Design And Optimization Of A Novel Three-input Device

With the popularization of intelligent device such as smart phones and smart homes,there is an increasing demand for high-performance and low-power chips in various industries.At present,the devices mainly used in traditional circuit design are CMOS/Fin FET.CMOS/Fin FET devices are all single input devices,that is,only one gate can input control signals.When CMOS/Fin FET devices are used to design complex circuits,more transistors are needed,which makes it difficult to reduce the power consumption of the circuits.In order to reduce the power consumption of the circuit,scholars have proposed many effective methods.In these methods,multi input devices have attracted the attention of many researchers because they can simplify the traditional CMOS/Fin FET circuit,use fewer devices and significantly reduce the power consumption of the circuit.Taking an independent-gate Fin FET device as an example,a high-threshold independent gate Fin FET device is equivalent to two Fin FETs“in series”.A low threshold independent gate Fin FET device is equivalent to two Fin FETs“in parallel”.A two-input independent-gate Fin FET device is more flexible and efficient than a single-input Fin FET device,which can effectively simplify the circuit structure and reduce the number of devices used.Let's make a bold assumption.Will three input devices be more flexible and efficient when we design a circuit?Can we further simplify the circuit and reduce the number of devices?In this paper,a novel T-channel field effect transistor with three input terminals(Ti-Tc FET)is proposed.The channel structure of the device is T-shaped,which consists of two parts:horizontal channel and vertical channel.The top gate of the device covers the upper part of the horizontal channel,the front gate and back gate cover both sides of the vertical channel respectively.The T-channel structure increases the coupling area between top gate,front gate and back gate,enhances the control ability of top gate to the channel,and makes top gate have the same channel control ability as front gate and back gate.The"T"channel structure can not only make the three gates have the same control ability to the channel,but also bring a unique function to the device:when any two or three of the three inputs of an n-type device are high level,the device turns on,otherwise the device turns off.That is to say,a single transistor is used to realize the logic function of three input"Majority-Not",and only one n-type and one P-type transistor is needed to design the"Majority-Not"gate.In order to study the Ti-Tc FET devices comprehensively,this paper mainly does the following five aspects:1.The three-input device idea that can be used to simplify the circuit is proposed.In the process of studying the independent gate Fin FET circuit,we found that the independent gate Fin FET device with two gates can simplify the traditional circuit structure,verified that the multiple-input device can be used to simplify the traditional CMOS/Fin FET circuit,and put forward an assumption.Can we design a three-input device that can effectively simplify the traditional CMOS/Fin FET circuit?2.The structure of Ti-Tc FET was designed.A novel three-input device that could realize the"Majority-Not"function was created,and named as the T-channel field effect transistor with three input terminals(Ti-Tc FET).3.Optimized the structure of Ti-Tc FET.The effects of gate oxide thickness T_OX,channel thickness T_Si and gate work function?_m on the device performance were studied.The simulation results were verified by Silvaco TCAD tool,and the optimized values of gate oxide thickness T_OX,channel thickness T_Si and gate work function?_m were obtained.4.The Ti-Tc FET device was modeled.The threshold voltage model,subthreshold leakage current model and turn-on current model of Ti-Tc FET devices were constructed,and the simulation verification was carried out by TCAD.5.Ti-Tc FET devices were used to build basic unit circuits.Firstly,the design method of three-input Majority-Not logic based on Ti-Tc FET is introduced.Then,Ti-Tc FET devices will be used to build circuits based on the"Majority-Not"logic.The experimental results show that the number of NAND/NOR,Majority-Not gate and full adder circuit constructed by Ti-Tc FET is 50%,80%and 64%less than that of traditional Fin FET circuits.In conclusion,after studying the advantages and disadvantages of multi-input device structure,a novel"T"structure of three-input device is designed.Through experiments,it is found that the three-input device can simplify the traditional circuit structure effectively and provide a new idea for the future low power circuit design.