"Control of surface and interfaces of nano-structures for single electron devices"

这项研究的目的是在原子尺度上控制纳米结构的表面和界面，并将其应用于制造和集成新型单电子器件的器件加工技术。主要研究结果如下：(L)提出并制备了具有肖特基面内栅极和缠绕栅极的新型GaAs基和InGaAs基单电子晶体管。它们在高温下工作，实现了大于单位的电压增益。此外，还成功地制作了逻辑反相器电路和二元判决图(BDD)电路等小规模集成电路。(2)制作并表征了Variotus类型的硅基量子结构和器件。在室温下观察到了纳米硅点的库仑阶梯和单电子输运。此外，在具有20 nm沟道的垂直型硅晶体管中首次发现了量子化电导。在以跳跃输运为主的窄硅沟道中发现了库仑阻塞现象。提出了一种基于非对称隧穿势垒的单电子器件新结构。(3)从原子尺度上研究了碳化硅和氮化镓的表面性质。阐明了纳米金属颗粒在重构的碳化硅表面的形成过程。实现了在(111)Si衬底上形成GaS量子点的新工艺。(4)对量子点中波包的隧穿时间和传播过程进行了理论研究。

The pupose of this research was to control surfaces and interfaces of nanostructures in an atomic scale and its application to the device processing techniques for fabricating and integrating novel single electron devices. The main results are listed below.(l) Novel GaAs- and InGaAs-based single electron transistors having Schottky in-plane and wrap gates were proposed and fabricated. They operated at high temperatures and achieved the voltage gain greater than unity. Furthermore, small-scale integrated circuits such as logic inverter circuits and binary decision diagram (BDD) circuits were stuccessfully fabricated.(2) Variotus types of Si-based quantum structures and devices were fabricated and characterized. Coulomb staircase and single electron transport through nano-crystal Si dots were observed at room temprature. In addition, quantized conductance was seen for the first time in vertical-type Si transistor with a 20-nm channel. Coulomb blockade phenomena were found in a narrow Si channel where a hopping transport is dominant. A novel structure for single electron devices was proposed on the basis of asymmetric tunneling barriers.(3) Surface properties of SiC and GaSe were investigated in an atomic scale. Formation processes of metal particles with nanometer sizes on the reconstructed SiC surfaces were clarified. Furthermore, a novel process for formtion of GaAs quantum dots on the GaSe-terminated (111) Si surface was realized.(4) Tunneling time and propagation process of wave packet in quantun dots were theoretically investigated.