Toward Fundamental Understanding: Correlating the Gas-Phase, Surface, and Gas-Surface Interface in Halogenated Plasma Systems

该项目由美国国家科学基金会/美国能源部基础等离子体科学与工程伙伴关系资助，其重点是提高对卤化等离子体处理过程中表面发生的基本化学过程的理解。这些系统被广泛用于蚀刻和沉积高性能材料，并将继续用于制造下一代集成电路（IC）材料。材料的等离子体加工在具有定制表面性能的高性能材料的广泛应用中已成为必不可少的。重点是阐明这些系统中的基本分子水平化学。主要实验工具是我们独特的基于激光的自由基与表面相互作用成像（IRIS）技术，该技术为等离子体物种提供了稳态表面相互作用数据。IRIS设备计划进行的两项改进是热丝化学气相沉积源，以提供无离子分子束，以及冷却衬底支架，以达到衬底温度300 K。气相诊断和表面表征也将用于提供整个等离子体系统的完整图像。总的来说，这些实验将产生其他实验技术无法获得的关于等离子体表面界面的至关重要的数据。这项研究的智力价值在于对卤化等离子体系统的知识和基本理解有可能取得重大进展。IRIS表面相互作用测量将仔细地与气相和表面分析数据相关联，以提供关于等离子体表面界面的几乎完整的一套信息。等离子体的内部和动能测量将提供其他技术无法获得的能量分配机制的见解。本研究内在的跨学科性质将为学生提供化学、工程和材料科学方面的广泛接触和教育，超越化学的传统界限。这项研究更广泛的影响在于增加了对卤化等离子体蚀刻和沉积过程中发生的化学过程的理解。这些系统被认为是重要的科学和技术相关的过程，具有广泛的应用，需要高性能材料，如集成电路生产和涂料技术。更全面地了解这些系统中潜在的化学成分，可能会导致制造业的改进，并对许多行业产生巨大的经济影响。此外，PI致力于扩大代表性不足群体的参与；她经常管理一个研究小组，其中女性或少数族裔同事占50%。PI一直是该机构材料计划发展的组成部分，并计划与工作一起开展额外的教育活动。

The focus of this project, funded through the NSF/DOE Partnership in Basic Plasma Science and Engineering, is to improve understanding of the fundamental chemical processes that occur at surfaces during plasma processing using halogenated plasmas. These systems are widely used to etch and deposit high performance materials, and will continue to be employed for manufacturing of next generation integrated circuit (IC) materials. Plasma processing of materials has become indispensable in a wide range of applications where high-performance materials with tailored surface properties are employed. The focus is on elucidating fundamental, molecular-level chemistry in these systems. The primary experimental tool is our unique laser-based Imaging of Radicals Interacting with Surfaces (IRIS) technique, which provides steady-state surface interaction data for plasma species. Two modifications planned for the IRIS apparatus are a hot-filament chemical vapor deposition source to provide an ion-free molecular beam, and a cooled substrate holder to access substrate temperatures 300 K. Gas-phase diagnostics and surface characterization will also be employed to provide a complete picture of the entire plasma system. Collectively, the experiments will produce critically important data on the plasma-surface interface unobtainable through other experimental techniques.The Intellectual Merit of the research lies in the potential for significant advancement in knowledge and basic understanding of halogenated plasma systems. IRIS surface-interaction measurements will be carefully correlated with gas-phase and surface analysis data to provide a virtually complete set of information on the plasma-surface interface. Internal and kinetic energy measurements for plasma species will provide insight into energy partitioning mechanisms unobtainable with other techniques. The intrinsic interdisciplinary nature of this research will afford students a broad exposure to and education in chemistry, engineering, and materials science, beyond the traditional boundaries in chemistry. The Broader Impacts of the research lie in the increased understanding of chemical processes occurring during etching and deposition from halogenated plasmas. These systems are recognized as important scientific and technologically-relevant processes with a wide range of applications where high performance materials are needed such as IC production and coatings technologies. A more complete understanding of the underlying chemistry in these systems could lead to manufacturing improvements with enormous economic impact across many industries. Furthermore, the PI is committed to broadening participation of underrepresented groups; she routinely supervises a research group with 50 percent female or underrepresented minority coworkers. The PI has been integral to development of the institution's materials program and plans additional educational activities with the work.