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

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.

1992 ◽  
Vol 270 ◽  
Author(s):  
Mark R. Pederson ◽  
Warren E. Pickett

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.


MRS Bulletin ◽  
1998 ◽  
Vol 23 (9) ◽  
pp. 32-35 ◽  
Author(s):  
Dieter M. Gruen

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.


1998 ◽  
Vol 527 ◽  
Author(s):  
Armando Netto ◽  
Michael Frenklach

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.


1994 ◽  
Vol 9 (6) ◽  
pp. 1546-1551 ◽  
Author(s):  
Darin S. Olson ◽  
Michael A. Kelly ◽  
Sanjiv Kapoor ◽  
Stig B. Hagstrom

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.


2001 ◽  
Vol 08 (03n04) ◽  
pp. 347-351 ◽  
Author(s):  
M. CATTANI ◽  
M. C. SALVADORI

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.


2004 ◽  
Vol 14 (12) ◽  
pp. 835-839 ◽  
Author(s):  
Kwon-Jai Lee ◽  
Jae-Soo Shin ◽  
Ki-Hong Kwon ◽  
Min-Soo Lee ◽  
Jae-Gui Koh

2014 ◽  
Vol 1027 ◽  
pp. 163-166
Author(s):  
Bo Song ◽  
Bin Shen ◽  
Xue Lin Lei ◽  
Lei Cheng ◽  
Fang Hong Sun

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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