| 摘要 |
PROBLEM TO BE SOLVED: To provide a melt level detector capable of simply and precisely detecting a melt level and also to provide a melt level detection method using the detector. SOLUTION: The detection method using this detector for detecting the melt level of a melt surface in a CZ(Czochralski) furnace on the basis of the principle of triangulation, comprises: moving the projection position on the melt surface of a laser beam 2 from a laser beam irradiator, in the radial direction of a crucible 14 in the CZ furnace, to scan such a projection position that the laser beam 2 reflected from the melt surface is received by a laser beam receiver; and setting the projection position to this position. Thus, since an appropriate melt surface part for detecting a melt level 3 is found by scanning the projection angle within a very narrow range and measurement of the melt level 3 is performed in this appropriate part, complication of the detector can be avoided and detection of the melt level 3 is performed in such a state that the influence of noise caused in the melt surface, on the detection is reduced. |
