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

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 crucib le rotation rates. The thermal wave number increased as the crucible rotati on 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 s ilicon melt was located at the thermal Rossby numbers of 1-10(2) and was hi gher than the region obtained for rotating annulus experiments, (C) 1999 El sevier Science B.V. All rights reserved.