Molecular Beam Epitaxy of PbTe/EuTe Superlattices

1992 ◽  
Vol 281 ◽  
Author(s):  
G. Springholz ◽  
G. Bauer
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Growth Conditions ◽  
High Energy ◽  
Small Range ◽  
Layer By Layer ◽  
Optimum Conditions ◽  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
Surface Reconstructions

ABSTRACTUsing reflection high energy electron diffraction (RHEED), the heteroepitaxy of EuTe on PbTe (111) by molecular beam epitaxy (MBE) was investigated. The resulting EuTe (111) surfaces exhibit different surface reconstructions corresponding to a Te-stabilized or a Eu-stabilized surface. We have observed perfect 2D layer-by-layer heteroepitaxial growth and RHEED intensity oscillations only for a small range of growth conditions. Using such optimum conditions, we have fabricated strained PbTe/EuTe superlattices with superior structural perfection, as shown by high resolution x-ray diffraction.

A Study on the Growth of Cubic GaN Films Using an AlGaAs Buffer Layer Grown on GaAs (100) by Plasma-Assisted Molecular Beam Epitaxy

2000 ◽  
Vol 639 ◽  
Author(s):  
Ryuhei Kimura ◽  
Kiyoshi Takahashi ◽  
H. T. Grahn
Keyword(s):  
Molecular Beam Epitaxy ◽  
Buffer Layer ◽  
Molecular Beam ◽  
High Energy ◽  
Rf Plasma ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cubic Gan

ABSTRACTAn investigation of the growth mechanism for RF-plasma assisted molecular beam epitaxy of cubic GaN films using a nitrided AlGaAs buffer layer was carried out by in-situ reflection high energy electron diffraction (RHEED) and high resolution X-ray diffraction (HRXRD). It was found that hexagonal GaN nuclei grow on (1, 1, 1) facets during nitridation of the AlGaAs buffer layer, but a highly pure, cubic-phase GaN epilayer was grown on the nitrided AlGaAs buffer layer.

Bi-Based Superconducting Multilayers Obtained by Molecular Beam Epitaxy

1999 ◽  
Vol 13 (09n10) ◽  
pp. 991-996
Author(s):  
M. Salvato ◽  
C. Attanasio ◽  
G. Carbone ◽  
T. Di Luccio ◽  
S. L. Prischepa ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Xrd Analysis ◽  
High Energy ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Diffraction Model ◽  
Different Thickness

High temperature superconducting multilayers have been obtained depositing Bi2Sr2CuO6+δ(2201) and ACuO2 layers, where A is Ca or Sr, by Molecular Beam Epitaxy (MBE) on MgO and SrTiO3 substrates. The samples, formed by a sequence of 2201/ACuO2 bilayers, have different thickness of ACuO2 layers while the thickness of the 2201 layers is kept constant. The surface structure of each layer has been monitored by in situ Reflection High Energy Electron Diffraction (RHEED) analysis which has confirmed a 2D nucleation growth. X-ray diffraction (XRD) analysis has been used to confirm that the layered structure has been obtained. Moreover, one-dimensional X-ray kinematic diffraction model has been developed to interpret the experimental data and to estimate the period of the multilayers. Resistive measurements have shown that the electrical properties of the samples strongly depend on the thickness of the ACuO2 layers.

Molecular Beam Epitaxy Growth and Structural Characterization of Si/GaAs Superlattices

1992 ◽  
Vol 263 ◽  
Author(s):  
R.J. Matyi ◽  
H.J. Gillespie ◽  
G.E. Crook ◽  
J.K. Wade
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
High Energy ◽  
Structural Quality ◽  
Molecular Beam Epitaxy Growth ◽  
X Ray Diffraction ◽  
Superlattice Structure ◽  
Dynamical Simulation ◽  
Diffraction Patterns ◽  
High Level

ABSTRACTThe growth of high quality Si/GaAs superlattices on GaAs substrates using molecular beam epitaxy is described. A typical superlattice structure consisted of ten periods of thin (<5Å) layers of pseudomorphic silicon alternating with thick GaAs layers; typical GaAs thicknesses range from 100Å to 1850Å. In situ reflection high energy electron diffraction analysis of the structures during growth showed the silicon layers developed a (3 ×1) reconstruction, while the GaAs exhibited a (4×2)→(3×2)→(3×1)→(2×4) reconstruction sequence. Both observations agree with prior studies of the growth of embedded silicon in GaAs/Si/GaAs heterostructures. X-ray diffraction using the (004) reflection showed sharp and intense satellite peaks (out to 22 orders in one case), indicating a high level of structural quality. Very good agreement has been obtained between observed diffraction patterns and those calculated via dynamical simulation.

scholarly journals Strain Effects on Optical Properties of (In,Ga)As-Capped InAs Quantum Dots Grown by Molecular Beam Epitaxy on GaAs (113)A Substrate

2011 ◽  
Vol 2011 ◽  
pp. 1-5
Author(s):  
Faouzi Saidi ◽  
Mouna Bennour ◽  
Lotfi Bouzaïene ◽  
Larbi Sfaxi ◽  
Hassen Maaref
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Growth Conditions ◽  
High Energy ◽  
Biaxial Strain ◽  
High Energy Electron ◽  
Inas Quantum Dots ◽  
Small Quantum

We have investigated the optical properties of InAs/GaAs (113)A quantum dots grown by molecular beam epitaxy (MBE) capped by (In,Ga)As. Reflection high-energy electron diffraction (RHEED) is used to investigate the formation process of InAs quantum dots (QDs). A broadening of the PL emission due to size distribution of the dots, when InAs dots are capped by GaAs, was observed. A separation between large and small quantum dots, when they are encapsulated by InGaAs, was shown due to hydrostatic and biaxial strain action on large and small dots grown under specifically growth conditions. The PL polarization measurements have shown that the small dots require an elongated form, but the large dots present a quasi-isotropic behavior.

Growth of Nonpolar (1100) Films and Heterostructures by Plasma-Assisted Molecular Beam Epitaxy

2004 ◽  
Vol 831 ◽  
Author(s):  
Oliver Brandt ◽  
Yue Jun Sun ◽  
Klaus H. Ploog
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Surface Segregation ◽  
Multiple Quantum Well ◽  
Growth Conditions ◽  
High Energy ◽  
Growth Direction ◽  
Desorption Kinetics ◽  
Multiple Quantum ◽  
Kinetics Of

ABSTRACTWe discuss the growth of M-plane GaN films and (In, Ga)N/GaN multiple quantum well (MQW) structures on LiAlO2(100) substrates by plasma-assisted molecular beam epitaxy. The adsorption and desorption kinetics of Ga on M-plane GaN is studied by reflection high-energy electron diffraction, allowing us to identify the optimum growth conditions with regard to surface morphology. Furthermore, we investigate the compositional profile of M-plane (In, Ga)N/GaN MQWs grown under conditions resulting in comparatively abrupt interfaces. The results demonstrate that significant In surface segregation occurs for the case of M-plane (In, Ga)N. The dependence of the transition energies of the M-plane MQWs on the actual well thickness reveals, however, that the structures are indeed free of electrostatic fields along the growth direction.

Characterization of Al/GaAs Schottky barriers with thin Si interfacial layers

1993 ◽  
Vol 51 ◽  
pp. 800-801
Author(s):  
M.W. Bench ◽  
T.J. Miller ◽  
M.I. Nathan ◽  
C.B. Carter
Keyword(s):  
Molecular Beam Epitaxy ◽  
Barrier Height ◽  
Molecular Beam ◽  
Schottky Diodes ◽  
Growth Conditions ◽  
High Energy ◽  
Exact Nature ◽  
Interfacial Layers ◽  
Transmission Electron ◽  
Layer Structures

It has been shown in previous reports that barrier height variations can be achieved in GaAs Schottky diodes grown using molecular beam epitaxy by utilizing a thin epitaxial Si layer (a few monolayers) between the GaAs and the Al contact. The effective barrier height was found to be dependent on the thickness and growth conditions of the Si layer. However, there has remained a question as to the exact nature of the interfacial Si layer. In the present investigation, samples with different Si layer thicknesses (no Si, 6 Å Si, and 20 Å Si, as determined in situ during growth using reflection high energy electron diffraction (RHEED)) were characterized using transmission electron microscopy (TEM) to determine the nature of the Si layers. In the present study, it was also found that the presence of the interfacial Si layers affected the growth orientation and morphology of the Al layers.The layer structures investigated were grown using molecular beam epitaxy in a system described elsewhere.

Drastic Change in the Gan Film Quality by In-Situ Controlling Surface Reconstructions In Gsmbe

1997 ◽  
Vol 482 ◽  
Author(s):  
X. Q. Shen ◽  
S. Tanaka ◽  
S. Iwai ◽  
Y. Aoyagi
Keyword(s):  
Growth Conditions ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Gas Source ◽  
Atomic Force ◽  
Surface Reconstructions ◽  
Gan Film

AbstractGaN growth was performed on 6H-SiC (0001) substrates by gas-source molecular beam epitaxy (GSMBE), using ammonia (NH3) as a nitrogen source. Two kinds of reflection high-energy electron diffraction (RHEED) patterns, named (1×1) and (2×2), were observed during the GaN growth depending on the growth conditions. By careful RHEED study, it was verified that the (1×1) pattern was corresponded to a H2-related nitrogen-rich surface, while (2×2) pattern was resulted from a Ga-rich surface. By x-ray diffraction (XRD), photoluminescence (PL) and atomic force microscopy (AFM) characterizations, it was found that the GaN quality changed drastically grown under different RHEED patterns. GaN film grown under the (1×1) RHEED pattern showed much better qualities than that grown under the (2×2) one.

Fabrication and characterization of ZnMgO nanowalls grown on 4H-SiC by molecular beam epitaxy

2019 ◽  
Vol 52 (1) ◽  
pp. 168-170
Author(s):  
Mieczyslaw A. Pietrzyk ◽  
Aleksandra Wierzbicka ◽  
Marcin Stachowicz ◽  
Dawid Jarosz ◽  
Adrian Kozanecki
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Optoelectronic Devices ◽  
Growth Conditions ◽  
Buffer Layers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fabrication And Characterization

Control of nanostructure growth is a prerequisite for the development of electronic and optoelectronic devices. This paper reports the growth conditions and structural properties of ZnMgO nanowalls grown on the Si face of 4H-SiC substrates by molecular beam epitaxy without catalysts and buffer layers. Images from scanning electron microscopy revealed that the ZnMgO nanowalls are arranged in parallel rows following the stripe morphology of the SiC surface, and their thickness is around 15 nm. The crystal quality of the structures was evaluated by X-ray diffraction measurements.

Epitaxial Growth and Characterization of NbxTi1−xO2 Rutile Films by Oxygen-Plasma-Assisted Molecular Beam Epitaxy

1995 ◽  
Vol 401 ◽  
Author(s):  
Y. Gao ◽  
S. A. Chambers
Keyword(s):  
Molecular Beam Epitaxy ◽  
Photoelectron Spectroscopy ◽  
Oxygen Plasma ◽  
Molecular Beam ◽  
High Energy ◽  
Epitaxial Films ◽  
Layer By Layer ◽  
Force Microscopy ◽  
Atomic Force

AbstractEpitaxial films of NbxTi1−xO2 rutile were grown on TiO2 (110) and (100) at 600 °C by oxygen-plasma-assisted molecular beam epitaxy using elemental Ti and Nb sources. The epitaxial films were characterized by means of reflection high-energy and low-energy electron diffraction (RHEED/LEED), x-ray photoelectron spectroscopy and diffraction (XPS/XPD), ultraviolet photoemission spectroscopy (UPS) and atomic force microscopy (AFM). The epitaxial films grow in a layer-by-layer fashion and have excellent short- and long-range structure order at x≤0.3 on TiO2(110) and at x≤0.15 on TiO2(100). However, the epitaxial films become rough and disorder at higher doping levels. Nb substitutionally incorporates at cation lattice sites, leading to NbxTi1−xO2 solid solutions. In addition, the oxidation state of Nb in the NbxTi1−xO2 films has been determined to be +4.

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