Crystal Defects in Epitaxial Layer on Nitrogen-doped Czochralski-grown Silicon Substrate (I) –Investigation of the Crystallographic Structure–

2004 ◽  
Vol 43 (4A) ◽  
pp. 1241-1246 ◽  
Author(s):  
Katsuhiko Nakai ◽  
Koichi Kitahara ◽  
Yasumitsu Ohta ◽  
Atsushi Ikari ◽  
Masahiro Tanaka
Keyword(s):  
Epitaxial Layer ◽  
Silicon Substrate ◽  
Crystal Defects ◽  
Crystallographic Structure ◽  
Nitrogen Doped

scholarly journals Elongated Wire-Like Zinc Oxide Nanostructures Synthesized from Metallic Zinc

2012 ◽  
Vol 15 (1) ◽  
pp. 19 ◽  
Author(s):  
El-Shazly M. Duraia ◽  
G.W. Beall ◽  
Zulkhair A. Mansurov ◽  
Tatyana A. Shabanova ◽  
Ahmed E. Hannora
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Silicon Substrate ◽  
Gas Flow ◽  
Flow Direction ◽  
Crystal Defects ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Metallic Zinc ◽  
Zinc Oxide Nanostructures

Elongated wire-like Zinc oxide, nanocombs and nanocrystals have been successfully synthesized on the silicon substrate from the metallic zinc as a starting material. The annealing temperature was as low as 450 ºC in argon atmosphere mixed with about 3% oxygen. Structural analysis using the X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) showed that the existence of two phases; nanowires and crystalline form. Moreover some nanoparticles aggregates were noticed to be attached in the bulk to the sides of the ZnO nanocrystals and sometimes these aggregate attached to the Zinc oxide hexagonal crystal and grow to form nanowire at different angles. Scanning electron microscopy (SEM) investigations for the zinc oxide nanostructure on the silicon substrate showed the formation of the nanocrystals in the gas flow direction and at the low energy sites over the silicon substrate. Photoluminescence (PL) measurements, performed at the room temperature, showed the existence of two basic emissions: narrow ultraviolet (UV) emission at 398 nm which attributed to the near band edge emission of the wide band gap and a very wide, more intensive, green emission at 471 nm corresponds to the crystal defects such as vacancies, interstitial sites in ZnO.

Raman and cathodoluminescence spectroscopies of magnesium-substituted hydroxyapatite powders

2005 ◽  
Vol 20 (4) ◽  
pp. 1009-1016 ◽  
Author(s):  
S. Sprio ◽  
G. Pezzotti ◽  
G. Celotti ◽  
E. Landi ◽  
A. Tampieri
Keyword(s):  
Crystal Defects ◽  
Crystallographic Structure ◽  
Raman Analysis ◽  
Ca Ions ◽  
Synthetic Hydroxyapatite ◽  
Intensity Ratios ◽  
Amorphous Surface ◽  
Analytical Tools ◽  
New Evidence ◽  
Mg Doped

Stoichiometric and magnesium-substituted synthetic hydroxyapatite (HA) powders with different Mg contents were characterized by Raman and cathodoluminescence (CL) spectroscopies. The substitution of Ca ions by Mg is presently of great interest because it may improve activity in the first stage of the bone remodeling process. In this paper, we show new evidence that CL spectroscopy has the capability to detect the presence of crystal defects, related to the presence of magnesium substituting calcium in Mg-doped HA powders. The dependence of CL spectra of stoichiometric and magnesium-doped HA powders on their chemical composition was studied, and the results are compared with Raman analysis and data previously collected by other analytical tools. All the investigated powders showed five distinct CL bands; moreover, in magnesium-doped HA, an additional band at higher energy was found. The intensity ratios between selected CL bands showed some relationships with the powder crystallinity and the estimated amount of magnesium both in the HA lattice and in the amorphous surface layer; moreover the band observed only in magnesium-substituted powders could be directly related to the amount of magnesium entered into the HA lattice. Such results can contribute to improve the knowledge of the crystallographic structure of Mg-substituted hydroxyapatite.

Influences of surface treatment on In0.53Ga0.47As epitaxial layer grown on silicon substrate using trimethylaluminum

2018 ◽  
Vol 646 ◽  
pp. 173-179
Author(s):  
Soo Bin Kim ◽  
Seung Hyun Lee ◽  
Hae Jun Jung ◽  
Myung Su Seo ◽  
Sung Min Kim ◽  
...  
Keyword(s):  
Surface Treatment ◽  
Epitaxial Layer ◽  
Silicon Substrate

Review and Detail Classification of Stacking Faults in 4H-SiC Epitaxial Layer by Mirror Projection Electron Microscopy

2020 ◽  
Vol 1004 ◽  
pp. 314-320
Author(s):  
Kentaro Ohira ◽  
Toshiyuki Isshiki ◽  
Hideki Sako ◽  
Masaki Hasegawa ◽  
Kenji Kobayashi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cross Section ◽  
Epitaxial Layer ◽  
Stacking Faults ◽  
Crystal Defects ◽  
Prismatic Plane ◽  
Classification Result ◽  
Transmission Electron

Stacking faults (SFs) in 4H-SiC epitaxial wafers were inspected by using a mirror projection electron microscope (MPJ) [1, 2]. Dark and bright line contrasts of SFs in MPJ images represent surface morphology and crystal defects located in the epitaxial layer. Inspected SFs were classified into three types of SFs on the basis of the MPJ images. After classification, a cross section of each type of SF was observed by transmission electron microscopy (TEM) to verify the classification result. Complex SFs classified by MPJ images consisted of prismatic plane and basal plane SFs.

scholarly journals 3D printing of crystallographic models and open access databases

2014 ◽  
Vol 70 (a1) ◽  
pp. C1278-C1278 ◽  
Author(s):  
Werner Kaminsky ◽  
Trevor Snyder ◽  
Peter Moeck
Keyword(s):  
Open Access ◽  
3D Printing ◽  
College Education ◽  
Structural Data ◽  
Data Bank ◽  
3D Models ◽  
Crystal Defects ◽  
Crystallographic Structure ◽  
Performance Improvements ◽  
Basic Infrastructure

Although introduced 30 years ago, cost and performance improvements have only recently made 3D printing affordable. The industry wide input file format for 3D printers incorporates explicit mesh - `STL' data. Molecules and crystal structures, when including symmetry, crystal morphologies, or crystal defects are encoded in the parametrical `CIF' syntax. Free software for converting directly CIF data to STL files has just been developed, available online [1]. First examples of printed 3D models from STL-files created with these programs include molecules of sucrose, herapathite [2a], caffeine, humulone [2b], an alpha-quartz crystal and its Japanese {112} twin or a brilliant cut diamond. Far more CIF encoded models are available, even open access. The Crystallography Open Database (COD) features over 245,000 entries and has recently developed into the world's premier open-access source for structures of small to medium unit cell-sized inorganic and molecular crystals [3a], complementing the well-established open-access Worldwide Protein Data Bank [3b]. The Cambridge Crystallographic Data Centre in the United Kingdom provides crystal structure data of small (organic) molecules free for bona fide research [3c]. Structural data on inorganic crystals, metals and alloys can be obtained free of charge from the Inorganic Material Database (AtomWork) [3d]. Related to the COD, the crystallographic open-access databases [3e] ("COD offspring") provide CIF data for interdisciplinary college education. With this basic infrastructure in place, any interested college educator may print out her or his favorite crystallographic structure model in 3D and use it in hands on class room demonstrations [3f].

Investigation of Crystal Defects in Epitaxial Layers on Nitrogen-Doped Substrates and a Method for their Suppression

2003 ◽  
Vol 95-96 ◽  
pp. 11-16
Author(s):  
Katsuhiko Nakai ◽  
Koichi Kitahara ◽  
Yasumitsu Ohta ◽  
Atsushi Ikari ◽  
Masahiro Tanaka
Keyword(s):  
Crystal Defects ◽  
Epitaxial Layers ◽  
Nitrogen Doped

Micro-Raman Scattering Study of Strain Fields in Homo-Epitaxial Layer on Nitrogen-Doped 4H-SiC Substrate

2017 ◽  
Vol 897 ◽  
pp. 283-286
Author(s):  
Daisuke Fukunaga ◽  
Noboru Ohtani ◽  
Masakazu Katsuno ◽  
Shinya Sato ◽  
Hiroshi Tsuge ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Epitaxial Layer ◽  
Tensile Strain ◽  
Nitrogen Concentration ◽  
Phonon Modes ◽  
Cross Sectional ◽  
Strain Fields ◽  
Nitrogen Doped ◽  
Substrate Interface ◽  
Scattering Study

The strain fields in a 4H-SiC homo-epitaxial layer deposited on a nitrogen-doped 4H-SiC substrate were studied using Raman scattering microscopy. The cross-sectional (1-100) and (11-20) surfaces of the epitaxial substrate were examined through the peak shifts of several Raman-active phonon modes for 4H-SiC, and tensile strain was found along the direction of 4° off the c-axis at the epilayer/substrate interface. The effect of the facet trace in the substrate, which has a higher nitrogen concentration than the other parts of the substrate, was also studied. The tensile strain at the epilayer/substrate interface was found to be hardly enhanced for the epilayer deposited on the facet trace.

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