Surface Orientation Influence on the Langmuir Evaporation Characteristics of GaAs Substrates

2018 ◽  
Vol 386 ◽  
pp. 21-26 ◽  
Author(s):  
Anna A. Spirina ◽  
Alla G. Nastovjak ◽  
Nataliya L. Shwartz
Keyword(s):  
Substrate Surface ◽  
Activation Energies ◽  
Surface Orientation ◽  
Interface Roughness ◽  
Liquid Gallium ◽  
Vicinal Surface ◽  
Vicinal Surfaces ◽  
Droplet Concentration ◽  
Gaas Substrates ◽  
Crystal Interface

The dependences of congruent evaporation temperature Tc and the desorption activation energies of GaAs components on the substrate surface orientation are analyzed using Monte Carlo simulation. On the vicinal surfaces with the (111)A orientation at temperatures exceeding Tc, the metal droplets start to grow at step edges, and, with the (111)B orientation, the droplets nucleate randomly on the terraces. The droplet concentration on the (111)B surface is higher than that on the (111)A surface. The droplet-crystal interface roughness is different for (111)A and (111)B orientations. The Tc of (111)B surfaces is lower than that of (111)A surfaces. For both surface orientations, Tc decreases when the vicinal surface terrace width is shorter than the double gallium diffusion length. The gallium and arsenic desorption activation energies dependence on the vicinal surface misorientation is demonstrated. A sharp increase in the arsenic desorption rate is observed with an increase of the (111)A surface coating with liquid gallium.

Observation of the CdTe-GaAs Interface by High Resolution Electron Microscopy

1984 ◽  
Vol 37 ◽  
Author(s):  
N. Otsuka ◽  
L. A. Kolodziejski ◽  
R. L. Gunshor ◽  
S. Datta ◽  
R. N. Bicknell ◽  
...  
Keyword(s):  
High Resolution ◽  
Film Growth ◽  
Substrate Surface ◽  
High Resolution Electron Microscopy ◽  
Gaas Substrates ◽  
Resolution Electron ◽  
Interfacial Structures ◽  
Substrate Preheating ◽  
High Resolution Electron Microscope

AbstractCdTe films have been grown on GaAs substrates with two types of interfaces - one with the epitaxial relation (111)CdTe║ (100)GaAs and the other with (100)CdTe║ (100)GaAs,. High resolution electron microscope observation of the two types of interfaces was carried out in order to determine the role of the substrate surface microstructure in determining the epitaxy. The interface of the former type shows a direct contact between the CdTe and GaAs crystals, while the interface of the latter type has a very thin oxide layer (∼10 Å in thickness) between the two crystals. These observations suggest that details of the substrate preheating cycle prior to film growth is the principle factor in determining which epitaxial relation occurs in this system. The relation between interfacial structures and the origin of the two epitaxial relations is discussed.

Effect of Copper Substrate Surface Orientation on the Reductive Functionalization of Graphene

2019 ◽  
Vol 31 (21) ◽  
pp. 8639-8648
Author(s):  
Xu Zhang ◽  
Da Luo ◽  
Hanyang Zhang ◽  
Dae Yeon Hwang ◽  
Sung O. Park ◽  
...  
Keyword(s):  
Substrate Surface ◽  
Copper Substrate ◽  
Surface Orientation ◽  
Effect Of Copper

Effect of Substrate-Surface Orientation on the N Incorporation in GaAsN Films on GaAs Grown by MOVPE

2008 ◽  
Vol 55-57 ◽  
pp. 825-828 ◽  
Author(s):  
P. Klangtakai ◽  
S. Sanorpim ◽  
S. Kuboya ◽  
R. Katayama ◽  
Kentaro Onabe
Keyword(s):  
Growth Rate ◽  
High Performance ◽  
Substrate Surface ◽  
Surface Orientation ◽  
X Ray Diffraction ◽  
N Content ◽  
Long Wavelength ◽  
The Difference ◽  
N Incorporation ◽  
Novel Structures

The GaAs1-xNx alloy semiconductor has been grown on GaAs (001), (111)A and (011) substrates by metalorganic vapor-phase epitaxy. High resolution X-ray diffraction and Raman scattering were employed to examine the effective N content and the growth rate, as a function of the substrate-surface orientation. The growth rate, which was assessed though the clear Pendellösung fringes, and the N content were found to change dramatically with the substrate-surface orientations. The N content was determined in the order (111)A > (001) > (011). While, the growth rate is in the order, (001) > (011) > (111)A. The effect of substrate-surface orientation on the N incorporation found in the present study is interpreted in terms of the difference in the growth rate on each surface orientation and the number of dangling bonds with which the N atoms can be trapped on the growing surface. Our results show that controlled nitrogen incorporating for GaAsN is successfully achieved and can be applied to the fabrication of some novel structures such as a spontaneous N content modulated structure, which is applicable to high performance long wavelength laser diodes.

Influences of substrate surface orientation on misfit accommodation in InGaP/GaAs heterostructures

1995 ◽  
Vol 257 (1) ◽  
pp. 72-76
Author(s):  
J.W. Lee ◽  
D.H. Shin ◽  
S.J. Kang ◽  
M.S. Oh ◽  
J.Y. Kim ◽  
...  
Keyword(s):  
Substrate Surface ◽  
Surface Orientation ◽  
Misfit Accommodation

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.

The relationship between the MOCVD parameters and the crystallinity, epitaxy, and domain structure of PbTiO3 films

1994 ◽  
Vol 9 (1) ◽  
pp. 156-163 ◽  
Author(s):  
G.R. Bai ◽  
H.L.M. Chang ◽  
C.M. Foster ◽  
Z. Shen ◽  
D.J. Lam
Keyword(s):  
Gas Phase ◽  
Deposition Temperature ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
Surface Orientation ◽  
Organic Chemical ◽  
Epitaxial Relationship ◽  
Domain Structures ◽  
Vapor Deposition Technique ◽  
The Relationship

Lead- and titanium-based oxide thin films were prepared by the metal-organic chemical vapor deposition technique (MOCVD) and the relationship between the film structures and the processing parameters, such as the ratio of Pb/Ti precursors in the gas phase, substrate materials, substrate surface orientation, and growth temperature, was systematically studied. It was found that whether a single-phase stoichiometric PbTiO3 film could be obtained depended on both the Pb/Ti precursor ratio in the gas phase and the deposition temperature. Under appropriate conditions, stoichiometric PbTiO3, films could be obtained on all the substrates including silicon, MgO, α-Al2O3, SrTiO3, and LaAlO3. The PbTiO3 films grown on silicon substrates were always polycrystalline, whereas epitaxial PbTiO3 films were obtainable on all the other substrates. For epitaxial PbTiO3 films, the epitaxial relationship, crystallinity, and domain structures were found to be a function of both the substrate materials and surface orientation as well as the deposition temperature. X-ray rocking curves (ω scan) of the (100) and (001) planes of PbTiO3 epitaxial film and PbTiO3 single crystal revealed the inherent nature of the domain structures in PbTiO3.

scholarly journals Uniaxial magnetic anisotropy induced by vicinal surfaces in half metallic La0.7Sr0.3MnO3 thin films

2009 ◽  
Vol 1198 ◽  
Author(s):  
Paolo Perna ◽  
Erika Jiménez ◽  
Francisco J. Terán ◽  
Laurence Méchin ◽  
Julio Camarero ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetic Anisotropy ◽  
Magnetization Reversal ◽  
Substrate Surface ◽  
Uniaxial Anisotropy ◽  
Current Theory ◽  
Vicinal Surfaces ◽  
Direction Parallel ◽  
Half Metallic ◽  
Crystalline Symmetry

AbstractWe present a detailed study of the angular dependence of the magnetization reversal at room temperature of well characterized epitaxial La0.7Sr0.3MnO3 (001) thin films grown onto SrTiO3 (001) vicinal substrates. The step edges at the substrate surface promote a topological modulation of the films along the step direction, breaking the four-fold magneto crystalline symmetry and favoring a two-fold magnetic anisotropy term. The competition between the biaxial and uniaxial anisotropy is depicted within the framework of the current theory, resulting in a vanishing biaxial contribution. The films hence show the magnetization easy (hard) direction parallel (perpendicular) to the steps direction. The thickness-dependent of both anisotropy and magnetization reversal are discussed in terms of topographic changes.

Influence of Er and O doses in Er-related emission in Al0.70Ga0.30As:Er

2001 ◽  
Vol 692 ◽  
Author(s):  
Shin-ichiro Uekusa ◽  
Tomoyuki Arai
Keyword(s):  
Activation Energy ◽  
Temperature Dependence ◽  
Room Temperature ◽  
Thermal Quenching ◽  
Activation Energies ◽  
Optimum Dose ◽  
Radiative Efficiency ◽  
Gaas Substrates ◽  
Pl Intensity

AbstractEr ions with doses ranging from 1×1013 cm−2 to 1×1015 cm−2 were implanted into Al0.70Ga0.30As on GaAs substrates. at 800 °C. Photoluminescence (PL) intensity of Er-related emission around 1.54 μm was enhanced by co-implanted oxygen (O). The optimum dose of Er ion was 1×1014 cm−2 and O ion was 1×1015 cm−2, respectively. Furthermore, from the temperature dependence of the PL intensity of sample implanted with the optimum dose, we estimated the values of E1, E2, and E3, the activation energies in order to investigate the rapid thermal quenching of Er ion in Al0.70Ga0.30As. We found that PL intensity of Er-related emission, in addition to O dose, was enhanced approximately twenty two times at room temperature. And from the temperature dependence of the lifetime of the optimum dose of Er and O, the value 245meV of EA, the activation energy for the decrease of the lifetime, was nearly equal to the value 235meV of E3. Based on the result, the decrease of the lifetime confirms that the radiative efficiency is lower; therefore, we propose that rapid thermal quenching occurs at temperatures above 200 K due to the decrease of the radiative efficiency.

Studies on the Adhesion of Au Films to GaAs

1988 ◽  
Vol 119 ◽  
Author(s):  
T. T. Bardin ◽  
J. G. Pronko ◽  
L. Senbetu ◽  
D. A. Kozak
Keyword(s):  
Adhesion Strength ◽  
Substrate Surface ◽  
Gaas Surface ◽  
Hydroxyl Groups ◽  
Controlled Atmospheres ◽  
Au Film ◽  
Characterization Techniques ◽  
Gaas Substrates ◽  
Film Adhesion ◽  
Poor Adhesion

AbstractThe influence of a number of substrate conditions and interfacial contaminants on the adhesion strength of thin Au films (10 to 100 nm thick) to GaAs substrates was studied. The GaAs surfaces were prepared by cleaving on the <110> plane under controlled atmospheres and conditions prior to depositing the Au film. Adhesion strengths were measured using the pinpull test. The study included standard characterization techniques to examine the substrate surface and the Au-GaAs interfaces. A direct correlation was found between cases of poor adhesion and the presence of hydroxyl groups on the GaAs surface. The influence of post evaporative treatments to improve the adhesion of specific cases was also studied.

Electronic and structural study of Pt-modified Au vicinal surfaces: a model system for Pt–Au catalysts

2014 ◽  
Vol 16 (26) ◽  
pp. 13329-13339 ◽  
Author(s):  
Mauricio J. Prieto ◽  
Emilia A. Carbonio ◽  
Shadi Fatayer ◽  
Richard Landers ◽  
Abner de Siervo
Keyword(s):  
Electronic Properties ◽  
Structural Study ◽  
Model System ◽  
Surface Orientation ◽  
Surface Alloy ◽  
Alloy Formation ◽  
Vicinal Surfaces

Morphology and electronic properties of Pt nanostructures are influenced by the underlying Au surface orientation and surface alloy formation, respectively.

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