EAGER: Ultra-High-Performance Terahertz Detection Exploiting Super-Steep-Subthreshold-Slope (S4)-FinFETs

在过去的几十年里，太赫兹频率(0.1-30太赫兹)因其在天文、成像、光谱、通信等领域的广泛应用而成为人们关注的对象。尽管最近取得了重大进展，但仍然需要在这些频率下有效地工作的半导体器件。该项目将在短时间内为太赫兹社区的一个长期存在的问题提供答案：如何在室温下实现对铸造厂友好、大规模可制造的固态设备中非常敏感的太赫兹检测。为了实现这一目标，本工作旨在开发基于超陡峭-亚阈值-斜率的场效应管作为有效的太赫兹探测器。该项目将是第一个对这种新兴晶体管技术的太赫兹应用进行研究的项目，预计将在未来几年改变太赫兹技术的格局。事实上，我们的期望是在太赫兹探测方面提供超过两个数量级的性能提升，这是太赫兹社区非常感兴趣的。更广泛地说，将新兴晶体管技术的独特特性用于可行的现实世界应用也是半导体设备社区高度感兴趣的事情。这一研究愿景与指导新一代电子设备、高频电子、模拟电路、太赫兹和光学领域的研究生和本科生的强烈教育目标交织在一起，通过为他们提供前沿研究的实践经验来激发他们的批判性思维和好奇心。考虑到美国未来对训练有素的工程师和科学家的预计需求，这一点具有重要意义。该项目旨在开发基于超陡峭-亚阈值-斜率的场效应晶体管作为高效的太赫兹探测器。在这些器件中实现非常敏感的太赫兹响应的基本机制是其超陡峭的亚阈值斜率(10 mV/dec)，这是弱碰撞电离诱导的正反馈的结果，可以产生非常大的响应率。根据测量的已制造器件的直流特性的初步数据预测，相对于目前所有现有的室温太赫兹探测器技术，在响应率和噪声等效功率方面都有更好的性能，即噪声等效功率~0.01pW/(Hz0.5)。超陡坡场效应晶体管将被制造和配置为超高性能太赫兹探测器。由于其超陡峭的斜率响应，这项技术在不增加成本的情况下，可以承诺比室温FET和肖特基二极管太赫兹探测器的热限制10A/W响应度高两个数量级以上。这种水平的性能是常规的cmos技术所无法达到的。此外，与太赫兹探测器(如隧道FET)等其他前景看好的后CMOS晶体管技术相比，这些器件构成了一个更强大的平台，因为：(A)已经展示了根据太赫兹探测器的要求具有直流性能的超陡坡场效应晶体管的室温演示，(B)超陡坡场效应晶体管是基于硅基的，并且100%与CMOS工艺兼容。

Over the past decades, the terahertz frequency regime (0.1-30 THz) has become the subject of much attention due to its wide range of applications in diverse areas such as astronomy, imaging, spectroscopy, communications, and so on. Although significant progress has been recently achieved, there is still a need for semiconductor devices efficiently operating at these frequencies. This project will provide in a short-timeframe an answer for a long-standing problem of the terahertz community: How to achieve very sensitive terahertz detection in foundry-friendly, large-scale manufacturable, solid-state devices at room temperature. To achieve this goal, the proposed work aims to exploit Super-Steep-Subthreshold-Slope Fin-based Field Effect Transistors as efficient terahertz detectors. This project will be the first to perform research on terahertz applications of this emerging transistor technology and is expected to transform the terahertz technology landscape in the coming years. Indeed, the expectation is to provide more than two orders of performance gain in terahertz detection, which is of immense interest to the terahertz community. More generally, harvesting the unique properties of emerging transistor technologies for viable real-world applications is also of high interest to the semiconductor device community. This research vision is interlaced with the strong educational objective of mentoring new generations of graduate and undergraduate students in the field of electron devices, high frequency electronics, analog circuits, terahertz, and optics, stimulating their critical thinking and curiosity by providing them with hands-on experience in cutting-edge research. This is of significant importance given the future projected needs for highly trained engineers and scientists in the United States.This project aims at exploiting Super-Steep-Subthreshold-Slope Fin-based Field Effect Transistors as efficient terahertz detectors. The fundamental mechanism enabling a very sensitive terahertz response in these devices is their super-steep subthreshold slope (10mV/dec.), which is a result of a positive feedback induced by weak impact ionization and can lead to a very large responsivity. Preliminary data based on the measured direct current characteristics of fabricated devices predicts a much better performance in terms of both responsivity as well as noise equivalent power with respect to all the existing current room-temperature terahertz detector technologies, i.e., noise equivalent power ~ 0.01 pW/(Hz^0.5). Super-steep-slope Field Effect Transistors will be fabricated and configured as ultra-high-performance terahertz detectors. Thanks to its super-steep-slope response, this technology can promise more than two orders of magnitude larger responsivity than the thermally-limited 10 A/W responsivity of room-temperature FET and Schottky diode terahertz detectors, without increase in cost. This level of performance is not achievable with regular CMOS technologies. Moreover, when compared with other promising post-CMOS transistor technologies as terahertz detectors (such as tunnel FETs), these devices constitute a more robust platform since: (a) room-temperature demonstrations of super-steep-slope field effect transistors with direct current performance according to the requirements of terahertz detectors have been already demonstrated, (b) super-steep-slope field effect transistors are silicon based and 100% compatible with CMOS processes.