Control of single-electron-tunneling characteristics in Si multidot structure for applying to nanodot automaton

为了应用于纳米点自动机和最终低功耗的单电子存储器，我们制备了二维(2D)硅多点沟道场效应晶体管(FET)，并研究了它们的单电子/空穴隧穿(SET/SHT)特性。此外，我们还模拟了二维随机多点FET的交流电流特性，以实现电子的逐个转移。本项目的主要成果如下：(1)制作的二维硅多点沟道场效应管在70K以下表现出库仑阻塞(CB)效应引起的电流振荡，表明SET/SHT已经实现。根据SET/SHT特性，我们得出结论，考虑到一串点，即一系列隧道结，在2D多点沟道中形成了源极和漏极之间的载流子渗流路径，并且最高电阻的隧道结主导了载流子的输运。此外，通过照明和施加侧栅BIA…更多的S，观察到了当前峰的产生和/或移位。这些现象可以用光照度和侧栅偏置为电流渗流路径附近的点提供额外电荷的模型来解释。(2)在漏极电压和栅极电压的特定范围内，观察到二维硅多点沟道FET的SHT特性中的电流波动。这种现象归因于电流渗流路径附近的点与时间相关的充放电和极性转换。(3)利用开尔文探针力显微镜，我们直接观察到了晶体管工作过程中载流子在硅多点沟道中的流动。在室温下，我们首次成功地对部分沟道中的载流子流动进行了成像。(4)利用CB正统理论数值研究了二维随机多点沟道场效应管的交流特性。结果表明，可以实现电子逐个转移的旋转门操作和单电子泵浦操作。这些操作可以用多点FET的稳定性图来解释。较少

For the application to nanodot automaton and ultimately-low-consumption single-electron memory, we fabricated two-dimensional (2D) Si-multidot-channel field-effect transistors (FETs) and investigated their single-electron/hole-tunneling (SET/SHT) characteristics. In addition, we also simulated the alternative current characteristics of 2D random-multidot FETs for the realization of one-by-one transfer of electrons. The main results from this project are listed below.(1)The fabricated 2D Si-multidot-channel FETs show current oscillation due to the Coulomb blockade (CB) phenomenon below 70K, indicating the realization of SET/SHT. From the SET/SHT characteristics, we concluded that a carrier percolation path between source and drain electrodes, considering a string of dots, namely, a series of tunnel junctions, is formed in the 2D multidot channel, and that the highest-resistance tunnel junctions dominate the carrier transport. Moreover, by illuminating light and by applying side-gate bia … More s, the generation and/or shift of the current peaks were observed. These phenomena can be explained by the model in which the light illumination and side-gate bias supply an additional charge to a dot adjacent to the current percolation path.(2)The current fluctuation in SHT characteristics of the 2D Si-multidot-channel FET was observed in the particular ranges of drain voltage and gate voltage. This phenomenon is attributed to the time-dependent charging-discharging and polarity-switching of the dots adjacent to the current percolation path.(3)By Kelvin-probe force microscopy, we observed directly the carrier flowing in the Si multidot channel during the transistor operation. At room temperature, we successfully imaged the carrier flowing in a part of the channel, for the first time.(4)We investigated numerically the alternating-current characteristics in 2D random-multidot-channel FETs using the CB orthodox theory. It was found that the turnstile operation and single-electron pump operation meaning that electrons are transferred one by one can be performed. These operations can be interpreted using the stability diagram of the multidot FET. Less