Numerical modelling of Czochralski growth of quadratic silicon crystals by means of a travelling magnetic field

2011 ◽  
Vol 47 (3) ◽  
pp. 285-292 ◽  
Author(s):  
W. Miller ◽  
Ch. Frank-Rotsch ◽  
M. Czupalla ◽  
P. Rudolph
Keyword(s):  
Magnetic Field ◽  
Numerical Modelling ◽  
Czochralski Growth ◽  
Silicon Crystals

Numerical Study of the Effect of Magnetic Fields on Melt-Crystal Interface-Deflection in Czochralski Crystal Growth

2003 ◽  
Author(s):  
Lijun Liu ◽  
Koichi Kakimoto
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Numerical Study ◽  
Silicon Crystal ◽  
Czochralski Growth ◽  
Thermal Flow ◽  
Interface Shape ◽  
Convective Thermal ◽  
And Control ◽  
Crystal Interface

In order to control the impurity distribution and remove defects in a crystal grown in Czochralski growth for high quality crystals of silicon, it is necessary to study and control the melt-crystal interface shape, which plays an important role in control of the crystal quality. The melt-crystal interface interacts with and is determined by the convective thermal flow of the melt in the crucible. Application of magnetic field in the Czochralski system is an effective tool to control the convective thermal flow in the crucible. Therefore, the shape of the melt-crystal interface can be modified accordingly. Numerical study is performed in this paper to understand the effect of magnetic field on the interface deflection in Czochralski system. Comparisons have been carried out by computations for four arrangements of the magnetic field: without magnetic field, a vertical magnetic field and two types of cusp-shaped magnetic field. The velocity, pressure, thermal and electromagnetic fields are solved with adaptation of the mesh to the iteratively modified interface shape. The multi-block technique is applied to discretize the melt field in the crucible and the solid field of silicon crystal. The unknown shape of the melt-crystal interface is achieved by an iterative procedure. The computation results show that the magnetic fields have obvious effects on both the pattern and strength of the convective flow and the interface shape. Applying magnetic field in the Czochralski system, therefore, is an effective tool to control the quality of bulk crystal in Czochralski growth process.

Reactions between liquid silicon and vitreous silica

1992 ◽  
Vol 7 (2) ◽  
pp. 352-358 ◽  
Author(s):  
Zhensheng Liu ◽  
Torbjörn Carlberg
Keyword(s):  
Thin Layer ◽  
Vitreous Silica ◽  
Liquid Silicon ◽  
Oxygen Flux ◽  
Molten Silicon ◽  
Lateral Growth ◽  
Czochralski Growth ◽  
Oxygen Incorporation ◽  
Silicon Crystals ◽  
Oxygen Concentrations

Oxygen incorporation in silicon crystals during Czochralski growth is dependent on many factors, of which the dissolution of the silica crucible is of great importance. In this paper the reactions between vitreous silica and molten silicon have been analyzed, both in sealed ampoules and in Czochralski crucibles. It was found that the vitreous silica crystallizes to cristobalite by lateral growth. For this reaction to occur it is necessary that liquid silicon is present. The vitreous silica dissolves and the cristobalite grows with a thin layer of liquid silicon between them. Different oxygen concentrations in the melt in equilibrium with the amorphous and crystallized silica are necessary for the reaction to proceed. The oxygen flux in the melt is dependent upon the dissolution of both vitreous silica and cristobalite as well as the reaction between these phases.

scholarly journals Winds from Disks

1990 ◽  
Vol 122 ◽  
pp. 228-235
Author(s):  
J.E. Drew
Keyword(s):  
Magnetic Field ◽  
Numerical Modelling ◽  
Mass Loss ◽  
Weak Magnetic Field ◽  
Cataclysmic Variables ◽  
Dwarf Novae ◽  
Loss Mechanism ◽  
Fundamental Cause ◽  
Magnetic Cataclysmic Variables ◽  
Thermonuclear Runaway

The disks referred to in the title of this paper are specifically those present in cataclysmic variables in which the accreting white dwarf has a relatively weak magnetic field (≪ 1 MG). Such systems are classified either as nova-like variables or as dwarf novae, and are of interest here because they are believed to be novae in quiescence (Ritter and Livio discuss this point elsewhere in this volume).This review aims to do two things: i) to summarise what has been learned about the winds associated with non-magnetic cataclysmic variables both from observation and from numerical modelling, and ii) to outline ideas about the nature of the mass loss mechanism. By contrast with the certainty that nova outflows are the consequence of thermonuclear runaway, it shall be seen that the fundamental cause of mass loss from cataclysmic variables remains obscure. An earlier review of this subject is by Cordova and Howarth (1986). Also of interest are some sections of the monograph on dwarf novae and nova-like variables by LaDous (1989).

The use of heater-magnet module for Czochralski growth of PV silicon crystals with quadratic cross section

2011 ◽  
Vol 318 (1) ◽  
pp. 249-254 ◽  
Author(s):  
P. Rudolph ◽  
M. Czupalla ◽  
B. Lux ◽  
F. Kirscht ◽  
Ch. Frank-Rotsch ◽  
...  
Keyword(s):  
Cross Section ◽  
Czochralski Growth ◽  
Silicon Crystals
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