Logic Circuit Design Based On FinFET Device

The leakage current of the transistor increases sharply due to the scale of CMOS device being reduced below 20 nm,which results in a large leakage power,increasing the proportion of the total power consumption.Moreover,due to a more obvious short channel effect,device threshold voltage and subthreshold swing are influencd,which greatly limits the performance of circuits.It is urgent to find a new type of device to replace the traditional CMOS transistor.Fin Field-Effect Transistor(FinFET)is a three-dimensional device with no doping or low doping channel surrounded by the gate.Because of the special three-dimensional structure,which has the strong ability of controlling the channel,which can suppresse the short channel effect and the leakage current of the device effectively.Based on these characteristics of FinFET devices above,this paper takes FinFET devices as the object of research and study a dual threshold independent gate FinFET device.A series of digital circuits are designed based on dual threshold independent gate FinFET device.The paper is consist the following parts:1.The effects of FinFET device parameters on device performance are investigated.The relationship between the performance parameters(such as Threshold voltage,subthreshold swing,on-current,and leakage current,and process parameters,such as gate work function,bulk silicon thickness and gate oxide thickness)are investigated.Through the relationship,the device parameters of the Dual-Threshold FinFETs can be obtained.2.The effects of process parameters variations(such as gate work function,bulk silicon thickness,gate oxide thickness and channel length)on the performance parameters(such as threshold voltage,on-state current,and leakage current)can be obtained through analyzing device fluctuation process parameters.At last,through Monte Carlo simulation to analyze the anti-bias performance of the device.3.The current characteristic curve can be obtained through simulating FinFET device with Hspice software.And then simulation verification of FinFET device by TCAD tool.From the relationship between the current curves,the threshold voltage is determined in the current voltage changes the fastest place.The threshold voltage of the FinFET device is divided into a high threshold and a low threshold,where a high threshold transistor can be used as two transistors in series,a low threshold transistor can be used as two transistors in parallel.According to theoperation and shutdown of the high and low threshold FinFET transistors,the on current and leakage current of the high and low threshold FinFET transistors can be measured.4.The structures of circuits used with FinFET devices are researched.The Static complementary logic gates,differential cascaded voltage switch logic gate,4-to-2 compressor,one full adder,the flip-flop,the decimal counter and the memory cell are designed based on independent gate FinFET Devices.Circuit performance is compared in the independent gate(IG)and Short-gate(SG)two modes.In this paper,the relationship between device parameters and performance is observed with Hspice software by adjusting,device parameters in BSIMIMG process library and using Monte Carlo method.After the optimization of the optimal parameters,several circuits are designed based on independent gate FinFET devices,which further study the performance of independent gate FinFET circuit.Compared with short gate FinFET circuit,the simulation results show that the energy consumption delay of dual threshold independent gate FinFET circuit based on the BSIMIMG technology library can be reduced by at least 10%,which improve the overall performance of the circuit.In addition,the independent gate FinFET circuit can effectively reduce the number of transistors and layout area.Device model and circuit research results provide the theoretical basis for industrial production.