JPH0221616A - Heat treatment equipment for semiconductor device - Google Patents

Abstract

PURPOSE:To completely burn unfurnt surfactance in flue gas, unnecessitate the dilution by inert gas as a counter-measure for explosion, and improve the maintainance efficiency, by installing a flue gas treatment chamber to mix the flue gas generated in a main reaction pipe with oxygen gas, in the midway of an exhaust channel, and burn the glue gas. CONSTITUTION:In an electric furnace 2, the end of a main reaction pipe 1 is connected with a flue gas treatment equipment, via a flue gas treatment furnace 9. From a feeding pipe 3, reducing gas such as hydrogen gas is supplied, and flue gas generated in a main reaction chamber, in the main reaction pipe 1, in which a sample is inserted is sent to the flue gas treatment furnace 9. This flue gas is mixed, in the vicinity of an inlet 13, with oxygen gas from piping 14, and burned by the heating of an electric furnace 10. Since the combustion is performed in a closed reaction pipe 11, the safe working is enabled, even if reactive substance is contained in the flue gas.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heat treatment apparatus for semiconductor devices for performing heat treatments such as oxidation, diffusion, annealing, and deposition.

[Prior Art] The configuration of a conventional heat treatment apparatus for semiconductor devices will be described with reference to FIGS. 9 and 10. First, to describe the structure of the apparatus shown in Fig. 9, numeral 1 is a main reaction tube made of a quartz tube, etc., and the main reaction chamber inside contains samples (not shown).
It is designed to accommodate. Reference numeral 2 denotes a heating furnace such as an electric furnace surrounding the main reaction tube 1. A supply pipe 3 for supplying a reaction gas such as hydrogen gas is connected to one end of the main reaction pipe 1, and the narrow end is sealed with an M5 provided with an exhaust pipe 4. Then, the exhaust gas generated in the main reaction chamber of the main reaction tube 1 is combusted by a pilot flame 6 provided at the outlet of the exhaust pipe 4 and released into the atmosphere.

The manufacturing apparatus shown in FIG. 10 has a different configuration for exhaust gas treatment from that shown in FIG. 9, in which a pipe 7 extending to an exhaust gas treatment apparatus (not shown) is connected to the terminal end of the main reaction tube 1.
The exhaust gas is sent to the exhaust gas treatment device along with an inert diluent gas such as nitrogen gas supplied via a separate pipe 8 connected midway through the pipe 7.

[Problems to be Solved by the Invention] However, such a heat treatment method has the following problems.

In the case of the apparatus shown in FIG. 9, if reactive substances or reaction products are contained in the exhaust gas, it becomes extremely dangerous for the operator. For example, vapor phase growth (VD),
When performing HCfJCf-ning or the like for cleaning the inside of the main reaction tube 1, it is extremely dangerous to apply the heat treatment apparatus shown in the figure.

In the case of Figure 10, the exhaust gas is treated in a sealed exhaust gas treatment device, so the dangers of the treatment shown in Figure 9 are eliminated, but in order to prevent explosions in the piping, It is necessary to dilute the exhaust gas with a large ω inert gas, which increases the processing cost, and also makes sealing the joint between the piping 7.8 and the main reaction tube 1 extremely complicated. There was a problem.

[Means for Solving the Problems] The present invention has been made in view of the above problems, and includes a heating furnace and a main reaction tube accommodated in the heating furnace, and includes a heating furnace and a main reaction tube accommodated in the heating furnace. In a semiconductor device heat treatment apparatus that heat-treats a sample placed in a gas atmosphere, a sealed exhaust gas treatment system is used in which the gas generated in the main reaction tube is mixed with oxygen gas and combusted in the middle of the exhaust path. ]! I! It is characterized by having a room. As a result, unburned substances in the exhaust gas can be completely combusted, eliminating the need for dilution with inert gas as an explosion-proof measure.Also, the structure is simple, making it easy to handle and improving maintenance efficiency. It is possible to achieve 4g of effects such as being able to improve the

[Example] Hereinafter, practical examples of the present invention will be explained with reference to the drawings.

In addition, the same reference numerals are given to the same or corresponding parts as in FIGS. 9 and 10.

First, the structure of the heat treatment apparatus according to the first embodiment will be described based on FIG. 1. 1 is a main reaction tube, 2 is an electric furnace,
The terminal end of the main reaction tube 1 is connected to an exhaust gas treatment device via an exhaust gas treatment furnace 9.

The exhaust gas treatment furnace 9 includes an electric furnace 10 and a reaction tube 11 made of a quartz tube or the like arranged in the center of the electric furnace 10. A plurality of baffle plates 12 that are substantially perpendicular to each other are provided, and a pipe 14 for supplying oxygen gas toward the vicinity of the exhaust gas inlet 13 is connected to form an exhaust gas treatment I'l+1. It is connected to an exhaust gas treatment device via an exhaust pipe 15 provided behind the baffle plate 12.

Next, to describe the operation of this device, a reducing gas such as hydrogen gas is supplied from the supply pipe 3, and the exhaust gas generated in the main reaction chamber in the main reaction tube 1 in which the sample is inserted is treated as exhaust gas. It is sent to furnace 9. This exhaust gas mixes with oxygen gas from the pipe 14 near the inlet 13 and is burned by heating in the electric furnace 10.

Since this combustion takes place inside the sealed reaction tube 11, the operation can be carried out safely even if the exhaust gas contains reactive substances. Note that it is preferable that the ratio H2102 (mole ratio) between the hydrogen gas M supplied to the main reaction tube 1 and the oxygen gas supplied via the pipe 14 (mole ratio) is 2 or less. Furthermore, when depository reactants are included in the exhaust gas due to a process such as CVD, the exhaust gas after the above combustion is further stirred by the baffle plate 12.
The reaction of unreacted substances is promoted, and a considerable amount of deposits can be removed by the baffle plate 11 before reaching the exhaust pipe 15, thereby reducing the burden on the exhaust gas treatment device.

According to this treatment method, there is no need to dilute the exhaust gas generated in the main reaction tube 1 with an inert gas from large seedlings and send it to the exhaust gas treatment device as in the conventional method, so that the treatment cost can be reduced. Furthermore, since the main reaction tube 1 and the reaction tube 11 are heated in separate electric furnaces 2 and 10, respectively, the temperature of the reaction tube 11 is set higher than that of the main reaction tube 1 to treat the exhaust gas. Independent heat treatment can be performed for each exhaust gas treatment ■! Unreacted gas can be efficiently reacted in the furnace 9. Furthermore, the exhaust gas treatment furnace 9 has a simple structure and can be easily removed from the main reaction tube 1, so deposits accumulated on the baffle plate 12y can be easily cleaned, resulting in extremely high maintenance efficiency. .

Next, a second embodiment will be explained based on FIG. This has an exhaust gas treatment section integrated into the main reaction tube 1. That is, a cylindrical backflow prevention baffle 16 with a mouth-shaped cross section is provided in the center of the main reaction tube 1, and a front chamber (main reaction chamber) 11 for accommodating a sample and a backflow prevention baffle 16 for treating exhaust gas are provided. A rear chamber (exhaust gas treatment chamber) 18 is configured. The backflow prevention baffle 1G has its bottom wall facing the main reaction chamber 17 side, its four parts facing the exhaust gas treatment chamber 18 side, and the outside (circumferential direction between the iIQ wall and the inner wall of the main reaction tube 1). The exhaust gas generated in the main reaction chamber 17 is accelerated by this gap 19 and flows into the exhaust gas processing chamber 18, thereby preventing backflow.

Furthermore, a backflow prevention baffle 1 is installed in the exhaust gas treatment chamber 18.
A plurality of baffle plates 20 are provided to face G, and a pipe 21 for supplying oxygen gas is provided near the outlet side of the gap 19 between the backflow prevention baffle 16 and the baffle plate 20. . The open end of the exhaust gas treatment chamber 18 is sealed by a lid 5 to which an exhaust pipe 4 extending to the exhaust gas treatment device is connected. This device is constructed by removing the lid 5 and inserting a sample such as a wafer into the main reaction chamber 17, then inserting the backflow prevention baffle 16 and baffle plate 20 as shown in the figure, and finally sealing with the lid 5. It is now possible to perform heat treatment. Note that the backflow prevention baffle 1G and the baffle material 20 may be integrally formed at the intervals shown in the figure to facilitate attachment and removal.

Next, the operation of this device will be described. The sample in the main reaction chamber 17 is heat-treated by a reactive gas such as hydrogen gas supplied from the supply pipe 3 and heated by the electric furnace 2, and the generated exhaust gas is passed through the gap 19. The gas is accelerated and mixed with oxygen gas supplied from the pipe 21.

This warm gas is combusted by heating in the electric furnace 2 and further stirred by the baffle plate 20, so that the reaction of unreacted substances can be promoted.

This embodiment has a simpler configuration than the first embodiment, and has the advantage of reducing the burden on the exhaust gas treatment device. Further, by providing the baffle plate 20, backflow of exhaust gas can be completely prevented, and deposits can be efficiently removed from the exhaust gas.

FIG. 3 shows a third embodiment, in which the structure of the main reaction tube 1 in the second embodiment is modified. That is, the second
An opening to the right of the flange is formed on the tip side of the main reaction tube 1 shown in the figure, and the reaction gas is supplied to the main reaction chamber 17 through the supply pipe 3 that is in close contact with the flange and connected to a removable lid 22. It is supposed to be done. Further, the exhaust gas treatment chamber 18 is provided with a pipe 23 for supplying oxygen gas near the recess of the backflow prevention baffle 16, and a pipe 23 for supplying oxygen gas is installed in the exhaust gas treatment chamber 18, and a pipe 23 is provided in the exhaust gas treatment chamber 18 to supply oxygen gas to the vicinity of the recess of the backflow prevention baffle 16. 24 is connected to the exhaust gas treatment device.

In an apparatus having such a structure, the exhaust gas treatment I! can be performed by simply attaching and detaching the lid 22. 1! The sample can be inserted and taken out without moving the components on the side of the chamber 18, and the deposits 51 only need to be washed away, so there are advantages such as ease of use.

FIG. 4 shows a fourth embodiment, which is an improvement on the embodiments shown in FIGS. 2 and 3.

That is, the above 2. In the third embodiment, deposits not only adhere to the baffle plate 20 but also adhere to the inner wall of the main reaction tube 1, so that in the case of FIG. In this case, it becomes complicated to remove the backflow prevention baffle 1G and the baffle plate 20. In order to eliminate these problems, a cylindrical inner tube 24 with a diameter slightly smaller than the inner diameter of the main reaction tube 1 is installed on the exhaust gas treatment chamber 18 side of the main reaction tube 1, and is connected to the inner wall of the main reaction tube 1. Oxygen gas is supplied to a gap 25 formed between the interior 24 and the outer wall. A plurality of through holes 26 are formed along the circumferential direction on one side of the inner tube 22, and when the exhaust gas and oxygen gas generated in the front chamber 17 pass through the through holes 26, they become a mixed gas. It flows into the main reaction chamber 18. The mixed gas is further stirred by the baffle plate 20 provided inside the inner pipe 24 to promote the reaction of unreacted gas, and the exhaust gas from which deposits have been removed is passed through the exhaust pipe 4 for exhaust gas treatment. is discharged to. Here, since the deposits adhere to the inside of the inner tube 24, it becomes extremely easy to remove the basin for cleaning the inner tube 24, and the main reaction chamber 17
There is no possibility of contaminating the sample stored in the chamber. Furthermore, if the deposits are etched with hydrogen chloride gas or the like after taking out the sample, the deposits in the main reaction chamber 17 can be removed.
Furthermore, in this case, only the inner tube 24 is removed and washed, so the number of times the main reaction tube 1 is washed can be significantly reduced.

FIG. 5 shows a fifth embodiment, which is an improved version of the fourth embodiment shown in FIG. A sample can be taken in and out of the main reaction chamber 17 through a lid 27 that is in close contact with the main reaction chamber 17 and is removable. A supply pipe 3 for supplying a reaction gas is connected to one end of the lid 27.

Furthermore, an open end having a similar flange portion is formed at one end of the main reaction tube 1 on the side where the internal information 24 is arranged, and the exhaust pipe 4
Is it connected? ! The X28 is detachably attached to the flange. According to this structure, since the sample can be taken in and out and the inner tube 24 can be taken in and out from separate front ends, effects such as improved workability and maintenance can be obtained.

FIG. 6 shows a sixth embodiment, in which the internal configuration of the gas processing chamber 18 shown in FIGS. 4 and 5 is changed. That is,
L of inner tube 24! A pipe 29 for supplying oxygen gas is placed at a position slightly closer to the bottom wall than the first through hole 26, passing through one end of the lid 5, and an inert gas such as nitrogen gas is supplied through the pipe 21. It is designed to supply gas. With this configuration, the exhaust gas generated in the main reaction chamber 17 is
It is burned together with the oxygen gas supplied from the pipe 29, and deposits adhere to the bottom wall side of the inner pipe 24. Therefore, through hole 2
This reduces the amount of deposits adhering to G and also prevents deposits from adhering to the outer wall of the interior 24, simplifying maintenance. Note that a baffle plate may be provided in the rear chamber 18.

FIG. 7 shows a seventh embodiment, which has a structure that facilitates the loading and unloading of the sample and the loading and unloading of the inner tube 24 in the apparatus shown in FIG. Step 15: A front end having a flange is formed at the tip of the main reaction tube 1, and the sample can be taken in and out of the main reaction chamber 17 through the lid 30, which is in close contact with the flange and is detachable. It looks like this. Also, lid 30
A supply pipe 3 for supplying a reaction gas is connected to one end of the reactor. On the other hand, the rear end of the main reaction tube 1 also has a frontage end to the right of the flange part, and is provided with a receptacle 31 that is in close contact with the flange part and is detachable. The exhaust pipe 4 is connected to one end of the lid 31, and a pipe 29 for supplying oxygen gas into the exhaust gas processing chamber 18 is inserted into the exhaust gas processing chamber 18 through the lid 31.

With this configuration, the sample enters and exits the main reaction chamber 17 through the lid 30, and the inner tube 24 is attached and removed through the lid 31.
This can be done through a single holder, which simplifies maintenance.

FIG. 8 shows an eighth embodiment, which includes an outer tube 32 that further seals the outside of the main reaction tube 32. That is, a plurality of through holes 33 are formed at the rear end of the main reaction tube 1 so that exhaust gas generated within the main reaction tube 1 flows out to the outer tube 32 through the through holes 33. In addition, the outer tube 3 near the through hole 33
A pipe 34 for supplying oxygen gas is connected to one end of the outer pipe 2, and a pipe 4 extending to an exhaust gas treatment device is connected to the other end of the outer pipe 32. Furthermore, the piping 34 and the through hole 3
A baffle plate 35 is installed between the position where 3 is provided and the piping 4.
is provided. With this configuration, exhaust gas passes through the through hole 33, is mixed with oxygen gas supplied through the pipe 34, is further stirred by the baffle plate 35, and is discharged to the exhaust gas treatment device in a sufficiently combusted state. .

That is, the main reaction tube 1 and the outer tube, and the outer tube 32 are the main reaction tube 1.
and the furnace wall of the electric furnace 2, it is possible to prevent the sample from being contaminated by substances such as alumina and silicon carbide (SiC) from the furnace wall. Therefore, it is possible to improve the cleaning effect required when a sample is heat treated at high temperature, thermally oxidized, or thermally diffused.

In addition, in the fourth to seventh embodiments among the embodiments described above, when performing washing, N2. By supplying an inert gas such as Δr or 1-1e or a non-oxidizing gas (hydrogen gas, etc.), attached deposits can be easily removed and maintenance can be improved. However, in this case, it is necessary to perform the hydrogen treatment using the method described in the first embodiment or another method, which is effective in removing the deposits in a non-oxidized state.

Furthermore, in the second to seventh embodiments, if the electric furnace is configured to be able to independently change the temperature at which the sample is heated and the temperature at which the exhaust gas treatment is performed, Better effects can be obtained by controlling the exhaust gas treatment area by lowering the temperature to increase the amount of deposits, or by increasing the temperature to reduce the amount of unreacted gas.

In addition, it is easy to add to these embodiments the well-known designs and structures used in ordinary heat treatment equipment, such as a barge gas port to prevent outside air from being drawn in, a thermal lightning pair insertion port, an elephant tube, etc. I can do it. Further, although these embodiments have been described with respect to a horizontal furnace, the present invention can also be applied to a furnace with a vertical or inclined structure.

[Effects of the Invention] As explained above, according to the present invention, the exhaust gas generated in the main reaction tube is transferred to the sealed exhaust gas chamber 1! [! The combustion is done indoors with oxygen gas, and the exhaust gas that simulates combustion is discharged to an exhaust gas treatment device, etc., so there is a risk of explosion as the exhaust gas is discharged with unburned materials removed. This eliminates the need to dilute exhaust gas with inert gas and send it to the exhaust gas treatment device. In addition, even if exhaust gas containing depository reaction products is generated, the deposits are left behind due to combustion in the exhaust gas treatment chamber.
The load on the exhaust gas treatment device is reduced, and H2 treatment can be easily performed. Furthermore, the apparatus can be easily constructed and can be easily applied to conventional heat treatment apparatuses.

[Brief explanation of the drawing]

1 to 8 are schematic cross-sectional views showing the structure of an embodiment of a heat treatment apparatus for semiconductor devices according to the present invention, and FIGS. 9 and 10 are schematic cross-sectional views showing the structure of a conventional heat treatment apparatus. 1... Main reaction tube 2... Electric furnace 3... Supply pipe 4... Exhaust pipe 5... Lid 6... Seed Fire 7... Piping 8... Piping 9. ...Exhaust gas treatment furnace 10...Electric furnace 11...Reaction tube 12...Baffle plate 13...Inflow port 14...Piping 15...Exhaust pipe 16...Baffle for backflow prevention 17... Main reaction chamber 18... Exhaust gas processing chamber 19... Gap Question 20... Baffle plate 21... Piping 22... Lid 23... Piping 24... Inner pipe 25... Gap 26... Opening hole 27... Lid 28... Lid 29... Piping 30... Lid 31... Lid 32... Outer Pipe 33... Penetration Hole 34...Piping 35...Baffle plate

Claims (1)

[Scope of Claims] A heat treatment apparatus for semiconductor devices comprising a heating furnace and a main reaction tube housed in the heating furnace, and heat-treating a sample placed in a reaction gas atmosphere in the main reaction tube, comprising: A heat processing apparatus for semiconductor devices characterized by comprising a sealed exhaust gas processing chamber in which exhaust gas generated in a main reaction tube is mixed with oxygen gas and combusted in the middle of an exhaust path.