Nanoscale Structure and Dynamics of Self-Organized Steps on Silicon Surfaces

硅表面自组织台阶的纳米级结构和动力学

• 批准号: 0074416
• 负责人: Jonathan Pelz
• 金额: --
• 依托单位: Ohio State University Research Foundation -DO NOT USE
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-01 至 2005-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0074416&HistoricalAwards=false
• 关键词: Nanoscale; Structure; Dynamics; Self; Organized

This project aims for greater understanding of spontaneous formation, self-organization, and long-range pattern formation of steps on silicon surfaces. The approach includes: (1) Surface decomposition of diborane (B2H6) to directly add boron to the surface in a controlled manner, instead of using heavily boron-doped Si wafers. "Hot" scanning tunneling microscopy (STM) will be used to make real-time atomic-resolution measurements of B2H6 decomposition, boron incorporation (with and without an additional Si flux), and resulting atomic-scale step formation and/or surface roughening. (2) "Flattened" Si(001) substrates (with terraces up to 20 um wide) will be used to study long-range step organization phenomena so as to avoid complications imposed by "vicinal" steps. Flattened Si(001) substrates permit experiments to study directly the role of long-range relaxation effects in the step formation and organization process, and to determine the equilibrium shape of large-scale step "superstructures" that form on the terrace. (3) Low energy electron microscopy (LEEM) will be used for real-time studies of large-scale step formation as boron is added to the surface. A second line of research concerns large-scale organization of steps on Si(001) surfaces due to surface electromigration forces. Quantitative measurement and modeling studies of electromigration phenomena on Si(001) surfaces include several approaches. (1) "Dimpled" Si wafer substrates to directly study how electromigration phenomena depend on the angle between the local surface miscut and an applied current. (2) Detailed measurement and modeling of "crossing steps" on the Si(001) surface will be done to extract quantitative information about the "effective charge" (and its possible anisotropy) of surface silicon atoms. (3) LEEM measurements of surface electromigration phenomena will be conducted. Real-time measurements of crossing-step evolution will be used to directly test crossing-step models, and extract quantitative information about the important surface processes that produce surface electromigration phenomena. The research will make use of three existing ultra-high vacuum (UHV) STM facilities (a commercial variable-temperature STM system and two custom-built room-temperature STM systems), and an existing commercial atomic force microscopy (AFM) system. Collaborative studies at Arizona State University will use two separate UHV LEEM systems.%%% The project addresses basic research issues in a topical area of materials science with high technological relevance. These studies will improve fundamental understanding of silicon surface processes, which are key to several issues in ultimate limits of silicon-based microelectronics miniaturization. Experimental tools are now available to allow atomic level observation of elementary surface processes which when better understood allow advances in fundamental science and technology. An important feature of the program is the integration of research and education through the training of students in a fundamentally and technologically significant area. ***

这个项目旨在更好地理解硅表面台阶的自发形成、自组织和长距离图案形成。该方法包括：（1）乙硼烷（B2 H6）的表面分解，以受控的方式将硼直接添加到表面，而不是使用重掺杂硼的Si晶片。“热”扫描隧道显微镜（STM）将用于实时原子分辨率测量B2 H6分解，硼掺入（有和没有额外的Si通量），以及由此产生的原子级台阶形成和/或表面粗糙化。(2)“平坦”Si（001）衬底（具有高达20 μ m宽的台阶）将用于研究长程台阶组织现象，以避免“邻近”台阶造成的复杂性。平整的Si（001）衬底允许实验直接研究长程弛豫效应在台阶形成和组织过程中的作用，并确定在平台上形成的大尺度台阶“超结构”的平衡形状。(3)低能电子显微镜（LEEM）将用于实时研究大规模的步骤形成硼添加到表面。第二条研究路线涉及由于表面电迁移力而在Si（001）表面上形成的大规模台阶组织。Si（001）表面电迁移现象的定量测量和模拟研究包括几种方法。(1)“凹陷”硅晶片衬底，直接研究电迁移现象如何依赖于局部表面误切和施加电流之间的角度。(2)详细的测量和建模的“交叉步骤”的Si（001）表面上将进行提取有关的“有效电荷”（及其可能的各向异性）的表面硅原子的定量信息。(3)将对表面电迁移现象进行LEEM测量。实时测量的交叉步骤演变将被用来直接测试交叉步骤模型，并提取定量信息的重要表面过程，产生表面电迁移现象。该研究将利用三个现有的超高真空（UHV）STM设施（一个商业变温STM系统和两个定制的室温STM系统）和一个现有的商业原子力显微镜（AFM）系统。亚利桑那州立大学的合作研究将使用两个独立的UHV LEEM系统。%该项目涉及材料科学专题领域的基础研究问题，具有高度的技术相关性。这些研究将提高对硅表面过程的基本理解，这是硅基微电子微型化极限中几个问题的关键。现在已有实验工具，可以在原子水平上观察基本表面过程，如果能更好地了解这些过程，就可以在基础科学和技术方面取得进展。该计划的一个重要特点是通过在一个基本和技术上重要的领域对学生进行培训来整合研究和教育。***