Model And Simulation Of Negative Capacitance FET

As one of the most potential devices in the field of Low Power Consumption,because of its concise principle,Negative Capacitance Field-Effect Transistor?NCFET?has been widely studied by scholars since it was proposed.Especially after the FE doped-HfO₂ material has been discovered,the NCFET based on ferroelectric HfO₂ has become a research hotspot because of the compatibility with CMOS process.Firstly,the principle of Negative Capacitance?NC?effect of ferroelectric capacitor is discussed.However,as for a standalone ferroelectric capacitor,the NC effect cannot be observed.By employing a non-FE element between the FE and the voltage source in the simulatation circuit,the NC effect can be observed due to that the compensating charge supply from the voltage source to screen the high polarization charges can be manipulated in a controlled manner.This creates a finite D_P across the FE layer which attempts to decrease the voltage across it,leading to NC effect.The simulation circuit structure of negative capacitance effect is established in TCAD sentaurus.The negative capacitance effect of Single-Domain?SD?and Multi-Domain?MD?ferroelectric capacitors is simulated,and the influence of different parameters on the intensity of NC effect of ferroelectric capacitors is studied.Secondly,the device model of MD-FDSOI-NCFET was built.Based on the equivalent capacitance model of the device and the free energy landspace of ferroelectric material,the principle of Low Sub-threshold Swing?SS?was analyzed.The simulation of MD-FDSOI-NCFET was completed by TCAD Sentaurus.The simulation results show that with the increase of t_fe,t_si,?and g,and the decrease of?and V_D,the SS decreases.The SS_min of MD-FDSOI-NCFET with 10 nm ferroelectric HfO₂ is 3.496mV/dec,and compared with the intrinsic FDSOI,the SS_ave was reduced from 68.273mV/dec to41.780mV/dec.In addition,the DIBR effect of NCFET was studied qualitatively,and definted the parameter DIBR which represents the intensity of DIBR effect.The following conclusions can be drawn from the simulation study.With the increase of V_G,g,t_fe and?and the decrease of?,the intensity of DIBR effect increases.Among these parameters,t_fe is the most influential parameter to the DIBR effectFinally,the device models of MD-DG-NCFET and MD-TG-NCFET are established.Based on simulation in the TCAD Sentaurus,the conclusion is as follows,as for MD-DG-NCFET with 10nm ferroelectric HfO₂ when the thickness of gate oxide is 2nm,the gradient coefficient is 2cm³/F,the SS_min is 49.882mv/dec.In the whole current magnitude,the SS_ave is 51.849mv/dec.For MD-TG-NCFET,the SS_min is 50.685mv/dec,and in the whole current magnitude,the SS_ave is 53.904mv/dec.Compared with the MD-FDSOI-NCFET,the difference between the SS_min and the SS_ave of the MD-MG?Multi-Gate?-NCFET is smaller,which is due to the strong grid control ability of the MG structure.The simulation results show that the SS decreases with the increase of t_fe,g,?and the decrease of?.Also,the influence of different parameters on the intensity of DIBR effect of MD-MG-NCFET is studied.The simulation results show that with the increase of g,t_fe,?and the decrease of?,the strength of DIBR effect increases.