Theoretical calculations predict transition frequencies in the terahertz range for the field-effect transistors based on carbon nanotubes, and this shows their suitability for being used in high frequency applications...Theoretical calculations predict transition frequencies in the terahertz range for the field-effect transistors based on carbon nanotubes, and this shows their suitability for being used in high frequency applications. In this paper, we have designed a field-effect transistor based on carbon nanotube with high transition frequency suitable for ultra-wide band applications. We did this by optimizing nanotube diameter, gate insulator thickness and dielectric constant. As a result, we achieved the transition frequency about 7.45 THz. The environment of open source software FETToy is used to simulate the device. Also a suitable model for calculating the transition frequency is presented.展开更多
The design of a three-input logic circuit using carbon nanotube field effect transistors(CNTFETs)is presented.Ternary logic must be an exact replacement for dual logic since it performs straightforwardly in digital de...The design of a three-input logic circuit using carbon nanotube field effect transistors(CNTFETs)is presented.Ternary logic must be an exact replacement for dual logic since it performs straightforwardly in digital devices,which is why this design is so popular,and it also reduces chip area,both of which are examples of circuit overheads.The proposed module we have investigated is a triple-logic-based one,based on advanced technology CNTFETs and an emphasis on minimizing delay times at various values,as well as comparisons of the design working with various load capacitances.Comparing the proposed design with the existing design,the delay times was reduced from 66.32 to 16.41 ps,i.e.,a 75.26%reduction.However,the power dissipation was not optimized,and increased by 1.44%compared to the existing adder.The number of transistors was also reduced,and the product of power and delay(P∗D)achieved a value of 0.0498053 fJ.An improvement at 1 V was also achieved.A load capacitance(fF)was measured at different values,and the average delay measured for different values of capacitance had a maximum of 83.60 ps and a minimum of 22.54 ps,with a range of 61.06 ps.The power dissipations ranged from a minimum of 3.38μW to a maximum of 6.49μW.Based on these results,the use of this CNTFET half-adder design in multiple Boolean circuits will be a useful addition to circuit design.展开更多
5-hydroxymethylcytosine （5-hmC） is an important epigenetic derivative of cytosine and quantitative detection of 5-hmC could be used as a reliable biomarker for a variety of human diseases. Current technologies used ...5-hydroxymethylcytosine （5-hmC） is an important epigenetic derivative of cytosine and quantitative detection of 5-hmC could be used as a reliable biomarker for a variety of human diseases. Current technologies used in 5-hmC detection are complicated and time/cost inefficient. In this work, we report the first application of antibody-functionalized carbon nanotube field-effect transistors （CNT-FETs） in quantitative detection of 5-hmC from mouse tissues. This method achieves facile and ultra-sensitive 5-hmC detection based on electrical performance device and avoids complicated processing for DNA samples. The 5-hmC content percentages of normal mouse cerebrum, cerebellum, spleen, lung, liver, and heart samples presented in the genomic DNA were measured as 0.653, 0.573, 0.002, 0.020, 0.076, and 0.009, respectively, which is consistent with previous reports. This technology could be developed into fadle routine 5-hmC monitoring devices for clinic human disease diagnoses.展开更多
Carbon nanotube field-effect transistors(CNTFETs)are increasingly recognized as a viable option for creating high-performance,low-power,and densely integrated circuits(ICs).Advancements in carbon-based electronics,enc...Carbon nanotube field-effect transistors(CNTFETs)are increasingly recognized as a viable option for creating high-performance,low-power,and densely integrated circuits(ICs).Advancements in carbon-based electronics,encompassing materials and device technology,have enabled the fabrication of circuits with over 1000 gates,marking carbon-based integrated circuit design as a burgeoning field of research.A critical challenge in the realm of carbon-based very-large-scale integration(VLSI)is the lack of suitable automated design methodologies and infrastructure platforms.In this study,we present the development of a waferscale 3μm carbon-based complementary metal-oxide-semiconductor(CMOS)process design kit(PDK)(3μm-CNTFETs-PDK)compatible with silicon-based Electronic Design Automation(EDA)tools and VLSI circuit design flow.The proposed 3μm-CNTFETs-PDK features a contacted gate pitch(CGP)of 21μm,a gate density of 128 gates/mm^(2),and a transistor density of 554 transistors/mm^(2),with an intrinsic gate delay around 134 ns.Validation of the 3μm-CNTFETs-PDK was achieved through the successful design and tape-out of 153 standard cells and 333-stage ring oscillator circuits.Leveraging the carbon-based PDK and a silicon-based design platform,we successfully implemented a complete 64-bit static random-access memory(SRAM)circuit system for the first time,which exhibited timing,power,and area characteristics of clock@10 kHz,122.1μW,3795μm×2810μm.This research confirms that carbon-based IC design can be compatible with existing EDA tools and silicon-based VLSI design flow,thereby laying the groundwork for future carbon-based VLSI advancements.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
文摘Theoretical calculations predict transition frequencies in the terahertz range for the field-effect transistors based on carbon nanotubes, and this shows their suitability for being used in high frequency applications. In this paper, we have designed a field-effect transistor based on carbon nanotube with high transition frequency suitable for ultra-wide band applications. We did this by optimizing nanotube diameter, gate insulator thickness and dielectric constant. As a result, we achieved the transition frequency about 7.45 THz. The environment of open source software FETToy is used to simulate the device. Also a suitable model for calculating the transition frequency is presented.
文摘The design of a three-input logic circuit using carbon nanotube field effect transistors(CNTFETs)is presented.Ternary logic must be an exact replacement for dual logic since it performs straightforwardly in digital devices,which is why this design is so popular,and it also reduces chip area,both of which are examples of circuit overheads.The proposed module we have investigated is a triple-logic-based one,based on advanced technology CNTFETs and an emphasis on minimizing delay times at various values,as well as comparisons of the design working with various load capacitances.Comparing the proposed design with the existing design,the delay times was reduced from 66.32 to 16.41 ps,i.e.,a 75.26%reduction.However,the power dissipation was not optimized,and increased by 1.44%compared to the existing adder.The number of transistors was also reduced,and the product of power and delay(P∗D)achieved a value of 0.0498053 fJ.An improvement at 1 V was also achieved.A load capacitance(fF)was measured at different values,and the average delay measured for different values of capacitance had a maximum of 83.60 ps and a minimum of 22.54 ps,with a range of 61.06 ps.The power dissipations ranged from a minimum of 3.38μW to a maximum of 6.49μW.Based on these results,the use of this CNTFET half-adder design in multiple Boolean circuits will be a useful addition to circuit design.
文摘5-hydroxymethylcytosine （5-hmC） is an important epigenetic derivative of cytosine and quantitative detection of 5-hmC could be used as a reliable biomarker for a variety of human diseases. Current technologies used in 5-hmC detection are complicated and time/cost inefficient. In this work, we report the first application of antibody-functionalized carbon nanotube field-effect transistors （CNT-FETs） in quantitative detection of 5-hmC from mouse tissues. This method achieves facile and ultra-sensitive 5-hmC detection based on electrical performance device and avoids complicated processing for DNA samples. The 5-hmC content percentages of normal mouse cerebrum, cerebellum, spleen, lung, liver, and heart samples presented in the genomic DNA were measured as 0.653, 0.573, 0.002, 0.020, 0.076, and 0.009, respectively, which is consistent with previous reports. This technology could be developed into fadle routine 5-hmC monitoring devices for clinic human disease diagnoses.
基金The authors gratefully acknowledge fundings from the Strategic Priority Research Program of Chinese Academy of Sciences(CAS)(No.XDA0330401)CAS Youth Interdisciplinary Team(No.JCTD-2022-07).
文摘Carbon nanotube field-effect transistors(CNTFETs)are increasingly recognized as a viable option for creating high-performance,low-power,and densely integrated circuits(ICs).Advancements in carbon-based electronics,encompassing materials and device technology,have enabled the fabrication of circuits with over 1000 gates,marking carbon-based integrated circuit design as a burgeoning field of research.A critical challenge in the realm of carbon-based very-large-scale integration(VLSI)is the lack of suitable automated design methodologies and infrastructure platforms.In this study,we present the development of a waferscale 3μm carbon-based complementary metal-oxide-semiconductor(CMOS)process design kit(PDK)(3μm-CNTFETs-PDK)compatible with silicon-based Electronic Design Automation(EDA)tools and VLSI circuit design flow.The proposed 3μm-CNTFETs-PDK features a contacted gate pitch(CGP)of 21μm,a gate density of 128 gates/mm^(2),and a transistor density of 554 transistors/mm^(2),with an intrinsic gate delay around 134 ns.Validation of the 3μm-CNTFETs-PDK was achieved through the successful design and tape-out of 153 standard cells and 333-stage ring oscillator circuits.Leveraging the carbon-based PDK and a silicon-based design platform,we successfully implemented a complete 64-bit static random-access memory(SRAM)circuit system for the first time,which exhibited timing,power,and area characteristics of clock@10 kHz,122.1μW,3795μm×2810μm.This research confirms that carbon-based IC design can be compatible with existing EDA tools and silicon-based VLSI design flow,thereby laying the groundwork for future carbon-based VLSI advancements.
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.
