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.

CRYSTAL GROWTH OF OXIDE THIN FILMS USING MASS-SEPARATED LOW-ENERGY O+ ION BEAMS

1994 ◽  
Vol 08 (01n02) ◽  
pp. 183-205 ◽  
Author(s):  
RYUSUKE KITA
Keyword(s):  
Thin Films ◽  
Low Temperatures ◽  
Oxygen Plasma ◽  
Molecular Beam ◽  
Ion Beams ◽  
Low Energy ◽  
Oxide Thin Films ◽  
High Quality ◽  
Mbe Growth ◽  
A New Technique

A new technique developed for growing high-quality oxide thin films by molecular beam epitaxy (MBE) is described. The technique uses low-energy and high density O + ion beams mass-separated from an oxygen plasma, as an oxidation source. Since O + ion beams have great oxidation ability and kinetic energy, the technique enables us to grow oxide films by MBE not only under ultrahigh vacuum comparable to the environment where semiconductors are prepared, but also at low temperatures. The application of the technique to the MBE growth of CuO, BaO, SrO and Sr–Cu–O thin films is also described.

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.

Study of high quality AlN layers grown on Si(111) substrates by plasma-assisted molecular beam epitaxy

1997 ◽  
Vol 2 ◽  
Author(s):  
M. A. Sánchez-García ◽  
E. Calleja ◽  
E. Monroy ◽  
F. J. Sánchez ◽  
F. Calle ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Growth Conditions ◽  
Buffer Layers ◽  
Structural Quality ◽  
Half Maximum ◽  
High Quality ◽  
Force Microscopy ◽  
Aln Buffer ◽  
Xrd Techniques

High quality AlN layers with full widths at half maximum values of 10 arcmin and average surface roughness (rms) of 48Å were grown by molecular beam epitaxy on Si(111) substrates. A systematic study and optimization of the growth conditions was performed in order to use these AlN layers as buffers in the growth of GaN films. Atomic force microscopy (AFM) and X-ray diffraction (XRD) techniques were employed to determine the surface and structural quality of the layers. Best AlN films were obtained at high substrate temperatures (Tsubs>900°C) and III/V ratios close to stoichiometry. Growth conditions with III/V ratios beyond stoichiometry (Al-rich) did not further improve the crystal quality. In these cases a higher substrate temperature is needed to prevent condensation of Al on the surface. GaN films with full width at half maximum of 10 arcmin and improved optical properties were grown on top of optimized AlN buffer layers.

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.

Film Growth, by Seeded Supersonic Beams, of Thiophene-Based Oligomers with Controlled Optical, Structural and Morphological Properties

1999 ◽  
Vol 598 ◽  
Author(s):  
Tullio Toccoli ◽  
Maurizio Ferrari ◽  
Sabina Ronchin ◽  
Alessandro Podestà ◽  
Paolo Milani ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Molecular Beam ◽  
Film Growth ◽  
Morphological Properties ◽  
Published Data ◽  
Film Properties ◽  
High Quality ◽  
Supersonic Molecular Beam ◽  
Supersonic Beams ◽  
Novel Approach

ABSTRACTA novel approach for the deposition of high quality films of oligothiophenes has been developed. It is based on an original seeded supersonic molecular beam combined with a UHV deposition chamber. This method gives an unprecedented control on film properties. Several T4 films under different beams conditions have been prepared and characterized by optical absorption, photoluminescence and TMAFM. Morphology, structure and optical response are controlled by the beam's parameters. Highly ordered films, up to several hundreds of nm thick, show well resolved vibronic structures in low temperatures PL as only the best published data on films a few monolayers thick do.

scholarly journals Твердые растворы In-=SUB=-x-=/SUB=-Al-=SUB=-1-x-=/SUB=-N: проблемы стабильности состава

2019 ◽  
Vol 53 (12) ◽  
pp. 1733
Author(s):  
В.Н. Брудный ◽  
М.Д. Вилисова ◽  
Л.Э. Великовский
Keyword(s):  
Gas Phase ◽  
Molecular Beam ◽  
Organometallic Compounds ◽  
Growth Conditions ◽  
Equilibrium Solubility ◽  
High Quality ◽  
Gan Hemt ◽  
Wide Range ◽  
Growing Conditions ◽  
Thick Layers

Abstract. The phase diagrams and growth conditions of InxAl1-xN solid solutions by magnetron sputtering, molecular beam and gas-phase epitaxy from organometallic compounds are analyzed. Mutual equilibrium solubility in a wide range of compositions of thick layers of this solution is close to zero. Moreover, the presence of elastic misfit stresses for thin InxAl1-xN films narrows the unstable mixing region. Optimization of the growing conditions makes it possible to obtain the homogeneous high-quality InxAl1-xN layers suitable for the production of a barrier layer in an InAlN/GaN HEMT.

High quality AlGaAs layers grown by molecular beam epitaxy at low temperatures

1992 ◽  
Vol 3 (1) ◽  
pp. 11-15
Author(s):  
K. H. Chang ◽  
J. S. Wu ◽  
D. G. Liu ◽  
D. C. Liou ◽  
C. P. Lee
Keyword(s):  
Molecular Beam Epitaxy ◽  
Low Temperatures ◽  
Molecular Beam ◽  
High Quality

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.

High speed growth of MAPbBr3 single crystals via low-temperature inverting solubility: enhancement of mobility and trap density for photodetector applications

Nanoscale ◽  
2021 ◽  
Author(s):  
Yunae Cho ◽  
Hye Ri Jung ◽  
Yeon Soo Kim ◽  
Yejin Kim ◽  
Joohee Park ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Low Temperature ◽  
Low Temperatures ◽  
High Speed ◽  
Single Crystal Growth ◽  
Complete Dissolution ◽  
High Quality ◽  
Optoelectronic Application ◽  
Hybrid Perovskite ◽  
First Time

High-quality CH3NH3PbBr3 hybrid perovskite single crystal growth and outstanding optoelectronic application using the complete dissolution at low temperatures based on low temperature solubility, which has been demonstrated for the first time.

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.

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