Instability of the Marangoni flow of molten silicon is discussed. Time-dependent behavior of azimuthal wave numbers (m) for flow instability was investigated based on temperature oscillation measurements using a theta-t analysis, and appearance ratio of each azimuthal wave number is analyzed. The relationship between frequency and azimuthal wave numbers is deduced from an analysis of appearance ratios at a decomposed frequency band using a wavelet analysis. Oxygen partial pressure at the melt surface can be predicted using the Ratto-Ricci-Arato model. Anomalous recalescence behavior and surface oxidation of levitated molten silicon are shown. Growth striation is induced in silicon crystals grown even under high oxygen-partial pressure. (C) 2005 Springer Science + Business Media, Inc.