Molecular Beam Epitaxial Growth of (Al,Ga)As Tilted Superlattices on Vicinal GaAs (110)

1991 ◽  
Vol 237 ◽  
Author(s):  
Mohan Krishnamurthy ◽  
M. Wassermeier ◽  
H. Weman ◽  
J. L. Merz ◽  
P. M. Petroffa
Keyword(s):  
Quantum Wells ◽  
Molecular Beam ◽  
Growth Conditions ◽  
Vicinal Surface ◽  
Vicinal Surfaces ◽  
Island Growth ◽  
Quantum Well Structures ◽  
Molecular Beam Epitaxial ◽  
Transmission Electron ◽  
Molecular Beam Epitaxial Growth

ABSTRACTA study of the molecular beam epitaxial (MBE) growth on singular and vicinal (110) surfaces of GaAs is presented. Quantum well structures and tilted superlattices (TSL) were grown on substrates misoriented 0.5°-2° towards the nearest [010] and [111]A azimuths at growth temperatures ranging from 450° C to 600° C under different growth conditions. The structures were characterized by Nomarski optical microscopy, transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy.Two types of faceting were observed on the surfaces. The structures grown at temperatures above 540°C and As beam fluxes below l×10-5 torr showed V-shaped facets pointing in the [001] direction and are attributed to As deficient island growth. Lower temperatures and higher As beam fluxes lead to surfaces with microfacets that are elongated along the respective step directions on the vicinal surface and are due to step bunching during growth. Their density and height decrease with decreasing vicinal angle and they disappear on the singular (110) surface. The photoluminescence of the GaAs quantum wells grown on these samples is redshifted with respect to that of the quantum wells grown on the flat surface. This is being ascribed to the fact that on the vicinal surface, the recombination takes place at the facets where the quantum wells are wider.The contrast in the TEM images of the TSL show for the samples misoriented towards [010] that the lateral segregation to the step edges on this surface is appreciable. The TSL spacing and the tilt however show that during growth the vicinal surfaces tend towards a surface with smaller miscut.

Molecular Beam Epitaxial Growth of InAs/AIGaAsSb Deep Quantum Wells on GaAs Substrates

1995 ◽  
Vol 399 ◽  
Author(s):  
N. Kuze ◽  
H. Goto ◽  
S. Miya ◽  
S. Muramatsu ◽  
M. Matsui ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Molecular Beam ◽  
High Energy ◽  
High Electron ◽  
Quantum Well Structures ◽  
Force Microscopy ◽  
Molecular Beam Epitaxial ◽  
Gaas Substrates ◽  
Initial Stage ◽  
Molecular Beam Epitaxial Growth

ABSTRACTWe have investigated InAs deep quantum well structures (InAs DQWs) made from InAs/A1GaAsSb materials on GaAs substrates by molecular beam epitaxy (MBE). In the InAs DQWs, AlGaAsSb layers are lattice-matched to InAs. Using reflection high-energy electron diffraction (RHEED) linescan image analysis, we show that AlGaAsSb on GaAs surfaces quickly relaxes within 3 to 7 monolayers (MLs). The initial stages of AlxGa1-xAsSb (0≤x≤0.5) growth on GaAs (100) substrates and InAs growth on AlGaAsSb layers have been investigated by atomic force microscopy. The ridgeline shapes of AlGaAsSb are observed at the initial stage on GaAs surfaces. In the interface of the InAs/AIGaAsSb, two-dimensional (2D) growth of InAs has been observed. With a thin buffer layer of 600 nm AlGaAsSb, we have achieved very high electron mobilities of more than 32000 cm2/V-s at room temperature.

Photoluminescence Studies of a Quantum Well Modulated by Faceting on Gaas (110) Surfaces

1993 ◽  
Vol 312 ◽  
Author(s):  
S. Tomiya ◽  
C. M. Reaves ◽  
M. Krishnamurthy ◽  
M. Wassermeier ◽  
D. Bimberg ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Epitaxial Growth ◽  
Molecular Beam ◽  
Interface Roughness ◽  
Vicinal Surface ◽  
Temperature Dependent ◽  
Molecular Beam Epitaxial ◽  
Photoluminescence Studies ◽  
Molecular Beam Epitaxial Growth

AbstractStep bunching during epitaxial growth results in the transformation of a vicinal surface into a periodic array of micro-facets. Molecular beam epitaxial growth on the vicinal GaAs (110) surface exhibits this phenomenon which has primarily been characterized by electron microscopy. GaAs quantum wells with AlAs barriers were grown on GaAs(110) substrates vicinal 0.5-2· towards [010]. The faceting on the vicinal surface creates two distinct quantum well thicknesses. While most of the quantum well is 96Å thick, it broadens at the faceted regions. This thickness modulation produces two distinct luminescence peaks. By using temperature dependent photoluminescence, we have observed trends in exciton mobility. The exciton mobility decreases at low temperatures for the 1.0° and 2.0° samples, indicating a scattering mechanism. We will discuss interface roughness and other sources of scattering.

Self-assembled quantum dots and nanoholes by molecular beam epitaxial growth and atomically precise in situ etching

2002 ◽  
Vol 722 ◽  
Author(s):  
S. Kiravittaya ◽  
R. Songmuang ◽  
O. G. Schmidt
Keyword(s):  
Quantum Dots ◽  
Molecular Beam ◽  
Flat Surface ◽  
Local Strain ◽  
Growth Conditions ◽  
Etching Depth ◽  
Molecular Beam Epitaxial ◽  
Self Assembled ◽  
Molecular Beam Epitaxial Growth

AbstractEnsembles of homogeneous self-assembled quantum dots (QDs) and nanoholes are fabricated using molecular beam epitaxy in combination with atomically precise in situ etching. Self-assembled InAs QDs with height fluctuations of ±5% were grown using a very low indium growth rate on GaAs (001) substrate. If these dots are capped with GaAs at low temperature, strong room temperature emission at 1.3 νm with a linewidth of 21 meV from the islands is observed. Subsequently, we fabricate homogeneous arrays of nanoholes by in situ etching the GaAs surface of the capped InAs QDs with AsBr3. The depths of the nanoholes can be tuned over a range of 1-6 nm depending on the nominal etching depth and the initial capping layer thickness. We appoint the formation of nanoholes to a pronounced selectivity of the AsBr3 to local strain fields. The holes can be filled with InAs again such that an atomically flat surface is recovered. QDs in the second layer preferentially form at those sites, where the holes were initially created. Growth conditions for the second InAs layer can be chosen in such a way that lateral QD molecules form on a flat surface.

Molecular beam epitaxial growth window for high-quality (Ga,In)(N,As) quantum wells for long wavelength emission

2006 ◽  
Vol 88 (19) ◽  
pp. 191115 ◽  
Author(s):  
Fumitaro Ishikawa ◽  
Michael Höricke ◽  
Uwe Jahn ◽  
Achim Trampert ◽  
Klaus H. Ploog
Keyword(s):  
Quantum Wells ◽  
Epitaxial Growth ◽  
Molecular Beam ◽  
High Quality ◽  
Long Wavelength ◽  
Molecular Beam Epitaxial ◽  
Wavelength Emission ◽  
Molecular Beam Epitaxial Growth

Spontaneous Lateral Modulations in InAlAs Buffer Layers Grown by MBE on InP Substrates

1995 ◽  
Vol 417 ◽  
Author(s):  
F. Peiró ◽  
A. Cornet ◽  
J. C. Ferrer ◽  
J. R. Morante ◽  
G. Halkias ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Molecular Beam ◽  
Buffer Layers ◽  
Single Quantum ◽  
X Ray Diffraction ◽  
Single Quantum Well ◽  
Quantum Well Structures ◽  
X Ray ◽  
Transmission Electron ◽  
Inp Substrates

AbstractTransmission Electron Microscopy (TEM) and X-ray Diffraction (XRD) have been used to analyze the spontaneous appearance of lateral composition modulations in InyAl1−yAs (yIn.≅ 50%) buffer layers of single quantum well structures grown by molecular beam epitaxy on exact and vicinal (100) InP substrates, at growth temperatures in the range of 530°C–580°C. The influence of the growth temperature, substrate misorientation and epilayer mismatch on the InAlAs lateral modulation is discussed. The development of a self-induced quantum-wire like morphology in the In0.53Ga0.47As single quantum wells grown over the modulated buffers is also commented on.

Ammonia-molecular-beam epitaxial growth and optical properties of GaN/AlGaN quantum wells

2002 ◽  
Vol 91 (12) ◽  
pp. 9685 ◽  
Author(s):  
H. Tang ◽  
J. B. Webb ◽  
P. Sikora ◽  
S. Raymond ◽  
J. A. Bardwell
Keyword(s):  
Optical Properties ◽  
Quantum Wells ◽  
Epitaxial Growth ◽  
Molecular Beam ◽  
Molecular Beam Epitaxial ◽  
Molecular Beam Epitaxial Growth
Sign in / Sign up

Export Citation Format

Share Document