Investigation Of Transport Characteristics Of MoTe₂ Based Field Effect Transistor

Transition metal telluride has many novel physical and chemical properties.As a new member of the two-dimensional material series,it has great potential in the application of nanoelectronic devices.In this paper,the non-equilibrium Green function and the Poisson equation self-consistent solution method combined with density functional theory are used to analyze and study the transport characteristics of field effect tube based on MoTe₂ material.The main research work is as follows:First,the density functional theory is used to study the electronic structure of MoTe₂ and Mo Se₂ materials,including energy band,state density and so on.The results show that the2H-MoTe₂ material is p-type semiconductor with a very narrow band gap of 1.04e V,and the2H-Mo Se₂ material is p-type semiconductor with a band gap of 1.42e V.In contrast,MoTe₂ is more conducive to electron conduction from the valence band to the band Jumping,conduction of electrons,and improvement of electrocatalytic performance.Secondly,the transport characteristics of MoTe₂-MOSFET were studied.The influence of parameters such as gate length,doping concentration and temperature on the transport characteristics of MoTe₂-MOSFET is analyzed.The results show that the longer gate length of the MoTe₂-MOSFET,the greater switching current ratio and the smaller sub-threshold swing.As the doping concentration increases,the switching current ratio first increases and then decreases,when the doping concentration is 0.01 mole fraction,it has the highest switching current ratio.As the temperature decreases,the switching current ratio increases,and the sub-threshold swing decreases.Therefore,the device performance is optimal at low temperatures.Next,the transport characteristics of MoTe₂-TFET were studied.By studying the influence of gate length,doping concentration,temperature,and oxide layer material on the MoTe₂-TFET transport characteristics.The results show that when the gate length is above 8nm,the device has the lower off-state current and the higher switching current ratio.When the MoTe₂-TFET doping concentration is equal to 0.009 mole fraction,it's switching current ratio can reach 10¹⁰-level,and the subthreshold swing is relatively low,so in this case,the electrical performance is optimal.When the temperature is less than or equal to 300K,When the temperature is less than or equal to 300K,it has little effect on the electrical performance of the MoTe₂-TFET,and and all of them have 10¹⁰switching current ratio.But when the device is at high temperature,its electrical performance begins to decline.Then,the electrical characteristics of MoTe₂-TFET are compared with Mo S₂-TFET and Mo Se₂-TFET.The result shows that the transport characteristics of MoTe₂-TFET are better than those of Mo S₂-TFET and Mo Se₂-TFET.Compared the off-state current and switching current ratio of MoTe₂-TFET with the predicted value corresponding to ITRS,the results show that the off-state current and switching current ratio of nano-MoTe₂-TFET are both better than the predicted value of ITRS.Finally,the electrical characteristics of the circuit based on MoTe₂-TFET are studied.Calculate and analyze the switching delay time,power consumption and other parameters of the basic circuit such as the two-input AND gate,three-input OR gate,full adder and inverter.Then,the inverter constructed by MoTe₂-TFET was optimized by adjusting the doping concentration.