Coherent X-ray Studies of Surface Growth and Patterning Processes

非技术描述：控制材料表面的生长和纳米尺度图案对能源、通信和信息技术的许多应用至关重要。然而，开发更有用的材料的一个主要障碍是在这种过程中难以测量表面结构的演变。这项研究通过使用非常强的x射线来测量生长和图案过程中表面的纳米级动力学来应对这一挑战。这些实验之所以成为可能，是因为使用了最新的x射线源，这些x射线源正在迅速发展，亮度越来越高。实验测量结果与理论预测和计算机模拟结果进行了比较，从而提高了人们的理解和预测能力。这些知识可以帮助科学家和工程师更好地控制材料的表面过程，提高他们的技术能力。此外，该项目在材料研究的这一非常重要和快速发展的部分培养研究生，本科生和高中生，导致未来的材料创新事业。技术描述：本研究正在开发x射线光子相关光谱学，作为一种强大的新方法来研究生长和离子束图像化过程中表面的纳米级动力学。考虑到技术？在将其应用于此类具有挑战性的问题的早期阶段，检查其功能范围是很重要的。因此，这个项目正在研究一组精心挑选的系统和行为。首先，它被用来仔细探索非晶膜生长过程中动力学粗化的基本过程，这是一个长期存在的兴趣和争议的问题。其次，在有机半导体薄膜的气相沉积和III-V型氮化物外延薄膜的等离子体辅助原子层外延生长的背景下，研究了该技术在研究外延生长过程中的适用性。最后，研究了半导体离子束纳米图的动力学，这是一个实验和理论之间异常密切的相互作用的问题。在所有情况下，正在进行连续体和原子模型的模拟，以将观察结果与潜在机制联系起来。参与的研究生、本科生和高中生有很好的机会在基础研究和应用领域工作。参与课程的学生将学习到广泛的特征和计算工具，这些工具可以很好地转化为未来在工业界或学术界的职业生涯。

Nontechnical description: Controlling the growth and nanometer-scale patterning of materials surfaces is critical to many applications in energy, communication and information technologies. However, a major impediment to developing more useful materials is the difficulty of measuring the evolution of surface structure during such processes. This research meets that challenge by using very intense x-rays to measure the nanometer-scale dynamics on surfaces during growth and patterning. These experiments are made possible by the use of the latest x-ray sources, which have been rapidly developing increasing brightness. The experimental measurements are compared with predictions of theory and computer simulations, leading to increased understanding and predictive power. Such knowledge can help scientists and engineers better control surface processes on materials, enhancing their technological capabilities. In addition, the project trains graduate, undergraduate and high school students in this very important and rapidly developing part of materials research, leading to future careers in materials innovation.Technical description: This research is developing x-ray photon correlation spectroscopy as a powerful new approach to investigating the nanoscale dynamics of surfaces during growth and ion beam patterning. Given the technique?s early stage of application to such challenging problems, it is important to examine the range of its capabilities. This project is therefore investigating a carefully chosen set of systems and behaviors. First, it is being used to carefully probe the fundamental processes in kinetic roughening during amorphous film growth, an issue of long-standing interest and controversy. Second, the applicability of the technique to investigating epitaxial growth processes is being examined within the context of vapor deposition of organic semiconductor films and plasma-assisted atomic layer epitaxial growth of III-V nitride epitaxial films. Finally, the dynamics of semiconductor ion beam nanopatterning, an issue generating unusually close interaction between experiment and theory, is being studied. In all cases, simulations of continuum and atomistic models are being performed to relate observations to underlying mechanisms. Graduate, undergraduate and high school students involved have an outstanding opportunity to work in an area that bridges basic research and application. Participating students learn a wide range of characterization and computational tools that can translate well to future careers in industry or academia.