Understanding and improving carbon nanotube-electrode contact in bottom-contacted nanotube gas sensors
Understanding and improving carbon nanotube-electrode contact in bottom-contacted nanotube gas sensors
复制标题
DOI：
10.1016/j.snb.2020.129406
复制
发表时间：
2021-01-07
影响因子：
8.4
通讯作者：
Hierold, Christofer
中科院分区：
文献类型：
--
作者：
Jung, Seoho;Hauert, Roland;Hierold, Christofer
采用干转移技术制造的悬浮碳纳米管场效应晶体管显示出作为超低功耗、无滞后气体传感器的强大前景。然而，在纳米管和电极表面之间建立良好的电接触的困难通常限制了可用作低功率气体传感器的低电阻器件的产量。在这项工作中，通过在放置纳米管之前用氩离子蚀刻去除电极表面的顶层，显着降低了纳米管-金属界面处的接触电阻及其分布。与转移后退火相结合，这种转移前电极表面清洁将晶体管的中值导通电阻降低了一个数量级（从 1.56 MOhm 到 143 kOhm），并将四分位数范围降低了两个以上数量级（从 9.38 MOhm 到 59 kOhm）。这项工作所展示的持续改善纳米管-金属接触的能力是超净纳米管晶体管和碳纳米管气体传感器制造的重大进步。
Suspended carbon nanotube field-effect transistors fabricated with a dry transfer technique demonstrate strong promise as ultra-low-power, hysteresis-free gas sensors. However, the difficulty of establishing a good electrical contact between a nanotube and the electrode surface often limits the yield of low-resistance devices that can operate as low-power gas sensors. In this work, the contact resistance at the nanotube-metal interface and the distribution thereof are reduced significantly by removing the top layer of electrode surface with Ar-ion etching directly before nanotube placement. Combined with post-transfer annealing, this pre-transfer electrode surface cleaning reduces the median ON-resistance of transistors by an order of magnitude-from 1.56 MOhm to 143 kOhm-and the interquartile range by more than two orders of magnitude-from 9.38 MOhm to 59 kOhm. The ability to consistently improve nanotube-metal contact demonstrated in this work is a significant advance in the fabrication of ultraclean nanotube transistors and carbon nanotube gas sensors.