Quartz glass crucible, manufacturing method of silicon single crystal using the same, and infrared transmissivity measurement method and manufacturing method of quartz glass crucible

A quartz glass crucible comprising:

• a cylindrical side wall portion;
• a bottom portion;
• a corner portion connecting the side wall portion and the bottom portion to each other;
• a transparent layer made of quartz glass that does not contain bubbles;
• a bubble layer formed outside the transparent layer and made of quartz glass containing a large number of bubbles;
• a semi-molten layer formed outside the bubble layer and made of raw material silica powder solidified in a semi-molten state;
• and
• at least one semi-molten layer-removed portion formed of a region from which a portion of the semi-molten layer has been removed.

An infrared transmissivity measurement method of a quartz glass crucible,

• in which the quartz glass crucible includes
• a transparent layer made of quartz glass that does not contain bubbles,
• a bubble layer formed outside the transparent layer and made of quartz glass containing a large number of bubbles, and
• a semi-molten layer formed outside the bubble layer and made of raw material silica powder solidified in a semi-molten state,
• the infrared transmissivity measurement method comprising:
• a step of processing an outer surface of the quartz glass crucible formed by the semi-molten layer so that a surface roughness of the outer surface becomes low;
• and
• a step of measuring an infrared transmissivity of the quartz glass crucible based on infrared light passing through the outer surface after processing the outer surface.

A manufacturing method of a quartz glass crucible,

• in which the quartz glass crucible includes
• a transparent layer made of quartz glass that does not contain bubbles,
• a bubble layer formed outside the transparent layer and made of quartz glass containing a large number of bubbles, and
• a semi-molten layer formed outside the bubble layer and made of raw material silica powder solidified in a semi-molten state,
• the manufacturing method comprising:
• a step of manufacturing a first quartz glass crucible based on first manufacturing conditions;
• a step of processing an outer surface of the first quartz glass crucible formed by the semi-molten layer so that a surface roughness of the outer surface becomes low;
• a step of measuring an infrared transmissivity of the first quartz glass crucible based on infrared light passing through the outer surface after processing the outer surface;
• and
• a step of manufacturing a second quartz glass crucible based on second manufacturing conditions modified based on a measurement result of the infrared transmissivity of the first quartz glass crucible so that a measured value of the infrared transmissivity becomes a target value.