scholarly journals Effect Of Pressure On Boron Diffusion In Silicon

1996 ◽  
Vol 442 ◽  
Author(s):  
Yuechao Zhao ◽  
Michael J. Aziz ◽  
Salman Mitha ◽  
David Schiferl
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Diffusion Mechanism ◽  
Boron Diffusion ◽  
Effect Of Pressure ◽  
Self Diffusion ◽  
Pressure Medium ◽  
Atomistic Calculations ◽  
Fluid Argon ◽  
Homoepitaxial Layers ◽  
Strained Films

AbstractWe are studying the effect of pressure on boron diffusion in silicon in order to better understand the nature of the point defects responsible for diffusion. Si homoepitaxial layers deltadoped with boron were grown using molecular beam epitaxy. Diffusion anneals were performed in a high temperature diamond anvil cell using fluid argon as a pressure medium. Diffusivities were deduced from B concentration-depth profiles measured with using secondary ion mass spectrometry. Preliminary results indicate that pressure enhances B diffusion in Si at 850 °C, characterized by an average activation volume of -0.125±0.02 times the atomic volume, and thus appear consistent with an interstitial-based diffusion mechanism. Results are compared with previous hydrostatic-pressure studies, with results in biaxially strained films, and with atomistic calculations of activation volumes for self diffusion.

Nonhydrostatic Stress Effects on Boron Diffusion in SI

1997 ◽  
Vol 469 ◽  
Author(s):  
Michael J. Aziz
Keyword(s):  
Hydrostatic Pressure ◽  
Hydrostatic Stress ◽  
Diffusion Mechanism ◽  
Biaxial Stress ◽  
Extended Defects ◽  
Boron Diffusion ◽  
Stress Effects ◽  
Atomistic Calculations ◽  
Strained Films

ABSTRACTThe thermodynamics of diffusion under hydrostatic pressure and nonhydrostatic stress is developed for single crystals free of extended defects and is applied to the case of boron diffusion in silicon. The thermodynamic relationships obtained permit the direct comparison of hydrostatic and biaxial stress experiments and of atomistic calculations under hydrostatic stress. Assuming various values for the anisotropy in the migration strain, a currently unknown parameter, comparison is made between various measurements under hydrostatic pressure and nonhydrostatic stress, and various atomistic calculations of the volumetrics of B and Si diffusion by an interstitial-based mechanism. An independent determination of the anisotropy of the migration strain would permit a parameter-free determination of the predominant diffusion mechanism and would permit the prediction of the ratio of the diffusivity normal to the free surface to the diffusivity parallel to the surface for biaxially strained films. Procedures for measuring and calculating the anisotropy in the migration strain are described.

Modeling of the Boron Emitter Formation Process from BCl3 Diffusion for N-Type Silicon Solar Cells Processing

2011 ◽  
Vol 324 ◽  
pp. 261-264 ◽  
Author(s):  
Jimmy Armand ◽  
Cyril Oliver ◽  
F. Martinez ◽  
B. Semmache ◽  
M. Gauthier ◽  
...  
Keyword(s):  
Solar Cells ◽  
Diffusion Process ◽  
Secondary Ion Mass Spectrometry ◽  
Diffusion Mechanism ◽  
Mass Spectrometry Analysis ◽  
Silicon Solar Cells ◽  
Boron Diffusion ◽  
Chemical Reaction Kinetics ◽  
Spectrometry Analysis ◽  
Type Silicon

This work is devoted to the study of boron doping diffusion process for n-type silicon solar cells applications. Deposition temperature is an important parameter in the diffusion process. In this paper we investigate its influence using an industrial scale furnace [1] (LYDOPTM Boron), which is developed by Semco Engineering. We especially used a numerical model (Sentaurus) in order to further understand the boron diffusion mechanism mainly with respect of the diffusion temperature. The model calibration is based on boron concentration profiles obtained by SIMS (Secondary Ion Mass Spectrometry) analysis. We observed that the boron profiles could be correctly simulated by a single fitting parameter. This parameter, noted kBoron which is connected to the chemical reaction kinetics developed at the interface between the boron silicon glass (BSG) and the silicon substrate

Direct determination of the self-diffusion mechanism in bccβ-titanium

1989 ◽  
Vol 39 (8) ◽  
pp. 5025-5034 ◽  
Author(s):  
G. Vogl ◽  
W. Petry ◽  
Th. Flottmann ◽  
A. Heiming
Keyword(s):  
Diffusion Mechanism ◽  
Direct Determination ◽  
The Self ◽  
Self Diffusion

scholarly journals Transport and Electromechanical Properties of Ca3TaGa3Si2O14 Piezoelectric Crystals at Extreme Temperatures

MRS Advances ◽  
2019 ◽  
Vol 4 (09) ◽  
pp. 515-521
Author(s):  
Yuriy Suhak ◽  
Ward L. Johnson ◽  
Andrei Sotnikov ◽  
Hagen Schmidt ◽  
Holger Fritze
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Tone Burst ◽  
Total Conductivity ◽  
Transport Mechanisms ◽  
Electromechanical Properties ◽  
Self Diffusion ◽  
Oxygen Ion ◽  
Piezoelectric Strain ◽  
Secondary Ion ◽  
Diffusion Profiles

ABSTRACTTransport mechanisms in structurally ordered piezoelectric Ca3TaGa3Si2O14 (CTGS) single crystals are studied in the temperature range of 1000-1300 °C by application of the isotope 18O as a tracer and subsequent analysis of diffusion profiles of this isotope using secondary ion mass spectrometry (SIMS). Determined oxygen self-diffusion coefficients enable calculation of oxygen ion contribution to the total conductivity, which is shown to be small. Since very low contributions of the cations have to be expected, the total conductivity must be dominated by electron transport. Ion and electron conductivities are governed by different mechanisms with activation energies (1.9±0.1) eV and (1.2±0.07) eV, respectively. Further, the electromechanical losses are studied as a function of temperature by means of impedance spectroscopy on samples with electrodes and a contactless tone-burst excitation technique. At temperatures above 650 °C the conductivity-related losses are dominant. Finally, the operation of CTGS resonators is demonstrated at cryogenic temperatures and materials piezoelectric strain constants are determined from 4.2 K to room temperature.

scholarly journals Self- and Dopant Diffusion in Extrinsic Boron Doped Isotopically Controlled Silicon Multilayer Structures

2002 ◽  
Vol 719 ◽  
Author(s):  
Ian D. Sharp ◽  
Hartmut A. Bracht ◽  
Hughes H. Silvestri ◽  
Samuel P. Nicols ◽  
Jeffrey W. Beeman ◽  
...  
Keyword(s):  
Multilayer Structure ◽  
Secondary Ion Mass Spectrometry ◽  
Diffusion Processes ◽  
Quantitative Description ◽  
Multilayer Structures ◽  
Dopant Diffusion ◽  
Enhanced Diffusion ◽  
Self Diffusion ◽  
Boron Doped ◽  
P Type

AbstractIsotopically controlled silicon multilayer structures were used to measure the enhancement of self- and dopant diffusion in extrinsic boron doped silicon. 30Si was used as a tracer through a multilayer structure of alternating natural Si and enriched 28Si layers. Low energy, high resolution secondary ion mass spectrometry (SIMS) allowed for simultaneous measurement of self- and dopant diffusion profiles of samples annealed at temperatures between 850°C and 1100°C. A specially designed ion-implanted amorphous Si surface layer was used as a dopant source to suppress excess defects in the multilayer structure, thereby eliminating transient enhanced diffusion (TED) behavior. Self- and dopant diffusion coefficients, diffusion mechanisms, and native defect charge states were determined from computer-aided modeling, based on differential equations describing the diffusion processes. We present a quantitative description of B diffusion enhanced self-diffusion in silicon and conclude that the diffusion of both B and Si is mainly mediated by neutral and singly positively charged self-interstitials under p-type doping. No significant contribution of vacancies to either B or Si diffusion is observed.

Structural and Mechanical Properties of Nanophase Ni: A Molecular-Dynamics Study of the Influence of Grain-Boundary Structure on Elastic and Plastic Behavior

1997 ◽  
Vol 492 ◽  
Author(s):  
H. Van Swygenhoven ◽  
M. Spaczér ◽  
A. Caro
Keyword(s):  
Molecular Dynamics ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Diffusion Mechanism ◽  
Distribution Functions ◽  
Boundary Structure ◽  
Plastic Behavior ◽  
Self Diffusion ◽  
Common Neighbour ◽  
Grain Boundary Structure

ABSTRACTMolecular dynamics computer simulations of high load plastic deformation at temperatures up to 500K of Ni nanophase samples with mean grain size of 5 nm are reported. Two types of samples are considered: a polycrystal nucleated from different seeds, each having random location and random orientation, representing a sample with mainly high angle grain boundaries, and polycrystals with seeds located at the same places as before, but with a limited missorientation representing samples with mainly low angle grain boundaries. The structure of the grain boundaries is studied by means of pair distribution functions, coordination number, atom energetics, and common neighbour analysis. Plastic behaviour is interpreted in terms of grain-boundary viscosity, controlled by a self diffusion mechanism at the disordered interface activated by thermal energy and stress.

Effect of pressure and temperature of the self-diffusion of water

1974 ◽  
Vol 14 (6) ◽  
pp. 911-914 ◽  
Author(s):  
V. V. Kisel'nik ◽  
N. G. Malyuk ◽  
A. N. Toryanik ◽  
V. M. Toryanik
Keyword(s):  
The Self ◽  
Effect Of Pressure ◽  
Self Diffusion

Lithium tracer diffusion in near stoichiometric LiNi0.5Mn1.5O4 cathode material for lithium-ion batteries

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Daniel Uxa ◽  
Harald Schmidt
Keyword(s):  
Cathode Material ◽  
Secondary Ion Mass Spectrometry ◽  
Lithium Ion ◽  
Tracer Diffusion ◽  
Side Reactions ◽  
Battery Materials ◽  
Self Diffusion ◽  
Thermally Activated ◽  
Average Grain Size ◽  
And Migration

Abstract The compound LiNi0.5Mn1.5O4 is used as novel cathode material for Li-ion batteries and represents a variant to replace conventional LiMn2O4. For a further improvement of battery materials it is necessary to understand kinetic processes at and in electrodes and the underlying diffusion of lithium that directly influences charging/discharging times, maximum capacities, and possible side reactions. In the present study Li tracer self-diffusion is investigated in polycrystalline sintered bulk samples of near stoichiometric LiNi0.5Mn1.5O4 with an average grain size of about 50–70 nm in the temperature range between 250 and 600 °C. For analysis, stable 6Li tracers are used in combination with secondary ion mass spectrometry (SIMS). The tracer diffusivities can be described by the Arrhenius law with an activation enthalpy of (0.97 ± 0.05) eV, which is interpreted as the sum of the formation and migration energy of a thermally activated Li vacancy.

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