Patent ID: 9738988
Date: 2017-08-22
CPC Classifications: C30B

Claim:
1. A method for manufacturing a plurality of pieces of single crystal based on a Czochralski method, comprising: analyzing Ni concentration in graphite components used in a furnace in which the single crystal is manufactured; and manufacturing the plurality of pieces of single crystal by multi-pulling using the graphite components when the analyzed Ni concentration is 30 ppb or less, wherein a quantitative lower limit for measurement of an impurity is 5 to 10 ppb in the step of analyzing Ni concentration; the graphite components having a Ni concentration of 30 ppb or less include both a graphite component that is directly in contact with a quartz crucible and a graphite component that is indirectly in contact with the quartz crucible through the graphite component that is directly in contact; the graphite component that is directly in contact with the quartz crucible includes a graphite crucible; and the graphite component that is indirectly in contact with the quartz crucible through the graphite component that is directly in contact includes both a crucible receiver and a pedestal.