Exploring local confinement of ultrafast light to enable nondestructive acoustic metrology at the nanoscale

探索超快光的局部限制以实现纳米级无损声学计量

• 批准号: 1611356
• 负责人: Oluwaseyi Balogun
• 金额: $ 32.95万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-15 至 2020-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1611356&HistoricalAwards=false
• 关键词: Exploring; local; confinement; ultrafast; light

This project will explore light focusing schemes to confine light at the nanoscale and develop a novel instrumentation that will enable detection of nanoscale structural defects in modern electronic devices. The proposed approach is nondestructive and noninvasive and relies on a combination of optical and elastic wave propagation. Acoustic imaging methods are well established methods for visualizing interior regions of a solid material using elastic waves. Acoustic imaging is commonly used for failure analysis and assessment of process conditions in semiconductor manufacturing. Unfortunately, the spatial resolution of acoustic imaging methods is limited to the micrometer scale due to diffraction, which is a major short coming that this project seeks to address. In order to overcome the limited resolution, photonic metamaterials will be explored to create an array of bright nanoscale optical probes that will be used to detect high frequency (0.3 -1 THz) elastic waves. Waves in this frequency range have wavelengths of a few tens of nanometers, and are extremely sensitive to the presence of nanoscale defects like voids, cracks, and inclusions. The proposed scheme will provide access to extreme spatial resolution ( 20 nm) and temporal resolution (~ 1 picosecond) for probing elastic wave propagation, and will provide parallel detection capabilities to facilitate rapid imaging of micro- and nano-electronic structures. Furthermore, the optical detection approach can be applied broadly beyond semiconductor imaging. These applications include molecular imaging and biochemical sensing for medical therapy and drug development. The project will create opportunities for undergraduate and graduate students to participate in multidisciplinary research in the areas of nanomechanics and near-field optics. The research outputs of the project will be used to design an inquiry based nanotechnology applet on nanomechanics for use in a high-school physics classroom.This project will address technical barriers in conventional acoustic imaging methods for sensing and nanometrology of semiconductor electronic devices through the development of novel instrumentation that integrates plasmonic metasurfaces with picosecond laser-based ultrasonics. The ultrasonic approach relies on the use of a femtosecond pump laser source for generation of ultrashort (bandwidth of up to 1 THz) elastic wave pulses. The elastic pulses will be monitored with picoseconds time-resolution using the pump-and-probe time-domain spectroscopy approach. The metasurface which is comprised of a two dimensional array of plasmonic nanoantenna dimers will enable efficient confinement of a femtosecond probe laser on a subwavelength scale, by exploiting electromagnetic wave resonances within the nanometer sized dimer gaps. Each dimer will serve as a nanoscale optical probe for detection of elastic waves on the sample surface. Towards this end, three specific research tasks will be addressed: (1) investigation of the influence of transient mechanical deformations (elastic waves and vibrations) at picoseconds timescales on the nano-confinement and enhancement in the plasmonic nanoantennas, (2) design and implementation of locally addressable arrays of nanoantennas to enable parallel detection of elastic waves on nanoscale areas without probe-scanning, and (3) investigation and implementation of ultrafast laser generation and detection of elastic waves in model electronic devices with high aspect ratio nanostructures for detection of buried nanoscale defects. Furthermore, an inverse model based on the time-reversal technique will be developed for defect identification, localization, and sizing. These tasks will advance existing understanding of the local interaction of ultrafast light and ultrahigh frequency (THz) elastic waves in semiconductor devices. Ultimately, these undertakings will facilitate the development of a nanometrology and imaging approach that permits noninvasive measurements in semiconductor devices that cannot be achieved using current technologies.

该项目将探索光聚焦方案，以限制纳米级的光线，并开发一种新颖的仪器，该仪器将能够检测现代电子设备中的纳米级结构缺陷。所提出的方法是无损和无创的，依赖于光学和弹性波传播的组合。声学成像方法是使用弹性波可视化固体材料内部区域的良好建立方法。声学成像通常用于半导体制造中过程条件的故障分析和评估。不幸的是，由于衍射，声学成像方法的空间分辨率仅限于千分尺尺度，这是该项目寻求解决的主要简短。为了克服有限的分辨率，将探索光子超材料，以创建一系列明亮的纳米级光学探针，该探针将用于检测高频（0.3 -1 THz）弹性波。该频率范围内的波有几十纳米的波长，并且对存在纳米级缺陷（如空隙，裂缝和夹杂物）非常敏感。提出的方案将提供对极端空间分辨率（20 nm）和时间分辨率（〜1 picsecond）进行探测弹性波传播的访问，并将提供并行检测能力，以促进微型和纳米电子结构的快速成像。此外，光学检测方法可以广泛应用于半导体成像。这些应用包括用于药物治疗和药物开发的分子成像和生化感测。该项目将为本科生和研究生创造机会参加纳米力学和近场光学领域的多学科研究。该项目的研究成果将用于设计基于询问的纳米技术小程序，用于纳米力学，用于高中物理学教室。该项目将通过新颖的仪器与超级元素的开发进行超级仪表仪的开发，以使仪器的开发与超级元素进行效率picosecececececececececececects contersications的传统声学成像方法的技术障碍。超声波方法依赖于使用飞秒泵激光源来生成超短型（最高1 THz）弹性波脉冲的弹性波脉冲。弹性脉冲将使用泵和探针的时间域光谱方法使用Picseconds时间分辨进行监测。由等离子纳米烷二聚体的二维阵列组成的元表面将通过利用纳米表中的二聚体二聚体差距内的电磁波共振，在亚波长度上有效地限制在次波长度上的有效限制。每个二聚体将用作纳米级光学探针，以检测样品表面上的弹性波。为此，将解决三个具体的研究任务：（1）对Picseconds时尺度上瞬时机械变形（弹性波和振动）的影响，对等离激元纳米ant的纳米结合和增强的影响（2）（2）不启用Nano Annoantenn的纳米级驱动器的纳米式驱动器的影响，以实现nanomisce的驱动器。探针扫描，（3）在具有高纵横比纳米结构的模型电子设备中，对超快激光生成的研究和实施，用于检测埋藏的纳米级缺陷。此外，将开发基于时间反转技术的逆模型用于缺陷识别，定位和尺寸。这些任务将进一步了解半导体设备中超快光和超高频率（THZ）弹性波的局部相互作用。最终，这些事业将促进纳米测量和成像方法的开发，该方法允许在半导体设备中进行无创测量，这些测量无法使用当前技术来实现。