The Influence Of Interface Layer And Depolarization Field On The Electrical Performance Of Negative Capacitance Field Effect Transistor

Ferroelectric negatively charged transistors replace conventional gate oxide materials with ferroelectrics based on conventional MOS tubes,and its subthreshold slope can be as low as 60 mv/dec,which is the key to break through the bottleneck of transistor operating voltage V_DD and device size in the future.Based on this,the thesis,which combines theoretical modeling with numerical analysis,mainly studies negative capacitance effect of ferroelectric field-effect transistors under the condition of hysteresis loop drift.Based on landau-ginzbug-devonshire phenomenological model,Poisson equation and current continuity equation,the negative capacitance hafnium oxide doped yttrium field effect transistor(FET)is established and effect of the conductivity of the interface layer on its electrical performance is annlyzed.First,it turns out that the interface layer conductivity has a certain effect on the negative capacitance field effect transistor.When the interface layer conductivity?=0.035×10^-11?^-1m^-1,Silicon surface potential amplification is the strongest,the gate capacitance is amplified,and the subthreshold swing is reduced,which successfully reduces the power consumption.The results are of great significance for the design of low power field effect transistors.Secondly,under the condition of conductivity of a certain size interface layer,there is an optimal thickness of the film,which makes the ferroelectric film have the strongest negative capacitance effect and the silicon surface potential amplification is the most obvious.The transfer characteristic curve of a transistor above this thickness becomes worse as it decreases or rises.This has important reference significance for optimizing FET.MFIS structure of the FET is established to analyze the effect of depolarization field on gate voltage and silicon surface potential.The results show that the E_d is strongly related to the V_g.When the surface potential of silicon in a very small region is about-0.5 V to 0.4 V,the value of the depolarization field is very small and the size of the surface potential is strongly dependent on the depolarization field.This results have detective significance to the design of new ferroelectric field effect transistors with low power consumption.