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ABSTRACT

The phenomenological predictions for the cutoff frequency of carbon nanotube transistors and the predictions of the effects of parasitic capacitances on AC nanotube transistor performance are presented. The influence of quantum capacitance, kinetic inductance, and ballistic transport on the high-frequency properties of nanotube transistors is analyzed. The challenges of impedance matching for ac nano-electronics in general, and how integrated nanosystems can solve this challenge, are presented.
Introduction

Nano electronic devices fall into two classes: tunnel devices and ballistic transport devices. In Tunnel devices single electron effects occur if the tunnel resistance is larger than h/e = 25 KO. In Ballistic devices with cross sectional dimensions in the range of quantum mechanical wavelength of electrons, the resistance is of order h/e = 25 KO. This high resistance may seem to restrict the operational speed of nano electronics in general. However the capacitance values and drain source spacing are typically small which gives rise to very small RC times and transit times of order of ps or less. Thus the speed may be very large, up to THz range.


The goal of this seminar is to present the models an performance predictions about the effects that set the speed limit in carbon nanotube transistors, which form the ideal test bed for understanding the high frequency properties of Nano electronics because they may behave as ideal ballistic 1d transistors.