A Study of Nucleation and Growth in MOCVD: The Growth of Thin Films of Alumina

2000 ◽  
Vol 648 ◽  
Author(s):  
M.P. Singh ◽  
S. Mukhopadhayay ◽  
Anjana Devi ◽  
S.A. Shivashankar
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Secondary Ion Mass Spectrometry ◽  
Film Growth ◽  
Depth Profiling ◽  
Chemical Vapor ◽  
Nucleation And Growth ◽  
Cross Sectional ◽  
Alumina Films ◽  
Pressure Chemical

AbstractWe have studied the nucleation and growth of alumina by metalorganic chemical vapor deposition (MOCVD). The deposition of alumina films was carried out on Si(100) in a horizontal, hot-wall, low pressure chemical vapor deposition (CVD) reactor, using aluminum acetylacetonate{Al(acac)3}as the CVD precursor. We have investigated growth of alumina films as a function of different CVD parameters such as substrate temperature and total reactor pressure during film growth. Films were characterized by optical microscopy, X-ray diffractometry (XRD), scanning electron microscopy (SEM), cross-sectional SEM, and secondary ion mass spectrometry (SIMS) compositional depth profiling. The chemical analysis reveals that the carbon is present throughout the depth of the films.

Modeling of Silicon Nanodots Nucleation and Growth Deposited by LPCVD on SiO2 : From Molecule/surface Interactions to Reactor Scale Simulations

2006 ◽  
Vol 959 ◽  
Author(s):  
Ilyes Zahi ◽  
Hugues Vergnes ◽  
Brigitte Caussat ◽  
Alain Esteve ◽  
Mehdi Djafari Rouhani ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Deposition Time ◽  
Chemical Vapor ◽  
Surface Interactions ◽  
Nucleation And Growth ◽  
High Dilution ◽  
First Results ◽  
Pressure Chemical ◽  
Molecule Surface

ABSTRACTWe present first results combining models at continuum and atomistic (DFT) levels to improve understanding of key mechanisms involved in silicon nanodots (NDs) synthesis on SiO2 by Low Pressure Chemical Vapor Deposition (LPCVD) from silane SiH4. In particular, by simulating an industrial LPCVD reactor using the CFD code Fluent, we find that the deposition time could be increased and then the reproducibility and uniformity of NDs deposition could be improved when highly diluting silane in a carrier gas. A consequence of this high dilution seems to be that the contribution to deposition of unsaturated species such as silylene SiH2 highly increases. This result is important since our first DFT calculations have shown that silicon chemisorption on silanol Si-OH or siloxane Si-O-Si bonds present on SiO2 substrates could only proceed from silylene (and probably from other unsaturated species). The silane saturated molecule could only contribute to NDs growth, i.e. silicon chemisorption on already deposited silicon bonds. Increasing silylene contribution to deposition in highly diluting silane could then also exalt silicon nucleation on SiO2 substrates and then increase NDs density.

scholarly journals Space filling by nucleation and growth in chemical vapor deposition of diamond

1996 ◽  
Vol 11 (3) ◽  
pp. 716-726 ◽  
Author(s):  
J. Stiegler ◽  
Y. von Kaenel ◽  
M. Cans ◽  
E. Blank
Keyword(s):  
Image Analysis ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Surface Coverage ◽  
Film Growth ◽  
Chemical Vapor ◽  
Particle Growth ◽  
Particle Formation ◽  
Nucleation And Growth ◽  
Space Filling

Phase transformations, including chemical vapor deposition (CVD) of diamond, taking place by nucleation and growth are commonly described by Avrami or Johnson-Mehl type models. In order to avoid the restrictions of such models with respect to assumptions concerning nucleation rates and growth velocities, the variation with time of nucleation and growth of diamond particles during the deposition of microwave plasma-assisted CVD was studied. The size distributions obtained from image analysis enabled us to trace back details of the nucleation and growth history. Three sources of particle formation were operating during deposition. A general growth law suitable for all particles did not exist. These observations limited the applicability of Avrami-type models to describe space filling. Computer simulation of surface coverage and particle growth was successful because one particular mode of particle formation and growth dominated surface coverage. Based on image analysis and the determination of the film growth rate, the evolution of the diamond volume fraction with time, starting from three-dimensional particle growth followed by a continuous transition to one-dimensional film growth, was described.

Chemical Vapor Deposition of Titania/Silica and Zirconia Films

2001 ◽  
Vol 670 ◽  
Author(s):  
Wayne L. Gladfelter ◽  
Ryan C. Smith ◽  
David Burleson ◽  
Charles J. Taylor ◽  
Jeffrey T. Roberts ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Film Deposition ◽  
X Rays ◽  
Cross Sectional ◽  
Specific Chemical ◽  
Pressure Chemical ◽  
State Growth

ABSTRACTAmorphous thin films of composition TixSi1−xO2 have been grown by low pressure chemical vapor deposition on silicon (100) substrates using Si(OEt)4 and either Ti(OiPr)4 or anhydrous Ti(NO3)4 as the sources of SiO2 and TiO2, respectively. The substrate temperature was varied between 300 and 535°C, and the precursor flow rates ranged from 5 to 100 sccm. Under these conditions growth rates ranging from 0.6 to 90.0 nm/min were observed. Films were amorphous to X-rays as deposited and SEM micrographs showed smooth, featureless film surfaces. Cross-sectional TEM showed no compositional inhomogeneity. RBS revealed that x (from the formula TixSi1−xO2) was dependent upon the choice of TiO2 precursor. For films grown using TTIP-TEOS x could be varied by systematic variation of the flow of N2 through the precursor vessels or the deposition temperature. For the case of TN-TEOS x remained close to 0.5. The results suggested the existence of a specific chemical reaction between TN and TEOS prior to film deposition.The CVD of zirconium dioxide (ZrO2) films from zirconium tetra-tert-butoxide {Zr[OC(CH3)3]4} is also described. The films, which were deposited on Si(100), were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), ellipsometry, X-ray diffraction (XRD), and Rutherford backscattering spectroscopy (RBS). Deposition was studied between ∼380 and 825 °C, and at precursor pressures between 4 × 10−5 and 1 × 10−4 Torr. The kinetics for steady-state growth were studied as functions of temperature and precursor pressure. Results were fit to a two-step kinetic model involving reversible precursor adsorption followed by irreversible decomposition to ZrO2.

Heteroepitaxial Si1-x-yGex Cy Layer Growth on (100)Si by Atmospheric Pressure Chemical Vapor Deposition

1995 ◽  
Vol 399 ◽  
Author(s):  
Z. Atzmon ◽  
A. E. Bair ◽  
T. L. Alford ◽  
D. Chandrasekhar ◽  
David J. Smith ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Atmospheric Pressure ◽  
Rutherford Backscattering Spectrometry ◽  
Chemical Vapor ◽  
Layer Growth ◽  
Misfit Dislocations ◽  
Cross Sectional ◽  
Good Crystallinity ◽  
Pressure Chemical

ABSTRACTThin heteroepitaxial films of Si1-x-yGexCy have been grown on (100)Si substrates using atmospheric pressure chemical vapor deposition at 550 and 700°C. The crystallinity, composition and microstructure of the SiGeC films were characterized using Rutherford backscattering spectrometry (ion channeling), secondary-ion-mass-spectrometry and cross-sectional transmission electron microscopy. SiGeC films with up to 2% C were grown at 700°C with good crystallinity and very few interracial defects, while misfit dislocations at the SiGe/Si interface were observed for SiGe films grown under the same conditions. This difference indicates that the presence of carbon in the SiGe matrix increases the critical thickness of the grown layers. SiGeC thin films (>110 nm) with up to 3.5% C were grown at 550°C with good crystallinity. The crystallinity of the films grown at lower temperature (550°C) was less sensitive to the flow rate of the C source (C2H4), which enabled growth of single crystal SiGeC films with higher C content.

Characteristics of SiC Heteroepitaxial Growth on Si by Hot-Mesh Chemical Vapor Deposition

2006 ◽  
Vol 11-12 ◽  
pp. 265-268
Author(s):  
T. Kurimoto ◽  
Yuichiro Kuroki ◽  
Kanji Yasui ◽  
Masasuke Takata ◽  
Tadashi Akahane
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Film Growth ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
Heteroepitaxial Growth ◽  
Cross Sectional ◽  
Optical Absorbance ◽  
Si Substrates ◽  
Hydrogen Radicals

The heteroepitaxial growth of 3C-SiC films on Si(100) substrates by the hot-mesh chemical vapor deposition (HM-CVD) method using monomethylsilane as a source gas was investigated. From the results of X-ray diffraction spectra, 3C-SiC crystal was epitaxially grown on Si substrates at substrate temperatures above 750°C. The SiC/Si interface was observed by cross-sectional scanning electron microscopy, and was confirmed to be void-free and smooth. The density of hydrogen radicals supplied to the substrate surface during the growth was also estimated measuring the optical absorbance change of tungsten phosphate glass plates. From the dependence of the growth rate on substrate temperature, the mechanism of SiC film growth by HM-CVD was considered.

Epitaxial film growth of chromium dioxide by low pressure chemical vapor deposition using chromium carbonyl

2010 ◽  
Vol 518 (23) ◽  
pp. 6853-6857 ◽  
Author(s):  
Jinwen Wang ◽  
Manjit Pathak ◽  
Xing Zhong ◽  
Patrick LeClair ◽  
Tonya M. Klein ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Epitaxial Film ◽  
Film Growth ◽  
Chemical Vapor ◽  
Low Pressure ◽  
Chromium Dioxide ◽  
Chromium Carbonyl ◽  
Pressure Chemical ◽  
Epitaxial Film Growth

Chemical Vapor Deposition of Highly Transparent and Conductive Boron Doped Zinc Oxide Thin Films

1992 ◽  
Vol 242 ◽  
Author(s):  
Jianhua Hu ◽  
Roy G. Gordon
Keyword(s):  
Zinc Oxide ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Film Growth ◽  
Chemical Vapor ◽  
Optical Measurements ◽  
Visible Absorption ◽  
Boron Doped ◽  
Pressure Chemical ◽  
Crystallite Sizes

ABSTRACTBoron doped zinc oxide films have been successfully deposited from a gas mixture of 0.05% diethyl zinc, 2.3% ethanol and various diborane concentrations in the temperature range 300°C to 430°C in an atmospheric pressure chemical vapor deposition reactor. The dopant diborane was found to decrease the film growth rate. The crystallite sizes of doped films were smaller than those of undoped films. Hall coefficient and resistance measurements at room temperatures gave conductivities between 250 and 1700 Ω-1, electron densities between 1.4×1020 and 6.7×1020 cm-3, and mobilities between 7 and 23 cm2/V-s. Optical measurements showed that a film with a sheet resistance of 8.8 Ω/square has an average visible absorption of about 8% and maximum infrared reflectance close to 85%. The ratio of conductivity to absorption coefficient is between 0.05 Ω-1 and 0.55 Ω-1. The band gap of doped film was widened and followed the Burstein-Moss relation.

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