Finally, conclusions and remarks are reported in section vii. Request pdf cntfet basics and simulation this paper provides an overview of current types of cntfets and of some compact models. Review of cntfet since 1991 which carbon nanotube was discovered by iijima 12 it has been studied in a wide field of science and also in nanoelectronic. Abstract we start with basic terminology and concepts of modeling, and decompose the art of modeling as a process. Sep 07, 2006 cntfet basics and simulation abstract. This overview of the process helps clarify when we should or should not use simulation models. Modeling undeposited cnts for high performance design and. The performances such as delay, power and the transient results of the cntfet comparator simulation are much more efficient. The comparison of results indicated that the proposed 10nm cntfet based design is more efficient in power savings and speed. Hence, it is analyzed that cntfet based circuits are energy efficient. This dissertation first suggests cntfet circuit design methods to fairly compare the performance between mosfet and cntfet by considering pdp, leakage, and pvt variations. Pdf design and analysis of cntfet based d flipflop iaeme. A whereas a cntfet of chirality 17 at the same electrical conditions produces a current of 7.
The simulation shows high performance at low power voltage supply. The role of debriefing in simulation based learning. Finally, the proposed designs are compared with the stateoftheart ternary designs. Table 1 device parameters for simulation cntfet model oxide thickness 4 nm cnt diameter 1. A cntfet, whether planar or coaxial, relies on similar principles, while being governed by additional phenomena such as 1d density of states dos and ballistic transport.
Using the available models, the influence of the parameters on the device characteristics was simulated and analyzed. Cntfet sb cntfet 4, the conventional cntfet c cntfet featuring a doping profile similar to nmosfet 5, the dualgate cntfet exhibits n or ptype unipolar behavior tunable by electrostatic doping 6 and the tunneling cntfet 7. Modeling undeposited cnts for high performance design and the. The obvious advantage of md over mc is that it gives a route to dynamical properties of the system. Cntfet with channel length10nm and chiral vectorm0,n fig. Cntfet is found to be one of the most promising alternatives for mosfet. Hence, considering a single walled, semiconducting carbon nanotube as the channel of a cntfet including source, drain, gate electrodes, the.
Cntfet basics and simulation ieee conference publication. Simulation results have shown that these circuits have low power dissipation and high performance and therefore, outperform their cmos counterparts. Implementation of mod16 counter using veriloga model of. Quantum capacitance vs gate voltage with varying oxide thickness 11. Design, simulation and comparative analysis of cnt based. In other words, this project is focused on the simulation of carbon nanotube fieldeffect transistors cntfet with the ternary design and benchmark with binary design. Static simulation of cntfet based digital circuits roberto marani1 and anna gina perri2, 1consiglio nazionale delle ricerche, istituto di studi sui sistemi intelligenti per lautomazione issia, bari, italy.
Pdf cntfet modeling and reconfigurable logiccircuit design. This work is based on a numerical simulation program based on surface potential model. Sb cntfet is defined as a device where the electrons are tunnelled through sb. Introduction for many years, vlsi chip designers have been using metaloxide semiconductor fieldeffect transistors mosfets as basic circuit elements. Jul 10, 2014 10 continues from the analysis and simulation, it was observed that quantum capacitance varies with gate voltage for different oxide thickness in cntfet. Carbon nanotube carbon is an element with symbol c and atomic number 6 1s22s22p2. Cntfet modeling and performance analysis of device characteristics. The xor gate is implemented using only three transistors. The simulation result of cntfet and cmos is compared parameters like propagation delay, power consumption and power delay product is also compared.
Unlike finfets, cntfet s are ballistic devices with high mobility carbon nano tube cnt as channel. Kong, springer, 2007 device simulation of swntfets jing guo1 and mark lundstrom2 1 department of electrical and computer engineering, university of flor ida, gainesville, fl, 32611 2 school of electrical and computer engineering, purdue university, west lafayette, in, 47907 1 introduction. Cntfets carbon nanotube field effect transistors are novel devices that. The introduction starts with a definition of simulation, goes through a talk. It has the ability to minimize subthreshold slope and hence sces. Design of cntfet based digital logic and arithmetic. The basic assumption here is mosfet like cntfet, where the schottky. Simulations of enhanced cntfet with hfo2 gate dielectric.
Design methodology based on carbon nanotube field effect. And fall time for classical and cntfet comparators are 821. Introduction throughout the past few decades, the semiconductor engineering has witnessed enormous performance developments and shrivelling in device geometries. Its n structure albeit simple provides a behavior like. Hspice simulation of d latch and double edge triggered. Digital circuit simulation using hspice 3 vbb 2 0 dc 2v 5 input signal 6 vin 3 0 pwl 0ns 0v 0. Cntfet basics and simulation request pdf researchgate. Pdf modelling, simulation and characteristics of cntfets. Modeling and simulation of ntype carbon nanotube field effect transistors using. All the aspects which are important in performance analysis of cntfet are discussed. Design and simulation of basic logic circuits model of cntfet and ptype and ntype cntfet can be using cntfet obtained by only altering the polarity of the polarity gate pg we have designed an inverter circuit as shown in fig. Since most simulation results are essentially random variables, it may be hard to determine whether an observation is a result of system interrelationships or just randomness. Section 3 comprises of some simulation results for planar cntfet. The model, based on the hypothesis of fully ballistic transport in a mesoscopic system between two nonreflective contacts, has been structured to allow an easy implementation in veriloga language and has been compared with experimental data, showing a good.
A detailed simulation based assessment of the circuit performance of cntfets is presented and compared to conventional mosfets. Tunneling carbon nanotube field effect transistor with. After simulation, it is shown that cntfet offers better results for ionioff on the order of 10. Pdf cntfet modeling and reconfigurable logiccircuit. Carbon nano tube field effect transistor cntfetcntfet is a type of fieldeffect transistor that utilizes single wall carbon nano tubes swcnts as the channel material instead of bulk silicon used in the traditional mosfet structure. Hspice simulation of d latch and double edge triggered flip. Basic principle operation of cnfet is the same as mosfet where electrons are supplied. An equivalent circuit model of a ballistic onedimension cntfet has been introduced for circuit simulation, as illustrated in figure 3. Comparative analysis of cntfet and cmos logic based. Cmos, cnt, cntfet, tristate buffer, mux, simulation i. The potential of vlsi circuits lies in more and more channel. Cntfet based design, modelling, digital circuits, cad. From figure 4, at 300k for a cntfet of chirality the drain current for a gate voltage of 0.
These devices show the ballistic transport in the current conduction. Design and comparative analysis of cntfet based tristate. The cntfet simulation will be carried out by cntfet lab tool of nano 4 which is an online based java platform engine. Simulations of carbon nanotube field effect transistors. Introduction since the first reports of singlewalled carbon nanotubes cnts in 1993,1,2 they have been the subject of intense interest for basic. It is important to know the characteristics of a single cnt based transistor. First carbon nanotubes cnts and importance of cnt over silicon based devices has been discussed, and then basics of ternary logic have been explained. Increasing cnt diameter has good effect on cntfet as seen from results. Simulation and analysis of cntfets based logic gates in. The diameter of the cnt is given by the formuladcntch. University of pittsburgh medical center upmc and the peter m. To verify the validity of the obtained results, they are compared with those of wong model, obtaining results in good agreement, but with a lighter ensuring compile and a shorter execution time. So, to obtain predictive circuit simulation results, it is mandatory to precisely understand transport phenomena in cntfet at the molecular scale. The power consumption of cntfet based alu is found to be 45.
This introduction to simulation tutorial is designed to teach the basics of simulation, including structure, function, data generated, and its proper use. Jan 01, 2015 cntfet basics and simulation, international conference design and test of integrated systems in nanoscale technology. Depicts the density vs distance plot of cntfet fig 6c fig. Section6 summarizes the paper and shows future prospects of cntfets usage. In this paper, a veriloga formulation of the stanford compact model is used for the simulation of different logic gates in cadence and finally mod16 counter. The transient and power analyses in this paper are obtained with operating voltage at 0. Predictive cntfet models are also proposed in 1214 that can be used in circuit design and simulation. Dft based estimation of cnt parameters and simulationstudy. Carbon nanotube field effect transistor cntfet, mosfet, cadence, comparator, delay and power. Wong, a circuitcompatible spice model for enhancement mode carbon nanotube field effect transistors, proc. Proposed designs and simulation results of logic gates basic functions such as and, or. Accurate spice compatible cnt interconnect and cntfet.
Winter institute for simulation, education and research wiser pittsburgh, pa. The basic electrical properties such as band structure, density of. Keywords cntfet, mosfet, chirality, graphene, 6t sram i. The basic building block of adder is xor gate is shown in fig. Jun 01, 2018 cntfet based biochips could be exploited in developing portable devices that are integrated and highly throughput producing. Pdf modeling and simulation of carbon nanotube field. A comparative study of csa design using cntfet and mosfet. Simulation and analysis of cntfets based logic gates in hspice.
The proposed alu is simulated using monte carlo simulation at 0. Finally, using the proposed cntfet circuit design and evaluation method, a methodology to design a novel ternary cntfet sram cell is proposed and its performance is evaluated compared to a binary mosfet and cntfet based sram cells with undeposited cnts. First demonstrated in 1998, there have been major developments in cntfets since. In this paper the standard model has been designed for, mosfet like cntfet devices. Cntfet basics and simulation ieee conference publication ieee. Cntfet technology provides more efficient way to implement these functions in terms of delay and power consumption. Basic principle operation of cnfet is the same as mosfet where electrons are supplied by source terminal and drain terminal will collect these electrons. Cntfet has capability to use as a future nanoscale transistor.
Simulation of logic gates is performed using cntfets and comparison is done by changing various parameters. Pdf on may 5, 20, rambabu busi published modelling, simulation and characteristics of cntfet s find, read and cite all the research you need on researchgate. Section 5 typical analogue circuits and logic blocks have been simulated b. In this work, cntfet based cascode otas have been designed and simulated using hspice at the 45nm technology node. In this paper we present an exhaustive description of the basic types of cntfets. Ternary logic design later to be verified the performance and correctness using arithmetic circuit. International journal of soft computing and engineering.
A carbon nanotube fieldeffect transistor cntfet refers to a fieldeffect transistor that utilizes a single carbon nanotube or an array of carbon nanotubes as the channel material instead of bulk silicon in the traditional mosfet structure. A veriloga compact model for carbon nanotube field effect transistors cntfets has been implemented to study basic digital circuits. Carbon nanotube field effect transistor cntfet and. The observed results reveal that cntfet has potential to replace cmos for low power and high performance applications in near future. Design of cntfet based digital logic and arithmetic circuits. From the simulated output waveform we can observe that if either inputs or any one of the input is low then the output is high otherwise the output is low.
Since conventional n and p channel mosfets are also involved, the bsimv4. A swcnt is a nanotube formed by rolling a single sheet of graphite. Different types of cntfet s are proposed since the invention of cnts. The simulation study invokes veriloga stanford models of cntfet in the design and simulation of cntbased cotas. The presentation of the paper is organized as follows. Simulation is a powerful tool if understood and used properly. Table given below shows the summary of simulation results. Hspice simulation of d latch and double edge triggered flipflop using cntfet 1deepak v. One of the basic ideas is to replace the silicon mosfets. Pdf performance study of 12cntfet and gdi cntfet based. I had done the simulation using your tool cntfet lab available at nanohub.
The cntfet is a field effect transistor in which carbon nano tubecnt is used in the. Cntfet and types of cntfet are discussed in section 2. Design of low threshold full adder cell using cntfet. In the mode space treatment, the selfenergy of a mode is 19. Performance evaluation of cntfet based ternary basic. Comparison of cntfet based 6t sram and mosfet based. To appear in carbon nanotube electronics, edited by a. Simulation and analysis of cntfets based logic gates in hspice 1neetu sardana, 2l. Hspice simulations have been performed on the logic gates designed using the modeled cntfet. In this work, the impact of chirality and gate oxide thikness on the electrical characteristics of a cntfet are studied. Depicts the voltage vs drain current plot of cntfet with channel length5 nm and chiral vectorm0,n fig.
The subject of this paper is the convetional cntfet. The power dissipation across ternary half adder is 0. Simulation results show that a reduction in power with low delay can be achieved with cntfet design. Introduction since the first reports of singlewalled carbon nanotubes cnts in 1993,1,2 they have been the subject of intense interest for basic and applied research. Planar cntfet geometry we now provide a brief description of typical cntfet geometries, which are grouped in two major categories, planar and coaxial. I have done the simulations for different diameter of the cnt by changing the chirality used in the channel. In this paper we implement a simple dc model for cntfets already proposed by us in order to carry out static analysis of basic digital circuits. Dft based estimation of cnt parameters and simulationstudy of. The og cntfet based circuits possess higher learning efficiency when implemented in neural networks. Virendra swarup group of institutions, unnao, india throughput vlsi systems. The simulation results are presented and the analyses are compared with circuits designed using 32nm mosfet. The cntfet is a field effect transistor in which carbon nano tubecnt is used in the channel region. Simulation of semiconductor processes and devices, pp.
In , a model based on local channel approximation is developed. Cntfet hspice model to represent the effect of uneven spacing. Carbon nanotube field effect transistor cntfet has a wide scope in the field of nanotechnology. In other words, current is actually flowing from drain to source terminal. Pdf design and analysis of cntfet based d flipflop. Performance enhancement of finfet and cntfet at different. Comparison of cntfet based 6t sram and mosfet based 6t sram. Carbon is a group 14 element that resides above silicon on the periodic. Design of universal logic gates based on cntfet for binary.
Gate terminal controls current intensity in the transistor channel and the transistor is in off state if no gate. Section 5 typical analogue circuits and logic blocks have been simulated both. Implementation of mod16 counter using veriloga model of cntfet. Cntfet modeling and performance analysis of device. Performance evaluation of cntfet based ternary basic gates. The contact broadening function can be computed as. Inrtoduction silicon based mos technology is the basic cell of todays. The chiralities used are 5, 0, 10, 0, 19, 0, 26, 0, and the gate oxide thikness varied from 1 to 5 nm.
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