Structure of Thermally-Induced Microdefects in Czochralski Silicon

1983 ◽  
Vol 31 ◽  
Author(s):  
F. A. Ponce ◽  
S. Hahn
Keyword(s):  
Quasi Equilibrium ◽  
Interstitial Oxygen ◽  
Thermally Induced ◽  
Czochralski Silicon ◽  
Oxygen Precipitation ◽  
Transmission Electron ◽  
Long Time ◽  
History Of ◽  
Silicon Materials ◽  
Oxygen Precipitates

ABSTRACTThe process of oxygen precipitation in Czochralski silicon materials has been studied using high resolution transmission electron microscopy. The resulting structure depends strongly on the thermal history of the material. The initial stages of precipitation involve the formation of clusters exhibiting strain fields which are coherent and isotropic at intermediate temperatures (∼7000°C). Incoherent defects are formed when the interstitial oxygen precipitates into substitutional sites in the silicon lattice. For long-time anneals, the quasi-equilibrium defect structure ranges from needle-like coesite (450–600°C), silica platelets (600–1000°C) to polyhedral silica precipitates (900–1200°C).

Oxygen Precipitation in Conventional and Nitrogen Co-Doped Heavily Arsenic-Doped Czochralski Silicon Crystals: Oswald Ripening

2009 ◽  
Vol 156-158 ◽  
pp. 275-278
Author(s):  
Xiang Yang Ma ◽  
Yan Feng ◽  
Yu Heng Zeng ◽  
De Ren Yang
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Czochralski Silicon ◽  
Silicon Crystals ◽  
Oxygen Precipitation ◽  
High Temperature Anneal ◽  
Oxygen Precipitates ◽  
Co Doped ◽  
Oswald Ripening

Oxygen precipitation (OP) behaviors in conventional and nitrogen co-doped heavily arsenic-doped Czocharalski silicon crystals subjected to low-high two-step anneals of 650 oC/8 h + 1000 oC/4-256 h have been comparatively investigated. Due to the nitrogen enhanced nucleation of OP during the low temperature anneal, much higher density of oxygen precipitates generated in the nitrogen co-doped specimens. With the extension of high temperature anneal, Oswald ripening of OP in the nitrogen co-doped specimens preceded that in the conventional ones. Moreover, due to the Oswald ripening effect, the oxygen precipitates in the conventional specimens became larger with a wider range of sizes. While, the sizes of oxygen precipitates in the nitrogen co-doped specimens distributed in a much narrower range with respect to the conventional ones.

Kinetic Model of Thermal Donor Evolution

1997 ◽  
Vol 469 ◽  
Author(s):  
K. F. Kelton ◽  
R. Falster
Keyword(s):  
Interstitial Oxygen ◽  
Oxygen Loss ◽  
Free Oxygen ◽  
Czochralski Silicon ◽  
Thermal Donor ◽  
Cluster Evolution ◽  
Oxygen Precipitation ◽  
High Diffusion Rate ◽  
Normal Diffusion ◽  
Small Clusters

ABSTRACTKinetic aspects of thermal donor (TD) formation in Czochralski silicon are shown to be consistent with the evolution of small oxygen clusters, as described within the classical theory of nucleation. Predictions for TD generation and interstitial oxygen loss are presented. Favorable agreement with experimental data requires that the rate constants describing cluster evolution be increased over those expected for a oliffusion-limited flux based on a normal diffusion coefficient for oxygen in silicon. This may signal an anomalously high diffusion rate for temperatures less than 500°C, as has been suggested by others. However, it may instead signal an enhanced concentration of free oxygen near clusters smaller than the critical size for nucleation. This is expected when the interfacial attachment rates become comparable with the rates at which oxygen atoms arrive in the vicinity of the sub-critical clusters. The link between thermal donor generation and oxygen precipitation processes demonstrated here provides a consistent framework for better understanding and controlling oxygen precipitation in silicon. Further, the kinetic TD generation and oxygen loss data provide a new window into the dynamical processes for small clusters, which underlie all nucleation phenomena.

First Principles Calculation for Point Defect Behavior, Oxygen Precipitation and Cu Gettering in Czochralski Silicon

2005 ◽  
Vol 108-109 ◽  
pp. 365-372 ◽  
Author(s):  
Koji Sueoka ◽  
S. Shiba ◽  
S. Fukutani
Keyword(s):  
Crystal Growth ◽  
Point Defect ◽  
First Principles ◽  
First Principles Calculation ◽  
Interstitial Oxygen ◽  
Defect Engineering ◽  
Czochralski Silicon ◽  
Oxygen Precipitation ◽  
Initial Stage ◽  
P Type

Theoretical consideration for technologically important phenomena in defect engineering of Czochralski silicon was performed with first principles calculation. (i) Point defect behaviour during crystal growth, (ii) enhanced oxygen precipitation in p/p+ epitaxial wafers, and (iii) Cu gettering by impurities are main topics in this work. Following results are obtained. (i) Interstitial Si I is dominant in p type Si while vacancy V is dominant in n type Si during crystal growth when dopant concentration is higher than about 1x1019atoms/cm3. (ii) In initial stage of oxygen precipitation including a few interstitial oxygen (O) atoms, BOn complex is more stable than On complex. The diffusion barrier of O atom in p+ Si is reduced to about 2.2eV compared with the barrier of about 2.5eV in intrinsic Si. (iii) In substitutional B, Sb, As, P and C atoms, only B atom can be an effective gettering center for Cu.

Temperature Ramping for Nucleation of Oxygen Precipitates in Silicon

1984 ◽  
Vol 36 ◽  
Author(s):  
R. F. Pinizzotto ◽  
H. F. Schaake ◽  
R. G. Massey ◽  
D. W. Heidt
Keyword(s):  
Volume Fraction ◽  
New Method ◽  
Number Density ◽  
Small Particles ◽  
Ramp Rate ◽  
Czochralski Silicon ◽  
Oxygen Precipitation ◽  
Temperature Ramp ◽  
Oxygen Precipitates ◽  
Precipitate Nucleation

ABSTRACTA new method for the nucleation of oxygen precipitates in Czochralski silicon is described. The temperature is ramped at approximately 100°C/hr from a very low value, near 400°C, to the highest temperature used for subsequent process steps. The technique generates a larger precipitate number density and a greater volume fraction of precipitated oxygen than standard isothermal nucleation anneals. The morphology of the precipitates changes from 0.lum sizéd (100) platelets to small particles unresovable by TEM. The new temperature ramping technique can reduce the time needed for precipitate nucleation by at least a factor of three. The details of oxygen precipitation can be totally controlled by adjusting the temperature ramp rate as a function of time.

Crystallographic Analysis Of Flow Pattern Defects In Dislocated Czochralski Silicon Crystals

1996 ◽  
Vol 442 ◽  
Author(s):  
Y. Ikematsu ◽  
T. Iwasaki ◽  
H. Harada ◽  
K. Tanaka ◽  
M. Fujinami ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Crystallographic Analysis ◽  
Crystal Defects ◽  
Dislocation Loops ◽  
Etch Pits ◽  
Czochralski Silicon ◽  
Silicon Crystals ◽  
Transmission Electron ◽  
Type Dislocation ◽  
Oxygen Precipitates

AbstractIn dislocated Cz-Si crystals, rows of flow patterns (FP) and Secco etch pits (SEP) (2–3 mm in length, along <110> direction) can be revealed by Secco etch without agitation. In this study, the crystal defects forming FP-SEP rows in dislocated Cz-Si crystals are investigated by transmission electron microscopy. Microdefects, 0.1 μm in size, are observed in a row along a FP-SEP row, <110> direction. These defects were identified as oxygen precipitates with or without dislocation loops (interstitial-type), and voids with oxidized interiors. We conclude that FP originate from interstitial-type dislocation loops, and SEP are due to oxygen precipitates or voids.

Oxygen Precipitation in Silicon: Numerical Models

1985 ◽  
Vol 59 ◽  
Author(s):  
J. P. Lavine ◽  
G. A. Hawkins ◽  
C. N. Anagnostopoulos ◽  
L. Rivaud
Keyword(s):  
Experimental Data ◽  
Numerical Model ◽  
Numerical Models ◽  
Local Concentration ◽  
Interstitial Oxygen ◽  
Czochralski Silicon ◽  
Oxygen Precipitation ◽  
Precipitate Growth ◽  
Evolution Of Precipitates ◽  
Precipitate Density

ABSTRACTWe present a numerical model that simulates the evolution of precipitates and the diffusion of interstitial oxygen in Czochralski silicon. The growth and/or dissolution of each precipitate and the local concentration of interstitial oxygen with which the precipitates interact are followed as a function of time. We treat realistic densities of discrete, interacting precipitates and determine how the precipitate density influences the extent of the precipitation. The model also treats oxygen outdiffusion and the formation of precipitate-free or denuded zones. We apply the model to previous experimental data on the time dependence of precipitate growth and to the development of denuded zones during intrinsic gettering.

Transmission Electron Microscope Studies of O, C, N Precipitation in Crystalline Silicon

1985 ◽  
Vol 59 ◽  
Author(s):  
A. Bourret
Keyword(s):  
Crystalline Silicon ◽  
Annealing Treatment ◽  
High Resolution Electron Microscopy ◽  
Czochralski Silicon ◽  
Oxygen Precipitation ◽  
Transmission Electron ◽  
Resolution Electron ◽  
One Step ◽  
Precipitation Phenomena

ABSTRACTThe understanding of the precipitation phenomena of light non dopant Impurities has been recently improved thanks to high resolution electron microscopy and microanalysis. After a one-step annealing in Czochralski silicon long coesite (SIO2) ribbons are formed between 485° and 750°C; amorphous platelets (SIOx with x =1. 2 to 2) are formed between 650°C -1050°C. Silicon Interstitlals generated during the precipitation partly relax the strain energy associated with the volume change. These Interstltlals are also able to precipitate In various forms. After a two-step annealing both platelets and/or octahedra containing amorphous SIOx are formed. The role of carbon on oxygen precipitation Is important: It changes the nucleation parameters and gives a retardation phenomena In a two-step annealing treatment. Similar phenomena are observed in oxygen implanted silicon. The nucleation and growth process able to explain these observations is far from being well understood. The SIO2 polymorphism, the Important role of SI Interstitials and the mutual attraction between oxygen and carbon are some of the ingredients which explain this complexity.

Nucleation of Oxygen Precipitates in a Quenched Czochralski Silicon Crystal

1992 ◽  
Vol 262 ◽  
Author(s):  
A. Ikari ◽  
H. Haga ◽  
O. Yoda ◽  
A. Uedono ◽  
Y. Ujihira
Keyword(s):  
Annealing Temperature ◽  
Silicon Crystal ◽  
Ir Absorption ◽  
Quenching Temperature ◽  
Annealing Behavior ◽  
Czochralski Silicon ◽  
Oxygen Precipitation ◽  
Ir Absorption Spectra ◽  
Oxygen Precipitates ◽  
Oxygen Complexes

ABSTRACTWe have studied the nucleation of oxygen precipitates in Czochralski (Cz) Si crystal quenched from high temperature (1390°C). We observed that the oxygen precipitation was enhanced by the quenching treatment. We found the density of precipitates in the quenched crystal depended on quenching temperature and that nuclei for oxygen precipitates were introduced during quenching. We studied these nuclei using infrared absorption (IR) and positron annihilation techniques. In order to clarify the state of the nuclei, the quenched specimens were irradiated with 3-MeV electrons at a dose of 1×1018e/cm2 and vacancy-oxygen complexes were introduced. Positron lifetime spectra and IR absorption spectra for these specimens were measured as a function of isochronal annealing temperature. From the annealing behavior of the vacancy-oxygen complexes, it was found that oxygen clusters are introduced by the quenching and these clusters are the nuclei for the enhanced precipitation of the quenched Si crystal.

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