Sub-Microsecond RHEED Investigation of Pulsed Laser Deposition Film Growth Dynamics

脉冲激光沉积薄膜生长动力学的亚微秒 RHEED 研究

• 批准号: 9903460
• 负责人: Jim Zheng
• 金额: $ 22.52万
• 依托单位: Florida Agricultural and Mechanical University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-01 至 2004-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9903460&HistoricalAwards=false
• 关键词: Sub; Microsecond; RHEED; Investigation; Pulsed

This project addresses surface processes during PLD(pulsed laser deposition)film formation. The approach incorporates a sub-microsecond time-resolved reflection high- energy electron diffraction (RHEED) analysis capability into a PLD system. A fast intensified CCD imaging system will be used to capture full- pattern RHEED images of the substrate to permit resolution of the laser ablation plume(10 to 100 us). The system is expected to provide a detailed picture of the changing surface structure of the film before, during and immediately after the arrival of the ablation plume ejected from the target, as well as during the relaxation time between laser pulses. The investigation will concentrate primarily on silicon homoepitaxy using (100) and (111) substrates. In order to examine details of multiple component depositions, silicon-germanium film growth will also be studied by sub-microsecond time-resolved RHEED, and the velocity distributions of both silicon and germanium will be measured by optical time-of-flight. The correlation of observed transient RHEED patterns and measured velocity distributions will be used to gain insight into film formation including the relaxation time of energetic species, nucleation behavior and the possible formation of short-lived metastable alloy structures.%%%The project addresses basic research issues in a topical area of materials science having potential technological relevance. The basic knowledge and understanding gained from the research is expected to contribute to improving the perform-ance of microelectronic devices and circuits by providing a fundamental understanding and a basis for designing and producing improved materials, and materials combinations. A variety of fundamental issues are to be addressed in these investigations. 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 is cited at an HBCU institution. ***

该项目解决PLD（脉冲激光沉积）薄膜形成过程中的表面处理。该方法将亚微秒时间分辨反射高能电子衍射（RHEED）分析能力纳入PLD系统。一个快速增强的CCD成像系统将被用来捕捉基板的全图案RHEED图像，以允许分辨率的激光烧蚀羽（10至100 us）。该系统预计将提供一个详细的图片之前，期间和之后立即从目标喷出的烧蚀羽流的到来，以及在激光脉冲之间的弛豫时间的薄膜的表面结构的变化。研究将主要集中在使用（100）和（111）衬底的硅同质外延。为了研究多组分沉积的细节，还将通过亚微秒时间分辨RHEED研究硅锗薄膜的生长，并通过光学飞行时间测量硅和锗的速度分布。观察到的瞬态RHEED图案和测量的速度分布的相关性将用于深入了解膜的形成，包括含能物质的弛豫时间、成核行为和可能形成的短寿命亚稳合金结构。该项目涉及具有潜在技术相关性的材料科学专题领域的基础研究问题。从研究中获得的基本知识和理解，预计将有助于提高微电子器件和电路的性能，通过提供一个基本的理解和基础，设计和生产改进的材料，材料组合。 在这些调查中将处理各种基本问题。 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培训学生来整合研究和教育;该项目被HBCU机构引用。 ***