Patent ID: 8871023

Claim:
A silicon single crystal pull-up apparatus comprising: a chamber into which an inert gas is introduced; a crucible that supports a silicon melt within the chamber; a heater that heats the silicon melt in the crucible; a lifting device for lifting and lowering the crucible; a thermal radiation shield disposed above the crucible; a purging tube that has substantially cylindrical shape and is provided inside the thermal radiation shield so as to straighten the inert gas; a camera that photographs a mirror image of the thermal radiation shield reflected on the liquid surface of the silicon melt through the purging tube; a liquid surface level calculator that calculates a liquid surface level of the silicon melt from the position of the mirror image photographed by the camera; and a conversion table creator that creates a conversion table representing a relationship between the liquid surface level of the silicon melt and the mirror image position obtained when the crucible is lifted and lowered before start of a single crystal pull-up process to arbitrarily change the liquid surface level of the silicon melt, wherein the liquid surface level calculator calculates the liquid surface level based on the position of the mirror image photographed by the camera and the conversion table.