Proximity Gettering of Slow Diffuser Contaminants

2013 ◽  
Vol 205-206 ◽  
pp. 271-277 ◽  
Author(s):  
Maria Luisa Polignano ◽  
Isabella Mica ◽  
Elena Cazzini ◽  
Monica Ceresoli ◽  
Davide Codegoni ◽  
...  
Keyword(s):  
Solid Solution ◽  
Impurity Concentration ◽  
Extended Defects ◽  
High Impurity ◽  
High Impurity Concentration ◽  
Silicon Implantation ◽  
And Tungsten

In this paper, we test proximity gettering layers obtained by carbon or silicon implantation for their efficiency in molybdenum and tungsten gettering. DLTS was used to measure the impurity concentration in the solid solution and so to evaluate gettering efficiency. It was found that carbon implantation is effective in capturing these impurities, whereas silicon implantation is not. Extended defects seem not to play an important role in gettering these impurities. In addition, gettering was found to be most effective at high impurity concentration.

scholarly journals Fabrication of non-equilibrium Si: Te and Si: Zn Systems with extremely high impurity concentration by means of laser annealing.

1981 ◽  
Vol 9 (4) ◽  
pp. 434-438
Author(s):  
Kouichi MURAKAMI ◽  
Eiji IKAWA ◽  
A.H. ORABY ◽  
Kenji GAMO ◽  
Susumu NAMBA ◽  
...  
Keyword(s):  
Impurity Concentration ◽  
Laser Annealing ◽  
High Impurity ◽  
High Impurity Concentration ◽  
Non Equilibrium

Resistivity Distribution Characteristics of Metallurgical Silicon Ingot after Directional Solidification

2011 ◽  
Vol 675-677 ◽  
pp. 109-112
Author(s):  
Shu Ang Shi ◽  
Wei Dong ◽  
Shi Hai Sun ◽  
Yi Tan ◽  
Guo Bin Li ◽  
...  
Keyword(s):  
Directional Solidification ◽  
Vertical Section ◽  
Growth Direction ◽  
Silicon Ingot ◽  
Metallurgical Silicon ◽  
High Impurity ◽  
Polarity Transition ◽  
High Impurity Concentration ◽  
Solid Liquid Interface ◽  
Solid Liquid

The distribution of resistivity, impurity and polarity in multicrystalline silicon ingot prepared by directional solidification method was detected. The effect of impurity distribution on resistivity was also researched. The results show that the shapes of equivalence line of resistivity in the cross section and vertical section of the silicon ingot depend on the solid-liquid interface. The resistivity in the vertical section increases with the increasing of solidified height at the beginning of solidification and reaches to maximum at the polarity transition point, then decreases rapidly with the increasing of solidified height and tends to zero on the top of the ingot because of the high impurity concentration. Study proves that the variation of resistivity in the vertical section is mainly relevant to the concentration distribution of the impurities such as Al, B and P in the growth direction.

Constituent Diffusion in a Deformable Thermoelastic Solid

1987 ◽  
Vol 54 (2) ◽  
pp. 441-446 ◽  
Author(s):  
S. P. Girrens ◽  
F. W. Smith
Keyword(s):  
Thermal Loading ◽  
Diffusion Theory ◽  
Parent Material ◽  
Β Phase ◽  
High Impurity ◽  
High Impurity Concentration ◽  
Thermoelastic Solid ◽  
Impurity Elements ◽  
Fully Coupled ◽  
Diffusion Problems

Solid mixtures containing initially uniform dilute concentrations of impurity elements may, upon the application of mechanical and thermal loading, develop regions of high impurity concentration that could result in local degradation of material properties. To address these degradation processes, a fully coupled thermomechanical-diffusion theory has been developed to describe the mass transport of mobile constituents driven by gradients in concentration, strain dilatation and temperature in a solid deformable parent material. A finite element code has been assembled to solve plane transient thermomechanical-diffusion problems. The theory presented and the resulting code have been successfully used to model internal hydrogen redistribution in β-phase Ti alloys induced by elastic strain gradients during bending.

Crystalline structure of Ba2YCu0.25W0.75O6: A member of the new set of Ba2YzCuxW1−xO6 solid solutions

1996 ◽  
Vol 11 (1) ◽  
pp. 42-44 ◽  
Author(s):  
Bokhimi ◽  
A. Morales ◽  
A. Garci´a-Ruiz
Keyword(s):  
Solid Solution ◽  
Crystalline Structure ◽  
Solid Solutions ◽  
Local Environment ◽  
Unit Cell ◽  
Ordered Structure ◽  
Space Group ◽  
First Approximation ◽  
And Tungsten

A model for the crystalline structure of Ba2YCu0.25W0.75O6 solid solution is given. The model proposed a perovskite ordered structure, with a cubic unit cell made from eight perovskite-like units and having a symmetry described by the space group Fm3m. The crystalline structure was refined by the Rietveld technique, giving RF=0.048 for 82 reflections. The solid solution was characterized by the following parameters: Z=4, Mr=613.2, a=8.43630(8) Å, V=600.42(1) Å3, Dx=6.78 g cm−3, μ=209.04 mm−1, and F(000)=1047. The model assumed that copper and tungsten atoms, which were ordered with Y atoms, had the same local environment. Therefore, it was only a first approximation to the crystalline structure.

The Extended Defect as a Mechanism for the Immobilization of HLW Species in Zirconolite, Perovskite and Hollandite

1985 ◽  
Vol 50 ◽  
Author(s):  
T. J. White
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Continuous Solid Solution ◽  
Analytical Electron Microscopy ◽  
Glass Ceramics ◽  
High Resolution Electron Microscopy ◽  
High Level Waste ◽  
Isomorphic Substitution ◽  
Extended Defects ◽  
Extended Defect

AbstractHigh resolution electron microscopy, analytical electron microscopy and selected area electron diffraction are used to establish the crystallochemical mechanisms by which simulated high level waste enters Synroc. It is shown that waste species are incorporated largely as a non-continuous solid solution. In other words, simple isomorphic substitution of waste elements in place of matrix cations, i.e. the classical continuous solid solution, does not operate (or is only significant at very low waste levels of radwaste). Usually, substitution is accompanied by the appearance of coherent extended defects which can take the form of antiphase boundaries, unit cell twinning (both mimetic and polysynthetic), or cation ordering. In this manner, a numb~er of closely related phases appear in response to variations in waste composition and loading. It is believed that the mechanism of structural modification will endow Synroc with considerable flexibility to respond to chemical changes in the wastestream. Other ceramic materials currently being evaluated as possible wasteforms (viz. sphene glass-ceramics and APO4 phosphates), are also likely to possess this capacity.

Silicon interstitial absorption during thermal oxidation at 900 °C by extended defects formed via silicon implantation

1993 ◽  
Vol 62 (20) ◽  
pp. 2498-2500 ◽  
Author(s):  
David J. Roth ◽  
Robert Y. S. Huang ◽  
James D. Plummer ◽  
Robert W. Dutton
Keyword(s):  
Thermal Oxidation ◽  
Extended Defects ◽  
Silicon Implantation ◽  
Interstitial Absorption
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