Control of Microtopography at Silicon Surfaces and Interfaces

这个项目解决了硅和其他半导体表面缺陷的性质，并探索了在原子水平上控制表面和界面形貌的方法。研究包括表面原子扩散、表面原子台阶的能量学和动力学、氧化诱导应变以及表面和界面形貌的详细控制。用扫描隧道显微镜和低能电子显微镜观察了原子台阶运动与整体表面形状演变之间的关系。这一结果有望对基础表面科学以及先进半导体器件和电路的制造有所裨益。这项研究可能有助于异质磁系统中界面的设计和控制，例如也用于磁阻应用中。具有预定的原子尺度特征阵列的表面在制造生物传感器的图案化衬底方面也可能是有价值的。该项目的主要目标是更全面地了解硅形态控制所涉及的基本工艺，并探索这些工艺在其他材料中的推广和应用。该项目的具体目标包括：1)研究通过气相沉积在Si(001)和Si(111)上形成原子平坦台面结构的温度和生长速率条件，以及使用化学腐蚀作为升华替代方法的相关工作。2)通过原子力显微镜和扫描隧道显微镜观察，研究了具有极大台阶的淬火硅表面在高温下存在的点缺陷类型。3)开发在硅和其他衬底上制作潜在有用的台阶图案作为吸附或沉积结构的模板的方法。将寻求生物分子和磁性层的应用。4)用X射线技术监测被禁反射的强度--类似于RHEED振荡，研究了原子扁平硅上氧化物生长的动力学。%该项目解决了材料科学中具有高度技术相关性的主题领域的基础研究问题。该计划的一个重要特点是通过在一个具有根本意义和技术意义的领域对学生进行培训，将研究和教育结合起来。该项目通过前沿的高度协作的研究环境，通过独特的教育体验，帮助学生发展技术、沟通和组织/管理技能。该项目的主要合作者包括康奈尔大学的研究人员C.C.Umbach博士(材料科学与工程)、J.Engstrom教授(化学。)、R.Headrick博士(国际象棋)、M.Hines教授(化学)、R.Tromp博士(IBM)和N.Bartelt博士(Sandia)。***

This project addresses properties of defects at silicon and other semiconductor surfaces and explores methods to control the topography of surfaces and interfaces at the atomic level. The research involves the study of surface atomic diffusion, the energetics and dynamics of surface atomic steps, oxidation-induced strain and detailed control of surface and interface morphology. Scanning tunneling microscopy and low energy electron microscopy are used to observe the connection between atomic step motion and the evolution of overall surface shape. Results are expected to be of interest to fundamental surface science and in the fabrication of advanced semiconductor devices and circuits. The research may contribute to the design and control of interfaces in heterogeneous magnetic systems such as are used in magneto-resistive applications as well. Surfaces with predetermined arrays of atomic scale features may also be of value in making patterned substrates for biological sensors. The primary project goal is to more fully understand the fundamental processes involved in Si morphology control and to explore the extension and application of these processes to other materials. Specific objectives of the project include: 1)Study of the temperature and growth rate conditions to create atomically flat mesa structures on Si(001) and Si(111) by vapor deposition plus related work on the use of chemical etching as an alternative to sublimation. 2)Study of the types of point defects existing at high temperatures through AFM and STM observations on quenched Si surfaces with extremely large terraces. 3)Develop ways to make potentially useful patterns of steps on Si and other substrates as templates for adsorbed or deposited structures. Applications will be sought with bio-molecules and with magnetic layers. 4)Study of the kinetics of oxide growth on atomically flat Si using an X-ray technique to monitor the intensity of forbidden reflections-analogous to RHEED oscillations. %%% The project addresses basic research issues in a topical area of materials science with high technological relevance. 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. The project assists development of technical, communication, and organizational/management skills in students through unique educational experiences made possible by a forefront highly collaborative research environment. Key collaborators in this project include Cornell-based researchers Dr. C.C. Umbach (Materials Science & Eng.), Prof. J. Engstrom (Chem. Eng.), Dr R. Headrick (CHESS), Prof M. Hines (Chemistry), Dr R. Tromp (IBM), and Dr N. Bartelt (Sandia). ***