JPH07201760A - Heat-treating device - Google Patents

Abstract

PURPOSE:To obtain a device which prevents the gradation region of process gas from being generated in a treating container by providing a plurality of pieces of specified exhaust vents in a mount stage or/and on the periphery of the mount stage and the like, causes no unevenness of a temperature in materials themselves to be treated, and can treat the materials with the process gas acting on the materials to be treated without a gradation. CONSTITUTION:A plurality of materials W to be treated are housed in a housing boat 9, the boat 9 is carried in a treating container 5 through the opening part of the container 5 and a heat treatment is performed on the materials W while process gas is fed to the materials W through a gas introducing means 15. In such a heat- treating device, an opening and shutting mechanism 12 to seal the opening part of the container 5 in an openable and closeable manner and a mount stage 29, which is coupled with the mechanism 12 and at the same time, is placed with the boat 9, are provided. Moreover, exhaust vents 31, which are provided in the stage 20 or/and on the periphery of the state 20 and are arranged in a plurality of pieces and equally along a prescribed diameter centering around the center axes of the materials W, are provided and those vents 31 are controlled in such a way that they are respectively evacuated at an exhaust amount of the same amount.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a heat treatment apparatus such as a vertical CVD processing apparatus.

[0002]

2. Description of the Related Art An object to be processed, for example, a semiconductor wafer is kept in a uniform temperature state, a processing gas is supplied to the object to be processed, and a predetermined heat treatment is performed to form a thin film on the surface of the object to be processed or to diffuse heat. As a heat treatment apparatus for performing heat treatment, Japanese Patent Laid-Open No. 56-91417
Japanese patent publication is disclosed.

In this technique, a wafer holder for accommodating a plurality of objects to be processed is loaded into a container, and a processing gas is introduced through a gas inlet provided at an upper portion of the container, and a lower portion of the container, The inside of the container is exhausted from one gas outlet provided on the wall, and the inside of the container is set to a predetermined pressure to process the object to be processed.

[0004]

However, since the exhaust port for exhausting the processing gas is composed of one gas outlet provided on the wall of the container, the processing gas will flow toward the exhaust port. As a result, the gas concentrates around the vicinity of the gas exhaust port to form a region having a high gas density. Also,
Since this processing gas is processed by maintaining the object to be processed at a predetermined temperature, it is heated to the same temperature, and the temperature of the region having a high gas density becomes higher than that of the region having a low gas density, There was a problem that the temperature was uneven in the container. In addition, due to this temperature unevenness, the temperature of the exhaust port side of the object to be processed becomes higher than that of the non-exhaust port side, and there is a problem that the object to be processed itself has uneven temperature. If the temperature unevenness occurs in itself, the object to be processed cannot be uniformly processed, and the yield of the object to be processed decreases.

The object of the present invention is to prevent the generation of a concentrated region of the processing gas in the processing container, to prevent the non-uniformity of the object to be processed due to the temperature, and to act without the processing gas being concentrated. An object of the present invention is to provide a heat treatment apparatus capable of processing.

[0006]

According to the present invention, a plurality of objects to be processed are housed in a housing boat, and the housing boat is carried into the processing container through an opening provided in the processing container. A heat treatment apparatus for performing heat treatment while supplying a processing gas from a gas introduction means, the opening / closing mechanism for opening and closing the opening of the processing container so that the opening can be opened and closed, and the accommodation boat mounted on the opening and closing mechanism. A mounting table; and a plurality of exhaust ports provided around the mounting table and / or around the mounting table and arranged uniformly around a center axis of the object to be processed. However, the plurality of exhaust ports are configured to be exhausted at the same exhaust amount.

[0007]

According to the present invention, there is provided a mounting table for mounting a storage boat for accommodating a plurality of objects to be processed, and / or a periphery of the table, along a predetermined diameter centered on the central axis of the object. The same amount of exhaust air is exhausted from each of the plural, evenly arranged exhaust ports, so that the concentration of the processing gas in the radial direction around the center axis of the object to be processed is prevented. In addition, it is possible to prevent the temperature unevenness due to the concentration of the processing gas.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vertical CVD processing apparatus as an embodiment of a heat treatment apparatus according to the present invention will be described in detail below with reference to the accompanying drawings.

As shown in FIG. 1, this CVD processing apparatus 1
The heating furnace 2 of the above is an inner tube 3 made of quartz with an upper opening and a lower opening.
And a processing container 5 composed of a quartz outer tube 4 which is concentrically arranged at a predetermined distance from the outer periphery and has a ceiling and an opening at the lower side. The heater 6 is wound. An outer shell 8 made of, for example, stainless steel is provided on the outer periphery of the heater 6 via a heat insulating material 7 to form a heating furnace 2 as a whole. Then, by controlling the heater 6, the inside of the processing container 5 can be appropriately set within a range of 500 to 1200 ° C., for example.

In the inner tube 3, a plurality of objects to be processed, for example, semiconductor wafers, made of quartz, for example, are stacked on a wafer boat 9 as a receiving boat for accommodating the objects to be processed and stacked vertically at a predetermined pitch. W is housed so that it can be inserted and removed freely. A cylindrical manifold 10 made of, for example, stainless is connected to the lower ends of the inner pipe 3 and the outer pipe 4, and an annular upper flange 10A is formed at the upper end of the manifold 10. At the same time, the flange portion 4 of the outer tube 4 is attached to the upper flange portion 10A.
A is airtightly placed via the O-ring 11.

A ring-shaped middle flange 10B is formed in the middle of the manifold 10 so as to project inward, and the lower end 3A of the inner tube 3 is formed in the middle flange 10B by an inner tube receiving ring. The diameter is slightly increased, and it is placed and supported. A ring-shaped lower flange 10C protruding outward is formed at the lower end of the manifold 10, and the lower flange 10C is provided with an opening / closing means, for example, a cap 12 made of stainless steel. The opening of the container 5 is airtightly provided via a ring 13 so as to be opened and closed.

Further, the manifold portion 10 is provided with a processing gas introducing nozzle 15 as a gas introducing means for introducing the processing gas into the container, and the tip of the introducing nozzle 15 has an inner pipe 3 The introduced processing gas is communicated with the gap between the inner tube 3 and the outer tube 6 and rises in the gap between the inner tube 3 and the outer tube 6, and a predetermined circumference around the central axis O of the object W to be processed. The processing gas is evenly distributed along the direction.
It is configured to be introduced downward from the vicinity of the upper part of.

The wafer boat 9 includes a mounting table,
For example, the heat insulating cylinder 20 is placed on the heat insulating cylinder 20 via a spacer member 21 made of, for example, quartz, and the heat insulating cylinder 20 is hermetically sealed through the O-ring 13 at the opening of the processing container of the manifold section 10. It is directly supported and fixed on the cap portion 12 made of, for example, stainless steel for sealing.

The cap portion 12 is fixed to the tip of an arm portion 26 of an elevating means 24 composed of an elevator or the like. By driving this, the whole wafer boat 9 is vertically moved up and down to process it. It is designed to carry in and out. And the heat insulation cylinder 20
Is made of, for example, quartz and has a cylindrical shape centered on the central axis O of the semiconductor wafer W, and a heat insulating material such as glass wool 30 is filled in the heat insulating cylinder 20.

Further, the heat retaining cylinder 20 has a plurality of exhaust ports 31 having a predetermined diameter centered on the central axis O of the object to be processed W, which are evenly arranged on the side wall of the heat retaining cylinder 20, for example.
Is provided. Each of these exhaust ports 31 is connected to an exhaust thin pipe 32, and the exhaust thin pipes 32 are bundled and connected to an exhaust means 33, for example, an exhaust pipe 34 connected to a vacuum pump. And this exhaust pipe 34
Is provided on the central axis O of the semiconductor wafer W in order to exhaust the same amount from each of the plurality of exhaust ports 31.

As other means for making the exhaust amounts of the respective exhaust ports 31 the same, the opening diameter or opening shape of each exhaust port 31 is changed, or the length and the pipe of the exhaust thin tube 32 are changed. The diameter of the exhaust system may be changed so that the contact characteristics of the exhaust system are the same in each opening.

Next, the operation of this embodiment configured as described above will be described.

First, the wafer boat 9 in which a large number of semiconductor wafers W are accommodated at a predetermined pitch is lifted by the elevating means 24 and loaded into the processing container 5, and the cap 12 closes the opening of the manifold 10. The inside of the processing container 5 is sealed. Then, a predetermined amount of processing gas is supplied from the processing gas introduction nozzle 15, and the inside of the container 5 is evacuated from the plurality of exhaust ports 31 via the exhaust pipe 34 by the vacuum pump 33,
The inside of this is set to a predetermined pressure, for example, 0.5 Torr. Further, the inside of the processing container 5 is set to a predetermined temperature, for example, 800 ° C. by the heater 6.

Here, the processing gas introduced from the processing gas introduction nozzle 15 rises in the gap between the inner tube 3 and the outer tube 6 and is introduced from the vicinity of the upper portion of the wafer boat 9 in the lower direction X, It is made to flow into the wafer holding area Y. When the processing gas passes through the wafer holding area, the semiconductor wafer W interacts with the processing gas to form a predetermined film. Furthermore, the processing gas is
Exhaust means 33 that passes through the entire wafer holding area Y and is exhausted from a plurality of exhaust ports 31 via exhaust thin tubes 32 and exhaust tubes 34.
More exhausted. At this time, the inside of the processing container 5 is the exhaust means 3.
It is maintained at a predetermined pressure by controlling the exhaust amount of No. 3.

Next, the effect of this embodiment will be described.

As shown in FIG. 2a, in the conventional apparatus, the processing gas introduced from the processing gas introduction nozzle 15 is exhausted from one gas outlet, so that the processing gas flow X1 is at one point. Area 50 where the processing gas is concentrated because it is concentrated
Occurs. On the other hand, in this embodiment, as shown in FIG. 2B, the gas is exhausted from each of the plurality of exhaust ports 31 with an equal exhaust amount, so that the semiconductor wafer W is processed in the radial direction about the central axis O. Gas concentration does not occur,
Further, it is possible to improve the non-uniformity of the temperature due to the concentration of the processing gas.

Thus, the central axis O of the semiconductor wafer W is
Since there is no concentration of processing gas and uneven temperature in the radial direction centered on the center of the semiconductor wafer W, the semiconductor wafer W itself does not have unevenness due to temperature, and the processing gas can act on the semiconductor wafer W without concentration. it can. Further, since there is no temperature nonuniformity, the temperature of the members forming the processing container 5, such as the inner tube 3, the outer tube 4, the cap 12 and the like, and the internal members of the processing container 5, such as the heat insulating cylinder 20 and the wafer boat 9, is uniform. Therefore, it is possible to prevent damage (cracks, etc.) or deformation of the member itself due to the temperature difference.

Further, since the thin exhaust pipe 32 is provided in the heat retaining cylinder 20, high heat due to the processing gas is evenly permeated, the heat insulating effect can be further enhanced, and the uniform heating area in the processing container can be lengthened. Therefore, the height of the heat insulating cylinder 20 can be shortened, which allows the height of the device itself to be shortened, and the device itself can be miniaturized.

Next, another embodiment of the exhaust system will be described.

As shown in FIG. 3A, the cap portion 12 disposed below the heat retaining cylinder 20 has a predetermined diameter centered on the central axis O as shown in FIG. A plurality of exhaust ports 31 that are placed and have a diameter equal to or larger than the placement area 20A and that are evenly arranged are provided to form an exhaust system passage. With this configuration, the structure of the heat retaining cylinder 20 is not complicated and the strength of the heat retaining cylinder 20 can be maintained. Further, it is possible to reduce the load on the heat insulating cylinder 20 due to thermal stress. Further, in addition to the cap portion 12, an exhaust system passage may be separately arranged around the heat retaining cylinder 20, or the exhaust systems described above may be used in combination.

Next, another embodiment of the gas introducing means will be described.

As shown in FIG. 4A, the processing gas introducing nozzle 15 for supplying the processing gas is arranged on the central axis O of the semiconductor wafer W. With this configuration, the flow of the processing gas X can be made to flow uniformly in the radial direction centered on the central axis O of the semiconductor wafer W, and the processing gas can be uniformly applied to the semiconductor wafer W. Further, as shown in FIG. 4B, a gas diffusion portion 51 is provided at the tip of the processing gas introduction nozzle 15 and a plurality of small holes 52 are provided on the side of the semiconductor wafer W, so that the processing gas can be made wider and more uniform. Can flow in.

Further, as shown in FIG. 5, the processing gas introducing nozzles 15 are arranged on the central axis O of the semiconductor wafer W and are provided corresponding to the semiconductor wafers W held in the storage boat 9, respectively. Has been done. With this configuration, the processing gas can be uniformly applied to each of the semiconductor wafers W and can be processed uniformly, and the amount of the processing gas blown out from each processing gas introduction nozzle 15 can be increased. When there is a semiconductor wafer that is slow in processing depending on the location of the storage boat 9, it is possible to flow a larger amount of processing gas as compared with the location where the processing is fast. This improves the leveling of processing.

The exhaust ports may be evenly provided, for example, on the container side, for example, on the manifold portion 10 along a predetermined circumferential direction centering on the central axis of the object to be processed. Further, although the low pressure CVD apparatus has been described as an example in the above embodiment, the present invention is not limited to this, and any heat treatment apparatus using a processing gas such as a normal pressure CVD apparatus can of course be applied. Although the semiconductor wafer is used as an example of the object to be processed, it is needless to say that the object to be processed may have an angular shape such as an LCD substrate.

[0030]

According to the present invention, the concentration of the processing gas is prevented from being generated in the radial direction around the central axis of the object to be processed, and the temperature nonuniformity associated with the concentration of the processing gas is also improved. Therefore, the object to be processed can be processed by causing non-uniformity due to the temperature itself and by allowing the processing gas to act without being concentrated, and the yield of the object to be processed can be improved.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a heat treatment apparatus according to the present invention.

[Fig. 2]

FIG. 10A is a schematic cross-sectional view illustrating the operation of a conventional heat treatment apparatus.

1B is a schematic cross-sectional view explaining the operation of the device shown in FIG.

[Figure 3]

[A] It is a schematic cross-sectional view for explaining another embodiment of the exhaust system.

FIG. 7B is a schematic plan view illustrating another embodiment of the exhaust system.

[Figure 4]

[A] It is a schematic sectional drawing explaining the Example of another gas introduction means.

[B] It is a partial cross-sectional view for explaining an embodiment of another gas introducing means.

FIG. 5 is a partial cross-sectional view for explaining an embodiment of another gas introduction means.

[Explanation of symbols]

 5 Processing Container 9 Wafer Boat (Processing Object Storage Boat) 10 Manifold Part 12 Cap Part 15 Gas Introducing Means 20 Heat Retaining Cylinder 24 Elevating Means 31 Exhaust Ports 32 Exhaust Tubes 33 Exhaust Means 34 Exhaust Pipes W Semiconductor Wafers (Processing Objects)

Claims (6)

[Claims] 1. A plurality of objects to be processed are housed in a housing boat,
A heat treatment apparatus for carrying in this storage boat into a processing container through an opening provided in a processing container and performing heat treatment while supplying a processing gas to the object to be processed from a gas introduction means, the opening of the processing container. An opening and closing mechanism that can open and close the
A mounting table which is connected to the opening / closing mechanism and on which the accommodation boat is mounted, and the mounting table or / and the surroundings of the mounting table, along a predetermined diameter centered on the central axis of the object to be processed. A plurality of and uniformly arranged exhaust ports are provided, and the plurality of exhaust ports are configured to be exhausted with the same exhaust amount, respectively. 2. The heat treatment apparatus according to claim 1, wherein the mounting table is a heat insulating cylinder having heat insulating properties. 3. The heat treatment apparatus according to claim 1, wherein the gas introduction unit and the exhaust port are arranged with the accommodation boat interposed therebetween. 4. The gas introducing means is evenly provided on the central axis of the object to be processed and / or along a predetermined circumferential direction centered on the central axis of the object to be processed. The heat treatment apparatus according to claim 1. 5. The heat treatment apparatus according to claim 1, wherein the gas introducing unit is arranged on the central axis of the object to be processed and provided corresponding to the object to be processed. 6. The heat treatment apparatus according to claim 1, wherein the exhaust ports are evenly provided on the container side along a predetermined circumferential direction centered on a central axis of the object to be processed.