Thermal waves of a nonaxisymmetric flow in a Czochralski-type silicon melt

Abstract

Thermal waves due to a nonaxisymmetric flow were observed at a Czochralski-type silicon-melt surface with a carbon-dummy crystal. The wave number and pattern transition of the thermal waves were investigated at various crucible rotation rates. The thermal wave number increased as the crucible rotation rate increased and the rotation rate of the thermal wave was lower than the crucible rotation rate. The nonaxisymmetric flow region for the 5″ CZ silicon melt was located at the thermal Rossby numbers of 1–10 2 and was higher than the region obtained for rotating annulus experiments.