Formation of Two-Dimensional Islands on Si(111) Surface During Homoepitaxial Growth

2014 ◽  
Vol 9 (2) ◽  
pp. 156-166
Author(s):  
Dmitriy Rogilo ◽  
Ludmila Fedina ◽  
Sergey Kosolobov ◽  
Aleksandr Latyshev
Keyword(s):  
Electron Microscopy ◽  
Substrate Temperature ◽  
Critical Nucleus ◽  
Two Dimensional ◽  
Nucleus Size ◽  
Island Nucleation ◽  
Homoepitaxial Growth ◽  
Reflection Electron Microscopy ◽  
Atomically Flat

The nucleation of two-dimensional Si islands has been studied by in situ ultrahigh vacuum reflection electron microscopy on extra-large (~ 10–100 μm) atomically flat terraces of Si(111) surface. The dependence of two-dimensional island concentration N2D on substrate temperature T and silicon deposition rate R is found to obey relation N2D ן Rχ exp(E2D/kT) with χ≈0.58 or 0.82 and E2D ≈ 1.77 eV or 1.02 eV on the Si(111) surface with (7×7) or (1×1) structure, respectively. The critical nucleus during the growth on the extra-large terraces is found to consist of i = 1 particle at T ~ 700°С, and the critical nucleus size increases to i = 7–10 on terraces with smaller width, which is caused by the competition between the 2D island nucleation and the interaction of adatoms with steps bordering the critical terrace

scholarly journals Влияние электромиграции на зарождение вакансионных островков на поверхности Si(100) при сублимации

2019 ◽  
Vol 53 (6) ◽  
pp. 805
Author(s):  
С.В. Ситников ◽  
Е.Е. Родякина ◽  
А.В. Латышев
Keyword(s):  
Electron Microscopy ◽  
Theoretical Model ◽  
Temperature Dependence ◽  
Effective Charge ◽  
Positive Sign ◽  
Nucleation Center ◽  
Island Nucleation ◽  
Reflection Electron Microscopy ◽  
Elementary Charge

AbstractBy means of in situ ultrahigh vacuum reflection electron microscopy, the nucleation of vacancy islands on wide terraces of the Si(100) surface is investigated. The temperature dependence of the displacement of a vacancy island nucleation center is determined in the process of heating a sample with a dc electric current. On the basis of a theoretical model, the effective electric charge of addimers is estimated in the direction across dimer rows of the surface. The effective charge has a positive sign and does not exceed 15 units of the elementary charge in the temperature range of 1020–1120°C.

Electromigration of Silicon Adatoms on Silicon (111) Surface

2011 ◽  
Vol 6 (2) ◽  
pp. 65-76
Author(s):  
Ekaterina E. Rodyakina ◽  
Sergey S. Kosolobov ◽  
Aleksandr V. Latyshev
Keyword(s):  
Electron Microscopy ◽  
Experimental Data ◽  
Effective Charge ◽  
Ex Situ ◽  
Equilibrium Conditions ◽  
Force Microscopy ◽  
Homoepitaxial Growth ◽  
Atomic Force ◽  
Reflection Electron Microscopy

Existence of adatom gradient concentration on surface between step bunches was shown under sublimation, homoepitaxial growth and near equilibrium conditions on silicon (111) surface at above 900 ºС by means of in situ ultrahigh vacuum reflection electron microscopy and ex situ atomic force microscopy. It is experimentally confirmed that adatom have negative (at 1 100 ºС) and positive (at 1 300 ºС) effective charge. We found out the sign of adatom effective charge independent on the supersaturation volume on the surface. On the hasement of experimental data we evaluated the effective charge of adatom at 1 280ºС; this quantity is placed between 0,07 ± 0,01 and 0,17 ± 0,02 of electron unit

In SituReflection Electron Microscopy of Ge Island Nucleation on Mesa Structures

2004 ◽  
Vol 10 (1) ◽  
pp. 105-111 ◽  
Author(s):  
F.M. Ross ◽  
M. Kammler ◽  
M.E. Walsh ◽  
M.C. Reuter
Keyword(s):  
Electron Microscopy ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Island Nucleation ◽  
Annealing Conditions ◽  
Reflection Electron Microscopy ◽  
Kinetics Of ◽  
Nonplanar Surface

We have usedin situelectron microscopy to observe the nucleation of Ge islands on lithographically patterned Si(001) mesas. Images were obtained at video rate during chemical vapor deposition of Ge, using a reflection electron microscopy geometry that allows nucleation to be observed over large areas. By comparing the kinetics of nucleation and coarsening on substrates modified by different annealing conditions, we find that the final island arrangement depends on the nature of the mesa sidewalls, and we suggest that this may be due to changes in diffusion of Ge across the nonplanar surface.

SREM observation of the interaction between the in-situ deposited Pd small particles and MgO cleavage surface

1986 ◽  
Vol 44 ◽  
pp. 382-383
Author(s):  
H.-J. Ou
Keyword(s):  
Electron Microscopy ◽  
Small Particle ◽  
Small Particles ◽  
Cleavage Surface ◽  
Metallic Particles ◽  
Microscopy Technique ◽  
Ceramic Surfaces ◽  
Reflection Electron Microscopy ◽  
New Perspective

The understanding of the interactions between the small metallic particles and ceramic surfaces has been studied by many catalyst scientists. We had developed Scanning Reflection Electron Microscopy technique to study surface structure of MgO hulk cleaved surface and the interaction with the small particle of metals. Resolutions of 10Å has shown the periodic array of surface atomic steps on MgO. The SREM observation of the interaction between the metallic particles and the surface may provide a new perspective on such processes.

Parabolas from Reconstructed Surfaces Observed in Convergent-Beam RHEED Patterns

1990 ◽  
Vol 48 (2) ◽  
pp. 398-399
Author(s):  
M. Gajdardziska-Josifovska
Keyword(s):  
Electron Microscopy ◽  
High Energy ◽  
Two Dimensional ◽  
High Energy Electron ◽  
Reflection And Transmission ◽  
Experimental Diffraction Pattern ◽  
Surface Resonance ◽  
Reconstructed Surfaces ◽  
Reflection Electron Microscopy ◽  
Convergent Beam

Parabolas have been observed in the reflection high-energy electron diffraction (RHEED) patterns from surfaces of single crystals since the early thirties. In the last decade there has been a revival of attempts to elucidate the origin of these surface parabolas. The renewed interest stems from the need to understand the connection between the parabolas and the surface resonance (channeling) condition, the latter being routinely used to obtain higher intensity in reflection electron microscopy (REM) images of surfaces. Several rather diverging descriptions have been proposed to explain the parabolas in the reflection and transmission Kikuchi patterns. Recently we have developed an unifying general treatment in which the parabolas are shown to be K-lines of two-dimensional lattices. Here we want to review the main features of this description and present an experimental diffraction pattern from a 30° MgO (111) surface which displays parabolas that can be attributed to the surface reconstruction.

Initial stages of silicon homoepitaxy studied by in situ reflection electron microscopy

1989 ◽  
Vol 113 (2) ◽  
pp. 421-430 ◽  
Author(s):  
A. V. Latyshev ◽  
A. L. Aseev ◽  
A. B. Krasilnikov ◽  
S. I. Stenin
Keyword(s):  
Electron Microscopy ◽  
Reflection Electron Microscopy

REM Studies of Adsorption-Induced Phase Transitions and Faceting in the Si(111)-Au System

1998 ◽  
Vol 05 (03n04) ◽  
pp. 653-663 ◽  
Author(s):  
Koyu Aoki ◽  
Hiroki Minoda ◽  
Yasumasa Tanishiro ◽  
Katsumichi Yagi
Keyword(s):  
Electron Microscopy ◽  
Phase Transitions ◽  
Surface Structure ◽  
Lower Side ◽  
Domain Boundaries ◽  
Adsorption Processes ◽  
Reflection Electron Microscopy ◽  
Step Down ◽  
Successive Phase

Initial stages of Au adsorption processes on Si(111)-(7 × 7) surfaces at ~780°C, a temperature range where the surface structure undergoes successive phase transitions [(7 × 7)–("1 × 1")–(5×2)–("1 × 1")], were observed in situ by reflection electron microscopy. All of the phase transitions are heterogeneous on the surface and start at surface atomic steps. During Au adsorption on Si(111)-(7 × 7), and subsequently on Si(111)-("1 × 1") surface with wide terraces, steps advance toward the step-down direction. At a Au coverage of ~0.3 ML, the 5 × 2 structure nucleates at step edges, and the nuclei expand both to the lower side terraces and to the higher side terraces. At this stage, an effect of current for heating the specimen was noted. From measurements of such movements of the steps and the domain boundaries, the density of Si atoms in the "1 × 1" phase is estimated to be 1.3–1.7 ML at a Au coverage of ~0.3 ML. Au adsorption on Si(111) surfaces with narrow terraces causes bunching of the steps. After nucleation of the 5 × 2 structure, the bunched [Formula: see text] steps become straight along the [Formula: see text] direction, and are transformed into the (335) facet planes at a Au coverage of 0.50 ML. It was found that the (335) facet planes are stabilized by adsorbed Au atoms. Destruction of the (335) facet is noted at a Au coverage of 0.73 ML.

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