量子点外延生长新模型(英文)  

Novel Scenario for Epitaxial Growth Process of Quantum Dots

作　　者：吴巨[1] 

机构地区：[1]中国科学院半导体研究所半导体材料重点实验室,北京100083

出　　处：《微纳电子技术》2012年第3期141-146,共6页Micronanoelectronic Technology

基　　金：National Natural Science Foundation of China(60876086,60976057,60990315)

摘　　要：目前在原子尺度上人们对量子点分子束外延生长过程了解很少,所有关于量子点外延生长的理论模型和计算机模拟都是建立在传统的外延生长理论框架内。在传统理论框架内,量子点的生长过程被理解为发生在生长表面上一系列的单一的原子事件,如原子沉积、扩散、聚集等。在这种理论中,外延生长表面原子之间的相互作用被忽略;另外,按照这种理论,量子点生长过程必须是一个相对缓慢的过程。这种理论模型不可能恰当地解释所观察到的大量复杂的量子点外延生长实验现象。作者在两个实验现象基础上,提出了在InAs/GaAs(001)体系中量子点外延生长过程的新模型。这两个实验现象分别是在InAs/GaAs(001)生长表面有大量的"浮游"In原子,一个量子点的生长过程可以在很短的时间内完成(<10-4 s)。在提出的新模型中,量子点的自组装过程是一个大数量原子的集体、协调运动过程。At the present time, the self-assmbly of a quantum dot in a heteroepitaxy is generally understood in terms of the conventioal theoretical framework, in which the formation of a quantum dot during heteroepitaxy is implemented by a series of individual atomistic events, such as deposition, diffusion and attachment/detachment, occuring on the growing surface. According to this theoretical framework, the possible interactions among the adatoms on the growing surface are neglected, and, in addition, the self-assembly of a quantum dot has to be a relative timelengthy process. Obviously, the traditional theroy cannot provide a plausible explanation for the variety of experimental observations on the epitaxial growth of quantum dots. Inspirited by two experimental evidences in the literature and of their own, respectively： the presence of floa-ting indium on the growing surface in MBE InAs/GaAs （001） and that a quantum dot can form within a very short transient time （〈10^-4 S） under a given growth condition, the author put forward a novel scenario for the self-assembly process of quantum dots in the MBE InAs/GaAs （001）, in which the self-assembing of a quantum dot is a collective or coordinated event, involving a large number of atoms simultaneously.

关 键 词：InAs/GaAs(001) 量子点 自组装 原子集体运动 外延生长 

分 类 号：O471.1[理学—半导体物理]