JP2012234981A - Decompression processing container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decompression processing container which has superior heat resistance, high intensity, and low heat capacity and can easily be carried.SOLUTION: A thin inner container 11 formed in a cylindrical shape by stainless steel and a thin outer container 17a which forms a vacuum insulation space 13 between the inner container 11 and the outer container, is formed in the cylindrical shape by the stainless steel, and in which a plurality of rib-like undulations 15 are formed on an outer peripheral face are bonded, and a dual structure is obtained. The structure uses a base plate 19 of a metallic material, especially the stainless steel, whose thickness is made to be not more than that of the inner container 11, which absorbs an interval change between the inner container 11 and the outer container 17a and has a U-shaped cross section, for example. The container has the low heat capacity, the superior heat resistance, and the high intensity.

Description

  The present invention relates to a vacuum processing container having a low heat capacity, excellent heat resistance, and high strength.

  Conventionally, in a vacuum processing apparatus, for example, an apparatus for performing a film deposition process on a semiconductor wafer, a boat loaded with a large number of wafers is loaded and sealed, evacuated to a predetermined degree of vacuum, and then a process gas is introduced and heated. The filming process is performed.

  Here, the decompression processing chamber (container) for sealing this kind of wafer is formed into a cylindrical shape by a stone material such as quartz, and a casing provided with a heat insulating material is provided outside the decompression processing chamber ( Patent Document 1).

  The reduced-pressure processing chamber formed in a cylindrical shape with a stone material such as quartz was a uniform integrated structure having a thickness so as to improve heat resistance and to have high strength.

Japanese Patent No. 3056776

  According to the conventional decompression chamber disclosed in Patent Document 1, it is necessary to cover the outside of the decompression chamber with a casing provided with a heat insulating material. Furthermore, since the decompression chamber is an integral structure made of a thick stone such as quartz, the heat capacity becomes very large. When the heat capacity is large, it is difficult to heat and cool. In order to uniformly raise the temperature of the space inside the decompression processing chamber in order to process the wafer, it is necessary to first raise the temperature of the decompression processing chamber itself. However, since the heat capacity is large, it takes time to increase the temperature. In order to increase the temperature rapidly, it is necessary to input a large amount of power, which increases the running cost.

  Further, in order to take out the wafer after the wafer processing is completed, it is necessary to lower the temperature of the decompression processing chamber. Again, because of the large heat capacity, it takes time to lower the temperature. In order to rapidly lower the temperature, a water cooling facility is required, and the running cost increases with the facility cost.

  Further, since it is formed of a stone material such as quartz, the cost is high, and in addition, the maintenance is large, and the management is very complicated.

  In view of such drawbacks, an object of the present invention is to provide a reduced pressure treatment container having a low heat capacity while having excellent heat resistance and high strength.

  The vacuum processing container according to the present invention forms a vacuum heat insulation space between a thin inner container body formed into a cylindrical shape with a metal material and the inner container body, and is formed into a cylindrical shape with the metal material. A thin outer container body formed by forming a large number of rib-like undulations on the outer peripheral surface is joined to form a double structure.

  According to the reduced pressure processing container according to the present invention, the inner container body and the outer container body are formed into a thin cylindrical shape from a metal material, so that they have excellent heat resistance, are easy to carry with a low heat capacity, and are extremely easy to handle. Become.

  Furthermore, since the outer container body is integrally formed with a large number of rib-like undulations formed on the outer peripheral surface thereof, it has high strength and excellent durability.

  In addition, the inner container body and the outer container body are joined to form a double structure, and the internal heat insulation space is in a vacuum, thereby providing a high heat insulation effect and forming a film on a semiconductor wafer under high temperature and reduced pressure. Ideal for use in.

It is a principal part longitudinal cross-sectional view of the pressure reduction processing container of one Example which concerns on this invention. It is a principal part longitudinal cross-sectional view which shows the usage condition of the pressure reduction processing container of the Example which concerns on this invention. It is a principal part longitudinal cross-sectional view which shows the various aspects of the pressure reduction processing container of the other Example which concerns on this invention. It is a principal part longitudinal cross-sectional view which shows the various aspects of the pressure reduction processing container of the further another Example which concerns on this invention. It is sectional drawing which shows another use condition of the pressure reduction processing container of one Example which concerns on this invention.

  A heat insulating space is provided between the inner container body and the thin inner container body formed into a cylindrical shape with a metal material for the purpose of having a low heat capacity, excellent heat resistance, high strength, and being divertable for various applications. This was realized by joining a thin outer container body formed by forming a metal material into a cylindrical shape and forming a large number of rib-like undulations on its outer peripheral surface to form a double structure.

With reference to FIG. 1, the decompression processing container of Example 1 which concerns on this invention is demonstrated.
The shape of the decompression processing container of Example 1 according to the present invention is such that the upper part in the vertical direction is an exhaust port, and the lower part in the vertical direction is a wafer inlet / outlet and a gas inflow port for process gas, etc. Is a substantially cylindrical body with a small hole.

  The decompression processing container is a double-structured container body 17 including an inner container body 11 and an outer container body 17a. A thin inner container body 11 formed in a cylindrical shape with a metal material, particularly stainless steel, and a cylindrical shape formed with a metal material, particularly stainless steel, and a large number of rib-like undulations 15 are formed on the outer peripheral surface thereof. A thin outer container body 17a that forms a vacuum heat insulation space 13 between the inner container body 11 and the inner container body 11 is joined to form a double structure.

  In this example, the thickness of the inner container body 11 is about 1 mm, and the thickness of the outer container body 17a is about 1.5 mm. By making the thickness of the inner and outer container bodies 11 and 17 as thin as 1 mm and 1.5 mm, the material cost can be greatly reduced.

  The outer diameter of the inner container body 11 is φ650 (diameter 650 mm), and the outer diameter of the outer container body 17a is approximately φ730 (diameter 730 mm). The outer diameter of the inner container body 11 is set to φ650, which is the minimum size capable of performing the semiconductor wafer film forming process inside the container. By using this size, the material cost can be reduced and the lightest weight can be realized.

Since the inner container body 11 has an atmospheric pressure on the inner side and a vacuum environment on the outer side, the inner container body 11 receives a force that is pushed from the inner side to the outer side at 1 atm. The inner container body 11 needs to withstand this force. Moreover, since the inner container body 11 becomes high temperature, it is necessary to select a plate thickness in consideration of a decrease in yield strength.
Since the outer container body 17a is in an environment where the inside is vacuum and the outside is atmospheric pressure, the outer container body 17a receives a crushing force from outside to inside at 1 atmosphere. The outer container body 17a needs to withstand this force.

Further, the shape of the undulating portion 15 is a convex shape or a wave shape protruding outward from the outer peripheral surface of the outer container body 17a.
The undulating portion 15 can increase the strength of the outer container body 17a. Therefore, even when the outer container body 17a has a thin thickness of about 1.5 mm, it is possible to maintain sufficient strength.
During the wafer processing, the inner container body 11 becomes high temperature, but the outer container body 17a does not rise so much due to the effect of vacuum insulation. For this reason, large thermal elongation occurs in the inner container body 11, and the outer diameter dimension increases. Since the outer container body 17a has a small thermal elongation, the outer diameter does not increase so much. For this reason, the clearance gap between the inner container body 11 and the outer container body 17a becomes small.

The bottom plate 19 that connects the inner container body 11 and the outer container body 17a needs to be strong enough to withstand this gap change. For this reason, as shown in FIG.1 (b), it is possible to join firmly by the metal material thicker than the inner container body 11 and the outer container body 17a, especially the bottom plate 19 made from stainless steel. However, when the bottom plate 19 is made thick, heat is conducted in a large amount from the inner container body 11 to the outer container body 17a through the bottom plate 19, and the heat insulation effect is significantly reduced.
For this reason, as shown in FIG. 1 (a), the bottom plate 19 has a thickness less than the thickness of the inner container body 11, and absorbs a change in the gap between the inner container body 11 and the outer container body 17a. It is desirable to have a structure using a bottom plate 19 made of stainless steel, for example, having a U-shaped cross section.

A process of performing a thermal oxidation process on a workpiece using the reduced pressure processing container according to the present invention will be described with reference to FIG.
First, an evacuation pump (not shown) is installed in the upper port of the decompression processing vessel, and an inflow tube (not shown) for letting process gas flow into a part of the lower opening O, a vacuum pump (not shown), An air cooling port (not shown), a gate valve (not shown), etc. are installed.

  Next, after carrying the workpiece W into the reduced pressure processing container, the inside of the reduced pressure processing container is evacuated to remove unnecessary gas and heated by a heating mechanism (not shown) disposed in the reduced pressure processing container. Then, by causing the process gas to flow into the inner container body 11, thermal oxidation is performed on the workpiece W on the work table T carried into the reduced pressure processing container.

At this time, since the heat capacity of the inner container body 11 of the reduced pressure processing container according to the present invention is small, the temperature in the reduced pressure processing container becomes uniform in a short time. At the same time, since the temperature in the reduced pressure processing container is also maintained by the vacuum insulation, the wafer processing operation can be reliably performed.
Moreover, the temperature of the wafer and the inner container body 11 of the reduced pressure processing container can be lowered in a short time by introducing the cooling gas into the reduced pressure processing container after completion of the wafer processing. The cooling gas used here must be a gas that does not affect the wafer. For example, an inert gas such as argon may be used.

FIG. 3 shows various embodiments of the bottom plate 19 as a second embodiment.
The bottom plate 19 shown in FIG. 3 (a) is directed so that the bottom plate 19 having a U-shaped cross section equal to or less than the thickness of the inner container body 11 faces the gap between the inner container body 11 and the outer container body 17a. This is an example in which it is arranged as a convex. The bottom plate 19 shown in FIG. 3B has the other ends of the bottom plate piece 19a and the bottom plate piece 19b joined at one end, the bottom plate piece 19a on the side of the lower end of the outer container body 17a, and the bottom plate piece 19b on the inner container body. 11 It joins to the lower end part side. The bottom plate 19 shown in FIG. 3C is formed by joining the other end of the bottom plate 19 with one end joined to the lower end of the inner container body 11 to the side surface of the lower end of the outer container body 17a. The bottom plate 19 shown in FIG. 3D is formed by joining the other end of the bottom plate 19 whose one end is joined to the lower end portion of the outer container body 17a to the side surface of the lower end portion of the inner container body 11.

FIG. 4 shows another embodiment of the outer container body 17a as the third embodiment.
In this embodiment, the outer container body 17a has a ceiling portion 17b that is convex toward the inside of the outer container body 17a. The outer container body 17a and the ceiling portion 17b are formed separately and their edges are joined to each other. Therefore, it can manufacture efficiently compared with the integral outer container body 17a including a ceiling part.

FIG. 5 shows another example of use of the vacuum processing container according to the present invention.
In this example, after the workpiece W is loaded into the reduced pressure processing container, it is heated by the heating mechanism H arranged outside the reduced pressure processing container, and the process gas is introduced into the container to be loaded into the reduced pressure processing container. The workpiece W on the work table T is subjected to thermal oxidation, and the configuration and operation of the decompression processing container are the same as those in the first embodiment.

  In this example, the heat insulating space 13 formed between the inner container body 11 and the outer container body 17a is not a vacuum, but is a gas layer such as argon or xenon having a lower thermal conductivity than air.

Even if the heat insulating space 13 is a gas layer, the same high heat insulating effect as that obtained when a vacuum is applied can be obtained.
For this reason, it becomes possible to reduce work efficiency and work cost compared with making the heat insulation space 13 into a vacuum.

  In both examples, the shape of the inner container body 11 and the outer container body 17a is such that the lower part is largely open and the upper part has small holes, but the upper and lower parts may have the same diameter. It is self-evident to use a combination of the diameters.

  Moreover, although the thickness of the inner container body 11 is about 1 mm and the thickness of the outer container body 17a is about 1.5 mm, it is not necessarily limited to this thickness.

  In addition, the shape of the undulating portion 15 of the outer container body 17a is a convex shape or a corrugated shape protruding outward from the outer peripheral surface of the outer container body 17a, but it is obvious that the shape is a saw blade shape, a spiral shape, or other shapes. .

  Although the embodiment of the present invention has been described above, the present invention is not limited to the embodiment 1 to the embodiment 5 and can of course be implemented in various modes without departing from the gist of the present invention. is there.

  The decompression processing container according to the present invention is not only used for thermal oxidation processing of a workpiece, but also for transferring a semiconductor wafer film, other processing steps, products, solvents and the like for transfer in a clean room. Is also applicable.

17 Container body 17a Outer container body 11 Inner container body 13 Thermal insulation space 15 Unraveling portion 19 Bottom plate T Work table W Workpiece H Heating mechanism

Claims (5)

  A vacuum heat insulation space is formed between the thin inner container body formed into a cylindrical shape with a metal material and the inner container body, and is formed into a cylindrical shape with a metal material, and rib-like undulations are formed on the outer peripheral surface thereof. A reduced-pressure treatment container characterized by joining a thin outer container body formed in large numbers to form a double structure.   The decompression processing container according to claim 1, wherein the inner container body has a wall thickness equal to or less than that of the outer container body.   The decompression processing container according to claim 1 or 2, wherein the bottom plate that joins the inner container body and the outer container body has a structure that absorbs a change in a gap between the inner container body and the outer container body.   The decompression processing container according to any one of claims 1 to 3, wherein the bottom plate 19 uses a U-shaped member having a thickness equal to or less than a thickness of the inner container body.   The vacuum processing container according to any one of claims 1 to 4, wherein the metal material of the outer container body is stainless steel.

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