Low-temperature growth of self-assembled InAs dots on GaAs by molecular beam epitaxy

• Published in: Journal of crystal growth 2003-04, Vol.251 (1), p.135-139
• Main Authors: Zhan, H.H., Nötzel, R., Hamhuis, G.J., Eijkemans, T.J., Wolter, J.H.
• Format: Article
• Language: English
• Subjects: A2. Low temperature growth; A3. Molecular beam epitaxy; A3. Self-assembled InAs quantum dots; B1. GaAs; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Molecular, atomic, ion, and chemical beam epitaxy; Physics; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties)
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/S0022-0248(02)02469-7

We report low-temperature (LT) growth of self-assembled InAs dots on GaAs by molecular beam epitaxy. Atomic force microscopy reveals well-developed InAs dots grown at LT (250°C) on top of a LT GaAs bottom layer after post-growth annealing above 450°C. When the InAs dots are overgrown by LT GaAs, however, X-ray diffraction reveals poor structural quality of the dot- and the LT GaAs top layers. Excellent structural quality of the InAs dots and LT GaAs top layer is achieved when the dots, before LT GaAs overgrowth, are capped with a thin (3 nm) GaAs interlayer at 480°C and subsequently annealed at 580°C. Realization of these high-quality InAs dots grown at low substrate temperature may be useful for ultra-fast response optical devices.