Resonant Raman Scattering and Atomic Force Microscopy of InGaAs/GaAs Multilayer Nanostructures with Quantum Dots

Journal Article · Sat Jan 01 04:00:00 EST 2005 · Semiconductors

DOI:https://doi.org/10.1134/1.1852661· OSTI ID:20658150

Valakh, M Ya; Strelchuk, V V; Kolomys, A F ^[1]; Mazur, Yu I; Wang, Z M; Xiao, M; Salamo, G J ^[2]

---

1. Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, Kiev, 03028 (Ukraine)
2. University of Arkansas, Department of Physics, 72701 Arkansas (United States)

The transition from two-dimensional (2D) pseudomorphic growth to the three-dimensional (3D) (nanoisland) growth in In{sub x}Ga{sub 1-} {sub x}As/GaAs multilayer structures grown by molecular-beam epitaxy was investigated by atomic force microscopy, photoluminescence, and Raman scattering. The nominal In content x in In{sub x}Ga{sub 1-x}As was varied from 0.20 to 0.50. The thicknesses of the deposited In{sub x}Ga{sub 1-x}As and GaAs layers were 14 and 70 monolayers, respectively. It is shown that, at these thicknesses, the 2D-3D transition occurs at x {>=} 0.27. It is ascertained that the formation of quantum dots (nanoislands) does not follow the classical Stranski-Krastanov mechanism but is significantly modified by the processes of vertical segregation of In atoms and interdiffusion of Ga atoms. As a result, the In{sub x}Ga{sub 1-x}As layer can be modeled by a 2D layer with a low In content (x < 0.20), which undergoes a transition into a thin layer containing nanoislands enriched with In (x > 0.60). For multilayer In{sub x}Ga{sub 1-x}As structures, lateral alignment of quantum dots into chains oriented along the [1-bar10] direction can be implemented and the homogeneity of the sizes of quantum dots can be improved.

• OSTI ID: 20658150
• Journal Information: Semiconductors, Journal Name: Semiconductors Journal Issue: 1 Vol. 39; ISSN SMICES; ISSN 1063-7826
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ATOMIC FORCE MICROSCOPY
GALLIUM ARSENIDES
INDIUM COMPOUNDS
LAYERS
MOLECULAR BEAM EPITAXY
PHOTOLUMINESCENCE
QUANTUM DOTS
RAMAN EFFECT
RAMAN SPECTRA
SEGREGATION
SEMICONDUCTOR MATERIALS
THICKNESS