More than 10,000 carbon nanotube field-effect transistors(CNTFETs)have been successfully integrated into one semiconductor chip using conventional semiconductor design procedures and manufacturing processes.These tran...More than 10,000 carbon nanotube field-effect transistors(CNTFETs)have been successfully integrated into one semiconductor chip using conventional semiconductor design procedures and manufacturing processes.These transistors offer advantages such as high carrier mobility,large saturation velocity,low intrinsic capacitance,flexibility,and transparency.The three-dimensional multilayer structure of the CNTFET semiconductor chip,along with ongoing research in CNTFET manufacturing processes,increases the potential for creating a hybrid MOSFET-CNTFET semiconductor chip.This chip combines conventional metal-oxide-semiconductor field-effect transistors(MOSFETs)and CNTFETs in one integrated system.This paper discusses a methodology to design 6T binary static random-access memory(SRAM)using a hybrid MOSFET-CNTFET.This paper introduces a method for designing a hybrid MOSFET-CNTFET SRAM by leveraging existing MOSFET SRAM or CNTFET SRAM design approaches.Additionally,this paper compares its performance with conventional MOSFET SRAM and CNTFET SRAM designs.展开更多
A novel,carbon nanotubefield effect transistor(CNTFET)based fully differentialfirst order all passfilter(FDFAPF)circuit configuration is presented.The FDFAPF uses CNTFET based negative transconductors(NTs)and positive...A novel,carbon nanotubefield effect transistor(CNTFET)based fully differentialfirst order all passfilter(FDFAPF)circuit configuration is presented.The FDFAPF uses CNTFET based negative transconductors(NTs)and positive transconductors(PTs)in its realization.The proposed circuit topology employs two PTs,two NTs,two resistors and one capacitor.All the passive components of the realized topology are grounded.Active only fully differentialfirst order all passfilter(AO-FDFAPF)topology is also derived from the proposed FDFAPF.The electronic tunability of the AO-FDFAPF is obtained by controlling the employed CNTFET based varactor.A tunabilty of pole frequency in the range of 10.5 to 26 GHz is obtained.Both the circuits are potential candidates for high frequency fully differential analog signal processing applications.As compared to prior state-of-the-art works,both the realized topologies have achieved highest pole frequency and lowest power dissipation.Moreover,they utilize compact circuit structures and suitable for low voltage applications.Moreover,both topologies work equally well in the deep submicron.The proposedfilters are analyzed and verified through HPSPICE simulations by utilizing Stanford CNTFET model at 16 nm technology node.It is observed that the proposed circuit simulation outcomes verify the theory.展开更多
Carbon Nano-Tube Field Effect Transistors(CNTFETs) are being widely studied as possible successors to silicon MOSFETs.Using current mode has many advantages such as performing sum operation by means of a simple wired ...Carbon Nano-Tube Field Effect Transistors(CNTFETs) are being widely studied as possible successors to silicon MOSFETs.Using current mode has many advantages such as performing sum operation by means of a simple wired connection.Also,direction of the current can be used to exhibit the sign of digits.It is expected that the advantages of current mode approaches will become even more important with increased speed requirements and decreased supply voltage.In this paper,we present five new circuit designs for differential absolute value in current mode logic which have been simulated by CNTFET model.The considered base current for this model is 2 μA and supply voltage is 0.9 V.In all of our designs we used N-type CNTFET current mirrors which operate as truncated difference circuits.The operation of Differential Absolute Value circuit calculates the difference between two input currents and our circuit designs are operate in 8 logic levels.展开更多
This paper presents two new efficient ternary Full Adder cells for nanoelectronics. These CNTFETbased ternary Full Adders are designed based on the unique characteristics of the CNTFET device, such as the capability o...This paper presents two new efficient ternary Full Adder cells for nanoelectronics. These CNTFETbased ternary Full Adders are designed based on the unique characteristics of the CNTFET device, such as the capability of setting the desired threshold voltages by adopting proper diameters for the nanotubes as well as the same carrier mobilities for the N-type and P-type devices. These characteristics of CNTFETs make them very suitable for designing high-performance multiple-Vth structures. The proposed structures reduce the number of the transistors considerably and have very high driving capability. The presented ternary Full Adders are simulated using Synopsys HSPICE with 32 nm CNTFET technology to evaluate their performance and to confirm their correct operation.展开更多
A new carbon nanotube field effect transistor(CNTFET)based grounded active inductor(GAI)circuit is presented in this work.The suggested GAI offers a tunable inductance with a very wide inductive bandwidth,high quality...A new carbon nanotube field effect transistor(CNTFET)based grounded active inductor(GAI)circuit is presented in this work.The suggested GAI offers a tunable inductance with a very wide inductive bandwidth,high quality factor(QF)and low power dissipation.The tunability of the realized circuit is achieved through CNTFET based varactor.The proposed topology shows inductive behavior in the frequency range of 0.1–101 GHz and achieves to a maximum QF of 9125.The GAI operates at 0.7 V with 0.337 mW of power consumption.To demonstrate the performance of GAI,a broadband low noise amplifier(LNA)circuit is designed by utilizing the GAI based input matching-network.The realized LNA provides high frequency bandwidth(17.5–57 GHz),low noise figure(<3 dB)and occupies less space due to absence of any spiral inductor.Moreover,it exhibits a flat forward gain of 15.9 than±0.9 dB,a reverse isolation less than−63 dB and input return loss less−10 dB over the entire frequency bandwidth.The proposed CNTFET based GAI and LNA circuits are designed and verified by using HSPICE simulations with Stanford CNTFET model at 16 nm technology node.展开更多
Carbon nanotube field-effect transistors(CNTFETs) are reliable alternatives for conventional transistors, especially for use in approximate computing(AC) based error-resilient digital circuits. In this paper, CNTFET t...Carbon nanotube field-effect transistors(CNTFETs) are reliable alternatives for conventional transistors, especially for use in approximate computing(AC) based error-resilient digital circuits. In this paper, CNTFET technology and the gate diffusion input(GDI) technique are merged, and three new AC-based full adders(FAs) are presented with 6, 6, and 8 transistors, separately. The nondominated sorting based genetic algorithm II(NSGA-II) is used to attain the optimal performance of the proposed cells by considering the number of tubes and chirality vectors as its variables. The results confirm the circuits' improvement by about 50% in terms of power-delay-product(PDP) at the cost of area occupation. The Monte Carlo method(MCM) and 32-nm CNTFET technology are used to evaluate the lithographic variations and the stability of the proposed circuits during the fabrication process, in which the higher stability of the proposed circuits compared to those in the literature is observed. The dynamic threshold(DT) technique in the transistors of the proposed circuits amends the possible voltage drop at the outputs. Circuitry performance and error metrics of the proposed circuits nominate them for the least significant bit(LSB) parts of more complex arithmetic circuits such as multipliers.展开更多
A comparison of the CNTFET device with the MOSFET device in the nanometer regime is reported. The characteristics of both devices are observed as varying the oxide thickness. Thereafter, we have analyzed the effect of...A comparison of the CNTFET device with the MOSFET device in the nanometer regime is reported. The characteristics of both devices are observed as varying the oxide thickness. Thereafter, we have analyzed the effect of the chiral vector and the temperature on the threshold voltage of the CNTFET device. After simulation on the HSPICE tool, we observed that the high threshold voltage can be achieved at a low chiral vector pair. It is also observed that the effect of temperature on the threshold voltage of the CNTFET is negligibly small. After that, we have analyzed the channel length variation and their impact on the threshold voltage of the CNTFET as well as MOSFET devices. We found an anomalous effect from our simulation result that the threshold voltage increases with decreasing the channel length in CNTFET devices; this is contrary to the well known short channel effect. It is observed that at below the 10 nm channel length, the threshold voltage is increased rapidly in the case of the CNTFET device, whereas in the case of the MOSFET device, the threshold voltage decreases drastically.展开更多
The effects of linear doping profile near the source and drain contacts on the switching and high- frequency characteristics for conventional single-material-gate CNTFET （C-CNTFET） and hetero-material-gate CNTFET （...The effects of linear doping profile near the source and drain contacts on the switching and high- frequency characteristics for conventional single-material-gate CNTFET （C-CNTFET） and hetero-material-gate CNTFET （HMG-CNTFET） have been theoretically investigated by using a quantum kinetic model. This model is based on two-dimensional non-equilibrium Green＇s functions （NEGF） solved self-consistently with Poisson＇s equations. The simulation results show that at a CNT channel length of 20 nm with chirality （7, 0）, the intrinsic cutoff frequency of C-CNTFETs reaches up to a few THz. In addition, a comparison study has been performed between C-and HMG-CNTFETs. For the C-CNTFET, results reveal that a longer linear doping length can improve the cutoff frequency and switching speed. However, it has the reverse effect on on/off current ratios. To improve the on/off current ratios performance of CNTFETs and overcome short-channel effects （SCEs） in high-performance device applications, a novel CNTFET structure with a combination of an HMG and linear doping profile has been proposed. It is demonstrated that the HMG structure design with an optimized linear doping length has improved high-frequency and switching performances as compared to C-CNTFETs. The simulation study may be useful for understanding and optimizing high-performance of CNTFETs and assessing the reliability of CNTFETs for prospective applications.展开更多
This paper proposes a compact model for carbon nanotube field effect transistor（CNTFET） based on surface potential and conduction band minima. The proposed model relates the I–V characteristics to chirality under q...This paper proposes a compact model for carbon nanotube field effect transistor（CNTFET） based on surface potential and conduction band minima. The proposed model relates the I–V characteristics to chirality under quantum capacitance limit. C–V characteristics have been efficiently modelled for different capacitance models which are used to find the relationship between CNT surface potential and gate voltage. The role of different capacitances is discussed and it has been found that the proposed circuit compact model strictly follows quantum capacitance limit. The proposed model is efficiently designed for circuit simulations as it denies self-consistent numerical simulation. Furthermore, this compact model is compared with experimental results. The model has been used to simulate an inverter using HSPICE.展开更多
To overcome short-channel effects （SCEs） in high-performance device applications, a novel structure of CNTFET with a combination of halo and linear doping structure （HL-CNTFET） has been proposed. It has been theor...To overcome short-channel effects （SCEs） in high-performance device applications, a novel structure of CNTFET with a combination of halo and linear doping structure （HL-CNTFET） has been proposed. It has been theoretically investigated by a quantum kinetic model, which is based on two-dimensional non-equilibrium Green＇s functions solved self-consistently with Poisson＇s equations. We have studied the effect of halo doping and linear doping structure on static and dynamical performances of HL-CNTFET. It is demonstrated that a halo doping structure can decrease the drain leakage current and improve the on/off current ratio, and that linear doping can improve high-frequency and switching performance.展开更多
The method opted for accuracy,and no existing studies are based on this method.A design and characteristic survey of a new small band gap semiconducting Single Wall Carbon Nano Tube(SWCNT)Field Effect Transistor as a ...The method opted for accuracy,and no existing studies are based on this method.A design and characteristic survey of a new small band gap semiconducting Single Wall Carbon Nano Tube(SWCNT)Field Effect Transistor as a photodetector is carried out.In the proposed device,better performance is achieved by increasing the diameter and introducing a new single halo(SH)doping in the channel length of the CNTFET device.This paper is a study and analysis of the performance of a Carbon Nano Tube Field Effect Transistor(CNTFET)as a photodetector using the self-consistent Poisson and Green function method.The 2D self-consistent Poisson and Green’s function method for various optical intensities and wavelength simulate this proposed photodetector.The performance study is based on the simulation of drain current,transconductance,sub-threshold swing,cut-off frequency,gain,directivity,and quantum efficiency under dark and illuminated conditions.These quantum simulation results show that cut-off frequency increases while there is an increase in diameter.The proposed SH-CNTFET provides better performance in terms of higher gain and directivity than conventional CNTFET(C-CNTFET).This device will be helpful in optoelectronic integrated circuits(OEIC)receivers due to its superior performance.展开更多
基金supported by Seokyeong University in 2022.The EDA tool was supported by the IC Design Education Center(IDEC),Korea.
文摘More than 10,000 carbon nanotube field-effect transistors(CNTFETs)have been successfully integrated into one semiconductor chip using conventional semiconductor design procedures and manufacturing processes.These transistors offer advantages such as high carrier mobility,large saturation velocity,low intrinsic capacitance,flexibility,and transparency.The three-dimensional multilayer structure of the CNTFET semiconductor chip,along with ongoing research in CNTFET manufacturing processes,increases the potential for creating a hybrid MOSFET-CNTFET semiconductor chip.This chip combines conventional metal-oxide-semiconductor field-effect transistors(MOSFETs)and CNTFETs in one integrated system.This paper discusses a methodology to design 6T binary static random-access memory(SRAM)using a hybrid MOSFET-CNTFET.This paper introduces a method for designing a hybrid MOSFET-CNTFET SRAM by leveraging existing MOSFET SRAM or CNTFET SRAM design approaches.Additionally,this paper compares its performance with conventional MOSFET SRAM and CNTFET SRAM designs.
基金The authors would like to thank the Deanship of Scientific Research at Umm Al-QuraUniversity for supporting this work by Grant Code: (22UQU4320299DSR01).
文摘A novel,carbon nanotubefield effect transistor(CNTFET)based fully differentialfirst order all passfilter(FDFAPF)circuit configuration is presented.The FDFAPF uses CNTFET based negative transconductors(NTs)and positive transconductors(PTs)in its realization.The proposed circuit topology employs two PTs,two NTs,two resistors and one capacitor.All the passive components of the realized topology are grounded.Active only fully differentialfirst order all passfilter(AO-FDFAPF)topology is also derived from the proposed FDFAPF.The electronic tunability of the AO-FDFAPF is obtained by controlling the employed CNTFET based varactor.A tunabilty of pole frequency in the range of 10.5 to 26 GHz is obtained.Both the circuits are potential candidates for high frequency fully differential analog signal processing applications.As compared to prior state-of-the-art works,both the realized topologies have achieved highest pole frequency and lowest power dissipation.Moreover,they utilize compact circuit structures and suitable for low voltage applications.Moreover,both topologies work equally well in the deep submicron.The proposedfilters are analyzed and verified through HPSPICE simulations by utilizing Stanford CNTFET model at 16 nm technology node.It is observed that the proposed circuit simulation outcomes verify the theory.
文摘Carbon Nano-Tube Field Effect Transistors(CNTFETs) are being widely studied as possible successors to silicon MOSFETs.Using current mode has many advantages such as performing sum operation by means of a simple wired connection.Also,direction of the current can be used to exhibit the sign of digits.It is expected that the advantages of current mode approaches will become even more important with increased speed requirements and decreased supply voltage.In this paper,we present five new circuit designs for differential absolute value in current mode logic which have been simulated by CNTFET model.The considered base current for this model is 2 μA and supply voltage is 0.9 V.In all of our designs we used N-type CNTFET current mirrors which operate as truncated difference circuits.The operation of Differential Absolute Value circuit calculates the difference between two input currents and our circuit designs are operate in 8 logic levels.
基金supported by the Grant number 600/1792 from the vice presidency of research and technology of Shahid Beheshti University,G.C
文摘This paper presents two new efficient ternary Full Adder cells for nanoelectronics. These CNTFETbased ternary Full Adders are designed based on the unique characteristics of the CNTFET device, such as the capability of setting the desired threshold voltages by adopting proper diameters for the nanotubes as well as the same carrier mobilities for the N-type and P-type devices. These characteristics of CNTFETs make them very suitable for designing high-performance multiple-Vth structures. The proposed structures reduce the number of the transistors considerably and have very high driving capability. The presented ternary Full Adders are simulated using Synopsys HSPICE with 32 nm CNTFET technology to evaluate their performance and to confirm their correct operation.
基金The authors would like to thank the Deanship of Scientific Research at Umm Al-Qura University for supporting this work by Grant Code:(22UQU4320299DSR01).
文摘A new carbon nanotube field effect transistor(CNTFET)based grounded active inductor(GAI)circuit is presented in this work.The suggested GAI offers a tunable inductance with a very wide inductive bandwidth,high quality factor(QF)and low power dissipation.The tunability of the realized circuit is achieved through CNTFET based varactor.The proposed topology shows inductive behavior in the frequency range of 0.1–101 GHz and achieves to a maximum QF of 9125.The GAI operates at 0.7 V with 0.337 mW of power consumption.To demonstrate the performance of GAI,a broadband low noise amplifier(LNA)circuit is designed by utilizing the GAI based input matching-network.The realized LNA provides high frequency bandwidth(17.5–57 GHz),low noise figure(<3 dB)and occupies less space due to absence of any spiral inductor.Moreover,it exhibits a flat forward gain of 15.9 than±0.9 dB,a reverse isolation less than−63 dB and input return loss less−10 dB over the entire frequency bandwidth.The proposed CNTFET based GAI and LNA circuits are designed and verified by using HSPICE simulations with Stanford CNTFET model at 16 nm technology node.
文摘Carbon nanotube field-effect transistors(CNTFETs) are reliable alternatives for conventional transistors, especially for use in approximate computing(AC) based error-resilient digital circuits. In this paper, CNTFET technology and the gate diffusion input(GDI) technique are merged, and three new AC-based full adders(FAs) are presented with 6, 6, and 8 transistors, separately. The nondominated sorting based genetic algorithm II(NSGA-II) is used to attain the optimal performance of the proposed cells by considering the number of tubes and chirality vectors as its variables. The results confirm the circuits' improvement by about 50% in terms of power-delay-product(PDP) at the cost of area occupation. The Monte Carlo method(MCM) and 32-nm CNTFET technology are used to evaluate the lithographic variations and the stability of the proposed circuits during the fabrication process, in which the higher stability of the proposed circuits compared to those in the literature is observed. The dynamic threshold(DT) technique in the transistors of the proposed circuits amends the possible voltage drop at the outputs. Circuitry performance and error metrics of the proposed circuits nominate them for the least significant bit(LSB) parts of more complex arithmetic circuits such as multipliers.
文摘A comparison of the CNTFET device with the MOSFET device in the nanometer regime is reported. The characteristics of both devices are observed as varying the oxide thickness. Thereafter, we have analyzed the effect of the chiral vector and the temperature on the threshold voltage of the CNTFET device. After simulation on the HSPICE tool, we observed that the high threshold voltage can be achieved at a low chiral vector pair. It is also observed that the effect of temperature on the threshold voltage of the CNTFET is negligibly small. After that, we have analyzed the channel length variation and their impact on the threshold voltage of the CNTFET as well as MOSFET devices. We found an anomalous effect from our simulation result that the threshold voltage increases with decreasing the channel length in CNTFET devices; this is contrary to the well known short channel effect. It is observed that at below the 10 nm channel length, the threshold voltage is increased rapidly in the case of the CNTFET device, whereas in the case of the MOSFET device, the threshold voltage decreases drastically.
文摘The effects of linear doping profile near the source and drain contacts on the switching and high- frequency characteristics for conventional single-material-gate CNTFET （C-CNTFET） and hetero-material-gate CNTFET （HMG-CNTFET） have been theoretically investigated by using a quantum kinetic model. This model is based on two-dimensional non-equilibrium Green＇s functions （NEGF） solved self-consistently with Poisson＇s equations. The simulation results show that at a CNT channel length of 20 nm with chirality （7, 0）, the intrinsic cutoff frequency of C-CNTFETs reaches up to a few THz. In addition, a comparison study has been performed between C-and HMG-CNTFETs. For the C-CNTFET, results reveal that a longer linear doping length can improve the cutoff frequency and switching speed. However, it has the reverse effect on on/off current ratios. To improve the on/off current ratios performance of CNTFETs and overcome short-channel effects （SCEs） in high-performance device applications, a novel CNTFET structure with a combination of an HMG and linear doping profile has been proposed. It is demonstrated that the HMG structure design with an optimized linear doping length has improved high-frequency and switching performances as compared to C-CNTFETs. The simulation study may be useful for understanding and optimizing high-performance of CNTFETs and assessing the reliability of CNTFETs for prospective applications.
文摘This paper proposes a compact model for carbon nanotube field effect transistor（CNTFET） based on surface potential and conduction band minima. The proposed model relates the I–V characteristics to chirality under quantum capacitance limit. C–V characteristics have been efficiently modelled for different capacitance models which are used to find the relationship between CNT surface potential and gate voltage. The role of different capacitances is discussed and it has been found that the proposed circuit compact model strictly follows quantum capacitance limit. The proposed model is efficiently designed for circuit simulations as it denies self-consistent numerical simulation. Furthermore, this compact model is compared with experimental results. The model has been used to simulate an inverter using HSPICE.
文摘To overcome short-channel effects （SCEs） in high-performance device applications, a novel structure of CNTFET with a combination of halo and linear doping structure （HL-CNTFET） has been proposed. It has been theoretically investigated by a quantum kinetic model, which is based on two-dimensional non-equilibrium Green＇s functions solved self-consistently with Poisson＇s equations. We have studied the effect of halo doping and linear doping structure on static and dynamical performances of HL-CNTFET. It is demonstrated that a halo doping structure can decrease the drain leakage current and improve the on/off current ratio, and that linear doping can improve high-frequency and switching performance.
文摘The method opted for accuracy,and no existing studies are based on this method.A design and characteristic survey of a new small band gap semiconducting Single Wall Carbon Nano Tube(SWCNT)Field Effect Transistor as a photodetector is carried out.In the proposed device,better performance is achieved by increasing the diameter and introducing a new single halo(SH)doping in the channel length of the CNTFET device.This paper is a study and analysis of the performance of a Carbon Nano Tube Field Effect Transistor(CNTFET)as a photodetector using the self-consistent Poisson and Green function method.The 2D self-consistent Poisson and Green’s function method for various optical intensities and wavelength simulate this proposed photodetector.The performance study is based on the simulation of drain current,transconductance,sub-threshold swing,cut-off frequency,gain,directivity,and quantum efficiency under dark and illuminated conditions.These quantum simulation results show that cut-off frequency increases while there is an increase in diameter.The proposed SH-CNTFET provides better performance in terms of higher gain and directivity than conventional CNTFET(C-CNTFET).This device will be helpful in optoelectronic integrated circuits(OEIC)receivers due to its superior performance.
