Carbon Nanotube Fet



We have investigated the high frequency electrical properties of single-walled carbon nanotube field effect transistors by operating the devices as microwave mixers. The mixing current amplitude depends linearly on the transconductance and quadratically on the applied AC voltage. On devices with insulating substrates, the response is approximately independent of frequency up to 40 GHz.

Description:

  1. Carbon Nanotube Field Effect Transistor (CNT FET) Technology to Support National Security Space System Applications Supporting/Contributing Agencies: National Reconnaissance Office A critical need exists to improve satellite receiver front end performance for a variety of applications that include communications, imaging and signal acquisition.
  2. Field-effect transistors (FETs) based on moderate or large diameter carbon nanotubes (CNTs) usually suffer from ambipolar behavior, large off-state current and small current on/off ratio, which are highly undesirable for digital electronics. To overcome these problems, a feedback-gate (FBG) FET structure is designed and tested.

TECHNOLOGY AREA(S): Info Systems

Carbon nanotube fetal

OBJECTIVE: Demonstrate the superiority of Carbon Nanotube Field-Effect Transistor (CNTFET) device and circuit performance over CMOS for RF applications

DESCRIPTION: CNTFET technology has the potential for integrating high-frequency (HF) (10–40 GHz) electronics as well as mechanical switches and oscillators along with high-performance digital signal processing and possibly even mm-wave sensing, all integrated on a single low-power all carbon nanotube (CNT) chip. Low power at high frequencies is achieved, among others, by the linearity of the CNTFETs. More recently CNTFET cut-off frequencies close to those of CMOS have been reported (for the relaxed channel lengths that can be reliably fabricated in research labs) despite the several technology related factors that presently limit the CNTFET performance. E.g., the number of CNTs per channel width (i.e. CNT density) and the current per CNT are just a fraction of the theoretical maximum number. While the improvement of the underlying limiting factors is already being addressed by materials and fabrication related research projects, it is presently unclear, under which structural conditions CNTFETs will start outperforming Si-MOSFETs. Structural conditions are, e.g., CNT density and current, contact resistance, as well as device layout and contact arrangement (such as top gate, bottom gate, double gate etc.).This solicitation calls for the detailed investigation of CNTFET device design and its impact on HF circuit performance in comparison to Si-MOSFETs and related circuits at the same channel lengths.

PHASE I: Establish a geometry scalable CNTFET compact model for HF circuit design and determine its parameters on fabricated devices. The structural conditions of the baseline CNTFET are adjusted to the best presently existing hardware. Scale the model to 130nm channel length and compare the HF device performance to widely used 130nm RF Si-CMOS, including all known parasitic effects. Make stepwise improvements of the structural conditions and device design to determine (a) the conditions for breaking even with CMOS and (b) the best CNTFET performance that can be expected. The outcome will be a compact model that will guide the design of practical CNTFET circuits and accelerate the development of commercial transistors based on this unique technology.

PHASE II: Based on the CNTFET compact model, design the key circuit blocks of transceiver front-ends at different frequencies: low-noise amplifier, mixer, oscillator, and power amplifier. Use ideal passives to be able to benchmark CNTFET vs. Si-MOSFET device performance. The goal is to demonstrate the superiority of scaled CNTFET technology over Si-CMOS for 5G and similar complex RF applications.

Carbon Nanotube Fett

PHASE III: Fabricate CNTFETs along with the designed transceiver front-end circuits and perform experimental verification to simulation (with realistic passives). DUAL USE APPLICATIONS: The CNTFETs and circuits can be used in both wireless communication systems and sensor systems such as biological and chemical sensing, operating at the lowest possible power dissipation. The selected company can further pursue for CNTFET space-qualifying prototyping and complete radiation qualification testing for potential inclusion in test flight, communications and sensing applications

REFERENCES:

1: Yu Cao,Gerald J. Brady, Hui Gui, Chris Rutherglen, Michael S. Arnold, and Chongwu Zhou 'Radio Frequency Transistors Using Aligned Semiconducting Carbon Nanotubes with Current-Gain Cutoff Frequency and Maximum Oscillation Frequency Simultaneously Greater than 70 GHz' ACS Nano, 2016, 10 (7), pp 6782–6790 Publication Date (Web): June 21, 2016

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2: Yu Cao, Yuchi Che, Hui Gui, Xuan Cao, and Chongwu Zhou. 'Radio frequency transistors based on ultra-high purity semiconducting carbon nanotubes with superior extrinsic maximum oscillation frequency' Nano Res. (2016) 9: 36 https://doi.org/10.1007/s12274-015-0915-7

Carbon Nanotube Fete

3: Y. Cao, G. Brady, H. Gui, C. Rutherglen, M. Arnold, Z. Zhou, 'Radio frequency transistors using aligned semiconducting carbon nanotubes with current gain cutoff frequency and maximum oscillation frequency simultaneous greater than 70 GHz', ACS Nano, Vol. , No., pp. -, 201

4: S. Mothes, M. Claus, and M. Schroter, 'Toward linearity in Schottky barrier CNTFETs', IEEE Transactions On Nanotechnology, 14, pp372-378 (2015).

Carbon

KEYWORDS: Carbon Nanotube, CNT, Carbon Nanotube Field Effect Transistor, CNTFET, RF Front-end Circuits, Transceiver, Schottky Barrier

Cnt Fet Doping

FetCarbon nanotube fetus

CONTACT(S):

Carbon Nanotube Fetal Alcohol Syndrome

Daniel McCarthy

(315) 330-2519

Carbon Nanotube Fet

daniel.mccarthy.9@us.af.mil