Simulations of CVD Diamond Film Growth: 2D Models for the identities and concentrations of gas-phase species adsorbing on the surface

2011 ◽  
Vol 1282 ◽  
Author(s):  
Paul W. May ◽  
Yuri A. Mankelevich
Keyword(s):  
Gas Phase ◽  
Film Growth ◽  
Microwave Plasma ◽  
Plasma Reactor ◽  
Diamond Films ◽  
Diamond Surface ◽  
Diamond Growth ◽  
Process Conditions ◽  
Ultrananocrystalline Diamond ◽  
Single Crystal Diamond

ABSTRACTA prerequisite for modelling the growth of diamond by CVD is knowledge of the identities and concentrations of the gas-phase species which impact upon the growing diamond surface. Two methods have been devised for the estimation of this information, and have been used to determine adsorption rates for CxHy hydrocarbons for process conditions that experimentally produce single-crystal diamond, microcrystalline diamond films, nanocrystalline diamond films and ultrananocrystalline diamond films. Both methods rely on adapting a previously developed model for the gas-phase chemistry occurring in a hot filament or microwave plasma reactor. Using these methods, the concentrations of most of the CxHy radical species, with the exception of CH3, at the surface have been found to be several orders of magnitude smaller than previously believed. In most cases these low concentrations suggest that reactions such as direct insertion of C1Hy (y = 0-2) and/or C2 into surface C–H or C–C bonds can be neglected and that such species do not contribute significantly to the diamond growth process in the reactors under study.

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.

Single Crystal CVD Diamond growth and characterizations

2006 ◽  
Vol 956 ◽  
Author(s):  
Nicolas Olivier Tranchant ◽  
Dominique Tromson ◽  
Zdenek Remes ◽  
Licinio Rocha ◽  
Milos Nesladek ◽  
...  
Keyword(s):  
Single Crystal ◽  
Microwave Plasma ◽  
Plasma Reactor ◽  
Optical Emission ◽  
Cvd Diamond ◽  
Diamond Growth ◽  
Photocurrent Spectroscopy ◽  
Excited Species ◽  
Single Crystal Diamond

ABSTRACTDue to its radiation harness, single crystal CVD diamond is a remarkable material for the construction of detectors used in hadron physics and for medical therapy. In this work, single crystal CVD diamond plates were grown in a microwave plasma reactor, using home design substrate holder and a relatively high pressure. Optical Emission Spectroscopy was employed during the MW-PECVD growth to characterize excited species present in the plasma and to detect the presence of residual gases such as nitrogen which is unsuitable for detector's applications.The samples were characterized using various methods such as Raman spectroscopy, photoluminescence (PL), photocurrent spectroscopy, Raman mapping, birefringence microscopy, optical microscopy and also AFM. The best sample, exhibits a FWHM for the 1332 cm−1 Raman peak about 1.6 cm−1. Room temperature PL spectra showed no N–related luminescence, confirming the high quality of the grown single crystal diamond.

scholarly journals Simulation-Based Development of a New Cylindrical-Cavity Microwave-Plasma Reactor for Diamond-Film Synthesis

Crystals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 320 ◽  
Author(s):  
Qijun Wang ◽  
Gai Wu ◽  
Sheng Liu ◽  
Zhiyin Gan ◽  
Bo Yang ◽  
...  
Keyword(s):  
Cylindrical Cavity ◽  
Microwave Plasma ◽  
Plasma Reactor ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Optical Microscope ◽  
Plasma Chemical Vapor Deposition ◽  
Atomic Force ◽  
Single Crystal Diamond ◽  
Film Synthesis

A 2.45 GHz microwave-plasma chemical-vapor deposition (MPCVD) reactor was designed and built in-house by collaborating with Guangdong TrueOne Semiconductor Technology Co., Ltd. A cylindrical cavity was designed as the deposition chamber and a circumferential coaxial-mode transformer located at the top of the cavity was adopted as the antenna. Two quartz-ring windows that were placed far away from the plasma and cooled by water-cooling cavity walls were used to affix the antenna to the cavity and act as a vacuum seal for the reactor, respectively. This design improved the sealing and protected the quartz windows. In addition, a numerical simulation was proposed to predict the electric-field and plasma-density distributions in the cavity. Based on the simulation results, a microwave-plasma reactor with TM021 mode was built. The leak rate of this new reactor was tested to be as low as 1 × 10−8 Pa·m3·s−1, and the maximal microwave power was as high as 10 kW. Then, single-crystal diamond films were grown with the morphology and crystalline quality characterized by an optical microscope, atomic force microscope (AFM), Raman spectrometer, photoluminescence (PL) spectrometer, and high-resolution X-ray diffractometer. It was shown that the newly developed MPCVD reactor can produce diamond films with high quality and purity.

Residual Stresses Analysis in Diamond Layers Deposited on Various Substrates

1995 ◽  
Vol 383 ◽  
Author(s):  
D. Rats ◽  
L. Bimbault ◽  
L. Vandenbulcke ◽  
R. Herbin ◽  
K. F. Badawi
Keyword(s):  
Residual Stresses ◽  
Thermal Stresses ◽  
Film Growth ◽  
Microwave Plasma ◽  
Plasma Reactor ◽  
Diamond Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxygen Gas ◽  
Deposition Conditions

ABSTRACTA major problem for diamond coating applications is that diamond films tend to exhibit poor adherence on many. substrates and typically disbond at thicknesses of the order of few micrometers due especially to residual stresses. Residual stresses in diamond are composed of thermal expansion mismatch stresses and intrinsic stresses induced during film growth. Diamond films were deposited in a classical microwave plasma reactor from hydrocarbon-hydrogen-oxygen gas mixtures. Thermal stresses were directly calculated from Hook's law. On silicon substrate, intrinsic stresses were deduced by difference from measurements of total stresses either by the curvature method or by X-ray diffraction using the sin 2ψ method. These investigations allow us to discuss the origin of the intrinsic stresses. The residual stress level was also investigated by Raman spectroscopy as a function of the deposition conditions and substrate materials (SiO2, Si3N4, Si, SiC, WC-Co, Mo and Ti-6A1-4V). We show that the thermal stresses are often preponderant.

An experimental study of the temperature and stoichiometry dependence of diamond growth in low pressure flat flames

1995 ◽  
Vol 10 (1) ◽  
pp. 149-157 ◽  
Author(s):  
J.S. Kim ◽  
M.A. Cappelli
Keyword(s):  
Film Growth ◽  
Diamond Films ◽  
Low Pressure ◽  
Diamond Growth ◽  
Process Conditions ◽  
Optimum Conditions ◽  
First Order ◽  
Flat Flame ◽  
Optimized Conditions ◽  
Substrate Temperatures

A study of the temperature and stoichiometry dependence of diamond synthesis in low pressure premixed acetylene-oxygen flames is presented. A specially designed low pressure flat flame operating at 40 Torr is employed to deposit diamond films uniformly over areas of at least 2 cm2. Under optimized conditions of substrate temperatures and flame equivalence ratios, high quality translucent diamond that is well faceted is synthesized exhibiting first-order Raman fullwidths (half maximum) of about 2.5 cm−1. Diamond growth rates under these optimum conditions are approximately 4 μm/h. The film growth rate is found to drop off substantially at high substrate temperatures, with little or no carbon deposited beyond a temperature of 1070 °C. The growth behavior in response to changes in flame equivalence ratio and substrate temperature is discussed in terms of the possible role that oxygen-containing species may have on surface chemistry. The results described here are also used to project a base cost for manufacturing diamond under these process conditions.

scholarly journals Two- and Three-Dimensional Ultrananocrystalline Diamond (UNCD) Structures for a High Resolution Diamond-Based MEMS Technology

1999 ◽  
Vol 605 ◽  
Author(s):  
O. Auciello ◽  
A.R. Krauss ◽  
D.M. Gruen ◽  
E.M. Meyer ◽  
H.G. Busmann ◽  
...  
Keyword(s):  
High Resolution ◽  
Microelectromechanical Systems ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Coarse Grained ◽  
Lithographic Patterning ◽  
Ultrananocrystalline Diamond ◽  
Single Crystal Diamond ◽  
Corrosive Environments ◽  
Long Endurance

AbstractSilicon is currently the most commonly used material for the fabrication of microelectromechanical systems (MEMS). However, silicon-based MEMS will not be suitable for long-endurance devices involving components rotating at high speed, where friction and wear need to be minimized, components such as 2-D cantilevers that may be subjected to very large flexural displacements, where stiction is a problem, or components that will be exposed to corrosive environments. The mechanical, thermal, chemical, and tribological properties of diamond make it an ideal material for the fabrication of long-endurance MEMS components. Cost-effective fabrication of these components could in principle be achieved by coating Si with diamond films and using conventional lithographic patterning methods in conjunction with e. g. sacrificial Ti or SiO2 layers. However, diamond coatings grown by conventional chemical vapor deposition (CVD) methods exhibit a coarse-grained structure that prevents high-resolution patterning, or a fine-grained microstructure with a significant amount of intergranular non-diamond carbon. We demonstrate here the fabrication of 2-D and 3-D phase-pure ultrananocrystalline diamond (UNCD) MEMS components by coating Si with UNCD films, coupled with lithographic patterning methods involving sacrificial release layers. UNCD films are grown by microwave plasma CVD using C60-Ar or CH4-Ar gas mixtures, which result in films that have 3-5 nm grain size, are 10-20 times smoother than conventionally grown diamond films, are extremely resistant to corrosive environments, and are predicted to have a brittle fracture strength similar to that of single crystal diamond.

Selective Growth of Polycrystalline Diamond Thin Films

1992 ◽  
Vol 282 ◽  
Author(s):  
R. Ramesham
Keyword(s):  
Plasma Etching ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Polycrystalline Diamond ◽  
Selective Growth ◽  
Diamond Growth ◽  
Nucleation Density ◽  
Substrate Type ◽  
Temperature Growth ◽  
Single Crystal Diamond

ABSTRACTMicrowave plasma assisted CVD is employed to grow diamond films using a gas mixture of H2 and CH4on various substrates. Diamond has a tendency not to nucleate growth on mirror-smooth finished substrates irrespective of the substrate type (except single crystal diamond). We have developed various processes to enhance the nucleation density of the diamond substantially by damaging or seeding the surface of the substrates. Several process techniques such as 1. silicon nitride and silicon dioxide process, 2. ultrasonic agitation process, 3. selective seeding of diamond by electroplating of Cu, 4. patterning of diamond films by air-microwave plasma etching, etc., were developed to achieve the patterns of diamond on various substrates. Selective growth of doped diamond and low temperature growth of diamond for microelectronic applications have also been achieved by using the above processes (1 and 2). Details on selective diamond growth processes and the morphology of as-deposited selective diamond by SEM are presented.

Diamond growth using carbon monoxide as a carbon source

1992 ◽  
Vol 7 (5) ◽  
pp. 1195-1203 ◽  
Author(s):  
F.M. Cerio ◽  
W.A. Weimer ◽  
C.E. Johnson
Keyword(s):  
Carbon Source ◽  
Gas Phase ◽  
Growth Rates ◽  
Microwave Plasma ◽  
Polycrystalline Diamond ◽  
Chemical Mechanism ◽  
Diamond Surface ◽  
Diamond Growth ◽  
Lower Growth ◽  
Temperature Combustion

Polycrystalline diamond films were produced in a microwave plasma assisted CVD reactor using CO as the carbon source gas. Reactor exhaust gas compositions were determined by mass spectrometry using 2–10% CO and 0–1.5% O2 in H2 feed gas mixtures. The chemistry involved in the gas phase is similar to that which occurs when diamond is grown using hydrocarbons as carbon source gases. A chemical mechanism for the oxidation of CH4 in flames appears to be applicable to this system. Addition of O2 to the reactor feed gas results in increased growth rates for low addition levels possibly due to activation of the diamond surface, while lower growth rates result at high addition levels due to oxidation of carbon from the surface and depletion of diamond growth precursors in the gas phase. The chemical reactions that take place in the plasma are similar to those that occur in flames and hot filament reactors, indicating that the plasma acts to induce reactions that are normally associated with high temperature combustion processes.

Growth-rate dependence of the thermal conductivity of chemical-vapor-deposited diamond

1999 ◽  
Vol 14 (9) ◽  
pp. 3720-3724 ◽  
Author(s):  
Naira M. Balzaretti ◽  
Albert Feldman ◽  
Edgar S. Etz ◽  
Roy Gat
Keyword(s):  
Thermal Conductivity ◽  
Growth Rate ◽  
Thermal Diffusivity ◽  
Microwave Plasma ◽  
Plasma Reactor ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Diamond Growth ◽  
Diffusivity Measurements ◽  
Chemical Vapor Deposited

The in-plane thermal diffusivity of chemical-vapor-deposited diamond films was measured as a function of diamond-growth rate. The films, 0.1–0.4 mm thick, were prepared in microwave-plasma reactor at growth rates ranging from 1 to 10 μm/h. A modification of Ångstöm's method was used to perform the diffusivity measurements. The thermal conductivity calculated from the thermal diffusivity shows an inverse relationship with growth rate. Analyses of Raman spectra indicate that both the line shifts and the line widths of the diamond Raman peak are practically independent of the deposition rate, except for the specimen grown at the highest growth rate.

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