一个圆柱形双栅场效应晶体管的物理模型  

A physical model of cylindrical surrounding double-gate metal-oxide-semiconductor field-effect transistor

作　　者：刘佳文 姚若河[1] 刘玉荣[1] 耿魁伟[1] Liu Jia-Wen;Yao Ruo-He;Liu Yu-Rong;Geng Kui-Wei(School of Electronic and Information Engineering,South China University of Technology,Guangzhou 510641,China)

机构地区：[1]华南理工大学电子与信息学院,广州510641

出　　处：《物理学报》2021年第15期249-256,共8页Acta Physica Sinica

基　　金：广东省重点领域研发计划(批准号:2019B010143003);国家自然科学基金(批准号:61871195)资助的课题.

摘　　要：圆柱形双栅场效应晶体管(CSDG MOSFET)是在围栅MOSFET器件增加内部控制栅而形成,与双栅、三栅及围栅MOSFET器件相比,圆柱形双栅MOSFET提供了更好的栅控性能和输出特性.本文通过求解圆柱坐标系下的二维泊松方程,得到了圆柱形双栅MOSFET的电势模型;进一步对反型电荷沿沟道积分,建立其漏源电流模型.分析讨论了圆柱形双栅MOSFET器件的电学特性,结果表明:圆柱形双栅MOSFET外栅沿沟道的最小表面势和器件的阈值电压随栅介质层介电常数的增大而减小,其漏源电流和跨导随栅介质层介电常数的增大而增大;随着器件参数的等比例缩小,沟道反型电荷密度减小,其漏源电流和跨导也减小.The cylindrical surrounding double-gate metal-oxide-semiconductor field-effect transistor(CSDG MOSFET)is formed by adding an internal control gate to the cylindrical surrounding-gate(CSG)MOSFET.The inner gate of CSDG MOSFET acts as a second gate for enhanced charge control.At present,the research of CSDG MOSFET structure is widely concerned.Compared with double-gate MOSFET,triple-gate MOSFET and CSG MOSFET,the CSDG MOSFET provides good controllability of the gate over the channel.Additionally,the device allows for higher volume inversion than CSG MOSFET,which leads to better output characteristics.In order to study the electrical characteristics of CSDG MOSFET,the potential model of CSDG MOSFET is obtained by solving the two-dimensional Poisson equation in cylindrical coordinates.The effects of gate dielectric,channel length and gate dielectric thickness on the surface potential and electric field of CSDG MOSFET are studied.Besides,the drain-source current model of CSDG MOSFET is established by integrating the inverse charge along the channel.The effects of gate dielectric and gate dielectric thickness on the transconductance of CSDG MOSFET are studied.In addition,the effects of the downscaling of device parameters on the transfer characteristics and transconductance of CSDG MOSFET are studied.The electrical characteristics of CSDG MOSFET are analyzed and discussed.The results show that the minimum surface potential along the channel of CSDG MOSFET decreases with the increase of gate dielectric constant of gate dielectric layer.The electric field along the channel and along the radius,drain-source current and transconductance of CSDG MOSFET increase as the gate dielectric constant increases.The threshold voltage of CSDG MOSFET decreases as the gate dielectric constant increases.Moreover,with the downscaling of device parameters,the transfer characteristics and transconductance of CSDG MOSFET decrease.The performance of CSDG MOSFET can be significantly improved by using high-k gate dielectrics.

关 键 词：圆柱形双栅场效应晶体管 模型 栅介质 电学特性 

分 类 号：TN386[电子电信—物理电子学]