GOALI: Multiprobe Investigations of Electron Transport in 2D Electronic Devices

这一学术联络机会（GOALI）项目将哥伦比亚大学的学术领导与IBM t.j.沃森研究中心的技术能力结合在一起。二维（2D）半导体是只有一个原子层厚度的材料。这些材料在整个逻辑、存储器和传感器应用领域的潜在应用引起了电子界的极大兴趣。在过去的几年里，新技术已经出现，这些材料可以生长到几英寸，使它们很容易在标准半导体工艺中使用。然而，这些生长材料的质量目前远不如电子工业使用的经典半导体，如硅。在这个项目中，研究小组将使用四探针扫描隧道显微镜在原子尺度上表征二维薄膜的电子质量。该团队将通过在纳米尺度上直接流过材料的电子电流来确定这些材料中电子流动的主要障碍，同时对高电阻区域进行成像。在项目期间，将开发专门的实验室模块，用于教授本科水平的高级电子概念，并对本科生和研究生进行与电子工业直接相关的实验室技术培训。该提案在哥伦比亚大学的教师和学生与IBM合作伙伴之间进行了重要的互动，学术合作伙伴将在工业环境中获得重要的经验。最后，工业合作伙伴IBM将受益于学术研究的基本性质，结合他们的观点和综合技能。该项目涉及跨学科的大学-工业团队，他们将对过渡金属二硫族化物（tmd__基材料）进行合作研究，其中工业研究参与者（IBM）提供对项目成功至关重要的关键研究专业知识。二维材料的大面积增长使得它们在各种光电器件的工业应用中具有吸引力，但关键问题是理解和控制晶圆尺度材料的传输和接触特性。在这个项目中，扫描隧道电位法将用于直接测量二维材料的纳米级电子输运特性，包括半导体TMD和石墨烯。首先，扫描隧道电位法（STP）将用于测量晶圆级TMD材料上的输运。这些测量将量化与这些材料中的点和线缺陷相关的散射过程。其次，STP将用于测量TMD场效应晶体管的微观带图。这些测量将阐明二维半导体电接触的物理性质。第三，STP将用于测量石墨烯中的电流模式。这些测量将研究石墨烯中粘性流体动力流动的可能性，并定量测量这种状态下的电子粘度。最后，将碳化硅衬底上的石墨烯薄膜用于生长单晶金属薄膜。用STP和传统的运输方法来考察这些薄膜的质量。然后将研究这些薄膜在表面极化激元等离子体中的应用。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This Grant Opportunity for Academic Liaison with Industry (GOALI) project brings together academic leadership of Columbia University with the technical capabilities of the IBM T. J. Watson Research Center. Two-dimensional (2D) semiconductors are materials just a single atomic layer thick. These materials are of great interest to the electronics community for potential applications in a whole range of logic, memory and sensor applications. In the past few years, new techniques have emerged by which these materials can be grown over several inches, making them easily usable in standard semiconductor processes. However, the quality of these grown materials is at present far inferior to the classic semiconductors used by the electronics industry such as silicon. In this project, the research team will use a four-probe scanning tunneling microscope to characterize the electronic quality of 2D films at the atomic scale. The team will identify the major barriers to electron flow in these materials by directly flowing electron currents through the materials at the nanoscale while simultaneously imaging the regions of high resistance. During the project, specialized laboratory modules for teaching advanced electronics concepts at the undergraduate level will be developed, and undergraduate and graduate students will be trained in the laboratory techniques of direct relevance to the electronics industry. The proposal has significant interactions between the faculty and students from Columbia University and the IBM partner where the academic partners will gain significant experience in an industrial setting. Finally, the industrial partner, IBM, will benefit from the fundamental nature of the academic research joining their perspective and integrative skills. This project involves interdisciplinary university-industry teams that will conduct the collaborative research in transition-metal dichalcogenides(TMD_-based materials, in which the industry research participant (IBM) provides critical research expertise that is crucial for the success of the project. The large-area growth of 2D materials have made them attractive for industrial applications in a variety of optoelectronic devices, but a key issue is understanding and controlling the transport and contact properties of wafer-scale materials. In this project, scanning tunneling potentiometry will be used to directly measure the nanoscale electronic transport properties of 2D materials including semiconducting TMD and graphene. First, scanning tunneling potentiometry (STP) will be used to measure transport on wafer-scale TMD materials. These measurements will quantify the scattering processes associated with point and line defects in these materials. Second, STP will be used to measure the microscopic band diagram in TMD field effect transistors. These measurements will elucidate the physics of electrical contact to 2D semiconductors. Third, STP will be used to measure current flow patterns in graphene. These measurements will investigate the possibility of viscous hydrodynamic flow in graphene and measure quantitatively the electron viscosity in this regime. Finally, graphene films on silicon carbide substrates will be used to grow single crystal metal films. The quality of these films will be investigated by STP and traditional transport. The use of these films in surface polariton plasmon applications will then be investigated.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.