From the Mystery to the Understanding of the Self-Interstitials in Silicon

1980 ◽  
Vol 2 ◽  
Author(s):  
W. Frank ◽  
A. Seeger ◽  
U. Gösele
Keyword(s):  
High Temperature ◽  
The Self ◽  
Experimental Conditions ◽  
Group V ◽  
Group Iii ◽  
Enhanced Diffusion ◽  
Self Diffusion ◽  
Thermally Activated ◽  
Temperature Equilibrium ◽  
K Concentration

ABSTRACTOur present knowledge on self-interstitials in silicon and the rôle these defects play under widely different experimental conditions are surveyed. In particular, the following phenomena involving self-interstitials either in supersaturations or under high-temperature thermal-equilibrium conditions are considered: mobility-enhanced diffusion of self-interstitials below liquid-helium temperature, thermally activated diffusion of self-interstitials at inter-mediate temperatures (14O K to 600 K), concentration-enhanced diffusion of Group-III or Group-V elements in silicon at higher temperatures, and— as examples for high-temperature equilibrium phenomena — self-diffusion and diffusion of gold in silicon. This leads to the picture that the self-interstitials in silicon may occur in different electrical charge states and possess dumbbell configurations or are extended over several atomic volumes at intermediate or high temperatures, respectively.

High temperature oxidation of ion-plated CrN films

1994 ◽  
Vol 9 (1) ◽  
pp. 151-155 ◽  
Author(s):  
Hiroshi Ichimura ◽  
Atsuo Kawana
Keyword(s):  
High Temperature ◽  
High Temperature Oxidation ◽  
Mass Gain ◽  
The Self ◽  
Temperature Oxidation ◽  
Outward Diffusion ◽  
Ion Plating ◽  
Self Diffusion ◽  
Steel Substrates ◽  
Self Diffusion Coefficient

The high-temperature oxidation of CrN films which were deposited onto stainless steel substrates using an arc ion plating apparatus was studied at temperatures ranging from 1023 to 1173 K for 0.6 to 480 ks in air. The oxidation rate obtained from mass gain as a function of time was found to fit well to a parabolic time dependence. Formed oxide layers were analyzed by XRD, SEM, and SAM. An activation energy of the oxidation of CrN was slightly lower than that of the self-diffusion coefficient of Cr ion in Cr2O3. It is concluded that the oxidation of CrN is controlled by the outward diffusion of Cr ions through the Cr2O3 layer formed on each CrN grain.

Enhanced Diffusion of High-Temperature Implanted Aluminum in Silicon Carbide

1995 ◽  
Vol 396 ◽  
Author(s):  
A V. Suvorov ◽  
I.O. Usov ◽  
V.V. Sokolov ◽  
A.A. Suvorova
Keyword(s):  
Silicon Carbide ◽  
Diffusion Coefficient ◽  
High Temperature ◽  
Secondary Ion Mass Spectrometry ◽  
Near Surface ◽  
Enhanced Diffusion ◽  
Thermally Activated ◽  
Transmission Electron ◽  
Radiation Enhanced Diffusion ◽  
Sic Wafer

AbstractThe diffusion of aluminum in silicon carbide during high-temperature A1+ ion implantation was studied using secondary ion mass spectrometry (SIMS). Transmission electron microscopy (TEM) has been used to determine the microstructure of the implanted sample. A 6H-SiC wafer was implanted at a temperature of 1800 °C with 40 keV Al ions to a dose of 2 x 1016 cm-2. It was established that an Al step-like profile starts at the interface between the crystal region and the damaged layer. The radiation enhanced diffusion coefficient of Al at the interface was determined to be Di = 2.8 x 10-12 cm2/s, about two orders of magnitude higher than the thermally activated diffusion coefficient. The Si vacancy-rich near-surface layer formed by this implantation condition is believed to play a significant role in enhanced Al diffusion.

Self-Diffusion in Gold

1971 ◽  
Vol 49 (21) ◽  
pp. 2704-2709 ◽  
Author(s):  
H. M. Morrison ◽  
Virginia L. S. Yuen
Keyword(s):  
High Temperature ◽  
Diffusion Coefficients ◽  
Temperature Behavior ◽  
Enhanced Diffusion ◽  
Temperature Range ◽  
High Temperature Behavior ◽  
Self Diffusion ◽  
Lower Temperature

An electrolytic sectioning technique has been used to measure self-diffusion coefficients for gold in the temperature range 360 to 740 °C. At 740 °C our value agrees with previous work at this temperature, while the lower temperature values are larger than predicted by extrapolation of the well-established high-temperature behavior. The results are interpreted in terms of dislocation enhanced diffusion.

Icosahedral Boron-Rich Solids as Refractory Semiconductors

1987 ◽  
Vol 97 ◽  
Author(s):  
David Emin
Keyword(s):  
High Temperature ◽  
Seebeck Coefficient ◽  
Basic Structure ◽  
Group Iv ◽  
Group Vi ◽  
Group V ◽  
Thermally Activated ◽  
Distinctive Structure ◽  
Wide Gap ◽  
P Type

ABSTRACTIcosahedral boron-rich solids are refractory materials composed of twelve-atom boron-rich icosahedral units with strong intericosahedral linkages. These distinctive structures admit unusual electronic and thermal transport properties. Here the distinctive (three-center) bonding which underlies these materials is first described. Then it is shown how insulators, semiconductors and highly degenerate (metal-like) materials emerge from the same basic structure with appropriate substitutions.The electronic transport of the boron carbides is then addressed. The boron carbides are degenerate p-type semiconductors in which the charge carriers are diamagnetically aligned pairs of electrons which hop between icosahedra. Uniquely, this thermally activated hopping conductivity increases with increasing hydrostatic pressure. However, the Seebeck coefficient (thermoelectric power) is uncharacteristic of a degenerate semiconductor. Namely, the Seebeck coefficient is typically both large and an increasing function of temperature. In addition, despite the hardness and refractory character of these materials, their thermal conductivities can be surprisingly low with a glass-like temperature dependence. These features are manifestations of the distinctive structure and bonding of these solids. In fact, this novel mix of properties makes the boron carbides exceptionally good very-high-temperature p-type thermoelectric materials.Icosahedral boron-rich solids have additional potential as high temperature semiconductors. In particular, the wide-gap icosahedral boronrich pnictides, B12P2 and B12As2, may be doped to form wide-gap refractory semiconductors. For example, replacement of the group V element with either a group VI or a group IV element is expected to yield n-type and ptype material, respectively.

The Nature of Point Defects and their Influence on Diffusion Processes in Silicon at High Temperatures

1982 ◽  
Vol 14 ◽  
Author(s):  
U. GÖsele ◽  
T.Y. Tan
Keyword(s):  
Diffusion Processes ◽  
Surface Oxidation ◽  
Group V ◽  
Group Iii ◽  
Self Diffusion ◽  
Slowing Down ◽  
Silicon Crystals ◽  
Order Of Magnitude ◽  
Theoretical Results

ABSTRACTThe paper highlights recent progress in understanding the role of vacancies and self-interstitials in self- and impurity diffusion in silicon above about 700°C. How surface oxidation of silicon leads to a perturbation of the pointdefect population is described. An analysis of the resulting oxidationenhanced or -retarded diffusion of group III and group V dopants shows that under thermal equilibrium as well as under oxidation conditions both vacancies and self-interstitials are present. For sufficiently long times vacancies and self-interstitials attain dynamical equilibrium which involves their recombination and spontaneous thermal creation in the bulk of silicon crystals. The existence and the nature of a recombination barrier slowing down the recombination process are discussed in this context. Recent experimental and theoretical results on the diffusion of gold in silicon enable us to determine the selfinterstitial component of silicon self-diffusion and to obtain an estimate of the respective vacancy contribution. The two components turn out to be of the same order of magnitude from 700°C up to the melting point.

A Model for Boron T.E.D. in Silicon: Full Couplings of Dopant with Free and Clustered Interstitials

2002 ◽  
Vol 717 ◽  
Author(s):  
F. Boucard ◽  
D. Mathiot ◽  
E. Guichard ◽  
P. Rivallin
Keyword(s):  
Point Defects ◽  
Diffusion Mechanism ◽  
Low Energy ◽  
The Self ◽  
Large Set ◽  
Dopant Diffusion ◽  
Experimental Conditions ◽  
Enhanced Diffusion ◽  
Equilibrium Reactions ◽  
Fully Coupled

AbstractIn this contribution we present a model for transient enhanced diffusion of boron in silicon. This model is based on the usual pair diffusion mechanism including non-equilibrium reactions between the dopant and the free point defects, taking into account their various charge states. In addition to, and fully coupled with the dopant diffusion we model the growth and dissolution of the interstitials and boron interstitials clusters associated with the anneal of the self-interstitial supersaturation created by the implantation step. It is thus possible to simulate a rather large set of experimental conditions, from conventional predeposition steps, to RTA after low energy implantation.

Formation of stable dopant interstitials during ion implantation of silicon

1986 ◽  
Vol 1 (3) ◽  
pp. 476-492 ◽  
Author(s):  
S.J. Pennycook ◽  
R.J. Culbertson ◽  
J. Narayan
Keyword(s):  
Ion Implantation ◽  
Direct Evidence ◽  
Solid Phase ◽  
Diffusion Mechanism ◽  
Transient Effects ◽  
Group V ◽  
Group Iii ◽  
Enhanced Diffusion ◽  
High Concentrations ◽  
Dopant Atoms

High concentrations of self-interstitials are trapped by dopant atoms during ion implantation into Si. For group V dopants, these complexes are sufficiently stable to survive solid-phase-epitaxial (SPE) growth but break up on subsequent thermal processing and cause a transientenhanced diffusion. Dopant diffusion coefficients are enhanced by up to five orders of magnitude over tracer values and are characterized by an activation energy of approximately one half of the tracer values. In the case of group III dopants, any complexes formed during implantation do not survive SPE growth but a second source of self-interstitials becomes significant and leads to similar transient effects. This is the damaged layer underlying the original amorphous/crystalline interface. These observations provide direct evidence for longrange self-interstitial migration in Si, and we believe these are the first observations of the interstitialcy diffusion mechanism with no vacancy contribution. We propose that the complexes are simply interstitial dopant atoms (in a split <100> interstitialcy configuration) that are particularly stable in the case of group V dopants. As they decay self-interstitials are released and cause the transient-enhanced diffusion.

The Quantitative Ultrastructure of the Heart Muscle of Japanese Quail by Hypergravitation, Hypodynamy and Combination

1990 ◽  
Vol 48 (3) ◽  
pp. 188-189
Author(s):  
Anton Bózner ◽  
Mikuláš Gažo ◽  
Jozef Dostál
Keyword(s):  
Japanese Quail ◽  
Heart Muscle ◽  
Relative Size ◽  
Combination Group ◽  
Control Group ◽  
Group V ◽  
Group Iii ◽  
Space Flights ◽  
Group I ◽  
Quantitative Ultrastructure

It is anticipated that Japanese quail /Coturnix coturnix japonica/ will provide animal proteins in long term space flights. Consequently this species of birds is of research interest of international space program INTERCOSMOS. In the year 1987 we reported on an experiment /2/ in which the effect of chronic acceleration of 2 G hypergravitation, the hypodynamy and the simultaneous effect of chronic acceleration and the location in the centre of the turntable of the centrifuge on the protein fractions in skeletal muscles was studied. The ultrastructure of the heart muscle was now in this experiments examined as well.Japanese quail cockerels, aged 48 days were exposed to 2 G hypergravitation /group IV/ in a 6,4 m diameter centrifuge, to hypodynamy /group III/ and their combination /group V/, respectively for 6 days / Fig.1/. The hypodynamy in group III was achieved by suspending the birds in jackets without contact the floor. The group II was located in the centre ofthe turntable of the centrifuge. The control group I. was kept under normal conditions. The quantitative ultrastructure of myocard was evaluated by the methods of Weibel/3/ - this enables to determine the number, relative size and volume of mitochondria volume of single mitochondria, defficiency of mitochondrial cristae and volume of myofibrils.

STEREOTYPE THREAT AND STEREOTYPE LIFT: THE CASE OF 10 YEAR OLD GIRLS AND BOYS

2016 ◽  
Vol 12 (4) ◽  
pp. 21-32
Author(s):  
Anna Kwiatkowska ◽  
Małgorzata Mróz
Keyword(s):  
Stereotype Threat ◽  
Cognitive Performance ◽  
Significant Interaction ◽  
Self Esteem ◽  
The Self ◽  
Experimental Conditions ◽  
Significant Interaction Effect ◽  
Significant Drop ◽  
Stereotype Lift ◽  
And Performance

The aim of this study was to examine the effects of stereotypical and counter-stereotypicalinformation on the self-esteem and cognitive performance of 10-year-old children. Our sampleconsisted of 37 girls and 37 boys. Children were presented with 10 “mathematical” puzzles in threeexperimental conditions: stereotypical (boys are better), counter-stereotypical (girls are better), andthe control condition (no particular information). Self-esteem was measured using a non-verbaltask. The results showed a significant interaction effect of “condition x sex” on self-esteem andperformance. Girls revealed no significant differences between control and experimental conditions,while boys showed a significant drop in self-esteem and performance in the counter-stereotypicalcondition as compared to the control condition and a significant lift in self-esteem and performancein the stereotypical condition as compared to the control condition.

Sign in / Sign up

Export Citation Format

Share Document