Modeling Multilayer Pyramidal-Like
Adsorbate Structures Growth During
Deposition at Homoepitaxy
Alina V. Dvornichenko and Olga M. Shchokotova
1 Introduction
Molecular-beam epitaxy (MBE) serves as a technique that is frequently used to
fabricate single crystals which inherit atomic structure of the substrate. During the
epitaxial growth, the deposited material forms a beam of neutral atoms. These atoms
attach the substrate and can be adsorbed according to chemical bonding and become
adatoms. Adsorbed atoms can diffuse on a substrate by probing energetically more
favorable positions and interact with each other by making clusters of adsorbate.
Isolated adatoms with nonzero probability can desorb back in vapor phase. Usually,
the layer-by-layer growth during epitaxy provides formation of a new monolayer of
adatoms. In the case of incomplete atomic layer, such process results in a formation
of two-dimensional adsorbate structures on a substrate. In such a case, the interface
roughness takes small values and the growing surface can be considered as atomically
flat. At the same time the process of the smooth epitaxial growth is realized at initial
stages of exposing (transient) and according to the statistical mechanics could not
be considered as a stationary one. As it was shown before, during the layer-bylayer growth, the roughness of the surface grows in time for large substrate and long
exposing time [1–4]. This effect becomes a result of incident flux fluctuations, which
leads to accelerating the lateral diffusion of adatoms after some initial transient.
Such processes will lead to monotonical increase in the surface roughness and at
large exposing time it attains the stationary value. Hence, during epitaxial growth,
interacting adatoms will self-organize into three-dimensional pyramidal islands. Here
the morphology of a growing surface will be determined by the following processes:
adsorption, desorption, and nucleation on top of islands; edge diffusion, diffusion
down step, and dimer diffusion; attachment/detachment from island boundaries and
island coalescence [1, 5, 6].
A. V. Dvornichenko (B)
Sumy State University, 2 Rimskii -Korsakov St., Sumy 40007, Ukraine
e-mail: alina.dvorni4enko@ukr.net
O. M. Shchokotova
Institute of Applied Physics, National Academy of Sciences of Ukraine,
58 Petropavlovskaya St., Sumy 40000, Ukraine
© Springer Nature Switzerland AG 2021
O. Fesenko and L. Yatsenko (eds.), Nanomaterials and Nanocomposites,
Nanostructure Surfaces, and Their Applications, Springer Proceedings
in Physics 246, https://doi.org/10.1007/978-3-030-51905-6_31
425
Adsorbate Structures Growth During
Deposition at Homoepitaxy
Alina V. Dvornichenko and Olga M. Shchokotova
1 Introduction
Molecular-beam epitaxy (MBE) serves as a technique that is frequently used to
fabricate single crystals which inherit atomic structure of the substrate. During the
epitaxial growth, the deposited material forms a beam of neutral atoms. These atoms
attach the substrate and can be adsorbed according to chemical bonding and become
adatoms. Adsorbed atoms can diffuse on a substrate by probing energetically more
favorable positions and interact with each other by making clusters of adsorbate.
Isolated adatoms with nonzero probability can desorb back in vapor phase. Usually,
the layer-by-layer growth during epitaxy provides formation of a new monolayer of
adatoms. In the case of incomplete atomic layer, such process results in a formation
of two-dimensional adsorbate structures on a substrate. In such a case, the interface
roughness takes small values and the growing surface can be considered as atomically
flat. At the same time the process of the smooth epitaxial growth is realized at initial
stages of exposing (transient) and according to the statistical mechanics could not
be considered as a stationary one. As it was shown before, during the layer-bylayer growth, the roughness of the surface grows in time for large substrate and long
exposing time [1–4]. This effect becomes a result of incident flux fluctuations, which
leads to accelerating the lateral diffusion of adatoms after some initial transient.
Such processes will lead to monotonical increase in the surface roughness and at
large exposing time it attains the stationary value. Hence, during epitaxial growth,
interacting adatoms will self-organize into three-dimensional pyramidal islands. Here
the morphology of a growing surface will be determined by the following processes:
adsorption, desorption, and nucleation on top of islands; edge diffusion, diffusion
down step, and dimer diffusion; attachment/detachment from island boundaries and
island coalescence [1, 5, 6].
A. V. Dvornichenko (B)
Sumy State University, 2 Rimskii -Korsakov St., Sumy 40007, Ukraine
e-mail: alina.dvorni4enko@ukr.net
O. M. Shchokotova
Institute of Applied Physics, National Academy of Sciences of Ukraine,
58 Petropavlovskaya St., Sumy 40000, Ukraine
© Springer Nature Switzerland AG 2021
O. Fesenko and L. Yatsenko (eds.), Nanomaterials and Nanocomposites,
Nanostructure Surfaces, and Their Applications, Springer Proceedings
in Physics 246, https://doi.org/10.1007/978-3-030-51905-6_31
425