c) 2007 Nauka/Interperiodica; Article Copyright (c) 2007 Pleiades Publishing, Ltd; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7826
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALLOYS
ALUMINIUM NITRIDES
CHARGE CARRIERS
DIAMONDS
DISLOCATIONS
DOPED MATERIALS
ELECTRIC CURRENTS
FIELD EMISSION
GALLIUM ARSENIDES
GALLIUM NITRIDES
GALLIUM PHOSPHIDES
INDIUM NITRIDES
INDIUM PHOSPHIDES
METALS
SCHOTTKY BARRIER DIODES
SEMICONDUCTOR MATERIALS
SILICON CARBIDES
THERMIONIC EMISSION
ZINC OXIDES
ZINC SELENIDES