Shape and surface morphology changes during the initial stages of encapsulation of InAs/GaAs quantum dots

被引：79

作者：

Joyce, PB ^{[1
]}

Krzyzewski, TJ ^{[1
]}

Steans, PH ^{[1
]}

Bell, GR ^{[1
]}

Neave, JH ^{[1
]}

Jones, TS ^{[1
]}

机构：

[1] Univ London Imperial Coll Sci Technol & Med, Dept Chem, Ctr Elect Mat & Devices, London SW7 2AY, England

来源：

SURFACE SCIENCE | 2001年 / 492卷 / 03期

基金：

英国工程与自然科学研究理事会;

关键词：

single crystal epitaxy; indium arsenide; gallium arsenide; quantum effects;

D O I：

10.1016/S0039-6028(01)01479-0

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The change in shape and surface morphology of InAs/GaAs(0 0 1) quantum dots (QDs) during their initial encapsulation by GaAs has been studied using reflection high energy electron diffraction (RHEED) and scanning tunnelling microscopy (STM). The shape of the QDs changes significantly during the earliest stages of overgrowth. In situ RHEED measurements show a significant chevron angle change after deposition of only 2 ML of GaAs, before losing all crystallographic structure as more GaAs is deposited. STM results indicate significant surface mass transport, the height of the QDs decreases faster than the rate at which the GaAs capping layer is deposited and the QDs effectively "collapse" during the earliest stages of encapsulation. The area of the partially capped QDs increases significantly with increasing GaAs deposition and there is an anistropic increase in shape with significant elongation along the [1 1 0] azimuth. (C) 2001 Elsevier Science B.V. All rights reserved.

引用

页码：345 / 353

页数：9

共 31 条

[1] Surface alloying at InAs-GaAs interfaces grown on (001) surfaces by molecular beam epitaxy [J].