JP2700939B2 - Sealing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a sealing device.

(Prior Art) In a general heat treatment apparatus, a sealing means interposes an O-ring between a lid closing an open end with an open end flange portion of a processing container evacuated by a vacuum pump, and seals the processing container. A method for maintaining airtightness is widely used.

In addition, a plurality of seals using a fluororesin material with a built-in spring and a plurality of grooves arranged coaxially and in parallel with the seals are provided. ters for differential
ly pumped rotating plat-forms ", Rev. Sci. Instrum. 58
(2) There is a means described in February 1987 P309, P310.

(Problems to be Solved by the Invention) When the former O-ring is used as a sealing member, the O-ring is a flexible member made of fluoro rubber or the like, and generally has a heat-resistant temperature of about 200 ° C. When the temperature of the portion exceeds this temperature, the O-ring is melted and deformed, and a desired vacuum sealing effect cannot be obtained.
Although the vicinity of the ring is cooled to protect the O-ring, there is an improvement in that the processing vessel becomes longer due to the necessity of obtaining a soaking length in the heat treatment region.

When the O-ring is replaced by stopping the heat treatment apparatus, when the O-ring cools down to room temperature, the O-ring is fixed to the sealing portion (in a crimped state), making it difficult to remove the O-ring. Such as removing tubes
There is an improvement to break this expensive quartz tube. Furthermore, the gas and moisture contained in the O-ring are released due to the high temperature during the heat treatment, and the amount of the release varies depending on the pressure, time, and temperature. When heat treatment of the body is performed, a large variation occurs between processing lots unless the evacuation is performed for a long time after the pressure reaches a predetermined pressure and the gas and the water content are sufficiently released from the O-ring. There is an improvement point. The sufficient gas release time degrades the throughput.

Also, in the reduction heat treatment for removing the natural oxide film of the object to be treated using a treatment gas such as monosilane (SiH ₄ ), even if the gas is sufficiently exhausted by a vacuum pump, the release of gas and water content from the O-ring cannot be ignored. And that the desired reduction heat treatment cannot be performed.

Next, in the latter technique shown in the above-mentioned literature, the heat-resistant temperature is around 200 ° C. because the fluororesin is used as the sealing member, and when the temperature of the sealing portion is equal to or higher than this temperature in the heat treatment apparatus, the same improvement points as described above are made. Having.

(Objects of the Invention) The present invention has been made in view of the above points, and a sealing device that does not contain unnecessary oxygen or moisture in the atmosphere in a container, does not emit gas due to high temperature, and does not require cooling. Is provided.

(Means for Solving the Problems) In the sealing device according to the first aspect of the present invention, the object to be treated is carried into the reaction vessel from an open end, the open end is closed by a lid, and the inside of the reaction vessel is closed. A heat treatment apparatus for performing heat treatment on the object to be processed in a decompressed state, wherein an exhaust groove opening at least one of an end face of the opening end and an outer peripheral face of the lid facing the end face, Exhaust means for exhausting between the open end and the joint surface of the lid via the exhaust groove; and at least one of an end face of the open end and an outer peripheral surface of the lid facing the end face. A pressurizing groove that is open and located outside the exhaust groove, a metal sheet covered over the opening of the pressurizing groove, and a pressurizing gas that supplies a pressurized gas into the pressurizing groove. A gas supply path; A pressurized gas is supplied into the groove for exhaust gas and the metal sheet is brought into close contact with the opposite surface, and exhausted through the exhaust groove to prevent gas leakage between the reaction vessel and the lid. It is characterized by stopping.

The sealing device according to a second aspect of the present invention is the sealing device according to the first aspect of the present invention, such that an outer peripheral surface of the lid body facing the end surface of the opening end portion is further away from the end surface toward the inside of the reaction vessel. The end face is inclined relative to the end face, and when the inside of the reaction vessel is in a reduced pressure atmosphere, the lid is deformed so as to be drawn into the inside of the reaction vessel so that the end face and the outer peripheral face of the lid become parallel. It is characterized by comprising.

In the sealing device according to the third aspect of the present invention, the object to be processed is carried into the reaction vessel from an open end, the open end is closed by a lid, and the inside of the reaction vessel is evacuated to a pressure. A heat-treating apparatus for performing heat treatment by heating, comprising: an exhaust groove opening on at least one of an end surface of the opening end and an outer peripheral surface of the lid facing the end surface; and the opening facing the exhaust groove. A protrusion formed on an end surface of the end portion or an outer peripheral surface of the lid and inserted into the exhaust groove, and between the opening end and the joining surface of the lid through the exhaust groove. Exhaust means for exhausting the gas, and an outer peripheral surface facing the end surface of the opening end of the lid is inclined relative to the end surface so as to be further away from the end surface toward the inside of the reaction vessel. And the inside of the reaction vessel is in a reduced pressure atmosphere. In the case of air, the lid deforms so as to be drawn into the inside of the reaction vessel so that the end face and the outer peripheral surface of the lid become parallel, and the protrusion is inclined outward to contact the exhaust groove, Further, gas leakage between the reaction container and the lid is sealed by exhausting gas through the exhaust groove.

(Example) Hereinafter, an example in which the apparatus of the present invention is applied to a batch type vertical heat treatment apparatus will be specifically described with reference to the drawings.

In FIG. 1, a vertical process tube 10 is made of a heat-resistant material such as a quartz-made cylindrical tube. One end of a cylindrical manifold 20 is hermetically sealed at the lower end opening end (flange portion) of the tube 10. A gas introduction tube 26 is connected to the side wall of the manifold 20 in an airtight manner,
An exhaust pipe 28 is further hermetically connected to the side wall of the manifold 20, and a process tube is provided by an exhaust pump (not shown).
It is configured so that the inside of 10 can be evacuated.

Around the process tube 10, a cylindrical resistance heater 16 having at least a three-zone configuration is provided,
A desired temperature, for example, 500 to 120 inside the process tube 10
The temperature can be appropriately set within a range of 0 ° C., and the accommodation area of the object to be processed is configured to be uniformly heated. The above process tube
A large number of semiconductor wafers 18 as objects to be processed are horizontally accommodated in a wafer boat 17 made of, for example, quartz at predetermined intervals. Is set on the lid 40 and stored.

The lid 40 can be moved up and down while supporting the wafer boat 17 by the elevating mechanism 50, and is configured so that the wafer 18 can be loaded and unloaded into the process tube 10 to a predetermined soaking area position. I have.

The lower end opening end 22 of the other end of the manifold 20 that contacts the lid 40 is hermetically sealed. The details of the sealing mechanism will be described below with reference to FIG. However, in this embodiment, the assembly of the process tube 10 and the manifold 20 constitutes a reaction vessel.

At least one of the facing surfaces of the lid 40 to be hermetically sealed and the flange portion of the opening end 22 of the manifold 20, for example, annular grooves 30, 32, 34 are provided on the facing surface on the manifold 20 side, of which the grooves 30, 32 are provided. Exhaust holes 31 and 33 are provided at the bottom of the manifold 20 so as to be connected to each other in the wall surface of the manifold 20, and can be evacuated by a vacuum pump (not shown) serving as an exhaust unit together with the exhaust holes 31 and 33.

A gas introduction hole 35 is similarly provided at the bottom of the groove 34 so as to be connected within the wall surface of the manifold 20, so that an inert gas such as a nitrogen gas can be supplied from a gas supply source (not shown). In this example, the gas introduction hole 35 and the gas supply source constitute pressurized gas supply means.

The manifold 20 and the lid 40 are made of a corrosion-resistant metal such as stainless steel.
44. For example, a 0.1mm thick silver (Ag) thin plate (stainless steel or nickel)
The lower end 36, 37, 38, 39 of 22 is mirror-finished and has a surface roughness of ±
The flatness is 2 μm or less and the flatness is ± 5 μm or less in the entire plane formed by the lower end surfaces 36, 37, 38 and 39.

The surface roughness of the outer peripheral surface 42 of the lid 40 in contact with the manifold 20 is ± 2 μm or less, and the flatness similar to the above is ± 5 μm.
m or less.

The traces during processing when applying the above processing are manifold
It is formed so as to be concentric with the center of 20 and the lid 40.

 Next, the operation of the above embodiment will be described.

The temperature of the soaking area in the process tube 10 is set to, for example, 1000 ° C. by the heater 16, the elevating mechanism 50 is moved upward, the wafer boat 17 containing the wafer 18 is loaded, and the manifold 20 and the lid Set 40 to the abutted state.

While the supply of the processing gas to be supplied to the gas introduction pipe 26 is stopped, the inside of the process tube 10 is exhausted by an exhaust pump (not shown) via the exhaust pipe 28. In this example, the atmosphere inside the process tube 10 and the atmosphere outside the same correspond to a first gas atmosphere and a second gas atmosphere, respectively.

Further, exhaust is performed by a vacuum pump (not shown) through the exhaust holes 31 and 33 connected to the grooves 30 and 32.

Nitrogen gas is introduced into the introduction hole 35 connected to the groove 34 by 4 to 5 kg / cm.
^When supplied at a pressure of ² , the thin silver plate 44
The thin plate 44 and the outer peripheral surface 42 are air-tightly sealed by being expanded and deformed so as to be in close contact with the portion. This sealing groove is provided in the outer groove of the vacuum groove. There is also a slight leak from the hermetic sealing portion, and a small amount of air flowing in from the leak portion is evacuated by a vacuum pump connected to the groove 32, and the pressure in the groove 32 is about 0.01 Torr. Similarly, the pressure of the evacuated groove 30 is 1 × 10 ⁻⁴ Torr.
Before and after, the pressure inside the process tube 10 can be set to a preset pressure of 1 × 10 ⁻⁸ Torr or less.

In such a sealed state, a required amount of monosilane (SiH ₄ ) gas is supplied through the gas introduction pipe 26 to reduce the natural oxide film formed on the silicon wafer 18 as the object to be processed. The desired processing was performed.

As described above, since the seal portion between the manifold 20 and the lid 40 is air-tightly sealed and performs a stepwise differential exhaust of the pressure value, oxygen or moisture in the air does not enter the process tube 10. .

In addition, since the O-ring does not use the sealing portion, there is no gas or moisture released from the O-ring, and a desired pressure can be reached in an end time, and the O-ring cannot be used.
Sealing can be performed at a high temperature of 200 ° C. or higher.

Further, if the number of grooves provided at the lower end portion 22 of the manifold 20 is increased as necessary, the pressure inside the process tube 10 can be further reduced, and conversely, the grooves to be evacuated according to the required pressure value are It is not necessary to provide it.

In another embodiment, as shown in FIG. 3, the outer peripheral surface 42 of the lid 40 facing the lower opening end 22 of the manifold 20 is inclined inward. The same parts as those in FIG. 1 are indicated by the same reference numerals and the description is omitted.

When the inside of the process tube 10 is evacuated, the lid 40 is pressed at a pressure of 1 kg / cm ² by the atmospheric pressure, the central portion of the lid is deformed to the process tube side, and the lid 16 is heated by the heater 16 and heated. There is a temperature difference between the upper and lower surfaces of
Are deformed in the same direction as above. Therefore, the outer surface 42 of the lid 40
The outer peripheral surface 42 and the surfaces of the lower end portions 36 to 39 of the manifold 20 are parallel to each other in a state where they are inclined.

Since the inclination angle θ varies depending on the size, thickness, material, temperature of the heater 16 and the like of the lid 40, the inclination angle is appropriately set so that the two surfaces are parallel at the time of required operation.

As an example of the case where the inclination angle is given, the diameter of the lid is 300 mm, the thickness is 12 mm, and the material is stainless steel SUS 3
When the temperature of the heater is 1000 ° C., the optimum inclination angle θ is in the range of 0.01 to 0.1 degrees.

In another embodiment, as shown in FIG. 4, the technology according to the present invention is applied to a contact portion between a lower end edge 11 of a process tube 10 and an upper end portion 24 of a manifold 20.

Annular grooves 60, 62, 64 are provided at the upper end surface of the upper open end 24 of the manifold 20 that comes into contact with the process tube 10, and exhaust grooves 61, 63 are connected to the grooves 60, 62 so that exhaust can be performed by a vacuum pump (not shown). And

A groove plate 45 is hermetically welded to the entire circumference of the opening of the groove 64. A gas introduction pipe 65 is connected to the groove 64 so that an inert gas such as a nitrogen gas can be supplied from a gas supply source (not shown).

Upper end 66, 67, 6 including thin plate 45 of manifold 20
The working accuracy of the 8,69 surface is the same as in the above embodiment.

The surface roughness of the lower edge 11a of the lower end 11 of the process tube 10 in contact with the manifold 20 is ± 2 μm or less,
The flatness is ± 5 μm or less.

When the process tube 10 is heated to, for example, 1000 ° C. by the heater 16, the temperature of the lower edge 11 of the process tube 10 is
The temperature is about 300 ° C., and under such use conditions, vacuum sealing can be performed only by using the present invention.

As still another embodiment, as shown in FIG. 5, a groove 34 is formed in a lid 40 portion facing the lower opening end 22 of the manifold 20.
Some have a projection 46 provided so as to be disposed inside.

The groove 34 can be evacuated by a vacuum pump (not shown) via an exhaust pipe 48. Other parts that are the same as those in FIG.

 Next, the operation of the above embodiment will be described.

When the lid 40 is brought into contact with the manifold 20 by moving the elevating mechanism 50, the projection 46 and the groove 34 are in a non-contact state.

Next, when the inside of the process tube 10 is evacuated, the lid 40
The center of the lid 40 pressed at atmospheric pressure is deformed toward the process tube. Further, the temperature is different between the upper surface and the lower surface of the lid 40 by being heated by the heater 16, and the lid 40 is deformed in the same direction as described above.

As a result, the projection 46 disposed in the groove 34 is deformed so as to expand in the circumferential direction, and the groove 34 and the projection 46 come into contact with each other to form a seal portion.

By the vacuum evacuation of the seal portion and the groove portions 30, 32, and 34 and the evacuation action in the process tube 10, the same sealing effect as that of the first embodiment and the processing result of the object to be processed can be obtained.

In order to increase the amount of deformation of the lid 40 due to the atmospheric pressure, it is also effective to reduce the thickness of the lid 40.

When opening the lid 40 from the manifold 20, the lid
It is preferable to reduce the amount of thermal deformation of the forty.

Therefore, a cooling water pipe is provided on the lid 40, and
And the amount of thermal deformation of the lid 40 can be controlled.

Note that the present invention is not limited to the above embodiment,
Various modifications can be made within the scope of the present invention.

Needless to say, a plurality of grooves provided in the manifold may be provided in the lid. The material of the lid may be a non-metal such as quartz or SiC other than metal.

Although the reduced pressure heat treatment apparatus has been described in the above embodiment, it may be applied to a heat treatment apparatus such as a diffusion furnace or a normal pressure CVD apparatus and other batch processing apparatuses, and is applicable not only to a vertical apparatus but also to a horizontal apparatus. Of course.

In the above-described embodiment, an example is described in which a groove is provided on one surface of the seal opposing surface, but a groove may be formed on both opposing surfaces. In this case, they may be provided at the same position facing each other or at positions shifted from each other.

〔The invention's effect〕

As described above, according to the present invention, it is possible to form a seal portion that can withstand a high temperature at which an O-ring or the like cannot be used, and no unnecessary atmospheric components are mixed into the container, and thus a desired process can be performed. There is a remarkable effect that the body can be applied.

[Brief description of the drawings]

1 is an explanatory view of one embodiment of a vertical heat treatment apparatus according to the present invention, FIG. 2 is a partial explanatory view of FIG. 1, FIG. 3 is an explanatory view of another embodiment of FIG. 2, and FIG. FIG. 1 is an explanatory view of another embodiment of FIG.
FIG. 5 is an explanatory view of another embodiment. 10 Process tube, 16 Heater 17 Boat, 18 Wafer 20 Manifold 22, 22 Open end 30, 32, 34 Groove, 31, 33 Exhaust pipe 35 Tube, 36-39 Bottom end 40 Lid 42 Outer peripheral surface 44, 45 Thin plate 46 Projection 50 Lifting mechanism

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication location H01L 21/205 H01L 21/205 (56) References JP-A-55-78859 (JP, A) Kaihei 3-249936 (JP, A) Japanese Utility Model Showa 61-146662 (JP, U) Japanese Utility Model Showa 57-31273 (JP, Y2) Japanese Utility Model Hei 2-3109 (JP, Y2)

Claims (3)

(57) [Claims] 1. A heat treatment apparatus for carrying an object to be treated into an inside of a reaction vessel from an open end, closing the open end with a lid, and performing heat treatment on the object to be treated. An exhaust groove opening on at least one of the outer peripheral surfaces of the lid facing the end face, and exhaust exhausting between the opening end and the joining surface of the lid via the exhaust groove. Means, a pressurizing groove which is open on at least one of an end surface of the opening end and an outer peripheral surface of the lid facing the end surface and which is located outside the exhaust groove, and a pressurizing groove. And a pressurized gas supply path for supplying a pressurized gas into the pressurizing groove, wherein the pressurized gas is supplied into the pressurized groove and the metal thin plate is provided. To the opposite surface of the Sealing apparatus characterized by sealing the leakage of gas between the reaction vessel and the lid by evacuating through the groove of use. 2. The reaction container according to claim 1, wherein an outer peripheral surface of the lid facing the end surface of the open end is inclined relative to the end surface so as to be further away from the end surface toward the inside of the reaction vessel. 2. The sealing device according to claim 1, wherein the lid is deformed so as to be drawn into the inside of the reaction vessel when the inside is in a reduced-pressure atmosphere, so that the end face and the outer peripheral surface of the lid are parallel to each other. Stop device. 3. A heat treatment apparatus for carrying out a heat treatment on an object to be processed, wherein the object to be processed is carried into the reaction container through an open end while the inside of the reaction vessel is depressurized, and the open end is closed by a lid. An exhaust groove opening on at least one of an end face of the opening end and an outer peripheral surface of the lid facing the end face; and an end face of the opening end facing the exhaust groove or the lid. A protrusion formed on the outer peripheral surface of the body and inserted into the exhaust groove; and an exhaust unit configured to exhaust air between the open end and the joint surface of the lid via the exhaust groove. An outer peripheral surface facing the end surface of the open end of the lid is inclined relative to the end surface so as to be further away from the end surface toward the inside of the reaction vessel, and the inside of the reaction container is The above lid in a reduced pressure atmosphere Is deformed so as to be drawn into the inside of the reaction vessel so that the end surface and the outer peripheral surface of the lid are parallel to each other, and the protrusion is inclined outward to contact the exhaust groove, and the exhaust groove is formed. A gas leaking between the reaction vessel and the lid by evacuating the gas through the sealing device.