CN-122013316-A - Quartz glass crucible

CN122013316ACN 122013316 ACN122013316 ACN 122013316ACN-122013316-A

Abstract

The present invention relates to a crucible capable of sufficiently securing strength of an inner surface and an outer surface of the crucible. A quartz glass crucible is provided with a cylindrical side wall portion, a curved bottom portion, and a corner portion provided between the side wall portion and the bottom portion and having a curvature higher than that of the bottom portion, wherein the quartz glass crucible is provided with a1 st region provided from the inner surface of the crucible to the middle in the wall thickness direction, a2 nd region provided at a position further outside than the 1 st region in the wall thickness direction and having a strain distribution different from that of the 1 st region, and a3 rd region provided at a position further outside than the 2 nd region in the wall thickness direction and to the outer surface of the crucible and having a strain distribution different from that of the 2 nd region, the internal residual stresses of the 1 st region and the 3 rd region are compressive stresses, and the internal residual stresses of the 2 nd region include tensile stresses.

Inventors

Bei Yuanxian
SATO TAKASHI
Yoshiki Takuma

Assignees

胜高股份有限公司

Dates

Publication Date: 20260512
Application Date: 20181102
Priority Date: 20180228

Claims (7)

1. A quartz glass crucible provided with a cylindrical side wall portion, a curved bottom portion, and a corner portion provided between the side wall portion and the bottom portion and having a curvature higher than that of the bottom portion, the quartz glass crucible comprising: region 1, which is provided from the inner surface of the crucible to halfway in the wall thickness direction; A 2 nd region which is provided outside the 1 st region in the thickness direction and has a strain distribution different from that of the 1 st region, and A3 rd region which is located further outside than the 2 nd region in the wall thickness direction and is provided to the crucible outer surface, and which has a strain distribution different from that of the 2 nd region, The internal residual stress of the 1 st region and the 3 rd region is compressive stress, The internal residual stress of the 2 nd region comprises tensile stress, The 1 st region, the 2 nd region, and the 3 rd region are continuous in the circumferential direction, The surface roughness of the outer surface of the crucible is 10 μm or more and 50 μm or less in terms of Ra and 80 μm or more and 200 μm or less in terms of Rz, wherein Ra is an arithmetic average roughness measured according to Japanese Industrial Standard JIS B0601-2001, rz is a maximum height measured according to Japanese Industrial Standard JIS B0601-2001, The thickness of the 3 rd region is more than the thickness of the 1 st region, No fracture occurs when impacts are applied to the 16 points at the position of radius ra=200 mm in sequence.
2. The quartz glass crucible of claim 1, wherein, The internal residual stress of the 2 nd region does not contain compressive stress, The 2 nd region is adjacent to the 1 st region and the 3 rd region, respectively.
3. The quartz glass crucible of claim 1 or 2, wherein, The thickness in the wall thickness direction of the 1 st region is 1mm or more, preferably 3mm or more, from the inner surface of the crucible.
4. The quartz glass crucible of any of claims 1 to 3, wherein, The thickness in the wall thickness direction of the 3 rd region is 1mm or more, preferably 5mm or more from the outer surface of the crucible.
5. The quartz glass crucible of any of claims 1-4, wherein, The diameter of the indentation of the inner surface of the crucible is 5mm or less, preferably 1mm or less, when the punch is impacted against the inner surface of the crucible with a force of 300N.
6. The quartz glass crucible of any of claims 1-5, wherein, A transparent layer is arranged on the inner surface side of the crucible, a non-transparent layer is arranged on the outer surface side of the crucible, The 1 st area is arranged in the whole area of the thickness of the transparent layer.
7. The quartz glass crucible of any of claims 1-6, wherein, The size of the quartz glass crucible is more than 32 inches in outside diameter.

Description

Quartz glass crucible Technical Field The present invention relates to a quartz glass crucible. Background Monocrystalline silicon is produced by melting a silicon raw material (polycrystalline silicon) filled in a quartz glass crucible and pulling while bringing a seed crystal into contact with the molten polycrystalline silicon and rotating (CZ method: czochralski method). The quartz glass crucible used in the CZ method is manufactured by a rotary mold method. Specifically, the method for producing a silica glass crucible by the rotary mold method comprises a silica powder layer forming step of depositing silica powder having an average particle diameter of about 100-400 [ mu ] m on the inner side of a rotary carbon mold by centrifugal force to form a silica powder layer, and an arc melting step of arc melting the silica powder layer while depressurizing the silica powder layer from the mold side to form a silica glass layer. In the arc melting step, a so-called sealing layer is formed in which the entire surface of the quartz powder layer is thinned, then bubbles are removed by rapid decompression to form a transparent quartz glass layer (hereinafter, also referred to as a "transparent layer"), and then a bubble-containing quartz glass layer (hereinafter, also referred to as a "non-transparent layer") in which bubbles remain due to weakening of the decompression is formed. Thus, a quartz glass crucible having a double-layer structure, for example, a transparent layer on the inner surface side and a non-transparent layer on the outer surface side is formed. In this arc melting step, the quartz powder is first sintered, and after volume diffusion, the temperature further rises and grain boundaries disappear, thereby forming a network structure of vitrification and si—o—si. At this time, the sintering speed or the vitrification speed gradually changes. Specifically, for example, if the quartz powder is fine or the surface area is large even with the same volume, the sintering speed or the vitrification speed becomes high. If the quartz powder is fine, the space between adjacent quartz powder is also reduced, and sintering and vitrification are performed at a higher speed than removing bubbles by decompression, so that bubbles in the produced glass crucible are small and large. In this way, the molecular structure of the glass after arc melting, the bubbles contained therein, and the like are changed by the sintering speed or the vitrification speed. And solidifying the fused silica glass through a cooling process after the arc melting process. In this cooling step, the bonding system (for example, 6-membered ring or 8-membered ring) between silicon and oxygen or the size of the inter-atomic gap in the bonding structure between silicon and oxygen is changed by a cooling method such as a cooling rate or blowing of a cooling gas. For example, if the ratio of the existence of a large-sized ring structure such as an 8-membered ring is high, the voids are also increased. In this way, the bonding state of the material atoms changes in a complicated manner depending on the conditions such as the melting step and the cooling step in the crucible production, and therefore the distribution of the internal residual stress after the quartz glass crucible is cooled changes, thereby affecting the strength of the crucible. Patent document 1 discloses a method for producing silicon single crystal using a quartz glass crucible which can suppress deformation even when used under high temperature conditions for a long period of time. A quartz glass crucible used in the method for producing single crystal silicon is provided with a compressive stress layer comprising a transparent layer on the inner side and a bubble layer on the outer side thereof, wherein compressive stress remains on the inner surface side of the transparent layer, and a tensile stress layer adjacent to the compressive stress layer at a stress change rate of 0.17MPa/mm or more and 1.5MPa/mm or less, wherein tensile stress remains. Patent document 2 discloses a quartz glass crucible that can be easily taken out at the end of pulling at a high temperature with a strength Gao Judi. The quartz glass crucible comprises a quartz glass outer layer provided on the outer surface side of the crucible, a quartz glass inner layer provided on the inner surface side of the crucible, and a quartz glass intermediate layer provided between the quartz glass outer layer and the quartz glass inner layer. Patent document 3 discloses a quartz glass crucible that suppresses expansion of bubbles present in the quartz glass crucible and obtains a high single crystallization rate. In this quartz glass crucible, there is a compressive stress of one half of the breaking strength of the opaque layer in the transparent layer. Prior art literature Patent literature Patent document 1 Japanese patent laid-open publication No. 2017-001951 Patent document 2 International publication No. 2011/