【作者】 许海霞；

【导师】 李志扬；

【作者基本信息】 华中师范大学 ， 凝聚态物理， 2005， 硕士

【摘要】 本论文采用Monte Carlo法对单电子三极管、单电子存储器和单电子加法器等典型单电子器件进行了数值模拟。详细考察了隧道结电阻、电容以及器件结构布局等结构参数和电源电压、温度等工作参数对单电子器件电学性能的影响。 通过对单电子三极管电学特性的数值模拟,发现库仑阻塞效应受温度的影响很大,温度升高,库仑阻塞变窄最后解除;同时,单电子三极管I-V曲线的振幅随着隧道结电容的增大而减小,但I-V曲线的周期保持不变。 对多隧道结单电子动态存储器、对称陷阱型单电子动态存储器和环型单电子动态存储器等三种不同结构的单电子动态存储器进行数值模拟。由数值计算结果,发现在相同条件下,环型单电子动态存储器的存储时间比对称陷阱型单电子动态存储器的存储时间约高二个数量级,而多隧道结单电子动态存储器存储时间比对称陷阱型单电子动态存储器的存储时间约低一个数量级。这说明单电子存储器的内部结构方案对存储时间影响很大。 通过对单电子加法器进行数值模拟,发现温度对其电学特性的影响非常明显,温度越低,库仑台阶效应越显著,温度升高,台阶效应减弱;加法器对栅极电容器的电容非常敏感,栅极电容器的电容值越大,则库仑台阶宽度越窄,相反时,库仑台阶变宽;而改变隧道结的电容、电阻,对加法器的电学特性没有明显的影响。 此外,本论文提出了一种新的单电子器件的宏观模型,利用该模型可以把单个单电子三极管处理为一个常规电子元件,从而对满足一定条件的由许多单电子器件组成的复杂系统,可以采用通用集成电路模拟软件SPICE进行分析模拟,从而可以节省几个数量级的计算时间。更多还原

【Abstract】 The thesis simulated the behavior of single-electron transistor, single-electron dynamic memory and single-electron adder by means of Monte Carlo method.The electric performance of the single-electron devices under the influence of such structural parameters as the tunnel junction capacitance and resistance,and the working parameters such as magnitude of voltage pulse and temperature have bene investigated.For single-electron transistor,it was found that the Coulomb blockade depends much on temperature. When the temperature becomes higher,the Coulomb blockade range becomes narrower or even disappears. If the tunnel junction capacitance becomes larger, the amplitude of the I-V curve of single-electron transistor becomes smaller, but the period is unchanged.For multi-tunnel-junction type,symmetrical trapping type and the ring type single-electron dynamic memory, as the results shows that the storage time of the ring single-electron dynamic memory is two magnitudes larger than that of the symmetrical trapping type single-electron dynamic memory, but the storage time of the multi- tunnel-junction type single-electron dynamic memory is one magnitude lower than that of the symmetrical trapping single-electron dynamic memory,which indicates that the device configuration greatly influence its performance.For single-electron adder, when temperature becomes lower,the Coulomb staircase becomes more obvious. If the gate capacitance becomes larger, the Coulomb staircase becomes narrower. But the tunnel junction capacitance and resistance make little difference to Coulomb staircase.Besides,the thesis offered a new macro-model for single-electron devices. With this macro-model a single electron transistor can be treated as a classical electronic element and complex single electron circuits satisfying certain conditions could beanalyzed and simulated by SPICE, a popular software for simulating of large scale integrated circuits,thus saviny magnitudes of CPU time.更多还原