| 摘要 |
PROBLEM TO BE SOLVED: To prevent attachment of impurity to polycrystalline silicon and improve free ratio of the pulled single crystalline silicon. SOLUTION: The lid 10 for the crucible is composed of the lid body 13 with the vent-hole 13c in the middle covering the upper opening mouth of the quartz pot 12 and the filter 14 attached to the upper part of the lid body 13 covering the vent-hole 13c. The melting method includes such processes as the process that the quartz crucible 12 is installed in the chamber after the polycrystalline silicon 11 being put in the crucible and the upper opening mouth of the crucible covered with the lid, the process that the inactive gas is input after the chamber being vacuumed inside, the process that the lid is taken away from the quartz after the chamber being in the atmospheric pressure, the process that the inactive gas is input again after the chamber being vacuumed, and the process that the polycrystalline silicon 11 is melted with a carbon heater in the inactive gas filled atmosphere during or after the inactive gas input.
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