Epitaxial Growth of Aluminum Nitride on Sapphire and Silicon

1994 ◽  
Vol 358 ◽  
Author(s):  
K. Dovidenko ◽  
S. Oktyabrsky ◽  
J. Narayan ◽  
M. Razeghi
Keyword(s):  
Epitaxial Growth ◽  
Substrate Surface ◽  
Wide Band ◽  
X Ray Diffraction ◽  
Wide Band Gap ◽  
High Quality ◽  
Microstructural Characteristics ◽  
X Ray ◽  
Si Substrates ◽  
Transmission Electron

ABSTRACTThe microstructural characteristics of wide band gap semiconductor, hexagonal A1N thin films on Si(100), (111), and sapphire (0001) and (10ī2) were studied by transmission electron microscopy (TEM) and x-ray diffraction. The films were grown by MOCVD from TMA1 + NH3 + N2 gas mixtures. Different degrees of film crystallinity were observed for films grown on α-A12O3 and Si substrates in different orientations. The epitaxial growth of high quality single crystalline A1N film on (0001) α-Al2O3 was demonstrated with a dislocation density of about 2*10 10cm−2 . The films on Si(111) and Si(100) substrates were textured with the c-axis of A1N being perpendicular to the substrate surface.

Stress origin and relaxation in epitaxial AlN thin films on SiC

2001 ◽  
Vol 696 ◽  
Author(s):  
Ravi Bathe ◽  
R.D. Vispute ◽  
Daniel Habersat ◽  
R. P. Sharma ◽  
T. Venkatesan ◽  
...  
Keyword(s):  
Thin Films ◽  
Rutherford Backscattering Spectrometry ◽  
Wide Band ◽  
X Ray Diffraction ◽  
Wide Band Gap ◽  
X Ray ◽  
Force Microscopy ◽  
Ion Channeling ◽  
Atomic Force ◽  
Highly Strained

AbstractWe have investigated the epitaxy, surfaces, interfaces, and defects in AlN thin films grown on SiC by pulsed laser deposition. The stress origin, evolution, and relaxation in these films is reported. The crystalline structure and surface morphology of the epitaxially grown AlN thin films on SiC (0001) substrates have been studied using x-ray diffraction (θ–2θ, ω, and Ψ scans) and atomic force microscopy, respectively. The defect analysis has been carried out by using Rutherford backscattering spectrometry and ion channeling technique. The films were grown at various substrate temperatures ranging from room temperature to 1100 °C. X-ray diffraction measurements show highly oriented AlN films when grown at temperatures of 750- 800 °C, and single crystals above 800 °C. The films grown in the temperature range of 950 °C to 1000 °C have been found to be highly strained, whereas the films grown above 1000 °C were found to be cracked along the crystallographic axes. The results of stress as a function of growth temperature, thermal mismatch, growth mode, and buffer layer thickness will be presented, and the implications of these results for wide band gap power electronics will be discussed.

Design and Functionalization of Magnetic Core-Shell Oxide Nanoparticles Exhibiting Exchange Bias Features

2011 ◽  
Vol 1359 ◽  
Author(s):  
Fayna Mammeri ◽  
Faïza Mamèche ◽  
Zeinab Kataya ◽  
Nader Yaacoub ◽  
Anna Slawska-Waniewska ◽  
...  
Keyword(s):  
Exchange Bias ◽  
Shell Thickness ◽  
Magnetic Core ◽  
Oxide Nanoparticles ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Microstructural Characteristics ◽  
X Ray ◽  
Transmission Electron ◽  
Structural And Magnetic Properties

ABSTRACTCore-shell magnetic nanoparticles (CSNPs) composed of a ferrimagnetic core (CoFe2O4) embedded in an antiferromagnetic shell (CoO) were produced using seed mediated growth in a polyol. Different core sizes and shell thicknesses were considered. The structural and magnetic properties of assemblies of these nanoparticles were characterized by means of X-ray Diffraction, Transmission Electron Microscopy, dc-magnetometry (SQUID) and 57Fe Mössbauer spectrometry. The measured EB magnetic field values, at low temperature, are found to be weak whatever the microstructural characteristics of the studied CSMNPs. Simultaneously, both the magnetization and the interparticle interaction (mainly dipolar) appear clearly reduced when the shell thickness increases.

Nanostructure Assembly of Indium Sulphide Quantum Dots and Their Characterization

2008 ◽  
Vol 8 (2) ◽  
pp. 689-694 ◽  
Author(s):  
B. Vigneashwari ◽  
V. Ravichandran ◽  
P. Parameswaran ◽  
S. Dash ◽  
A. K. Tyagi
Keyword(s):  
Quantum Dots ◽  
Colloidal Suspension ◽  
Wide Band ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Wide Band Gap ◽  
X Ray ◽  
Glass Substrates ◽  
Series Of Experiments ◽  
Indium Sulphide

Nanocrystals (∼5 nm) of the semiconducting wide band gap material β-In2S3 obtained by chemical synthesis through a hydrothermal route were characterized for phase and compositional purity. These nanoparticles exhibited quantum confinement characteristics as revealed by a blue-shifted optical absorption. These quantum dots of β-In2S3 were electrically driven from a monodisperse colloidal suspension on to conducting glass substrates by Electophoretic Deposition (EPD) technique and nanostructural thin films were obtained. The crystalline and morphological structures of these deposits were investigated by X-ray diffraction and nanoscopic techniques. We report here that certain interesting nanostructural morphologies were observed in the two-dimensional quantum dot assemblies of β-In2S3. The effect of the controlling parameters on the cluster growth and deposit integrity was also systematically studied through a series of experiments and the results are reported here.

scholarly journals Retention Characteristics of CBTi144 Thin Films Explained by Means of X-Ray Photoemission Spectroscopy

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
G. Biasotto ◽  
A. Z. Simões ◽  
C. S. Riccardi ◽  
M. A. Zaghete ◽  
E. Longo ◽  
...  
Keyword(s):  
Thin Films ◽  
Polar Axis ◽  
Photoemission Spectroscopy ◽  
X Ray Diffraction ◽  
Axis Orientation ◽  
X Ray ◽  
Si Substrates ◽  
Transmission Electron ◽  
Coating Method ◽  
Retention Characteristics

CaBi4Ti4O15(CBTi144) thin films were grown on Pt/Ti/SiO2/Si substrates using a soft chemical solution and spin-coating method. Structure and morphology of the films were characterized by the X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Raman analysis, X-ray photoemission spectroscopy (XPS), and transmission electron microscopy (TEM). The films present a single phase of layered-structured perovskite with polar axis orient. Thea/b-axis orientation of the ferroelectric film is considered to be associated with the preferred orientation of the Pt bottom electrode. XPS measurements were employed to understand the nature of defects on the retention behavior of CBTi144 films. We have observed that the main source of retention-free characteristic of the capacitors is the oxygen environment in the CBTi144 lattice.

scholarly journals Grain Structure and Growth of Dispersed Phase BN-AlN Coatings Grown via Chemical Vapor Deposition

1990 ◽  
Vol 202 ◽  
Author(s):  
Garth B. Freeman ◽  
Woo Y. Lee ◽  
W. J. Lackey ◽  
John A. Hanigofsky ◽  
Karren More
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
Ceramic Coatings ◽  
Grain Structure ◽  
Dispersed Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

ABSTRACTThis paper discusses the variation in microstructures encountered during the separate depositions of boron nitride (BN) and aluminum nitride (A1N) as well as during the codeposition of BNߝA1N dispersed phase ceramic coatings. This combination was chosen in order to take advantage of the self lubricating properties of hexagonal BN along with the hard, erosion resistance of A1N. Films were characterized using scanning and transmission electron microscopy (SEM and TEM), x-ray photoelectron spectroscopy (XPS), and x-ray diffraction (XRD).A range of coating microstructures are possible depending on the conditions of deposition. The best films produced, in terms of hardness, density, and tenacity, were a fine mixture of turbostratic BN and preferentially oriented A1N whiskers aligned with the whisker axis perpendicular to the substrate surface as seen by both electron microscopy and x-ray diffraction.

Epitaxial Ferroelectric Heterostructures of Isotropic Metallc Oxide (SrRuO3) and Pb(Zr0.52Ti0.48)O3

1993 ◽  
Vol 310 ◽  
Author(s):  
C. B. Eom ◽  
R.B. Van Dover ◽  
Julia M. Phillips ◽  
R.M. Fleming ◽  
R.J. Cava ◽  
...  
Keyword(s):  
X Ray Diffraction ◽  
Metallic Oxide ◽  
High Crystalline Quality ◽  
Cross Sectional ◽  
X Ray ◽  
Si Substrates ◽  
Transmission Electron ◽  
Fatigue Characteristics ◽  
Large Remnant Polarization ◽  
Coherent Interfaces

AbstractWe have fabricated epitaxial ferroelectric heterostructures of isotropic metallic oxide (SrRuO3) and ferroelectric thin films [SrRuO3/Pb(Zr0.52Ti0.48)O3 /SrRuO3] on (100) SrTiO3 and YSZ buffer layered Si substrates by 90° off-axis sputtering. These heterostructures have high crystalline quality and coherent interfaces as revealed by X-ray diffraction, Rutherford backscattering spectroscopy and cross-sectional transmission electron microscopy. The ferroelectric layers exhibit superior fatigue characteristics over 1010 cycles with large remnant polarization.

Synthesis and Characterization of Al4SiC4: A “New” Wide Band Gap Semiconductor Material

2015 ◽  
Vol 821-823 ◽  
pp. 974-977 ◽  
Author(s):  
Dimitrios Zevgitis ◽  
Odette Chaix-Pluchery ◽  
Beatrice Doisneau ◽  
Mircea Modreanu ◽  
Joseph La Manna ◽  
...  
Keyword(s):  
Nir Spectroscopy ◽  
Wide Band ◽  
Graphite Crucible ◽  
Structural Quality ◽  
X Ray Diffraction ◽  
Wide Band Gap ◽  
Transmission Electron ◽  
Temperature Solution ◽  
Microscopy Techniques

High temperature solution growth of Al4SiC4 single crystals was carried out from the melt of silicon and aluminium pieces in a graphite crucible used as carbon source (typically 1800°C under 1 bar of argon). The obtained crystals, in the mm scale, were then characterized by a variety of techniques including: Raman spectroscopy, transmission electron microscopy techniques, X-ray diffraction and UV-Vis-NIR spectroscopy. A good structural quality was revealed by TEM, ensuring a well resolved Raman spectrum. The UV-Vis transmission spectrum shows an optical gap located around 2-2.5 eV.

Substrate Surface Dependence of the Microstructure of μc-Si,Ge:H Deposited by Reactive Magnetron Sputtering (RMS)

1995 ◽  
Vol 405 ◽  
Author(s):  
S. M. Cho ◽  
K. Christensen ◽  
D. Wolfe ◽  
H. Ying ◽  
D. R. Lee ◽  
...  
Keyword(s):  
Thin Film ◽  
Magnetron Sputtering ◽  
Substrate Surface ◽  
Reactive Magnetron Sputtering ◽  
Reactive Magnetron ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Film Microstructure ◽  
Substrate Surfaces

AbstractWe have investigated on the effect of different substrate surfaces in changing the microstructure of μc-SixGe1-x:H films prepared by reactive magnetron sputtering. Films were deposited on hydrogen terminated Si(111), Si(100) surfaces, and surfaces chemical and plasma oxides. The thin film microstructure was characterized by Fourier transform infrared spectroscopy (FTIR), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and Raman scattering.

X-Ray Diffraction Analysis of Heteroepitaxial Cd1-yZnyTe on GaAs

1988 ◽  
Vol 144 ◽  
Author(s):  
S. M. Johnson ◽  
W. L. Ahlgren ◽  
M. T. Smith ◽  
B. C. Johnston ◽  
S. Sen
Keyword(s):  
Plastic Deformation ◽  
High Resolution ◽  
Epitaxial Growth ◽  
Vapor Phase ◽  
Gaas Substrate ◽  
Lattice Mismatch ◽  
Tilt Boundary ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray

ABSTRACTX-ray diffraction techniques were used to evaluate Cd1-yZnyTe grown on GaAs substrate orientations of {100}2°, {111}, {012}, and {123}. High-quality layers having compositions at or close to the CdTe and ZnTe binary end points can be grown on GaAs, but most of the ternary compositions have extremely broad rocking curves. Layers grown on {123} and {012} were found to have large tilts toward {111} about <121> that varied systematically with the lattice mismatch; this is consistent with the mismatch being accommodated by the formation of a low-angle tilt boundary at the interface. {111} layers were found to be twinned, and thus {100}2° and {123} appear to better suited for vapor-phase epitaxial growth (VPE). High-resolution x-ray diffractometer measurements showed that the lattice mismatch is almost entirely taken up by plastic deformation, and only a small tetragonal distortion was measured. CdTe was distorted more than ZnTe, and a greater distortion was measured for layers grown on {100}2° than on {111}, in agreement with estimates made using bulk elastic constants.

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