QUARTZ GLASS CRUCIBLE OBTAINED BY ELECTROLYTIC REFINING AND HAVING HIGH PURITY AT ITS INNER CIRCUMFERENCE, MANUFACTURING METHOD THEREOF AND PULLING METHOD THEREOF

摘要

PURPOSE: Provided is a quartz glass crucible having high purity at the part of its inner circumference, suitable to be used in a method for pulling monocrystalline silicon for semiconductors from molten silicon. CONSTITUTION: The quartz glass crucible is manufactured by heating powder of quartz raw material present in the inside of a hollow rotational mold(10) with electric arc, wherein an electric voltage is applied between the mold(10) and an arc electrode(13) to cause metal impurities contained in the molten quartz glass disposed at the inner circumference of the crucible to be moved toward the outer circumference so that the purity of the molten quartz glass is increased. The arc-melting of the quartz material is performed until the thickness of the resultant glass layer becomes a thickness of 5 mm or more and that of the non-molten quartz glass layer becomes 2 mm or less. During the arc-melting, an earth arc electrode is maintained at a potential of +/- 500V. A voltage of -1,000 to -20,000 V is applied to the mold electrically insulated with the earth.