JPH0735384Y2 - Assembled warmer - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-retaining cylinder for mounting a wafer support boat in a vertical heat treatment apparatus for heat-treating a silicon wafer in a furnace core tube. The present invention relates to a heat insulating cylinder having excellent heat insulating properties and heat shielding properties for a device sealing portion, and having sufficient strength to support a wafer mounting boat even at high temperatures.

[0002]

2. Description of the Related Art A heat insulating cylinder is required to have heat insulating and heat insulating properties in an upper heat treating region in a furnace core tube and heat shielding property to a device sealing portion in a vertical heat treating apparatus, and a wafer mounting boat is required to be mounted on the heat insulating cylinder. A strength that can be supported is required. In accordance with such required performance, conventionally, a heat-insulating cylinder filled with long-fiber-shaped quartz glass wool has been used. However, such a heat insulating tube is filled with quartz glass so that the inside of the heat insulating tube does not explode during gas treatment, and then the inside of the heat insulating tube is evacuated.

As described above, the heat insulating cylinder having such a structure is subjected to the welding and sealing process while evacuation for preventing the explosion. However, this welding work is quite difficult,
In addition to requiring skill, there is a practical problem that the danger of explosion is not eliminated even if a vacuum is drawn, and the strength at high temperature is low because the inside of the heat retaining cylinder is evacuated. In terms of, it is industrially extremely disadvantageous.

[0004]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a heat insulating tube which does not need to be evacuated and which is excellent in operability in manufacturing and assembling. Another object of the present invention is to provide a practically desirable heat insulating cylinder having excellent heat insulating heat insulating property and boat supporting strength. The present inventor has carried out trial research on the above problems and developed a heat insulating cylinder having excellent practicality which effectively overcomes the above problems.

[0005]

That is, the present invention is a member in which a silica glass cylindrical body for mounting a wafer support boat is integrally formed on the upper side of a disk-shaped silica glass plate body,
It has an outer diameter that is almost the same as the inner diameter of the cylinder,
/ 2 to 3/4, preferably a cylindrical silica glass porous body having a length of about 5/8 and capable of being inserted into the inside of the cylindrical body, and an inner diameter substantially the same as the outer diameter of the cylindrical body. The gist of the present invention is a prefabricated heat insulating cylinder formed by combining a cylindrical silica glass porous body fitted to the outside of the cylindrical body having the same length as the cylindrical silica glass porous body.

The heat insulation cylinder of the present invention is a combination of a plate member, a cylindrical silica glass porous body, and a cylindrical silica glass porous body, which are a combination of a silica glass disk-shaped substrate and a cylindrical body as described above. It will be Then, the disk-shaped silica glass cylindrical body is, for example, a transparent plate material having a diameter of about 150 to 300 mm and a thickness of about 5 to 15 mm, and a silica glass cylindrical body of the same thickness is integrally formed on the upper surface thereof. The bottom of the disk-shaped substrate, which is attached, is usually preferably integrally formed with a thread bottom as a supporting leg.

However, since the upper part of the cylindrical body is exposed to a considerably high temperature, it is preferable to form the cylindrical part with a pipe made of silicon carbide having an excellent heat resistance temperature. In this case, for example, The lower end edge of the silicon carbide pipe is cut out on the inner side, and the upper end edge of the silica cylinder is cut off on the outer side to be fitted integrally in a phase cutout form to form a single pipe. A silica glass cylinder having such a combined structure is particularly desirable in practice, and the present invention includes such a preassembled heat insulating cylinder.

Such a silica glass plate member is preferably made of substantially transparent silica glass. In particular, the yarn bottom and the cylinder for supporting the boat stably support the wafer boat. It is important to form the ring-shaped yarn bottom with sufficient strength, and it is usually desirable to make the ring-shaped yarn bottom sufficiently larger than the diameter of the upper cylindrical body in order to enhance the stability of the heat retaining cylinder.

Further, the cylindrical silica glass porous body and the cylindrical silica glass porous body used in the heat insulating cylinder of the present invention are mainly independent cells in view of their heat insulating heat retention and mechanical strength at high temperature. Often consists of
The apparent density is preferably about 0.1 to 1 g / cm ³ . If the density of the porous body is too low, it becomes brittle and easily collapses, which causes dust, and if it is too high, it is not only preferable because it is heavy and the heat-insulating and heat-retaining property is deteriorated.

The cylindrical silica glass porous body inserted into the inside of the cylinder can be inserted into and withdrawn from the cylinder, and is formed to have an almost same outer diameter close to the inner diameter of the cylinder. An operation member can be attached to the upper surface to facilitate the insertion and the withdrawal. Further, it is preferable that the upper surface of the cylindrical porous body is located slightly below the high temperature region for heating the wafer supported by the boat, and it is usually 1/2 of the height of the cylindrical body. ~ 3/4, especially 5 /
It is practical to set the length to about 8.

Further, the cylindrical silica glass porous body applied to the outside of the cylindrical body has an inner diameter as close as possible to the outer diameter of the cylindrical body which can be detachably fitted to the cylindrical body. In addition, the length thereof is preferably formed to the same level as the height of the inner cylindrical silica glass porous body. The thickness is related to the difference between the diameter of the furnace core tube and the diameter of the cylindrical body and the apparent specific gravity, but it is practical to increase the thickness as long as it does not hinder the operation.

[0012]

[Function] The prefabricated heat insulation cylinder composed of three members of the present invention is
It is extremely easy to operate because it only has to be fitted and assembled in a predetermined state, and it is extremely practical because it has excellent heat insulating and heat insulating properties in the wafer heat treatment area and heat shielding and strength to the equipment sealing part. is there. Further, these porous bodies have an advantage that they can be used as they are as an assembly member in the heat treatment of the same kind of continuous wafers without being attached and detached for each treatment batch.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, referring to the attached drawings, the assembling type heat retaining tube of the present invention will be described in more detail by way of examples. FIG. 1 is a vertical cross-sectional view of an example of a preferable assembled heat insulating cylinder of the present invention.

In the figure, a disk-shaped silica glass plate 1
The ring-shaped thread bottom 2 is on the lower side and the wafer support button is on the upper side.
A silica glass cylindrical body 3 on which the torso is mounted is integrally attached, and an upper portion of the cylindrical body is formed of a silicon carbide cylindrical body 4 having the same shape, and they are fitted and integrated in a mutually notched shape. The silica glass plate member has a cylindrical silica porous body 5 having a height of about 5/8 of the height of the cylindrical body.
And the cylindrical silica porous body 6 are fitted and assembled inside and outside the cylindrical body 3, respectively, and the wafer mounting boat (not shown) is held on the upper side of the silicon carbide cylindrical body 4.

[0015]

EFFECTS OF THE INVENTION The three-part assembly type heat retaining tube of the present invention is easy to manufacture the individual members and has excellent operability for assembling, and has excellent heat insulating and heat retaining ability and boat supporting strength. Not only can large wafers be heat-treated, but they also have a long service life, so their industrial value is extremely high.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an assembled state of an example of the assembly-type heat retaining cylinder of the present invention.

[Explanation of figure]

 1 Disk-shaped silica glass plate 2 Ring-shaped thread bottom 3 Silica glass cylinder 4 Silicon carbide cylinder 5 Cylindrical silica foam 6 Cylindrical silica foam

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Claims (2)

[Scope of utility model registration request] 1. A wafer is provided on the upper side of a disk-shaped silica glass plate.
(C) A member integrally formed with a silica glass cylinder on which a support boat is mounted, having an outer diameter substantially the same as the inner diameter of the cylinder, and a length of 1/2 to 3/4 of the length of the cylinder. And a cylindrical silica glass porous body that can be inserted inside the cylindrical body and that has the same inner diameter as the outer diameter of the cylindrical body and the same length as the inner cylindrical silica glass porous body. Assembling type heat retaining cylinder made by combining cylindrical silica glass porous bodies fitted to the outside of the. 2. The heat insulating cylinder according to claim 1, wherein the silica glass cylinder is formed of a composite cylinder formed by forming a part of the silica glass pipe with a silicon carbide pipe.