JP3394320B2 - Method for producing laminated quartz glass member having transparent layer and opaque layer - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a laminated quartz glass member having a transparent layer and an opaque layer, and particularly to a bell jar for semiconductor production, a diffusion furnace core tube, and a flange portion constituting a boat holding jig. The present invention relates to a method for manufacturing a flange portion of a quartz glass container.

[0002]

2. Description of the Related Art Conventionally, quartz glass is high in purity and excellent in heat resistance. Therefore, jigs and tools for semiconductor manufacturing, such as bell jars for semiconductor manufacturing, diffusion furnace core tubes, and flanges for boat holding jigs, etc. It has been used as a material for attached quartz glass containers. In this jig for semiconductor manufacturing, radiant heat is generated in the container, which heat-deteriorates the sealing member at the end of the container, so it is common to configure the flange part with opaque quartz glass containing fine bubbles. there were. However, the opaque quartz glass contains many air bubbles, which are exposed on the sealing surface, and even if a packing material is used, the flange portion cannot be completely sealed. Then, when the flange part was strongly tightened, it was easily broken from the place where the material was glass. In order to solve these drawbacks, a laminated quartz glass member having a transparent quartz glass layer formed on an opaque quartz glass layer has been proposed in Japanese Utility Model Publication No. 1-43164.

However, since the transparent glass plate is welded to the flange portion of the laminated quartz glass member, large bubbles remain at the interface between the transparent layer and the opaque layer at the time of welding, or cracks due to partial cooling are generated and cracked. That was often the case.

[0004]

In order to solve these problems, the inventors of the present invention have conducted diligent research, and as a result, placed a transparent quartz glass plate in a heat-resistant mold and deposited quartz powder on it. The present invention has been completed by finding that a laminated quartz glass member excellent in sealing property can be obtained by heating and melting it in an inert gas atmosphere.

That is, it is an object of the present invention to provide a method for producing a laminated quartz glass member having a flat sealing surface and no large bubbles at the interface.

Another object of the present invention is to provide a method of manufacturing a flanged container which has a good heat insulating property and an excellent sealing property.

[0007]

According to the present invention for achieving the above object, a transparent quartz glass body having a surface roughness of 20 to 100 μm is arranged in a heat resistant mold, and quartz powder is deposited on the transparent quartz glass body to make it inert. The present invention relates to a method for producing a quartz glass member having a transparent layer and an opaque layer that are heated and melted in a gas atmosphere.

As the heat resistant mold used in the above-mentioned manufacturing method, a cylindrical carbon mold is suitable. As shown in FIG. 1, a disk-shaped transparent quartz glass body 1 is placed in this cylindrical mold, and quartz powder 2 is deposited on the transparent quartz glass body 1, which is heated and melted to obtain the laminated quartz glass member shown in FIG. Can be manufactured. In the above-mentioned manufacturing method, when the transparent quartz glass is the doughnut-shaped transparent quartz glass body 1, a carbon rod-shaped column 4 is erected at the center thereof, and a space surrounded by the mold 3, the transparent quartz glass 1 and the rod-shaped column 4 is formed. By depositing the quartz powder 2 and heating and melting it, a container with a flange can be suitably manufactured. The surface roughness of the transparent quartz glass body 1 is preferably 20 to 100 μm. By having this surface roughness, the contact area between the transparent quartz glass body and the quartz powder increases,
Bonding without generating bubbles during melting and heating. If the surface roughness is less than the above range, the surface is smooth and the bonding is not tight, and if it exceeds the above range, large bubbles are generated on the bonding surface, resulting in poor sealing performance.

The quartz powder 2 deposited on the transparent quartz glass body is preferably a quartz powder containing 5% by weight or more of particles having a particle diameter of 100 μm or less. This quartz powder is in an inert gas atmosphere at 1,600 to 2,000 ° C., preferably 1,700 to
Opaque glass containing fine closed cells is obtained by heating and melting in the temperature range of 1,800 ° C. Quartz powder has a particle size of 1
In the case of containing less than 5% by weight of particles of 00 μm or less,
Large air bubbles are formed, resulting in poor heat insulation.

When the heating and melting temperature range is less than 1,600 ° C., sintering is insufficient and cracks are likely to occur.
On the contrary, when the melting temperature exceeds 2,000 ° C., the melting proceeds excessively, the opacity of the opaque portion is lowered, and the heat ray shielding effect is lowered. Further, the atmosphere is preferably an inert gas atmosphere, and for example, by heating and melting under vacuum, the gas in the powder portion is removed and the glass is transparentized to give an opaque quartz glass. The inert gas used is most preferably inexpensive N ₂ gas, but is not particularly limited thereto.

When the above manufacturing method is used for manufacturing the flange portion of the flanged container for semiconductor manufacturing, quartz powder is subjected to a purification treatment according to a purification method described in, for example, US Pat. No. 4,983,370, The alkali metal element concentration in the opaque quartz glass is 0.2 ppm or less, and the OH group concentration is 10 ppm.
It is preferable to prevent the contamination of the semiconductor by setting the concentration of ppm or less, the concentration of iron element to 0.1 ppm or less, the concentration of magnesium element to 0.05 ppm or less, and the concentration of zirconium element to 0.1 ppm or less. Further, it is preferable that the manufactured laminated quartz glass member is flat-polished and baked to improve the sealing property.

[0012]

EXAMPLES The present invention will be described in detail below with reference to examples.

Example 1 In a cylindrical carbon mold 3 having an inner diameter of 330 mm and a height of 300 mm, an outer diameter of 330 m having a surface roughness of 40 μm shown in FIG.
A donut-shaped transparent quartz glass body 1 having a size of m × 10 mm is arranged, and a carbon rod-shaped support column 4 having an outer diameter of 170 mm × height of 300 mm is erected in the central portion thereof, and a carbon mold 3, a transparent glass plate 1 and a rod-shaped member 4 are provided. The enclosed space was filled with natural crystalline quartz powder 2 having the purity shown in Table 1 and the particle size shown in Table 2 up to a depth of 200 mm, and placed in a vacuum furnace as it was.
Flow ₂ gases at a flow rate of 5 l / min, from room temperature to 1,7
Up to 50 ° C, the temperature is raised at a rate of 10 ° C / min or less to 1,7
It was heated and melted at a temperature of 50 ° C. for 1 hour. After turning off the heater, the temperature was lowered to room temperature and the product was taken out. The transparent surface of the glass body taken out was flat-ground to a maximum of 3 mm and a minimum of 1 mm to form a transparent layer. Then, the quartz glass body is made to have an outer diameter of 320 mm.
After being processed to have an inner diameter of 180 mm and a thickness of 15 mm, the transparent surface was baked to prepare a quartz glass member. The transparent layer of the member is flat and has a surface roughness of 2 as shown in FIG.
It was less than μm. In addition, generation of bubbles exceeding 100 μm was not confirmed at the interface between the transparent layer and the opaque layer.

[0014]

[Table 1]

[0015]

[Table 2]

Comparative Example 1 An opaque quartz glass flange was prepared in the same manner as in Example 1 except that the transparent quartz glass body was not placed. The obtained opaque glass layer had a bubble diameter of 10 to 160 μm, a total bubble volume in the opaque quartz glass of 3 to 10%, and a total bubble area per 100 cm ^{3 of the} opaque quartz glass of 800 to.
It was an opaque glass layer of 1,500 cm ² . After flattening the sealing surface, the surface roughness was measured, and as shown in FIG. 5, a surface roughness of about 100 μm was shown. Further, it was baked and finished, but its surface roughness was only about 10 μm as shown in FIG.

Comparative Example 2 A transparent quartz glass ring having the same dimensions was fused and welded to a sealing surface of a flange member made of opaque quartz glass having an outer diameter of 320 mm and an inner diameter of 180 mm while melting with an oxyhydrogen burner. Several bubbles with a maximum size of 400 μm were generated at the interface. In addition, during welding, cracks were generated from the part that was rapidly cooled by irradiation with a burner flame, and many of them were damaged as a whole.

Comparative Example 3 An opaque quartz glass flange with a transparent quartz glass layer was prepared in the same manner as in Example 1 using a transparent quartz glass body having a surface roughness of 2 μm or less. However, at the interface between the transparent glass layer and the opaque glass layer, bubbles of up to about 7 mm frequently occurred.

Comparative Example 4 A transparent quartz glass body having a surface roughness of 40 μm was used, and a natural crystalline quartz powder from which quartz glass powder having a particle size of 150 μm or less was removed was used. An opaque quartz glass flange with a quartz glass layer was created. At the interface between the transparent layer and the opaque layer, many bubbles with a diameter of about 300 μm were generated.

[0020]

According to the manufacturing method of the present invention, it is possible to manufacture a quartz glass member having a flat surface having a surface roughness of 2 μm or less and having an excellent sealing property. In particular, the flanged container of the semiconductor manufacturing flanged container obtained by the manufacturing method of the present invention was excellent in the sealing property of the flange portion, and the semiconductor was not polluted with high purity.

[Brief description of drawings]

FIG. 1 is a schematic view of a manufacturing method of the present invention.

FIG. 2 is a laminated quartz glass member obtained by the manufacturing method of the present invention.

FIG. 3 is a state diagram of the surface roughness of the transparent quartz glass body used in the manufacturing method of the present invention.

FIG. 4 is a state diagram of the surface roughness after the surface of the transparent quartz glass obtained by the manufacturing method of the present invention is flattened.

FIG. 5 is a surface state diagram of a transparent quartz glass body having a surface roughness of 100 μm.

6 is a state diagram of the surface roughness after the surface of the transparent quartz glass of FIG. 5 is flattened.

[Explanation of symbols]

1 Transparent quartz glass plate 2 Quartz powder 3 Heat resistant type 4 rod-shaped support 5 Transparent quartz glass layer 6 Opaque quartz glass layer

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toru Yokota 88 Kawakubo, Kanaya, Tamura-cho, Koriyama-shi, Fukushima Shin-Etsu Quartz Co., Ltd. Quartz Research Laboratory (56) Reference JP-A-4-50126 (JP, A) ( 58) Fields investigated (Int.Cl. ⁷ , DB name) C03B 20/00 C03B 19/01 C03B 19/09 C03C 17/04 B32B 17/06

Claims (4)

(57) [Claims] 1. Surface roughness in a heat resistant mold is 20 to 100 μm.
1. A method for producing a laminated quartz glass member having a transparent layer and an opaque layer, which comprises arranging the transparent quartz glass body of claim 1, depositing quartz powder on the transparent quartz glass body, and heating and melting in an inert gas atmosphere. 2. The surface roughness of the heat resistant mold is 20 to 100 μm.
Of the donut-shaped transparent quartz glass body, a carbon rod-shaped body was installed in the center of the donut-shaped transparent quartz glass body, and the space surrounded by the mold, the rod-shaped body, and the transparent quartz glass body was filled with quartz powder. Then, a method for producing a laminated quartz glass member having a transparent layer and an opaque layer, which comprises heating and melting in an inert gas atmosphere. 3. The quartz powder is a powder containing 5% by weight or more of particles having a particle diameter of 100 μm or less.
Alternatively, the method for producing a laminated quartz glass member according to the item 2. 4. A heating and melting temperature of 1,600 to 2,000 ° C.
The method for producing a laminated quartz glass member according to claim 1 or 2, characterized in that