Chemistry of Point Defect in Silicon and its Applications in Semiconductor Technology

1995 ◽  
Vol 378 ◽  
Author(s):  
S. Pizzini ◽  
S. Binetti ◽  
M. Acciarri
Keyword(s):  
Point Defects ◽  
Chemical Species ◽  
Semiconductor Technology ◽  
Interaction Processes ◽  
Stable Chemical ◽  
Diffusion Controlled ◽  
Trapping Model ◽  
Boundary Conditions For Diffusion ◽  
Major Attention ◽  
Aggregation Phenomena

AbstractThe chemistry of the interactions between point defects and impurities is discussed by considering first the general thermodynamic and kinetic aspects of these reactions, deserving major attention to the identity of of the stable chemical species eventually formed and to the boundary conditions for diffusion controlled and reaction controlled interaction processes.The second part of the paper is instead dedicated to the analysis of the chemistry of carbon, oxygen, hydrogen and point defects in silicon, which is a system of major technological interest.We postulate that at low enough temperatures, when homogeneous nucleation processes are slow, spinodal decomposition assists oxygen aggregation phenomena. We postulate, also, on the basis of the existing knowledge, that carbon and hydrogen favour alternative reaction paths for oxygen in the due of clustering processes and discuss the hydrogen-enhanced oxygen diffusivity in the frame of a conventional trapping model.

Point Defects in Doped and Undoped Hgl−xCdxTe Alloys

1981 ◽  
Vol 9 ◽  
Author(s):  
H. R. Vydyanath
Keyword(s):  
Point Defects ◽  
Chemical Species ◽  
Lattice Defects ◽  
Mass Action ◽  
Electrical Characteristics ◽  
Law Of Mass Action ◽  
Physicochemical Conditions

EXTENDED ABSTRACTUsing a law of mass action approach in which lattice defects are treated as chemical species, the variation of the defect concentrations as a function of .the physicochemical conditions of preparation has been established via measurements of electrical characteristics which are directly related to the defect concentrations.

Point Defects in SiC

2008 ◽  
Vol 1069 ◽  
Author(s):  
Ádám Gali ◽  
Michel Bockstedte ◽  
Ngyen Tien Son ◽  
Erik Janzén
Keyword(s):  
Silicon Carbide ◽  
Electron Paramagnetic Resonance ◽  
Ab Initio ◽  
Point Defects ◽  
Semiconductor Technology ◽  
Tight Control ◽  
Accurate Calculation ◽  
Paramagnetic Resonance ◽  
Absorption And Emission ◽  
Electron Paramagnetic

ABSTRACTTight control of defects is pivotal for semiconductor technology. However, even the basic defects are not entirely understood in silicon carbide. In the recent years significant advances have been reached in identification of defects by combining the experimental tools like electron paramagnetic resonance and photoluminescence with ab initio calculations. We summarize these results and their consequences in silicon carbide based technology. We show recent methodological developments making possible the accurate calculation of absorption and emission signals of defects.

scholarly journals Recombinant Escherichia coli as a biofactory for various single- and multi-element nanomaterials

2018 ◽  
Vol 115 (23) ◽  
pp. 5944-5949 ◽  
Author(s):  
Yoojin Choi ◽  
Tae Jung Park ◽  
Doh C. Lee ◽  
Sang Yup Lee
Keyword(s):  
Escherichia Coli ◽  
Metal Binding ◽  
Chemical Species ◽  
Cell Extract ◽  
Live Cells ◽  
Biological Synthesis ◽  
Stable Chemical ◽  
Initial Ph

Nanomaterials (NMs) are mostly synthesized by chemical and physical methods, but biological synthesis is also receiving great attention. However, the mechanisms for biological producibility of NMs, crystalline versus amorphous, are not yet understood. Here we report biosynthesis of 60 different NMs by employing a recombinant Escherichia coli strain coexpressing metallothionein, a metal-binding protein, and phytochelatin synthase that synthesizes a metal-binding peptide phytochelatin. Both an in vivo method employing live cells and an in vitro method employing the cell extract are used to synthesize NMs. The periodic table is scanned to select 35 suitable elements, followed by biosynthesis of their NMs. Nine crystalline single-elements of Mn3O4, Fe3O4, Cu2O, Mo, Ag, In(OH)3, SnO2, Te, and Au are synthesized, while the other 16 elements result in biosynthesis of amorphous NMs or no NM synthesis. Producibility and crystallinity of the NMs are analyzed using a Pourbaix diagram that predicts the stable chemical species of each element for NM biosynthesis by varying reduction potential and pH. Based on the analyses, the initial pH of reactions is changed from 6.5 to 7.5, resulting in biosynthesis of various crystalline NMs of those previously amorphous or not-synthesized ones. This strategy is extended to biosynthesize multi-element NMs including CoFe2O4, NiFe2O4, ZnMn2O4, ZnFe2O4, Ag2S, Ag2TeO3, Ag2WO4, Hg3TeO6, PbMoO4, PbWO4, and Pb5(VO4)3OH NMs. The strategy described here allows biosynthesis of NMs with various properties, providing a platform for manufacturing various NMs in an environmentally friendly manner.

Homology of Potential Energy Surfaces

1986 ◽  
Vol 41 (9) ◽  
pp. 1118-1122
Author(s):  
Ariel Fernández
Keyword(s):  
Potential Energy ◽  
Configuration Space ◽  
Potential Energy Surfaces ◽  
Transition States ◽  
Chemical Species ◽  
Basins Of Attraction ◽  
Intrinsic Reaction Coordinate ◽  
Sigmatropic Rearrangements ◽  
Stable Chemical ◽  
Energy Surfaces

It is shown that all the adjacency relations for the basins of attraction of stable chemical species and transition states can be derived from the topology of the pattern of intrinsic-reaction-coordinate- and-separatix trajectories in the nuclear configuration space.The results are applied to thermal [1,3] sigmatropic rearrangements and they show that even the symmetry-forbidden path proceeds concertedly. The corresponding homological formulas giving the adjacency relations are derived.

THE EFFECT OF ALLOYING WITH MAGNESIUM ON THE ANNEALING BEHAVIOR OF ALUMINUM ALLOYS STUDIED BY POSITRON LIFETIME TECHNIQUE

2007 ◽  
Vol 14 (01) ◽  
pp. 43-47
Author(s):  
M. O. ABDEL-HAMED
Keyword(s):  
Plastic Deformation ◽  
Aluminum Alloys ◽  
Point Defects ◽  
Room Temperature ◽  
Positron Lifetime ◽  
Defect State ◽  
Annealing Behavior ◽  
Trapping Model ◽  
Mg Content ◽  
Migration Enthalpy

The migration enthalpy [Formula: see text] for point defects and dislocations is estimated by using positron lifetime technique; point defects and dislocations are produced as a result of plastic deformation at room temperature (RT) for the decomposition sequence, namely 5005, 5052 and 5083, of commercial Al – Mg systems. The results show that [Formula: see text] for the three systems increases as the Mg content is increased to u1=0.34±0.09 eV, u2=0.39±0.12 eV, and u3=0.42±0.08 eV for the point defect state, and u1=1.12±0.08 eV and u2=1.37±0.13 eV for the dislocation state to 5005 and 5052, respectively. All the data are analyzed in terms of the two state trapping model.

Slow Positron Studies of Defects in Si-Doped GaAs

2006 ◽  
Vol 251-252 ◽  
pp. 51-58
Author(s):  
B. Godbole ◽  
N. Badera ◽  
S.B. Shrivastava ◽  
K.P. Joshi
Keyword(s):  
Point Defects ◽  
Shape Parameter ◽  
Positron Lifetime ◽  
Doppler Broadening ◽  
Slow Positron ◽  
Si Doping ◽  
S Parameter ◽  
Trapping Model ◽  
Si Doped ◽  
Line Shape Parameter

The mechanism of slow positron annihilation in Si-doped GaAs has been discussed in terms of the diffusion trapping model (DTM). The trapping of positrons has been considered in SiAs acceptors i.e. shallow defects and in VGa-SiGa vacancy complexes. The model has been used to obtain the Doppler broadening line shape parameter (S-parameter) and average positron lifetime in Si-doped GaAs, for a temperature range 20K to 290K and for different doping concentrations. Observations are made regarding the effect of doping on the nature and concentration of point defects. The change in point defect concentration due to Si- doping has been found to be proportional to the doping concentration. The effect of detrapping from the shallow defects has been found to be important at higher temperatures.

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