Tunneling Current Of Carbon-based Field- Effect Transistors And Its Influence On The Performance Of Circuits

Firstly, to investigate the current characteristics of nanoscale carbon-based FETs, a quantum kinetic model based on two-dimensional non-equilibrium Green’s function(NEGF) and Poisson equation is developed. Transport properties of carbon-based FETs based on gate and channel engineering is studied. And on the basis of the electrical characteristic, the research is expanded to circuits. The performance parameters of circuits constructed by gate and channel engineering carbon-based FETs have been calculated. Finally, the impact of gate tunneling leakage currents on the logic operation of circuit is discussed. The main contents of this paper can be concluded as follows:Based on the gate and channel engineering, electronic characteristics of carbon-based FET is studied. Using multi-body quantum NEGF method, the electrical characteristics of hetero-material-gate with lightly doped drain and source(LDDS-HMG-CNTFET) is investigated. Results show that, the carbon-based device is similar to the general FET. For example, with reducing gate length, the DIBL effect is increasing. And,by the reduction of oxide layer thickness, the sub-threshold performance is improved. In addition,compared with single-gate carbon-based FET,The hetero-material-gate carbon-based FET with the lightly doped drain and source has better ability of the gate controlling,better ability to suppresses short- channel effects(SCEs), lower leakage current,higher on-off current ratios and so on.On the basis of quantum transport model, the transport characteristics of carbon-based device is discussed. On the basis of international technology roadmap for semiconductors,optimizating the structure of new device.On the basis of device electical characteristics, using the HSPICE with look-up table based Verilog-A models, the performance parameters of some circuits based on carbon-based FET are discussed, such as LDDS-HMG-CNTFET based inverter and LDDS-HMG-CNTFET based SRAM. Result show LHCINV has lower delay,power and power delay product.And LHCSRAMs has higher static noise margin and lower delay,power,power delay product.Schrodinger equation is used to study the gate tunneling current. Due to the impact of the gate tunneling effect, it makes the circuit logic error.