High frequency Scanning Gate Microscopy and local memory effect of carbon nanotube transistors

Staii, Cristian; Shao, Rui; Bonnell, Dawn A.; Johnson Jr, Alan T.

High frequency Scanning Gate Microscopy and local memory effect of carbon nanotube transistors

Authors

Description

We use impedance spectroscopy to measure the high frequency properties of single-walled carbon nanotube field effect transistors (swCN-FETs). Furthermore, we extend Scanning Gate Microscopy (SGM) to frequencies up to 15MHz, and use it to image changes in the impedance of swCN-FET circuits induced by the SGM-tip gate. In contrast to earlier reports, the results of both experiments are consistent with a simple RC parallel circuit model of the swCN-FET, with a time constant of 0.3 ms. We also use the SGM tip to show the local nature of the memory effect normally observed in swCN-FETs, implying that nanotube-based memory cells can be miniaturized to dimensions of the order of tens of nm.
7 pages, 3 figures, to appear in Nano Letters