Molecular dynamics simulation of aluminum nitride deposition: temperature and N : Al ratio effects

Heteroepitaxial growth of aluminum nitride (AIN) has been explored by experiments, but the corresponding growth mechanism is still unrevealed. Here, we use molecular dynamics simulations to study effects of temperature and N : Al flux ratio on deposited AlN. When the temperature increases from 1000 K to 2000 K with an N : Al flux ratio of 2.0, the growth rate of the AlN film decreases. The crystallinity of the deposited AlN is distinctly improved as the temperature increases from 1000 K to 1800 K and it becomes saturated between 1800 K and 2000 K. The crystallinity of the deposited film at 1800 K increases with an increase in the N : Al flux ratio from 0.8 to 2.4, and this degraded a little at an N : Al flux ratio of 2.8. In addition, stoichiometry is closely related to crystallinity of deposited films. Film with good crystallinity is connected with a near 50% N fraction. Furthermore, the average mean biaxial stress and mean normal stress at 1800 K with N : Al flux ratios of 2.0, 2.4 and 2.8 are calculated, indicating that the deposited film with lowest stress has the best crystal quality and the defects appear where stresses occur.

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Molecular Dynamics Simulation of AlN Deposition: Effect of N:Al Flux Ratio

ASME 2018 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems ◽

10.1115/ipack2018-8315 ◽

2018 ◽

Author(s):

Libin Zhang ◽

Guo Zhu ◽

Kuan Sun ◽

Zhiyin Gan ◽

Xiaobing Luo

Keyword(s):

Molecular Dynamics ◽

Surface Roughness ◽

Molecular Dynamics Simulation ◽

Uniform Distribution ◽

Growth Temperature ◽

Flux Ratio ◽

Dynamics Simulation ◽

Good Crystallinity ◽

Temperature Ranges ◽

Deposition Effect

In order to study the optimal N:Al flux ratio during the deposition of AlN, the effects of N:Al flux ratio on the crystal quality (crystallinity and surface roughness) of homoepitaxial AlN are investigated. The growth temperature ranges from 1600 K to 2000 K with an increment of 200 K. When the N:Al flux ratios are changed from 0.8 to 2.8, the good crystallinity is obtained at 1600 K with the N:Al flux ratio of 2.4, while it is obtained at 1800 K with the N:Al flux ratio of 2.4 and with the N:Al flux ratio of 2.0 at 2000 K. The crystallinity at 1800 K with N:Al flux ratio of 2.4 stands out among these three. At 1800 K with varied N:Al flux ratios, the minimum surface roughness is also obtained at the N:Al flux ratio of 2.4. Further more, the distribution of deposited Al atoms at 1800 K is explored, the result shows that the uniform distribution of Al atoms appears at N:Al flux ratio of 2.4.

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Multicanonical Molecular Dynamics Simulation Study of the Liquid-Solid and Solid-Solid Transitions in Lennard-Jones Clusters

ASME/JSME 2011 8th Thermal Engineering Joint Conference ◽

10.1115/ajtec2011-44457 ◽

2011 ◽

Author(s):

Toshihiro Kaneko ◽

Kenji Yasuoka ◽

Ayori Mitsutake ◽

Xiao Cheng Zeng

Keyword(s):

Molecular Dynamics ◽

Heat Capacity ◽

Transition Temperature ◽

Peak Position ◽

Temperature Curve ◽

Dynamics Simulation ◽

Lennard Jones ◽

Dynamics Simulations ◽

First Time ◽

Good Agreement

Multicanonical molecular dynamics simulations are applied, for the first time, to study the liquid-solid and solid-solid transitions in Lennard-Jones (LJ) clusters. The transition temperatures are estimated based on the peak position in the heat capacity versus temperature curve. For LJ31, LJ58 and LJ98, our results on the solid-solid transition temperature are in good agreement with previous ones. For LJ309, the predicted liquid-solid transition temperature is also in agreement with previous result.

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Reactive molecular dynamics simulation of the high-temperature pyrolysis of 2,2′,2′′,4,4′,4′′,6,6′,6′′-nonanitro-1,1′:3′,1′′-terphenyl (NONA)

RSC Advances ◽

10.1039/c9ra10261b ◽

2020 ◽

Vol 10 (9) ◽

pp. 5507-5515

Author(s):

Liang Song ◽

Feng-Qi Zhao ◽

Si-Yu Xu ◽

Xue-Hai Ju

Keyword(s):

Molecular Dynamics ◽

High Temperature ◽

Molecular Dynamics Simulation ◽

Molecular Dynamics Simulations ◽

Dynamics Simulation ◽

Reactive Molecular Dynamics ◽

Ring Compounds ◽

Fused Ring ◽

Dynamics Simulations

The bimolecular and fused ring compounds are found in the high-temperature pyrolysis of NONA using ReaxFF molecular dynamics simulations.

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Heteroepitaxial Growth of 3C-SiC on Si (111) Substrate Using AlN as a Buffer Layer

Materials Science Forum ◽

10.4028/www.scientific.net/msf.600-603.251 ◽

2008 ◽

Vol 600-603 ◽

pp. 251-254 ◽

Cited By ~ 1

Author(s):

Yong Mei Zhao ◽

Guo Sheng Sun ◽

Xing Fang Liu ◽

Jia Ye Li ◽

Wan Shun Zhao ◽

...

Keyword(s):

Buffer Layer ◽

Chemical Vapor ◽

Heteroepitaxial Growth ◽

Si Substrate ◽

Si Substrates ◽

Good Crystallinity ◽

Aln Film ◽

Pressure Chemical ◽

Aln Buffer ◽

Sic Film

Using AlN as a buffer layer, 3C-SiC film has been grown on Si substrate by low pressure chemical vapor deposition (LPCVD). Firstly growth of AlN thin films on Si substrates under varied V/III ratios at 1100oC was investigated and the (002) preferred orientational growth with good crystallinity was obtained at the V/III ratio of 10000. Annealing at 1300oC indicated the surface morphology and crystallinity stability of AlN film. Secondly the 3C-SiC film was grown on Si substrate with AlN buffer layer. Compared to that without AlN buffer layer, the crystal quality of the 3C-SiC film was improved on the AlN/Si substrate, characterized by X-ray diffraction (XRD) and Raman measurements.

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Molecular Dynamics Simulation Study of Lecithin Inhibiting Hydrate-Dissociation

Materials Science Forum ◽

10.4028/www.scientific.net/msf.890.252 ◽

2017 ◽

Vol 890 ◽

pp. 252-259

Author(s):

Le Wang ◽

Guan Cheng Jiang ◽

Xin Lin ◽

Xian Min Zhang ◽

Qi Hui Jiang

Keyword(s):

Molecular Dynamics ◽

Water Movement ◽

Simulation Analysis ◽

Mass Density ◽

Dynamics Simulation ◽

Dissociation Process ◽

Hydrate Dissociation ◽

Hydrocarbon Chains ◽

Dynamics Simulations ◽

Mass Density Profile

Molecular dynamics simulations are used to study the dissociation inhibiting mechanism of lecithin for structure I hydrates. Adsorption characteristics of lecithin and PVP (poly (N-vinylpyrrolidine)) on the hydrate surfaces were performed in the NVT ensemble at temperatures of 277K and the hydrate dissociation process were simulated in the NPT ensemble at same temperature. The results show that hydrate surfaces with lecithin is more stable than the ones with PVP for the lower potential energy. The conformation of lecithin changes constantly after the balanced state is reached while the PVP molecular dose not. Lecithin molecule has interaction with lecithin nearby and hydrocarbon-chains of lecithin molecules will form a network to prevent the diffusion of water and methane molecules, which will narrow the available space for hydrate methane and water movement. Compared with PVP-hydrate simulation, analysis results (snapshots and mass density profile) of the dissociation simulations show that lecithin-hydrate dissociates more slowly.

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Molecular Dynamics Simulations of High Energy Cascades in Iron

MRS Proceedings ◽

10.1557/proc-373-21 ◽

1994 ◽

Vol 373 ◽

Cited By ~ 9

Author(s):

Roger E. Stoller

Keyword(s):

Molecular Dynamics ◽

Three Dimensional ◽

High Energy ◽

Dynamics Simulation ◽

Method Of Molecular Dynamics ◽

Energy Cascades ◽

Iron Based ◽

The Many ◽

Property Changes ◽

Dynamics Simulations

AbstractA series of high-energy, up to 20 keV, displacement cascades in iron have been investigated for times up to 200 ps at 100 K using the method of molecular dynamics simulation. Thesimulations were carried out using the MOLDY code and a modified version of the many-bodyinteratomic potential developed by Finnis and Sinclair. The paper focuses on those results obtained at the highest energies, 10 and 20 keV. The results indicate that the fraction of the Frenkel pairs surviving in-cascade recombination remains fairly high in iron and that the fraction of the surviving point defects that cluster is lower than in materials such as copper. In particular, vacancy clustering appears to be inhibited in iron. Some of the interstitial clusters were observed to exhibit an unexpectedly complex, three-dimensional morphology. The observations are discussed in terms of their relevance to microstructural evolution and mechanical property changes in irradiated iron-based alloys.

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Molecular Dynamics Simulation of Sputtering with Mmany-Body Interactions

MRS Proceedings ◽

10.1557/proc-100-145 ◽

1988 ◽

Vol 100 ◽

Author(s):

Davy Y. Lo ◽

Tom A. Tombrello ◽

Mark H. Shapiro ◽

Don E. Harrison

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulation ◽

Single Crystal ◽

Low Energy ◽

Dynamics Simulation ◽

Embedded Atom Method ◽

Many Body ◽

Embedded Atom ◽

Dynamics Simulations ◽

Small Single Crystal

ABSTRACTMany-body forces obtained by the Embedded-Atom Method (EAM) [41 are incorporated into the description of low energy collisions and surface ejection processes in molecular dynamics simulations of sputtering from metal targets. Bombardments of small, single crystal Cu targets (400–500 atoms) in three different orientations ({100}, {110}, {111}) by 5 keV Ar+ ions have been simulated. The results are compared to simulations using purely pair-wise additive interactions. Significant differences in the spectra of ejected atoms are found.

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Molecular Dynamics Simulation of Wetting Behavior: Contact Angle Dependency on Water Potential Models

ICS Physical Chemistry ◽

10.34311/icspc.2021.1.1.10 ◽

2021 ◽

Vol 1 (1) ◽

pp. 10

Author(s):

Lukman Hakim ◽

Irsandi Dwi Oka Kurniawan ◽

Ellya Indahyanti ◽

Irwansyah Putra Pradana

Keyword(s):

Molecular Dynamics ◽

Contact Angle ◽

Liquid Droplet ◽

Center Of Mass ◽

Contact Angles ◽

Surface Wettability ◽

Dynamics Simulation ◽

Potential Models ◽

Surface Hydrophilicity ◽

Dynamics Simulations

The underlying principle of surface wettability has obtained great attentions for the development of novel functional surfaces. Molecular dynamics simulations has been widely utilized to obtain molecular-level details of surface wettability that is commonly quantified in term of contact angle of a liquid droplet on the surface. In this work, the sensitivity of contact angle calculation at various degrees of surface hydrophilicity to the adopted potential models of water: SPC/E, TIP4P, and TIP5P, is investigated. The simulation cell consists of a water droplet on a structureless surface whose hydrophilicity is modified by introducing a scaling factor to the water-surface interaction parameter. The simulation shows that the differences in contact angle described by the potential models are systematic and become more visible with the increase of the surface hydrophilicity. An alternative method to compute a contact angle based on the height of center-of-mass of the droplet is also evaluated, and the resulting contact angles are generally larger than those determined from the liquid-gas interfacial line.

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