Tailoring Surface Morphology of Epitaxial Layers on Silicon

定制硅外延层的表面形貌

• 批准号: 9528513
• 负责人: Ignatius Tsong
• 金额: $ 34.95万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-01-01 至 2001-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9528513&HistoricalAwards=false
• 关键词: Tailoring; Surface; Morphology; Epitaxial; Layers

9528513 Tsong This research project uses a unique combination of ultrahigh vacuum (UHV) microscopies: low energy electron microscopy (LEEM) and scanning tunneling microscopy (STM), to conduct in situ deposition and growth studies on Si surfaces to clearly identify different growth modes, i.e. Frank-van der Merwe, Volmer-Weber, and Stranski-Krastanov, and also to observe gross changes of the surface during growth, such as faceting and step-bunching. The investigation focuses on tailoring the surface morphology of homoepitaxial and heteroepitaxial layers on Si surfaces with different orientations. Ge/Si(100) and Ge/Si(311) and the homoepitaxial systems of Si/Si(100) and Si/Si(311) will be studied. Real-time LEEM observations of the development of 2D-island density during growth with and without a surfactant will be used to assess whether or not the presence of surfactants increases or reduces the diffusion lengths of adatoms to promote layer-by-layer growth. %%% The proposed LEEM/STM investigations are expected to pinpoint the role of energetics versus kinetics played by the high-index (311) substrate surface. STM, with its better spatial resolution, is ideal for the study of the initial stages of nucleation; while LEEM is particularly suited to examine growth kinetics dependent upon substrate temperature, diffusion rates and mass transport. These two powerful lateral spatial resolving techniques will enable identification of critical parameters necessary to tailor growth morphologies, and hence the synthesis of new and improved materials for microelectronic applications. The Ge/Si system is significant from the technological point of view of enhanced carrier mobility in SiGe/Si superlattices and their application in heterojunction bipolar transistors, while Si/Si homoepitaxy is a model system to study fundamental mechanisms controlling growth kinetics, in particular the minimization of substrate temperature for step-flow growth. The knowledge and understanding gained from this research pr oject is expected to contribute in a general way to improving the performance of advanced devices used in computing, information processing, and telecommunications by providing a fundamental understanding and a basis for designing and producing improved materials. 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. ***

9528513 Tsong该研究项目使用了一种独特的超真空（UHV）显微镜组合：低能电子显微镜（LEEM）和扫描隧道显微镜（STM），在Si表面上进行原位沉积和生长研究，以清楚地识别不同的生长模式，即Frank-van der Merwe、Volmer-Weber和Sttranski-Krastanov，并且还观察生长期间表面的总体变化，例如刻面和阶梯聚束。 研究的重点是在不同取向的Si表面上定制同质外延层和异质外延层的表面形貌。 Ge/Si（100）和Ge/Si（311）以及Si/Si（100）和Si/Si（311）的同质外延系统。 实时LEEM观察的发展过程中的二维岛密度的增长与没有表面活性剂将被用来评估是否存在的表面活性剂增加或减少的扩散长度的吸附原子，以促进逐层生长。拟议的LEEM/STM研究预计将精确定位高折射率（311）衬底表面所起的能量学与动力学的作用。 STM，具有更好的空间分辨率，是理想的成核的初始阶段的研究，而LEEM是特别适合于检查依赖于衬底温度，扩散速率和质量传输的生长动力学。 这两个强大的横向空间分辨技术将使识别的关键参数所需的定制生长形态，因此合成新的和改进的材料的微电子应用。Ge/Si系统从SiGe/Si超晶格中增强的载流子迁移率及其在异质结双极晶体管中的应用的技术观点来看是重要的，而Si/Si同质外延是研究控制生长动力学的基本机制的模型系统，特别是最小化阶梯流动生长的衬底温度。 从这项研究项目中获得的知识和理解，预计将有助于在一般的方式，以提高在计算，信息处理和电信中使用的先进设备的性能，通过提供一个基本的理解和基础，设计和生产改进的材料。 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。***