Resonant Tunnel Field Effect Transistors Based on Vertical 2D Crystal Heterostructures

基于垂直二维晶体异质结构的谐振隧道场效应晶体管

• 批准号: 1611279
• 负责人: Wenjuan Zhu
• 金额: $ 37万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-10-01 至 2019-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1611279&HistoricalAwards=false
• 关键词: Resonant; Tunnel; Field; Effect; Transistors

The proposed interdisciplinary research combines advances in two dimensional (2D) materials, brain-inspired network computing, and resonant tunnel diodes (RTDs), to create a new device concept: 2D resonant tunnel field-effect-transistor (RTFET). RTFETs based on 2D crystals will solve the lattice matching/dislocation issues of III-V semiconductor based RTDs. The strong negative differential resistance and high frequency response in these devices will be used to perform "comparison" functions, similar to synapses in neurons, for image recognition applications. RTFET-based synapses can potentially reduce energy consumption by more than ten times compared to the circuits based on traditional complementary metal-oxide-semiconductor (CMOS). The ultra-high operating frequencies of RTFETs will enable their applications in high speed wireless communication, THz imaging, and spectroscopy. In addition, RTFETs can also serve as sensitive vehicles to probe 2D/2D interfaces, providing scientific insights on the out-of-plane transport in 2D heterostructures. This research project will not only advance the knowledge of quantum tunneling in 2D crystals, resonant tunneling devices, and brain-like circuits, but also have direct technology impact on image recognition, non-traditional computing, and high frequency wireless communications. The integration of the proposed research with after-school programs in elementary schools, new courses for undergraduate/graduate students, and recruiting/retaining women students, will foster students' interest in nanotechnology while broadening their knowledge base, thus having a positive enduring impact on the education of a world-class and diverse science and technology workforce.The objective of this project is to understand the interlayer resonant tunneling in 2D vertical heterostructures and demonstrate high speed RTFETs with pronounced negative differential resistance at room temperatures for neurosynaptic image recognition applications. The PI will pursue the following four thrusts: (1) fabrication of a variety of 2D vertical heterostructures, including black phosphorus/boron nitride/black phosphorus, tungsten diselenide/molybdenum disulfide/tungsten diselenide heterostructures, with precise control of rotation angles and layer numbers; (2) evaluate the impact of rotation angle, band offsets, tunneling barrier thickness, and interface qualities, on the resonant tunneling currents in the vertical 2D heterostructures; (3) demonstrate high speed RTFETs with pronounced negative differential resistance at room temperatures; (4) demonstrate synapses based on 2D RTFETs, as basic elements in neurosynaptic chips for image recognition applications. The successful execution of this project will expand the knowledge of resonant quantum tunneling in 2D heterostructures, resonant tunneling devices, and neural-network computing. More specifically, this research will elucidate the effect of rotation angle alignment, band extrema location, bandgap, and band offsets on the interlayer resonant tunneling in RTFETs. This will also provide insight into inelastic tunneling and scattering due to interface traps and defects in RTFETs. The fundamental understanding of the resonant tunneling in 2D heterostructures gained in this research project will enable a new class of novel nanoscale electronic devices based on out-of-plane transport instead of the traditional in-plane transport of 2D crystals. This research will also pave the way for new functional devices beyond CMOS and provide an experimental demonstration of neural-network circuits based on RTFETs. The negative differential resistance and fast response in RTFETs can potentially enable a new computing paradigm beyond the traditional von Neumann architecture.

拟议的跨学科研究结合了二维（2D）材料，脑启发网络计算和谐振隧道二极管（RTD）的进步，创造了一个新的器件概念：2D谐振隧道场效应晶体管（RTFET）。 基于2D晶体的RTFET将解决基于III-V族半导体的RTD的晶格匹配/位错问题。这些器件中的强负微分电阻和高频响应将用于执行“比较”功能，类似于神经元中的突触，用于图像识别应用。与基于传统互补金属氧化物半导体（CMOS）的电路相比，基于RTFET的突触可以潜在地减少十倍以上的能耗。RTFET的超高工作频率将使其在高速无线通信、THz成像和光谱学中的应用成为可能。此外，RTFET还可以作为探测2D/2D界面的敏感工具，为2D异质结构中的面外输运提供科学见解。该研究项目不仅将推进2D晶体、共振隧穿器件和类脑电路中量子隧穿的知识，还将对图像识别、非传统计算和高频无线通信产生直接的技术影响。将拟议的研究与小学的课后课程、本科生/研究生的新课程以及招收/留住女学生相结合，将培养学生对纳米技术的兴趣，同时扩大他们的知识基础，从而对世界的教育产生积极的持久影响-本项目的目标是了解二维垂直异质结构中的层间共振隧穿，并展示高性能的在室温下具有显著负微分电阻的高速RTFET，用于神经突触图像识别应用。PI将致力于以下四个方面：（1）制作各种2D垂直异质结构，包括黑磷/氮化硼/黑磷，二硒化钨/二硫化钼/二硒化钨异质结构，精确控制旋转角度和层数;（2）评估旋转角、能带偏移、隧穿势垒厚度和界面质量的影响，在垂直二维异质结构中的共振隧穿电流;（3）展示了在室温下具有显著负微分电阻的高速RTFET;（4）展示了基于二维RTFET的突触，作为图像识别应用的神经突触芯片中的基本元件。该项目的成功实施将扩展2D异质结构中的共振量子隧穿、共振隧穿器件和神经网络计算的知识。更具体地说，本研究将阐明旋转角对准，带极值位置，带隙，和带偏移的RTFET的层间共振隧穿的效果。这也将提供洞察非弹性隧穿和散射由于界面陷阱和缺陷RTFET。在本研究项目中获得的二维异质结构中的共振隧穿的基本理解将使一类新的新型纳米级电子器件的基础上的面外运输，而不是传统的平面内运输的二维晶体。这项研究还将为CMOS之外的新功能器件铺平道路，并提供基于RTFET的神经网络电路的实验演示。RTFET的负微分电阻和快速响应可能会实现超越传统冯·诺伊曼架构的新计算范式。