Understanding the growth mode transition in InAs/GaAs(0 0 1) quantum dot formation

• Published in: Surface science Vol. 532; pp. 822 - 827
• Main Authors: Krzyzewski, T.J., Joyce, P.B., Bell, G.R., Jones, T.S.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 10-06-2003
• Subjects: Gallium arsenide; Indium arsenide; Molecular beam epitaxy; Scanning tunneling microscopy; Surface structure, morphology, roughness, and topography; Molecular beam epitaxy; Scanning tunneling microscopy; Surface structure, morphology, roughness, and topography; Gallium arsenide; Indium arsenide
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/S0039-6028(03)00455-2

Scanning tunneling microscopy has been used to monitor the growth by molecular beam epitaxy of InAs quantum dots (QDs) on GaAs(0
0
1) at and near the critical coverage (
θ
crit). Direct evidence is obtained for the existence of small irregular 3D islands of height 6–12 Å (2–4 ML) which contain ∼150 atoms or more. These features develop rapidly (within 0.05 ML of
θ
crit) into regular mature QDs with an average volume >1
×
10
4 atoms. Scaling analysis of the QD size distributions suggests that strain may have a significant influence during QD nucleation and the initial stages of growth, but is unimportant during the later stages of QD development.