Characteristics of Oxygen Precipitation in Silicon Wafers Preannealed at 723K

1992 ◽  
Vol 262 ◽  
Author(s):  
I. Fusegawa ◽  
E. Iino ◽  
T. Hirohata ◽  
H. Yamagishi
Keyword(s):  
Crystal Growth ◽  
Thermal Treatment ◽  
Single Crystals ◽  
Single Step ◽  
Nonuniform Distribution ◽  
The Other ◽  
Growth Axis ◽  
Oxygen Precipitation ◽  
New Process ◽  
The One

ABSTRACTWe investigated phenomena of oxygen precipitation in silicon single crystals by two kinds of thermal treatment, supposing a CMOS fabrication process. The one consisted of the first annealing at 1123K for 4 hrs and the second annealing at 1423K for 16 hrs. The other one consisted of the annealing at 1273K for 4 hrs and the second annealing at 1423K for 13 hrs. In the results, a single-step preannealing at 723K for 2 hrs was effective for the oxygen precipitation by the former process and nonuniform distribution profiles along crystal growth axis were well improved, however, insufficiently improved against the latter process. We considered a two-step preannealing process consisting of the first annealing at 723K for 2 hrs and the second annealing at 923K for 2 hrs. This new process was effective for the oxygen precipitation by the latter process. Especially, we could obtain uniform distribution profiles of oxygen precipitation along a crystal growth axis.

Oxygen Precipitation Nonuniformity for Thermal History Around 723K During Cz Crystal Growth

1992 ◽  
Vol 262 ◽  
Author(s):  
I. Fusegawa ◽  
H. Yamagishi
Keyword(s):  
Crystal Growth ◽  
Thermal History ◽  
Silicon Single Crystal ◽  
Nonuniform Distribution ◽  
Precipitation Process ◽  
Thermal Treatments ◽  
Distribution Profile ◽  
Oxygen Precipitation ◽  
Thermal Histories ◽  
The One

ABSTRACTWe investigated phenomena of oxygen precipitation nonuni-formity along crystal growth axis due to different thermal histories during CZ crystal growth. The oxygen precipitation process employed in this paper was two-step thermal treatments consisting of the first annealing in nitrogen ambient at 1073K for 4 hrs and the second annealing in dry oxygen ambient at 1273K for 16 hrs. The amount of the oxygen precipitation at the shoulder of a silicon single crystal was higher than the one at the tail end. We found this nonuniform distribution profile was due to the thermal history around 723K during crystal growth. Such an nonuniformity could be improved remarkably by adding a preannealing in dry oxygen ambient at 723K for 2 hrs before the two-step thermal treatment.

The Effect of D-Defect in Silicon Single Crystal on Oxygen Precipitation

1992 ◽  
Vol 262 ◽  
Author(s):  
I. Fusegawa ◽  
N. Fujimaki ◽  
H. Yamagishi
Keyword(s):  
Crystal Growth ◽  
Single Crystal ◽  
Single Crystals ◽  
Thermal Process ◽  
Flow Patterns ◽  
Optical Microscope ◽  
Silicon Single Crystal ◽  
Thermal Treatments ◽  
Oxygen Precipitation ◽  
Predominant Factor

ABSTRACTWe investigated the effect of D-defect in CZ silicon single crystals on the oxygen precipitation by two-step thermal treatments consisting of the first annealing in nitrogen ambient at 1073K and the second annealing in dry oxygen ambient at 1273K. The density of D-defect was measured by counting ‘flow patterns’ using an optical microscope after preferential etching in Secco's solution for 30 minutes. It was found that the amount of oxygen precipitation along the growth axis was not affected by D-defect. The predominant factor of the oxygen precipitation after the two-step thermal process is the nuclei of oxygen precipitation generated around 723K during CZ crystal growth.

The behaviour of the paramagnetic ions in the single crystals of some similar salts of the iron group of elements I. Hydrated cupric salts

1957 ◽  
Vol 239 (1217) ◽  
pp. 165-183 ◽  
Keyword(s):  
Thermal Expansion ◽  
Single Crystals ◽  
High Frequency ◽  
Relative Orientation ◽  
The Other ◽  
Spin Interaction ◽  
Iron Group ◽  
Double Salts ◽  
Paramagnetic Ions ◽  
The One

The anisotropic behaviours of a series of similarly constituted salts of the Cu 2+ ion have been compared by accurate methods of observation developed in this laboratory. It is found that the principal magnetic axes of the crystal and the relative orientation of the Cu 2+ ion in the unit cell change in most cases, in a few cases abnormally, owing to the anisotropic thermal expansion of the lattice. The thermal magnetic anisotropy behaviour of the Cu 2+ ion in most of the salts may be well represented in the form K 1 - K ┴ . Because of the degeneracy of the spin levels (except for very small spin interaction effects) in Cu 2+ ion, C / T 2 obviously arises in our range of temperatures mainly from a temperature-dependence of the theoretical high-frequency and Curie terms. Abnormalities in the values of the A and B terms also point to the same conclusion. The predominant B term is different from salt to salt and very markedly so between the alkali double salts on the one hand and ammonium and thallium double salts on the other. The tetragonal level separation in different salts and its variation with temperature are discussed.

SINGLE CRYSTAL GROWTH OF HIGH TEMPERATURE SUPERCONDUCTORS AND INVESTIGATION OF THEIR PHYSICAL PROPERTIES

1989 ◽  
Vol 03 (02) ◽  
pp. 289-302 ◽  
Author(s):  
V. A. TATARCHENKO ◽  
G. A. EMEL'CHENKO ◽  
N. V. ABROSIMOV ◽  
V. A. BORODIN ◽  
L. Ya. VINNIKOV ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Optical Properties ◽  
Crystal Growth ◽  
High Temperature ◽  
Thermal Treatment ◽  
Physical Properties ◽  
Single Crystals ◽  
High Temperature Superconductors ◽  
Single Crystal Growth ◽  
Superconducting Properties

Part of the phase diagram of the La 2 O 3- CuO system has been studied and single crystals of La 2 CuO 4, (LaSr) 2 CuO 4 (up to 20 × 8 × 6 mm 3), YBa 2 Cu 3 O 7−δ (up to 8 × 6 × 0.1 mm 3) and HoBa 2 Cu 3 O 7-(up to 3 × 2.5 × 1 mm 3) have been grown by the method of spontaneous crystallisation, using a rotational crucible. It has been established that thermal treatment of "123" single crystals under oxygen pressure to 10 bars improves their superconducting properties. Electrical, magnetic, optical properties, and the real structure of the single crystals produced have been studied.

The study of crystal growth with the electron microscope II. The observation of growth steps in the paraffin n -hectane

1952 ◽  
Vol 214 (1116) ◽  
pp. 72-79 ◽  
Keyword(s):  
Electron Microscope ◽  
Crystal Growth ◽  
Twin Boundary ◽  
Growth Mechanism ◽  
The Other ◽  
Spiral Growth ◽  
Growth Mechanisms ◽  
Slow Evaporation ◽  
Orthorhombic Cell ◽  
The One

Examination of the paraffin n -hectane in the electron microscope has given evidence of two different growth mechanisms for crystals of this compound. The one corresponds to the spiral growth mechanism already observed for n -hexatriacontane (Dawson & Vand 1951), and the orthorhombic lozenge-shaped crystals of n -hectane show the typical spiral growth steps already described. The other growth mechanism gives rise to lath-shaped crystals and operates when growth takes place by the slow evaporation of a cold solution of n -hectane in xylene. The laths are invariably twinned across the diagonal of the orthorhombic cell, and growth in one direction is greatly accelerated by the occurrence of an indestructible step at the twin boundary.

Characterization of Interstitial Oxygen Striations in Silicon Single Crystals by the Micro-FT-IR Method

1993 ◽  
Vol 47 (9) ◽  
pp. 1488-1491 ◽  
Author(s):  
Eiichi Uno ◽  
Izumi Fusegawa ◽  
Hirotoshi Yamagishi
Keyword(s):  
Crystal Growth ◽  
Thermal Treatment ◽  
Single Crystals ◽  
Growth Conditions ◽  
Interstitial Oxygen ◽  
Space Resolution ◽  
Mapping System ◽  
Ft Ir ◽  
High Space

We will demonstrate that our micro-FT-IR mapping system is highly effective for investigating the behavior of interstitial oxygen (Oi) in Czochralski-grown silicon single crystals. The micro-FT-IR system experiences high space resolution, and Oi striations of as-grown silicon single crystals or of oxygen micro-precipitation after a thermal treatment are quantitatively measured. Oi micro-distribution profiles of as-grown crystals exhibit regular or irregular intervals and height, depending upon their crystal growth conditions. Oxygen micro-precipitations along growth striations are dependent upon their initial Oi micro-distribution profiles, and anomalous oxygen micro-precipitation is not observed.

Formation of Nd1+x (Ba1−ySry)2−x Cu3O7±δ solid solutions by crystal pulling

2001 ◽  
Vol 16 (2) ◽  
pp. 529-533 ◽  
Author(s):  
Xin Yao ◽  
E. A. Goodilin ◽  
Teruo Izumi ◽  
Yuh Shiohara
Keyword(s):  
Crystal Growth ◽  
Single Crystals ◽  
Solid Solutions ◽  
Liquid Composition ◽  
The Other ◽  
Composition Control ◽  
Structure Control ◽  
Structure Relation ◽  
Rich Liquid ◽  
Nd Substitution

With the addition of Sr into the NdO1.5–BaO–CuOz flux, series single crystals of Nd1+x (Ba1−ySry)2−x Cu3O7±δ solid solutions (Nd1113ss) were successfully grown by crystal pulling. The liquid composition control was of key importance for controlling the crystal composition, which led to a fundamental structure control. The tetragonal Nd1113ss structure was readily obtained, using a Ba-poor liquid, due to a higher Sr liquid solubility, or using a liquid with the Ba/Cu ratio around 0.33. On the other hand, a Ba-rich liquid could effectively suppress the Nd substitution at Ba sites. The higher Sr addition for achieving a stoichiometric Nd1113 compound was thermodynamically prohibited by (i) an inherently low Sr liquid solubility and (ii) the formation of BaSrCu2Oz phase in the flux at the temperature range for crystal growth. The liquid-solid-structure relation was studied.

Influence of Impurities in SiC Powder on High Quality SiC Crystal Growth

2016 ◽  
Vol 858 ◽  
pp. 85-88
Author(s):  
S. Heo ◽  
H.R. Son ◽  
Byung Sook Kim ◽  
M.S. Kim ◽  
J.E. Han ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Single Crystals ◽  
Carbothermal Reduction ◽  
Impurity Content ◽  
The Other ◽  
High Quality ◽  
Other Hand ◽  
Traditional Process ◽  
Influence Of Impurities

SiC powders having different purities were prepared by carbothermal reduction under different conditions from traditional process and SiC single crystals were grown by the PVT method from the powders. After crystal growth, boule was cut to wafers and they were polished for chemical and defect analyses. Total impurities including Al, B and Ti which were derived from powders decreased remarkably during crystal growth. The formation of defects including micropipe and dislocations such as TED, TSD and BPD was strongly influenced by impurity content. The effect of impurity seemed to be negligible at below 1ppm level for MPD. On the other hand, dislocations continuously decreased even more when higher purity SiC powder below 1ppm level was used.

Seeded Crystal Growth of Yba2Cu3O6.5 in Semisolid Melts

1997 ◽  
Vol 12 (4) ◽  
pp. 880-890 ◽  
Author(s):  
S. Honjo ◽  
M. J. Cima ◽  
M. C. Flemings ◽  
T. Ohkuma ◽  
H. Shen ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Single Crystal ◽  
Single Crystals ◽  
Particle Concentration ◽  
Volume Fraction ◽  
Isothermal Solidification ◽  
The Other ◽  
Oxide Content ◽  
Particle Segregation ◽  
Crystal Interface

Melt textured single crystals of YBa2Cu3O6.5 (123) superconductors were produced by isothermal solidification from a semisolid melt using single crystal NdBa2Cu3O6.5 or SmBa2Cu3O6.5 seeds. The microstructure within the single crystals shows an inhomogeneous segregation of Y2BaCO5 (211) particles trapped in the 123 crystals during solidification. The concentration of 211 particles varies with the crystal axes in 123 crystals produced from precursors with compositions of 80 wt.% 123 powder and 20 wt.% excess 211. The 211 particle concentration along the c-axis in the crystal is much lower than that along the a- or b-axes during initial crystallization. This concentration increases in both directions as the crystal grows larger. The 211 concentration along the c-axis increases more quickly than the concentration along the other axes during solidification, which allows the 211 concentration to approach that on the other axes as the solidification continues. 211 particle segregation in stoichiometric 123 samples formed “X”-shaped tracks instead of the variations in 211 concentration described above. A single crystal growth model of 123 is proposed and employed to interpret these experimental observations. Quenched samples were prepared to investigate the volume fraction of 211 particles in the liquid phase. A constant distribution of 211 particles was observed in the liquid, except very near the crystal interface, where the 211 concentration decreased rapidly. Copper oxide content in the liquid was also measured. It is found that the copper content is lower at the (001) interface compared with (100) or (010) interfaces.

Note on Selection of Coordinate Systems for Geodynamics

1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen
Keyword(s):  
Sea Level ◽  
The Other ◽  
Coordinate Systems ◽  
Mean Sea Level ◽  
The Earth ◽  
The One ◽  
Static Systems ◽  
Selection Of

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.

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