TY - JOUR
T1 - Defect creation in InGaAs/GaAs multiple quantum wells-I. Structural properties
AU - Karow, Matthias M.
AU - Faleev, Nikolai N.
AU - Smith, David
AU - Honsberg, Christiana
N1 - Funding Information:
This material is based upon work primarily supported by the Engineering Research Center Program of the National Science Foundation and the Office of Energy Efficiency and Renewable Energy of the Department of Energy under NSF Cooperative Agreement No. EC‐1041895 . Any opinions, findings and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect those of NSF or DOE. We gratefully acknowledge the use of facilities within the LeRoy Eyring Center for Solid State Science at Arizona State University.
Publisher Copyright:
© 2015 Elsevier B.V. All rights reserved.
PY - 2015/7/28
Y1 - 2015/7/28
N2 - We present a systematic study of extended defect creation in InGaAs/GaAs multiple quantum well (MQW) structures. Three sets of samples, grown by molecular beam epitaxy, were characterized by high-resolution x-ray diffraction and transmission electron microscopy. First, in a temperature series, optimal deposition temperature of 505 °C was found for the In composition of 20% as determined from dislocation loop (DL) density and inspection of diffuse scattering patterns. InGaAs decomposition and lateral layer thickness undulations were observed above this optimal temperature. Second, increase of MQW periodicity from ×5 to ×10 revealed a thickness-related cumulative deterioration, characterized by increased likelihood of defect intersection with continued MQW growth, as suggested by an increase of the secondary DL density from ∼1.6×107 cm-2 to ∼6×108 cm-2. Additional strained layers experienced an ever-degrading quality of the growth surface. Third, a set consisting of samples with three different MQW periods was investigated. Different stages, suggested by a model of defect creation, were obtained for these different MQW periods, allowing specification of particular type, density, and spatial distribution of extended defects for each stage of defect creation.
AB - We present a systematic study of extended defect creation in InGaAs/GaAs multiple quantum well (MQW) structures. Three sets of samples, grown by molecular beam epitaxy, were characterized by high-resolution x-ray diffraction and transmission electron microscopy. First, in a temperature series, optimal deposition temperature of 505 °C was found for the In composition of 20% as determined from dislocation loop (DL) density and inspection of diffuse scattering patterns. InGaAs decomposition and lateral layer thickness undulations were observed above this optimal temperature. Second, increase of MQW periodicity from ×5 to ×10 revealed a thickness-related cumulative deterioration, characterized by increased likelihood of defect intersection with continued MQW growth, as suggested by an increase of the secondary DL density from ∼1.6×107 cm-2 to ∼6×108 cm-2. Additional strained layers experienced an ever-degrading quality of the growth surface. Third, a set consisting of samples with three different MQW periods was investigated. Different stages, suggested by a model of defect creation, were obtained for these different MQW periods, allowing specification of particular type, density, and spatial distribution of extended defects for each stage of defect creation.
KW - A1. Defects
KW - A1. High resolution x-ray diffraction
KW - A1. Nanostructures
KW - A3. Molecular beam epitaxy
KW - A3. Superlattices
KW - B2. Indium gallium arsenide
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U2 - 10.1016/j.jcrysgro.2015.03.051
DO - 10.1016/j.jcrysgro.2015.03.051
M3 - Article
AN - SCOPUS:84937852024
SN - 0022-0248
VL - 425
SP - 43
EP - 48
JO - Journal of Crystal Growth
JF - Journal of Crystal Growth
ER -