Quartz glass crucible for pulling silicon single crystal and production process for such crucible

A production process for a quartz glass crucible for pulling a silicon single crystal in which a rotary upward-open mold is used, comprising the steps of:

• (a) forming a preform in conformity of an inner surface of the mold by supplying silica powder into the mold;
• (b) forming a crucible base body made of a translucent quartz glass by heat melting the preform;
• and
• (c) forming a synthetic quartz glass layer by supplying synthetic silica powder into a high temperature gas atmosphere inside the crucible base body and dispersing the powder in a molten state to an inner wall surface of the crucible base body while or after the crucible base body is formed, wherein
• when the quartz glass crucible thus produced is used and a silicon single crystal is pulled with the quartz glass crucible, a portion encircled by a brown ring on an inner surface of the quartz glass crucible is uniformly crystallized.

A production process for a quartz glass crucible for pulling a silicon single crystal in which a rotary upward-open mold is used, comprising the steps of:

• (a) forming a preform in conformity of an inner surface of the mold by supplying silica powder into the mold;
• (b) forming a crucible base body made of a translucent quartz glass by heat melting the preform;
• and
• (c) forming a synthetic quartz glass layer by supplying synthetic silica powder into a high temperature gas atmosphere inside the crucible base body and dispersing the powder in a molten state to an inner wall surface of the crucible base body while or after the crucible base body is formed, wherein
• a hydroxyl group content and a nitrogen content in the synthetic quartz glass layer are respectively adjusted in predetermined ranges and thereby a viscosity of the synthetic quartz glass layer is set in a predetermined range.