JPH0625000Y2 - Core tube structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a furnace core tube structure used in a semiconductor heat treatment apparatus for performing oxidation diffusion and other heat treatment of a semiconductor wafer.

“Prior art” Conventionally, with the semiconductor wafer group aligned in the heat treatment area in the furnace core tube formed by surrounding the heating element around the furnace core tube, the processing gas is introduced into the furnace core tube from the gas introduction tube. By heating the semiconductor wafer group while flowing, a semiconductor heat treatment apparatus configured to perform oxidation diffusion and other heat treatments on the wafer surface is known, and in this type of apparatus, the process gas flowing in the furnace core tube is In order to contact not only the wafer surface but also the inner wall of the furnace core tube, the oxide film laminated on the wafer surface adheres to the furnace core tube side, and when the adhesion exceeds a certain thickness, the inner wall becomes flakes. Peeling off significantly reduces the product yield.

For this reason, in the apparatus having the above-mentioned configuration, it is necessary to periodically remove the furnace core tube from the apparatus and wash it. As the size and length increase, the size of the cleaning tank and the like must be increased correspondingly, and it becomes difficult to sufficiently clean the inner part of the furnace core tube.

For this reason, in JP-A-58-123719, there is proposed a device in which the furnace core tube is divided into two in a direction orthogonal to the axis and the divided tubes can be connected by rubbing. .

[Problems to be Solved by the Invention] However, in the related art, the above-mentioned publication No. 4
As shown in FIG. 3 and FIG. 3, since the connecting portion of the divided pipes is located in the heat treatment area formed by surrounding the heating element, the flow of the processing gas changes at the divided portion. However, it may be difficult to form a uniform film.

When the temperature in the heat treatment zone rises to 900 to 1200 ° C, the furnace core tube itself may be softened and deformed by heat, and it may be difficult to accurately divide and reassemble.

Also, when trying to join in the above high temperature range, the heat resistant temperature of a heat resistant seal member such as a silicone resin O-ring is
Since it is 200 ° C to 300 ° C, it is naturally impossible to use these sealing members. As a result, in the above-mentioned conventional technology, there is no choice but to adopt a sealing structure by slicing quartz glass materials together. However, this cannot avoid the deterioration of the sealing performance as well as the thermal deformation of the end portion of the tubular body, and it cannot be used at all in a device using so-called toxicity, flammability or other dangerous gas.

Therefore, the inventor of the present invention, even in the apparatus in which the furnace core tube is divided into a plurality of tube bodies as described above, does not hinder the formation of a uniform film, and only the portion that requires the most cleaning or the portion with poor durability is used. A furnace core tube structure that can maintain a stable sealability for a long period of time while preventing the thermal deformation of the tube body that constitutes the furnace core tube while making it separable was studied.

On the other hand, in the semiconductor heat treatment apparatus having the above configuration, the semiconductor wafer group is faced in the furnace core tube on the gas introduction side,
A disk-shaped gas flow buffering member called a so-called buffer plate is arranged, and while the processing gas introduced into the furnace core tube is once collided with the buffering member to be dispersed, each surface of the wafer arranged in the heat treatment area is dispersed. A diffusion furnace or other device configured to evenly supply the processing gas, and in particular, a heat insulating tube having a heat insulating structure facing the heat treatment area in order to uniformize the heating temperature distribution in the heat treatment area. There are devices and the like arranged in the furnace core tube.

Many of these members are configured to be installed independently in the furnace core tube. However, with such a configuration, in addition to the boat loading / unloading operation for aligning and holding the semiconductor wafers, each of the members also has a predetermined position at each heat treatment step. Since it has to be carried out, the carrying-in / carrying-out operation is complicated, and particles are generated due to rubbing during the carrying-in / carrying-out operation to lower the product yield.

Further, in order to secure the extra space necessary for carrying in and out the member, the diameter of the member must be made considerably smaller than that of the furnace core tube, and as a result, many void spaces are formed on the outer circumference of the member. Formed, it is difficult to perform preferable control.

Further, in order to facilitate the loading and unloading of the member, there is one that is integrally mounted on both ends of the boat sandwiching the wafer storage position and carries in and out with the boat. In addition to being unable to eliminate the latter drawback of forming a large number of void spaces, the boat length increases correspondingly, especially when the member is installed in an area deviating from the wafer heat treatment area, and Since the burden of weight becomes heavy, there is a problem that the equipment becomes large.

In view of the above-mentioned drawbacks of the prior art, the object of the present invention is to eliminate the loading / unloading operation of a control body such as a buffer plate or a heat insulating cylinder for controlling the reaction atmosphere in the furnace core tube, and to provide a large amount on the outer circumference of the control body. SUMMARY OF THE INVENTION It is an object of the present invention to provide a furnace core tube structure capable of completely eliminating the basic drawback that the void space is formed.

"Means for Solving the Problems" In view of the above problems, the present invention is characterized in that, as shown in FIG. 4, a buffer plate, a heat insulating tube or the like for controlling the reaction atmosphere in the furnace core tube 1 is used. The first feature is that the atmosphere control body 16 is formed to have a diameter substantially the same as that of the cylindrical body having one or a plurality of through holes 161 for allowing the processing gas to pass therethrough, particularly the furnace core tube 1.

The second characteristic is that the outer peripheral wall 162 of the control body 16 is
However, it is configured so as to form a part of the outer peripheral wall 151 constituting the furnace core tube 1.

In this case, the control body 16 may be integrally connected to the tube body 15 that constitutes the furnace core tube 1 or may be fitted so as to be divided and opened, but the furnace core tube 1 and the control body 16 are cleaned. The latter is advantageous in terms of facilitating the above.

Due to its function, the control body 16 is preferably provided in an area outside the heat treatment area A of the furnace core tube 1 accommodating the wafer 3. In this case, in order to facilitate loading / unloading of the semiconductor wafer 3, It is better to place it on the opposite side.

[Operation] According to the present invention, the atmosphere control body 16 such as the buffer plate, the heat insulating cylinder or the like is preferably divided into the tube bodies 15 forming the furnace core tube so as to form a part of the tube wall of the furnace core tube 1. Since it is releasably fitted and fixed, it is possible to accurately and normally position and arrange the control body 16, and as a result, it is not necessary to carry the control body 16 in and out every heat treatment step. At the same time, it is possible to completely suppress the generation of particles due to rubbing and the like during the loading / unloading operation, and the product yield is significantly improved.

Further, since the control body 16 can completely shut off the reaction chamber such as the heat treatment area A and the combustion section (tail tube) 14 side, when the control body 16 is used as a heat insulating cylinder, many of it is on the outer circumference. The heat retaining effect is extremely large as compared with the prior art having a void space, and even if the reaction chamber is completely shut off, the control body 16 is provided with a through hole 161 for passing the processing gas. Therefore, it does not hinder the heat treatment.

Further, even when the control body 16 is made to function as a buffer plate, there is no ring-shaped gap between the inner wall of the furnace core tube 1 and the buffer plate, and the permeation control of the processing gas is performed by drilling a cylindrical body. Since only the holes 161 can be used, highly accurate and reliable ventilation control is possible, and stable product quality and high quality are achieved.

In addition, the control body 16 is provided with a heat treatment area A and a combustion section (tail tube) 14
Each of them may be configured to be separable, and the control body
16 and the heat treatment area A may be integrated with each other so as to be separable from the combustion section (tail tube) 14, and the combustion section 14 and the control body 16 may be integrated with each other to form the heat treatment area A. It may be configured such that it can be divided on the 11-12 side.

Therefore, when the control body 16 is configured to be divisible into the heat treatment area A and the combustion section (tail tube) 14, or when the control body 16 and the heat treatment area A are integrated, a CV
In the apparatus D, the oxide film adhered to the inner wall surface side of the furnace core tube 1 was larger on the tail tubes 13 and 14 side of the furnace core tube 1 having the temperature gradient than in the heat treatment area A storing the wafer 3. It is easy to occur. Therefore, it is preferable that at least the tail tube peripheral portion 13 outside the heat treatment area A is configured to be dividable so that the tail tube peripheral portion 13 can be frequently washed and replaced.

Even when the heat treatment area A is heated to a temperature of 900 to 1200 ° C, the connecting portions 21 to 28 of the pipes are connected to the control body 16
Since it was formed in the area deviated from the heat treatment area A through
It is possible to accurately divide and re-assemble the connected fitting end without thermal deformation, which makes it possible to maintain stable sealing performance over a long period of time and greatly improve durability.

Further, the connecting portions 21 to 28 of the divided bodies 11 to 16 are arranged in the heat treatment area A.
Being formed in the area deviated from the above, for example, by setting the connecting portions 21 to 28 at a position such that the atmospheric temperature is equal to or lower than the heat resistant temperature of the heat resistant seal member, together with preventing thermal deformation of the connecting end. It is possible to significantly improve the sealing performance, and it can be effectively applied to a device using so-called toxicity, flammability and other dangerous gases.

Further, in the furnace core tube structure applied to the wet oxidizer, since the tip of the pile tube 142 is directed to the furnace core tube end surface 14a side, the furnace core tube end surface 14a is generated by the oxyhydrogen flame from the pile tube 142. And the holes are opened, and as a result, the wear of the combustion portion 14 is remarkable with respect to the furnace core tube body 11-12 side.

Therefore, in the main body, the entire furnace core tube was replaced even when only the combustion section 14 was worn.
Since the heat treatment area A and the combustion section (tail tube) 14 are configured to be divisible or integrated with the control body 16 and the heat treatment area A, only the combustion section 14 needs to be replaced. The cost is greatly reduced.

It should be noted that a tube body of the combustion section 14 and the tail tube peripheral portion 13 is prepared, and the tube bodies 13 and 14 are appropriately selected and used, so that one furnace core tube 1 can be used as a CVD apparatus. It can be applied as a wet oxidizer and is extremely convenient in practice. preferable.

[Embodiment] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but merely illustrative examples. Nothing more than.

1 and 2 show a furnace core tube structure to which the present invention is applied, which particularly functions as a CVD apparatus, in which a long cylindrical tube 11 extending in a horizontal direction and a silicon O-ring 4 are interposed. It comprises a tail pipe peripheral portion 13 fitted and connected to one end side of the cylindrical pipe 11 and a flange portion 12 fitted and fixed to the other end opening of the cylindrical pipe 11.

The cylindrical tube 11 has an axial length larger than that of the heat treatment area A in which the heating element 2 is surrounded, and one end side thereof is slightly reduced in diameter to a taper 21 shape, and a part of the taper surface is formed into a ring shape 21a. The O-ring 4 is formed so as to be recessed so that the other end side opening is formed by engraving a screw thread 22 on the outer peripheral end and connecting the gas introduction pipe 5 on the peripheral surface in the vicinity thereof. It

The tail tube surrounding portion 13 connects the tail tube 13a that functions as a gas exhaust tube to the tip end of the cylindrical dome shape as is known,
The inner peripheral side of the opening end is slightly expanded in the shape of a taper 24 so that it can be fitted into the taper 21 of the cylindrical tube 11.

The flange portion 12 has a disc ring shape, and a screw thread 23 is engraved on the inner peripheral side thereof.

According to such a furnace core tube structure, a predetermined furnace core tube 1 can be formed by screwing the flange portion 12 into the screw thread 22 on the other end side, and as shown in FIG. Is used by penetrating inside the heating element 2. At this time, since the cylindrical tube 11 is formed with an axial length larger than that of the heat treatment area A in which the heating element 2 is surrounded, both ends thereof are formed. Side mating part
It is possible to directly fit and fix the taper 21 of the cylindrical tube 11 to the taper 24 of the tail tube peripheral portion 13 through the O-ring 4 without exposing the taper 21-24 and 22-23 to a high temperature, but it is more preferable. The present invention can be easily realized by interposing the control body 16 shown in FIG. 5 between the cylindrical pipe 11 and the tail pipe peripheral portion 13, and at the same time, the flange portion 12 which is easily damaged and the oxidation. Since a large amount of the film adheres, it becomes possible to easily remove or replace the tail tube peripheral portion 13 which is frequently washed.

Further, by attaching a cylindrical combustion section 14 to the cylindrical tube 11 as shown in FIG. 3, it can be used as a hydrogen combustion type wet oxidation furnace. That is, the figure shows the O ₂ supply pipe 141 and the H ₂
A pile tube 142 for supplying the above is shown, and a combustion section 14 having the same taper 25 shape as that of the above embodiment is shown on the opening side. By attaching the combustion section 14 to the cylindrical tube 11, the pile tube H ₂ introduced from 142 and supply pipe 141
Also, the steam gas can be generated in the furnace core tube 1 by igniting the O ₂ gas using the temperature in the furnace.
In the case of this embodiment, the taper of the cylindrical pipe 11 is caused due to a thermal problem.
The O-ring 4 is not interposed between the taper 21 'and the taper 24' of the combustion section 14 and is directly sealed.

In this case as well, the present invention can be easily realized by interposing a cylindrical control body 16 between the combustion section 14 and the cylindrical tube 11.

That is, the structure thereof will be described based on FIGS. 4 and 5, and the furnace core tube structure of the present embodiment is applied as a wet combustion furnace of a hydrogen combustion system.

That is, the present embodiment has an opening for loading and unloading the boat 6 in which the wafers 3 are aligned on the taper 26 side, and has the other end on the heating element 2 side.
The cylindrical control functioning as a buffer plate between the cylindrical tube 15 formed by extending further from the heat treatment area A surrounded by and the combustion section 142 to which the pile tube 142 shown in FIG. 3 is attached. A furnace core tube 1 structure in which a body 16 is interposed is formed.

The inner peripheral side of the end of the cylindrical tube 15 used in the present embodiment is slightly expanded in the shape of a taper 28 through the O-ring 4, and the open end side of the combustion section 142 is slightly tapered on the inner peripheral side. The diameter is expanded in a 24 'shape so that it can be directly fitted to the outer peripheral ends 26, 27 of the cylindrical control body 16.

As shown in FIG. 5, the control body 16 has a hollow cylindrical shape made of quartz glass and is formed with an outer peripheral wall 162 having the same outer diameter 151 as the furnace core tube 1.
In addition to having a heat insulating structure filled with 163, a large number of through holes are formed in the control body 16 in the axial direction by using a quartz pipe.
161 is provided so that the steam gas generated on the side of the combustion section 14 to which the pile pipe 142 is attached can uniformly flow into the heating region at a controlled flow velocity.

In addition, the peripheral surfaces on both sides of the control body 16 are slightly reduced in diameter to taper 26, 27, and a part of the one taper surface 26 is ring-shaped.
The O-ring 4 is formed so as to be recessed in the shape of 26a so that it can be interposed.

According to this furnace core tube 1 structure, the taper 24'-27, 26- is provided between the cylindrical tube 15 and the combustion section 142 to which the pile tube is attached.
By using the 28 to sequentially fit the control body 16 and the combustion part 14, the airtight furnace core tube 1 with the sealing property of the O-ring 4
Can be formed, and the action of the present invention can be achieved smoothly.

[Advantages of the Invention] As described above, according to the present invention, many operations are performed on the outer periphery of the control body while eliminating the loading / unloading operation of the control body such as the buffer plate or the heat insulating cylinder for controlling the reaction atmosphere in the core tube. It is possible to completely eliminate the basic drawback that the void space is formed, and facilitate the cleaning of the core tube, the control body, and the like.

It has various remarkable effects.

The present invention is not limited to the horizontal type processing device, and can be easily applied to the vertical type processing device.

[Brief description of drawings]

1 and 2 show a core tube structure to which the present invention is applied, particularly as a CVD apparatus. FIG. 1 is an exploded view thereof, and FIG. 2 is an assembly view thereof. FIG. 3 shows a core tube structure to which the present invention is applied, particularly as a wet oxidizer. FIG. 4 shows an embodiment of the present invention constructed using FIG.
FIG. 4 is a schematic view of the apparatus, and FIG. 5 is a partially cutaway perspective view showing a control body incorporated in the core tube. 3: Semiconductor wafer A: Heat treatment area 1: Furnace core tube 16: Control body 151: Furnace core tube outer peripheral wall 14: Combustion section with pile tube 142 attached 13: Tail tube peripheral section

Claims (5)

[Scope of utility model registration request] 1. A furnace core tube structure for performing heat treatment on a wafer while flowing a processing gas in a heat treatment area containing a semiconductor wafer, and an atmosphere control functioning as a buffer plate or a heat retaining tube for controlling an atmosphere in the furnace core tube. Reactor core tube structure, characterized in that the body is formed of a cylindrical body having one or a plurality of through holes, and the outer peripheral wall of the control body constitutes part of the outer peripheral wall of the furnace core tube. 2. The furnace core tube structure according to claim 1), wherein the control body is separably fitted in the furnace core tube. 3. When the furnace core tube according to claim 1 is applied to a wet oxidizer, the control body is interposed between a combustion section to which a pile tube is attached and the heat treatment area. The furnace core tube structure according to claim 1) 4. When the furnace core tube according to claim 1 is applied to a CVD apparatus, the control body is interposed between a heat treatment area and a tail tube peripheral portion located in an area outside the heat treatment area. A furnace core tube structure according to claim 1, characterized in that 5. The furnace core tube structure according to claim 1, wherein the control body is formed of a heat insulating structure.