Control of Microtopography at Silicon Surfaces and Interfaces

本计画针对矽及其他半导体表面缺陷的特性，并探讨在原子层级控制表面与界面形貌的方法。该研究涉及表面原子扩散的研究，表面原子步骤的能量学和动力学，氧化诱导的应变和表面和界面形态的详细控制。扫描隧道显微镜和低能电子显微镜被用来观察原子的步进运动和整个表面形状的演变之间的联系。 结果预计将是感兴趣的基础表面科学和先进的半导体器件和电路的制造。该研究可能有助于异质磁系统中的界面的设计和控制，如用于磁阻应用以及。具有原子尺度特征的预定阵列的表面在制造用于生物传感器的图案化衬底中也可能是有价值的。该项目的主要目标是更全面地了解Si形态控制所涉及的基本过程，并探索这些过程在其他材料中的扩展和应用。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）上创建原子级平坦梅萨结构的温度和生长速率条件，以及使用化学蚀刻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对淬态硅表面大台阶的高温点缺陷类型的研究。3)开发方法，使潜在的有用的模式的步骤上硅和其他基板作为模板的吸附或沉积结构。应用将寻求与生物分子和磁性层。4)用X射线技术监测禁戒反射强度--类似于RHEED振荡--研究原子级平面硅上氧化物生长的动力学。该项目解决了材料科学领域的基础研究问题，具有高度的技术相关性。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。该项目通过独特的教育经验，通过前沿的高度协作的研究环境，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.博士。Umbach（材料科学工程师），J. Engstrom教授（化学工程），R博士Headrick（国际象棋），M. Hines（化学），Dr R. Tromp（IBM）和N.巴特尔特（桑迪亚）。 ***

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). ***