IBM T. J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, New York 10598, United States.
ACS Nano. 2012 Feb 28;6(2):1109-15. doi: 10.1021/nn203516z. Epub 2012 Jan 24.
The large amount of hysteresis and threshold voltage variation in carbon nanotube transistors impedes their use in highly integrated digital applications. The origin of this variability is elucidated by employing a top-coated, hydrophobic monolayer to passivate bottom-gated devices. Compared to passivating only the supporting substrate, it is found that covering the nanotube channel proves highly effective and robust at improving device-to-device consistency-hysteresis and threshold voltage variation are reduced by an average of 84 and 53%, respectively. The effect of gate and drain-source bias on hysteresis is considered, showing strong dependence that must be accounted for when analyzing the effectiveness of a passivation layer. These results provide both key insight into the origin of variability in carbon nanotube transistors and a promising path for resolving this significant obstacle.
大量的滞后和阈值电压变化会阻碍碳纳米管晶体管在高度集成的数字应用中的使用。通过采用顶部涂层的疏水性单层来钝化底栅器件，可以阐明这种可变性的起源。与仅钝化支撑衬底相比，发现覆盖纳米管通道在提高器件间一致性方面非常有效和稳健-滞后和阈值电压变化分别平均降低了 84%和 53%。还考虑了栅极和漏源偏压对滞后的影响，显示出很强的依赖性，在分析钝化层的有效性时必须考虑到这种依赖性。这些结果不仅为碳纳米管晶体管的变异性提供了关键的见解，而且为解决这一重大障碍提供了有希望的途径。
