METHOD FOR DETECTING TEMPERATURE OF MELT IN CZOCHRALSKI METHOD

摘要

PURPOSE:To continuously and accurately detect the temp. of a melt and to improve the accuracy of single crystal pulling up work by indirectly measuring the temp. of the melt from the amplitude and period of fluctuation on the surface of the melt. CONSTITUTION:The surface of a melt 2 is irradiated with light 9 such as laser light and the light 9 is reflected. This reflected light 7 oscillates in accordance with fluctuation on the surface of the melt 2. The fluctuation amplitude and oscillation period of the optical axis of the reflected light 7 are measured, the intensity of the fluctuation is calculated from the measured values and the temp. of the melt 2 is calculated from the calculated intensity.