Wafer-scalable, aligned carbon nanotube transistors operating at frequencies of over 100 GHz

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Wireless device technology operating in the millimetre-wave regime (30 to 300 GHz) increasingly needs to offer both high performance and a high level of integration with complementary metal–oxide–semiconductor (CMOS) technology. Aligned carbon nanotubes are proposed as an alternative to III–V technologies in such applications because of their highly linear signal amplification and compatibility with CMOS. Here we report the wafer-scalable fabrication of aligned carbon nanotube field-effect transistors operating at gigahertz frequencies. The devices have gate lengths of 110 nm and are capable, in distinct devices, of an extrinsic cutoff frequency and maximum frequency of oscillation of over 100 GHz, which surpasses the 90 GHz cutoff frequency of radio-frequency CMOS devices with gate lengths of 100 nm and is close to the performance of GaAs technology. Our devices also offer good linearity, with distinct devices capable of a peak output third-order intercept point of 26.5 dB when normalized to the 1 dB compression power, and 10.4 dB when normalized to d.c. power.

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Fig. 1: The technology evolution of RF CNT-FET devices.
Fig. 2: Aligned CNT arrays for RF-FET.
Fig. 3: aCNT-FET devices fabricated with a wafer-scalable process.
Fig. 4: D.c. and RF electrical performance of the 15 aCNT-FETs with highest self-gain from wafer 2.
Fig. 5: Linearity measurements of arrayed CNT-FETs.
Fig. 6: Benchmarking to incumbent RF technologies.

Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding author on reasonable request.


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This work was supported by King Abdulaziz City for Science and Technology (KACST) and The Saudi Technology Development and Investment Company (TAQNIA). Additional support was provided by the US Army STTR contract No. W911NF19P002. We also thank J. Blackburn for fruitful discussions and Qorvo, Inc. for providing a GaN FET device for validation testing.

Author information

C.R., A.A.K. and T.A.C. performed device fabrication. Analysis of the data was performed by A.A.K., P.F.M., C.R. and T.A.C. Electrical measurements were performed by P.F.M. Device simulation was performed by P.F.M., A.A.K. and B.I.H. Writing of the manuscript was performed by C.R., A.A.K., P.F.M. and T.A.C.. Technology development management and strategic technical planning were performed by C.R., K.G., C.Z. and M.R.A.

Correspondence to Christopher Rutherglen.

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Competing interests

The authors declare the following competing financial interest: C.R., A.A.K., P.F.M., T.A.C. and K.G. are employees of Carbonics Inc., a startup company focused on commercializing CNT transistors for microwave and millimetre-wave applications. C.Z. is a co-founder and shareholder of Carbonics Inc.

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Supplementary Sections 1–6, including figures and tables.

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Rutherglen, C., Kane, A.A., Marsh, P.F. et al. Wafer-scalable, aligned carbon nanotube transistors operating at frequencies of over 100 GHz. Nat Electron 2, 530–539 (2019) doi:10.1038/s41928-019-0326-y

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