JPS62128524A - Vertical type semiconductor thermal treatment equipment with reaction tube having multiple structure - Google Patents

Abstract

PURPOSE:To provide the inflow of the outside air in a carry-in-out process by mounting a detachable external reaction tube and an internal reaction tube carried into and carried out of the external reaction tube together with a wafer boat to a furnace body and supplying the internal reaction tube with an inert gas. CONSTITUTION:An outlflow hole 45 is closed, and an internal reaction tube 18 is supplied with an inert gas. Air in the internal reaction tube 18 is pushed out to the outside from a lower-end opening 19 by the difference of specific gravity with the supply of the gas, and wafers 20 in the internal reaction tube are isolated from air at the time when the gas is filled. The gas is supplied again during lowering into an external reaction tube 16 together with a wafer boat 22 of the internal reaction tube 18 filled with the gas, and the excessively fed gas flows out into the external reaction tube from the lower-end opening 19 for the internal reaction tube. The gas flowing out to the outside from an upper-end opening 15 forms a kind of a gas shower, and prevents the inflow of air to the external reaction tube 16.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention has a multi-layer structure for reaction tubes, and the internal reaction tube, which moves together with the plate loading means, is filled with an inert gas to allow outside air to flow in. The present invention relates to a vertical type 1'-conductor heat treatment apparatus that prevents.

[Prior art]

゛The conductor No. 1 (plate, for example, a silicon wafer (hereinafter referred to as wafer) is
They are stacked in stages and transported into a reaction tube of a vertical semiconductor heat treatment apparatus. Reaction residues such as oxygen gas and hydrogen gas are then supplied into the I5 tube heated to about 1200'C, and the wafer is subjected to predetermined heat treatments (including chemical treatments) such as oxidation, diffusion, and CvD. The purity of the reaction gas supplied into the reaction tube greatly influences the result of the heat treatment. In order to prevent non-uniformity in film thickness and film quality, poor conductivity, etc., and to ensure a high yield, extremely high-purity anti-J5 gas is supplied into the reaction tube.

The main parts of vertical semiconductor heat treatment equipment are usually located in a clean room, and air purified by high-performance filters is supplied to the clean room. However, it is extremely difficult to completely eliminate impurities such as dust and moisture from the air.

Therefore, impurities are contained in the air inside the clean room, albeit in small quantities.

Incidentally, the wafers are stacked on wafer ports with vertical separation and heated to 800°C before and after the heat treatment process.
The sample is transported into or removed from a reaction tube whose temperature has been lowered to a certain degree. The reaction tube has its north end or lower end open, and its opening is usually closed with a cover called a barrier. For example, if the E end of the reaction tube is open, it can be used for loading wafers.

After the barrier is removed to open the top opening of the reaction tube, the wafer port is lowered into the reaction tube. and,
The top opening is closed by a cover that descends with the wafer port. After a predetermined heat treatment is performed, when the wafer port is raised to carry out the wafer, the cover is raised together with the wafer port, and the upper end opening is opened. After the wafer port is removed from the reaction tube, the reaction tube is closed by a barrier. after that.

For the next heat treatment, the wafer port loaded with wafers is transported above the reaction tube, and the reaction tube is closed until the loading of one reaction tube is resumed.

However, due to the loading ratio of wafers, when the upper end opening or the lower end opening of the reaction tube is opened, room temperature air from the clean room instantly flows into one reaction tube through the opening. Furthermore, when carrying in wafers, air from the clean room is interposed between the wafers in the wafer port and flows into the reaction tube together with the wafers.

The heat treatment is performed by heating one reaction tube to about 1200° C. by energizing a heating coil disposed around the reaction tube. After the heat treatment, the power supply to the heating coil is stopped, the temperature of the reaction tube is lowered to about 800° C., and the wafer loading ratio is performed. Therefore, the air (outside air) that has flowed in is heated by the residual heat of one reaction tube.

When loading and unloading wafers, the wafers are transported between the room-temperature outside air of the clean room and the high-temperature reaction tube. and,
To prevent wafers from cracking or becoming distorted due to rapid heating or cooling, the wafer ports should be
It is raised and lowered at a low speed of m/win. However, as mentioned above, since the outside air flows into the reaction tube and is heated, the heated outside air causes a chemical reaction on the wafer during the loading process, and an oxide film etc. are formed on the wafer 1. The disadvantages have long been pointed out. The inflow of outside air when the wafers are being carried in, particularly when they are being carried in, reduces the yield. That is, if an oxide film is formed on the wafer E before the heat treatment, a predetermined oxide film is formed on the unnecessary ridges of the oxide film during the heat treatment. Therefore, after the heat treatment, the unnecessary oxide film cannot be removed from inside the predetermined oxide film, and the wafer has no choice but to be disposed of as a defective product.

In addition 5. , l: As mentioned above, the air in a clean room is contaminated by impurities such as dust and moisture, albeit slightly. Therefore, the outside air flowing into the reaction tube not only forms an unnecessary oxide film, but also contaminates the high-purity reaction gas supplied to the reaction tube, causing uneven film thickness, poor conductivity, etc., and reducing the yield. causing a decline.

In addition, recently, attention has been paid to the adverse effects of chemical reactions caused by air at approximately room temperature in clean rooms. It has been pointed out that when the wafer port is transported through a clean room to enter the mountain, unnecessary oxide films and the like are formed on the wafer due to chemical reactions with impurities in the air.

For example, before the wafer is set in a wafer cassette, the wafer is exposed to air in a clean room, and chemically reacts with impurities in the air to form unnecessary oxidized nQ and the like on the wafer. For this reason, conventionally, the surface of the wafer is polished to remove oxide films and the like before transferring the wafer.

However, in the loading transfer step, the wafer /\ is transferred from the wafer cassette to the wafer port by the wafer transfer means, and then the wafer port is transferred into the reaction tube. Moreover, the transfer process for carrying out is performed by following the reverse procedure. here.

The wafer transfer means is disposed adjacent to the vertical semiconductor heat processing apparatus, and each transfer step is performed quickly.

However, the reaction tubes were lowered due to the loading and unloading of wafers.
The wafers are transported in and out of the reaction tube, which has a diameter of approximately 800'. In order to prevent thermal strain from occurring in the wafer due to sudden temperature changes, the wafer port is designed to have a 50 to 100 ff1l/
The robot is raised and lowered at a slow speed of 20 seconds, and it takes about 20 minutes to go up and down. In addition to being transferred from the wafer cassette to the wafer hoard, the wafers are transferred from this stage 1. Even during descent, they are exposed to air at approximately room temperature in the clean room. Therefore, an undesirable oxide film or the like is formed on the wafer due to a chemical reaction with impurities in the air, such as 01, H, and O.

In order to prevent the inflow of outside air when wafers are being carried in, a method of preventing outside air inflow using a gas shower is widely adopted. A method of preventing inflow of outside air using a gas shower was developed for horizontal conductor heat treatment equipment in which reaction tubes are arranged almost horizontally, and has been applied to vertical semiconductor heat treatment equipment.

In a method for preventing outside air inflow using a gas shower, for example, a scavenger box is placed adjacent to the opening of the reaction tube, and a gas shower is provided within the scavenger box. That is, high pressure inert gas is introduced into the scavenger box and directed onto the wafer to form a gas shower. Then, after the outside air interposed between the wafers on the wafer port is sucked into the exhaust pipe together with an inert gas and removed, the wafer is carried into the reaction tube. Such a gas shower not only prevents outside air from flowing in between the wafers, but also prevents outside air from flowing in when openings are opened when loading and unloading wafers.

[Problems with conventional technology]

However, although the known method of preventing the inflow of outside air using a gas shower prevents the inflow of outside air to some extent, it is not necessarily sufficient. This is considered to be due to the following reasons.

Even when loading and unloading wafers, the internal temperature of the reaction tube remains at 8.
Since the temperature is close to 00° C., the high temperature reaction gas tends to flow out from the open opening of the reaction tube. While the reactive gas is at a high temperature, the inert gas is supplied at room temperature, so there is a large temperature difference between the reactive gas and the inert gas. Therefore, the large temperature difference becomes a hindrance, and the inert gas does not mix smoothly with the reaction gas near the opening of the reaction tube, creating a vortex and creating a local negative pressure. In particular, from a microscopic perspective, the reaction gas does not flow uniformly in the reaction tube, and a relatively large negative pressure is generated. The gas shower flows across the flow of outside air that is about to flow in, and because the cross-sectional area of the opening is large, the suction force due to negative pressure locally overcomes the gas shower, forcing the outside air into the reaction tube. tend to lead. Therefore, it is difficult to prevent outside air from flowing upward.

Furthermore, the prior art does not provide an effective means for preventing chemical reactions caused by the air at approximately room temperature in the clean room during the transport process of carrying in and out of the clean room.

[Purpose of the invention]

The object of the present invention is to provide a vertical semiconductor heat treatment apparatus that prevents the inflow of outside air during the 1112-person production process and prevents chemical reactions caused by room temperature air during the transport process.

[Summary of departure in January] To achieve this objective, according to the invention.

The reaction tube has a multilayer structure. In other words, the reaction tube consists of an outer reaction tube that is removably supported by the furnace body and extends almost vertically, and an inner reaction tube that houses a semiconductor substrate loading means, such as a wafer port, and is carried into the outer reaction tube together with the wafer port. It is equipped with Further, an inert gas supply means is arranged to supply an inert gas to the internal reaction tube.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

As shown in FIG. The reaction tube 14 has a double structure including an outer reaction tube L6 that is detachably supported by the furnace body 12 and extends almost vertically, and an inner reaction tube L6 that is carried into the outer reaction tube. ing. The wafer port 22 loaded with wafers 20 is housed in the internal reaction tube 18 and transported together with the internal reaction tube. The reaction tube 14 is not limited to a double structure; for example, an outer reaction tube 1B, an inner reaction tube 1
Either or both of 8 may be made into a double structure to give the reaction tube a triple or more multilayer structure. In the embodiment, the reaction tube 14 is formed into a so-called L-condensation rotary tube with an open upper end. However, it is also possible to form a rotary tube with an open end.

As can be clearly seen from FIG. 2, the vertical conductor heat treatment apparatus 10 is equipped with an inert gas supply stage 24 for supplying an inert gas to the internal reaction tube 18. The inert gas to be supplied is selected so that it remains in the internal reaction tube 18 and easily fills it due to its specific gravity difference with air. For example, in the embodiment, the reaction tube 14 is rotatable from top to bottom, the outer reaction tube 16 is open at the top, and the inner reaction tube 18 is open at the bottom. Therefore, in the embodiment, helium gas, which has a smaller specific gravity than air, is used as the inert gas.

Nitrogen gas, neon gas, etc. may be used instead of helium gas. Also, in a reaction tube with a rotary tube between the bottom ends, argon gas, krypton gas, or xenon gas, which has a higher specific gravity than air, is used as an inert gas in the internal reaction tube. Needless to say, it is supplied, and furthermore, in the rotaib between the lower ends,
Helium gas, which may be filled by constantly supplying inexpensive nitrogen gas without considering the difference in specific gravity, is controlled by a control valve 28 and flows through the conduit 2 and the flow path 3 formed in the rod 30.
2 to the internal reaction tube 18. Note that the rod 30 is fixed to the base 33 of the internal reaction tube 18. A coupling 27 is also attached to the rod 30 and an annular groove 29 is formed in the inner wall of the coupling. The flow path 32 is communicated with the conduit 2 via the annular groove 29. In such a configuration, the internal reaction tube 1
8 is rotated during the 8 process, communication between the conduit 28 and the flow path 32 is ensured.

As shown in FIGS. 1 and 3, the wafer port 22
A flange (outer flange) 34 is fixed to the upper end of the rod 31 and extends radially outward. A plurality of locking pieces 3B, four in the embodiment, extend equiangularly from the outer flange 34. Here, the outer flange 34 may be omitted and the piece 3B may be directly passed through the rod 3I. A wafer port body 38 is fixed to the lower end of the rod 31, and the wafer port body has a number of vertically equally spaced shelves, and the wafers 20 are supported on the shelves.

Further, the internal reaction tube 18 has a flange (inner flange) 42 extending radially inward. And, staff LE
A cut-out 44, which can be cut over three days per side, is formed in the inner flange 42.

After the wafer 20 is transferred from the wafer cassette (not shown) to the wafer port 22 by the wafer transfer device 7t (not shown), the wafer port is stored in the internal reaction tube 18 as follows.

First, cut out the notch 4 of the internal reaction tube 1B suspended in a predetermined position.
4, the locking pieces 3G of the wafer port 22 are aligned.

Then, the wafer port 22 is raised 1 and the locking piece 3
After B passes through the notch 44, the wafer port 22
For example, when viewed from -H, it is rotated 45 degrees clockwise and lowered. Then, the locking piece 38 is locked to the inner flange 42, and the wafer port is accommodated within the internal reaction tube 18. Here, instead of raising and rotating the wafer port 22, the internal reaction tube 1B may be lowered and rotated.
The configuration in which the wafer port 22 is engaged with and accommodated in the internal reaction tube 18 is not limited to the combination of the engagement 1F piece 36 and the inner flange 42. It is preferable to provide means for preventing the wafer port 22 from falling off while the internal reaction tube 18 is rotating. The drop-off prevention means is configured to include, for example, engageable concavo-convex portions, with four portions provided on the lower surface of the locking piece and a convex portion provided on the upper surface of the inner flange 42, respectively. According to such fall prevention means, the wafer port 22 is connected to the internal reaction tube 1.
8, and is fully prevented from falling off.

Outflow holes 45 for the reaction gas are formed in the base 33 of the internal reaction tube 33. The outflow hole 45 is normally closed by a reaction tube cover 46 placed on the base 33 and raised and lowered together with the internal reaction tube 18 . Then, as will be described later, when the inner reaction tube 18 is lowered and the cover 46 is supported by the support flange 47 of the outer reaction tube and separated from the base 33, the outflow hole 45 is opened.

The wafer port 22 is housed in the internal reaction tube 18, and the cover 46 is placed on the base 33 of the internal reaction tube 18 to open the outflow hole 4.
After closing 5, the inert scum supply and feed f stage 24 are activated,
Helium gas is supplied to the internal reaction tube 18.

The helium gas is supplied to the internal reaction 'i? 13. Here, the north end of the internal reaction tube 18 is closed by the base 33, and the outflow hole 45 bored in the base is closed with the cover 46, so that the helium gas does not flow out from the upper end of the internal reaction tube. Helium gas has a lower specific gravity than air, so
Only after the inner reaction tube has been filled can it flow out from the end opening 19 of the inner reaction tube.On the other hand, the air in the inner reaction tube 18 is forced downwardly from the ratio difference as helium gas is supplied. and is pushed out from the lower end opening 19.

Then, at the time when the internal reaction tube 18 is filled with helium gas.

There is no room for air to remain in the inner reaction tube, and the wafers 20 within the inner reaction tube are isolated from the air.

Therefore, before the wafer 20 is carried into the external reaction tube I6, no chemical reaction occurs on the wafer caused by the air at approximately room temperature in the clean room, and air is interposed between the wafer and the external reaction tube I6. There is no possibility that it will flow into

Once the internal reaction tube 18 is filled with helium gas, the control valve 28 is temporarily closed. Then, the inner reaction tube 18 filled with helium gas is transported inside the clean room together with the wafer port 22, and the outer reaction tube 18 is transferred to the wafer port 22.
and gradually lowered into the outer reaction tube. During descent, control valve 2B is opened and helium gas is supplied again. The control valve 26 may be continuously opened without being closed once, and the excessively supplied helium gas flows out from the lower end opening 18 of the inner reaction tube to the outer reaction tube 16 during the descent of the inner reaction tube 18. . And helium gas is the first
As shown by the arrow in the figure, it rises through the gap between the reaction tubes 18.18, flows out from the upper end opening 15 of the outer reaction tube 16, and flows into the furnace body
into a scavenger box (not shown) located above 2. The helium gas flowing out from the top opening 15 forms a kind of gas shower at the top opening. The gas shower made of helium gas flows against the flow of outside air. Therefore, the flow of helium gas generates a large resistance force against the flow of outside air. In addition, the upper end opening 15 is closed by the internal reaction tube 18, leaving only a small annular space between the reaction tubes 18 and 18, and the flow path through which the outside air is to enter is in this small annular space. Only. In this way, in addition to a large resistance force acting against the flow of outside air, 1
1if, because the path is narrow, in the loading process of wafer 2o,
The inflow of air into the external reaction tube 16 is prevented for -1 minutes.

After the helium gas flows through the channel 32, it is immediately discharged into the internal reaction tube 18 directly from the base plate 33.

However, after heating using the residual heat of the external reaction tube IB,
Preferably, a conduit 35 for discharging helium gas is provided in the inner reaction tube, for example, as shown in FIG. Preferably, this conduit 35 is connected to the channel 32 at one end and opened directly below the base 33 at the other end. In such a configuration, from the flow path 32 to the conduit 3
When the helium gas flowing into the tube 5 flows through the conduit, it is heated by residual heat from the external reaction tube 1B. When helium gas is heated and expanded, its resistance against the inflow of outside air increases, and the inflow of outside air is further prevented. if,
If the helium gas flows out from the lower end opening 19 before the internal reaction tube 18 is filled, negative pressure may be generated in the internal reaction tube, leading to the inflow of outside air. However, the heated and lightened helium gas does not flow out from the lower end opening 18 until after it is filled, so there is no room for negative pressure to occur and the inflow of outside air is sufficiently prevented. Note that if the conduit 35 is arranged in a meandering manner within the internal reaction tube 18, the heating time will be increased and the helium gas will be effectively heated. In particular, conduit 3
It is better to make the lower end of 5 meander. Furthermore, it is sufficient that the conduit 35 is disposed along the wall surface, and may be disposed along the outer wall instead of the inner wall.

Even after the cover 46 is supported by the support flange 47 of the outer reaction tube, the inner reaction tube 18 continues to descend to a predetermined position. Here, the reaction tube 14 is closed as the cover 4B is supported by the support flange 47, and then the outflow hole 45 is opened as the internal reaction 'f1B further descends. After the internal reaction tube 1B has been lowered to a predetermined position, the scavenger box opening [1] is closed and the furnace body 12 is closed.
The barrier is returned to its initial position to close the wafer, completing loading of the wafer.

Then, a predetermined reactant gas, for example, water vapor, is supplied from the reactant gas introduction section 4B provided at the lower end of the external reaction tube 1B, and the wafer 20 is subjected to a predetermined heat treatment.

The water vapor rises within the internal reaction tube 18 and is discharged to the outside of the reaction tube 14 through the outflow hole 45 . During the heat treatment process,
The control valve 2B is closed and the helium gas in the internal reaction tube is discharged together with the reaction gas at the initial stage of the 8 processing steps.

Channel 32 is not utilized during the heat treatment process, so
The outflow hole 45 may be removed and the flow path 32 may be configured to also serve as a reaction gas discharge path. For example, if the conduit 28 is provided with a switching valve and the reaction gas discharge conduit is connected to the switching valve. , the flow path 32 can also serve as a reaction gas discharge path.

In addition, as shown in FIG.
Before the inner reaction tube 18 is lowered into position, the cover 148 is supported on the support flange 47 and separated from the inner reaction tube. Therefore, even if the internal reaction tube 18 rotates during the heat treatment process, there is no risk that the conduit 28 will wind around the rod 30.

In the configuration in which the cover 146 is provided with the channel 132, it is necessary to align the outflow hole 45 and the channel 132 in the wafer unloading process. However, by controlling the daily rotation of the internal reaction tube using a sensor or the like, the internal reaction tube is accurately stopped at a position where the outflow hole 45 is aligned with the flow path 132.

After the heat treatment process is completed, the internal reaction tube 18 is raised and the control valve 26 is opened. Immediately after the internal reaction tube 1B begins to rise, the outflow hole 45 is closed again by the cover 46. Therefore, the internal reaction tube 18 is filled with helium gas, and the excess helium gas flows out from the lower end opening 18 and rises through the gap between the reaction tubes 16 and 18, forming a gas shower in the opening 15. Therefore, as in the import process,
Even in the process of carrying out the wafers 20, outside air does not flow into the external reaction tube te, and the inside of the external reaction tube is not contaminated.Furthermore, helium gas does not flow into the internal reaction tube! 8, and the wafer 20 is transported isolated from the outside air. Therefore, no unnecessary chemical reactions occur on the wafers after heat treatment during the transport process. Furthermore, even during the transport process, the helium gas supplied to the internal reaction tube 18 is heated by the residual heat of the external reaction tube 16. As mentioned in the carrying-in process, no negative pressure is generated in the internal reaction tube, so that the inflow of outside air into the internal reaction tube 18 is sufficiently prevented.

After the wafer 20 is unloaded and while another wafer is loaded, an inert gas can be supplied from the reaction gas inlet 48 to the external reaction tube 16 to prevent outside air from flowing into the external reaction tube 16. Preferably, an inert gas may be supplementarily supplied to the external reaction IrF 1111 from the reaction gas introduction part 48 while the internal reaction tube 18 is being raised and lowered for loading and unloading the wafer 20. The supplementary supply intensifies the gas shower at the top opening 15 and further prevents the inflow of outside air. Needless to say, the same inert gas is used to avoid mixing of inert gases.

The inert gas supplied from the reaction gas introduction part 48 to the external reaction tube is heated by the residual heat of the external reaction tube. Therefore, if the inert gas supplied to the internal reaction tube is at room temperature, there will be a large difference in specific gravity between it and the inert gas in the external reaction tube. Active gas falls rapidly. This may generate negative pressure in the internal reaction tube, leading to the inflow of outside air. However, as described above, in the configuration in which the conduit 35 is arranged in the internal reaction v18 to heat the inert gas to the internal reaction tube, the generation of negative pressure due to the difference in specific gravity is prevented, and the inflow of outside air is prevented. .

Note that reference numerals 50, 52, and 54 indicate a heat insulating material, a heating coil, and a soaking tube, respectively.

〔Effect of the invention〕

As described above, according to the present invention, an inert gas is supplied and filled into the inner reaction tube during the transfer process of loading and unloading semiconductor substrates, such as wafers, into and out of the outer reaction tube. Therefore, the wafers in the semiconductor cultivation area/shallow area such as the wafer port in the internal reaction tube are isolated from the clean room air (outside air), and there is no risk of chemical reactions occurring on the wafers during the transfer process.

Furthermore, since the wafer is filled with inert gas, air is removed from between the wafers on the wafer port, and air is prevented from flowing into the (external) reaction tube when the wafer is carried into the wafer port.

Furthermore, if an excessive amount of inert gas is supplied to the internal reaction tube so that a part of it flows out from the internal reaction tube during the loading/unloading process, the inert gas will fill the gap between the internal reaction tube and the external reaction tube. and exits from the open end of the outer reaction tube. Therefore,
A kind of gas shower is formed at the open end of 1 reaction e by the inert gas flowing out. And this gas shower does not cross the flow of outside air that is about to flow in,
It flows against the flow. Therefore, the flow of inert gas generates a large resistance force against the flow of outside air. In addition, the open end of the outer reaction tube is closed by the inner reaction tube, leaving only a small annular space between the inner reaction tube and the outer reaction tube, and the flow path into which the outside air is to enter is This small annular space exerts a large resistance to the flow of outside air, and in addition, the narrow flow path prevents outside air from flowing into the (external) reaction tube during the WI extraction process. The inflow of is sufficiently prevented.

As described above, according to the present invention, unnecessary chemical reactions caused by exposure of the wafer to normal temperature air in a clean room are prevented, and outside air is prevented from flowing into the (external) reaction tube.

The above-mentioned embodiments are for illustrating the present invention, and are not intended to limit the present invention in any way, and any modifications, modifications, etc. made within the technical scope of the present invention are also included in the present invention. Needless to say, for example, a vertical semiconductor heat treatment apparatus equipped with a reaction tube with a rotary tube between upper ends has been described in the embodiment, but the present invention is applicable to a vertical semiconductor heat treatment apparatus equipped with a reaction tube with a rotary tube between lower ends. It will be obvious that the term also includes devices.

[Brief explanation of drawings]

:Pj1 is a schematic longitudinal sectional view of a vertical semiconductor heat treatment apparatus according to the present invention. Figure 3 is a cross-sectional view of the internal reaction tube taken along the line [-117 in Figure 1. Figure 1 is a schematic diagram of the internal reaction tube. A perspective view, FIG. 5 is a partial vertical sectional view of a modified internal reaction tube. 10: vertical semiconductor heat treatment equipment, 12: furnace body, 14: reaction tube, 15: upper end opening of external reaction tube, 18: external reaction tube,
18: Internal reaction tube, 18: Lower end opening of internal reaction tube. 20: Wafer (semiconductor substrate), 22: Wafer port ('F-conductor substrate loading means), 24: Inert gas supply stage, 26: Control valve, 32.132: Flow path, 33: Internal reaction tube 7! i board, 34: outer flange of wafer port, 35: inert gas heating conduit, 36: locking piece of outer flange, 42: inner flange of internal reaction tube, 44: notch of inner flange, 45: Outflow hole for reaction gas, 46:
Reaction tube cover. Figure 1 Figure 2 Figure 3

Claims (5)

[Claims] (1) A reaction system with a multiplex structure comprising an external reaction tube that is removably supported by the furnace body and extends almost vertically, and an internal reaction tube that houses a loading means for semiconductor substrates and is carried in and out of the external reaction tube together with the loading means. A vertical semiconductor heat treatment apparatus comprising a tube and an inert gas supply means for supplying an inert gas to an internal reaction tube. (2) the loading means includes a plurality of locking pieces extending radially outward, the internal reaction tube has a corresponding inner flange capable of locking the locking pieces; 2. The vertical semiconductor heat treatment apparatus according to claim 1, wherein the inner flange has a notch through which it can pass. (3) A conduit for the inert gas is disposed within the inner reaction tube, and the inert gas is heated by the residual heat of the outer reaction tube while flowing through the conduit. vertical semiconductor heat treatment equipment. (4) The internal reaction tube has one end closed by the base and the other end open, and the conduit extends along the wall of the internal reaction tube to near the open end of the internal reaction tube, and then returns to near the base. 4. The vertical semiconductor heat processing apparatus according to claim 3, wherein the open end of the conduit is located adjacent to the base of the internal reaction tube. (5) The vertical semiconductor heat treatment apparatus according to claim 1, wherein the conduit is arranged in a meandering manner.