Influence of nitrogen on diamond growth in oxyacetylene combustion chemical vapor deposition

Abstract

Document VersionPublisher's PDF, also known as Version of Record (includes final page, issue and volume numbers) Please check the document version of this publication:• A submitted manuscript is the author's version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website.• The final author version and the galley proof are versions of the publication after peer review.• The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Addition of di-nitrogen to the feed gas has been shown to greatly influence growth rates and morphology of the deposited layer in various diamond chemical vapor deposition ͑CVD͒ techniques. In this article, several hypotheses for these phenomena, as presented in literature, are tested for the case of diamond combustion CVD with the aid of an atmospheric pressure oxyacetylene flame. For this purpose, one-dimensional and two-dimensional simulations are performed of the hydrodynamics, the combustion and deposition chemistry, and the nitrogen chemistry. Based on the simulation results, several proposed hypotheses can be ruled out as possible explanations for the observed phenomena. It is concluded, that the most likely hypotheses are: ͑i͒ the presence of nitrogen atoms in the diamond lattice, enhancing diamond growth by acting on the electron structure of surface dimer bonds, and ͑ii͒ selective adsorption of nitrogen-containing species on the surface, selectively increasing growth in the ͑100͒ direction. It is found that possible gas phase candidates for affecting diamond growth are NH, NH 2 , NH 3 , CN, HCN, H 2 CN, and NCO.

Multi-scale modeling of chemical vapor deposition processes for thin film technology

“…comparison between model predictions and experimental data for the film growth as a function of surface temperature. With the described model, it was possible to explain and predict the non-uniformity in thickness and quality of the deposited diamond film [162,163].…”

“…Okkerse and coworkers [30,162,163] constructed a twodimensional axi-symmetric model of the process, based on the simultaneous simulation of (i) the multi-reaction combustion chemistry in the flame, (ii) the multi-reaction deposition chemistry at the surface, and (iii) the multicomponent transport phenomena.…”

Influence of nitrogen addition on oxyacetylene flame chemical vapor deposition of diamond as studied by solid state techniques and gas phase diagnostics

“…For its incorporation it is necessary that nitrogen is transferred from the gas phase to the growing diamond surface by one or more reactive nitrogencontaining species. Okkerse et al [17][18][19] performed two-dimensional numerical simulations of oxyacetylene flame deposition with the addition of nitrogen, and used the necessary presence of off-axis maxima in the concentration profile to select the nitrogencontaining species that may be of direct importance for the influence of nitrogen addition on diamond growth. Nitrogen from the air enters the flame and interacts with it to form nitrogen-containing species.…”

“…A very useful deposition technique for obtaining insight into the mechanisms of nitrogen influence on diamond CVD is oxyacetylene flame deposition in open air. From the list of possible candidates most information with respect to diamond growth is reported on CN 14,15,[17][18][19][20][21][22][23][24] and HCN. 13 As a consequence, the gas phase from which diamond is grown is not homogeneous in radial direction.…”

Modeling of flame assisted chemical vapor deposition of silicon films

“…To lower the computational cost, the two-step solution procedure suggested by others was here adopted for both the 1D and the 2D models: the momentum, energy and mass balances for each species involved in the flame chemistry were first solved and the calculated velocity, pressure, and temperature fields became inputs to precursor species conservation equations, while the consumption of the reacting gas stream (i.e., the deposition rate) was represented by a boundary condition on the reacting areas [10,11].…”