Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States.
Nano Lett. 2011 May 11;11(5):1881-6. doi: 10.1021/nl200063x. Epub 2011 Apr 6.
We present a technique to increase carbon nanotube (CNT) density beyond the as-grown CNT density. We perform multiple transfers, whereby we transfer CNTs from several growth wafers onto the same target surface, thereby linearly increasing CNT density on the target substrate. This process, called transfer of nanotubes through multiple sacrificial layers, is highly scalable, and we demonstrate linear CNT density scaling up to 5 transfers. We also demonstrate that this linear CNT density increase results in an ideal linear increase in drain-source currents of carbon nanotube field effect transistors (CNFETs). Experimental results demonstrate that CNT density can be improved from 2 to 8 CNTs/μm, accompanied by an increase in drain-source CNFET current from 4.3 to 17.4 μA/μm.
我们提出了一种将碳纳米管（CNT）密度增加到超过原始生长密度的技术。我们进行多次转移，即将 CNT 从几个生长晶圆转移到同一个目标表面，从而在线性增加目标基底上的 CNT 密度。这种通过多个牺牲层转移 CNT 的工艺具有高度的可扩展性，我们证明了线性 CNT 密度可以扩展到 5 次转移。我们还证明，这种线性 CNT 密度的增加导致碳纳米管场效应晶体管（CNFET）的漏源电流呈理想的线性增加。实验结果表明，CNT 密度可以从 2 提高到 8 个/μm，同时漏源 CNFET 电流从 4.3 增加到 17.4 μA/μm。
