Understanding the Nature of Interfaces in Two Dimensional Electronic Devices(UNITE)

了解二维电子设备接口的本质（UNITE）

• 批准号: 1407765
• 负责人: Robert Wallace
• 金额: $ 42万
• 依托单位: University of Texas at Dallas
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1407765&HistoricalAwards=false
• 关键词: Understanding; Nature; Interfaces; Two; Dimensional

The ability to reduce the size of the basic switch in computers, the transistor, is being seriously challenged. Materials that have been used for decades, such as silicon, are anticipated to soon reach the limit of their performance. This will impact applications where reduced power is needed, along with high speed switching, such as portable electronics and cell phones, as well as larger power intensive operations, like data storage and server centers. The collaborative international team of researchers in this program will focus on determining the feasibility of using the ultimate limit for such switches: atomically-thin, two-dimensional (2D) layers. The materials to be studied, called "transition metal dichalcogenides," are unique when produced in atomically thin sheets, and exhibit promising properties that may enable efficient low power, high performance computing. A key property that will be studied is the surface and interfaces of these materials as they are combined to form the transistor, and how the chemical and physical properties of these interfaces impact and improve the transistor electrical switching behavior. The research results could enable the possibility of reducing the power consumption associated with the broad spectrum of electronic devices, which drive the information and communication age. This will be good for society in terms of extended battery life in portable devices and also good for the environment in terms of reducing the total electrical energy consumed by information and communication technologies. The project, entitled "Understanding the Nature of Interfaces in Two-Dimensional Electronic Devices (UNITE)," brings together leading researchers from the USA, the Republic of Ireland and Northern Ireland, each funded by their respective government agencies through the US Ireland R&D Partnership Program. The project will provide training to five graduate students in the USA and Ireland, and will include student exchanges between the Institutes providing a broader scientific and cultural experience for the graduate students supported through the project.The UNITE project will investigate the synthesis, device fabrication and characterization of 2D transition metal dichalcogenides semiconductors for applications in low voltage tunnel field effect transistors. We will explore two separate routes to large area synthesis through van der Waals epitaxy and atomic layer deposition. In parallel, characterization and understanding of the surfaces and interfacial regions between commercially available bulk crystals and technologically relevant contacts and insulators will be conducted. This will be accomplished using a combination of in-situ and ex-situ characterization covering questions such as: how can 2D semiconductor surfaces be functionalized to allow uniform and continuous oxide thin films to be formed by atomic layer deposition; can capacitance-voltage based metrology be applied to metal-oxide-semiconductor systems on 2D semiconductor surfaces; what is the nature of conduction for metal contacts on 2D semiconductors; and how are the atomic scale electrical properties related to larger area contacts' It is noted that the development of growth methods for large area substrates will not only demonstrate the potential to move 2D semiconductor based transistors from research to production, but will also provide a source of technologically interesting 2D semiconductor materials for basic study which are not commonly available through geological sources. Finally, the growth and characterization studies will be applied to the fabrication of a tunnel field effect transistor based on two dimensional semiconductor heterostructures. If the UNITE team can successfully understand the issues relating to large area 2D synthesis, uniform insulator deposition, ohmic contact formation, and charge transport in single or few layer 2D semiconductors, this knowledge will be relevant to a range of potential device architectures.

缩小计算机基本开关晶体管尺寸的能力正受到严重挑战。硅等已经使用了几十年的材料预计很快就会达到其性能的极限。这将影响需要降低功耗的应用，以及高速开关（例如便携式电子产品和手机），以及更大的功耗密集型操作（例如数据存储和服务器中心）。该项目的国际研究人员协作团队将重点确定使用此类开关的最终极限的可行性：原子薄的二维 (2D) 层。所研究的材料被称为“过渡金属二硫属化物”，在以原子级薄片形式生产时是独一无二的，并且表现出有前途的特性，可以实现高效的低功耗、高性能计算。将研究的一个关键特性是这些材料组合形成晶体管时的表面和界面，以及这些界面的化学和物理特性如何影响和改善晶体管的电开关行为。研究结果可以降低与各种电子设备相关的功耗，从而推动信息和通信时代的发展。这对社会有好处，可以延长便携式设备的电池寿命，也有利于环境，可以减少信息和通信技术消耗的总电能。该项目名为“了解二维电子设备接口的本质（UNITE）”，汇集了来自美国、爱尔兰共和国和北爱尔兰的领先研究人员，每个项目均由各自的政府机构通过美国爱尔兰研发合作伙伴关系资助程序。该项目将为美国和爱尔兰的五名研究生提供培训，并将包括各研究所之间的学生交流，为该项目支持的研究生提供更广泛的科学和文化体验。UNITE 项目将研究合成、设备制造和用于低压隧道场效应晶体管应用的二维过渡金属二硫族化物半导体的表征。我们将通过范德华外延和原子层沉积探索两种不同的大面积合成途径。与此同时，将对市售块状晶体与技术相关的触点和绝缘体之间的表面和界面区域进行表征和理解。这将通过结合原位和异位表征来实现，涵盖的问题包括：如何对二维半导体表面进行功能化，以允许通过原子层沉积形成均匀且连续的氧化物薄膜；基于电容电压的计量可以应用于二维半导体表面上的金属氧化物半导体系统吗？二维半导体上金属接触的导电性质是什么？以及原子尺度的电学性质与大面积接触有何关系。值得注意的是，大面积衬底生长方法的发展不仅将展示将基于二维半导体的晶体管从研究转向生产的潜力，而且还将提供一种来源用于基础研究的技术上有趣的二维半导体材料，这些材料通常无法通过地质来源获得。最后，生长和表征研究将应用于基于二维半导体异质结构的隧道场效应晶体管的制造。如果UNITE团队能够成功理解与大面积二维合成、均匀绝缘体沉积、欧姆接触形成以及单层或少层二维半导体中的电荷传输相关的问题，那么这些知识将与一系列潜在的器件架构相关。