Defect Pair Formation by Implantation-Induced Stresses in High-Dose Oxygen Implanted Silicon-on-Insulator Material

1993 ◽  
Vol 316 ◽  
Author(s):  
J.D. Lee ◽  
J.C. Park ◽  
D. Venables ◽  
S.J. Krause ◽  
P. Roitman
Keyword(s):  
Defect Density ◽  
Silicon On Insulator ◽  
Surface Strain ◽  
High Dose ◽  
X Ray Diffraction ◽  
Near Surface ◽  
X Ray ◽  
Density Reduction ◽  
Transmission Electron ◽  
Pair Density

ABSTRACTDefect microstructure and the near-surface strain of high-dose oxygen implanted silicon-on-insulator material (SIMOX) were investigated as a function of dose, implant temperature, and annealing temperature by transmission electron microscopy and high resolution x-ray diffraction. Dislocation half loops (DHLs) begin to form by stress assisted climb at a critical stress level due to implantation-induced damage. DHLs evolve into through-thickness defect (TTD) pairs by expansion during annealing. Both DHL and TTD-pair density increase with higher implant dose and lower implant temperature. Possible methods for defect density reduction are suggested based on the results of this study.

Low-cost thermo-chemical process of TiO2 powder purification: Study of iterative gettering effect

2021 ◽  
Author(s):  
Nesrine Jaouabi ◽  
Wala Medfai ◽  
Marouan Khalifa ◽  
Rabia Zaghouani ◽  
Hatem Ezzaouia
Keyword(s):  
Porous Layer ◽  
Sacrificial Layer ◽  
Low Cost ◽  
Nir Spectroscopy ◽  
Tio2 Powder ◽  
X Ray Diffraction ◽  
X Ray ◽  
Density Reduction ◽  
Transmission Electron ◽  
Layer Effect

The titanium dioxide (TiO2) purity is very important for the TiO2-based applications making essential the impurities density reduction. In this study, we propose an efficient purification process of TiO2 powder in order to reduce impurities. The low-cost proposed approach is based on an iterative gettering (IG) process combining three main steps: (1) a porous TiO2 sacrificial layer formation (p-TiO2), (2) a rapid thermal annealing (RTA) of p-TiO2 powder in an infrared oven at 950°C under air permitting the residual impurities diffusion to the porous layer surface and (3) etching in acid solution to remove the porous layer. Effect of the proposed gettering process on purification efficiency was evaluated by different characterization techniques such as the transmission electron microscopy (TEM), the energy dispersive x-ray spectroscopy (EDX), the UV–Visible-NIR spectroscopy, the X-ray diffraction (XRD) and atomic absorption spectroscopy (AAS). The obtained results showed the efficient removal of metal impurities, such as Cu, Al, P, and Fe confirming the efficiency of the process improving the purity from 89% to 99.96%.

scholarly journals X-ray characterization of Ge dots epitaxially grown on nanostructured Si islands on silicon-on-insulator substrates

2013 ◽  
Vol 46 (4) ◽  
pp. 868-873 ◽  
Author(s):  
Peter Zaumseil ◽  
Grzegorz Kozlowski ◽  
Yuji Yamamoto ◽  
Markus Andreas Schubert ◽  
Thomas Schroeder
Keyword(s):  
Tensile Strain ◽  
Chemical Vapour ◽  
Grazing Incidence ◽  
Silicon On Insulator ◽  
Misfit Dislocations ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Soi Substrates ◽  
Nanostructured Si

On the way to integrate lattice mismatched semiconductors on Si(001), the Ge/Si heterosystem was used as a case study for the concept of compliant substrate effects that offer the vision to be able to integrate defect-free alternative semiconductor structures on Si. Ge nanoclusters were selectively grown by chemical vapour deposition on Si nano-islands on silicon-on-insulator (SOI) substrates. The strain states of Ge clusters and Si islands were measured by grazing-incidence diffraction using a laboratory-based X-ray diffraction technique. A tensile strain of up to 0.5% was detected in the Si islands after direct Ge deposition. Using a thin (∼10 nm) SiGe buffer layer between Si and Ge the tensile strain increases to 1.8%. Transmission electron microscopy studies confirm the absence of a regular grid of misfit dislocations in such structures. This clear experimental evidence for the compliance of Si nano-islands on SOI substrates opens a new integration concept that is not only limited to Ge but also extendable to semiconductors like III–V and II–VI materials.

scholarly journals From imperfect to perfect Bi2Sr2CaCu2Ox (Bi–2212) grains

1993 ◽  
Vol 8 (9) ◽  
pp. 2170-2176 ◽  
Author(s):  
B. Heeb ◽  
L.J. Gauckler ◽  
H. Heinrich ◽  
G. Kostorz
Keyword(s):  
Electron Microscopy ◽  
Defect Density ◽  
Formation Rate ◽  
Great Majority ◽  
Zone Melting ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
State Process ◽  
Transmission Electron

The 2212 phase formation during annealing of melt textured Bi–2212 (Bi2Sr2CaCu2Ox) was investigated using differential thermal analysis, thermal gravimetric analysis, x-ray diffraction, scanning electron microscopy, energy dispersive x-ray analysis, and high resolution transmission electron microscopy. After zone melting, the material is multiphase consisting of 2212, 2201, Sr1−xCaxCuO2, and the eutectic. The 2212 phase formed is highly perfect with less than 5% intergrowths of 2201 layers; the 2201 phase shows no intergrowth of 2212 at all. In the first period of the annealing, remelting of the eutectic leads to fast oxygen diffusion and a high 2212 formation rate. The 2201 → 2212 transformation proceeds via intermediate states of high defect density. The 2212 grains contain up to 30–70% 2201 intergrowths. Further heat treatments lead to an annihilation of the great majority of intergrown 2201 layers. We propose a model for the formation of 2212 grains with a low planar defect density, based on frequent stacking faults, that allows diffusion of Ca- and Cu-atoms over a short distance. The model provides a schematic description of this solid-state process and correlates it to the characteristic microstructural features of melt-processed Bi–2212.

Synthesis and Characterization of A Metastable (SiC)aN4 Phase

1994 ◽  
Vol 354 ◽  
Author(s):  
C. Uslu ◽  
B. Park ◽  
D. B. Poker
Keyword(s):  
Cubic Phase ◽  
High Dose ◽  
Sensitive Detector ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron ◽  
Position Sensitive ◽  
New Phase

AbstractA metastable C-Si-N compound has been synthesized by high dose N+ implantation into polycrystalline /8-SiC (cubic phase). The thin films formed upon 100 keV implantations were characterized with respect to various ion doses and target temperatures. X-ray diffraction with a position-sensitive detector and cross-sectional transmission electron microscopy revealed that the as-implanted surfaces contained ∼0.15 jttm thick continuously-buried amorphous layers. Rutherford backscattering spectroscopy showed that the peak concentration of nitrogen saturated up to approximately 54 at. % with increasing doses, suggesting a new phase formation.

scholarly journals Formation of Niobium Carbides in High-Dose Carbon-Ion-Implanted and Annealed Niobium

1989 ◽  
Vol 157 ◽  
Author(s):  
J. S. Huang
Keyword(s):  
Narrow Range ◽  
Nucleation And Growth ◽  
High Dose ◽  
Carbon Ions ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Glancing Angle ◽  
Total Fluence

ABSTRACTPolycrystalline niobium was implanted with 200-keV C+ ions to a total fluence of 7 × 1017 carbon ions per cm2 (C/cm2). Auger electron spectroscopy (AES) analysis showed that the carbon concentration varied from 5 to 50 at.% within a depth of about 4000 Å. Glancing-angle x-ray diffraction analysis (XRDA) and transmission electron microscopy (TEM) analysis indicated that no Nb2C phase was formed and that a buried fee NbC layer was formed in the region where carbon content exceeds about 40 at.%. The absence of Nb2C was attributed to its narrow range of solubility for carbon and the low diffusivity of carbon atoms. The possibility of the NbC precipitation by nucleation and growth or by a diffusionless martensitic transformation is discussed. When the implanted samples were annealed at 1273 K for 1 h, an orthorhombic Nb2C phase formed as spherical precipitates and the implanted carbon redistributed.

High quality GdSil.7 layers formed by high dose channeled implantation

1996 ◽  
Vol 427 ◽  
Author(s):  
M. F. Wu ◽  
A. Vantomme ◽  
H. Pattyn ◽  
G. Langouche ◽  
H. Bender
Keyword(s):  
Ion Beam ◽  
Hexagonal Phase ◽  
Hexagonal Structure ◽  
High Dose ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Silicide Layer ◽  
Transmission Electron ◽  
Better Than

AbstractThin gadolinium silicide layers have been formed by channeled ion beam synthesis. Continuous and heteroepitaxial GdSil.7 layers with a hexagonal structure and a χmin value of 10% are prepared by Gd ion implantation at 90 keV to a dose of 1.3x1017/cm2 at 450°C in Si(111) using channeled implantation. The hexagonal phase of GdSi1.7 is stable up to a temperature of 850°C. Both the crystalline quality and the phase stability are much better than the results obtained by conventional techniques. Annealing at > 900°C suddenly changes the χmin value of the silicide layer from 10% to 100%. X-ray diffraction shows that the phase has changed to orthorhombic. RBS/channeling, x-ray diffraction and transmission electron microscopy are used in this study.

scholarly journals Повышение эффективности фильтрации прорастающих дислокаций в темплейтах AlN/c-Al-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=- с фасетированной морфологией поверхности во время их роста методом молекулярно-пучковой эпитаксии

2020 ◽  
Vol 46 (11) ◽  
pp. 26
Author(s):  
А.В. Мясоедов ◽  
Д.В. Нечаев ◽  
В.В. Ратников ◽  
А.Е. Калмыков ◽  
Л.М. Сорокин ◽  
...  
Keyword(s):  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Buffer Layers ◽  
X Ray Diffraction ◽  
Transmission Electron Microscopy Study ◽  
X Ray ◽  
Density Reduction ◽  
Transmission Electron ◽  
Dislocations Density ◽  
Aln Buffer

The results of transmission electron microscopy study and X-ray diffraction analysis of AlN/c Al2O3 templates with GaN ultrathin insertions grown by plasma-assisted molecular beam epitaxy are presented. It is shown that AlN buffer layers with faceted surface morphology provide a much higher threading dislocations density reduction then with smooth layers. The filtering action of ultrathin GaN insertions is confirmed.

Growth temperature dependence of crystal symmetry in Nb-doped BaTiO3 thin films

2013 ◽  
Vol 03 (02) ◽  
pp. 1350009 ◽  
Author(s):  
Young Heon Kim ◽  
Xubing Lu ◽  
Marco Diegel ◽  
Roland Mattheis ◽  
Dietrich Hesse ◽  
...  
Keyword(s):  
Thin Films ◽  
Growth Temperature ◽  
Defect Density ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Threading Defects ◽  
Tetragonal Phase Transition

Growth temperature effects on the microstructure of Nb -doped BaTiO 3 thin films of the composition BaTi 0.98 Nb 0.02 O 3 are studied using X-ray diffraction and transmission electron microscopy (TEM). Reciprocal space maps and electron diffraction patterns show that the a-axis lattice parameter increases and the c-axis parameter decreases with increasing growth temperature, indicating a decrease of tetragonality. Bright-field TEM images show low and high densities of threading defects in films grown at low and high temperatures, respectively. The observations are discussed in terms of a hindering of the cubic-to-tetragonal phase transition by a high defect density and a high unit cell volume.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

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