Self-Organized Phases and Patterns in Epitaxial Film Systems

本理论研究解决了量子点和量子线的自组装形成问题。本研究将探讨几种制备参数对单组分基板上多组分固体薄膜的稳定性、生长和重构的影响。表面扩散和体扩散似乎是两种主要的机制。这项工作将从重新推导多相固体在应力作用下热化学反应的控制方程开始。其目的是重新捕捉到迄今为止被认为可以忽略不计的因素。更具体地说，该理论将重新检查化学势的完整性和普遍性，特别强调失配参数的作用。分析考虑将包括，但不限于，多组分固体的形态和组成的不稳定性，以及由非平版印刷方法产生的衬底图案的影响，例如埋藏错配位错网络或柔性衬底的周期性应变场，对自组织的影响。预计这项研究将对目前生产尺寸和分布均匀的纳米级半导体岛的努力产生重大影响。在传统晶体管和电路无法进一步小型化的情况下，这种自组织的小结构被认为是未来15到20年内新型电子设备的未来。通过这种方式，该项目将为另一项里程碑式技术的进步做出贡献，并为理解微米到纳米范围内的新现象做出贡献

0010077WuThis theoretical study addresses the formation of quantum dots and wires by self assembly. The study will address the effect of several fabrication parameters on the stability, growth and restructuring of thin multi-component solid films on single-component substrates. Surface and bulk diffusions appear to be two major mechanisms. The effort will begin with a re-derivation of the governing equations for thermochemical responses of multiphase solids under stress. The objective is to recapture the factors that have been heretofore thought to be negligible. More specifically, the theory will be reexamined for completeness and generality in chemical potential, with particular emphasis on the role of mismatch parameter. Analytical considerations will include, but not limited to, the morphological and compositional instabilities of multi-component solids, and the effect of substrate pattern generated by non-lithographic methods, such as the periodic strain field of a buried misfit dislocation network or a compliant substrate, on self-organization. The proposed investigation is expected to have a significant impact on the ongoing effort in producing nano-scale semiconductor islands of uniform size and distribution. Such self-organized small structures are thought to be the future of new electronic devices in just 15 or 20 years when conventional transistors and circuits can not be miniaturized further. In this way, the project will have contributed to the advance of another milestone technology, as well as to the understanding of a new phenomenon in the micron-to-nano range.***