scholarly journals Atomic-Level Investigation ofCHxandC2HxAdsorption onβ-SiC (111) Surface for CVD Diamond Growth from DFT Calculations

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Naichao Chen ◽  
Fanghong Sun
Keyword(s):  
Density Functional ◽  
Hydrogen Adsorption ◽  
Film Growth ◽  
Cvd Diamond ◽  
Unsaturated Hydrocarbon ◽  
Atomic Scale ◽  
Diamond Growth ◽  
Diamond Coatings ◽  
Surface Reconstructions ◽  
Diamond Film Growth

The focus of this paper is on the adsorption of unsaturated hydrocarbon molecules onβ-SiC (111) surfaces during diamond film growth. TheCHxandC2Hxmolecules have been investigated to obtain a specific insight into absorbing diamond processes on the atomic scale. Structural and electronic properties ofCHxandC2Hxadsorption on the Si- and C-terminated surfaces have been studied by first-principles calculations based on density functional theory (DFT). From the calculated energetics and geometries, we find thatC2Hxadsorption on the Si-terminated surfaces has six possible surface reconstructions. For the C-terminated surface, there exist eight possible surface reconstructions. Five surface reconstructions, includingCH2adsorption on the Si- and C-terminated surface, CH–CH2and CH=CH2adsorption on the C-terminated surface, andC2H5adsorption on the Si-terminated surface, have the largest hydrogen adsorption energies and more stability of surface reconstructions. Calculations demonstrate that the Si-terminated surface is energetically more favorable for fabricating CVD diamond coatings than the C-terminated surface.

scholarly journals Effect of Nitrogen on the Growth of (100)-, (110)-, and (111)-Oriented Diamond Films

2020 ◽  
Vol 11 (1) ◽  
pp. 126
Author(s):  
Jen-Chuan Tung ◽  
Tsung-Che Li ◽  
Yen-Jui Teseng ◽  
Po-Liang Liu
Keyword(s):  
Growth Mechanism ◽  
Density Functional ◽  
Film Growth ◽  
Hydrogen Abstraction ◽  
Diamond Films ◽  
Activation Energies ◽  
Diamond Surface ◽  
Nitrogen Doped ◽  
Nitrogen Substitution ◽  
Diamond Film Growth

The aim of this research is the study of hydrogen abstraction reactions and methyl adsorption reactions on the surfaces of (100), (110), and (111) oriented nitrogen-doped diamond through first-principles density-functional calculations. The three steps of the growth mechanism for diamond thin films are hydrogen abstraction from the diamond surface, methyl adsorption on the diamond surface, and hydrogen abstraction from the methylated diamond surface. The activation energies for hydrogen abstraction from the surface of nitrogen-undoped and nitrogen-doped diamond (111) films were −0.64 and −2.95 eV, respectively. The results revealed that nitrogen substitution was beneficial for hydrogen abstraction and the subsequent adsorption of methyl molecules on the diamond (111) surface. The adsorption energy for methyl molecules on the diamond surface was generated during the growth of (100)-, (110)-, and (111)-oriented diamond films. Compared with nitrogen-doped diamond (100) films, adsorption energies for methyl molecule adsorption were by 0.14 and 0.69 eV higher for diamond (111) and (110) films, respectively. Moreover, compared with methylated diamond (100), the activation energies for hydrogen abstraction were by 0.36 and 1.25 eV higher from the surfaces of diamond (111) and (110), respectively. Growth mechanism simulations confirmed that nitrogen-doped diamond (100) films were preferred, which was in agreement with the experimental and theoretical observations of diamond film growth.

Theoretical Investigation of Fluorinated and Hydrocenated Diamond Filks

1992 ◽  
Vol 270 ◽  
Author(s):  
Mark R. Pederson ◽  
Warren E. Pickett
Keyword(s):  
Density Functional ◽  
Film Growth ◽  
Growth Models ◽  
Diamond Films ◽  
Diamond Surface ◽  
Free Standing ◽  
Level Shifts ◽  
Reconstructed Surface ◽  
Experimental Values ◽  
Diamond Film Growth

ABSTRACTTo investigate some of the fundamental differences between halogen and hydrogen assisted diamond film growth we have performed several calculations related to the <100> diamond surface. The models used in these investigations include ten-layer periodic slabs of free standing fluorinated diamond films as well as isolated clusters [C21F6H20]. For purposes of comparison, we have also performed calculations on models of the hydrogenated <100> surface. The calculations are performed within the density-functional framework using LCAO and LAPW computational methods. We have considered two geometries of a monofluoride surface. The first surface, best described as an ideal l×l surface with a monolayer of ionically bonded fluorines, exhibits a metallic density of states in contrast to a 2×l reconstructed surface with chemically bonded fluorines that is found to be insulating. We compare theoretical carbon core level shifts with experimental values and discuss growth models based on these surface calculations.

Fracture of Thin Synthetic Diamond Films

1996 ◽  
Vol 436 ◽  
Author(s):  
M. D. Drory
Keyword(s):  
Synthetic Diamond ◽  
Steel Substrate ◽  
Diamond Films ◽  
Cvd Diamond ◽  
Diamond Growth ◽  
Steel Alloy ◽  
Diamond Coating ◽  
Diamond Coatings ◽  
Growth Environment ◽  
Substrate Hardness

AbstractLarge residual stresses in diamond coatings may result in film failure through splitting, delamination and substrate failure. In addition, the CVD diamond growth environment may degrade the substrate mechanical properties. These issues are examined for diamond-coating of a tool steel alloy. Diamond growth was achieved on the steel substrate with the use of a titanium interlayer. Embrittlement of the Ti interlayer was not evident, however the substrate hardness was severely degraded.

Boron incorporation effects in CVD diamond film growth

Vacuum ◽  
1994 ◽  
Vol 45 (10-11) ◽  
pp. 1013-1014 ◽  
Author(s):  
MC Polo ◽  
J Cifre ◽  
J Esteve
Keyword(s):  
Diamond Film ◽  
Film Growth ◽  
Cvd Diamond ◽  
Cvd Diamond Film ◽  
Diamond Film Growth

Nanodiamond Injection into the Gas-Phase During CVD Diamond Film Growth

2005 ◽  
pp. 145-156 ◽  
Author(s):  
N.A. Feoktistov ◽  
V.G. Golubev ◽  
S.A. Grudinkin ◽  
A.V. Nashchekin ◽  
T.S. Perova ◽  
...  
Keyword(s):  
Gas Phase ◽  
Diamond Film ◽  
Film Growth ◽  
Cvd Diamond ◽  
Cvd Diamond Film ◽  
Diamond Film Growth

Simulations of CVD Diamond Film Growth Using a Simplified Monte Carlo Model

2009 ◽  
Vol 1203 ◽  
Author(s):  
Paul William May ◽  
Jeremy N. Harvey ◽  
Neil L. Allan ◽  
James C. Richley ◽  
Yuri A. Mankelevich
Keyword(s):  
Monte Carlo ◽  
Vapour Deposition ◽  
Film Growth ◽  
Monte Carlo Model ◽  
Chemical Vapour ◽  
Cvd Diamond ◽  
Surface Migration ◽  
Average Diffusion ◽  
Cvd Diamond Film ◽  
Diamond Film Growth

AbstractA simple 1-dimensional Monte Carlo (KMC) model has been developed to simulate the chemical vapour deposition (CVD) of a diamond (100) surface. The model considers adsorption, etching/desorption, lattice incorporation, and surface migration along and across the dimer rows. The reaction probabilities for these processes are re-evaluated in detail and their effects upon the predicted growth rates and morphology are described. We find that for standard CVD diamond conditions, etching of carbon species from the growing surface is negligible. Surface migration occurs rapidly, but is mostly limited to CH2 species oscillating rapidly back and forth between two adjacent radical sites. Despite the average number of migration hops being in the thousands, the average diffusion length for a surface species is <2 sites.

DIAMOND DEPOSITION ON WC/Co ALLOY WITH A MOLYBDENUM INTERMEDIATE LAYER

2005 ◽  
Vol 12 (04) ◽  
pp. 499-504
Author(s):  
SHA LIU ◽  
ZHI-MING YU ◽  
DAN-QING YI
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Intermediate Layer ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Diamond Growth ◽  
Diamond Coatings ◽  
Sputter Deposited ◽  
Diamond Grain

It is known that in the condition of chemical vapor deposition (CVD) diamond process, molybdenum is capable of forming carbide known as the "glue" which promotes growth of the CVD diamond, and aids its adhesion by (partial) relief of stresses at the interface. Furthermore, the WC grains are reaction bonded to the Mo 2 C phase. Therefore, molybdenum is a good candidate material for the intermediate layer between WC–Co substrates and diamond coatings. A molybdenum intermediate layer of 1–3 μm thickness was magnetron sputter-deposited on WC/Co alloy prior to the deposition of diamond coatings. Diamond films were deposited by hot filament chemical vapor deposition (HFCVD). The chemical quality, morphology, and crystal structure of the molybdenum intermediate layer and the diamond coatings were characterized by means of SEM, EDX, XRD and Raman spectroscopy. It was found that the continuous Mo intermediate layer emerged in spherical shapes and had grain sizes of 0.5–1.5 μm after 30 min sputter deposition. The diamond grain growth rate was slightly slower as compared with that of uncoated Mo layer on the WC–Co substrate. The morphologies of the diamond films on the WC–Co substrate varied with the amount of Mo and Co on the substrate. The Mo intermediate layer was effective to act as a buffer layer for both Co diffusion and diamond growth.

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