title: Self-aligned T-gate high-purity semiconducting carbon nanotube RF transistors operated in quasi-ballistic transport and quantum capacitance regime.
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.
authors: Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089, USA.
authors: Yuchi
authors: Y
authors: Che
authors: Alexander
authors: A
authors: Badmaev
authors: Alborz
authors: A
authors: Jooyaie
authors: Tao
authors: T
authors: Wu
authors: Jialu
authors: J
authors: Zhang
authors: Chuan
authors: C
authors: Wang
authors: Kosmas
authors: K
authors: Galatsis
authors: Hani A
authors: HA
authors: Enaya
authors: Chongwu
authors: C
authors: Zhou
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D025802:Electric Capacitance; D004579:Electron Transport; D004867:Equipment Design; D019544:Equipment Failure Analysis; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D011789:Quantum Theory; D011846:Radio Waves; D012666:Semiconductors; D014173:Transistors, Electronic
chemical_list: D037742:Nanotubes, Carbon; D000537:Aluminum Oxide