Spontaneous Formation of Identical Collections of Nanostructures During Semiconductor Heteroepitaxy

小行星9402184 将进行研究，以发展与直接外延沉积相关的工艺的基本理解，自发地形成一个相同的，无缺陷的纳米结构在Ge/Si（100）异质外延的集合。 原位（低能电子显微镜，扫描隧道显微镜和超真空扫描透射电子显微镜）和非原位（透射电子显微镜）显微镜的独特组合将用于评估这些纳米结构的尺寸，均匀性，面密度和空间分布。 通过改变沉积参数来改变生长表面上的移动的吸附原子（过饱和）的浓度，将研究调整点的均匀集合的尺寸。这些纳米结构的尺寸将通过Ge中的玻尔半径（约10 nm）进行调整，以研究量子限制的影响。 直接外延沉积的使用允许在半导体表面上原位地并且最重要地在单个步骤中形成目标结构。 该计划的主要目标是发展的外延生长，加工和Ge/Si量子点的属性的基本理解，使它们可以在各种先进的电子和光子器件的实现利用。 该计划的一个重要特点是在材料和加工研究的基本和技术重要领域培养研究生和本科生。 这项研究将有助于提高用于计算，信息处理和电信的先进器件和集成电路的一般性能。 ***

9402184 Drucker Research will be carried out to develop a fundamental understanding of the processes associated with direct epitaxial deposition to spontaneously form a collection of identical, defect free nanostructures during Ge/Si(100) heteroepitaxy. A unique combination of both in situ (low energy electron microscopy, scanning tunneling microscopy and ultrahigh vacuum scanning transmission electron microscopy) and ex situ (transmission electron microscopy) microscopy will be used to asses the size, uniformity, areal density and spatial distribution of these nanostructures. Tuning the size of uniform collections of dots will be investigated by varying the concentration of mobile adatoms (supersaturation) on the growth surface through changes in deposition parameters. The size of these nanostructures will be tuned through the Bohr radius in Ge, about 10 nm, to investigate the effects of quantum confinement. Use of direct epitaxial deposition allows formation of the target structures on a semiconductor surface, in situ and, most importantly, in a single step. %%% The primary goal of this program is to develop a fundamental-understanding of the epitaxial growth, processing, and properties of Ge/Si quantum dots so that they can be exploited in the realization of a variety of advanced electronic and photonic devices. An important feature of the program is the training of graduate and undergraduate students in a fundamentally and technologically significant area of materials and processing research. This research will contribute to improving the general performance of advanced devices and integrated circuits used in computing, information processing, and telecommunications. ***