Stress and Structure Evolution During Formation of Polycrystalline Metallic Films: From Adatoms to Coalescence

多晶金属薄膜形成过程中的应力和结构演变：从吸附原子到聚结

• 批准号: 0302044
• 负责人: Carl Thompson
• 金额: --
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0302044&HistoricalAwards=false
• 关键词: Stress; Structure; Evolution; During; Formation

The grant explores a clear understanding of the atomic processes involved in film formation. New stress measurement capabilities allow studies of adatom-substrate interactions, as well as adatom-adatom interactions in the sub-monolayer regime. An objective of the proposed study is to correlate in-situ measurements of stress evolution during growth and during growth interruptions with ex-situ STM, ex-situ TEM, and in-situ TEM observations of structure evolution. Experiments involving both epitaxial and polycrystalline film growth will be conducted. Detailed effects of populations of adatoms will be simulated using molecular dynamics and ab-initio approaches. Simulation results will be compared with measured forces in epitaxial systems. Through these studies, the separate effects of changing adatom concentrations and cluster formation will be determined. Experimental studies of later stages of growth will allow separate characterization of the effects of cluster coarsening, growth, and coalescence. Measurements of stress evolution, when correlated with studies of structure evolution, will provide a powerful tool for in-situ real-time kinetic analyses of the various atomistic processes involved in the earliest stages of film formation.%%%The study will have applications in a wide array of micro and nano-devices and systems including microelectronic, nanomagnetic, and micro- and nanoelectromechanical systems where the properties, performance, and reliability of nanocrystalline metallic structures are strongly affected by their stress state and defect structures. Results from this and related studies will be disseminated through a variety of graduate and undergraduate courses within the parent institution, as well as through partnerships with other universities and through summer courses for professional engineers. The research will be carried out with collaborators at MIT and in Singapore, and will indirectly support the research activities of the research groups of the faculty involved. Research results will be disseminated through publications and presentations, as well as via the Internet, and will be incorporated in software tools that are used directly by engineers.***

该补助金探索了对薄膜形成中所涉及的原子过程的清晰理解。新的应力测量能力允许研究adatom-衬底相互作用，以及adatom-adatom相互作用的亚单层制度。建议的研究的一个目的是在生长过程中，并在生长中断与非原位STM，非原位TEM，和原位TEM观察结构演变的应力演化的原位测量。实验涉及外延和多晶薄膜生长将进行。将使用分子动力学和从头算方法模拟吸附原子群体的详细影响。模拟结果将与外延系统中测得的力进行比较。通过这些研究，将确定改变吸附原子浓度和簇形成的单独影响。后期的增长阶段的实验研究将允许单独表征集群粗化，增长和合并的影响。当应力演化的测量与结构演化的研究相关联时，将为原位实时动力学分析膜形成的早期阶段所涉及的各种原子过程提供强有力的工具。该研究将在广泛的微和纳米器件和系统中应用，包括微电子，纳米磁以及微和纳米机电系统，其中纳米晶体金属结构的性质，性能和可靠性受到其应力状态和缺陷结构的强烈影响。这项研究和相关研究的结果将通过母机构内的各种研究生和本科生课程，以及通过与其他大学的伙伴关系和通过专业工程师的暑期课程传播。这项研究将与麻省理工学院和新加坡的合作者一起进行，并将间接支持有关学院研究小组的研究活动。研究结果将通过出版物和演示文稿以及互联网传播，并将纳入工程师直接使用的软件工具中。