High quality monocrystalline silicon now is the main semiconductor for
producing integrated circuits.
In recent years, crystal homogeneity and microstructure properties have become
very important with respect to the improvement of technological process.
Transition of the chip integration level to less then
0.13
scale makes
crystal lattice defects critical for chip yield.
Numerical model of crystal growth by the Czochralski technique
has been developed[1].
For crystals grown by the CZ method, the primary imperfections are point
defects (voids and oxygen precipitates),
which form during crystal growth and further thermal treatment.
Crystal growth is very complex process and fine
prediction of thermal field and impurity concentration is needed for
investigating defect interaction in the crystal during growth.
The model of initial defect (vacancy, self-interstitial and impurity atoms)
incorporation over the melt/crystal interface has been developed,
providing spatial distribution of initial defect concentrations.
Initial defect supersaturation during crystal cooling leads to formation
of void and oxygen precipitate nucleus in the vacancy-reach
zone of the crystal and growth of existing clusters[2,3].
We present the physical and numerical model of point defect clusterization
and growth kinetics. This model based on homogeneous
nucleation theory and diffusion limited growth described by the
Fokker-Planck equation.
Point defect concentration and size distribution function for different
crystal growth conditions have been obtained.
These models can be used for the prediction of point defect properties
and optimization of growth process for producing crystals with specified
quality.