Sub-Surface Structural Damages in Laser-assisted Surface Nanostructuring: Experimental Characterization and Atomistic Modeling

激光辅助表面纳米结构中的次表面结构损伤：实验表征和原子建模

• 批准号: 0820747
• 负责人: Xinwei Wang
• 金额: $ 10.13万
• 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: 2008
• 资助国家: 美国
• 起止时间: 2008-02-01 至 2009-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0820747&HistoricalAwards=false
• 关键词: Sub; Surface; Structural; Damages; Laser

As a top-down nanofabrication technique, the laser-assisted scanning tunneling microscope (STM) provides a wide variety of potential applications in surface nano-repair, fabrication and characterization of nano- to microscale integrated nanoelectronics and nanophotonics, and machining and aligning of nanoparticles and nanotubes/wires. The nanoscale residual stress/strain and structural damages in surface nanostructures fabricated using laser-assisted STM can significantly change the local mechanical, thermal, optical, and electronic characteristics, thereby degrading the functionality and reliability of surface nanostructures. Targeting this critical problem, the objectives of the project are to (1) develop the knowledge base about the underlying physics in the formation of sub-surface nanoscale structural damages in surface nanostructuring with laser-assisted STM, and (2) explore and identify how and to what extent the experimental parameters affect the formation of sub-surface nanoscale structural damages. Significant insights into strain and structural damages at molecular/atomic levels in nanostructuring by laser-assisted STM will be attained using both scanning tunneling spectroscopy and high-resolution transmission electron microscopy. This represents the early attempts to quantitatively explore the characteristics of the residual strain and structural damages at such a small scale. This large-scale molecular dynamics simulation will provide fundamental and dynamic understanding of the development and propagation/migration of both stress/strain and structural damages in surface nanostructuring with laser-assisted STM. These strategically combined experimental and numerical investigations will reveal the correlations between residual strain and structural damages and varied experimental parameters.The anticipated outcomes are instrumental for minimizing residual stress/strain and structural damages and improving the function/performance and dependability of micro/nanoscale systems. Sufficient insights into the mechanisms and driving forces behind the formation of nanoscale structural damages will lead to the establishment of basic knowledge building blocks required for successful development of the nanostructuring technology with laser-assisted STM and its implementation to industries. Results of the research will be broadly disseminated through presentations at professional conferences, publications in highly visible refereed journals, across-department seminars, and a dedicated project website. The research results will be integrated into new courses "Heat Transfer at Nanoscales and in Ultra-short Time Domain" and "Introduction to Nanotechnology." Extensive undergraduate participation will be involved via summer research employment. Special efforts will be taken to recruit graduate and undergraduate students from groups traditionally underrepresented in higher education, particularly women and minorities. A specially designed website will be developed for instructional functions for K-12 students.

作为一种自上而下的纳米加工技术，激光辅助扫描隧道显微镜（STM）在表面纳米修复、纳米到微米级集成纳米电子学和纳米光子学的制造和表征以及纳米粒子的加工和排列方面提供了广泛的潜在应用和纳米管/线。使用激光辅助STM制造的表面纳米结构中的纳米级残余应力/应变和结构损伤可以显着改变局部机械、热、光学和电子特性，从而降低表面纳米结构的功能和可靠性。针对这一关键问题，该项目的目标是 (1) 开发有关激光辅助 STM 表面纳米结构中次表面纳米级结构损伤形成的基础物理的知识库，以及 (2) 探索和确定如何以及实验参数在多大程度上影响次表面纳米级结构损伤的形成。 使用扫描隧道光谱和高分辨率透射电子显微镜，可以对激光辅助 STM 纳米结构中分子/原子水平的应变和结构损伤产生重要的见解。这代表了在如此小规模下定量探索残余应变和结构损伤特征的早期尝试。这种大规模分子动力学模拟将为激光辅助 STM 表面纳米结构中应力/应变和结构损伤的发展和传播/迁移提供基本和动态的理解。这些策略性地结合实验和数值研究将揭示残余应变和结构损伤以及不同实验参数之间的相关性。预期结果有助于最大限度地减少残余应力/应变和结构损伤，并提高微/纳米级系统的功能/性能和可靠性。对纳米级结构损伤形成背后的机制和驱动力的充分了解将有助于建立成功开发激光辅助 STM 纳米结构技术及其在工业中实施所需的基础知识构建模块。 研究结果将通过在专业会议上的演讲、在知名参考期刊上发表文章、跨部门研讨会和专门的项目网站来广泛传播。研究成果将被纳入新课程“纳米尺度和超短时域传热”和“纳米技术导论”。本科生将通过暑期研究工作进行广泛的参与。将采取特别措施，从传统上在高等教育中代表性不足的群体中招收研究生和本科生，特别是女性和少数民族。将开发一个专门设计的网站，用于 K-12 学生的教学功能。