Single-electron-level ballistic transport devices

单电子级弹道输运装置

• 批准号: 0925532
• 负责人: Hong Koo Kim
• 金额: $ 30.51万
• 依托单位: University of Pittsburgh
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2013-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0925532&HistoricalAwards=false
• 关键词: Single; electron; level; ballistic; transport

This project deals with developing a new class of electronic devices that offer femtosecond transit time operating at a single-electron level in room-temperature air ambient. The operating principle of the proposed device structure involves ballistic transport of electrons in a nanoscale void channel that will be formed in the oxide layer of a metal-oxide-semiconductor structure. A metal-oxide-semiconductor structure will be driven into a breakdown regime of operation (that is, the electric field is set greater than the oxide breakdown field strength) in order to form nanoscale leakage channels in the oxide layer. The oxide thickness (channel length) will be designed to be smaller than the mean free collision path in air so that the thus-formed void channels essentially serve as a medium for nanoscale vacuum electronics. In this quasi-vacuum-mode operation in air, the ballistic transport of electrons is expected to demonstrate a space-charge-limited current over a broad range of voltage, following the Child-Langmuir's [voltage]3/2 power law. The electron transit time is calculated to be 10-100 femtosecond, potentially offering over 10-100 terahertz operation. The space-charge-limited transport in the nano-channel is expected to be of single electron level. The single-electron transport with femtosecond transit time can result in the channel current of ~microampere level, potentially offering high signal-to-noise ratio operation of optoelectronic devices at room temperature. This study aims at developing a fundamental understanding of the charge transport process occurring in the localized nanochannels and its application to ultrafast (down to femtosecond level) photodetection.Intellectual MeritElectron transport in a nanometer-scale-confined space is a fundamental process, whose understanding is critically important in developing advanced electronic/optoelectronic devices. The proposed nanoelectronic structure (~10-nm-scale void channels formed in the oxide of a silicon metal-oxide-semiconductor structure) offers the advantage of vacuum in transporting electrons, but does not require any vacuum medium in its operation. Understanding the mechanisms of nanochannel formation and their extreme transport properties (~10 femtosecond transit time) is expected to bring a major advancement to the science and technology of nanoscale electronics/optoelectronics. This study addresses the scientific and engineering challenges in advancing the silicon-metal-oxide-semiconductor-based structure into a new device technology that offers a great promise for ultimate operation at single-electron, single-photon level.Broader ImpactsThis study will make major impacts on various fields such as telecommunications, information processing, instrumentation/metrology, and defense. The multidisciplinary nature of this project will provide an educational paradigm for training future scientists and engineers for the emerging fields of nanoelectronics, nanophotonics and nanoscale vacuum electronics. Students from underrepresented groups will be recruited at various levels and scopes such as graduate research (masters and doctoral degrees), undergraduate research experience, and summer enrichment programs for high school students. These students will gain hands-on-experience through a variety of instrumentation available at the Nanoscale Fabrication and Characterization Facility (a user facility at the PI's institution) mentored by graduate student researchers from the PI's lab.

该项目涉及开发一种新型电子设备，该设备在室温空气环境中提供单电子水平的飞秒传输时间。所提出的器件结构的工作原理涉及在金属-氧化物-半导体结构的氧化层中形成的纳米级空洞通道中电子的弹道输运。金属-氧化物-半导体结构将被驱动进入击穿运行状态（即电场设置大于氧化物击穿场强），以便在氧化物层中形成纳米级泄漏通道。氧化物的厚度（通道长度）将被设计成小于空气中的平均自由碰撞路径，这样形成的空洞通道基本上可以作为纳米级真空电子器件的介质。在空气中的准真空模式操作中，电子的弹道输运有望在宽电压范围内证明空间电荷限制电流，遵循Child-Langmuir的[电压]3/2幂定律。电子传输时间计算为10-100飞秒，可能提供超过10-100太赫兹的操作。纳米通道中的空间电荷限制输运有望达到单电子水平。单电子传输的飞秒传输时间可以产生~微安级的通道电流，有可能在室温下为光电器件提供高信噪比的工作。本研究旨在对发生在局域纳米通道中的电荷传输过程及其在超快（低至飞秒级）光探测中的应用有一个基本的了解。纳米尺度受限空间中的电子输运是一个基本过程，对其的理解对于开发先进的电子/光电器件至关重要。所提出的纳米电子结构（在硅金属-氧化物-半导体结构的氧化物中形成~ 10nm尺度的空洞通道）提供了真空传输电子的优势，但在其操作中不需要任何真空介质。了解纳米通道的形成机制及其极端输运特性（~10飞秒传输时间）有望为纳米电子学/光电子学的科学和技术带来重大进展。本研究解决了将硅-金属-氧化物-半导体结构推进到一种新的器件技术中的科学和工程挑战，该技术为单电子，单光子水平的最终操作提供了巨大的希望。更广泛的影响这项研究将对电信、信息处理、仪器/计量和国防等各个领域产生重大影响。该项目的多学科性质将为培养纳米电子学、纳米光子学和纳米真空电子学等新兴领域的未来科学家和工程师提供一个教育范例。在研究生研究（硕士、博士学位）、本科研究经历、高中生暑期研修项目等不同层次和范围内招收弱势群体的学生。这些学生将获得动手经验，通过各种仪器可在纳米级制造和表征设施（在PI的机构的用户设施）由PI的实验室的研究生研究人员指导。