Ž . Applied Surface Science 166 2000 326–331 www.elsevier.nlrlocaterapsusc Strained InAs nanostructures self-organised on high-index ž / InP 113 B J. Brault ) , M. Gendry, G. Grenet, A. Solere, M. Phaner-Goutorbe, Y. Robach, ` L. Porte, G. Hollinger Ecole Centrale de Lyon, Laboratoire d’Electronique-LEOM, CNRS-UMR5512, 36 AÕ. Guy de Collongue, F-69131 Ecully, France Abstract Ž . Ž . We investigated self-assembled InAs islands grown on In Al AsrInP 113 B by molecular beam epitaxy MBE 0.52 0.48 Ž . Ž . using in-situ reflection high-energy electron diffraction RHEED and in-situ scanning tunnelling microscopy STM . For a Ž . deposition of 3 monolayers MLs of InAs, the STM topography revealed a high density of well-organised hexagonal Ž . w x facetted dots. The dots are truncated height ;3 nm and elongated along the 110 direction. Their typical base dimensions are approximately 48 and 19 nm. The angles between facet orientation and crystal direction were accurately deduced from RHEED patterns. From these structural characterisations, the dot shape and formation mechanism are discussed using a standard scheme based on surface energy minimisation. A direct correlation is found between the dot shape and the surface reconstruction unit cell. q 2000 Elsevier Science B.V. All rights reserved. Ž . Keywords: Strained InAs nanostructures; High-index InP 113 B; Molecular beam epitaxy 1. Introduction One of today’s challenges in material engineering is to produce well-confined quantum nanostructures that are usable in optoelectronic devices such as lasers or photodetectors. Much work has been done to grow, characterise, and study the formation of self-organised quantum nanostructures resulting from the Stranski–Krastanov growth mode of III–V semi- w x conductor strained layers 1–3 . Recently, high-index Ž . Ž . 113 A and 113 B surfaces have emerged as partic- ularly powerful tools to make well-organised wires w x and dots, respectively 4–7 . In this paper, we report ) Corresponding author. Tel.: q 33-47-2186086; fax: q 33-47- 8433593. Ž . E-mail address: julien.brault@ec-lyon.fr J. Brault . a study of the surface morphology of 3 monolayers Ž . MLs of InAs deposited by molecular beam epitaxy Ž . Ž . MBE on an InP 113 B-oriented surface using in-situ Ž . reflection high-energy electron diffraction RHEED Ž . and in-situ scanning tunnelling microscopy STM . Ž . These results suggest that as in the 113 A case, the Ž . 113 B surface reconstruction is responsible for the dot shape at least for the first steps of the dot formation. 2. Experimental The samples consist of 3 MLs of InAs deposited Ž . Ž by solid-source MBE on InP 113 B an epiready ˚ . substrate from InPact using a 4000-A In Al As 0.52 0.48 buffer. Growth was carried out in a Riber 2300 0169-4332r00r$ - see front matter q 2000 Elsevier Science B.V. All rights reserved. Ž . PII: S0169-4332 00 00474-8