ACED Fab: On-chip CMOS-MEMS Infrared Spectroscopy Systems

代谢物、气体和许多化学物质在结构上是独特的，在红外光谱带中表现出独特的吸收指纹。使用便携式设备对这种光谱进行精确检测和跟踪具有巨大的潜力，并将实现许多应用，包括实时健康监测、气体检测、光谱学、成像、有害物质识别等。普通红外光谱仪依靠傅里叶变换系统（FTIR），体积庞大，价格昂贵，与集成电路不兼容，不适合实际应用。在这里，基于美国和台湾团队之间的协同合作努力，将展示在室温下工作的片上红外光谱系统，该系统能够使用大量通道扫描~ 1.5μm到10 μm。该系统依赖于集成一系列在美国制造的小型化和光谱选择性红外传感器，以及在台湾制造的CMOS芯片，这些芯片实现了最先进的噪声抑制和询问技术。提出的片上红外光谱平台构成了红外技术领域的重要一步，超越了笨重和昂贵的基于傅立叶变换的光谱仪，进入小型化，经济实惠，可批量生产的设备。这种系统的潜在应用包括传感、通信、成像和光谱学等。在教育方面，该项目将为研究生和本科生提供多种科学领域的多学科培训，如CMOS技术、红外传感、机械谐振器、超材料、器件制造和表征；将研究成果与教育活动结合起来，包括将研究内容纳入研究生课程，并通过期刊论文和科学会议广泛传播；并鼓励女性和西班牙裔学生参与和保留STEM和研究，这些pi可以作为榜样。除此之外，该计划将促进美国和台湾研究人员之间的合作，并为长期伙伴关系和科学互动奠定基础。该项目的目标是展示一种能够使用大量并行通道扫描~ 1.5μm至10 μm的片上红外光谱系统，同时展示能够超越室温下工作的竞争技术的性能。为此，将在加州大学戴维斯分校洁净室的单芯片上制造大型阵列光谱选择性红外传感器，而RF询问和噪声抑制方案将在台湾半导体研究所（TSRI）制造的CMOS芯片上实现。异构集成和封装也将在TSRI进行。其关键组成部分是在自由空间站立式微机电系统（mems）上基于纳米图像化超薄和高q超表面的红外探测器，以有效吸收具有所需光谱分布的光。每个MEMS都是为了实现高机械质量因子和吸收目标波长而设计的，将被射频信号以共振方式激发，射频信号的相位和幅度随吸收的红外功率而变化。为了提高系统性能，探测器每个释放腔将包括两个MEMS，一个作为参考，另一个作为传感器。利用参考/传感路径的I/Q信号，将获得和处理两个单元的相位/幅度变化，以高度抑制共模和环境噪声（电气，机械，光学，热）以及电子读出电路噪声和非理想性。除了显著降低噪声外，CMOS技术的使用将允许在芯片上同时询问更大的并行传感器阵列，并将其信号复用到输出通道。该项目将奠定基础，展示小型化、超灵敏、低噪音的片上红外光谱系统，该系统能够在室温下与最先进的FTIR技术竞争，同时加强美国和台湾之间的伙伴关系和科学互动。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。

Metabolites, gases, and many chemicals are structurally unique and exhibit distinctive absorptive fingerprints in the infrared spectrum band. The accurate detection and tracking of such spectrum using portable devices carry enormous potential and would enable many applications, including real-time health monitoring, gas detection, spectroscopy, imaging, the identification of hazardous materials, etc. Common infrared spectrometers rely on Fourier Transform system (FTIR) that are bulky, expensive, incompatible with integrated circuits, and unsuitable for real-life applications. Here, rooted on a synergetic collaborative effort between U.S. and Taiwan groups, an on-chip infrared spectroscopy system operating at room temperature and able to scan from ~ 1.5μm to 10 μm using a large number of channels will be demonstrated. The system relies on the integration of an array of miniaturized and spectrally-selective infrared sensors fabricated in the US, and CMOS chips fabricated in Taiwan that implement state of the art noise-suppression and interrogation techniques. The proposed on-chip infrared spectroscopy platform constitutes a significant step forward in the field of infrared technologies, moving beyond bulky and expensive Fourier Transform-based spectrometers into miniaturized, affordable, and mass-production ready devices. The potential applications enabled by such systems include sensing, communications, imaging, and spectroscopy, among many others. On the educational front, this project will provide multidisciplinary training to graduate and undergraduate students on a variety of scientific areas such as CMOS technologies, infrared sensing, mechanical resonators, metamaterials, and device fabrication and characterization; integrate research results with education activities, including the incorporation of research content in graduate courses and its broad dissemination through journal papers and scientific conferences; and encourage the participation and retention of women and Hispanic students - the PIs can serve as role model- in STEM and research. Moving beyond, this program will foster the collaboration between US and Taiwan researchers and set the foundations for long-term partnerships and scientific interactions. The goal of this project is to demonstrate an on-chip infrared spectroscopy system able to scan from ~ 1.5μm to 10 μm using a massive number of parallel channels while exhibiting a performance able to surpass competing technologies operating at room temperature. To this purpose, a large array spectrally-selective infrared sensors will be fabricated on a single chip at the UC Davis cleanroom, whereas RF interrogating and noise-suppression schemes will be implemented on a CMOS chip that will be fabricated at the Taiwan Semiconductor Research Institute (TSRI). Heterogeneous integration and packaging will also be carried out at the TSRI. The key building-block is an infrared detector based on nano-patterning ultrathin and high-Q metasurfaces on top of free-space standing microelectromechanical systems (MEMSs) to efficiently absorb light with desired spectral distribution. Each MEMS, designed to achieve a high mechanical quality factor and to absorb targeted wavelengths, will be excited at resonance by a RF signal whose phase and amplitude changes with the absorbed infrared power. To enhance the system performance, the detector will include two MEMS per released cavity, one serving as the reference and the other as the sensor. Exploiting I/Q signals for reference/sensing paths, the phase/amplitude variations of both units will be obtained and processed to highly suppress common mode and environmental noises (electrical, mechanical, optical, thermal) as well as the electronic readout circuit noises and non-idealities. In addition to significant noise reduction, the use of CMOS technology will permit to interrogate simultaneously a larger array of parallel sensors on a chip, and to multiplex their signals towards an output channel. This program will lay the foundational groundwork and demonstrate miniaturized, ultra-sensitive, low-noise, on-chip IR spectroscopy systems able to compete with state-of-the-art FTIR technologies operating at room temperature while strengthening the partnership and scientific interactions between USA and Taiwan.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.