部分耗尽异质环栅场效应晶体管阈值电压模型  

Threshold Voltage Modeling of Partially-Depleted Dual-Material Surrounding Gate Field-Effect Transistor

作　　者：李尊朝[1] 罗诚[1] 王闯[1] 苗治聪 张莉丽[1] 

机构地区：[1]西安交通大学电子与信息工程学院,西安710049

出　　处：《西安交通大学学报》2013年第12期50-54,109,共6页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(61176038)

摘　　要：为抑制短沟道效应和解决载流子传输效率低的问题,提出了部分耗尽异质环栅金属氧化物半导体场效应晶体管(MOSFET)结构(DMSG),并建立了器件的表面电势和阈值电压解析模型。异质环栅由两种具有不同功函数的材料无缝拼接形成,能在沟道中产生电场峰值,降低漏端电场,并屏蔽漏压对最小表面势的影响。通过为沟道耗尽层各区建立柱坐标下电势泊松方程和相应的边界条件方程,采用径向抛物线近似对偏微分方程进行降维和解析求解技术,获得了DMSG结构的解析模型。仿真结果表明,与传统的部分耗尽环栅器件相比,DMSG结构载流子传输效率高,短沟道效应、漏致势垒降低效应和热载流子效应抑制能力强;所建解析模型与数值仿真软件的相对误差小于5%。A partially-depleted dual-material surrounding-gate metal-oxide-semiconductor field- effect-transistor （MOSFET） structure （DMSG） is proposed to suppress the short channel effect and to increase the current drivability. Two-dimensional analytical models for both surface potential and threshold voltage are respectively presented for the novel structure. The dual- material surrounding gate consists of two metals connecting tightly with different work functions, and it can produce the electric field peak near the source in the channel, decrease the electric field near the drain, and mask the influence of the drain voltage on the minimum surface potential. The potential Poisson equations in the two depleted divisions are given with the boundary conditions in the cylindrical coordinate system. The analytical models are derived based on the solution of the partial differential equations through reducing the dimensions with parabolic potential approximation in the direction vertical to the channel. Numerical simulation and comparisons with the traditional partially depleted device show that the DMSG device increases the carrier transport efficiency, and suppresses the short channel effect, drain-induced barrier lowering effect and hot carrier effect, and that the relative error between the derived analytical model and the numerical simulation software is less than 5 %.

关 键 词：部分耗尽 异质环栅 金属氧化物半导体场效应晶体管 阈值电压 

分 类 号：TN386[电子电信—物理电子学]