高k+SiO_2栅FD-SOI MOSFET阈值电压和DIBL效应的分析及建模  

Threshold voltage and DIBL effect analysis and modeling for FDSOI MOSFET with high k + SiO_2 gate

作　　者：万璐绪 杨建国 柯导明[1] 吴笛[1] 杨菲 陈甜 Luxu WAN;Jianguo YANG;Daoming KE;Di WU;Fei YANG;Tian CHEN(School of Electronics and Information Engineering,Anhui University,Hefei 230601. China)

机构地区：[1]安徽大学电子工程与信息学院,合肥230601

出　　处：《中国科学：信息科学》2019年第3期342-360,共19页Scientia Sinica(Informationis)

基　　金：国家自然科学基金(批准号:61376098;61076086)资助项目

摘　　要：文章提出了高k+SiO_2栅FD-SOI (fully depleted silicon-on-insulator) MOSFET,开发了它的二维亚阈值区前栅表面电势、阈值电压和DIBL (drain induced barrier lowing)效应计算模型.本文根据器件的结构和不同的介电常数,将亚阈值区的FD-SOI MOSFET分成若干个不同的矩形等效源,构建了这个多角形区域的Poisson方程和Laplace方程的二维边界值问题,然后用分离变量法和特征函数展开法求出了模型的二维解.计算结果表明,高k+SiO_2栅能有效地抑制高k介电常数产生的FD-SOI MOSFET阈值电压退化, DIBL效应加重,以及FIBL效应.由于这个模型列出的是线性代数方程组,它的计算开销小,因此这个半解析模型既可以用于FD-SOI MOSFET的模拟和仿真,又可用做电路模拟器的器件模型.This study aims to propose a gate structure of high k+SiO2 for a fully depleted silicon-on-Insulator(FD-SOI)MOSFET.We developed a two-dimensional model to calculate its subthreshold surface potential of the front gate,threshold voltage,and drain induced barrier lowering(DIBL)effect.Based on the structure and different dielectric permittivity of FD-SOI MOSFET,the MOSFET of the subthreshold state is divided into several distinct rectangular equivalent sources.Furthermore,two-dimensional(2 D)boundary value problems of Poisson and Laplace equations are built on the polygon region.Then,we use the method of separation of variables and the eigenfunction expansion to solve the 2 D boundary value problems,and obtained their 2 D solutions.Computational results show that the high k+SiO2 gate can effectively suppress the degradation of FD-SOI MOSFET threshold voltage,the aggravation of DIBL effect,and the FIBL effect,which are caused by the dielectric permittivity of high k.Since the equations of the model are linear equations,their computational cost is minimal so that the model can be used for not only modeling and simulation of FD-SOI MOSFETs but also as a device model of circuit simulators.

关 键 词：高k+SiO2栅 FD-SOI MOSFET 阈值电压 DIBL效应 二维模型 

分 类 号：TN386[电子电信—物理电子学]