Surface processes during growth of InAs/GaAs quantum dot structures monitored by reflectance anisotropy spectroscopy

0342088 - FZÚ 2011 RIV NL eng J - Journal Article
Hospodková, Alice - Vyskočil, Jan - Pangrác, Jiří - Oswald, Jiří - Hulicius, Eduard - Kuldová, Karla
Surface processes during growth of InAs/GaAs quantum dot structures monitored by reflectance anisotropy spectroscopy.
Surface Science. Roč. 604, 3-4 (2010), 318-321. ISSN 0039-6028. E-ISSN 1879-2758
R&D Projects: GA AV ČR IAA100100719; GA ČR GA202/09/0676
Institutional research plan: CEZ:AV0Z10100521
Keywords : low-pressure Metal–Organic Vapor Phase * InAs/GaAs quantum dots * reflectance anisotropy spectroscopy Surface reconstruction * surface reconstruction
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 2.010, year: 2010

The time resolved reflectance anisotropy spectroscopy (RAS) measurement at 4.2 eV was used for the optimization of technological parameters for Stranski-Krastanow quantum dot (QD) formation. RAS measurement helps us to study the MOVPE surface processes such as QD formation, dissolution of In from InAs QDs during the growth of GaAs capping layer or recovery of epitaxial surface from As deficiency, when As partial pressure is increased. We have shown, that the recovery of epitaxial surface from As deficiency is rather a slow process of the order of tens of seconds. For the first time was observed in situ the mechanism of In atoms migration from QDs during GaAs capping layer growth. First the GaAs layer is formed and then the In migration from QDs follows. These two processes do not start at the same time, the In dissolution is delayed. Conclusions extracted from RAS measurement are in agreement with photoluminescence results.
Permanent Link: http://hdl.handle.net/11104/0184913