Patent ID: 9650724
Date: 2017-05-16
CPC Classifications: C30B,Y10T

Claim:
1. A method of charging raw material to a quartz crucible in a single-crystal manufacturing process including charging the raw material to the quartz crucible, melting the raw material into melt in the quartz crucible, and pulling a single crystal from the melt, comprising: storing the raw material in a recharge tube including a quartz cylinder configured to store the raw material and a conical valve configured to open or close an opening positioned at a lower end of the cylinder; installing the recharge tube storing the raw material in a chamber; and feeding the raw material stored in the recharge tube into the quartz crucible by locating the recharge tube and the quartz crucible such that a distance between the lower end of the recharge tube and raw material or melt in the quartz crucible ranges from 200 mm to 250 mm at the start of a raw-material feeding operation, and then lowering the conical valve to open the opening positioned at the lower end of the cylinder while simultaneously lowering the quartz crucible such that a ratio CL/SL ranges from 1.3 to 1.45, where CL is a lowering speed of the quartz crucible and SL is a lowering speed of the conical valve of the recharge tube.