Vitreous silica crucible

Patent metadata

Field	Value
Publication number	US-9115445-B2
Application number	US-201013148457-A
Country	US
Kind code	B2
Filing date	Dec 13, 2010
Priority date	Dec 11, 2009
Publication date	Aug 25, 2015
Grant date	Aug 25, 2015

Abstract

Provided is a vitreous silica crucible which has a special region for suppressing vibration of melt surface during pulling of a silicon single crystal and at the same time, a marking capable of accurately monitoring a changed position of the melt surface when passing through the special region. The special region for preventing sloshing of silicon melt is provided on an inner wall of a straight body portion, and the marking is provided at least at an upper end and a lower end of the special region.

First claim

The invention claimed is:

1. A vitreous silica crucible containing silicon melt, the vitreous silica crucible comprising:
a special region for suppressing sloshing of melt surface of the silicon melt, provided on an inner wall of a straight body portion; and
a marking, which is not a part of the special region, installed at least an upper end and a lower end of the special region, wherein the marking installed at the upper end of the special region is disposed at a location which is almost or completely in non-contact with the silicon melt during an entire period of pulling a silicon crystal,
wherein the special region is made of vitreous silica whose raw material is primarily natural silica, and transparent layer other than the special region is made of vitreous silica whose raw material is primarily synthetic silica, and
the marking is constituted by dot-shaped recesses each having a depth of 0.2 mm or more and diameter of 0.5 to 3.0 mm, and said dot-shaped recesses are aligned on the inner wall along a horizontal direction.

2. The vitreous silica crucible of claim 1 , wherein the special region is installed between 5 mm downward from an edge portion of an opening of the vitreous silica crucible and 100 mm upward from the center of a bottom surface of the vitreous silica crucible, and the special region has a width ranging from 1 mm to 100 mm.

3. The vitreous silica crucible of claim 1 , wherein the marking is a laser marking.

4. The vitreous silica crucible of claim 1 , wherein the marking is a diamond tool marking.

Assignees

• Sudo Toshiaki
• Kishi Hiroshi
• Kodama Makiko
• Sumco Corp

Inventors

• Sudo Toshiaki
• Kishi Hiroshi
• Kodama Makiko

Classifications

• Y10T117/1032

  Seed pulling · CPC title

• C30B35/002 Primary

  Crucibles or containers · CPC title

• C03C19/00

  Surface treatment of glass, not in the form of fibres or filaments, by mechanical means (sand-blasting, grinding, or polishing glass B24) · CPC title

• C30B15/10 Primary

  Crucibles or containers for supporting the melt · CPC title

• C03C23/0025

  by a laser beam · CPC title