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arXiv · 1208.3069

Observation of fluctuation-induced tunneling conduction in micrometer-sized tunnel junctions

Yu-Ren Lai·Kai-Fu Yu·Yong-Han Lin·Jong-Ching Wu·Juhn-Jong Lin
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Abstract

Micrometer-sized Al/AlO$_{x}$/Y tunnel junctions were fabricated by the electron-beam lithography technique. The thin ($\approx$ 1.5--2 nm thickness) insulating AlO$_{x}$ layer was grown on top of the Al base electrode by O$_{2}$ glow discharge. The zero-bias conductances $G(T)$ and the current-voltage characteristics of the junctions were measured in a wide temperature range 1.5--300 K\@. In addition to the direct tunneling conduction mechanism observed in low-$G$ junctions, high-$G$ junctions reveal a distinct charge transport process which manifests the thermally fluctuation-induced tunneling conduction (FITC) through short nanoconstrictions. We ascribe the experimental realization of the FITC mechanism to originating from the formations of "hot spots" (incomplete pinholes) in the AlO$_{x}$ layer owing to large junction-barrier interfacial roughness.

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Yu-Ren Lai, Kai-Fu Yu, Yong-Han Lin, Jong-Ching Wu, Juhn-Jong Lin. 2012-08-15. Observation of fluctuation-induced tunneling conduction in micrometer-sized tunnel junctions. https://doi.org/10.1063/1.4749251

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