Nucleation Enhancement and Growth Of Diamond Films Using An Enclosed Combustion Flame

1994 ◽  
Vol 349 ◽  
Author(s):  
P. W. Morrison ◽  
A. Somashekhar ◽  
J. T. Glass ◽  
J. T. Prater
Keyword(s):  
Growth Rate ◽  
Diamond Films ◽  
Deposition Process ◽  
Growth Conditions ◽  
Nucleation Density ◽  
Statistical Experimental Design ◽  
Growth Study ◽  
Construct Maps ◽  
Pretreatment Time ◽  
Diamond Peak

ABSTRACTThis research investigates the growth of diamond thin films using an enclosed oxyacetylene torch. Using statistical experimental design, we have systematically explored the parameter space to construct maps of nucleation density, film quality, and growth rate as functions of growth conditions. The deposition process is divided into nucleation enhancement and growth, and each step is optimized separately. In the study of the nucleation enhancement, we vary R = O2/C2H2, substrate-flame distance (z), and pretreatment time and determine the nucleation density and nucleation uniformity using electron microscopy. For the growth study, the variables are R, z, and substrate temperature, and we employ two different Raman scattering measurements to assess film quality. In one case, we determine a quality ratio β = diamond peak/(diamond peak + nondiamond peak); the second indicator is the luminescence determined from the baseline of the spectrum. In the growth study, the best film quality is comparable to the best films grown in an atmospheric flame in which R is cycled. We also find that the growth rate is a factor of 10 less than in the atmospheric flame.

Optimizing diamond growth for an atmospheric oxyacetylene torch

1997 ◽  
Vol 12 (5) ◽  
pp. 1237-1252 ◽  
Author(s):  
Lua'y A. Zeatoun ◽  
Philip W. Morrison
Keyword(s):  
Growth Rate ◽  
Surface Temperature ◽  
Flow Rate ◽  
Gas Flow ◽  
Substrate Surface ◽  
Diamond Films ◽  
Diamond Growth ◽  
Statistical Experimental Design ◽  
Gas Flow Rate ◽  
Open Flame

Diamond growth conditions for an atmospheric combustion flame have been optimized using statistical experimental design. Films are grown on a molybdenum bolt for 40 min at a distance of 1 mm from the flame cone. The diamond films have been characterized using Raman spectroscopy, x-ray diffraction, and scanning electron microscope. The input process variables are varied over a range of conditions: total gas flow rate Q = 2–4 standard liter/min, substrate surface temperature Ts = 800–1000 °C, and flow ratio of O2/C2H2 = R = 0.93–0.99. The experimental response outputs are growth rate, full width half maximum (FWHM) of the diamond Raman peak, Raman diamond fraction (β) in the film, ratio of luminescence to diamond peak height (LR), and the relative intensity of the {220}, {311}, {400}, and {331} orientations. The film quality indices FWHM, β, and LR improve by increasing the gas ratio (R), by increasing substrate surface temperature (Ts), and lowering the growth rate by decreasing total gas flow rate. Diamond film shows a small amount texturing in {220} and {400} orientation at low R and Ts. At high R and low Ts crystals are oriented with the {111} direction normal to the substrate surface. Jet and boundary layer theory have been applied to understand the growth rate, the thickness profile, and the morphological instability of the diamond films. Surface Damkühler calculation shows that the deposition process is marginally controlled by mass transfer. Growth rate of an open flame is higher than for an enclosed flame, while the Raman quality measurements of the enclosed flame are more uniform than open flame over the range of the comparison.

ENHANCED NUCLEATION AND SMOOTHNESS OF NANOCRYSTALLINE DIAMOND FILMS VIA W-C GRADIENT INTERLAYER

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1676-1682 ◽  
Author(s):  
QIUPING WEI ◽  
ZHIMING YU ◽  
LI MA ◽  
DENGFENG YIN
Keyword(s):  
Diamond Films ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Nanocrystalline Diamond ◽  
Cemented Carbide ◽  
Nucleation Density ◽  
Wear Properties ◽  
Nanocrystalline Diamond Films ◽  
And Performance ◽  
Cvd Diamond Coating

CVD diamond coating was deposited on to 13%wt. Co -containing tungsten cemented carbide surfaces using a hot filament chemical vapor deposition (HFCVD) to improve wear properties and performance of WC -13% wt . Co . Prior to the deposition of the diamond films, a W - C gradient intermediate layer had been sputtered on WC -13% wt . Co . The surface and cross-section morphology, phase transformation, and grain size distribution of the samples were investigated by means of field emission scanning electron microscope (SEM), X-ray diffractometer (XRD), and atomic force microscope (AFM), respectively. The results show that W - C gradient intermediate layers can effectively reduce the diffusion of Co in cemented carbide substrates during diamond deposition process, resulting high nucleation density and ultra smooth nanocrystalline diamond films.

Growth of (110)-oriented diamond films by electron-assisted chemical vapor deposition

1993 ◽  
Vol 8 (2) ◽  
pp. 314-320 ◽  
Author(s):  
Kazuo Kumagai ◽  
Koichi Miyata ◽  
Kozo Nishimura ◽  
Koji Kobashi
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Etching Rate ◽  
Carbon Film ◽  
Diamond Films ◽  
Chemical Species ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Nucleation Density

Diamond films were deposited on Si substrates by Electron-Assisted Chemical Vapor Deposition (EACVD) using various methane concentrations below 8.1%. It was found that the deposited films were strongly (110)-oriented. This seemed to arise from a high nucleation density of diamond caused by the initial deposition of an amorphous carbon film. A comparison of the graphite etching rate between EACVD and Microwave Plasma CVD (MPCVD) under the standard growth conditions showed that EACVD was able to etch graphite about five times faster than MPCVD. Hence, it was concluded that the differences in the growth rate and morphology between EACVD and MPCVD arise from the different graphite etching rates as well as different chemical species in the reaction gas.

Diffusion model for deposition of epitaxial GaAs layers prepared by the MOCVD method

1991 ◽  
Vol 56 (10) ◽  
pp. 2020-2029
Author(s):  
Jindřich Leitner ◽  
Petr Voňka ◽  
Josef Stejskal ◽  
Přemysl Klíma ◽  
Rudolf Hladina
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Kinetic Model ◽  
Gas Phase ◽  
Substrate Surface ◽  
Deposition Process ◽  
Hydrogen Atmosphere ◽  
Epitaxial Gaas ◽  
Kinetics Of ◽  
Good Agreement

The authors proposed and treated quantitatively a kinetic model for deposition of epitaxial GaAs layers prepared by reaction of trimethylgallium with arsine in hydrogen atmosphere. The transport of gallium to the surface of the substrate is considered as the controlling process. The influence of the rate of chemical reactions in the gas phase and on the substrate surface on the kinetics of the deposition process is neglected. The calculated dependence of the growth rate of the layers on the conditions of the deposition is in a good agreement with experimental data in the temperature range from 600 to 800°C.

Preparation and characterization of epitaxial iron oxide films

1998 ◽  
Vol 13 (7) ◽  
pp. 2003-2014 ◽  
Author(s):  
Y. Gao ◽  
Y. J. Kim ◽  
S. A. Chambers
Keyword(s):  
Growth Rate ◽  
Iron Oxide ◽  
Oxygen Plasma ◽  
Film Surface ◽  
Surface Region ◽  
Growth Conditions ◽  
Epitaxial Films ◽  
Pure Phase ◽  
Iron Oxide Films

Well-ordered, pure-phase epitaxial films of FeO, Fe3O4, and γ–Fe2O3 were prepared on MgO(001) by oxygen-plasma-assisted MBE. The stoichiometries of these thin films were controlled by varying the growth rate and oxygen partial pressure. Selective growth of γ–Fe2O3 and α–Fe2O3 was achieved by controlling the growth conditions in conjunction with the choice of appropriate substrates. Growth of the iron oxide epitaxial films on MgO at ≥350 °C is accompanied by significant Mg outdiffusion. The FeO(001) film surface exhibits a (2 × 2) reconstruction, which is accompanied by a significant amount of Fe3+ in the surface region. Fe3O4 (001) has been found to reconstruct to a structure. γ–Fe23 (001) film surface is unreconstructed.

Emission characteristics of GaInN/GaN multiple quantum shell nanowire-based LEDs with different p-GaN growth conditions

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sae Katsuro ◽  
Weifang Lu ◽  
Kazuma Ito ◽  
Nanami Nakayama ◽  
Naoki Sone ◽  
...  
Keyword(s):  
Growth Rate ◽  
Shell Growth ◽  
Light Output ◽  
High Growth ◽  
Growth Conditions ◽  
High Growth Rate ◽  
Current Injection ◽  
Emission Characteristics ◽  
Multiple Quantum ◽  
Plane Region

Abstract Improving current injection into r- and m-planes of nanowires (NWs) is essential to realizing efficient GaInN/GaN multiple quantum shell (MQS) NW-based light-emitting diodes (LEDs). Here, we present the effects of different p-GaN shell growth conditions on the emission characteristics of MQS NW-LEDs. Firstly, a comparison between cathodoluminescence (CL) and electroluminescence (EL) spectra indicates that the emission in NW-LEDs originates from the top region of the NWs. By growing thick p-GaN shells, the variable emission peak at around 600 nm and degradation of the light output of the NW-LEDs are elaborated, which is attributable to the localization of current in the c-plane region with various In-rich clusters and deep-level defects. Utilizing a high growth rate of p-GaN shell, an increased r-plane and a reduced c-plane region promote the deposition of indium tin oxide layer over the entire NW. Therefore, the current is effectively injected into both the r- and m-planes of the NW structures. Consequently, the light output and EL peak intensity of the NW-LEDs are enhanced by factors of 4.3 and 13.8, respectively, under an injection current of 100 mA. Furthermore, scanning transmission electron microscope images demonstrate the suppression of dislocations, triangular defects, and stacking faults at the apex of the p-GaN shell with a high growth rate. Therefore, localization of current injection in nonradiative recombination centers near the c-plane was also inhibited. Our results emphasize the possibility of realizing high efficacy in NW-LEDs via optimal p-GaN shell growth conditions, which is quite promising for application in the long-wavelength region.

High growth-rate atomic layer deposition process of cerium oxide thin film for solid oxide fuel cell

2019 ◽  
Vol 45 (3) ◽  
pp. 3811-3815 ◽  
Author(s):  
Jin-Geun Yu ◽  
Byung Chan Yang ◽  
Jeong Woo Shin ◽  
Sungje Lee ◽  
Seongkook Oh ◽  
...  
Keyword(s):  
Thin Film ◽  
Growth Rate ◽  
High Growth ◽  
Atomic Layer ◽  
Deposition Process ◽  
High Growth Rate ◽  
Solid Oxide ◽  
Oxide Thin Film ◽  
Oxide Fuel ◽  
Layer Deposition

Crystalline perfection of chemical vapor deposited diamond films

1990 ◽  
Vol 5 (8) ◽  
pp. 1591-1594 ◽  
Author(s):  
A. V. Hetherington ◽  
C. J. H. Wort ◽  
P. Southworth
Keyword(s):  
Grain Boundaries ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Stacking Faults ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Growth Conditions ◽  
Crystalline Perfection ◽  
Planar Defects ◽  
Chemical Vapor Deposited

The crystalline perfection of microwave plasma assisted chemical vapor deposited (MPACVD) diamond films grown under various conditions has been examined by TEM. Most CVD diamond films thus far reported contain a high density of defects, predominantly twins and stacking faults on {111} planes. We show that under appropriate growth conditions, these planar defects are eliminated from the center of the crystallites, and occur only at grain boundaries where the growing crystallites meet.

scholarly journals The Transformation from (111) to (100): A Routine to Large-Scale Epitaxial Diamond

2020 ◽  
Author(s):  
Yang Wang ◽  
Weihua Wang ◽  
Shilin Yang ◽  
Jiaqi Zhu
Keyword(s):  
Large Scale ◽  
Diamond Films ◽  
Diamond Growth ◽  
Nucleation Density ◽  
Diamond Synthesis ◽  
First Principle ◽  
High Quality ◽  
First Principle Calculations ◽  
Large Size ◽  
Experimental Researches

Diamond is a material with excellent performances which attracts the attention from researchers for decades. Pt (111), owing to its catalytic activity on diamond synthesis, is regarded to be a candidate for diamond hetero-epitaxity, which can enhance nucleation density. Molten surface at diamond growth temperature can also improve mobility and aggregation capability of primitive nuclei. Generally, (100)-oriented is welcomed for the achivement of high quality and large size diamond, since the formation of defects and twins are prevented. First-principle calculations and experimental researches were carried out for the study of transformation of orientation. The transformation from {111} to {100}-oriented diamond has been observed on Pt (111) substrate, which can be promoted by the increase of carbon source concentration and substrate temperature. The process is energetic favorable, which may provides a way towards large-scale (100) diamond films.

Sign in / Sign up

Export Citation Format

Share Document