量子点浮置栅量子线沟道三栅结构单电子场效应管存储特性的数值模拟  

Simulation of a triple-gate single electron FET memory with a quantum dot floating gate and a quantum wire channel

作　　者：刘奎[1] 丁宏林[1] 张贤高[1] 余林蔚[1] 黄信凡[1] 陈坤基[1] 

机构地区：[1]南京大学物理系,固体微结构国家实验室,南京210093

出　　处：《物理学报》2008年第11期7052-7056,共5页Acta Physica Sinica

基　　金：国家重大科学研究计划项目(批准号:2006CB932202);国家自然科学基金(批准号:90301009,60571008)资助的课题~~

摘　　要：通过建立二维薛定谔方程和泊松方程数值模型,对基于硅量子点浮置栅和硅量子线沟道三栅结构单电子场效应管(FET)存储特性进行了研究.通过在不同尺寸、栅压和不同写入电荷条件下,对硅量子线沟道中电子浓度的二维有限元自洽数值求解,研究了在纳米尺度下硅量子线沟道中量子限制效应和电荷分布对于器件特性的影响.模拟结果发现,沟道的导通阈值电压随着尺寸的缩小而提高,并随浮置栅内存储的电子数目的增加而明显升高.然而,这样的增加趋势在受到纳米尺度沟道中高电荷密度的影响下将出现非线性饱和趋势.进一步研究发现,当沟道尺寸较小时,沟道内的强量子限制效应能够有效地抑制非线性饱和趋势.另外,由于沟道阈值电压偏移量能灵敏地反映出浮置栅内电子数目的变化,这也为多值存储功能提供了可能.This paper investigates a triple-gate single electron FET memory with a Si quantum dot floating gate and a Si quantum wire channel by establishing a numerical model of two-dimensional Schrdinger and Poisson equations.The electron concentration in the silicon quantum wire channel of different scales is investigated under conditions that diverse gate voltage and programming voltage are applied with a two-dimensional finite element solution.The influence of the quantum confinement effect and the electron distribution in the nano-scale channel on the structure is also investigated.Results of the simulation show that,the threshold voltage increases when the size of the channel decreases,and the voltage also increases as the number of electrons on the floating gate increases.However,a non-linear saturation tendency occurs when the number of injected electrons increases further,due to the high density of carriers in the nanoscale Si nanowire channel.Further research shows that the strong quantum confinement effect in the channel can effectively restrain the saturation tendency when the size of the channel is small enough.It＇s worth mentioning that the threshold voltage shift reflects the number of electrons stored on the floating gate.This effect implies a possibility of multi-level storage.

关 键 词：三栅单电子FET存储器 量子效应 薛定谔方程 泊松方程 

分 类 号：TN386[电子电信—物理电子学] O471.1[理学—半导体物理]