Atomic-Scale Simulation of Silicon Atomic Beam Deposition

1987 ◽  
Vol 91 ◽  
Author(s):  
Brian W. Dodson
Keyword(s):  
Low Energy ◽  
Atomic Scale ◽  
Many Body ◽  
Energy Beam ◽  
Empirical Potential ◽  
Semiconductor Structures ◽  
Local Lattice ◽  
Atomic Beam Deposition ◽  
Grazing Angles ◽  
Beam Deposition

ABSTRACTThe mechanisms which control low energy (10–100 eV) beam deposition of silicon onto a relaxed (111) silicon substrate have been studied using a molecular dynamics technique. A many-body empirical potential was used to describe the covalent Si-Si bonding. 10 eV silicon beams with near-perpendicular incidence were simulated to study capture mechanisms and the local lattice excitation resulting from impact. Grazing angles of incidence (3°–30°) were studied for beam energies of 20–100 eV. For incidence angles less than an energy- and orientation-dependent critical value, the phenomenon of ‘surface channeling’ is predicted, in which the incoming particle is steered parallel to, and roughly 2 Å above, the surface of the substrate through inelastic substrate interactions. The phenomena seen in low-energy beam deposition offer new avenues of control over growth of modulated semiconductor structures.

Atomistic Simulation of Low-Energy Beam Deposition

1988 ◽  
Vol 100 ◽  
Author(s):  
Brian W. Dodson
Keyword(s):  
Atomistic Simulation ◽  
Incident Beam ◽  
Initial Energy ◽  
Low Energy ◽  
Many Body ◽  
Near Surface ◽  
Energy Beam ◽  
Beam Incident ◽  
Lattice Damage ◽  
Beam Deposition

ABSTRACTLow-energy (50 eV) homoepitaxial beam deposition of silicon is simulated using many-body silicon potentials and molecular dynamics techniques. Results are presented for the case of a 50 eV neutral silicon beam incident on the (2×1) dimer reconstructed Si(100) surface. The beam is aligned along (110) symmetry directions, which are the most natural channeling directions in the silicon lattice. Roughly 10% of the incident beam atoms are scattered from the surface with a small fraction of their initial energy. About half of the incident atoms penetrate the lattice, but scatter strongly and come to rest within 10–15Å of the surface. The remainder are steered accurately into the bulk (110) channels, where they penetrate some 30–100 Å into the lattice. Those atoms which do not undergo bulk channeling cause considerable lattice damage to the near-surface (depth ≥10Å) region.

scholarly journals Study of Icaritin Films by Low-Energy Electron Beam Deposition

2021 ◽  
Vol 23 (2) ◽  
pp. 77
Author(s):  
Tongfei Cheng ◽  
Jinxing Cao ◽  
Xiaohong Jiang ◽  
M.A. Yarmolenko ◽  
A.A. Rogachev ◽  
...  
Keyword(s):  
Electron Beam ◽  
In Vitro Cytotoxicity ◽  
Low Energy ◽  
Cytotoxicity Test ◽  
Soaking Time ◽  
Energy Beam ◽  
Electron Beam Deposition ◽  
Relative Cell Viability ◽  
Beam Deposition

In this paper, icaritin film was prepared by low-energy beam electron beam deposition (EBD). The material test showed that the structure and composition of icaritin were not changed after electron beam deposition. Then, the film was sliced and immersed in simulated body fluids, it can be seen that the film was released quickly in the first 7 days. With the extension of soaking time, the release rate gradually slowed down, and the release amount exceeded 90% in about 20 days. In vitro cytotoxicity test showed that the relative cell viability rate of the film was still 92.32±1.30% (p<0.05), indicating that the film possessed excellent cytocompatibility.

Self-organization of Te clusters in nanofilm by low energy beam deposition

1998 ◽  
Vol 244 (5) ◽  
pp. 407-412 ◽  
Author(s):  
P.P. Chen ◽  
Z.Y. Wang ◽  
S.W. Yu ◽  
J.M. Hong ◽  
P.R. Poulsen ◽  
...  
Keyword(s):  
Low Energy ◽  
Self Organization ◽  
Energy Beam ◽  
Beam Deposition

Atomic Beam Interactions with Silicon (111) Surfaces: A Molecular Dynamics Study

1986 ◽  
Vol 74 ◽  
Author(s):  
Brian W. Dodson ◽  
Paul A. Taylor
Keyword(s):  
Molecular Dynamics ◽  
Atomic Beam ◽  
Beam Momentum ◽  
Low Energy ◽  
Many Body ◽  
Surface Geometry ◽  
Symmetry Direction ◽  
Beam Surface ◽  
Grazing Angles ◽  
Channeling Effect

AbstractLow energy (5–20 eV) atomic beam-surface interactions have been studied using a molecular dynamics technique. Silicon atoms are directed at an unreconstructed (111) silicon substrate either perpendicular to the surface or at grazing angles of incidence from 10–35°. The Si-Si interaction is treated using an empirical many-body silicon potential so that the effects of covalent bonding are included. At general beam orientations relative to the surface, low energy atoms are rapidly adsorbed at the surface, whereas at higher energies they either bounce off the surface or penetrate into the substrate. However, when the surface component of beam momentum is parallel to a (100) symmetry direction, Si atoms, under certain conditions, are found to channel along the surface rows, resulting in very little local excitation of the surface geometry and only gradual energy loss. The vertical momentum is carried away by substrate lattice vibrations, and the particle is guided along the surface by interaction with the atoms making up the surface ‘half-channels’. This surface channeling effect offers considerable promise for delicate control of the beam-induced annealing/growth of non-equilibrium surface geometries, and thus for high-quality growth at low temperatures.

Interaction of a 10 eV silicon beam with the Si(111) surface: A molecular dynamics study

1987 ◽  
Vol 2 (6) ◽  
pp. 805-808 ◽  
Author(s):  
Brian W. Dodson ◽  
Paul A. Taylor
Keyword(s):  
Molecular Dynamics ◽  
Vibrational Excitation ◽  
Covalent Binding ◽  
Low Energy ◽  
Energy Beam ◽  
Substrate Structure ◽  
Deposition Processes ◽  
First Time ◽  
Beam Deposition ◽  
Silicon Beam

The interaction of a low-energy silicon beam with a silicon substrate has been simulated. The combined effects of vibrational lattice excitation and of covalent binding have been included for the first time by using a molecular dynamics technique and an empirical potential that accurately describes the covalent Si–Si interactions. A 10 eV silicon beam was directed normal to a silicon (111) substrate. Sticking ratio, penetration depth, substrate structure, and vibrational excitation of the substrate are quantitatively determined. The special features of such low-energy beam deposition relative to thermal deposition processes are discussed.

scholarly journals Probing resonating valence bond states in artificial quantum magnets

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kai Yang ◽  
Soo-Hyon Phark ◽  
Yujeong Bae ◽  
Taner Esat ◽  
Philip Willke ◽  
...  
Keyword(s):  
Quantum Information Processing ◽  
Energy Levels ◽  
Finite Size ◽  
Valence Bond ◽  
Exchange Interactions ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Many Body ◽  
Quantum Magnets ◽  
Resonating Valence Bond

AbstractDesigning and characterizing the many-body behaviors of quantum materials represents a prominent challenge for understanding strongly correlated physics and quantum information processing. We constructed artificial quantum magnets on a surface by using spin-1/2 atoms in a scanning tunneling microscope (STM). These coupled spins feature strong quantum fluctuations due to antiferromagnetic exchange interactions between neighboring atoms. To characterize the resulting collective magnetic states and their energy levels, we performed electron spin resonance on individual atoms within each quantum magnet. This gives atomic-scale access to properties of the exotic quantum many-body states, such as a finite-size realization of a resonating valence bond state. The tunable atomic-scale magnetic field from the STM tip allows us to further characterize and engineer the quantum states. These results open a new avenue to designing and exploring quantum magnets at the atomic scale for applications in spintronics and quantum simulations.

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