Growth of crack-free GaN on AlN quantum dots on Si(111)substrates by MOCVD

2003 ◽  
Vol 798 ◽  
Author(s):  
W. H. Sun ◽  
J. L. Chen ◽  
L. S. Wang ◽  
S. J. Chua
Keyword(s):  
Quantum Dots ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Optical Microscope ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Transmission Electron ◽  
Pressure Chemical ◽  
Aln Buffer

AlN self-assembled quantum dots (QDs) with high density of ∼ 4.4 × 1010/cm2 on Si(111) substrates have been grown by low-pressure chemical vapor deposition under a very low V/III ratio of 350. We found that using AlN-QD/AlN buffer two-inch GaN epilayers without cracks were grown, indicating the underlying quantum dots play a crucial role in relaxing the stain of GaN epilayer. The quality and morphology were investigated by atom force microscopy, transmission electron microscopy, X-ray diffraction and optical microscope.

Texture Evolution in Si/SiC Layered Structures Deposited on Si(001) by Chemical Vapor Deposition

1998 ◽  
Vol 13 (9) ◽  
pp. 2632-2642 ◽  
Author(s):  
L-O. Björketun ◽  
L. Hultman ◽  
O. Kordina ◽  
J-E. Sundgren
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Texture Evolution ◽  
Chemical Vapor ◽  
Columnar Structure ◽  
Layer Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Pressure Chemical

Texture evolution in Si/SiC multilayers deposited by atmospheric pressure chemical vapor deposition on carbonized Si(001) substrates was investigated using x-ray diffraction and transmission electron microscopy. SiC layers were epitaxial and (001)-oriented. Si layers deposited on the SiC exhibited a columnar structure with predominantly (110) orientation which could be related to the nucleation. Orientational relationships were Si[111] ║ SiC[110] and Si[112] ║ SiC[110]. Also, a low density of (112)-oriented columns was present. Extensive twinning on the vertical {111} planes within the Si columns led to domains of hexagonal stacking up to 10 nm in size with the presence of 2H-Si and 4H-Si. Subsequent SiC layer growth on the (110)-oriented Si layer resulted in a (110)-oriented SiC layer if the Si layer was carbonized prior to growth.

Synthesis of Crystalline C3N4 films and the new C-N Phases

1996 ◽  
Vol 441 ◽  
Author(s):  
Yan Chen ◽  
D. J. Johnson ◽  
R. H. Prince ◽  
Liping Guo ◽  
E. G. Wang
Keyword(s):  
Electron Microscopy ◽  
Vapor Deposition ◽  
Growth Parameters ◽  
Chemical Vapor ◽  
Monoclinic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lattice Constants ◽  
Transmission Electron ◽  
Hot Filament

AbstractCrystalline C-N films composed of α- and β-C3N4, as well as other C-N phases, have been synthesized via bias-assisted hot-filament chemical vapor deposition using a gas mixture of nitrogen and methane. Scanning electron microscopy(SEM), energy dispersive X-ray (EDX) analysis, X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to characterize the films. Lattice constants of the α- and β-C3N4 phases obtained coincide very well with the theoretical values. In addition to these phases, two new C-N phases in the films have been identified by TEM and XRD; one having a tetragonal structure with a = 5.65 Å, c = 2.75Å, and the second having a monoclinic structure with a = 5.065 Å, b= 11.5 Å, c = 2.801 Å and β = 96°. Their stoichiometric values and atomic arrangements have not yet been identified. Furthermore, variation in growth parameters, for example methane concentration, bias voltage, etc., can yield preferred growth of different C-N phases.

Characteristics of Gallium Oxide Nanowires Synthesized by the Metalorganic Chemical Vapor Deposition

2007 ◽  
Vol 539-543 ◽  
pp. 1230-1235 ◽  
Author(s):  
Hyoun Woo Kim ◽  
S.H. Shim
Keyword(s):  
Chemical Vapor Deposition ◽  
Cross Sections ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Metalorganic Chemical

We have synthesized the high-density Ga2O3 nanowires on gold (Au)-coated silicon substrates using metalorganic chemical vapor deposition. The nanowires exhibited one-dimensional structures having circular cross sections with diameters in the range of 30-200 nm. The energy dispersive x-ray spectroscopy revealed that the nanowires contained elements of Ga and O, without Au-related impurities. X-ray diffraction analysis and high-resolution transmission electron microscopy showed that the Ga2O3 nanowires were crystalline.

Detection and Analysis of Phase Separation in Metalorganic Chemical Vapor Deposition InGaN

1997 ◽  
Vol 482 ◽  
Author(s):  
E. L. Piner ◽  
N. A. El-Masry ◽  
S. X. Liu ◽  
S. M. Bedair
Keyword(s):  
Chemical Vapor Deposition ◽  
Phase Separation ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Single Phase ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Metalorganic Chemical

AbstractInGaN films in the 0–50% InN composition range have been analyzed for the occurrence of phase separation. The ñ0.5 jum thick InGaN films were grown by metalorganic chemical vapor deposition (MOCVD) in the 690 to 780°C temperature range and analyzed by θ−20 x-ray diffraction (XRD), transmission electron microscopy (TEM), and selected area diffraction (SAD). As-grown films with up to 21% InN were single phase. However, for films with 28% InN and higher, the samples showed a spinodally decomposed microstructure as confirmed by TEM and extra spots in SAD patterns that corresponded to multiphase InGaN. An explanation of the data based on the GaN-InN pseudo-binary phase diagram is discussed.

SiGe Nanowires Grown by LPCVD: Morphological and Structural Analysis

2010 ◽  
Vol 1258 ◽  
Author(s):  
Andrés Rodríguez ◽  
Jesús Sangrador ◽  
Tomás Rodríguez ◽  
Carmen Ballesteros ◽  
Carmelo Prieto ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Vapor Liquid Solid ◽  
Chemical Vapor Deposition Reactor ◽  
X Ray ◽  
Transmission Electron ◽  
Pressure Chemical ◽  
Scanning Electron

AbstractSiGe nanowires were grown by the vapor-liquid-solid method using a low pressure chemical vapor deposition reactor and different flows of the GeH4 and Si2H6 gas precursors. The morphology of the nanowires was studied by field emission scanning electron microscopy, and the length, diameter and density of nanowires were determined. Their structure and crystallinity were analyzed by transmission electron microscopy and its related techniques. Energy dispersive X-ray emission of individual nanowires as well a Raman spectroscopy were used to determine their composition and to analyze its homogeneity.

scholarly journals Effect of Nucleation Parameters of Ge Quantum Dots Grown over Silicon Oxide by LPCVD

2007 ◽  
Vol 2 (2) ◽  
pp. 81-84
Author(s):  
S. N. M. Mestanza ◽  
I. Doi ◽  
N. C. Frateschi
Keyword(s):  
Quantum Dots ◽  
Silicon Oxide ◽  
Chemical Vapor ◽  
Force Microscopy ◽  
Nucleation Parameters ◽  
Atomic Force ◽  
Transmission Electron ◽  
Pressure Chemical ◽  
Mean Size ◽  
Germanium Quantum Dots

Germanium quantum dots (Ge-QD) were grown by Low Pressure Chemical Vapor Deposition (LPCVD) on Si nucleus previously grown on 3 nm thick SiO2 ultra thin film. Samples were analyzed by atomic force microscopy (AFM) and high resolution transmission electron microscopy (HRTEM). We report the analysis of the influence of the nucleation parameters on size and spatial distribution of Ge-QD. AFM images show a Ge-QD density of around 3.6x1010 cm-2, with an 11 nm mean size and 2.9 nm height. Finally, HRTEM investigation shows that the Ge-QD have a crystalline structure, i.e., they are nanocrystals.

Deposition and Properties of AlN Films Prepared by Low Pressure CVD with a Metalorganic Precursor

1993 ◽  
Vol 335 ◽  
Author(s):  
M. J. Cook ◽  
P. K. Wu ◽  
N. Patibandla ◽  
W. B. Hillig ◽  
J. B. Hudson
Keyword(s):  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Low Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fiber Coating ◽  
Pressure Chemical ◽  
Substrate Temperatures ◽  
Carbon Concentrations

AbstractAluminum nitride films were deposited on Si (100) and sapphire (1102) substrates by low pressure chemical vapor deposition using the metalorganic precursor trisdimethylaluminum amide, [(CH3)2AlNH2]3. Depositions were carried out in a cold wall reactor with substrate temperatures between 500 and 700 °C and precursor temperatures between 50 and 80 °C. The films were analyzed by X-ray photoelectron spectroscopy, X-ray diffraction, optical microscopy and scanning electron microscopy. The films were generally smooth and adherent with colors ranging from transparent to opaque grey. Cracking and spallation were seen to occur at high film thickness. Deposition rates ranged from 20 to 300 Å/min and increased with both precursor and substrate temperature. Carbon concentrations were small, < 5 at. %, while oxygen concentrations were higher and showed a characteristic profile versus depth in the film. High temperature compatibility testing with sapphire/AlN/MoSi2 samples was carried out to determine film effectiveness as a fiber coating in a composite.

Optical And Structural properties of Vertical Aligned Self-Assembled InAs Quantum Dots Multilayers

2001 ◽  
Vol 676 ◽  
Author(s):  
J. C. González ◽  
M. I. N. da Silva ◽  
W. N. Rodrigues ◽  
F. M. Matinaga ◽  
R. Magalhaes-Paniago ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Structural Properties ◽  
Molecular Beam ◽  
X Ray Diffraction ◽  
Inas Quantum Dots ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Self Assembled

ABSTRACTIn this work, we report optical and structural properties of vertical aligned self-assembled InAs quantum dots multilayers. The InAs quantum dots samples were grown by Molecular Beam Epitaxy. Employing Atomic Force Microscopy, Transmission Electron Microscopy, and Gracing Incident X-ray Diffraction we have studied the structural properties of samples with different number of periods of the multiplayer structure, as well as different InAs coverage. The optical properties were studied using Photoluminescence spectroscopy.

Crystalline Orientation of PbTiO3 Nanorods Grown by MOCVD Using ZnO Nanorods as a Template

2011 ◽  
Vol 1292 ◽  
Author(s):  
Hironori Fujisawa ◽  
Masaru Shimizu ◽  
Ryohei Kuri ◽  
Seiji Nakashima ◽  
Yasutoshi Kotaka ◽  
...  
Keyword(s):  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Zno Nanorods ◽  
Chemical Vapor ◽  
Piezoresponse Force Microscopy ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Crystalline Orientation ◽  
X Ray ◽  
Force Microscopy

ABSTRACTPbTiO3-covered ZnO nanorods were grown on Al2O3$\left({11\bar 20} \right)$ by metalorganic chemical vapor deposition (MOCVD), and their crystalline orientation was investigated by x-ray diffraction (XRD). Structural analysis by scanning electron microscopy and XRD revealed that the hexagonal ZnO nanorods had $\left\{ {10\bar 10} \right\}$-side facets. XRD analysis of PbTiO3 thin films on ZnO$\left({10\bar 10} \right)$/Al2O3$\left({10\bar 10} \right)$revealed that PbTiO3 was epitaxially grown on ZnO$\left({10\bar 10} \right)$, showing 6 variants of crystallites with the c-axis tilted either 27o or 69o from the surface normal to the ZnO$\left({10\bar 10} \right)$ plane. Effective piezoelectric coefficients calculated for the 27o and 69o-crystallites using piezoresponse force microscopy confirm that deformation of nanorods and nanotubes contributed to the large electrically-induced strain along the radial direction.

scholarly journals Metal film deposition by laser breakdown chemical vapor deposition

1986 ◽  
Vol 1 (3) ◽  
pp. 420-424 ◽  
Author(s):  
T.R. Jervis ◽  
L.R. Newkirk
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Vapor Deposition ◽  
Gas Phase ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Film Deposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

Dielectric breakdown of gas mixtures can be used to deposit thin films by chemical vapor deposition with appropriate control of flow and pressure conditions to suppress gas-phase nucleation and particle formation. Using a pulsed CO2 laser operating at 10.6 μ where there is no significant resonant absorption in any of the source gases, homogeneous films from several gas-phase precursors have been sucessfully deposited by gas-phase laser pyrolysis. Nickel and molybdenum from the respective carbonyls representing decomposition chemistry and tungsten from the hexafluoride representing reduction chemistry have been demonstrated. In each case the gas precursor is buffered with argon to reduce the partial pressure of the reactants and to induce breakdown. Films have been characterized by Auger electron spectroscopy, x-ray diffraction, transmission electron microscopy, pull tests, and resistivity measurements. The highest quality films have resulted from the nickel depositions. Detailed x-ray diffraction analysis of these films yields a very small domain size consistent with the low temperature of the substrate and the formation of metastable nickel carbide. Transmission electron microscopy supports this analysis.

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