Activation energies for the growth of diamond films and the renucleation of diamond grains during film growth

2014 ◽  
Vol 32 (3) ◽  
pp. 031808 ◽  
Author(s):  
Divani Carvalho Barbosa ◽  
Mauricio Ribeiro Baldan ◽  
Vladimir Jesus Trava-Airoldi ◽  
Evaldo Jose Corat
Keyword(s):  
Film Growth ◽  
Diamond Films ◽  
Activation Energies

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.

Kinetic Monte Carlo Simulation of Diamond Film Growth with the Inclusion of Surface Migration

1998 ◽  
Vol 527 ◽  
Author(s):  
Armando Netto ◽  
Michael Frenklach
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Film Growth ◽  
Kinetic Monte Carlo ◽  
Diamond Films ◽  
State Theory ◽  
Diamond Surface ◽  
Diamond Growth ◽  
Gaseous Species ◽  
Surface Migration

ABSTRACTDiamond films are of interest in many practical applications but the technology of producing high-quality, low-cost diamond is still lacking. To reach this goal, it is necessary to understand the mechanism underlying diamond deposition. Most reaction models advanced thus far do not consider surface diffusion, but recent theoretical results, founded on quantum-mechanical calculations and localized kinetic analysis, highlight the critical role that surface migration may play in growth of diamond films. In this paper we report a three-dimensional time-dependent Monte Carlo simulations of diamond growth which consider adsorption, desorption, lattice incorporation, and surface migration. The reaction mechanism includes seven gas-surface, four surface migration, and two surface-only reaction steps. The reaction probabilities are founded on the results of quantum-chemical and transition-state-theory calculations. The kinetic Monte Carlo simulations show that, starting with an ideal {100}-(2×1) reconstructed diamond surface, the model is able to produce a continuous film growth. The smoothness of the growing film and the developing morphology are shown to be influenced by rate parameter values and by deposition conditions such as temperature and gaseous species concentrations.

Diamond Films: Recent Developments in Theory and Practice

MRS Bulletin ◽  
1998 ◽  
Vol 23 (9) ◽  
pp. 28-31 ◽  
Author(s):  
A.M. Stoneham ◽  
I.J. Ford ◽  
P.R. Chalker
Keyword(s):  
Film Growth ◽  
Defect Density ◽  
Diamond Films ◽  
Electrical Contacts ◽  
Film Deposition ◽  
Theory And Practice ◽  
Maximum Effect ◽  
Recent Developments ◽  
Improved Performance ◽  
The Many

The diamond films of the early 1980s presented two quite different challenges. First how could this new form of diamond be exploited technically? Second, how could this clearly nonequilibrium generation of diamond be understood and the understanding be used to maximum effect? We shall be discussing the ideas of theory and modeling, and we will show how they have contributed to the interplay of science and technology.The science of diamond films is the art of beating nature in the use of carbon. Theory gives the understanding to improve this art. One way in which we improve on nature is in new geometries: controlled growth over selected surfaces o surface regions. The coverage, defect density, microstructure, and rate of growth are key issues. Another way to beat nature is controlled doping. Could wmake n-type semiconductors or lasers using diamond films? A third direction might be routes to control interfaces. Grai boundaries and the regions between small, misaligned crystals affect thermal properties and electron emission. Difficulties with electrical contacts may limit the use of diamond films as semiconductors or insulators. Substrate-film adhesion can determine tribological performance.If theory is to play a role in controlling film deposition, we need to understand the role of theory itself. Theory can add value at several distinct levels. At the highest level, modeling has the potential to provide a substitute for experiment, especially when information is needed about behavior at extreme conditions. When the phenomena are very fast or very complex, theory can be used to interpret limited experiments. At a more modest level, even simple quantitative models can illustrate the many processes occurring during film growth. Atomistic theories of this type can identify the rate-determining steps and point to ways of influencing them. Mesoscopic theories, especially combined with macroscopic approaches like elasticity theory, can identify routes to improved performance.

Attempts to p-Dope Ultrananocrystalline Diamond Films in a Hot Filament Reactor

2006 ◽  
Vol 956 ◽  
Author(s):  
Paul William May ◽  
Matthew Hannaway
Keyword(s):  
Vapour Deposition ◽  
Film Growth ◽  
Substrate Surface ◽  
Diamond Films ◽  
Chemical Vapour ◽  
Grain Sizes ◽  
Ultrananocrystalline Diamond ◽  
The Individual ◽  
P Type ◽  
Hot Filament

ABSTRACTUltrananocrystalline diamond (UNCD) films have been deposited using hot filament chemical vapour deposition using Ar/CH4/H2 gas mixtures plus additions of B2H6 in an attempt to make p-type semiconducting films. With increasing additions of B2H6 from 0 to 40,000 ppm with respect to C, the film growth rate was found to decrease substantially, whilst the individual grain sizes increased from nm to μm. With 40,000 ppm of B2H6, crystals of boric oxide were found on the substrate surface, which slowly hydrolysed to boric acid on exposure to air. These results are rationalised using a model for UNCD growth based on competition for surface radical sites between CH3 and C atoms.

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.

DYNAMIC SCALING PHENOMENA IN DIAMOND FILM GROWTH

2001 ◽  
Vol 08 (03n04) ◽  
pp. 347-351 ◽  
Author(s):  
M. CATTANI ◽  
M. C. SALVADORI
Keyword(s):  
Chemical Vapor Deposition ◽  
Differential Equations ◽  
Diamond Film ◽  
Vapor Deposition ◽  
Film Growth ◽  
Diamond Films ◽  
Growth Dynamics ◽  
Chemical Vapor ◽  
Dynamic Scaling ◽  
Diamond Film Growth

In this paper we investigate how the growth dynamics of diamond films, synthesized by plasma-enhanced chemical vapor deposition, can be explained within the framework of the Edwards–Wilkinson and Kardar–Parisi–Zhang stochastic differential equations.

Nucleation, Growth, and Microstructure of Nanocrystalline Diamond Films

MRS Bulletin ◽  
1998 ◽  
Vol 23 (9) ◽  
pp. 32-35 ◽  
Author(s):  
Dieter M. Gruen
Keyword(s):  
Atomic Hydrogen ◽  
Film Growth ◽  
Hydrogen Abstraction ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Decisive Role ◽  
Theoretical Work ◽  
Diamond Lattice ◽  
Diamond Surface ◽  
Methyl Radical

It has been generally believed that hydrogen plays a central role in the various processes that have been developed over the years for the chemical vapor deposition (CVD) of diamond films. In particular it has been thought that atomic hydrogen is an absolutely essential ingredient of the vapor from which the films are grown. Typically in diamond CVD, gas mixtures consisting of l-vol% CH3 in 99-vol% H2 have been used in which atomic hydrogen is generated either by thermal decomposition or by collisional processes in a plasma. With a hydrocarbon precursor such as CH3, gas-phase hydrogen-abstraction reactions lead to the generation of the methyl radical CH3, which adsorbs on a carbon radical site also created by hydrogen abstraction from the hydrogen-terminated growing diamond surface. Additional hydrogen-abstraction reactions allow the carbon in the adsorbed methyl radical to form carbon-carbon bonds and thus be incorporated into the diamond lattice. Because graphite is thermodynamically more stable than diamond, the growth of metastable diamond has been thought to require the presence of atomic hydrogen, which has been said to stabilize the diamond lattice and to remove graphitic nuclei when they do form because of the preferential etching or regasification of graphite over diamond. This description of diamond-film growth from hydrocarbon–hydrogen mixtures is of course a very highly condensed version of the detailed experimental and theoretical work that has been carried out in the field over the years. However the predominant conclusion of most of that work is that, particularly in the absence of oxygen and perhaps halogens, atomic hydrogen plays a crucial and decisive role in diamond CVD.

Simulation of Temperature Distribution in HFCVD Diamond Films Growth on the Multitudinous Micro End Mills

2014 ◽  
Vol 1027 ◽  
pp. 163-166
Author(s):  
Bo Song ◽  
Bin Shen ◽  
Xue Lin Lei ◽  
Lei Cheng ◽  
Fang Hong Sun
Keyword(s):  
Temperature Distribution ◽  
Film Growth ◽  
Diamond Films ◽  
Filament Length ◽  
Substrate Distance ◽  
Filament Diameter ◽  
End Mills ◽  
Best Parameter ◽  
Diamond Film Growth

In the process of HFCVD diamond film growth on the multitudinous micro end mills, the uniformity and stability of the temperature distribution have a vital importance on the quality of film. So a new method by using the finite volume is proposed to analyze the importance of different disposition parameters on the uniformity of substrate temperature field. These parameters are filament diameter (d), filament-substrate distance (H), filament separation (S) and filament length (L). The mono-factor method are used to optimize the best parameter combination. The simulation results show that the optimized parameters are d=0.65mm, H=10mm, S=27mm and L=160mm.

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