scholarly journals Спонтанное формирование кластеров In в эпитаксиальных слоях InN, выращенных методом молекулярно-пучковой эпитаксии

2018 ◽  
Vol 44 (4) ◽  
pp. 42
Author(s):  
Т.А. Комиссарова ◽  
В.Н. Жмерик ◽  
С.В. Иванов
Keyword(s):  
Molecular Beam ◽  
Indium Nitride ◽  
Growth Conditions ◽  
Nitrogen Plasma ◽  
Nitrogen Flow ◽  
Model Approximation ◽  
Mbe Growth ◽  
Flow Rates ◽  
Sapphire Substrates ◽  
The Magnetic Field

AbstractWe have studied the influence of growth conditions on the number of metallic indium clusters formed spontaneously in indium nitride (InN) layers grown by nitrogen plasma-assisted molecular-beam epitaxy (PAMBE). InN epilayers of N-and In-polarity were grown on c-sapphire substrates and GaN and AlN templates, respectively. N-polar layers were obtained in the standard PAMBE regime, while In-polar layers were grown using a three-stage regime including the stages of epitaxy with enhanced atomic migration and interruption of growth under nitrogen flow. A series of samples were prepared at various growth temperatures and relative In/N flow rates. Measurement of the magnetic-field dependences of the Hall-effect coefficient and its model approximation were used to determine the percentage content of In clusters in various InN layers and the minimum amount of such inclusions that can be achieved by varying the conditions of MBE growth.

Growth of Epitaxial IrSi3 Layers on Si(111)

1989 ◽  
Vol 160 ◽  
Author(s):  
T. L. Lin ◽  
C. W. Nieh
Keyword(s):  
Surface Morphology ◽  
Molecular Beam ◽  
Solid Phase ◽  
Single Mode ◽  
Growth Conditions ◽  
Tem Analysis ◽  
Mbe Growth ◽  
Good Surface ◽  
Transmission Electron

AbstractEpitaxial IrSi3 films have been grown on Si (111) by molecular beam epitaxy (MBE) at temperatures ranging from 630 to 800 °C and by solid phase epitaxy (SPE) at 500 °C. Good surface morphology was observed for IrSi3 layers grown by MBE at temperatures below 680 °C, and an increasing tendency to form islands is noted in samples grown at higher temperatures. Transmission electron microscopy (TEM) analysis reveals that the IrSi3 layers grow epitaxially on Si(111) with three epitaxial modes depending on the growth conditions. For IrSi3 layers grown by MBE at 630 °C, two epitaxial modes were observed with ~ 50% area coverage for each mode. Single mode epitaxial growth was achieved at a higher MBE growth temperature, but with island formation in the IrSi3 layer. A template technique was used with MBE to improve the IrSi3 surface morphology at higher growth temperatures. Furthermore, single-crystal IrSi3 was grown on Si(111) at 500 °C by SPE, with annealing performed in-situ in a TEM chamber.

scholarly journals Review of polarity determination and control of GaN

2004 ◽  
Vol 9 ◽  
Author(s):  
M. Sumiya ◽  
S. Fuke
Keyword(s):  
Molecular Beam ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Hydride Vapor Phase Epitaxy ◽  
Nitride Semiconductors ◽  
Sapphire Substrates ◽  
Polarity Determination ◽  
And Control ◽  
Systematic Control ◽  
Growth Methods

Polarity issues affecting III-V nitride semiconductors are reviewed with respect to their determination and control. A set of conditions crucial to the polarity control of GaN is provided for each of the following growth techniques; molecular beam epitaxy (MBE), pulsed laser deposition (PLD) and hydride vapor phase epitaxy (HVPE). Although GaN films might have been deposited by identical growth methods using the same buffer layer technologies, there is often a conflict between the resulting polarities achieved by different research groups. In this paper, we present the implications of the conditions used in each of the processes used for two-step metalorganic chemical vapor deposition (MOCVD), demonstrating systematic control of the polarity of GaN films on sapphire substrates. The potential for confusion in polarity control will be explained, taking into account the implications clarified in our studies. The correlation between the polarity and the growth conditions will be discussed in order to provide a mechanism for the determination and control of the crystal polarity during the growth of GaN films.

Non-Polar GaN/AlN Superlattices on A-plane AlN (500nm) Buffer Layers Grown by RF-MBE

2004 ◽  
Vol 831 ◽  
Author(s):  
Takayuki Morita ◽  
Akihiko Kikuchi ◽  
Katsumi Kishino
Keyword(s):  
Molecular Beam ◽  
Growth Conditions ◽  
Buffer Layers ◽  
Structural Quality ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sapphire Substrates ◽  
Frequency Plasma ◽  
Diffraction Peaks ◽  
Rich Side

ABSTRACTThe growth conditions of A-plane AlN and GaN epitaxial layers by radio-frequency plasma assisted molecular beam epitaxy on R-plane sapphire substrates were investigated. The growth temperature and V/III supply ratio dependency on structural quality and surface roughness was described. The optimum V/III ratio for A-plane GaN and AlN layers was shifted to nitrogen rich side compared to the C-plane layers. A-plane GaN/AlN superlattices (SLs) were also grown on R-plane sapphire substrates. The X-ray diffraction peaks from a primary and a 1st satellite were observed. From a comparison of low temperature photoluminescence peak wavelength between A-plane and C-plane SLs, the built-in electrostatic field originated from spontaneous and piezoelectric polarization is negligible for A-plane SLs.

MBE GROWTH OF GaAs NANOWHISKERS STIMULATED BY THE ADATOM DIFFUSION

2007 ◽  
Vol 06 (03n04) ◽  
pp. 225-231 ◽  
Author(s):  
V. G. DUBROVSKII ◽  
I. P. SOSHNIKOV ◽  
A. A. TONKIKH ◽  
V. M. USTINOV ◽  
G. E. CIRLIN ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Beam ◽  
Growth Conditions ◽  
Growth Mechanisms ◽  
Vapor Liquid Solid ◽  
Mbe Growth ◽  
Drop Radius ◽  
Adatom Diffusion ◽  
Vapor Liquid Solid Mechanism ◽  
Scanning Electron

The growth mechanisms of GaAs nanowhiskers (NWs) during molecular beam epitaxy (MBE) are studied theoretically and experimentally. A kinetic model of the diffusion-induced NW growth is presented that allows one to predict the dependence of NW length on the drop radius and on the technologically controlled MBE growth conditions. The results of scanning electron microscopy studies of GaAs NWs grown at different conditions on the GaAs (111) B surface activated by Au are presented and analyzed. It is shown that the length of NWs increases with decreasing the drop radius and with decreasing the deposition rate of GaAs , while its temperature dependence has a certain maximum. The aspect ratio of MBE-grown GaAs NWs is higher than 100. The maximum length of NWs is several times larger than the effective thickness of the deposited GaAs . The obtained results demonstrate that the NW growth is controlled by the adatom diffusion toward their tip rather than by the adsorption-induced vapor–liquid–solid mechanism. The growth conditions' influence on the NW morphology may be used for the controlled fabrication of NWs by MBE for different applications.

Structures of Nb/Al2O3 Interfaces Produced by Different Experimental Routes

1990 ◽  
Vol 183 ◽  
Author(s):  
J. Mayer ◽  
W. Mader ◽  
D. Knauss ◽  
F. Ernst ◽  
M. Rühle
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Molecular Beam ◽  
Al Alloy ◽  
Misfit Dislocations ◽  
Orientation Relationships ◽  
Cross Sectional ◽  
Mbe Growth ◽  
Sapphire Substrates ◽  
Transmission Electron

AbstractNb/Al2O3 interfaces were produced by (i) diffusion bonding of single crystalline Nb and Al2O3 at 1973 K, (ii) internal oxidation of a Nb-3at.% Al alloy at 1773 K, and (iii) molecular beam epitaxy (MBE) growth of 500 nm thick Nb overlayers on sapphire substrates at 1123 K. Cross-sectional specimens were prepared and studied by conventional (CTEM) and high resolution transmission electron microscopy (HREM). The orientation relationships between Nb and Al2O3 were identified by diffraction studies. HREM investigations revealed the structures of the different interfaces including the presence of misfit dislocations at or near the interface. The results for the different interfaces are compared.

Influence Of Growth Conditions On The Thermal Quenching Of Photoluminescence From Sige/Si Quantum Structures

1998 ◽  
Vol 533 ◽  
Author(s):  
I. A. Buyanova ◽  
W. M. Chen ◽  
W.-X. Ni ◽  
G. V. Hansson ◽  
B. Monemar
Keyword(s):  
High Temperature ◽  
Quantum Wells ◽  
Growth Temperature ◽  
Thermal Activation ◽  
Molecular Beam ◽  
Thermal Quenching ◽  
Growth Conditions ◽  
Mbe Growth ◽  
Temperature Growth ◽  
Optically Detected

AbstractIn this work we study effects of growth temperature and use of surfactant during growth on thermal quenching of photoluminescence (PL) from SiGe/Si quantum wells (QWs) grown by molecular beam epitaxy (MBE). We show that although all investigated structures demonstrate intense and sharp excitonic emissions from the SiGe QWs at liquid helium temperature, thermal quenching of this PL critically depends on the growth conditions. In particular, the use of low (⁤ 550°C) growth temperatures or employing Sb as a surfactant during high temperature (620°C) growth considerably degrades the PL thermal quenching behaviour by introducing some competing quenching processes with low activation energies of about 5 meV. The optimum growth conditions judging from the PL thermal behaviour are realised during high temperature growth without surfactant (620°C). Even higher growth temperature is shown to be required during surfactant mediated growth to improve the thermal quenching behaviour. From optically detected magnetic resonance (ODMR) studies, the competing quenching processes are attributed to a thermal activation of non-radiative defects introduced during either low-temperature MBE growth or during surfactant-mediated growth.

MBE Growth of InSb Based Device Structures onto InSb(111)A,(111)B and InGaSb(111)A Substrates

1996 ◽  
Vol 450 ◽  
Author(s):  
A D Johnson ◽  
R Jefferies ◽  
G J Pryce ◽  
J A Beswick ◽  
T Ashley ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Substrate Temperature ◽  
Molecular Beam ◽  
Growth Conditions ◽  
Optimum Growth ◽  
Mbe Growth ◽  
Light Emitting ◽  
Dopant Incorporation ◽  
Device Structures ◽  
Lattice Matched

ABSTRACTWe report on the optimum growth conditions for Molecular Beam Epitaxy (MBE) growth of InSb onto InSb (111)A and (111)B substrates. It was found that for (111)A substrates the optimum epilayer morphology was obtained for growth temperatures above 385°C and with a Sb:In ratio of 1.5:1. In contrast, for the (111)B surface, best morphology was found for growth temperatures above 385°C but with V:III ratio of ∼7.0:1. In both cases the dopant incorporation was found to be the same as the (100) surface and did not particularly depend either on V:III ratio or substrate temperature. We also describe the device characteristics of InAlSb light emitting diodes (LEDs) grown lattice matched onto ternary InGaSb(111)A substrates using the optimized growth conditions obtained.

Stoichiometry Related Phenomena in Low Temperature Grown GaAs

1993 ◽  
Vol 325 ◽  
Author(s):  
M. Missous ◽  
S. O'Hagan
Keyword(s):  
Low Temperatures ◽  
Molecular Beam ◽  
Growth Conditions ◽  
Time Data ◽  
High Quality ◽  
Mbe Growth ◽  
New Phenomena ◽  
First Time ◽  
Low Temperature Grown Gaas ◽  
Lt Gaas

AbstractThe growth of GaAs at low temperatures (LT-GaAs) at or below 250 °C, under standard Molecular Beam Epitaxy (MBE) growth conditions, usually results in a massive incorporation of excess As in the lattice which then totally dominates the electrical and optical characteristics of the as grown material. We report on new phenomena associated with the growth of GaAs at 250 °C and we show, for the first time, data on highly electrically active doped material. By careful control of the growth conditions, namely As4/Ga flux ratios, material in which total defect concentrations of less than 1017 cm-3, well below the huge 1020 cm-3 that is normally obtained in LT-GaAs, can be achieved thereby demonstrating that high quality GaAs can in effect be grown at extremely low temperatures.

Strained InGaAs/GaAs Multiple Quantum Wells Grown on Planar and Pre-Patterned GaAs(100) Substrates VIA Molecular Beam Epitaxy: Applications to Light Modulators and Detectors

1991 ◽  
Vol 228 ◽  
Author(s):  
Li Chen ◽  
Kezhong Hu ◽  
K. C. Rajkumar ◽  
S. Guhae ◽  
R. Kapre ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Molecular Beam ◽  
Contrast Ratio ◽  
Growth Conditions ◽  
Optical Quality ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Mbe Growth ◽  
Light Modulators ◽  
Transmission Electron

ABSTRACTWe report the realization of high quality strained InGaAs/GaAs multiple quantum wells (MQW) grown on planar GaAs (100) substrates through optimization of molecular beam epitaxical (MBE) growth conditions and structure. Such MQWs containing ∼ 11% In have lead to the realization of an asymmetric Fabry-Perot (ASFP) reflection modulator with a room temperature contrast ratio of 66:1 and an on-state reflectivity of 30%. For In composition ≥ 0.2, the improved optical quality for very thick (gt;2μm) InGaAs/GaAs MQWs grown on pre-patterned substrates is demonstrated via transmission electron microscopy (TEM) and micro-absorption measurements.

Dynamical calculations for RHEED from MBE growing surfaces. I. Growth on a low-index surface

1991 ◽  
Vol 432 (1885) ◽  
pp. 195-213 ◽  
Keyword(s):  
Electron Diffraction ◽  
Molecular Beam ◽  
Diffraction Theory ◽  
Growth Conditions ◽  
High Energy ◽  
Layer Growth ◽  
High Energy Electron ◽  
Mbe Growth ◽  
Diffusive Growth ◽  
Almost All

Dynamical diffraction calculations have been made for reflection high-energy electron diffraction (RHEED) from molecular beam epitaxy (MBE) growing surfaces. Effects due to both the diffraction and growth conditions on the RHEED intensity oscillations during MBE growth have been investigated in detail for perfect layer growth, non-diffusive, diffusive growth, and distributed growth on a low-index surface. The results are compared with the kinematic diffraction theory, and are shown to be able to reproduce almost all features of measured RHEED intensity oscillations from low-index surfaces.

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