Simulation Research On The Performance Of The Three-dimensional SiGe Core-shell Multi-gate Transistor

With the classical planar Metal-Oxide-Semiconductor Field-Effect transistor(MOSFET)scaled down to below 20nm,gate oxide thickness is reduced and gate ability to control the channel region is weakened.Short channel effects,increased leakage current caused by quantum tunneling,high concentration doping induced carrier mobility degradation become more and more serious.Non-classical multiple-gate structures increase the contact area with the channel region,greatly improve the gate control ability,alleviate the short channel effect,improve the subthreshold characteristic and drain induced barrier lowering(DIBL)effect.In this context,this article is based on GTS TCAD simulation tool,Simulated the gate length and the mole fraction of the inner and outer channel in the SiGe Core-shell FinFET device.The following research results have been achieved:1.The structure classification,performance optimization,typical physical effects and GTS TCAD device simulation process of FinFET devices are briefly explained.2.The simulation model of SiGe Core-shell FinFET device is constructed,the influence of gate length on the subthreshold characteristic and the influence of Ge mole fraction of the inner and outer channel region on the device transfer characteristic curve are studied;through comparative analysis,the best inner channel region Ge mole fraction is obtained.3.Through the study of the carrier concentration distribution,select the suitable quantum mode,extracting the hole concentration and energy band structure in the direction perpendicular to the channel,and obtaining the influence of Ge mole fraction of the inner and outer channel region on the current transmission path.Combined with the results of the saturation current and electrical characteristics of the inner and outer channel region mole fraction,we obtain the best outer channel region Ge mole fraction.4.Based on the analysis of the inner and outer channel region Ge mole fraction,the optimal channel region Ge mole fraction is selected and compared with the transfer characteristic curves and electrical characteristics of Si-FinFET and Ge-FinFET.The simulation results show that compared with Si-FinFET devices,~Idsat is about twice as high,and the sub-threshold swing(SS)is about 30m V/dec lower.The shorter the effective gate length,the more obvious the optimization of saturation current and subthreshold swing(SS).