A mechanism of CVD diamond film growth deduced from the sequential deposition from sputtered carbon and atomic hydrogen

1994 ◽  
Vol 9 (6) ◽  
pp. 1546-1551 ◽  
Author(s):  
Darin S. Olson ◽  
Michael A. Kelly ◽  
Sanjiv Kapoor ◽  
Stig B. Hagstrom
Keyword(s):  
Growth Mechanism ◽  
Atomic Hydrogen ◽  
Film Growth ◽  
Deposition Process ◽  
Cvd Diamond ◽  
Surface Growth ◽  
Diamond Surface ◽  
Hydrogen Flux ◽  
Sequential Deposition ◽  
Disordered Carbon

We describe a growth mechanism of CVD diamond films consisting of a series of surface reactions. It is derived from experimental observations of a sequential deposition process in which incident carbon flux and atomic hydrogen flux were independently varied. In this sequential process, film growth rate increased with atomic hydrogen exposure, and a saturation in the utilization of carbon was observed. These features are consistent with a surface growth process consisting of the following steps: (i) the carburization of the diamond surface, (ii) the deposition of highly disordered carbon on top of this surface, (iii) the etching of disordered carbon by atomic hydrogen, (iv) the conversion of the carburized diamond surface to diamond at growth sites by atomic hydrogen, and (v) the carburization of newly grown diamond surface. The nature of the growth sites on the diamond surface has not been determined experimentally, and the existence of the carburized surface layer has not been demonstrated experimentally. The surface growth mechanism is the only one consistent with the growth observed in conventional diamond reactors and the sequential reactor, while precluding the necessity of gas phase precursors.

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.

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.

scholarly journals New ultrahigh vacuum setup and advanced diagnostic techniques for studying a-Si:H film growth by radical beams

2004 ◽  
Vol 808 ◽  
Author(s):  
J.P.M. Hoefnagels ◽  
E. Langereis ◽  
M.C.M. van de Sanden ◽  
W.M.M. Kessels
Keyword(s):  
Real Time ◽  
Surface Science ◽  
Spectroscopic Ellipsometry ◽  
Atomic Hydrogen ◽  
Film Growth ◽  
Ultrahigh Vacuum ◽  
Deposition Process ◽  
Diagnostic Techniques ◽  
Hot Wire ◽  
Optical Diagnostic

ABSTRACTA new ultrahigh vacuum setup is presented which is designed for studying the surface science aspects of a-Si:H film growth using various advanced optical diagnostic techniques. The setup is equipped with plasma and radical sources which produce well-defined radicals beams such that the a-Si:H deposition process can be mimicked. In this paper the initial experiments with respect to deposition of a-Si:H using a hot wire source and etching of a-Si:H by atomic hydrogen are presented. These processes are monitored by real time spectroscopic ellipsometry and the etch yield of Si by atomic hydrogen is quantified to be 0.005±0.002 Si atoms per incoming H atom.

Simulation of CVD Diamond Film Growth by Method of Revised KMC

2014 ◽  
Vol 989-994 ◽  
pp. 168-171
Author(s):  
Li Zhu Zhang ◽  
Fu Zhong Wang
Keyword(s):  
Diamond Film ◽  
Atomic Hydrogen ◽  
Film Growth ◽  
Cvd Diamond ◽  
Film Deposition ◽  
Radical Concentration ◽  
Film Deposition Rate ◽  
Cvd Diamond Film ◽  
Diamond Film Growth ◽  
Good Agreement

The growth of CVD diamond film was simulated by using revised KMC method. The simulation was conducted at CH3 radical concentration (0.01%-0.03%) and atomic hydrogen concentration (0.01%-0.5%). The results showed that: The CVD diamond film growth under revised KMC method is superior, which is in good agreement with the experimental results. The concentration of CH3 ([CH3]) and the concentration of atomic H ([H]) can produce important effects on the film deposition rate, surface roughness and the concentration of atom H embedded in the film.

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.

Hard Carbon Films with Various Microstructure Prepared by Ion Assisted Evaporation

1993 ◽  
Vol 316 ◽  
Author(s):  
J. Ullmann ◽  
A. Weber ◽  
U. Falke
Keyword(s):  
Growth Mechanism ◽  
Film Growth ◽  
Carbon Films ◽  
Carbon Surface ◽  
Vickers Indentation ◽  
Structure Modification ◽  
Hard Carbon ◽  
Ion Etching ◽  
Ion Energy ◽  
Free Ion

ABSTRACTFor a deeper understanding of the creation of carbon films the hydrogen-free ion assisted evaporation (IAE) method with neon species was used. Variation of the ion parameters energy and ion to neutral arrival ratio, delivering the necessary energy for modification of the film growth, results in different microstructures investigated with EELS, HRTEM and TED as well as different microhardnesses measured by dynamical Vickers indentation. A possible film growth mechanism is proposed based on an ion etching of mainly sp2-bonded carbon surface atoms and on defect dominated structure modification below the surface depending on the ion energy

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