Suppression Of Short Channel Effect And Performance Optimization Of Negative Capacitance Transistor

As a novel device in today’s integrated circuits,Negative Capacitance Field Effect Transistors(NCFET)stands out for its outstanding ultra-low power consumption and compatibility with CMOS process.However,as the main factor limiting the geometric scaling of transistors,the short channel effect(SCE)also exists in NCFET and affects the device performance deeply.Therefore,for advanced NCFET with different device structures,this thesis explores the suppression scheme of short channel effect,and its performance optimization of devices and circuits.At the same time,simulation analysis and verification are carried out by Sentaurus TCAD.First of all,aiming at the short channel effect of NCFET with fully depleted silicon-on-insulator technology(NC-FDSOI),local Gaussian heavy doping technology(LoGHeD)in the channel near the drain side is proposed.The results show that the LoGHeD technology can effectively reduce the current loss and suppress the negative differential resistance(NDR)effect of NC-FDSOI.And compared with the traditional NC-FDSOI,the performance of NC-FDSOI with LoGHeD technology can be optimized.Secondly,aiming at the short channel effect of NCFET with three-dimensional FinFET structure(NC-FinFET),a technical scheme of global Gaussian light doping in the drain extension region is proposed.The simulation results show that among the three global light doping methods from top-to-bottom,from bottom-to-top and from middle-to-both sides,the top-to-bottom light doping has the best effect on suppressing the SCE and can effectively reduce threshold voltage and suppress NDR effect.Finally,based on the above LoGHeD technology,a pair of NMOS and PMOS negative capacitance transistors are designed,and their performance optimization effect on negative capacitance CMOS inverter and six-transistor static random access memory(SRAM)are analyzed.The results show that this technology can not only suppress the SCE but also improve the DC gain of inverters and the stability of SRAM.This thesis provides the doping techniques for the suppression of short channel effect in NC-FDSOI and NC-FinFET devices,respectively,and also gives doping schemes for optimizing the performance of negative capacitance CMOS devices and circuits.