The behavior of molten Silicon Surfaces was observed by using, non-invasive techniques such as laser microscopy. phase-shift Michelson interferometry and CCD thermometry. The Formation and oscillation of a non-axisymmetric temperature field clue to surface-tension-driven flow instability was revealed in a molten silicon bridge, which simulates floating zone configuration. For a flat surface. which represents a Czochralski melt. a hydrothermal wave was plausibly observed when the melt was shallow, whereas a cell pattern was observed during, crystal growth when the melt was deep. The cell pattern was modified by application of a magnetic field. (C) 2002 Elsevier Science B.V. All rights reserved.