Development of Scanning Photothermal Microscope for Nanoscale Sub-surface Structural Defect Characterization

开发用于纳米级次表面结构缺陷表征的扫描光热显微镜

• 批准号: 0926704
• 负责人: Xinwei Wang
• 金额: $ 26.88万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0926704&HistoricalAwards=false
• 关键词: Development; Scanning; Photothermal; Microscope; Nanoscale; Development; Scanning; Photothermal; Microscope; Nanoscale

The objectives of this project are to conduct research on break-through sub-surface structural defect characterization based on laser-coupled scanning probe photothermal concept to achieve depth profiling with nanoscale spatial resolution. The proposed sub-surface characterization features nanoscale spatial resolution using frequency-modulated near-field laser focusing and thermal expansion sensing. Research will be carried out to study the physical phenomena in sub-surface characterization, including near-field laser focusing, nanoscale heating, thermal transport, and elastic surface displacement. A physical model will be developed for dynamic surface displacement under periodical nanoscale laser heating.Upon accomplishment, the proposed research will open a new compelling way for sub-surface structural defect characterization with nanoscale spatial resolution while most of the existing scanning probe technologies are for characterizing surface properties. The surface displacement sensing in the proposed characterization takes advantage of the atomic force acoustic mechanism and features fast response. By varying the modulation frequency of the laser beam incident on the scanning probe tip, we will be able to vary the characterization length and diagnose sub-surface defect of different depth. Furthermore, deliverables will include a comprehensive physical model to interpret the characterization data to obtain quantitative information about the size and depth of structural defect. The strong capability of the proposed sub-surface characterization will make it have broad applications in structural diagnostics of nanostructured materials and evaluation of sub-surface structure in nanoscale material processing. Results of the proposed research will be disseminated through broad publications. Furthermore, the research results will be integrated into new course development and conventional class teaching at Iowa State University. Extensive undergraduate participation via summer research will be arranged. Outreach services to K-12 students will be facilitated through the ESPP program of Iowa State University.

该项目的目标是基于激光耦合扫描探针光热概念进行有关突破性地下结构缺陷表征的研究，以通过纳米级空间分辨率实现深度分析。提出的地下表征具有纳米级的空间分辨率，使用频率调节的近场激光聚焦和热膨胀感应。将进行研究以研究地下表征的物理现象，包括近场激光聚焦，纳米级加热，热传输和弹性表面位移。在周期性的纳米级激光加热下，将开发一个物理模型。所提出的表征中的表面位移传感利用了原子力的声学机制，并具有快速响应。通过改变入射在扫描探针尖端上激光束的调制频率，我们将能够改变不同深度的表征长度和诊断的地下缺陷。此外，可交付成果将包括一个全面的物理模型来解释特征数据，以获取有关结构缺陷大小和深度的定量信息。所提出的地下表征的强大能力将使其在纳米结构材料的结构诊断中具有广泛的应用，并评估纳米级材料处理中的地下结构。拟议研究的结果将通过广泛的出版物传播。此外，研究结果将纳入爱荷华州立大学的新课程开发和常规课程教学。将安排通过夏季研究的广泛的本科参与。爱荷华州立大学的ESPP计划将为K-12学生提供外展服务。