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

代谢物、气体和许多化学品在结构上是独一无二的，在红外光谱带上显示出独特的吸收指纹。使用便携式设备对这种光谱进行准确的检测和跟踪具有巨大的潜力，可以实现许多应用，包括实时健康监测、气体检测、光谱分析、成像、危险物质的识别等。普通的红外光谱仪依赖于傅里叶变换系统(FTIR)，这些系统体积庞大、价格昂贵、与集成电路不兼容，不适合实际应用。在这里，基于美国和台湾集团的协作努力，将展示一种在室温下运行的芯片上红外光谱系统，该系统能够使用大量通道扫描~1.5μm到10μm。该系统依赖于一系列美国制造的小型化和光谱选择性红外传感器，以及台湾制造的实现最先进噪声抑制和审问技术的cmos芯片的集成。拟议的片上红外光谱平台是红外技术领域向前迈出的重要一步，超越了笨重而昂贵的基于傅立叶变换的光谱仪，进入了小型化、负担得起和准备批量生产的设备。这类系统的潜在应用包括传感、通信、成像和光谱分析等。在教育方面，该项目将为研究生和本科生提供关于各种科学领域的多学科培训，如CMOS技术、红外传感、机械谐振器、超材料以及器件制造和表征；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；鼓励妇女和西班牙裔学生--个人投资机构可以作为榜样--参与和保留STEM和研究。更进一步，该项目将促进美国和台湾研究人员之间的合作，并为长期合作伙伴关系和科学互动奠定基础。该项目的目标是展示一种片上红外光谱系统，该系统能够使用大量并行通道扫描~1.5μm到10μm，同时表现出能够超越在室温下运行的竞争技术的性能。为此，将在加州大学戴维斯分校净化室的单个芯片上制造大型光谱选择性红外传感器阵列，而在台积电研究所(TSRI)制造的芯片上实施射频询问和噪声抑制方案。TSRI还将进行不同类型的集成和打包。关键的构建模块是基于自由空间立式微电子机械系统(MEMS)顶部的纳米图案化超薄和高Q亚表面的红外探测器，以有效地吸收具有所需光谱分布的光。每个MEMS旨在实现高机械品质因数并吸收目标波长，它将在共振时由射频信号激励，其相位和幅度随着吸收的红外功率而变化。为了提高系统性能，探测器将在每个释放的腔体中包括两个MEMS，一个用作参考，另一个用作传感器。利用I/Q信号作为参考/传感路径，将获得并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、机械、光学、热)以及电子读出电路噪声和非理想情况。除了显著降低噪声外，使用CMOS技术还将允许同时询问芯片上更大的并行传感器阵列，并将它们的信号多路传输到输出通道。该计划将奠定基础，并展示小型化、超灵敏、低噪声、片上红外光谱系统，能够与在室温下运行的最先进的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NSF的法定使命，并通过使用基金会的智力优势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.