JPS61292911A - Heat treatment device - Google Patents

Abstract

PURPOSE:To augment the rigid strength of a tube wall, and to support its own weight of the tube wall sufficiently against the lowering of rigid strength due to heating by forming a flexural strength augmenting section to a process tube. CONSTITUTION:The tube wall 1a of a process tube 1 is shaped in a corrugated form projected and recessed in the radial direction. Since strength against the bending stress of its own weight is made higher than the tube wall 1a is formed to one plate shape, its own weight can be supported sufficiently. Flexural strength increasing sections 9 are arranged in approximately parallel with the direction of the center line of the process tube 1, and staggered in the circumferential direction. Accordingly, flexural strength in the direction of a span in the whole process tube is augmented enough, thus positively preventing possibility in which the process tube 1 hangs down at both end sections.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a heat treatment technology, particularly an improved technology for process tubes, and is a technology that is effective when used to perform diffusion treatment on wafers, for example, in the manufacture of semiconductor devices. Regarding.

[Background technology]

In the manufacture of semiconductor devices, the wafer is used as a diffusion device to perform diffusion processing on the wafer.The wafer is carried into a cylindrical process tube made of quartz glass, and the inside of the process tube is heated by a heater to initiate the desired diffusion reaction. A device is conceivable that is configured to cause .

However, in such a diffusion device, when the diameter of the process tube increases as the diameter of the wafer increases, the cylindrical wall of the process tube becomes unable to support its own weight due to a decrease in its own rigidity due to heating. The inventor of the present invention has revealed that there is a problem that deformation of the process tube occurs.

In addition, as an example of a diffusion device, a stock% formula% is used. [Object of the Invention] An object of the present invention is to provide a heat treatment technique that can prevent deformation of a process tube due to an increase in diameter. .

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Summary of the invention]

A brief overview of typical inventions disclosed in this application is as follows.

That is, by forming a bending strength-enhancing part in the process tube by meandering the cylindrical wall itself so that it goes in and out in the radial direction, the rigidity of the cylindrical wall is increased,
This structure is designed to sufficiently support the weight of the cylinder wall against a decrease in rigidity and strength due to heating.

[Embodiment 1] FIG. 1 is a longitudinal sectional view showing a diffusion device as an embodiment of the present invention, and FIG. 2 is an enlarged sectional view taken along line nn in FIG. 1.

In this embodiment, this diffusion device includes a process tube 1 formed of quartz glass or the like into a substantially cylindrical shape, and an internal chamber of this process tube 1 substantially forms a processing chamber 2. A heater 4 is disposed concentrically outside the process tube 1, and the heater 4 uniformly heats the processing chamber 2 through the process tube 1.

A furnace port 3 is formed at one end opening of the process tube 1 for loading and unloading a plurality of wafers 5 as processing objects in a boat-shaped jig 6 in a lined manner. It is designed to be opened and closed. A gas supply port 8 is opened at the other end of the process tube 1, and the gas supply port 8 is adapted to introduce a processing gas such as a carrier gas, wet oxygen, etc., which flows impurities as a diffusion source.

The process tube 1 is formed with a plurality of bending strength reinforcement parts 9 formed by meandering into a wave shape so as to go in and out of the cylindrical wall 1a itself in the radial direction, and each bending strength reinforcement part 9 is formed in the process tube 1, and is arranged substantially parallel to the center line direction of 1 and meandering in the circumferential direction.

Next, the action will be explained.

When the heater 4 is energized and the processing chamber 2 of the process tube 1 is set to a predetermined processing temperature and atmosphere, a plurality of wafers 5 as processing objects are placed on a quartz glass jig 6 and processed. It is carried into the inside of the tube l from the furnace mouth 3.

At this time, the jig 6 is slid on the inner surface of the process tube 1, but since the cylindrical wall 1a of the process tube 1 is formed into a corrugated shape by providing the bending strength reinforcement part 9, the jig 6 and the process The contact area with the inner surface of the tube 1 is reduced, and dust generation due to sliding is suppressed.

When a predetermined gas is supplied to the processing chamber 2 from the gas supply port 8, the wafer 5 is heated to a predetermined temperature in a predetermined atmosphere, thereby performing a desired diffusion process.

At this time, since the cylindrical wall 1a of the process tube 1 is formed in a corrugated shape that goes in and out in the radial direction, the gas flow becomes turbulent, and the gas comes into uniform contact with the five wafers and within the wafer 5. , a uniform diffusion process is performed.

By the way, when the diameter of the process tube increases as the diameter of the wafer increases, the cylindrical wall of the process tube becomes unable to support its own weight due to a decrease in its own rigidity due to heating, resulting in deformation of the process tube. The inventor of the present invention has discovered that there is a problem in that.

However, in this embodiment, the process tube I is formed with a plurality of bending strength reinforcement parts 9 formed by meandering into a waveform shape so as to enter and exit the cylindrical wall 1a itself in the radial direction. This will prevent the process tube 1 from deforming.

That is, by forming the cylindrical wall 1a of the process tube 1 into a corrugated shape that goes in and out in the radial direction, the strength against bending stress due to its own weight is increased compared to when the cylindrical wall 1a is formed into a single plate shape. Therefore, it can sufficiently support its own weight. Furthermore, since the bending strength increasing portion 9 is arranged approximately parallel to the center line direction of the process tube l and meandering in the circumferential direction, the bending strength of the entire process tube 1 in the span direction is sufficiently increased.
The risk of the process tube 1 hanging down at both ends is reliably prevented.

Therefore, even if the diameter of the process tube 1 increases, deformation of the process tube 1 can be prevented.

[Embodiment 2] FIG. 3 is a front view of a process tube showing another embodiment of the present invention.

The second embodiment differs from the first embodiment in that the bending strength increasing portion 9A is arranged in a spiral shape with respect to the process tube IA.

According to the second embodiment, since the bending strength increasing portion 9A is formed in a spiral shape, the process tube cylinder 11a
Resistance to crushing stress and process tube I
The resistance to bending stress in the span direction of A is increased.

[Embodiment 3] FIG. 4 is a front view of a process tube showing another embodiment of the present invention.

The third embodiment differs from the first embodiment in that the bending strength increasing portion 9B is arranged substantially perpendicular to the centerline of the process tube IB and meandering in the direction of the centerline.

According to the second embodiment, since the bending strength increasing portion 9B is disposed substantially perpendicular to the center line, the resistance against the crushing stress of the process tube cylindrical wall 1a is greatly increased.

〔effect〕

(11) By forming a plurality of bending strength reinforcement parts on the process tube by meandering them into a corrugated shape so as to go in and out of the cylindrical wall itself in the radial direction, the cylindrical wall is formed into a single plate shape. Since the bending strength of the cylindrical wall and the process tube as a whole can be increased compared to the case where the process tube is deformed by its own weight, it is possible to prevent the process tube from deforming due to its own weight.

(2) By preventing deformation of the process tube due to its own weight, it is possible to increase the diameter of the process tube, so it is possible to increase the diameter of objects to be processed such as wafers.

(3) Since the bending strength of the process tube can be increased without increasing the thickness of the cylindrical wall, it is possible to suppress an increase in the weight of the process tube and to save resources.

(4) By forming the cylindrical wall of the process tube into a meandering shape that goes in and out in the radial direction, it is possible to reduce the contact area with tools that slide inside the process tube, thereby suppressing dust generation due to sliding. be able to.

(5) By forming the cylindrical wall of the process tube into a meandering shape that goes in and out in the radial direction, the flow of gas inside the process tube becomes turbulent, allowing the gas to come into uniform contact with the object to be processed. , the processing can be made uniform. Although the invention made by the present inventor has been specifically explained based on Examples above, the present invention is not limited to the above-mentioned Examples, and the present invention is not limited to the above-mentioned Examples. It goes without saying that various changes can be made.

For example, the bending strength enhancing portion is not limited to forming the cylindrical wall of the process tube into a meandering waveform that goes in and out in the radial direction, but may also be formed into a substantially trapezoidal cross-sectional shape or a substantially rectangular cross-sectional shape.

[Application field]

The above explanation has mainly been about the application of the invention made by the present inventor to diffusion snow making, which is the background field of application, but the invention is not limited to this, and is not limited to low pressure CVD equipment, annealing equipment, etc. It can be used in all heat treatment equipment.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing a diffusion device as an embodiment of the present invention, Fig. 2 is an enlarged sectional view taken along line nn in Fig. 1, and Fig. 3 is an embodiment of a pond according to the present invention. FIG. 4 is a front view of a process tube showing another embodiment of the present invention. 1, IA, IB...process tube, 1a...m
Wall, 2...processing chamber, 3...furnace opening, 4...heater,
5... Wafer (workpiece) 6... Jig, 7... Cap, 8... Gas supply port, 9.9A, 9B... Bending strength reinforcement part. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. A heat treatment apparatus characterized in that a process tube is formed with a plurality of bending strength enhancing sections meandering so as to extend in and out of the cylindrical wall itself in the radial direction. 2. The heat treatment apparatus according to claim 1, wherein the meandering shape of the bending strength increasing portion is formed in a wave shape. 3. The heat treatment apparatus according to claim 1, wherein the bending strength increasing portions are arranged substantially parallel to the centerline direction of the process tube and meandering in the circumferential direction. 4. The heat treatment apparatus according to claim 1, wherein the bending strength increasing portions are each arranged in a spiral shape with respect to the process tube. 5. The heat treatment apparatus according to claim 1, wherein the bending strength increasing portions are arranged substantially perpendicular to the center line of the process tube and meander in the direction of the center line. .