# US 2014/0150714 A1 · Method of coating quartz crucible for growing silicon crystal, and quartz crucible for growing silicon crystal

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- Number: US 2014/0150714 A1
- Document ID: US20140150714A1
- Status: Published application
- Kind: A1
- Application number: 14/114,002
- Filed: 2011-12-02
- Published: 2014-06-05
- Earliest claimed: 2011-04-28
- Assignees: Ftb Research Institute Co., Ltd.
- Inventors: Yukichi Horioka; Shiro Sakuragi
- Web page: https://patentgrep.com/patent/US20140150714A1

## CPC

- C30B 15/10: Crucibles or containers for supporting the melt
- C03C 17/3417: {all coatings being oxide coatings}
- C30B 29/06: Silicon
- Y10T 117/1032: Seed pulling
- C30B: SINGLE-CRYSTAL GROWTH (by using ultra-high pressure, e.g. for the formation of diamonds, B01J3/06); UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL (zone-refining of metals or alloys C22B); PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (casting of metals, casting of other substances by the same processes or devices B22D; working of plastics B29; modifying the physical structure of metals or alloys C21D, C22F); SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (for producing semiconductor devices or parts thereof H10); APPARATUS THEREFOR
- C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A coating method for coating a crucible and a quartz crucible for growing a silicon crystal are provided. In the coating method, a bubble-free quartz layer which is 80 μm to 4 mm thick is formed on an inner surface of a crucible for growing a silicon crystal, and the surface of the bubble-free quartz layer is covered with alkaline earth hydroxide, following which heating is performed to a temperature at which the surface becomes devitrified. The surface may be covered by immersing the inner surface in a solution of the alkaline earth hydroxide. The heating may be performed before the crucible for growing silicon crystal is filled with a solid raw material to be melted.

## Claims

### Claim 1

A method of coating, comprising the steps of:
forming a bubble-free quartz layer having a thickness of 80 μm to 4 mm inclusive on an inner surface of a quartz crucible for growing a silicon crystal;
covering the surface of the bubble-free quartz layer with alkaline earth hydroxide; and
heating the surface to at least a temperature at which the surface becomes devitrified.

### Claim 2 (depends on 1)

The method of coating according to claim 1, wherein covering the surface of the bubble-free quartz layer with alkaline earth hydroxide is performed by immersing the inner surface in a solution including the alkaline earth hydroxide.

### Claim 3 (depends on 1)

The method of coating according to claim 1, wherein
the heating is performed before filling the crucible for growing a silicon crystal with a solid raw material to be melted.

### Claim 4

A quartz crucible for growing a silicon crystal, comprising:
a bubble-free quartz layer having a thickness of 80 μm to 4 mm, and
a devitrified coating formed by covering a surface of the bubble-free quartz layer with alkaline earth hydroxide and then heating the surface to at least a temperature at which the surface becomes devitrified.

### Claim 5 (depends on 2)

The method of coating according to claim 2, wherein
the heating is performed before filling the crucible for growing a silicon crystal with a solid raw material to be melted.