Stress Effects on Kinetic Processes

本项目涉及非静水应力对外延晶体生长和扩散动力学过程的影响的实验和理论研究相结合的方法。研究了应力激活、晶体生长势垒高度和表面扩散对晶体生长形态演变的影响。我们将测量简单、均匀的应力状态对平行和垂直于表面的薄膜中原子扩散的影响。非静水应力状态下的扩散理论将得到进一步发展。这项研究有望建立一种方法，通过测量动力学过程在几种简单的、均匀的应力状态下的应力相关性，可以预测任意的、非均匀的应力状态的影响--这被认为对未来的半导体器件的设计很重要。它还允许根据原子论理论计算和对外加应力的响应的实验观察的结果，确定在固体内部进行的、不能直接观察到的过程。预计这一努力的成功将促进新的、有趣的和潜在有用的材料的创建。该项目涉及具有很强技术相关性的电子材料科学领域的基础研究问题。该项目的一个重要特点是高度重视教育，并将研究与教育相结合。该研究计划提供了在使用尖端科学设备方面的实践经验的绝佳机会。现有资源为从事跨学科前沿材料科学研究的学生提供了特殊的教育和培训机会。***

This project involves a combined experimental and theoretical study of the effects of nonhy-drostatic stress on the kinetic processes of epitaxial crystal growth and diffusion. The impact of stress-dependent activation barrier heights for crystal growth and surface diffusion on growth morphology evolution will be studied. The effect of simple, uniform stress states on atomic dif-fusion in thin films, both parallel and perpendicular to the surface, will be measured. The theory of diffusion under nonhydrostatic stress states will be further developed. This research is ex-pected to establish methods by which the measurement of the stress-dependence of a kinetic pro-cess under a few simple, uniform stress states permits the prediction of the effect of an arbitrary, nonuniform stress state-deemed important for the design of future semiconductor devices. It also permits the determination of processes going on in the interior of solids, where they cannot be observed directly, from the results of atomistic theoretical calculations and experimental ob-servations of the response to imposed external stresses. It is anticipated that success in this en-deavor will facilitate the creation of new, interesting, and potentially useful materials. The project addresses fundamental research issues in areas of electronic materials science having strong technological relevance. An important feature of the project is the strong emphasis on education, and the integration of research and education. The research program provides excel-lent opportunities for hands-on experience in the use of sophisticated scientific equipment. The resources available provide special opportunities for education and training of students involved in interdisciplinary forefront materials science research. ***