| 摘要 |
<P>PROBLEM TO BE SOLVED: To correctly measure a liquid surface level even when a purge tube is installed at the inside of a thermal radiation shield. <P>SOLUTION: A silicon single crystal pull-up apparatus 10 is provided with: a crucible 12 that supports a silicon melt within a chamber 11; a heater that heats the silicon melt in the crucible 12; a thermal radiation shield 16 disposed above the crucible; an almost cylindrical purging tube 17 that is provided inside the thermal radiation shield 16 so as to straighten the inert gas; a CCD camera 18 that photographs the mirror image of the thermal radiation shield 16 reflected on the liquid surface of the silicon melt 1 through the purging tube; a liquid surface level calculator 31 that calculates the liquid surface level of the silicon melt from the position of the mirror image of the thermal radiation shield 16; and a conversion table creator 32 that creates a conversion table representing a relationship between the liquid surface level of the silicon melt and the mirror image position obtained. The liquid surface level calculator 31 calculates the liquid surface level on the basis of the conversion table. <P>COPYRIGHT: (C)2012,JPO&INPIT |
