Lin Yong-Han, Chiu Shao-Pin, Lin Juhn-Jong
Institute of Physics, National Chiao Tung University, Hsinchu 30010, Taiwan.
Nanotechnology. 2008 Sep 10;19(36):365201. doi: 10.1088/0957-4484/19/36/365201. Epub 2008 Jul 25.
The temperature behavior of how electrons propagate through an insulating electronic contact formed at the interface between a submicron Cr/Au electrode and a metallic RuO(2) nanowire (NW) has been studied between 300 and 1 K. The NWs are typically of ∼70 nm in diameter and a few microns long. The submicron electrodes were fabricated by the standard electron-beam lithography technique. By employing the two-probe method, the electronic contact resistances, R(c)(T), have been determined. We found that, in general, R(c) increases rapidly with decreasing temperature but eventually saturates at liquid-helium temperatures. Such a temperature behavior can be well described by a thermal fluctuation-induced tunneling (FIT) conduction process which considers the crossover feature from thermal activation conduction at high temperatures to simple elastic tunneling conduction at low temperatures. The wide applicability of this FIT model has further been established by employing metallic IrO(2) and Sn-doped In(2)O(3-x) NWs. This work demonstrates that the underlying physics for the charge transport properties of an insulating electronic contact can be well understood.
研究了电子在亚微米Cr/Au电极与金属RuO₂纳米线（NW）界面处形成的绝缘电子接触中传播时的温度行为，温度范围为300 K至1 K。NW的直径通常约为70 nm，长度为几微米。亚微米电极采用标准电子束光刻技术制备。通过采用两探针法，测定了电子接触电阻Rc(T)。我们发现，一般来说，Rc随温度降低而迅速增加，但最终在液氦温度下饱和。这种温度行为可以用热涨落诱导隧穿（FIT）传导过程很好地描述，该过程考虑了从高温下的热激活传导到低温下的简单弹性隧穿传导的交叉特征。通过使用金属IrO₂和Sn掺杂的In₂O₃₋ₓ NW，进一步确立了该FIT模型的广泛适用性。这项工作表明，绝缘电子接触的电荷传输特性的潜在物理机制可以得到很好的理解。
