JPH11147051A - Method and device for cleaning storage space - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning method and a device thereof for a storage space for preventing effectively the pollution for a base or a base plate. SOLUTION: In a cleaning device for a storage space provided with a storage space B for storing a base 2 on a base plate 2 and a cleaning means A using ultraviolet rays 5 as a light source for introducing clean air into the storage space, a partition plate 14 for accelerating the flowing generated by the convection of gas and a granular material charging and collecting section by using photoelectrons 11 to be used as a cleaning means and a means of removing gaseous pollutants by using a photocatalyst 4, or a means of one kind or more out of antistatic sections utilizing ultraviolet emission or a means of combining said removing sections with a section of removing gaseous pollutants utilizing ion exchange vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the cleaning of a storage space, and in particular, stores raw materials, semi-finished products, base materials and substrates of products in advanced industries such as semiconductors, liquid crystal and precision machine industries.
The present invention relates to a method and an apparatus for cleaning a storage space for preventing contamination of the base material and the substrate surface with fine particles and gaseous substances.

[0002]

2. Description of the Related Art Conventional air cleaning in a clean room will be described with reference to FIG. 9 by taking air cleaning in a semiconductor manufacturing plant as an example. In FIG. 9, first, coarse particles are removed from the outside air 21 by a pre-filter 22, then air-conditioned by an air conditioner 23, and dust is removed by a medium-performance filter 24. Next, fine particles are removed by a HEPA filter (high-performance filter) 26 installed on the ceiling of the clean room 25, and the clean room 25 is maintained in a class of 100 to 1,000 ("cleaning design" p.11). ~ 24, Summer 198
8). 27 _-1 and 27 _-2 indicate fans, and arrows indicate the flow of air. Since the conventional air cleaning in a clean room is aimed at removing fine particles, it has been configured as shown in FIG. Such a configuration is effective for removing fine particles, but is not effective for removing gaseous harmful components.

[0003] In the future, in the semiconductor industry, the quality and precision of products will be increasingly increased, and gaseous substances will be involved as contaminants. In other words, removal of fine particles has been sufficient in the past, but now gaseous substances (gaseous harmful components)
Control becomes important. In the conventional clean room filter shown in FIG. 9, only the fine particles are removed, and gaseous harmful components from the outside air are introduced into the clean room without being removed. That is, in a clean room, fine particles (particulate matter) and conventional dust filters (eg, HEPA, UL)
PA filters) are not trapped and removed, but are introduced into the clean room. Exhaust gas from automobiles, hydrocarbons (HC) caused by degassing from polymer resin products widely used as consumer products, etc. , NOx, SOx, KC
1, gaseous substances such as acidic gas such as HF, and basic (alkaline) gas such as NH ₃ and amine are problematic as gaseous harmful components.

Among them, H.I. C is a gaseous harmful component and must be removed because it has a very low concentration in normal air (indoor air and outside air). Recently, degassing from polymer resins of clean room components and tools (wafers, carrier boxes) has been described in H.H. It is a problem as a C source. (Japan Machinery Federation, 1994 report, March 1995, pp. 41-4
9, 1995). These gaseous substances also pose a problem when they are generated during the operation in the clean room. That is,
In a normal clean room as a cause of the gaseous substances,
The gaseous substances generated in the clean room are added to the gaseous substances introduced from the outside air (the gaseous substances in the outside air are introduced because the gaseous substances cannot be removed by the filter in the clean room). The gaseous substances in the clean room have a higher concentration than the outside air, and contaminate the wafer base material and the substrate.

That is, if the above-mentioned contaminants (fine particles, gaseous harmful components) adhere to the substrate surface of a wafer, a semi-finished product, or a product, the fine particles cause a disconnection or short circuit of a circuit (pattern) on the substrate surface to cause a defect. Cause. Further, as a gaseous substance, When C adheres to the wafer (substrate) surface, it causes an increase in the contact angle. C affects the affinity (fit-in) between the substrate and the resist. When the affinity deteriorates, the film thickness of the resist is adversely affected, or the adhesiveness between the substrate and the resist is adversely affected (Air Purification, Vol. 33, No. 1, pp. 16-21, 1995). S
Ox causes oxide film insulation failure. NH ₃
Causes formation of ammonium salts, etc., causing clouding (defective resolution) on wafers (Realise, latest technology course, data collection, semiconductor process seminar, October 1996
29, p. 15-25, 1996). For these reasons, these gaseous contaminants reduce the productivity (yield) of semiconductor products.

In particular, since the above-mentioned gaseous substances as gaseous harmful components are used by increasing the circulation of the clean room air due to the above-mentioned generation and recently from the viewpoint of energy saving, the concentration of the gaseous substances in the clean room is reduced. Concentrated,
It has a considerably higher concentration than the outside air, adheres to a substrate or a substrate, and contaminates the surface. The degree of this contamination can be represented by the contact angle between the substrate and the substrate. A base material or a substrate having a large contact angle, even when formed on the surface thereof, has a low adhesion strength of the film (poor adaptability), leading to a decrease in yield. Here, the contact angle is a contact angle of wetting by water, and indicates a degree of contamination of the substrate surface. That is, when a hydrophobic (oil-based) contaminant adheres to the substrate surface, the surface repels water and becomes hard to wet. Then, the contact angle between the substrate surface and the water droplet increases. Therefore, the contamination degree is high when the contact angle is large, and low when the contact angle is small.

In particular, since air in a clean room is recently circulated and used in terms of energy saving, gaseous harmful components in the clean room gradually increase, and contaminate the base material and the substrate. Against such a background, the present inventors, in the enclosed space exemplified in the following (1) to (3), photoelectrons,
Cleaning methods and apparatuses using photocatalysts and ion exchange fibers have been proposed. (1) With respect to contamination of fine particles (particulate matter), a method and apparatus for charging fine particles using photoelectrons and collecting / removing the charged fine particles using an electrode material or the like (for example, Japanese Patent Publication No. H8-211)
No., JP-B-7-121369). (2) A method and an apparatus for removing contamination of gaseous substances using a photocatalyst or ion exchange fiber (for example, Japanese Patent Application Laid-Open No.
168722, JP-A-9-205046). (3) A method and an apparatus for simultaneously removing gaseous substances of fine particles (JP-A-1-266864, JP-A-7-57981, and JP-A-8-261536). These methods and devices are effective depending on the type of application, the shape and structure of the device, and the method of storing the substrate and substrate in the space. Depending on the method, there was room for improvement.

Next, regarding this improvement, the prevention of organic gas already proposed by the present inventor (Japanese Patent Laid-Open No. 9-16872).
No. 2) will be described as an example. FIG. 10 shows the wafer stocker 1
FIG. The stocker 1 stores a wafer 2. The photocatalyst 4 is installed on a part of the wall material 3 of the stocker 1, and the photocatalyst 4 is irradiated with ultraviolet rays from an ultraviolet lamp 5. Since the stocker 1 uses a packing material (plastic) and a sealing material for its components, if it is attached on the wafer, it will increase the contact angle.
A very small amount of organic gas 6 is generated, but is treated by the photocatalyst 4 and converted into a detoxifying gas 7. Here, reference numeral 8 denotes a light shielding material for preventing ultraviolet rays from the ultraviolet lamp 5 from being irradiated on the wafer 2 (a semi-finished product which is sensitive to ultraviolet rays).

Reference numeral 9 denotes a reflecting surface for efficiently irradiating the photocatalyst 4 with ultraviolet rays from the ultraviolet lamp 5. Here, the organic gas 6 is generated by irradiation of the photocatalyst 4 of the ultraviolet lamp 5 with the gas flow 10 ₋₁ to 10 ₋ caused by a slight temperature difference between the upper and lower portions of the processing space A of the organic gas 6 by the photocatalyst 4. _{By 5} , it is sent to the processing space A and converted into a detoxifying gas. On the other hand, in such a configuration,
In addition to the above airflow, 10 _-6 and 10 _-7 airflows are generated, and the airflow is not used for processing (moving) the organic gas 6 and is useless. Therefore, there is room for improvement so that the air flows 10 _-6 and 10 _-7 do not occur in the cleaning with such a configuration.

In the advanced industries, commercialization and refinement of products are progressing year by year, while efficient production (cost reduction) is required. Accordingly, Si
The size of wafers and glass substrates is increasing. That is, when the size of the substrate is increased, the substrate is often placed horizontally as shown in FIG. 10 (operability is poor when a large substrate is placed upright). This is important for effectively cleaning the storage space using ultraviolet rays. In addition, in the future advanced industry, as described above, cost reduction is required,
Local cleaning (mini-environment) is spreading rapidly. However, in local cleaning, the use of polymer materials has increased, and it has been expected that a system for effectively preventing contamination due to the generation of organic gas from these materials will appear.

[0011]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above-mentioned prior art, and has as its object to provide a method and an apparatus for cleaning a storage space which can effectively prevent contamination of a substrate or a substrate. Make it an issue.

[0012]

According to the present invention, there is provided a method for cleaning a storage space for storing a substrate or a substrate having a cleaning means using ultraviolet light as a light source. A guiding means for promoting a convective flow of gas in the space inside the space. In the method, the cleaning means is at least one of charging and collecting particulate matter by photoelectrons, removing gaseous pollutants by a photocatalyst, or removing electricity by ultraviolet irradiation, or
These can be used in combination with the removal of gaseous pollutants by ion exchange fibers, and a partition plate can be used as the guiding means. In the present invention,
In a storage space cleaning device having a storage space in which a base material or a substrate is stored, and a cleaning unit using ultraviolet light as a light source to send a clean gas to the storage space, the gas in the space is stored in the storage space. A partition plate for promoting the flow by convection; and one of the purifying means for charging and collecting particulate matter by photoelectrons, removing gaseous pollutants by photocatalyst, or removing electricity by ultraviolet irradiation. More than one kind of means, or a means combining these with a portion for removing gaseous pollutants by ion exchange fibers is provided.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention has been made based on the following five findings. (1) The use of ultraviolet rays for cleaning a closed space in which a substrate or a substrate is stored has an advantage that it can be effectively cleaned without using a fan. This is because the problem of cleaning using a conventional fan, that is, the problem of generation of gaseous pollutants and particulate matter from the fan is not of this type, so that an ultra-clean space can be effectively obtained. . In this method, a gas in an enclosed space flows due to a slight temperature difference caused by ultraviolet irradiation, and contaminants in the space are sequentially sent to a contaminant processing space to be processed. (1) Aerosol Research, Vol. 8, No. 4, p. 315-324, 1
993, 2) Proceedings of the 12th ISCC in Yo
kohama, p. 117-122, 1994, 3) JP-A-9
(2) In the above-mentioned cleaning, the base material and the substrate are housed in a closed space, and the generated air flow (the flow of the cleaning gas) is controlled by the base material and the cleaning method. The ability to pass through the substrate is an important point for effective cleaning. That is, it can be said that a problem in effectively performing cleaning is not to generate a flow (bypass) that does not contribute to cleaning of the base material and the substrate in the closed space.

(3) The above-mentioned problem becomes even more important because the size of wafers and glass substrates will be increased in the future, and the conventional vertical setting will be changed to horizontal setting. That is, the air flow flows from the top to the bottom in the conventional vertical setting, so that it is effectively cleaned if left to natural phenomena.
On the other hand, in the case of the horizontal installation, since the airflow depends on the temperature difference and the resistance, it is difficult to obtain the horizontal airflow uniformly by leaving it to natural phenomena. (4) The above problem can be solved by providing a partition plate (obstruction plate, baffle plate) for guiding (effectively utilizing) the flow into the storage space for the base material and the substrate. (5) The method for cleaning the enclosed space can be suitably performed by using a method using a photoelectron, a method using a photocatalyst, a method for removing electricity by irradiating ultraviolet rays, and a method using them in combination with an ion exchange fiber.

Next, the configuration of the present invention will be described in detail. A partition plate (obstruction plate, baffle plate) as an airflow guiding means is used to effectively utilize a flow of air generated by ultraviolet irradiation used for the cleaning means, and to prevent contamination of the base material and the substrate.
This is for sending onto (in the vicinity of) a substrate or a substrate, and an appropriate material and shape can be used. The shape, position, and number of the partition plates are determined by conducting preliminary tests at one or more places depending on the type and shape of the device, the shape and size of the substrate and substrate, the position of the ultraviolet light source, the required performance, etc. be able to. In general, it may be installed at one or more locations above and / or in the center of the cleaning space so that the airflow is sent to the substrate or substrate.

Next, the structure of each cleaning means will be described. (1) Photoelectron method The photoelectron method is effective for removing particulate matter (fine particles) (the above-mentioned 1) aerosol research, and 2) Procee
dings of the 12th ISCC in Yokohama). As the method using photoelectrons, those already proposed by the present inventors can be appropriately used (for example, Japanese Patent Publication No.
-74909, JP-B8-211, JP-B7-12
1369, JP-B-8-22393). The photoelectron emitting material used for emitting photoelectrons may be any material that emits photoelectrons by irradiating ultraviolet rays, and the smaller the photoelectric work function, the better. Ba, Sr, Ca, Y, Gd, La, Ce, N
d, Th, Pr, Be, Zr, Fe, Ni, Zn, C
u, Ag, Pt, Cd, Pb, Al, C, Mg, Au,
In, Bi, Nb, Si, Ti, Ta, U, B, Eu,
Any of Sn, P, and W, or a compound, an alloy, or a mixture thereof is preferable, and these are used alone or in combination of two or more. As the composite material, a physical composite material such as amalgam can be used.

For example, compounds include oxides, borides and carbides, and oxides include BaO, SrO, and Ca.
O, Y ₂ O ₅ , Gd ₂ O ₃ , Nd ₂ O ₃ , ThO ₂ , Z
rO ₂ , Fe ₂ O ₃ , ZnO, CuO, Ag ₂ O, La
₂ O ₃ , PtO, PbO, Al ₂ O ₃ , MgO, In ₂
O ₃ , BiO, NbO, BeO, etc., and borides include YB ₆ , GdB ₆ , LaB ₅ , NdB ₆ , Ce
_{B 6, EuB 6, PrB 6} , ZrB 2 include, as a further carbide UC, ZrC, TaC, TiC, Nb
C and WC. In addition, brass, bronze,
Phosphor bronze, alloy of Ag and Mg (Mg is 2 to 20 wt.
%), An alloy of Cu and Be (Be is 1 to 10 wt%), an alloy of Ba and Al, and an alloy of Ag and Mg, an alloy of Cu and Be, and an alloy of Ba and Al. Alloys are preferred. The oxide can also be obtained by heating only the metal surface in air or oxidizing it with a chemical.

As still another method, it is possible to form an oxide layer on the surface by heating before use to obtain an oxide layer that is stable for a long time. As an example of this, an oxide film can be formed on the surface of an alloy of Mg and Ag in water vapor at a temperature of 300 to 400 ° C., and this oxide thin film is stable for a long time. . These substances can be used in bulk (solid or plate) or added to an appropriate base material (support) (Japanese Patent Application Laid-Open No. Hei 3-1086).
No. 98). For example, it can be added to the surface of or near the surface of the ultraviolet ray transmitting substance (Japanese Patent Publication No. 7-93098). Any method can be used as long as photoelectrons are emitted by irradiation of ultraviolet rays. For example, a method of coating and using on a glass plate, a method of embedding near the surface of a plate-like material as another example, and a method of adding another material on a plate-like material and further coating it on a plate-like material And a method using a mixture of an ultraviolet-transmissive substance and a substance that emits photoelectrons. In addition, a method of adding in a thin film shape, a method of adding in a net shape, a linear shape, a granular shape, an island shape, a belt shape, or the like can be appropriately used.

The method of adding a material that emits photoelectrons can be made by coating or adhering to the surface of an appropriate material by a known method. For example, an ion plating method, a sputtering method, an evaporation method, a CVD method, a plating method, a coating method, a stamp printing method, and a screen printing method can be appropriately used. The thickness of the thin film may be a thickness at which photoelectrons are emitted by irradiation of ultraviolet rays or radiation, and may be 5 to 5,000,
Usually, 20 to 500 degrees is common. The used shape of the base material includes a plate shape, a pleated shape, a cylindrical shape, a rod shape, a linear shape, a net shape, a fiber shape, a honeycomb shape, and the like. Further, the tip of the convex portion may be sharpened or spherical (Japanese Patent Publication No. 6-7490).
No. 8).

As for the addition of the thin film to the base material, one type or two or more types of materials can be used in a single layer or in a multi-layered manner as already proposed by the present inventors. That is, a plurality of thin films can be used as appropriate (composite) to form a double structure or a multiple structure of more than that (Japanese Patent Laid-Open No. 4-152296). The optimum shape, the type and addition method of the material that emits photoelectrons by irradiation with ultraviolet light, and the thickness of the thin film are determined by the type, scale and shape of the device, the type of photoelectron emitting material, the type of base material, and the strength of the electric field described below. Preliminary tests can be performed as appropriate in consideration of how to apply, effect, economy, and the like. When the photoelectron emitting material is used in addition to the base material, the base material may be ceramic, clay, or a well-known metal material in addition to the above-described ultraviolet ray transmitting material. Alternatively, the surface of a light source described below can be coated with the above-mentioned photoelectron emitting material (the light source and the photoelectron emitting material are integrated) (Japanese Patent Laid-Open No. 4-243540).

It can be integrated with a photocatalyst described later (Japanese Patent Application No. 8-132563). In this mode, the photocatalyst can stabilize the photoelectron emitting material for a long time (can be removed even if there is a substance affecting the photoelectron emitting material) and can remove coexisting gaseous pollutants. Is preferred in some cases. The generation of photoelectrons by irradiating the photoelectron emitting material with ultraviolet light is performed by forming an electric field (electric field) between the photoelectron emitting material (negative electrode) and an electrode (positive electrode) described later. Happens. The method (structure) of forming the electric field can be appropriately selected depending on the shape and structure of the charged portion, the application field, the type of the device, the expected effect (accuracy), and the like. The intensity of the electric field can be determined as appropriate depending on the type of addition to the photoelectron emitting material or the base material, and this is another invention of the present inventors. The strength of the electric field is
Generally, it is 0.1 V / cm to 2 kV / cm.

Next, an irradiation source for ultraviolet irradiation will be described. Usually, a mercury lamp, a hydrogen discharge tube, a xenon discharge tube, a Lyman discharge tube, or the like can be appropriately used as the ultraviolet light source.
Examples of the light source include a germicidal lamp, a black light, a fluorescent chemical lamp, a UV-B ultraviolet lamp, and a xenon lamp. Among them, a germicidal lamp (wavelength: 254 nm)
Is preferred because it has a bactericidal (sterilizing) action on airborne fungi, microorganisms, and the like that coexist with the particulate matter. That is, by using a germicidal lamp as an ultraviolet light source, a germicidal action can be added simultaneously with collection and removal of the particulate matter, and thus it is preferable depending on the use destination (apparatus type).

Next, the electrodes will be described. The electrode is provided on the opposite side of the photoelectron emitting material (negative electrode) to effectively generate photoelectrons from the photoelectron emitting material, and forms an electric field between the electrode and the positive electrode. The electrode material and its shape may be any as long as it can form the electric field. Any material can be used as long as it does not generate impurities or the like and is a conductive material. For example, SUS, Cu-Z
n and W. The shape is plate-like, pleated, cylindrical, rod-like, linear, fibrous, mesh-like, or honeycomb-like, and can be determined by appropriate preliminary tests depending on the type, shape, and scale of the device or photoelectron emitting material.

Next, a collecting material (dust collecting material) for collecting charged particulate matter will be described. The trapping material is used for collecting and removing charged particulate matter charged in the charged part of the particulate matter in front of the trapping material. The collecting material may be any material that can reliably collect charged particulate matter, and any known charged fine particle collecting material can be used. Dust collection plates and dust collection electrodes for ordinary charging devices Various electrode materials and electrostatic filter systems are common, but steel wool electrodes,
A wool-shaped structure such as a tungsten wool electrode, in which the collecting portion itself forms an electrode, is also effective. Electrec materials can also be suitably used. In addition, the method of collection using an ion exchange filter (or fiber) already proposed by the inventor is also effective (Japanese Patent Publication No. Hei 5-9-1123, Japanese Patent Publication No. Hei 6-123).
87997 gazettes). In the photoelectron method,
The constituent materials such as an ultraviolet lamp, a photoelectron emitting material, and an electrode material can be integrated (unitized) and installed in a space to be cleaned (Japanese Patent Publication No. Hei 8-22393).

(2) Method using photocatalyst Photocatalyst is effective for removing acidic gas, alkaline gas, organic gas (hydrocarbon) as gaseous pollutants, particularly organic gas (15th Air Purification and Contamination). Proceedings of the Nation Control Research Conference, pp. 309-314,
1997). As the method using a photocatalyst, those already proposed by the present inventor can be appropriately used (for example, see Japanese Patent Application Laid-Open No.
168722 and JP-A-9-205046. The photocatalyst, the following photocatalyst material by ultraviolet irradiation,
It exerts a photocatalytic action. Photocatalysts are generally preferred because semiconductor materials are effective, readily available, and have good workability. In terms of effectiveness and economy, Se, G
e, Si, Ti, Zn, Cu, Al, Sn, Ga, I
n, P, As, Sb, C, Cd, S, Te, Ni, F
Any of e, Co, Ag, Mo, Sr, W, Cr, Ba, and Pb, or a compound, alloy, or oxide thereof is preferable, and these are used alone or in combination of two or more.

For example, the elements are Si, Ge, Se,
Compounds include AlP, AlAs, GaP, AlSb,
GaAs, InP, GaSb, InAs, InSb, C
dS, CdSe, ZnS, MoS ₂ , WTe ₂ , Cr ₂
Te ₃ , MoTe, Cu ₂ S, WS ₂ , and oxides such as TiO ₂ , Bi ₂ O ₃ , CuO, Cu ₂ O, ZnO, M
oO ₃ , InO ₃ , Ag ₂ O, PbO, SrTiO ₃ ,
BaTiO ₃ , Co ₃ O ₄ , Fe ₂ O ₃ , NiO and the like are available. For the immobilization of the photocatalyst, a well-known addition method such as a vapor deposition method, a sputtering method, a sintering method, a sol-gel method, a coating method, or a baking method can be appropriately used for an appropriate material (base material). . Additional shapes are thin film,
A linear shape, a net shape, a band shape, a comb shape, a granular shape, an island shape, and the like can be appropriately selected and used according to a base material described later. T above
Since i and Zn can be used as a photocatalyst by, for example, oxidizing plate-like Ti, they can be suitably used depending on the type of the device.

As an example of fixing the photocatalyst, a known conductive material such as SUS, Cu-Z
n, Al, or coating on the surface of ceramic, fluororesin, glass or glassy substance, or coating the photocatalyst on an appropriate material such as plate, granule, island, line, net, film or fiber Alternatively, it may be wrapped or sandwiched and fixed for use. An example is the coating of titanium dioxide on a glass plate by the sol-gel method. The photocatalyst can be used in the form of a powder, but can be used in an appropriate shape by a known method such as sintering, vapor deposition, or sputtering. Further, in order to improve the photocatalytic action, Pt, Ag, Pd, and Ru are added to the photocatalyst.
A substance such as O ₂ or Co ₃ O ₄ can be added for use. The addition of the substance is preferred because the photocatalysis is promoted. These can be used alone or in combination. Usually, the amount added is 0.01 to the photocatalyst.
The concentration is 10 to 10% by weight, and an appropriate concentration can be selected by conducting a preliminary test according to the type of the added substance and the required performance.

As a method of addition, well-known means such as an impregnation method, a photoreduction method, a sputter deposition method, and a kneading method can be appropriately used. The photocatalyst can be installed in the cleaning device by any method as long as the position and the installation method can be effectively applied with the ultraviolet rays from the ultraviolet light source. For example, there is (1) integration with the photoelectron emitting material (Japanese Patent Application No. 8-132563).
There are a method of adding a photoelectron emitting substance and a photocatalyst to the base material, a method of adding a photocatalyst to the photoelectron emitting substance, and a method of adding a photoelectron emitting substance to the photocatalyst. Another example is (2) integration with the above-mentioned electric field electrode material (Japanese Patent Application No. 8-231290). For example, a photocatalyst is added to a SUS material in a mesh or island shape (SU).
(S is a positive electrode), a method of adding a photocatalyst in the form of a film to ceramic, and sandwiching it between open mesh SUS materials (SUS is a positive electrode), (3) a method of installing a photocatalyst in a space where air flows, (4) ) Method of coating on an ultraviolet lamp (Japanese Patent Application No. Hei 8)
No.-31231) and the like, and a preliminary test can be appropriately performed and determined according to the use destination, the type of the apparatus, the condition (concentration) of the processing air, the required performance, and the like.

As the ultraviolet light source, the aforementioned one for photoelectron emission can be similarly used. Also, as already proposed by the present inventor, if the method using photoelectrons and the method using photocatalyst are integrated, the particulate matter and gaseous pollutants can be removed simultaneously with a simple configuration, so that the method of use (type of device) (1) Proceedings of the 14th Air Purification and Contamination Control Conference, p. 201-20
4, 1996, 2) 15th Proceedings, p. 309-31
4, 1997, 3) JP-A-1-266864, Japanese Patent Application 8-352382).

(3) Method of Neutralization by Irradiation of Ultraviolet Light Irradiation of ultraviolet light to a space is performed by charged particulate matter (charged fine particles).
It is effective for removing electricity (losing potential) from a substrate or substrate having a high potential stored in a space. Neutralization by ultraviolet irradiation can appropriately utilize what has already been proposed by the present inventors (Japanese Patent Publication No. 6-45092). In the neutralization method, a gas in which charged fine particles are present is treated by cationization by irradiating ultraviolet rays and generation of photoelectrons by irradiating the photoelectron emitting material with ultraviolet rays. In a case in which a stored high potential base material or substrate is neutralized, an ultraviolet light source, a photoelectron emitting material that emits photoelectrons by irradiation of the ultraviolet light, and an ultraviolet light source that generates cations in a gas are treated in a processing space. It is something that we prepared for.

In the above, it is preferable to provide an electric field electrode for generating an electric field in the processing space in order to adjust the amount of photoelectrons (anions) emitted. Then, the amount of photoelectrons emitted by the electric field and the amount of cations generated by the wavelength and / or intensity of the ultraviolet ray can be controlled simultaneously or separately to adjust the ion balance in the neutralization step. Further, the ultraviolet light source may be provided separately for direct ionization and for photoelectron emission, but may be used for both if low wavelength UV and an appropriate photoelectron emission material are selected. The direct ionization step and the optoelectronic processing step may be performed in the same processing vessel, may be performed separately, or either of the steps may be performed first or after.

The neutralized state depends on whether the inlet fine particles or inlet gas is positive or negative.
It can be determined by the balance between the photoelectron emission amount (negative ion) with respect to the negative charge amount and the cation generation amount depending on the wavelength and intensity of ultraviolet rays. That is, the former (photoelectron emission amount)
Is relatively more, the inclination becomes more negative, and conversely, as the latter (the amount of generated cations) is more, the inclination becomes more positive. These balances, that is, the balance between the amount of emitted photoelectrons and the amount of generated cations, depend on the charge state of the inlet fine particles and gas and the desired degree of neutralization.
It can be determined by conducting a preliminary test or the like as appropriate. For example,
When it is desired to increase the relative proportion of anions, it is generally effective to increase the electric field, or to increase the electric field and use ultraviolet rays having a longer wavelength. On the other hand, when it is desired to increase the number of cations, the electric field is weakened, or the electric field is weakened, and ultraviolet light having a shorter wavelength is used, or the medium gas is easily ionized, for example, N ₂ , Ar, or the like. Changing it is effective. Photoelectron emitting material used here,
As the electrode material for the electric field, the respective materials in the above-mentioned “method by photoelectrons” can be used.

(4) Method using ion exchange fiber Ion exchange fiber is used as a gaseous pollutant for SO ₂ , N ₂
It is effective for removing acidic gases such as Ox and alkaline gases such as NH ₃ and amines. To explain such an ion-exchange fiber, a cation-exchanger or anion-exchanger, or a cation-exchange group and an anion-exchange group are provided on the surface of a support such as a natural fiber or a synthetic fiber, or a mixture thereof. It is a method of supporting an ion exchanger having the same, and as a method thereof, it may be directly supported by a fibrous support, or may be formed into a woven, knitted, or flocked form, and then supported thereon. it can. In any case, it suffices if the fibers finally support the ion exchanger. As a method for producing the ion-exchange fiber used in the present invention, an ion-exchange fiber produced by utilizing graft polymerization, particularly radiation graft polymerization, is suitable. This is because various materials and shapes can be used. Now, wool, silk, etc. can be applied as the natural fibers, and synthetic fibers made of a hydrocarbon polymer, those made of a fluorinated polymer, or polyvinyl alcohol,
Polyamide, polyester, polyacrylonitrile, cellulose, cellulose acetate and the like can be applied.

Examples of the hydrocarbon polymer include aliphatic polymers such as polyethylene, polypropylene, polybutylene and polybutene; aromatic polymers such as polystyrene and polyα-methylstyrene; and alicyclic polymers such as polyvinylcyclohexane. A polymer or a copolymer thereof is used. Examples of the fluorinated polymer include polytetrafluoroethylene, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, ethylene tetrafluoride-hexafluoropropylene copolymer, and vinylidene fluoride-hexafluoride. A propylene copolymer is used. In any case, the support has a large contact area with the gas flow, a small resistance, a shape that can be easily grafted, a large mechanical strength,
It is sufficient that the material has a small effect of falling off of fiber waste, generation and heat, and can be appropriately selected in consideration of the use application, economy, effect, etc. Usually, polyethylene is generally used and polyethylene or polyethylene and polypropylene and Complexes are particularly preferred.

Next, the cation exchanger is not particularly limited, and various cation exchangers or anion exchangers can be used. For example, in the case of cation exchange, for example, carboxyl groups, sulfonic acid groups, phosphoric acid groups, cation exchange group-containing substances such as phenolic hydroxyl groups, primary to tertiary amino groups, quaternary ammonium groups and the like And an ion exchanger having both the positive and negative ion exchange groups. In particular,
For example, acrylic acid, methacrylic acid, vinylbenzenesulfonic acid, styrene, halomethylstyrene,
Acyloxystyrene, hydroxystyrene, styrene compounds such as aminostyrene, vinylpyridine, 2-methyl-5-vinylpyridine, 2-methyl-5-vinylimidazole, after graft polymerization of acrylonitrile,
If necessary, a fibrous anion exchanger having a cation or anion exchange group can be obtained by reacting sulfuric acid, chlorosulfonic acid, sulfonic acid, or the like.

These monomers are graft-polymerized onto fibers in the presence of a monomer having two or more double bonds, such as divinylbenzene, trivinylbenzene, butadiene, ethylene glycol, divinyl ether, ethylene glycol dimethacrylate, and the like. May be. In this way, ion exchange fibers are manufactured. The diameter of the ion exchange fiber is 1 to 1000 μm, preferably 5 to 200 μm.
m, which can be appropriately determined depending on the type of fiber, application, and the like. The use of cation exchange groups and anion exchange groups among these ion exchange fibers can be determined depending on the type and concentration of the component to be removed in the target processing gas. For example, the component to be removed may be measured and evaluated in advance, and the type and amount of the ion exchange fiber corresponding to the measurement and evaluation may be used. Those having a cation exchange group (cation exchanger) when removing alkaline gas, those having anion exchange group (anion exchanger) when removing acidic gas, and those having a mixed gas of both. Fibers having both positive and negative exchange groups can be used.

As the ion-exchange fiber, as previously proposed by the present inventors, it is preferable to use a fiber produced by radiation graft polymerization, since the effect is particularly high, and the fiber can be appropriately used (Japanese Patent Publication No. 5-9123, Tokuhei 5-67325
No., JP-B 5-43422, JP-B 6-24626). The ion-exchange fiber is effective for collecting ionic substances (components), and the acidic gas and alkaline gas targeted by the present invention are considered to be ionic substances. Can be removed. In particular, in the ion exchange filter (fiber) manufactured by radiation graft polymerization, since the irradiation of the support is uniformly performed to the inner part, the ion exchanger (anion and / or cation exchanger) has a large area (high area). (Added to density), firmly (strong)
Therefore, there is an effect that the exchange capacity is increased and an ionic substance having a low concentration can be efficiently removed at a high speed, which is practically effective. In addition, the production by radiation graft polymerization has advantages such as being able to be formed into a shape close to the product, being able to be performed at room temperature, being able to be performed in the gas phase, being able to increase the graft ratio, and being able to produce an adsorption filter with less impurities. Therefore, it has the following features.

The ion exchange fiber (adsorption function portion) is uniformly added to the ion exchange fiber produced by the graft polymerization by irradiation with radiation (the addition density is high), so that the adsorption speed is high and the adsorption amount is large. Low pressure loss. Since this method cannot fluidize the gas in the cleaning space by itself, it is preferable to use this method together with the above-described method of installing an ultraviolet light source (ultraviolet lamp) in a part of the enclosed space. (1) The method using photoelectrons,
(2) a method using a photocatalyst, (3) a method for neutralizing by ultraviolet irradiation, and (4) a method using ion exchange fibers can be used alone or in combination of two or more.
That is, depending on the type, shape, and required performance of the apparatus, preliminary tests can be appropriately performed and used in combination. It is preferable to use it in combination with the method of (2).

For example, (1) fine particles and gaseous pollutants,
In particular, simultaneous removal of gas and particles where the gas is an organic substance,
Combination of photoelectron and photocatalytic methods, (2)
The particulates and gaseous pollutants, especially the gas, are basic gases (NH
₃ ) The simultaneous removal of gas and particles, which are amines, is achieved by combining photoelectron and ion exchange fiber methods. (3)
Simultaneous removal of gas and particles of fine particles and gaseous pollutants (organic gas and basic gas) can be achieved by a method using photoelectrons, a method using photocatalysts, and a combination of ion exchange fibers. Simultaneous removal of gas, basic gas, and acidic gas (NOx, SOx, etc.) is achieved by a combination of a method using a photocatalyst and a method using an ion exchange fiber. (5) In the above (1) to (4), when electricity is further removed. This is achieved by combining the respective methods of neutralizing by ultraviolet irradiation.

[0040]

The present invention will be described below in more detail with reference to examples. Embodiment 1 FIG. 1 is a schematic configuration diagram in which one of the storage space cleaning apparatuses of the present invention is provided in a wafer carrier box in a semiconductor factory.
Shown in Since the wafers in this factory have an active surface and are greatly affected by gaseous contaminants as well as fine particles, carrier boxes are used to prevent contamination from them. In FIG. 1, carrier box 1
Is a processing space A (cleaning means) for mainly processing (removing) organic gas (hydrocarbon, HC) as fine particles and gaseous contaminants in the carrier box. It comprises a storage space B in which the wafer 2 to be cleaned is stored. The processing space A where the cleaning means is installed is:
An ultraviolet lamp 5 for charging and collecting fine particles, a photoelectron emitting material 11 coated on the lamp surface, an electric field electrode material 12 for photoelectron emission, and an electrode material 13 for collecting charged fine particles
And a photocatalyst 4 for removing gaseous pollutants.

Reference numeral 14 denotes a partition plate which is a guiding means of the present invention. The air 10 _-1 cleaned by the processing space A by the partition plate flows near the surface of the wafer 2 (air flow 1).
0 _-3 , 10 _-6 , 10 _-7 ), thereby preventing the wafer 2 from being contaminated. In other words, the carrier box 1 contains a harmful gas that increases the contact angle of the wafer when it adheres to the wafer due to opening and closing of the carrier box (loading and unloading of the wafer) and gas generation from the box material and wafer (gas generation from the wafer coating material). Hydrocarbon (HC) 6 as a (gaseous contaminant) 6 and fine particles 15 which cause a defect due to disconnection or short circuit when attached to the wafer and cause a decrease in yield are present. The H. C6 is decomposed by the photocatalysis of the photocatalyst 4 irradiated with ultraviolet rays from the ultraviolet lamp 5, and is converted into a form that does not increase the contact angle. The fine particles (particulate matter) 15 are charged by photoelectrons emitted from the photoelectron emitting material 11 irradiated with the ultraviolet lamp 5 in FIG. 1 to become charged fine particles, and the charged fine particles serve as a collecting material for the charged fine particles. The storage space B where the wafers are collected and the wafers are present is super-cleaned.

H. in carrier box 1 The movement of the C6 and the fine particles 15 to the processing space A is caused by a gas flow caused by a slight temperature difference between the upper and lower sides of the processing space A caused by irradiation of the ultraviolet lamp 5 in the processing space A (FIG. 1).
And 10 _-1 to 10 _-7 ). Here, NH ₃ as a gaseous pollutant is also removed by the photocatalyst. In this manner, gaseous contaminants and fine particles harmful to the wafer in the air in the carrier box are treated, and the air in the carrier box does not increase the contact angle when a substrate such as a wafer is stored (H. C concentration: 0.01 pp
m, NH ₃ concentration: 1 ppb or less) and Class 1
An ultra-clean space is maintained. Since a substrate such as a wafer does not increase the contact angle, when a film is formed on the surface of the substrate, there is an effect that a strong adhesive force can be formed (Air Purification, Vol. 33, No. 1, p. 1995).

In the first embodiment, the processing space portion A for processing harmful gas and fine particles is installed at one place in the space to be cleaned.
It goes without saying that it can be installed at a plurality of locations depending on the required performance and the like. In FIG. 1, reference numeral 8 denotes a light-shielding material for preventing the ultraviolet light from the ultraviolet lamp 5 from being directly irradiated on the wafer 2. Here, the ultraviolet lamp is a germicidal lamp, the electric field for photoelectron emission is 50 V / cm,
The electric field for collecting charged particles is 700 V / cm, and the photocatalyst is Ti
O _2, which is a Ti material coated with TiO ₂ .

Embodiment 2 FIG. 2 shows that the partition plate 14 of the present invention
It is installed at the center of the storage space B. 2, the same reference numerals as those in FIG. 1 of the first embodiment denote the same meanings,
Similarly, the air 10 _-1 purified by the processing space A is
Flow near the surface of the wafer 2 (air flow 10 ₋₆ , 10 ₋₃ , 10
_-7 ), whereby the wafer 2 is prevented from being contaminated.

Embodiment 3 FIG. 3 shows a wafer carrier box (hereinafter referred to as a carrier box) 1 provided with another storage space cleaning device of the present invention in a semiconductor factory. The carrier box 1 is used in the present wafer to prevent the contamination of the fine particles since the adhesion of the fine particles is a particular problem. The air cleaning of the carrier box 1 is performed by cleaning an ultraviolet lamp 5, a photoelectron emitting material 11, an electrode material 12 for an electric field for emitting photoelectrons, and an electrode material 1 for collecting charged fine particles, which are installed on one side of the carrier box 1.
3 is performed by the processing space A. 14 is a partition plate of the present invention. By the partition plate, the processing space A
The air 10 _-1 thus cleaned flows near the surface of the wafer 2 (air flows 10 _-3 , 10 _-6 , and 10 _-7 ), thereby preventing the wafer 2 from being contaminated.

That is, the fine particles 15 are present in the carrier box 1 by introducing clean room air around the carrier box (in / out of wafers). The fine particles 15 are charged by photoelectrons emitted from the photoelectron emitting material 11 irradiated with ultraviolet rays from the ultraviolet lamp 5 to become charged fine particles, and the charged fine particles are collected by the electrode material 13 as a collecting material for the charged fine particles. The storage space B where the wafer 2 is present is super-cleaned. The movement of the fine particles 15 in the carrier box to the processing space A is caused by a gas flow caused by a slight temperature difference between the upper and lower parts of the processing unit A caused by irradiation of the ultraviolet lamp 5 in the processing space A (FIG. 3). Medium 10 _-1 to 10 _-7 ). In this way, the fine particles in the carrier box are removed, and a space that is ultra-cleaner than in class 1 is maintained. In FIG. 3, the same components as those in FIG. 1 of the first embodiment have the same meaning.

Embodiment 4 FIG. 4 is a view similar to FIG.
4 is installed at the center of the cleaning space B.
4, the same reference numerals as those in FIG. 3 of the third embodiment denote the same meanings, and the air 1 similarly purified by the processing space A.
0 _-1 flows near the surface of the wafer 2 (air flow 10 _-6 , 10
_-3 , _10-7 ), thereby preventing the wafer 2 from being contaminated.

Embodiment 5 FIG. 5 shows a wafer carrier box (hereinafter referred to as a carrier box) 1 provided with another apparatus for cleaning a storage space of the present invention in a semiconductor factory. In this semiconductor factory, class 1
Super Clean Room (Super Clean Zone)
Because of the use of fine particles, there is no major problem with regard to fine particles, and the wafer is a gaseous contaminant, especially H.O. C becomes a problem. Therefore, the carrier box 1 is used to prevent the wafer from being contaminated by the gaseous contaminants. The air purification of the carrier box 1 is performed from a processing space A including an ultraviolet lamp 5 and a photocatalyst 4 installed on one side of the carrier box 1. 14 is a partition plate of the present invention.
The air 10 _-1 cleaned by the processing space A by the partition plate flows near the surface of the wafer 2 (air flow 10 _-3 ,
10 ₋₆ , 10 ₋₇ ), thereby preventing the wafer 2 from being contaminated.

That is, the carrier box 1 contains gaseous contaminants around the carrier box (in / out of the wafer), the material of the carrier box (polymer material), and gas generated from the wafer (gas generated from the wafer coating material). As H.6. C and NH ₃ are present. The gaseous pollutant 6 is a photocatalyst 4 irradiated with ultraviolet rays from an ultraviolet lamp 5.
As a result, the storage space B where the wafer 2 exists is ultra-cleaned. The movement of the gaseous contaminants 6 in the carrier box 1 to the processing space A is
Due to the gas flow (10 _-1 to 10 _{-7 in} FIG. 5) caused by a slight temperature difference between the upper and lower portions of the processing section A caused by the irradiation of the ultraviolet lamp 5 inside. In this way, gaseous contaminants in the carrier box are removed and the H.O. C
Is 0.01 ppm or less, and NH ₃ is an ultraclean space of 1 ppb or less. In FIG. 5, the same components as those in FIG. 1 of the first embodiment have the same meaning.

Embodiment 6 FIG. 6 is a view similar to FIG.
4 is installed at the center of the cleaning space B.
6, the same reference numerals as those in FIG. 5 of the fifth embodiment denote the same meanings, and the air 1 similarly purified by the processing space A.
0 _-1 flows near the surface of the wafer 2 (air flow 10 _-6 , 10
_-3 , _10-7 ), thereby preventing the wafer 2 from being contaminated.

Embodiment 7 FIG. 7 shows another embodiment of the carrier box 1 according to the present invention in Embodiment 5, in which the gaseous contaminants 6 in the carrier box 1 in FIG. It is what you do. Since the ion exchange fiber 16 efficiently collects ionic substances,
This embodiment is effective when NH ₃ , amine, NOx, SOx, HF, HCl, and the like pose a problem. In addition, as shown in FIG. 7, the form using the ion exchange fiber at the front and using the photocatalyst at the rear is preferable depending on the application destination (processing gas conditions and required performance) because the photocatalyst can be used stably for a long period of time. This is a problem that occurs during long-term operation. When the amount of ionic substances is large (high concentration), especially when NOx and SOx are only photocatalysts, oxides generated by oxidation by the photocatalyst adhere to the photocatalyst surface. However, as a result, the effective surface area of the photocatalyst (effective surface area as a photocatalyst) may be reduced to cause a decrease in performance. That is, the present embodiment is particularly effective when a substance containing a product that is oxidized by the photocatalyst and thus adheres to the surface of the photocatalyst is included.

Embodiment 8 FIG. 8 shows a stocker 1 provided with another storage space cleaning device of the present invention in a liquid crystal factory. Since the liquid crystal factory uses a class 1 super clean room (super clean zone), there is no problem in removing fine particles. Therefore, static elimination is performed in the stocker 1. That is, the storage glass substrate 2 is electrically neutralized to prevent the influence of contaminants. The static elimination is performed by the ultraviolet lamp 5, the photoelectron emitting material 11 installed in the processing space A of the stocker, and the electrode 12 for effectively emitting photoelectrons from the photoelectron emitting material. 14 is a partition plate of the present invention. The air 10 _-1 enriched in positive ions or negative ions in the processing space A by the partition plate flows near the surface of the glass substrate 2 (air flows 10 _-3 , 10 _-6 , 10 _-7 ), Thereby, the substrate 2 is neutralized (potential is ± 0 V).

That is, the glass substrate 2 in the stocker 1 is moved in and out by opening and closing the stocker.
The glass substrate 2 has a potential (2,000 V).
Here, the contaminants 6, 1 due to intrusion into the stocker 1 due to opening and closing of the stocker 1 and generation of minute amounts of fine particles and gaseous contaminants from the stock material of the stocker and the glass substrate itself.
There are five. In a glass substrate having a high potential, it is considered that the trace amount of the fine particles 15 and the gaseous contaminants 6 are attracted to cause contamination (the contamination of the glass substrate is accelerated). We are trying to prevent it. Here, the static elimination is performed by generating positive ions by irradiating the air from the ultraviolet lamp 5 to the air in the processing space A and generating negative ions by irradiating the photoelectron emission material 11 with the ultraviolet light from the ultraviolet lamp 5. Done in Negative ions are generated by the photoelectrons generated by the above-described photoelectron method acting on nearby O ₂ and H ₂ O (Aerosol Research, Vol. 8, No. 3, pp. 239-248, 1).
993).

Here, the concentrations and ratios of the generated positive ions and the generated negative ions in the processing space A can be determined by conducting a preliminary test as appropriate according to the type of the substrate stored in the stocker 1, its history, required performance, and the like. Can be. In general, the generation of positive ions can be controlled by the irradiation intensity of the ultraviolet lamp 5, and the generation of negative ions can be controlled by the intensity of the electric field between the photoelectron emitting material 11 and the electrode 12. In this way, the glass substrate 2 stored in the storage space B is neutralized (± 0 V), so that contamination from the minute particles 15 and the gaseous pollutants 6 existing in the stocker 1 is prevented. Reference numeral 8 denotes a light shielding material for preventing ultraviolet rays from the ultraviolet lamp 5 from being directly irradiated on the glass substrate. Arrows (10 _-1 to 10 _-7 ) indicate the UV lamp 5
Is a gas flow caused by a slight temperature difference above and below the space A caused by irradiation in the processing space A.

Embodiment 9 The wafer carrier box shown in FIG.
The wafer was set in the semiconductor factory of No. 0, and the wafer was stored. In the carrier box, as shown in FIG. 1, a partition plate (14 in FIG. 1) of the present invention, a part for removing fine particles by photoelectrons as an air cleaning means, and a part for removing gaseous pollutants by a photocatalyst are left. Then, the following sample gas was introduced, and ultraviolet irradiation was performed, and the concentration of fine particles and the concentration of non-methane hydrocarbon in the carrier box were measured. Wafer carrier box; size: 30 liters, storage wafer: 30 cm, 25 sheets, partition plate; Al plate, ultraviolet light source; germicidal lamp, 4W, photoelectron emitting material;

Electrode; for photoelectron emission: linear SUS, 20 V / cm, for collecting charged fine particles: plate SUS, 750 V / cm, photocatalyst; TiO ₂ coated on Ti plate by sol-gel method, sample gas; air semiconductor factory a clean room class 1000, particle concentration: class 1,000 non-methane hydrocarbon concentration: 1.5 ppm, NH ₃ concentration: 50 ppb, the measurement of particulate concentration; light scattering particle counter, the non-methane hydrocarbon concentration Measurement; gas chromatograph, measurement of NH ₃ concentration; chemiluminescence method, where the fine particle concentration (class) indicates the total number of fine particles of 0.1 μm or more contained in 1 ft ³ .

Results The particle concentration, non-methane hydrocarbon concentration, and NH ₃ concentration in the carrier box are shown below with and without the partition plate. (1) Fine Particle Concentration FIG. 11 shows the relationship between the fine particle concentration and the storage time (operation time of the cleaning of the present invention). In FIG. 11, the sample of the present invention was marked with -〇- mark, and for comparison, a sample which was similarly cleaned except for a partition plate was marked with-△, and a sample without ultraviolet irradiation and no voltage application (blank) was marked with-●-. Indicated by In FIG. 11, ↓ indicates non-detection (1 or less). (2) non-methane hydrocarbon concentration, NH ₃ concentration Retract non-methane hydrocarbon concentration for (operating time of cleaning of the present invention), respectively Figure 12 the NH ₃ concentration relationship, Figure 1
3 is shown. -〇-,-△-,-● in FIGS.
-Marks are the same as those in FIG. In addition, ↓ indicates no detection (FIG. 12: 0.01 ppm or less, FIG. 13: 1 ppb or less). Further, in order to confirm the effect of removing the non-methane hydrocarbons in this carrier box, the contact angle on the wafer was measured 30 minutes and 90 minutes after the carrier box was stored (measurement method: water drop type contact angle meter).

The results were all 4 degrees, the same as the initial value. On the other hand, the contact angle of the wafer exposed to the clean room air for the same time was 10 degrees, and the effect of preventing the increase of the contact angle by this carrier box was recognized. In addition, to confirm the removal of non-methane hydrocarbons, the wafers were exposed to clean room air, the wafers contained in a simple box of the present invention that did not perform the cleaning, and the phthalates on the wafers contained in the boxes of the present invention. (DO
P, DBP). Measuring method: One day, 3 days, and 5 days after exposure to air under the above-described experimental conditions, the wafer was heated to remove deposits on the wafer, and the phthalate was measured by GC / MS. As a result, phthalate esters were detected in both the wafer exposed to the clean room air and the wafer stored in a simple box not subjected to the cleaning according to the present invention. On the other hand, the phthalate ester was not detected in any of the wafers stored in the carrier box (with cleaning operation) of the present invention.

Example 10 In Example 9, a case where no photocatalyst was installed or a case where the photoelectron emitting material and the electrode were not installed was examined in the same manner. Results (1) In the case where no photocatalyst was installed (only in the case of the method using photoelectrons), the same results as those in FIG. 11 were obtained for the fine particle concentration. The non-methane hydrocarbon concentration ranges from 0.7 to 0.
At 9 ppm, almost no effect was observed. (2) When the photoelectron emitting material and the electrode are not installed (in the case of only the method using the photocatalyst), the fine particle concentration is 500 to 600 particles / ft after 90 minutes.
^3, which is considered to be a decrease due to natural sedimentation (reduction due to collision or deposition). As for the non-methane hydrocarbon concentration, the same result as in FIG. 12 was obtained.

Example 11 The carrier box shown in FIG. 7 was used continuously for a long period of time in the atmosphere of the following sample gas, and the contact angle of the substrate was measured with respect to the effect of preventing the Ta coating / glass serving as the storage substrate from being contaminated. I checked by doing. Wafer carrier box; size: 80 liters, partition plate; Al plate, ultraviolet light source, germicidal lamp, photocatalyst; TiO ₂ coated on glass plate by sol-gel method, ion exchange fiber; (anion type, cationic type)

Method for producing ion-exchange fiber: Anion-exchange fiber: Fibrous polypropylene was irradiated with 20 Mrad of electron beam in nitrogen, and then hydroxystyrene monomer and isoprene were added at 60% and 40%, respectively.
The resultant was immersed in a solution containing the solution and heated to a temperature of 35 ° C. to perform a graft polymerization reaction. After the reaction, quaternary amination was performed to obtain an anion exchange fiber. Cation exchange fiber: Fibrous polypropylene was irradiated with an electron beam of 20 Mrad in nitrogen, then immersed in an aqueous solution containing 45% of acrylic acid, and heated to a temperature of 35 ° C. to perform a graft polymerization reaction. After the reaction, the mixture was treated with a sodium hydroxide solution to obtain a cation exchange fiber.

Opening and closing of the carrier box; 24 times / day, sample gas; non-methane hydrocarbon concentration: 1.5 ppm (average), NH ₃ concentration: 500 to 700 ppb, SO ₂ concentration: 600 to 800 ppb, NOx concentration: 500 to 500 Measurement of contact angle on substrate: 600 ppb; water drop contact angle meter, results FIG. 14 shows the relationship of the contact angle of Ta / glass substrate to the number of days of continuous operation. In FIG. 14, the embodiment of the present invention (provided with ion-exchange fibers before the photocatalyst) is denoted by -〇-
For comparison, a photocatalyst-only sample is indicated by-△-, and a blank as it was exposed to the sample gas is indicated by-●-.

[0063]

According to the present invention, the following effects can be obtained. 1) In a method for cleaning a storage space in which a base material or a substrate is stored using ultraviolet light, a partition plate for promoting (effectively utilizing) a convectional flow of the gas to be treated is provided in the storage space. 1) The flow of gas generated by the ultraviolet irradiation is effective for the movement of contaminants in the storage space and the movement of the purified gas for preventing contamination of the base material and the substrate stored in the storage space. became. That is, the effect of preventing the storage base material and the substrate in the storage space from being contaminated is quicker and more effective. 2) As the cleaning means in the above 1), any one of charge and collection of particulate matter by photoelectrons, removal of gaseous pollutants by a photocatalyst, charge elimination by ultraviolet irradiation, and removal of gaseous pollutants by ion exchange fibers By using more than one type, (1) one type or a combination of two or more types can be used as appropriate depending on the application (specification of the device) and the required performance. .

3) From the above, (1) Since local cleaning (mini-combination) will rapidly spread in advanced industries in the future, gaseous organic materials and the like accompanying the use of polymer materials (organic substances such as plastics) will be used. It is necessary to respond to the generation of pollutants (measure technology). However, in the present invention, gaseous pollutants are effectively removed as described above. It could be used favorably. (2) In the future, base materials and substrates in high-tech industries will become larger, and the base materials and substrates are in a direction of being handled horizontally (operation in the process is performed horizontally). By using the apparatus having the above, cleaning using ultraviolet rays was effectively performed. 4) As described above, in the local space cleaned according to the present invention, the cost can be reduced in the product process, so that the applicable range is widened and the practicality is improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a wafer carrier box to which one of the storage space cleaning apparatuses of the present invention is applied.

FIG. 2 is a schematic configuration diagram of a wafer carrier box to which another one of the storage space cleaning apparatuses of the present invention is applied.

FIG. 3 is a schematic configuration diagram of a wafer carrier box to which another one of the storage space cleaning apparatuses of the present invention is applied.

FIG. 4 is a schematic configuration diagram of a wafer carrier box to which another one of the storage space cleaning apparatuses of the present invention is applied.

FIG. 5 is a schematic configuration diagram of a wafer carrier box to which another one of the storage space cleaning apparatuses of the present invention is applied.

FIG. 6 is a schematic configuration diagram of a wafer carrier box to which another one of the storage space cleaning apparatuses of the present invention is applied.

FIG. 7 is a schematic configuration diagram of a wafer carrier box to which another one of the storage space cleaning devices of the present invention is applied.

FIG. 8 is a schematic configuration diagram of a stocker to which another one of the storage space cleaning devices of the present invention is applied.

FIG. 9 is a schematic configuration diagram of a conventional air cleaning device in a clean room.

FIG. 10 is a schematic configuration diagram of a conventional wafer stocker.

FIG. 11 shows the particle concentration (number / particle) depending on the operation time (min).
³ is a graph showing a change in ft ³ ).

FIG. 12 is a graph showing a change in a methane hydrocarbon concentration (ppb) depending on an operation time (min).

FIG. 13 shows the NH ₃ concentration (pp) according to the operation time (min).
The graph which shows the change of b).

FIG. 14: Contact angle (degree) based on the total operation time (hr)
The graph which shows the change of.

[Explanation of symbols]

1: wafer carrier box, 2: wafer, 3: wall material,
4: Photocatalyst, 5: UV lamp, 6: Organic gas, 7:
Detoxifying gas, 8: light shielding material, 10 _1-7 : air current, 11: photoelectron emitting material, 12: electric field electrode material for photoelectron emission, 13: collecting electrode material, 14: partition plate, 15: fine particles, 16: Ion exchange fiber

Claims (4)

[Claims] 1. A method for cleaning a storage space in which a substrate or a substrate is stored having a cleaning means using ultraviolet light as a light source, wherein the flow of gas in the storage space is promoted by convection in the storage space. A method for cleaning a storage space, comprising providing a guiding means. 2. The method according to claim 1, wherein the cleaning means is at least one of charging and collecting particulate matter by photoelectrons, removing gaseous pollutants by a photocatalyst, and removing electricity by ultraviolet irradiation. 2. The method for cleaning a storage space according to claim 1, wherein a combination of removal of gaseous pollutants by ion exchange fibers is used. 3. The method according to claim 1, wherein the guiding means is a partition plate. 4. A storage space in which a base material or a substrate is stored,
A purifying device for purifying the storage space, the cleaning device having:
A partition plate for promoting a convective flow of gas in the storage space; a charge / collection unit for particulate matter by photoelectrons; and a removal unit for gaseous pollutants by a photocatalyst as the cleaning means. An apparatus for cleaning a storage space, comprising: at least one of means for removing electricity by ultraviolet irradiation; or means combining these means with a section for removing gaseous pollutants by ion exchange fibers.