JP3617681B2 - Gas supply system for portable sealed containers - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a gas supply system for a portable sealed container for replacing the inside of a portable sealed container used in a clean room with an inert gas.
[0002]
[Prior art]
For example, semiconductor manufacturing is performed in a clean room where the internal atmosphere is cleaned, but transfer between processes in the clean room is possible using a wafer cassette containing the semiconductor wafer in order to prevent dust from adhering to the semiconductor wafer. It is stored in a portable sealed container. Furthermore, in recent years, in order to prevent the growth of an oxide film due to natural oxidation of a semiconductor wafer, the internal atmosphere of the sealed container is replaced with an inert gas such as nitrogen N ₂ gas.
[0003]
As described above, in recent years, a wafer cassette is placed in a sealed container filled with nitrogen N ₂ gas to be transported and stored. However, the concentration of nitrogen N ₂ gas in the sealed container is determined during transport standby or storage. In such a case, conventionally, a sealed container in which the concentration of nitrogen N ₂ gas is reduced is transported to a gas purge station provided in the clean room, where it is purged again. Since it was later returned to its original location, there was a problem that wasteful transport had to be performed and the storage of the sealed container was complicated.
[0004]
[Problems to be solved by the invention]
In order to solve this problem, the inventor of the present invention has proposed a portable closed container gas supply system described in Japanese Patent Application No. 4-128850. This portable closed container gas supply system includes a purge box having a space therein, an elevator that is fitted into the opening of the purge box and seals the opening from the inside of the box, and opens inside the purge box. A sealed container with a lock mechanism is placed with the supply gas pipe and the exhaust gas pipe as main parts, with the opening of the purge box sealed. When the concentration of the inert gas (for example, nitrogen N ₂ gas) in the sealed container decreases, the lock mechanism of the container is released and the lid is slightly displaced toward the lifting platform side, so that nitrogen N is supplied from the supply gas. ₂ gas flows into the interior space of the purge box and into the container, and these internal gases are expelled to the outside through the exhaust pipe, thereby replacing the nitrogen N ₂ gas in the container with a high-concentration gas. After purging), the lid is locked again by the locking mechanism to seal the inside of the container.
[0005]
However, in the gas supply system of a portable closed container of the prior art, even if the inside of the sealed container is replaced with high-concentration nitrogen N ₂ gas and the lid is locked and stored in a sealed state, There is a problem that adsorbed substances (impurities) start to be released into the container from a mechanism portion such as a mechanism, and the moisture and oxygen concentrations are increased to contaminate the semiconductor wafer.
[0006]
In order to solve this problem, it is conceivable to continuously supply nitrogen N ₂ gas from the supply gas pipe. However, the space of the purge box other than the container is large, and in order to reduce the unnecessary gas concentration, replacement is necessary. A large amount of pure nitrogen N ₂ gas is required, the unnecessary gas cannot be easily exhausted, it takes a long time to replace the nitrogen N ₂ gas, and the gas supply system is enlarged for the purge box, which is uneconomical. It becomes.
[0007]
The present invention has been made to solve this problem, and is a portable sealed container that can reduce contamination of semiconductor wafers in a sealed container by constantly flowing a certain amount of replacement gas economically. An object is to provide a gas supply system.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, in the gas supply system for a portable sealed container according to the present invention, a portable sealed container that contains a semiconductor wafer and is sealed in an inert gas atmosphere; In the gas supply system of a portable closed container comprising a gas supply device for supplying an active gas, the closed container has the inert gas in a direction opposite to each other through a plurality of gas passages communicating between the inside and the outside. A one-way valve that allows the flow of the gas, and the gas supply device can be connected to and separated from each other corresponding to each gas passage, and supplies an inert gas through one of the one-way valves, when the unnecessary gas in the sealed container via the other of said one-way valve forms a gas flow path to be discharged, stored by placing the friendly transportable sealed container, the sealed co During storage at all times of the containers, continuing to supply the inert gas to a predetermined pressure, and the inside movable transportable sealed container is configured to replace in the inert gas.
[0009]
[Action]
Thus, in the gas supply system of the portable closed container of the present invention, each gas passage of the closed container is connected to each gas flow path of the gas supply device, and one gas flow path is passed through the one-way valve. Inert gas can be supplied into the sealed container, and unnecessary gas (air, water, etc.) in the sealed container can be exhausted to the outside from the other gas flow path via the one-way valve. By simply connecting the gas passage to the gas flow path of the gas supply device, the inert gas can be replaced very easily and in a short time.
[0010]
Further, when a portable sealed container is taken out from the gas supply device and transported, unnecessary gas (air / water) from the gas passage into the container is closed by closing the one-way valve provided in each gas passage. Etc.) can be prevented.
[0011]
【Example】
Hereinafter, a gas supply system for a portable sealed container according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a configuration of a gas supply system for a portable sealed container in the present embodiment, and FIGS. 2A and 2B are views of a one-way valve of a gas supply system for a portable sealed container in the present embodiment. It is a principal part enlarged view which shows a structure.
[0012]
In FIG. 1, reference numeral 1 denotes a gas supply system for a portable sealed container disposed at a predetermined location in a clean room, and includes a gas supply device 5 and a portable sealed container 10 as main parts. Reference numeral 11 denotes a main body of a sealed container (POD) 10, and a flange 13 is provided in the opening 12. Further, a lid 15 is fitted into the opening 12 of the sealed container 10 via an annular sealing material 14, and the lid lock mechanism 16 provided on the lid 15 is locked to lock the sealed container 10. The internal space A is sealed. In addition, the lid 15 is provided with gas passage pipes 20 and 21 that communicate the internal space A of the sealed container 10 with the outside at a predetermined interval in the circumferential direction having a predetermined radius (with a phase of 180 degrees). Is provided. Each gas passage pipe 20, 21 extends through the lid 15 in parallel with each other (extends through the thickness of the lid 15), and includes a one-way valve (check valve) inside thereof. Valves) 30 and 31 are arranged, respectively. Reference numeral 16 denotes a handle provided outside the sealed container 10. Reference numeral 17 denotes a wafer cassette containing the semiconductor wafer W, which is placed on the lid 15 in the internal space A of the sealed container 10 without blocking the gas passage tubes 20 and 21.
[0013]
As shown in FIG. 2A, a stepped hole 22 in which a small diameter hole 22A, a large diameter hole 22B, and a small diameter hole 22C are successively formed from the lid 15 toward the end side is formed in the gas passage pipe 20. The spherical valve body 30B is seated with the inclined surface connecting the large diameter hole 22B and the small diameter hole 22C as the valve seat 30A of the one-way valve 30. The spherical valve body 31B of the one-way valve 30 is urged against the valve seat 30A by a valve spring 23 stretched between the step portion 22a of the large-diameter hole 22B. Thereby, the one-way valve 30 allows the flow of the inert gas (nitrogen N ₂ gas) from the outside of the sealed container 10 into the internal space A and prevents the reverse. Further, as shown in FIG. 2B, the gas passage pipe 21 has a stepped hole 24 in which a small diameter hole 24A, a large diameter hole 24B, and a small diameter hole 24C are successively connected from the lid 15 toward the end side. The spherical valve body 31B is seated on the inclined surface connecting the large diameter hole 24B and the small diameter hole 24A as the valve seat 31A of the one-way valve 31. The spherical valve body 31B of the one-way valve 31 is urged against the valve seat 31A by a valve spring 25 stretched between the step portion 31a of the large-diameter hole 31B. Thereby, the one-way valve 31 allows the flow of the nitrogen gas N ₂ gas from the internal space A of the sealed container 10 to the outside and prevents the reverse.
[0014]
Reference numeral 40 denotes a supply base of the gas supply device 5, and the upper surface 40a is connected to the connector at a predetermined interval in the circumferential direction having the same radius as the gas supply pipes 20 and 21 (with a phase of 180 degrees). Tubes 41 and 42 protrude, and annular seal members 41A and 42A are provided at the ends of the connector tubes 41 and 42, respectively. The connector pipe 42 generates an inert gas (for example, nitrogen N ₂ gas) via a flue gas pipe 43 to a processing apparatus (not shown), and the connector pipe 42 via a gas supply pipe 44 and an on-off valve 45. The gas supply flow path 50 is formed by the connector pipe 42 and the exhaust gas pipe 43, and the gas supply flow path 51 is formed by the connector pipe 41, the gas supply pipe 44, and the on-off valve 45. ing. Reference numeral 52 denotes a detection sensor that detects whether the sealed container 10 is securely installed on the supply base 40 of the gas supply apparatus 1. 53 is a container guide standing on the supply stand 40.
[0015]
Then, in order to replace the inside space A of the sealed container 10 with nitrogen N ₂ gas, the gas passage pipes 20 and 21 are respectively matched with the connector pipes 41 and 42 by an operator in the clean room or automatic conveyance (not shown). When placed on the supply base 40 of the gas supply device 5, the gas passage tube 20 and the connector tube 41, and the gas passage tube 21 and the connector tube 42 are connected in an airtight manner via the annular seal members 41A and 42A, respectively. The detection sensor 50 detects whether or not the sealed container 10 is reliably placed on the supply base 40. After each gas passage pipe 20, 21 is connected to each of the connector pipes 41, 42, the gas supply source 46 is operated, and when the on-off valve 45 is opened, the nitrogen N ₂ produced by the gas supply source 46 The gas is supplied to the connector pipe 41 via the on-off valve 45-supply gas pipe 44, and the pressure of the supplied nitrogen N ₂ gas acts on the spherical valve body 30B of the one-way valve 30, so this spherical valve body 30 Is separated from the valve seat 30A against the spring force of the valve spring 23, and the one-way valve 30 is opened. Thereby, the nitrogen N ₂ gas passes through the one-way valve 30 and is supplied into the internal space A of the sealed container 10 via the gas passage pipe 20.
[0016]
In this case, the internal space A is filled with nitrogen N ₂ gas of the sealed container 10, the nitrogen N ₂ gas in the space A becomes a predetermined pressure, the spherical valve body 31B of the valve spring 25 of the one-way valve 31 spring The one-way valve 31 opens from the valve seat 31A against the force. Thereby, unnecessary gas (air, water, etc.) in the internal space A of the container 10 passes through the gas passage pipe 21, the connector pipe 42, the one-way valve 31, and the exhaust gas pipe 43. ). Then, during a predetermined time, nitrogen N ₂ gas is supplied from the gas passage tube 20 into the sealed container 10 and unnecessary gas (air, moisture, etc.) in the sealed container 10 is exhausted from the gas passage tube 21 to the outside. As a result, the nitrogen N ₂ gas in the internal space A of the sealed container 10 is replaced, and the concentration of unnecessary gas (air, water, etc.) is reduced to make the environment suitable for storage of the semiconductor wafer W.
[0017]
Next, when the replacement of the nitrogen N ₂ gas is completed and the operation of the gas supply source 46 is stopped and the on-off valve 45 is closed, the spherical valve 30B in the one-way 30 is moved by the spring force of the valve spring 23. When the one-way valve 30 is seated on the valve seat 30A and the pressure in the inner space A of the sealed container 10 becomes a constant value (the spring force of the valve spring 25 is the same pressure), the one-way valve 31 is closed. The spherical valve body 31B is seated on the valve seat 31A by the spring force of the valve spring 25, the one-way valve 31 is closed, and the sealed container 10 is sealed. Then, the sealed container 10 is taken out from the supply table 40 and transported to a predetermined destination by an operator in the clean room or by automatic transport (not shown).
[0018]
Further, when the sealed container 10 is placed on the gas supply device 5 and stored, the gas supply source 46 is continuously operated, the one-way valves 30 and 31 are opened, and the nitrogen is always kept during the storage. The N ₂ gas continues to be supplied into the sealed container 10 through the gas supply pipe 44 -connector pipe 41 -gas passage pipe 20 and one-way valve 30, and the gas passage pipe 21 -one-way valve 31 -connector pipe 42 and exhaust gas Through the pipe 43, unnecessary gas (air, moisture, etc.) is sequentially exhausted outside the sealed container 10 into the sealed container 10, and the container inner surface is transferred until the sealed container 10 is transported to a predetermined destination. Unnecessary gases (moisture and air) that start to be released into the sealed container 10 from the mechanism portion such as the lock mechanism 16 are sequentially exhausted to the outside of the sealed container 10 to prevent the semiconductor wafer W from being contaminated.
[0019]
In the gas supply system of the portable sealed container in the present embodiment, the one-way valves 30 and 31 arranged in the gas supply pipes 20 and 21 are not limited to this, and FIG. And as shown in FIG.3 (b). That is, in the gas passage pipe 20, as shown in FIG. 3A, the large-diameter hole portion 22B is divided into two spaces B and C by a partition member 30C serving as a valve seat of the one-way valve 30, The partition member 30C in the space B on the small-diameter hole 22A side is provided with an umbrella-shaped valve body 55 formed of plastic or rubber material constituting the one-way valve 30, and the umbrella-shaped section 55A of the umbrella-shaped valve body 55 A plurality of through holes 56 communicating with the sealed space D formed between the partition member 30C and the umbrella-shaped portion 55A of the umbrella-shaped valve body 55 are partitioned by nitrogen N ₂ gas from the small-diameter hole portion 22C. It leaves | separates from the member 30C and makes it a valve opening state. Further, in the gas passage pipe 21, as shown in FIG. 3B, the large-diameter hole portion 24B is partitioned into two spaces E and F by a partition member 31C serving as a valve seat of the one-way valve 31, The partition member 31C of the space F on the small-diameter hole 24C side is provided with an umbrella-shaped valve body 60 formed of plastic or rubber constituting the one-way valve 31, and the umbrella-shaped portion 60A of the umbrella-shaped valve body 60 A plurality of through holes 61 communicating with the sealed space G formed between the partition member 31C and the umbrella-shaped portion 60A of the umbrella-shaped valve body 60 is partitioned by nitrogen N ₂ gas from the small-diameter hole portion 24A. It is separated from the member 31C to be in a valve open state.
[0020]
Moreover, in the gas supply system of the portable sealed container in the present embodiment, the gas passages 20 and 21 are placed on the connector pipes 41 and 42, whereby the gas passages are provided via the annular sealing materials 41A and 42A. The pipes 20 and 21 and the connector pipes 41 and 42 are connected in an airtight manner. However, the present invention is not limited to this, and as shown in FIG. A small-diameter portion 20A that can be fitted into the recess 65 at the distal end portion of each gas passage pipe 20, 21 while forming the location 65 and disposing the annular sealing material 66 on the inner peripheral surface 65a of the recess 65. 21A is formed, and the small diameter portions 20A and 21A are fitted into the recesses 65 of the connector pipes 41 and 42, respectively, so that the gas passage pipes 20 and 21 and the connector pipes are connected via the annular sealing material 66. 41, 42 And it may be one which is adapted to connect in an airtight manner.
[0021]
Furthermore, the number of pipes of the gas passage pipes 20 and 21 and the connector pipes 41 and 42 provided in the sealed container 10 and the gas supply device 5 is not limited to this.
[0022]
【The invention's effect】
Thus, according to the gas supply system of the portable closed container of the present invention, each gas passage of the closed container is connected to each gas flow path of the gas supply device, and a one-way valve is connected from one gas flow path. The inert gas can be supplied into the sealed container through the one-way valve, and unnecessary gas (air, water, etc.) in the sealed container can be exhausted from the other gas flow path through the one-way valve. A small amount of inert gas is required to reduce the concentration of unnecessary gas, and the unnecessary gas can be easily exhausted. Also, it is economical when supplying inert gas into a sealed container at all times. In addition, the contamination of the semiconductor wafer can be reduced, and the inert gas can be replaced very easily and in a short time by simply connecting each gas passage of the sealed container to the gas flow path of the gas supply device. so That.
[0023]
Further, when a portable sealed container is taken out from the gas supply device and transported, unnecessary gas (air / water) from the gas passage into the container is closed by closing the one-way valve provided in each gas passage. Etc.) can be prevented, so that the semiconductor wafer in the sealed container can be prevented from being contaminated.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a configuration of a gas supply system of a portable sealed container in an embodiment of the present invention.
FIGS. 2A and 2B are enlarged views of a main part showing a configuration of a one-way valve of a gas supply system for a portable sealed container in an embodiment of the present invention.
FIGS. 3A and 3B are main part enlarged views showing the configuration of a modification of the one-way valve of the gas supply system of the portable sealed container in the embodiment of the present invention. FIGS.
FIG. 4 is a main part enlarged view showing a modified example of the connection structure between the gas passage pipe and the connector pipe of the gas supply system of the portable sealed container in the embodiment of the present invention.
[Explanation of symbols]
5 Gas supply device 10 Portable sealed container 20, 21 Gas passage pipe 30, 31 One-way valve 50, 51 Gas flow path

Claims (1)

A gas supply for a portable sealed container comprising a portable sealed container that contains a semiconductor wafer and is sealed in an inert gas atmosphere, and a gas supply device that supplies an inert gas into the portable sealed container. In the system,
The sealed container is provided with a one-way valve that allows the flow of the inert gas in a direction opposite to each other in a plurality of gas passages that communicate between the inside and the outside, and the gas supply device includes each gas A gas flow path corresponding to a passage, supplying an inert gas through one of the one-way valves, and discharging unnecessary gas in the sealed container through the other one-way valve When the portable sealed container is placed and stored, the inert gas is continuously supplied so as to be at a predetermined pressure during the storage of the sealed container, and the inside of the portable sealed container is A gas supply system for a portable sealed container, wherein the gas is replaced with the inert gas.

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