Coherent X-ray Studies of Surface Growth and Patterning Processes

非技术性描述：控制材料表面的生长和纳米尺度图案化对于能源、通信和信息技术中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些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烈的x射线来测量生长和图案化过程中表面上的纳米级动态来应对这一挑战。 这些实验是通过使用最新的X射线源而实现的，这些X射线源一直在迅速发展，亮度不断增加。 实验测量与理论和计算机模拟的预测进行比较，从而提高理解和预测能力。 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，该项目还培养了研究生、本科生和高中生在材料研究这一非常重要且快速发展的领域的能力，从而使他们在材料创新领域拥有未来的职业生涯。技术描述：该研究正在开发X射线光子相关光谱，作为一种强大的新方法，用于研究生长和离子束图案化过程中表面的纳米级动力学。 鉴于技术？在应用于此类具有挑战性的问题的早期阶段，重要的是要检查其功能的范围。 因此，这个项目正在研究一套精心挑选的系统和行为。 首先，它被用来仔细探测的基本过程中的动力学粗糙化在非晶薄膜生长，长期的兴趣和争议的问题。 第二，该技术的适用性，调查外延生长过程中的有机半导体薄膜的气相沉积和III-V族氮化物外延膜的等离子体辅助原子层外延生长的背景下正在检查。最后，半导体离子束纳米图案化的动力学，实验和理论之间产生异常密切的相互作用的问题，正在研究中。 在所有情况下，正在进行连续统和原子模型的模拟，以将观测结果与基本机制联系起来。 研究生、本科生和高中生都有很好的机会在基础研究和应用领域工作。 参与的学生学习广泛的表征和计算工具，可以很好地转化为未来的职业生涯在工业或学术界。

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.