In-situ X-ray Studies of Surface Structure during Plasma Processing

等离子体加工过程中表面结构的原位 X 射线研究

• 批准号: 0208011
• 负责人: Karl Ludwig
• 金额: $ 32.19万
• 依托单位: Trustees of Boston University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2005-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0208011&HistoricalAwards=false
• 关键词: situ; ray; Studies; Surface; Structure

This project address fundamental issues associated with surface structure and its relationship to the plasma environment in plasma-based processing of electronic materials. The approach is to use real-time, in-situ, synchrotron- based x-ray diffraction to investigate the surface and near-surface structure of silicon and compound semiconductors (GaAs and GaN) undergoing chlorine-based plasma processing. After gaining experience using real-time x-ray scattering to understand silicon surface structure during processing, compound semiconductors, GaAs(100)/(110) and GaN(0001) (i.e. polar surface vs. non-polar surfaces) will be addressed. The atomic structure of the surfaces will be examined during exposure to the plasma, including questions of the extent to which surface reconstruction remains in the compound semiconductors in this environment. The evolution of the surface morphology during plasma processing will be investigated using grazing-incidence small-angle x-ray scattering (GISAXS). The evolution of step structure (bunching vs. anti-bunching) on the compound semiconductor surfaces during exposure to the plasma will be studied as a function of substrate miscut size and direction. In addition, regimes of layer-by-layer removal vs. step retraction will be examined to better understand their relationship to the surface structure. The evolution of the GaAs surface stoichiometry will be followed in real time with x-ray fluorescence. In silicon, the density and depth of the damaged chlorinated surface layer will be studied and compared with existing simulations. The results of experiments performed in the x-ray portion of the proposed work will be correlated to independent characterization efforts performed at BU and NRL. Post- processing surface morphology will be examined with AFM. Surface damage will also be characterized ex-situ using C-V measurements, transmission line measurements of contact resistances to processed surfaces and photoreflectance spectroscopy. The proposed research program focuses on the fundamental questions of the relation between plasma processing conditions and atomic surface structure and is expected to serve as a stimulus for further development of theory and simulation. The new knowledge gained will be important for future rational development of new processing techniques, especially in novel materials.%%% The project addresses fundamental research issues in areas of electronic materials science having technological relevance. An important feature of the project is the strong emphasis on education, and the integration of research and education. The research program provides excellent opportunities for hands-on experience in the use of sophisticated scientific equipment. The broad resources, and collaborative aspects, provide special opportunities for education and training of graduate and undergraduate students involved in interdisciplinary forefront research. ***

该项目解决了与表面结构相关的基本问题及其与电子材料基于等离子体的处理中的血浆环境的关系。该方法是使用实​​时的，原位，同步加速器基于X射线衍射来研究经过基于氯的血浆处理的硅和复合半导体（GAAS和GAN）的表面和近表面结构。在使用实时X射线散射获得经验后，将解决复合半导体，GAAS（100）/（110）和GAN（0001）（即极性表面与非极性表面）的经验。在暴露于等离子体的过程中，将检查表面的原子结构，包括在这种环境中表面重建保留在复合半导体中的程度的问题。血浆过程过程中表面形态的演变将使用放牧的小角度X射线散射（GISAXS）研究。在暴露于等离子体期间，将在复合半导体表面上的步长结构的演变（束抗管）的演变作为底物误差大小和方向的函数。此外，将检查逐层去除与阶梯缩回的状态，以更好地了解它们与表面结构的关系。 X射线荧光将实时遵循GAAS表面化学计量的演变。在硅中，将研究受损的氯化表面层的密度和深度，并将其与现有模拟进行比较。在提出的工作的X射线部分进行的实验结果将与在BU和NRL上执行的独立表征工作相关。加工后表面形态将与AFM一起检查。还将使用C-V测量值，传输线测量加工表面的接触电阻和光逆透射光谱法对表面损伤进行表征。拟议的研究计划着重于等离子体处理条件与原子表面结构之间关系的基本问题，并有望作为进一步发展理论和模拟的刺激。获得的新知识对于未来的新处理技术的合理发展将很重要，尤其是在新型材料中。%%％该项目解决了具有技术相关性的电子材料科学领域的基本研究问题。该项目的一个重要特征是对教育以及研究和教育的融合非常重视。该研究计划为使用复杂的科学设备提供了实践经验的绝佳机会。广泛的资源和协作方面为研究生和本科生的教育和培训提供了特殊的机会，参与了跨学科的前沿研究。 ***