The Influence of Point Defects on Diffusion and Gettering in Silicon

1984 ◽  
Vol 36 ◽  
Author(s):  
U. Gösele ◽  
T. Y. Tan
Keyword(s):  
Point Defects ◽  
Thermal Equilibrium ◽  
Nucleation And Growth ◽  
Impurity Diffusion ◽  
Intrinsic Point Defects ◽  
Different Types ◽  
Equilibrium Concentrations ◽  
Metallic Impurities

ABSTRACTIn a first part, we deal with the influence of intrinsic point defects (vacancies and self-interstitials) on self- and impurity diffusion in silicon. Estimates of the diffusivities and thermal equilibrium concentrations of vacancies and self-interstitials are given. In a second partwe discuss the influence of point defects on the diffusion and precipitation of different types of metallic impurities in various gettering schemes as well as on the nucleation and growth of SiO2 precipitates.

Atomistic Simulations of Point Defect Properties in Silicon

1992 ◽  
Vol 278 ◽  
Author(s):  
Dimitrios Maroudas ◽  
Robert A. Brown
Keyword(s):  
Distribution Function ◽  
Point Defects ◽  
Thermal Equilibrium ◽  
Harmonic Approximation ◽  
Reference State ◽  
Atomistic Simulations ◽  
Free Energies ◽  
Systematic Analysis ◽  
Equilibrium Concentrations ◽  
Cumulant Analysis

AbstractA systematic analysis based on atomistic simulations is presented for the calculation of energies and equilibrium concentrations of intrinsic point defects in silicon. Calculation of Gibbs free energies is based on the quasi-harmonic approximation for the reference state and the cumulant analysis of the enthalpy distribution function from Monte Carlo simulations in the reference state. Results are presented for the temperature dependence of enthalpies, volumes, and free energies of formation and thermal equilibrium concentrations of vacancies and self-interstitials.

scholarly journals Diffusion Engineering by Carbon in Silicon

2000 ◽  
Vol 610 ◽  
Author(s):  
Ulrich Goesele ◽  
Pierre Laveant ◽  
Rene Scholz ◽  
Norbert Engler ◽  
Peter Werner
Keyword(s):  
Point Defects ◽  
Crystalline Silicon ◽  
Bipolar Transistor ◽  
Precipitation Behavior ◽  
High Concentration ◽  
Intrinsic Point Defects ◽  
Influence Diffusion ◽  
Carbon Precipitation ◽  
Equilibrium Concentrations ◽  
Diffusion Mechanisms

AbstractThe possibility to suppress undesirable diffusion of the base dopant boron in siliconbased bipolar transistor structures by the incorporation of a high concentration of carbon has lead to renewed interest in the behavior of carbon in crystalline silicon. The present paper will review essential features of carbon in silicon including solubility, diffusion mechanisms and precipitation behavior. Based on this information the possibilities to use carbon to influence diffusion of dopants in silicon by the introduction of non-equilibrium concentrations of intrinsic point defects will be discussed as well as the reason for the relatively high resilience against carbon precipitation. Interactions between carbon and oxygen will be mentioned, especially in the context of an as yet unexplained fast out-diffusion of carbon close to the surface.

Intrinsic Point Defects and Diffusion Processes in Silicon

1983 ◽  
Vol 31 ◽  
Author(s):  
T. Y. Tan
Keyword(s):  
Point Defects ◽  
Thermal Equilibrium ◽  
Diffusion Processes ◽  
Equilibrium Concentration ◽  
Surface Oxidation ◽  
Self Diffusion ◽  
Equilibrium Concentrations ◽  
And Diffusion

ABSTRACTThis paper reviews recent progress in understanding the role of vacancies (V) and self-interstitials (I) in self and impurity diffusion in Si. Surface oxidation perturbs the thermal equilibrium concentration of point defects and analyses of the resulting effects on dopant diffusion showed that both V and I are present. Developments in experimental and theoretical works on Au diffusion in Si yielded a determination of the I-component and an estimate of the V-component of the Si self-diffusion coefficient. It is hoped that the I and V thermal equilibrium concentrations may be determined in the near future.A number of important physical aspects of the anomalous diffusion of P are now understood but a basically satisfactory model may need further work.

Intrinsic Point Defects in Silicon: a Unified View from Crystal Growth, Wafer Processing and Metal Diffusion

2005 ◽  
Vol 108-109 ◽  
pp. 1-10 ◽  
Author(s):  
Vladimir V. Voronkov ◽  
Robert J. Falster
Keyword(s):  
Temperature Dependence ◽  
Point Defects ◽  
Strong Temperature Dependence ◽  
Depth Profiles ◽  
Intrinsic Point Defects ◽  
Self Diffusion ◽  
Metal Diffusion ◽  
Unified View ◽  
Equilibrium Concentrations ◽  
Wafer Processing

There are several phenomena where the properties of vacancies and self-interstitials in silicon are manifested in straightforward ways. These include the formation of grown-in microdefects, the diffusion of metals (such as Au, Zn), self-diffusion and the installation of vacancy depth profiles in wafers by Rapid Thermal Annealing. Combining features extracted from the analysis of these phenomena, it is possible to define the diffusivities and equilibrium concentrations of the intrinsic point defects. Their diffusivities are remarkably high, and have weak temperature dependence. Their equilibrium concentrations are very low, and have strong temperature dependence.

Crystal structure images of large gold clusters and growing crystals by HRTEM

1984 ◽  
Vol 42 ◽  
pp. 428-429
Author(s):  
L.R. Wallenberg ◽  
J.-O. Bovin ◽  
G. Schmid
Keyword(s):  
Crystal Structure ◽  
Nucleation And Growth ◽  
Close Packing ◽  
Gold Clusters ◽  
Molecular Weight Determination ◽  
Growth Mechanisms ◽  
Starting Point ◽  
Different Types ◽  
Nucleation And Growth Mechanisms ◽  
Points Of View

Metallic clusters are interesting from various points of view, e.g. as a mean of spreading expensive catalysts on a support, or following heterogeneous and homogeneous catalytic events. It is also possible to study nucleation and growth mechanisms for crystals with the cluster as known starting point.Gold-clusters containing 55 atoms were manufactured by reducing (C6H5)3PAuCl with B2H6 in benzene. The chemical composition was found to be Au9.2[P(C6H5)3]2Cl. Molecular-weight determination by means of an ultracentrifuge gave the formula Au55[P(C6H5)3]Cl6 A model was proposed from Mössbauer spectra by Schmid et al. with cubic close-packing of the 55 gold atoms in a cubeoctahedron as shown in Fig 1. The cluster is almost completely isolated from the surroundings by the twelve triphenylphosphane groups situated in each corner, and the chlorine atoms on the centre of the 3x3 square surfaces. This gives four groups of gold atoms, depending on the different types of surrounding.

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