SILICA CRUCIBLE WITH PURE AND BUBBLE-FREE INNER CRUCIBLE LAYER AND METHOD FOR MAKING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a method for making a silica crucible, capable of making the silica crucible, having an inner crucible layer with minimal impurity concentration and reduced bubble and bubble-growth, at reasonable cost.SOLUTION: A method for fusing an inner silica layer and at least one additional silica layer containing higher concentration of metallic impurities than the inner silica layer includes: forming a first fused silica layer by fusing at least a portion of the inner silica layer at a first power; forming a second fused silica layer by fusing at least a portion of the at least one additional silica layer at a second power greater than the first power; and sublimating a portion of the first fused silica layer.