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Updated: May 20, 2026

Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping
Published on: June 3, 2015
Self-aligned T-gate high-purity semiconducting carbon nanotube RF transistors operated in quasi-ballistic transport
Yuchi Che1, Alexander Badmaev, Alborz Jooyaie
1Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089, USA.
Abstract:
Carbon nanotube RF transistors are predicted to offer good performance and high linearity when operated in the ballistic transport and quantum capacitance regime; however, realization of such transistors has been very challenging. In this paper, we introduce a self-aligned fabrication method for carbon nanotube RF transistors, which incorporate a T-shaped (mushroom-shaped) aluminum gate, with oxidized aluminum as the gate dielectric. In this way, the channel length can be scaled down to 140 nm, which enables quasi-ballistic transport, and the gate dielectric is reduced to 2-3 nm aluminum oxide, leading to quasi-quantum capacitance operation. A current-gain cutoff frequency (f(t)) up to 23 GHz and a maximum oscillation frequency (f(max)) of 10 GHz are demonstrated. Furthermore, the linearity properties of nanotube transistors are characterized by using the 1 dB compression point measurement with positive power gain for the first time, to our knowledge. Our work reveals the importance and potential of separated semiconducting nanotubes for various RF applications.
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