Ordered Ternary Alloys by Atomic Layer Epitaxy

1989 ◽  
Vol 160 ◽  
Author(s):  
B.T. Mcdermott ◽  
K.G. Reid ◽  
A. Dip ◽  
N.A. El-Masry ◽  
S.M. Bed Air ◽  
...  
Keyword(s):  
Gas Phase ◽  
Growth Temperature ◽  
Gaas Substrate ◽  
Atomic Layer ◽  
Ternary Alloys ◽  
Atomic Layer Epitaxy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lattice Matching ◽  
Gaas Substrates

AbstractWe report on the successful growth of GalnP on GaAs substrate by Atomic Layer Epitaxy using organometallic and hydride sources. Growth was achieved by sequential exposure of the substrate to TMGa, PH3, TEIn and PH3. X-ray diffraction showed compositional lattice-matching optimally at 550°C with arbitrary choices of the mole fractions of the precursors in the gas phase. TEM also confirmed the highest ordering at this growth temperature on (100) substrates. Uniformity was excellent using Atomic Layer Epitaxy. Growth on (111)A GaAs substrates produced no evidence of the ordered CuPt phase present on (100) substrates.

InAs and InGaAs Growth by Chloride Atomic Layer Epitaxy

1989 ◽  
Vol 160 ◽  
Author(s):  
H. Shimawaki ◽  
Y. Kato ◽  
A. Usui
Keyword(s):  
Growth Factor ◽  
Growth Temperature ◽  
Growth Rates ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Superlattice Structures ◽  
Inp Substrates

AbstractInAs chloride ALE has been carried out in detail, resulting in successful InGaAs ALE on (111)B InP substrates. InAs growth of 0.9 ML/cycle is obtained for (111)B InAs substrates at temperatures below 375 °C, while growth rates for (100) and (111)A substrates steadily decrease with increases in growth temperature. The growth rates are independent of InCI pressure at 375 °C, suggesting a self-limiting growth factor in InAs chloride ALE. (GaAs)1(InAs)1 and (GaAs)2(InAs)2 superalloys can be prepared on (111)B InP substrates at 375 °C. Growth rates and crystal compositions for both layers agree well with the values expected for ideal superalloys. The presence of superlattice structures is indicated by X-ray diffraction measurement,

scholarly journals Characteristics of MOCVD-Grown High-Quality CdTe Layers on GaAs Substrates

1995 ◽  
Vol 18 (4) ◽  
pp. 247-258
Author(s):  
P. W. Sze ◽  
K. F. Yarn ◽  
Y. H. Wang ◽  
M. P. Houng ◽  
G. L. Chen
Keyword(s):  
Growth Temperature ◽  
Vapor Deposition ◽  
Gaas Substrate ◽  
Concentration Ratio ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Double Crystal ◽  
X Ray ◽  
Gaas Substrates ◽  
Growth System

CdTe epitaxial layers are grown successfully on a (100)-GaAs substrate by metalorganic chemical vapor deposition (MOCVD) using dimethylcadrnium (DMCd) and diethyltelluride (DETe) as alkyl sources. The CdTe epilayers grown between 365°C and 380°C possess the best surface morphology. DETe is used as the controlling species of this growth system. Typical growth rates are varied from 2.51µm/hr to 5.31µm/hr. Low-temperature (12K) photoluminscence (PL) measurements reveal that 380°C is the best growth temperature and the full width at half maximum (FWHM) of the dominated peak is about 1.583eV by the bound-exciton emission of 9.38meV. The double crystal X-ray rocking curves (DCRC) indicate that the FWHM decreases while increasing the epilayer thickness and approaches a stable value about 80 arc sec under the growth rate of 5.2µm/hr, the growth temperature of 380°C and the DETe/DMCd concentration ratio of 1.7. The value of 80 arc sec in FWHM is the smallest one ever reported to date.

Electrochemical Atomic-Layer Epitaxy: Electrodeposition of III-V and II-VI Compound Semiconductors

1999 ◽  
Vol 581 ◽  
Author(s):  
Travis L. Wade ◽  
Billy H. Flowers ◽  
Raman Vaidyanathan ◽  
Kenneth Mathe ◽  
Clinton B. Maddox ◽  
...  
Keyword(s):  
Compound Semiconductors ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Infrared Reflection ◽  
Epitaxial Deposition ◽  
Electrochemical Atomic Layer Epitaxy

ABSTRACTElectrochemical atomic-layer epitaxy (EC-ALE) is an approach to electrodepositing thin-films of compound semiconductors. It takes advantage of underpotential deposition (UPD), deposition of a surface limited amount (a monolayer or less) of an element at a potential less negative than bulk deposition, to form a thin-film of a compound--one atomic layer at a time. Ideally, the 2-D growth mode should promote epitaxial deposition.Many II-VI and a few III-V compounds have been formed by EC-ALE. TI-VI films such as CdSe, CdS, and CdTe have been successfully formed. In addition, deposition of III-V compounds of InAs and InSb are being explored, along with initial studies of GaAs deposition. Depositions of the I-VI systems are better understood so this report will focus on the III-V's, particularly InAs and InSb.Building compounds an atomic layer at a time lends electrochemical-ALE to nanoscale technology. Deposited thickness ranged from a few nanometers to a few hundred. The films are typically characterized by atomic-force microscopy (AFM), X-ray diffraction (XRD), electron microprobe analysis (EPMA) and ellipsometry. InAs deposits are also characterized by infrared reflection absorption.

Atomic Layer Epitaxy of (Si1-xC1-y)Gex+y Layers on 4H-SiC

2006 ◽  
Vol 527-529 ◽  
pp. 1559-1562
Author(s):  
Jörg Pezoldt ◽  
Thomas Kups ◽  
Petia Weih ◽  
Thomas Stauden ◽  
Oliver Ambacher
Keyword(s):  
Molecular Beam Epitaxy ◽  
Substrate Temperature ◽  
Epitaxial Growth ◽  
Molecular Beam ◽  
Atomic Layer ◽  
Ternary Alloys ◽  
Energy Dispersive ◽  
Atomic Layer Epitaxy ◽  
X Ray ◽  
Edx Analysis

3C-(Si1-xC1-y)Gex+y ternary alloys were grown on 8.5° off axis 4H-SiC substrates by solid source molecular beam epitaxy in a temperature range between 750°C and 950°C. Energy dispersive X-ray (EDX) analysis revealed a decrease of the Ge incorporation versus substrate temperature. This effect is due to the fixed Si/Ge ratio during the epitaxial growth. The Ge distribution within the grown epitaxial layers was found to be nearly homogeneous. The investigations by atomic location by channeling enhanced microanalysis allowed the conclusion that Ge is located mainly at Si lattice sites.

Epitaxial tilt of partially relaxed InGaAs layers grown on (100) GaAs substrates

1992 ◽  
Vol 70 (10-11) ◽  
pp. 838-842
Author(s):  
P. Maigné ◽  
A. P. Roth ◽  
C. Desruisseaux ◽  
D. Coulas
Keyword(s):  
Residual Strain ◽  
Gaas Substrate ◽  
Strain Relaxation ◽  
Azimuthal Angle ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Monoclinic Symmetry ◽  
X Ray ◽  
Mismatch Strain ◽  
Gaas Substrates

The structural properties of partially relaxed InxGa1−xAs layers grown on (100) GaAs substrates have been investigated, using high-resolution X-ray diffraction, in order to better understand the mechanisms responsible for the relaxation of the mismatch strain. From symmetric [400] reflections recorded as functions of the azimuthal angle [Formula: see text], the (100) InGaAs planes are found to be tilted with respect to the (100) GaAs substrate planes. The tilt magnitude is first seen to decrease then to increase with layer thickness. The direction of the tilt changes from [01-1] to [00-1] in the range of thickness investigated. From [422] asymmetric reflections, the average in-plane lattice parameter, the indium composition as well as the percentage of relaxation can be measured. Our values for relaxation are in qualitative agreement with the Dodson and Tsao model of strain relaxation (Appl. Phys. Lett. 51, 1710 (1987)). In addition, our data show an anisotropy in residual strain along <011> directions. This anisotropy increases with the amount of strain relieved and changes the crystal symmetry of the cell from tetragonal to monoclinic. This monoclinic symmetry can be characterized by an angle β that measures the angle between 90° and the inner angles of the new crystallographic cell. As for the anisotropy in residual strain, |3 increases with the amount of strain relieved. Correlations between tilt magnitude and tilt direction with the formation of 60° type dislocations are discussed.

Determination of growth parameters for atomic layer epitaxy using reflectance difference spectroscopy

1996 ◽  
Vol 74 (S1) ◽  
pp. 85-88 ◽  
Author(s):  
R. Arès ◽  
C. A. Tran ◽  
S. P. Watkins
Keyword(s):  
Growth Rate ◽  
Growth Parameters ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
Gas Flows ◽  
Difference Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reflectance Difference Spectroscopy

Reflectance difference spectroscopy (RDS) has been used to monitor the anisotropy of the surface of InAs and GaAs grown by atomic layer epitaxy (ALE). Saturation of the RDS signal is observed when the surface is fully covered with one monolayer of the impinging surface species. This property is used to optimize the growth interruptions for the ALE cycle. Good correlation of the RDS saturation is observed with growth-rate measurements obtained by X-ray diffraction (XRD). When exposure times are sufficiently long for saturation to be observed in the RDS signal, a growth rate of one monolayer per cycle (1 ML/cycle) is achieved. In principle all the different growth parameters such as exposure and purge times as well as gas flows can be determined in a few cycles performed on a single substrate. Without RDS the same results would require several growth runs and time consuming X-ray characterization.

Electrodeposition of CU2SE thin films by Electrochemical Atomic Layer Epitaxy (EC-ALE).

2002 ◽  
Vol 744 ◽  
Author(s):  
Raman Vaidyanathan ◽  
Mkhulu K. Mathe ◽  
Patrick Sprinkle ◽  
Steve M Cox ◽  
Uwe Happek ◽  
...  
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Atomic Layer ◽  
Atomic Ratio ◽  
Atomic Layer Epitaxy ◽  
Cyclic Voltammograms ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrochemical Atomic Layer Epitaxy ◽  
Absorption Measurements

ABSTRACTElectrochemical atomic-layer epitaxy (EC-ALE) is an approach to electrodepositing thin-films of compound semiconductors. It takes advantage of underpotential deposition (UPD), deposition of a surface limited amount (a monolayer or less) of an element at a potential less negative than bulk deposition, to form a thin-film of a compound--one atomic layer at a time. Ideally, the 2-D growth mode should promote epitaxial deposition.We report the formation of compound Cu2Se, at room temperature by electrochemical atomic layer epitaxy (EC-ALE). Cyclic voltammograms were used to determine the deposition potentials of each element. An automated deposition program was used to form 750 cycles of Cu2Se thin films. Electron probe microanalysis was done to determine the stoichiometry of the thin films. X-ray diffraction of the 200 cycle deposit indicated the presence of polycrystalline Cu2Se. The atomic ratio of Cu/Se in the thin films was found to be 2. Band gap of the thin films were determined by reflection absorption measurements. The band gap of the 200 cycle Cu2Se films was found to be 1.6 eV. X-ray diffraction of 350 and 750 cycle Cu2Se films, indicated the deposits consisted of Cu3Se2 and Cu2Se.

Epitaxial Layer Misorientation in CdTe on GaAs‡

1990 ◽  
Vol 202 ◽  
Author(s):  
H. E. Inglefield ◽  
R. J. Matyi ◽  
R. Korenstein
Keyword(s):  
Epitaxial Layer ◽  
Gaas Substrate ◽  
Dislocation Model ◽  
Azimuthal Direction ◽  
X Ray Diffraction ◽  
Azimuthal Dependence ◽  
X Ray ◽  
Gaas Substrates ◽  
Cdte Films ◽  
Hot Wall Epitaxy

ABSTRACTX-ray diffraction has been used to characterize the relative misorientation of [001] and [111] CdTe layers grown by hot-wall epitaxy on GaAs substrates. The magnitude of the misorientation of the CdTe epitaxial layer relative to the GaAs substrate depends on the magnitude of the miscut of the substrate; in addition, the [111] oriented CdTe exhibited significantly larger misorientations than did the [001] CdTe films. The azimuthal direction of the tilt of the epitaxial layer depends strongly on the nominal crystallographic orientation of the film. The [111] CdTe exhibited an azimuthal dependence of the tilt that is approximately coincident with the miscut of the substrate, while the azimuthal direction of tilt in the [001] CdTe layers differed from the substrate miscut direction by as much as 116°. These observations of epitaxial layer misorientation are discussed in terms of a dislocation model for layer tilt and azimuthal rotation in lattice-mismatched epitaxial systems.

X-ray diffraction study of thin electroluminescent ZnS films grown by atomic layer epitaxy

1981 ◽  
Vol 67 (2) ◽  
pp. 573-583 ◽  
Author(s):  
V.-P. Tanninen ◽  
M. Oikkonen ◽  
T. O. Tuomi
Keyword(s):  
Diffraction Study ◽  
Atomic Layer ◽  
Atomic Layer Epitaxy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zns Films
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