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Negative differential conductance in strained Si point contacts and wires

Authors :
Khalid EzzEldin Ismail
Steven J. Koester
J. O. Chu
Kam-Leung Lee
Source :
Applied Physics Letters. 71:1528-1530
Publication Year :
1997
Publisher :
AIP Publishing, 1997.

Abstract

The observation of negative differential conductance (NDC) in simple nanostructure geometries fabricated on high-mobility Si/SiGe strained-layer heterostructures is reported. The NDC is observed in the drain characteristic of etch-defined “point contacts” with lithographic width and length of 0.22, and 0.12 μm, respectively. Current peak-to-valley ratios as large as 2.0 are observed at T=1.3 K. The NDC is also observed in “wire” geometries as long as 19 μm, and can persist to temperatures as high as 83 K, with a minimum in the differential conductance observable at 103 K. The NDC in long wires is accompanied by the formation of a high-field domain at the drain end of the wire. The effect is only observed in laterally constricted geometries, but is not a result of quantum confinement or impurity-related trapping. We suggest that the NDC and the attendant domain formation are caused by phonon emission by hot electrons within the constricted geometry.

Details

ISSN :
10773118 and 00036951
Volume :
71
Database :
OpenAIRE
Journal :
Applied Physics Letters
Accession number :
edsair.doi...........125d0179c4668800615fc9f78f7f89fb
Full Text :
https://doi.org/10.1063/1.119956