US 12,116,692 B2
Quartz glass crucible
Takeshi Fujita, Akita (JP); Ken Kitahara, Akita (JP); Tomokazu Katano, Tokyo (JP); and Eriko Kitahara, Akita (JP)
Assigned to SUMCO CORPORATION, Tokyo (JP)
Appl. No. 17/413,925
Filed by SUMCO CORPORATION, Tokyo (JP)
PCT Filed Dec. 16, 2019, PCT No. PCT/JP2019/049119
§ 371(c)(1), (2) Date Jun. 14, 2021,
PCT Pub. No. WO2020/137647, PCT Pub. Date Jul. 2, 2020.
Claims priority of application No. 2018-244360 (JP), filed on Dec. 27, 2018; and application No. 2018-244362 (JP), filed on Dec. 27, 2018.
Prior Publication US 2022/0090290 A1, Mar. 24, 2022
Int. Cl. C03B 15/10 (2006.01); C03B 19/09 (2006.01); C03C 3/06 (2006.01); C03C 4/10 (2006.01); C30B 15/10 (2006.01)
CPC C30B 15/10 (2013.01) [C03B 19/095 (2013.01); C03C 3/06 (2013.01); C03C 4/10 (2013.01); C03C 2201/02 (2013.01); C03C 2204/00 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A pre-use 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 bubbles at a bubble content of more than 0.1 vol %; and
a semi-molten layer formed outside the bubble layer and having a rugged surface, which is a layer solidified by cooling raw material silica powder in a partially melted state,
wherein a ratio of an infrared transmissivity of the corner portion at a maximum thickness position of the corner portion to an infrared transmissivity of the side wall portion is 0.3 or more and 0.99 or less, and
an absolute value of a rate of change in infrared transmissivity in a height direction along a wall surface of the crucible from a center of the bottom portion toward a rim of the crucible is 3%/cm or less,
wherein the infrared transmissivity of the crucible is a value measured when removing the semi-molten layer from the crucible for measurement purposes.