scholarly journals Device design and optimization of CNTFETs for high-frequency applications

2021 ◽  
Author(s):  
Boli Peng ◽  
Manojkumar Annamalai ◽  
Sven Mothes ◽  
Michael Schröter
Keyword(s):  
High Frequency ◽  
Design Space ◽  
Field Effect Transistors ◽  
Device Design ◽  
Design And Optimization ◽  
Figures Of Merit ◽  
Device Architecture ◽  
Unit Cells ◽  
Minimal Contact ◽  
Tube Density

AbstractCarbon nanotube (CNT) field-effect transistors (FETs) have recently reached high-frequency (HF) performance similar to that of silicon RF-CMOS at the same gate length despite a tube density and current per tube that are far from the physical limits and suboptimal device architecture. This work reports on an investigation of the optimal device design for practical HF applications in terms of cut-off frequencies, power gain, and linearity. Different fundamental designs in the gate contact arrangement are considered based on a 3D device simulation of both CNTs and contacts. First, unit cells with a single CNT and minimal contact sizes are compared. The resulting simulation data are then extended toward a structure with two gate fingers and realistic contact sizes. Corresponding parasitic capacitances, as well as series and contact resistances, have been included for obtaining realistic characteristics and figures of merit that can be used for comparison with corresponding silicon RF MOSFETs. Finally, a sensitivity analysis of the device architecture with the highest performance is performed in order to find the optimal device design space.

scholarly journals High-Frequency Capability of Schottky-Barrier Carbon Nanotube FETs

2007 ◽  
Vol 121-123 ◽  
pp. 693-696 ◽  
Author(s):  
Leonardo C. Castro ◽  
D.L. Pulfrey ◽  
D.L. John
Keyword(s):  
Carbon Nanotube ◽  
Schottky Barrier ◽  
High Frequency ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Schottky Contacts ◽  
Small Signal ◽  
Gate Electrode ◽  
Figures Of Merit ◽  
Significant Bias

The high-frequency capability of carbon nanotube field-effect transistors is investigated by simulating the small-signal performance of a device with negative-barrier Schottky contacts for the source and drain, and with a small, ungated region of nanotube between the end contacts and the edge of the wrap-around gate electrode. The overall structure is shown to exhibit resonant behaviour, which leads to a significant bias dependence of the small-signal capacitances and transconductance. This could lead to high-frequency figures of merit (fT and fmax) in the terahertz regime.

High-frequency equivalent circuits of junction-gate field-effect transistors

1970 ◽  
Vol 6 (18) ◽  
pp. 590
Author(s):  
P.U. Calzolari ◽  
S. Graffi ◽  
A. Mazzone
Keyword(s):  
High Frequency ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Equivalent Circuits

scholarly journals Figures of merit in high-frequency and high-power GaN HEMTs

2009 ◽  
Vol 193 ◽  
pp. 012040 ◽  
Author(s):  
F A Marino ◽  
N Faralli ◽  
D K Ferry ◽  
S M Goodnick ◽  
M Saraniti
Keyword(s):  
High Power ◽  
High Frequency ◽  
Figures Of Merit ◽  
Gan Hemts

scholarly journals Numerical Evaluation of the Effect of Geometric Tolerances on the High-Frequency Performance of Graphene Field-Effect Transistors

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3121
Author(s):  
Monica La Mura ◽  
Patrizia Lamberti ◽  
Vincenzo Tucci
Keyword(s):  
High Frequency ◽  
Communication Systems ◽  
Field Effect ◽  
Field Effect Transistor ◽  
Field Effect Transistors ◽  
Channel Length ◽  
Geometrical Parameters ◽  
Effect Transistor ◽  
Rf Performance ◽  
The Impact

The interest in graphene-based electronics is due to graphene’s great carrier mobility, atomic thickness, resistance to radiation, and tolerance to extreme temperatures. These characteristics enable the development of extremely miniaturized high-performing electronic devices for next-generation radiofrequency (RF) communication systems. The main building block of graphene-based electronics is the graphene-field effect transistor (GFET). An important issue hindering the diffusion of GFET-based circuits on a commercial level is the repeatability of the fabrication process, which affects the uncertainty of both the device geometry and the graphene quality. Concerning the GFET geometrical parameters, it is well known that the channel length is the main factor that determines the high-frequency limitations of a field-effect transistor, and is therefore the parameter that should be better controlled during the fabrication. Nevertheless, other parameters are affected by a fabrication-related tolerance; to understand to which extent an increase of the accuracy of the GFET layout patterning process steps can improve the performance uniformity, their impact on the GFET performance variability should be considered and compared to that of the channel length. In this work, we assess the impact of the fabrication-related tolerances of GFET-base amplifier geometrical parameters on the RF performance, in terms of the amplifier transit frequency and maximum oscillation frequency, by using a design-of-experiments approach.

scholarly journals Design Space Identification and Visualization for Continuous Pharmaceutical Manufacturing

Pharmaceutics ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 235 ◽  
Author(s):  
Samir Diab ◽  
Dimitrios I. Gerogiorgis
Keyword(s):  
Design Space ◽  
Flow Chemistry ◽  
Pharmaceutical Manufacturing ◽  
Design And Optimization ◽  
Pharmaceutical Ingredients ◽  
Continuous Pharmaceutical Manufacturing ◽  
Continuous Flow Chemistry ◽  
Material Usage ◽  
Novel Processing ◽  
Insight Into

Progress in continuous flow chemistry over the past two decades has facilitated significant developments in the flow synthesis of a wide variety of Active Pharmaceutical Ingredients (APIs), the foundation of Continuous Pharmaceutical Manufacturing (CPM), which has gained interest for its potential to reduce material usage, energy and costs and the ability to access novel processing windows that would be otherwise hazardous if operated via traditional batch techniques. Design space investigation of manufacturing processes is a useful task in elucidating attainable regions of process performance and product quality attributes that can allow insight into process design and optimization prior to costly experimental campaigns and pilot plant studies. This study discusses recent demonstrations from the literature on design space investigation and visualization for continuous API production and highlights attainable regions of recoveries, material efficiencies, flowsheet complexity and cost components for upstream (reaction + separation) via modeling, simulation and nonlinear optimization, providing insight into optimal CPM operation.

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