
134 Crystal Growth and Evaluation of Silicon for VLSI and ULSI
to commercial FZ production of large silicon crystals with the needle-eye technique). The
ow is unstable for these conditions, and the velocity and temperature elds have oscilla-
tions in the melt. It is possible to obtain a stable ow for typical parameters if the growing
crystal is rotated faster. The convection in the molten zone inuences the heat transfer
through the growth front and the shape of this interface. The averaged-in-time unsteady
heat ux through the growth front differs from that in the case of steady-state ow without
Calculation
Experiment
a
c
b
FIGURE 4.40
Compar