Advanced Tunneling-Based Detectors and Imaging Systems for Millimeter-Wave and THz Sensing and Imaging

用于毫米波和太赫兹传感和成像的先进隧道探测器和成像系统

• 批准号: 1508057
• 负责人: Patrick Fay
• 金额: $ 38万
• 依托单位: University of Notre Dame
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1508057&HistoricalAwards=false
• 关键词: Advanced; Tunneling; Based; Detectors; Imaging

This project will investigate and develop devices for millimeter-wave and THz detection and imaging systems with superior performance and advanced functionalities. This technological area has a wide range of applications of societal benefit, including scientific applications such as radiometry and remote sensing (climatology, radio astronomy, chemical spectroscopy), security applications such as through-barrier imaging (i.e. the ability to detect persons or objects through packaging, walls, etc.) and explosive detection, and other sensing applications such as avionic guidance and imaging through fog, sand, and other visible obscurants, medical imaging, and industrial process control (e.g., detection of subsurface defects). The research involves two main thrust areas: (1) device-level demonstration of ultra-sensitive, low-noise heterostructure interband tunneling-based detectors, and (2) system-level demonstration of prototype antenna-coupled detectors and imaging arrays. The devices being explored promise noise levels more than 30 times lower than conventional approaches. This much lower noise allows systems to be greatly simplified, leading to much lower size, weight, and cost, and enabling practical implementation and exploitation of millimeter-wave and THz imaging in cost-sensitive commercial and civilian applications. The project will also produce prototype imaging arrays offering spectroscopic and polarization sensitivity, allowing more than just "grayscale" imaging. This enhanced functionality is valuable for material identification and characterization, as well as to provide the ability to discriminate among similar substances and objects in imaging applications. The project provides significant educational opportunities for students from high school science and technology outreach through graduate-level research opportunities. The project features an interdisciplinary approach, with effort in both device design and optimization as well as imaging array and system design. This approach ensures that the devices developed serve the needs of the system architectures, and the system architectures can be tailored to fully tap the potential of devices. Two emerging device technologies will be explored: heterostructure backward diodes (HBDs) and tunneling field-effect transistors (TFETs); using interband tunneling to generate the detectors? second-order nonlinearity provides significant advantages in terms of sensitivity and noise performance; the sensitivity can exceed the fundamental limits imposed by thermionic emission in Schottky and field-effect transistor (FET) detectors, while operating with zero applied bias for low flicker (1/f) noise and high sensitivity. These devices will be monolithically integrated with planar antennas in novel configurations to enable frequency tuning and polarization-resolved detection in the millimeter-wave and THz regimes. Simulations indicate that noise equivalent power (NEP) of 0.05 pW/Hz1/2 and below should be possible to achieve. Through device design improvements (i.e., modifications to the epitaxial wafer structure, focusing on novel stepped-barrier designs) and scaling (reduction in critical lateral dimensions through advanced fabrication processing), devices with operational frequencies well into the THz will be demonstrated. Imaging arrays with frequency tuning capability (implemented with varactive tuning of planar annular slot antennas) and polarization discrimination (also using loaded annular slot antennas) will be prototyped and assessed to validate the performance of the detectors for imaging applications. The research scope includes exploration of the relevant physics in interband tunnel diodes and tunneling field effect transistors (TFETs), detailed device design and optimization, experimental fabrication and characterization of devices and validation of the device physical models, and prototyping of imaging arrays leveraging these devices. The intellectual impact includes advancing the understanding of device designs for leveraging interband tunneling for millimeter-wave and THz detection, as well as imaging array architectures and approaches to spectroscopic and polarization-resolved imaging in this frequency regime. These devices and imaging arrays can be expected to find applications in a diverse range of detection and imaging applications in the scientific, industrial, and security arenas.

该项目将研究和开发具有卓越性能和先进功能的毫米波和太赫兹探测和成像系统设备。该技术领域具有广泛的社会效益应用，包括辐射测量和遥感（气候学、射电天文学、化学光谱学）等科学应用，穿障成像（即穿过包装、墙壁等探测人员或物体的能力）和爆炸物探测等安全应用，以及通过雾、沙子和其他可见光进行航空电子制导和成像等其他传感应用 遮蔽物、医学成像和工业过程控制（例如，地下缺陷的检测）。该研究涉及两个主要领域：（1）超灵敏、低噪声异质结构带间隧道探测器的设备级演示，以及（2）原型天线耦合探测器和成像阵列的系统级演示。 正在探索的设备承诺噪音水平比传统方法低 30 倍以上。 这种低得多的噪声使得系统能够大大简化，从而大大降低尺寸、重量和成本，并能够在成本敏感的商业和民用应用中实际实现和利用毫米波和太赫兹成像。 该项目还将生产具有光谱和偏振灵敏度的原型成像阵列，不仅可以实现“灰度”成像。 这种增强的功能对于材料识别和表征以及提供在成像应用中区分相似物质和物体的能力非常有价值。 该项目通过研究生水平的研究机会，为高中科学技术推广的学生提供了重要的教育机会。 该项目采用跨学科方法，致力于设备设计和优化以及成像阵列和系统设计。 这种方法确保开发的设备满足系统架构的需求，并且可以定制系统架构以充分挖掘设备的潜力。 将探索两种新兴器件技术：异质结构反向二极管（HBD）和隧道场效应晶体管（TFET）；使用带间隧道来生成探测器？二阶非线性在灵敏度和噪声性能方面提供了显着的优势；灵敏度可以超过肖特基和场效应晶体管 (FET) 探测器中热电子发射所施加的基本限制，同时在零外加偏压下工作，实现低闪烁 (1/f) 噪声和高灵敏度。 这些器件将以新颖的配置与平面天线单片集成，以实现毫米波和太赫兹范围内的频率调谐和偏振分辨检测。 仿真表明，噪声等效功率 (NEP) 应该可以达到 0.05 pW/Hz1/2 及以下。 通过器件设计改进（即修改外延晶圆结构，重点关注新颖的阶梯势垒设计）和缩放（通过先进制造工艺减小关键横向尺寸），将展示工作频率远至太赫兹的器件。 具有频率调谐功能（通过平面环形缝隙天线的变差调谐来实现）和偏振鉴别（也使用负载环形缝隙天线）的成像阵列将被原型化和评估，以验证成像应用探测器的性能。 研究范围包括带间隧道二极管和隧道场效应晶体管（TFET）相关物理的探索、详细的器件设计和优化、器件的实验制造和表征以及器件物理模型的验证，以及利用这些器件的成像阵列的原型设计。 智力影响包括加深对利用带间隧道进行毫米波和太赫兹检测的设备设计的理解，以及成像阵列架构和在此频率范围内进行光谱和偏振分辨成像的方法。这些设备和成像阵列有望在科学、工业和安全领域的各种检测和成像应用中找到应用。