Silica glass crucible and method for pulling up silicon single crystal using the same
View Patent ↗A silica glass crucible causing fewer pinholes in silicon single crystals is provided by a method of preventing pinholes by performing the pulling up of a silicon single crystal while restraining the dissolution rate of the crucible inner surface to 20 μm/hr or less, using a silica glass crucible for the pulling up of silicon single crystals, wherein the area of crystalline silica formed by crystallization of amorphous silica is restricted to 10% or less of the crucible inner surface area, or the density of pits formed from open bubbles on the crucible inner surface is restricted to 0.01 to 0.2 counts/mm 2 .
1. A method for pulling up a silicon single crystal from a silica glass crucible, the method comprising performing the pulling up of a silicon single crystal while restricting the dissolution rate of the crucible inner surface to 20 μm/hr or less, wherein the silica glass crucible has properties such that:
the area of crystalline silica formed by crystallization of amorphous silica to 10% or less of the inner surface area of the crucible; and
the density of pits originating from open bubbles on the crucible inner surface, to 0.01 to 0.2 counts/mm 2 .
2. The method for pulling up a silicon single crystal according to claim 1 , wherein the argon partial pressure inside the furnace during the pulling up of silicon is 0.40 to 66.7 kPa.
3. The method for pulling up a silicon single crystal according to claim 1 , wherein the temperature during the pulling up of the silicon single crystal is 1420 to 1550° C.
4. The method for pulling up a silicon single crystal according to claim 1 , wherein the temperature at the time of melting the silicon raw material is 1420 to 1600° C.
5. The method for pulling up a silicon single crystal according to claim 1 , wherein the size of the pit is 0.2 to 2.0 mm.
6. The method for pulling up a silicon single crystal according to claim 1 , wherein the pits are present on one side of the crucible surface.