Spatial point analysis of quantum dot nucleation sites on InAs wetting layer

SURFACE SCIENCE

卷:605

Article

Konishi, Tomoya¹  Tsukamoto, Shiro¹ 

[1] Anan Natl Coll Technol, Tokushima 7740017, Japan

关键词: Semiconductor;    MBE;    STM;    Wetting layer;    Quantum dot;    Nucleation;    Spatial point analysis;    Nearest-neighbor distance;   

DOI  :  10.1016/j.susc.2010.12.034

来源: Elsevier

【 摘 要 】

We perform spatial point analysis of InAs quantum dot (QD) nucleation sites and surface reconstruction domain patterns on an InAs wetting layer to investigate QD nucleation mechanisms in Stranski-Krastanow growth mode. An InAs wetting layer on a GaAs(001) substrate has been observed at 300 degrees C by using in situ scanning tunneling microscopy (STM) preceding QD formation. A nearest-neighbor analysis of the STM images finds that the point pattern of QD precursors is similar to that of (1 x 3)/(2 x 3) surface reconstruction domains which are specific to Ga-rich fluctuation. This provides the evidence that InAs QD nucleation is induced by Ga-rich fluctuation within an InAs wetting layer, as a technical implication for site-controlled QD growth for various QD devices. (C) 2011 Elsevier B.V. All rights reserved.

【 授权许可】

Free