Dynamical Processes of Epitaxial Growth

9618656科恩这个项目解决动态过程的外延生长。对于GaAs，表面形态的演变，岛的形成，交叉到阶梯流，以及吸附原子在生长动力学和形态中的作用将使用RHEED和STM研究。 一个重要的目标是利用所获得的知识来发展对薄膜生长的原子水平的理解和控制。 能量过滤RHEED将用于改善与动态计算的比较，并消除漫射强度测量中的不确定性。 在衍射的相关函数分析中将考虑阶跃边缘散射因子。该项目还将研究GaN在块状GaN片晶（晶须）上的生长;这种方法用于消除通常在蓝宝石上生长GaN时存在的非晶缓冲层的作用。其目的是获得明确的数据外延过程有直接关系的微观过程的增长。%该项目解决了具有高技术相关性的材料科学主题领域的前沿研究问题。 该研究将在基础层面上为电子/光子器件和集成电路的重要方面提供基础材料科学知识。 此外，从研究中获得的基本知识和理解预计将通过提供基本理解和设计和生产改进材料和材料组合的基础，以一般方式提高先进器件和电路的性能。 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。***

9618656 Cohen This project addresses dynamical processes of epitaxial growth. For GaAs, the evolution of surface morphology, island formation, crossover to step flow, and the role of adatoms in growth kinetics and morphology will be studied using RHEED and STM. An important goal is to use the knowledge obtained to develop atomic level understanding and control over film growth. Energy-filtered RHEED will be used to improve the comparison with dynamical calculations and to eliminate uncertainties in the measurement of diffuse intensities. Step edge scattering factors will be considered in the correlation function analysis of diffraction. The project will also study GaN growth on bulk GaN platelets(whiskers); this approach is used to remove the role of the amorphous buffer layer normally present with GaN growth on sapphire. The aim is to obtain definitive data on epitaxial processes having direct relationships to microscopic processes of growth. %%% The project addresses forefront research issues in a topical area of materials science having high technological relevance. The research will contribute basic materials science knowledge at a fundamental level to important aspects of electronic/photonic devices and integrated circuitry. Additionally, the fundamental knowledge and understanding gained from the research is expected to contribute in a general way to improving the performance of advanced devices and circuits by providing a fundamental understanding and a basis for designing and producing improved materials, and materials combinations. 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. ***