Cluster Computations Related to Silicon Thermal Donors

1985 ◽  
Vol 59 ◽  
Author(s):  
Lawrence C. Snyder ◽  
James W. Corbett
Keyword(s):  
Crystalline Silicon ◽  
Silicon Crystal ◽  
Silicon Monoxide ◽  
Interstitial Oxygen ◽  
Hydrogen Atoms ◽  
Oxygen Complex ◽  
Quantum Chemical Computations ◽  
Silicon Oxygen ◽  
Boron Carbon ◽  
Oxygen Atoms

ABSTRACTAb-initio quantum chemical computations have been applied to a set of molecular clusters derived from Si5 H12 to model defects in crystalline silicon involving boron, carbon, nitrogen, oxygen, and hydrogen. In computations of defect structure, hydrogen atoms terminating silicon valencies are fixed at their computed positions in Si5H12, to represent forces from the lattice, while the position of other atoms are varied.We have computed the stable bonding structures of boron, carbon, nitrogen and oxygen atoms to a vacancy, as well as interstitial oxygen, the silicon-oxygen ylid and two oxygen atoms bound to a vacancy. The structures of the dipositive ions of the oxygen bearing clusters have been computed as part of a search for candidates for the core of the 450° C oxygen thermal donor in silicon crystal. The computed cluster energies are employed to give an account of defect thermochemistry; the addition of the free atoms to a vacancy, the addition of interstitial oxygen atoms to a vacancy, the reaction of interstitial oxygen atoms to form a vacancy-oxygen complex with the emission of silicon monoxide, and the reaction of interstitial oxygen with the dipositive ion of substitutional oxygen to form the dipositive ion of two oxygen atoms bound to a vacancy.

Germanium Doping and Impurities Analysis on Industrial Scale Mc-Silicon Ingot

2012 ◽  
Vol 164 ◽  
pp. 207-213
Author(s):  
Shuai Li ◽  
Peng Wu ◽  
Bai Tong Zhao ◽  
Wen Xiu Gao
Keyword(s):  
Crystalline Silicon ◽  
Silicon Crystal ◽  
Industrial Scale ◽  
Scale Production ◽  
Interstitial Oxygen ◽  
Minority Charge Carrier ◽  
Pressing Method ◽  
Silicon Ingot ◽  
Dislocations Density ◽  
The Impact

With mc-silicon (multi-crystalline silicon) being the most favorable feedstock for solar cell, germanium was reported to be a promising dopant to improve the quality of silicon crystal growth. In this paper, we investigated the feasibility of germanium doping for industrial scale production. A homogeneously distribution of germanium across usable section is presented, and subsequently we optimized our recipe for better controlling it. Sopori etched pits were utilized to reveal dislocations in silicon wafers, and we found a reduced dislocations density in germanium doped samples. Carbon and oxygen are two inevitable significant impurities during silicon ingot casting. In this paper, experimental results showed the impact of carbon on minority charge carrier lifetime and on interstitial oxygen. In addition, Isostatic pressing method is proved to be very prospective for recycling quartz crucibles.

Monoenergetic Positron Beam Studies of Oxygen in Single Crystal Silicon - Stress Induced Clustering of Oxygen Atoms in Silicon

1992 ◽  
Vol 262 ◽  
Author(s):  
R. Nagai ◽  
E. Takeda ◽  
Y. Tabuki ◽  
L. Wei ◽  
S. Tanigawa
Keyword(s):  
Silicon Oxide ◽  
Intrinsic Value ◽  
Silicon Crystal ◽  
Single Crystal Silicon ◽  
Positron Beam ◽  
Interstitial Oxygen ◽  
Bulk Silicon ◽  
Crystal Silicon ◽  
S Parameter ◽  
Oxygen Atoms

ABSTRACTA monoenergetic positron beam has been used to investigate the state of interstitial oxygen in Czochralski (CZ)-grown Si with either thermally grown S1O2 (100 nm thick) or silicon oxide (p-SiOx) deposited by plasma enhanced chemical vaper deposition technique on the surface. Both the growth of thermal SiO2 and the deposition of SiOx film resulted in a reduction of the doppler-broadening line shape parameter (S-parameter) for the positron annihilation in the bulk silicon region. Annealing at 450δC, the removal of oxide overlayer or long-term aging at room temperature caused the S-parameter to return to its intrinsic value. It was thought that tensile stress in silicon, induced by the thermal oxidation or the deposition of SiOx films which had compressive internal stress themselves, enhanced the rearrangement of oxygen atoms and caused the formation of oxygen clusters in silicon crystal. Oxygen interstitial clusters can trap positrons leading to the lower S-parameter value for annihilation in the bulk silicon region, because of large overlap with core electrons. The above results suggest that oxygen atoms can absorb lattice strain by clustering and thus prevent the generation of dislocations against external stress in the Si lattice. This results yield an additional explanation of the high mechanical strength of CZ Si crystal.

Investigation of the Hydrogen Transport Processes in Crystalline Silicon of n-Type Conductivity

2007 ◽  
Vol 131-133 ◽  
pp. 425-430 ◽  
Author(s):  
Anis M. Saad ◽  
Oleg Velichko ◽  
Yu P. Shaman ◽  
Adam Barcz ◽  
Andrzej Misiuk ◽  
...  
Keyword(s):  
Hydrogen Concentration ◽  
Room Temperature ◽  
Crystalline Silicon ◽  
Transport Processes ◽  
Concentration Profiles ◽  
Hydrogen Transport ◽  
Hydrogen Atoms ◽  
Near Surface ◽  
Type Conductivity ◽  
Hydrogen Molecules

The silicon substrates were hydrogenated at approximately room temperature and hydrogen concentration profiles vs. depth have been measured by SIMS. Czochralski grown (CZ) wafers, both n- and p-type conductivity, were used in the experiments under consideration. For analysis of hydrogen transport processes and quasichemical reactions the model of hydrogen atoms diffusion and quasichemical reactions is proposed and the set of equations is obtained. The developed model takes into account the formation of bound hydrogen in the near surface region, hydrogen transport as a result of diffusion of hydrogen molecules 2 H , diffusion of metastable complexes * 2 H and diffusion of nonequilibrium hydrogen atoms. Interaction of 2 H with oxygen atoms and formation of immobile complexes “oxygen atom - hydrogen molecule” (O - H2 ) is also taken into account to explain the hydrogen concentration profiles in the substrates of n-type conductivity. The computer simulation based on the proposed equations has shown a good agreement of the calculated hydrogen profiles with the experimental data and has allowed receiving a value of the hydrogen molecules diffusivity at room temperature.

Monte Carlo Simulation of Precipitate Nucleation and Growth: Time Dependent Results

1988 ◽  
Vol 141 ◽  
Author(s):  
James P. Lavine ◽  
Gilbert A. Hawkins
Keyword(s):  
Monte Carlo ◽  
Crystalline Silicon ◽  
Three Dimensional ◽  
Nucleation Site ◽  
Nucleation And Growth ◽  
Lattice Points ◽  
Growth Time ◽  
Decay Kinetics ◽  
Time Step ◽  
Oxygen Atoms

AbstractA three-dimensional Monte Carlo computer program has been developed to study the heterogeneous nucleation and growth of oxide precipitates during the thermal treatment of crystalline silicon. In the simulations, oxygen atoms move on a lattice with randomly selected lattice points serving as nucleation sites. The change in free energy that the oxygen cluster would experience in gaining or losing one oxygen atom is used to govern growth or dissolution of the cluster. All the oxygen atoms undergo a jump or a growth decision during each time step of the anneal. The growth and decay kinetics of each nucleation site display interesting fluctuation phenomena. The time dependence of the cluster size generally differs from the expected 3/2 power law due to the fluctuations in oxygen arrival at and incorporation in a precipitate. Competition between growing sites and coarsening are observed.

Carbacylamidophosphates: Synthethis and Structure of N,N'-Tetramethyl-NM-benzoylphosphoryltriamide and Dimorpholido-N-benzoylphosphorylamide

2000 ◽  
Vol 55 (6) ◽  
pp. 495-498 ◽  
Author(s):  
Katerina E. Gubina ◽  
Vladimir A. Ovchynnikov ◽  
Vladimir M. Amirkhanov ◽  
Viktor V. Skopenkoa ◽  
Oleg V. Shishkinb
Keyword(s):  
Nmr Spectroscopy ◽  
Hydrogen Bonds ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
Sodium Salts ◽  
Space Group ◽  
X Ray ◽  
Centrosymmetric Dimers ◽  
Oxygen Atoms

N,N′-Tetramethyl-N"-benzoylphosphoryltriamide (I) and dimorpholido-N-benzoylphosphorylamide (II), and their sodium salts Nal, Nall were synthesized and characterized by means of IR and 1H, 31P NMR spectroscopy. The structures of I, II were determined by X-ray diffraction: I monoclinic, space group P2i/c with a = 10.162(3), b= 11.469(4), c = 12.286(4) Å , β = 94.04°, V = 1428.4(8) A 3, Z = 4, p(calcd) = 1.187 g/cm3; II monoclinic, space group C2/c with a = 15.503(4), b = 10.991(3), c = 22.000(6) Å, β = 106.39°, V = 3596.3(17) Å3, Z = 8, p(calcd.) = 1.253 g/cm3. The refinement of the structures converged at R = 0.0425 for I, and R = 0.068 for II. In both structures the molecules are connected into centrosymmetric dimers via hydrogen bonds formed by the phosphorylic oxygen atoms and hydrogen atoms of amide groups.

A New Type of Ordered Arrangement of Interstitial Oxygen Atoms in the a Solid Solution of the Zr-O System

1972 ◽  
Vol 32 (4) ◽  
pp. 1146-1146 ◽  
Author(s):  
Shinya Hashimoto ◽  
Hiroshi Iwasaki ◽  
Shiro Ogawa ◽  
Sadae Yamaguchi ◽  
Makoto Hirabayashi
Keyword(s):  
Solid Solution ◽  
Interstitial Oxygen ◽  
New Type ◽  
Oxygen Atoms

Identification of An Interstitial Carbon – Interstitial oxygen Complex in Silicon

1987 ◽  
Vol 104 ◽  
Author(s):  
J. M. Trombetta ◽  
G. D. Watkins
Keyword(s):  
Carbon Atom ◽  
Oxygen Atom ◽  
Lattice Relaxation ◽  
Luminescence Spectra ◽  
Interstitial Oxygen ◽  
Epr Spectrum ◽  
Interstitial Carbon ◽  
Oxygen Complex ◽  
Interaction Tensor ◽  
Carbon Interstitial

ABSTRACTThe Si-G15 EPR spectrum and the 0.79eV “C-line” luminescence spectra in silicon are shown to arise from an interstitial carbon - interstitial oxygen complex. The g-tensor and 13C hyperfine interaction tensor indicate the structure in the vicinity of the carbon atom while stress alignment studies reveal the configuration near the oxygen atom. The pairing of the two impurities leads to a lattice relaxation which serves to stabilize the complex against dissociation.

X-Ray Measurement of the Static Lattice Distortion in the Solid Solution of Oxygen in Titanium*

1962 ◽  
Vol 6 ◽  
pp. 136-141
Author(s):  
F. R. L. Schoening ◽  
F. Witt
Keyword(s):  
Single Crystal ◽  
Oxygen Concentration ◽  
Waller Factor ◽  
Interstitial Oxygen ◽  
Exponential Factor ◽  
X Ray ◽  
X Ray Scattering ◽  
Lattice Strains ◽  
Debye Waller Factor ◽  
Oxygen Atoms

AbstractOxygen was introduced into a single crystal of titanium in successive stages. The intensities of the h00 and 00l reflections were measured with a single-crystal diffractometer. The observed variation of the intensities with oxygen concentration was attributed to three factors: (1) the additional scattering from the oxygen atoms, (2) a change in the Debye-Waller factor, and (3) an exponential factor originating from the distortion around the oxygen atom. The theory of X-ray scattering from crystals containing centers of distortion was applied to the hexagonal titanium containing interstitial oxygen atoms. Using the variation of the lattice constant with oxygen concentration, it was possible to predict the intensity reduction due to lattice strains. It was concluded that it would have been possible to obtain an estimate of the defect concentration from the X-ray measurements of lattice expansion and intensity reduction.

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