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High performance n-doped carbon nanotube field-effect transistors

M. Radosavljevic·J. Appenzeller·Ph. Avouris·J. Knoch
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Abstract

We describe a robust technique for the fabrication of high performance vertically scaled n-doped field-effect transistors from large band gap carbon nanotubes. These devices have a tunable threshold voltage in the technologically relevant range (-1.3V < V_th < 0.5V) and can carry up to 5-6 muA of current in the on-state. We achieve such performance by exposure to potassium (K) vapor and device annealing in high vacuum. The treatment has a two-fold effect to: (i) controllably shift V_th toward negative gate biases via bulk doping of the nanotube (up to about 0.6e/nm), and (ii) increase the on-current by 1-2 orders of magnitude. This current enhancement is achieved by lowering external device resistance due to more intimate contact between K metal and doped nanotube channel in addition to potential reduction of the Schottky barrier height at the contact.

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M. Radosavljevic, J. Appenzeller, Ph. Avouris, J. Knoch. 2004-02-13. High performance n-doped carbon nanotube field-effect transistors. https://doi.org/10.1063/1.1737062

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