JP3316166B2 - Filter, manufacturing method thereof, and cleaning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter for removing gaseous organic impurities in an atmosphere used in a cleaning apparatus such as a clean room or a clean bench.

[0002]

2. Description of the Related Art At present, cleaning apparatuses are widely used for manufacturing LSIs and LCDs. For example, when an organic substance adheres to a wafer in these manufacturing processes, the withstand voltage of the insulating oxide film (SiO ₂ ) is reduced, exposure / etching defects are caused by the reduced adhesion of the resist film, and the surface resistivity of the wafer is increased due to an increase in surface resistivity. In addition, various inconveniences such as further electrostatic attraction of particles due to charging are caused.
In addition, when an organic substance adheres to a glass substrate as an LCD substrate, when forming amorphous silicon (a-Si) for a thin film transistor (TFT) on the surface thereof, L
Poor adhesion between the CD substrate and the a-Si film occurs. As described above, organic substances derived from the atmosphere of the cleaning device are used in semiconductors and LCs.
D adversely affects the production of D.

On the other hand, organic substances adhering to the surface of the substrate can be removed by a cleaning technique such as ultraviolet / ozone cleaning. However, the cleaning time per substrate requires several minutes, and frequent cleaning causes a decrease in productivity. As described above, particularly in recent years, in addition to the contamination of the substrate by metal impurities and particles, the influence of organic impurities present in the atmosphere of the cleaning apparatus on semiconductor production has been regarded as a problem. For example, US SEMATECH is 19
Technology T announced on May 31, 1995
transfer # 95050512A-TR "For
ecast of Airborne Molecul
ar Containment Limits f
or the 0.25 Micron High P
performance Logic Process "
According to the description, in 1998, the amount of organic contaminants allowed on the surface of a silicon wafer in semiconductor manufacturing was 5 × 10 ¹³ carbon atoms / cm ² in the pre-process and 1 in the post-process.
It is necessary to control the concentration of gaseous organic impurities in the atmosphere of the cleaning device so that the concentration becomes 10 ¹⁵ carbon atoms / cm ² .

[0004] Conventionally, as a means for removing gaseous organic impurities contained in the atmosphere of a cleaning apparatus, a chemical filter for adsorbing and removing gaseous organic impurities using activated carbon has been used. As a simplest form of a chemical filter using activated carbon, a filling cylinder having a configuration in which granular activated carbon is packed in a predetermined case or the like is known. As other forms, a chemical filter in which fibrous activated carbon is combined with an organic binder of low melting point polyester or polyester non-woven fabric to form a felt shape, or granular activated carbon is firmly adhered to urethane foam or non-woven fabric with an adhesive. Block-shaped and sheet-shaped chemical filters are also known.

[0005]

For example, in the case of a clean room in which the ceiling surface is a surface from which clean air is blown out, a chemical filter is arranged upstream of the particle removal filter mounted on the ceiling. But,
This is an extremely effective means for removing gaseous organic impurities in the air atmosphere of a clean room. However, activated carbon is a flammable substance specified in the Fire Service Law, and strict attention must be paid to fire. Therefore, from the viewpoint of disaster prevention,
Chemical filters using activated carbon are difficult to place on the ceiling.

[0006] A cleaning device used for manufacturing semiconductors and LCDs usually has a temperature of 23 to 25 ° C and a relative humidity of 40 to 25 ° C.
The atmosphere is kept at 55%. However, activated carbon adsorbs not only gaseous organic impurities but also moisture in the air. For this reason, if a chemical filter using activated carbon is installed on the air supply side to the cleaning device, the activated carbon used in the chemical filter will remain in the air even if the humidity is adjusted to a predetermined level upstream of the chemical filter. Therefore, the humidity in the cleaning device becomes lower than a predetermined value. The decrease in humidity facilitates the generation of static electricity, which hinders the manufacture of semiconductors and LCDs.

[0007] The conventional chemical filter of the filling cylinder type has a drawback that the efficiency of adsorbing organic substances is high, but the pressure loss (ventilation resistance) is high. On the other hand, a felt-shaped or sheet-shaped chemical filter has excellent air permeability and adsorption efficiency is not so inferior to that of a packed tube, but the filter material (eg, nonwoven fabric, organic binder, etc.) and activated carbon are attached to the sheet. Adhesive (for example, neoprene resin,
Gaseous organic impurities generated from urethane-based resin, epoxy-based resin, silicone-based resin, etc., or sealing materials (eg, neoprene rubber, silicon rubber, etc.) used to fix the filter medium to the surrounding frame, pass through the chemical filter. May be contained in the air, which may adversely affect semiconductor manufacturing. Further, these felt-shaped and sheet-shaped chemical filters remove gaseous organic impurities generated from the chemical filter itself again in the passing air while removing trace organic impurities of the order of ppb contained in the clean room atmosphere. Mixed in.

Japanese Patent Application Laid-Open No. 61-10 / 1986 describes this type of filter.
No. 3518 and JP-A-3-98611. The former is a filter in which an aqueous solution containing powdered activated carbon, an emulsion-type fixing aid, and a solid acid is impregnated into a base material made of urethane foam and then dried. Gaseous organic substances are desorbed from the dispersed organic adhesive and from the urethane foam itself. In the latter case, it is essential that a binder is used in combination with the adsorbent. However, polyethylene and other organic substances are shown as the binder, and desorption of gaseous organic substances from the filter itself is inevitable.

Accordingly, it is an object of the present invention to provide excellent disaster prevention, no reduction in humidity, no desorption of gaseous organic impurities from the filter itself, and a small amount of gaseous organic impurities contained in the air to be treated. It is an object of the present invention to provide a filter capable of preventing contamination of the surface of a substrate or the like by the same organic substance by removing the same. Further, the present invention provides a method for producing such a filter and a cleaning apparatus.

[0010]

In order to solve the above problems, according to the present invention, a zeolite for removing gaseous organic impurities in an atmosphere is provided on a surface of a support. A filter having the property of adsorbing water and having an effective pore diameter larger than the effective pore diameter of the zeolite, fixed using an inorganic substance as a binder to form an adsorption layer.

In the present invention, the surface of the support is
Zeolite for removing gaseous organic impurities in the atmosphere is fixed by using an inorganic substance as a binder to form a first adsorption layer, and the property of adsorbing gaseous organic impurities on the surface of the first adsorption layer And a second adsorption layer formed by fixing an inorganic substance having an effective pore diameter larger than the effective pore diameter of the zeolite. In this filter, the inorganic substance used as the binder for forming the first adsorption layer may have an effective pore diameter larger than the effective pore diameter of the zeolite.

In the present invention, the surface of the support is
A zeolite for removing gaseous organic impurities in the atmosphere is granulated by using an inorganic substance having a property of adsorbing gaseous organic impurities and having an effective pore diameter larger than the effective pore diameter of the zeolite as a binder. It is a filter characterized by having pellets adhered thereto.

In the present invention, the surface of the support is
A zeolite for removing gaseous organic impurities in the atmosphere is granulated by using an inorganic substance as a binder to form pellets, and the periphery of the pellets has a property of adsorbing gaseous organic impurities, and the zeolite has A filter formed by coating a pellet formed by coating an inorganic substance having an effective pore diameter larger than the effective pore diameter described above.

In the filter of the present invention , for example, when a zeolite having an effective pore diameter of 8 angstroms is used, the molecular diameter that cannot be adsorbed by the zeolite such as BHT or siloxane contained in the atmosphere is larger than 8 angstroms. Gaseous organic impurities are 8
Inorganic substances having an effective pore diameter larger than Å can be removed, and gaseous organic impurities having a molecular diameter smaller than 8 Å, such as DOP and DBP, can be removed by zeolite. In the present invention, the “binder” has a function of fixing the zeolite to the support and a function of bonding the zeolites to each other as one layer.

In the filter of the present invention, the support may be, for example, a honeycomb structure. On the spot
In this case, it is preferable that the honeycomb structure is a support having inorganic fibers as an essential component. Not only this support,
Since the zeolite as the adsorbent and the binder used for fixing the zeolite to the surface of the support are also inorganic, no gaseous organic matter is eliminated from the material constituting the filter of the present invention. In the present specification, the honeycomb structure is not limited to a so-called honeycomb structure, and may have a lattice-like or wave-like cross section. Further, the structure of the support is not limited to the honeycomb structure, but may be any other structure that allows other air to pass through the inside of the structure. For example, a three-dimensional network structure such as rock wool can also be suitably used as a support. In this case, as described later, zeolite as the adsorbent of the present invention can be fixed not only in the plane direction of the network structure but also in the depth direction. The method of adhering the adsorbent to the surface of the support may be a method of fixing with an inorganic binder, or a method in which zeolite, which is an adsorbent, is granulated using an inorganic substance as a binder, and the pellet is adhered to the surface of the support. There is a way to do that.

[0016]

In the present invention, zeolite for removing gaseous organic impurities in the atmosphere is granulated by using an inorganic substance as a binder to form pellets. A filter characterized in that the casing is filled with pellets formed by coating an inorganic substance having an adsorption property and having an effective pore diameter larger than the effective pore diameter of the zeolite.

Similarly, in this filter, when a zeolite having an effective pore diameter of 8 Å is used, for example, the molecular diameter that cannot be absorbed by the zeolite such as BHT or siloxane contained in the atmosphere is larger than 8 Å. Gaseous organic impurities are
Inorganic substances having an effective pore diameter larger than 8 Å can be removed, and gaseous organic impurities having a molecular diameter smaller than 8 Å, such as DOP and DBP, can be removed by zeolite. In addition, flexibility in design is obtained such that the shape and size of the casing and the filling amount of pellets can be appropriately selected according to the shape and area of the air flow path and the installation conditions of the filter.

Here, the zeolite may be hydrophobic or hydrophilic. Hydrophobic zeolites absorb less moisture in the air than hydrophilic zeolites,
The original adsorption capacity of the porous zeolite structure does not decrease due to moisture adsorption. Therefore, there is an advantage that the life of the filter is longer than that of the hydrophilic zeolite. On the other hand, hydrophilic zeolites have the advantage of being cheaper than hydrophobic zeolites.

[0020] The effective pore size of the zeolite is not less 7 angstroms, and has a property of adsorbing gaseous organic impurities, in the inorganic material having a larger effective pore diameter than the effective pore size of the zeolite, 15 ~ 3
It is preferable that the total volume of the pores distributed in the range of 00 angstroms is 0.2 cc / g or more per the weight of the inorganic substance, or the specific surface area of the pores of the inorganic substance is 100 m ² / g or more. The main components of the inorganic substance having an effective pore diameter larger than the effective pore diameter of the zeolite are, for example, porous clay mineral, diatomaceous earth, silica, alumina, a mixture of silica and alumina, activated alumina. , Aluminum silicate, porous glass, or a mixture thereof. The porous clay mineral is selected from the group consisting of a hydrated magnesium silicate clay mineral having a ribbon-like structure such as sepiolite and palygorskite, activated clay, acid clay, activated bentonite, and a composite of microcrystals of aluminosilicate metal salt and silica fine particles. Or a mixture thereof is good. In any case, the inorganic substance having the property of adsorbing the gaseous organic impurities and used as a binder having an effective pore diameter larger than the effective pore diameter of the zeolite is obtained by mechanically applying the zeolite powder to the surface of a support. Ability to carry on zeolite or as a binder when granulating the zeolite into pellets, and ability to adsorb gaseous organic impurities having a molecular diameter larger than the effective pore diameter of the zeolite, which cannot be adsorbed by the zeolite Have together. Preferably, the filter is made of only a material that does not generate gaseous organic impurities, and the filter is made of only a material that does not contain combustibles.

[0021] The inorganic substance may include an inorganic fixing adjuvants. In this case, the inorganic fixing aid preferably contains at least one of sodium silicate, silica and alumina.

Further, in the present invention, the support is made of a zeolite powder for removing gaseous organic impurities in the atmosphere, a zeolite powder having a property of adsorbing gaseous organic impurities, and an effective fine particle of the zeolite. An impregnated layer of an inorganic powder used as a binder having an effective pore diameter larger than the pore diameter is impregnated into a suspension in which the powder is dispersed, and then dried to form an adsorption layer on the surface of the support. It is a manufacturing method.

In the present invention, the support is impregnated with a suspension of a zeolite powder for removing gaseous organic impurities in the atmosphere and an inorganic substance used as a binder, and then dried. Forming a first adsorptive layer on the surface of the support, furthermore, an inorganic powder having a property of adsorbing gaseous organic impurities and having an effective pore size larger than the effective pore size of the zeolite. A method for producing a filter, wherein a second adsorption layer is formed on the surface of the first adsorption layer by impregnating the dispersed suspension and then drying.

According to these filter manufacturing methods, the filter can be made only of a material that does not generate gaseous organic impurities. Further, the filter is substantially composed of only a material containing no combustible material.
In this manufacturing method, when the first adsorption layer is formed on the surface of the support, or when the second adsorption layer is formed on the first adsorption layer, the suspension of the inorganic substance is used. When an inorganic fixing aid in a sol state is mixed into the mixture, the inorganic substance contains the inorganic fixing aid.

[0025] In the present invention, in a cleaning device provided with a mechanism for circulating the air humidity is adjusted, the circulation path of the air, arranged in the above-mentioned filter, the downstream side of the filter particles A particle removal filter for removing the impurity particles. According to this cleaning device,
It is possible to remove gaseous organic impurities in the air circulating in the cleaning device without lowering the humidity. This cleaning device is excellent in disaster prevention because it does not use activated carbon, which is a combustible material. Therefore, the filter and the particle removal filter can be arranged on the ceiling of the cleaning device.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a filter according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic exploded view of a filter 1 according to an embodiment of the present invention. As shown
The entire surface of a honeycomb structure 12 having a structure in which a thin sheet 11 having no irregularities is sandwiched between adjacent corrugated sheets 10
The powder zeolite is fixed using an inorganic substance having an effective pore diameter larger than the effective pore diameter of the zeolite as a binder. That is, as shown in the figure, the filter 1 is arranged in the flow direction of the processing air (in the figure, the white arrow 1).
The outer sheet 15a, 15b, 15c, 15d made of aluminum is assembled so as to open in the direction indicated by 3), and a corrugated sheet 10 and a thin plate in which zeolite in powder form is fixed on the surface thereof using the above-mentioned inorganic substance as a binder in the inner space. Sheet 1
1 are alternately stacked substantially parallel to the air flow direction 13. The outer shape and dimensions of the filter 1 can be arbitrarily designed according to the installation space.

Here, an example of a method for manufacturing the filter 1 will be described. First, three materials of inorganic fiber (ceramic fiber, glass fiber, silica fiber, alumina fiber, etc.), organic material (mixture of pulp and molten vinylon) and calcium silicate are blended in an equal weight of 1: 1: 1 and wet-processed. The paper is formed to a thickness of about 0.3 mm by a paper making method. Instead of calcium silicate, a fibrous crystal clay mineral such as sepiolite or palygorskite containing magnesium silicate as a main component may be used. This paper sheet is corrugated by a corrugator, and the resulting corrugated sheet 10 is bonded to a thin sheet 11 made of the same material into a thin sheet shape with an adhesive to obtain a honeycomb structure 12 as shown in FIG. This honeycomb structure 12 is placed in an electric furnace at about 400 ° C. for 1 hour.
A heat treatment for about an hour removes all organic components. Since countless depressions of micron size remain on the surface of the honeycomb structure after the organic components are removed, the porous honeycomb structure 12 having the depressions as holes can be manufactured. Later, the fine particles of the adsorbent and the binder will fit into the depression. Next, inorganic substances used as a binder having a property of adsorbing zeolite powder and gaseous organic impurities and having an effective pore diameter larger than that of zeolite, such as clay mineral, diatomaceous earth, silica, and alumina. The honeycomb structure 12 is immersed in a suspension in which a mixture of silica, alumina, aluminum silicate, activated alumina, and porous glass are dispersed for several minutes, pulled up, and dried by heat treatment at about 300 ° C. for about 1 hour. As shown in FIG. 2, the adsorbing layer 20 is formed by fixing zeolite powder to the surface of the corrugated sheet 10 and the thin sheet 11 constituting the honeycomb structure 12 with an inorganic substance used as a binder. 1 can be obtained. The suspension may contain at least one inorganic fixing aid such as sodium silicate or silica sol or alumina sol. The role of the inorganic fixing aid is that the zeolite powder and the inorganic substance used as the binder are firmly fixed to the surface of the honeycomb structure 12 (including the inner surface of the cell which is an element of the honeycomb structure 12 (the same applies hereinafter)). Acts as an auxiliary for The filter 1 thus obtained does not contain flammable substances in the constituent material, and all the gaseous organic impurity components causing surface contamination contained in the constituent material when the filter is heat-treated are desorbed and removed. Therefore, no gaseous organic impurities are generated from the filter 1 itself.

Next, another method of manufacturing the filter 1 will be described. Until the honeycomb structure 12 is manufactured, the manufacturing method is the same as the above-described manufacturing method, and a description thereof will be omitted. This manufacturing method is characterized in that pellets produced by granulating zeolite powder are adhered to the surface of the honeycomb structure 12 with an adhesive. When granulating the zeolite powder, an inorganic substance having a property of adsorbing gaseous organic impurities and having an effective pore diameter larger than the effective pore diameter of the zeolite was mixed with the zeolite powder as a binder between the zeolites. When the zeolite powder and the inorganic substance used as the binder are mixed together in a state that contains an appropriate amount of water and an inorganic fixing aid, clay-like viscosity and plasticity are exhibited and granulation becomes possible.
The kind of the inorganic substance or the inorganic fixing aid used as the binder is the same as in the above-described production method.

Further, another method of manufacturing the filter 1 will be described. Until the honeycomb structure 12 is manufactured, the manufacturing method is the same as the above-described manufacturing method, and a description thereof will be omitted. Even with this manufacturing method,
On the surface of the honeycomb structure 12, pellets produced by mixing and granulating zeolite powder with an inorganic binder are prepared.
It is characterized in that it is attached with an adhesive. However, the inorganic binder does not necessarily have to have the property of adsorbing gaseous organic impurities and have an effective pore size larger than the effective pore size of zeolite as in the above-described production method. What is completely different from the above-mentioned manufacturing method is the surface structure of the pellet. The surface of the pellet is coated with an inorganic substance having a property of adsorbing gaseous organic impurities and having an effective pore diameter larger than that of zeolite.

FIG. 3 shows that pellets 21 obtained by granulating zeolite using an inorganic substance as a binder are used to form a honeycomb structure 12.
FIG. 3 is a partially enlarged cross-sectional view of a filter 1 having a configuration in which the filter 1 is fixed to the surfaces of a corrugated sheet 10 and a thin sheet 11 constituting the above-described embodiment.
Pellets 21 obtained by granulating zeolite using an inorganic substance as a binder are fixed to the entire surface of the corrugated sheet 10 and the thin sheet 11 with a nonflammable adhesive. In this embodiment, the processing air passes through a thin cylindrical portion 17 having a pseudo-half moon-shaped cross section. Then, the honeycomb structure 12 to which the pellets 21 are fixed is placed in an electric furnace and subjected to a heat treatment at about 100 ° C., which is lower than the heat resistant temperature of the adhesive, for about 2 hours. The filter 1 can be manufactured by desorbing and removing all the gaseous organic impurity components.

The filter 1 thus manufactured is
Because the constituent materials do not contain combustibles, when filter 1 is installed on the ceiling, safety in disaster prevention is lower than when conventional chemical filters based on activated carbon, which is a combustible, are installed on the ceiling. Significantly increase. Note that the cross-sectional shape of the space through which the processing air passes is not limited to the half-moon shape as described above, and may be any shape.

Various cleaning apparatuses for manufacturing semiconductor substrates and glass substrates, for example, clean rooms, clean benches,
Various types of gaseous organic impurities are generated in various-scale cleaning apparatuses such as a clean chamber, various stockers for storing clean products, and a local cleaning apparatus called a mini-environment. However, the cause of substrate surface contamination is limited to high boiling point, high molecular weight organic compounds. For example, organic siloxane generated from sealants in clean rooms, phosphate esters generated from flame retardants in building materials, phthalates generated from plasticizers in building materials, HMDS generated from resist adhesives, BHT generated from cassette antioxidants, etc. It is. Zeolites, especially synthetic zeolites called molecular sieves, have a uniform effective pore size and cannot adsorb gas molecules larger than the effective pore size. For example, if the effective pore diameter is 8
It is possible to adsorb DOP and DBP that cause substrate surface contamination with Angstrom zeolite (because DOP and DBP are smaller than 8 Å in size). However, it is impossible for zeolite having an effective pore size of 8 angstroms to adsorb BHT or siloxane which causes substrate surface contamination (because BHT or siloxane is much larger than 8 angstroms). is there).
In the filter 1 of the present invention, BHT and siloxane, which cannot be adsorbed by zeolite, can be adsorbed and removed by the adsorption of inorganic substances used as a binder for zeolite.

Since zeolite crystals have no self-bonding property, zeolite powder is required to be formed into pellets or to be fixed on the surface of the honeycomb structure 12 in a layered manner.
Binder must be added. Heretofore, clay minerals such as talc, kaolin minerals and bentonite have been generally used for this binder. The total volume (per weight of each binder) of pores distributed in the range of 15 to 300 Å for each of these conventional binders is 0.0
7 cc / g, 0.06 cc / g and 0.03 cc / g, and the specific surface area of the pores of each binder was 28 m ² / g.
g, 21 m ² / g and 23 m ² / g.

These binders which have been used in the past place importance on air permeability, and the main size of the vent formed in the gap between adjacent binder fine particles or between the adjacent binder fine particles and zeolite fine particles is 500 Å or more. there were. In other words, the ventilation holes were macropores that did not cause physical adsorption even though they had extremely good air permeability. Also,
The surface of the binder fine particles itself, such as talc, kaolin mineral, and bentonite, did not have many pores that easily cause physical adsorption. This is because the binder should be used merely to mechanically support the zeolite powder on the surface of the support. To increase the adsorption capacity, the amount of the supported zeolite should be as large as possible, and the binder content in the zeolite Is based on the idea that it is better to have as little as possible. In other words, the binder is required to have a carrying capacity for the zeolite powder and an excellent ventilation capacity so that the gas to be treated can easily reach the surface of the supported zeolite powder.
Adsorption capacity was not required.

On the other hand, in the filter 1 of the present invention, the vent formed in the gap between the adjacent binder fine particles or between the adjacent binder fine particles and the zeolite fine particles is not different from that of the conventional binder, but the filter fine particles of the binder fine particles themselves are formed. Fine pores that are likely to cause physical adsorption on the surface, that is, a pore size of 20
BHT and siloxane, which cannot be adsorbed by zeolite, are present on the surface of the binder fine particles because there are micropores having pores smaller than Å and mesopores having pores having diameters of not less than 20 Å and not more than 500 Å. Is removed by adsorption. In addition, because it has excellent air permeability so that the gas to be treated can easily reach the surface of the zeolite powder, the selective adsorption characteristics of zeolite,
That is, the characteristic that molecules larger than the pore diameter of zeolite are not adsorbed but molecules smaller than the pore diameter are adsorbed and the adsorption performance is extremely excellent is exhibited as in the conventional case. The ease of physical adsorption of gaseous molecules is in the order of micropores, mesopores, and macropores, and macropores are said to hardly contribute to physical adsorption. FIG. 4 is a partially enlarged view of the cross section of the adsorption layer showing the adsorption layer in which the zeolite powder according to the present invention is supported on the surface of the support by inorganic binder fine particles. The target gas is the surface of the adsorption layer
From the (contact surface with the gas to be treated), it enters the adsorption layer and conversely exits from the inside of the adsorption layer, passing through the vent formed between the zeolite fine particles and the binder fine particles. . At this time, gaseous organic impurity molecules enter the pores existing on the surfaces of the zeolite fine particles and the binder fine particles, and are adsorbed and removed.

In order to achieve the object of the present invention, zeolite powder is mainly used for the honeycomb structure 12 by using an inorganic substance having pores mainly in the mesopore region or micropore region larger than the effective pore diameter of zeolite as a binder. Adsorption layer 2
0 to form the filter 1, or the zeolite powder is formed into pellets 21 by the same inorganic binder, and the pellets 21 are formed into the honeycomb structure 12.
To form the filter 1. Further, as shown in the AA cross section and the BB cross section in FIG. 5, zeolite powder is formed into pellets 21 by an inorganic binder having pores mainly in a mesopore region or a micropore region larger than the effective pore diameter of the zeolite. The object of the present invention can also be achieved by molding and filling the pellet 21 into a double cylindrical casing 22 having a large number of vents 23 on the side surface to form the filter 1 '. The processing air flows in from the inner cylinder of the casing 22, passes through the packed layer of the pellets 21 in the casing 22, and then exits through the space between the outer cylinder of the casing 22 and the outer cylinder 24. The flow direction of the processing air is indicated by an arrow 13.

For example, powdery synthetic zeolite having a pore size of 8 Å having a size of several μm is mixed with a powdery acid-treated montmorillonite (activated clay) binder having a size of several μm and fixed to the surface of the honeycomb structure 12. Alternatively, the mixture can be formed into pellets 20 and fixed to the surface of the honeycomb structure 12, or can be filled in a casing to manufacture the filters 1 and 1 'of the present invention. Montmornite is Al ₄ S produced in Montmorion, France.
i ₈ (OH) a ₄ nH ₂ O comprised name given to the clay mineral chemical composition, the montmorillonite acid treatment of a pore size is the pore volume of 15 to 300 Angstroms to about 0.
37 cc / g and the specific surface area is about 300 m ² / g. The ratio of the pore volume in the range of 40 Å to 600 Å in the total pore volume is as high as 22%, and by using acid-treated montmorillonite (activated clay) as a binder for a synthetic zeolite having a pore size of 8 Å. BHT and siloxane having a molecular size larger than 8 Å, which cannot be adsorbed by zeolite, can be physically adsorbed in the pores of the binder.

Talc and kaolinite, which have been conventionally used as a binder for powdered zeolite, have a large crystallite size and a large volume in a macropore region, but have a small internal surface area and volume in a micropore region and a mesopore region. Low adsorption capacity. Also, bentonite, which has been conventionally used as a binder for powdered zeolite, has a large volume in the macropore region, but has a small internal surface area and volume in the micropore region and the mesopore region, and has a small physical adsorption capacity. On the other hand, the pores of sepiolite, which is a fibrous porous clay mineral, are composed of micropores of 10 angstroms and mesopores of 200 angstroms. Acid-treated montmorillonite (active clay), synthetic stevensite, synthetic amesite, synthetic frypontite, composites of fine crystals of metal aluminosilicates such as synthetic frypontite and silica fine particles,
Porous clay minerals, such as sepiolite, have a large physical adsorption capacity. Each of these porous clay minerals
0.2 cc / g of pore volume per unit weight distributed in the range of 15 Å to 300 Å
And the specific surface area is 100 m ² / g or more. Sepiolite, palygorskite, acid-treated montmorillonite (activated clay), and various kinds of porous synthetic clays, which are fibrous porous clay minerals, can be suitably used as the second adsorption layer of the present invention as described later.

Here, among the organic contaminants detected from the substrate surface in the cleaning apparatus, the types having the largest amounts are DOP and DOP.
BP. These are contained in large amounts in the vinyl chloride material, and have a molecular diameter in the range of 6 Å to 8 Å. Therefore, the pore size of zeolite was 7
If the thickness is greater than Å, the most dominant type of DO among the gaseous organic matter that causes organic contamination on the substrate surface
P and DBP are removed by zeolite. On the other hand, gaseous organic impurities having a molecular diameter larger than the effective pore diameter of zeolite are removed by using an inorganic substance having an effective pore diameter larger than the effective pore diameter of the zeolite as a binder of the zeolite.

The strong adsorbing power of zeolite crystals on water and polar substances depends on the electrostatic force of the cation corresponding to the number of aluminum atoms in the skeleton. The content weight ratio SiO ₂ of the silica in the crystal (SiO ₂₎ and alumina (Al ₂ O ₃₎
As / Al ₂ O ₃ increases, the number of cations in the crystal decreases and the hydrophobicity increases. SiO ₂ / Al ₂ O ₃ is 2
About 5 shows hydrophilicity, whereas SiO ₂ / Al ₂ O
_{In the case} of zeolite having ₃ to 20 or more and infinity, hydrophilicity decreases and hydrophobicity prevails.

FIG. 6 shows the weight ratio of SiO ₂ / Al ₂ O ₃ and the amount of water adsorbed per 100 g of zeolite (cc / 100).
g) shows the relationship. When SiO ₂ / Al ₂ O ₃ is 20 or more, the amount of adsorbed water decreases, and when it is 80 or more, almost no water is adsorbed.
Further, FIG. 7 shows an isothermal adsorption diagram of water for a hydrophobic zeolite having a SiO ₂ / Al ₂ O ₃ ratio of 40. For comparison, FIG. 7 shows an isothermal adsorption diagram of water for activated carbon made from coconut shell. Activated carbon at 50% relative humidity
The amount of water adsorbed on (g) (cc) was 0.11 cc / g, and the amount of water adsorbed on hydrophobic zeolite (g) (cc) was 0.03 cc / g.
g. When zeolite adsorbs water, the adsorption capacity of zeolite for gaseous organic substances is reduced by the volume of adsorbed water compared to the case without adsorbed water, so that the adsorption capacity is maintained for a period of time, that is, as an adsorbent. Life is shortened accordingly. In other words, normal relative humidity of 30-60%
It is desirable that the zeolite used to adsorb and remove gaseous organic matter in the cleaning apparatus described above is hydrophobic.

On the other hand, in the present invention, a hydrophilic zeolite may be used. A natural oxide film is formed on the surface of a silicon wafer handled in an air atmosphere in a clean room or a clean bench, though there is some difference, and therefore, the surface of the wafer is hydrophilic. Also,
It is well known that a glass substrate handled in the air atmosphere is also hydrophilic due to the physical properties of the glass itself. An organic substance derived from an air atmosphere that contaminates the hydrophilic surface of a silicon wafer or a glass substrate on which such a natural oxide film is formed has a hydrophilic group that is well compatible with the hydrophilic surface. That is, the organic substance causing the surface contamination described above is a high-boiling high-molecular hydrophobic organic substance having a chemical structure of a carbon double bond or a benzene ring, and naturally has a hydrophobic group. However, these organic substances also have hydrophilic groups that cause surface contamination. As described above, since the electronic material such as the silicon wafer is hydrophilic and the organic substance to be adsorbed has a hydrophilic group, a hydrophilic zeolite can be used.

The silica / alumina ratio of the hydrophilic zeolite is about 2 to 5, and the silica / alumina ratio of the hydrophobic zeolite is 20 to infinity. Hydrophobic zeolites have a longer lifespan as an organic adsorbing material than hydrophilic zeolites, but hydrophobic zeolites are manufactured using a hydrophilic zeolite as a raw material through a process of dealumination by acid treatment and subsequent heating and drying. Price is higher than hydrophilic zeolite. While cost reduction by mass production is easy for hydrophilic zeolite, cost reduction for hydrophobic zeolite is difficult.

Further, zeolite and an inorganic substance having a property of adsorbing gaseous organic impurities and having an effective pore size in a mesopore region or a micropore region larger than the effective pore size of the zeolite are used as a binder. In an embodiment in which the pellets obtained by granulating the zeolite powder are fixed to a support, the zeolite and the inorganic powder are mixed with, for example, city water to form a clay, and the powder is formed into a 0.3 to 0.8 m
Granulate to about m pellets with a granulator. This is sprayed on a support to which an inorganic and nonflammable adhesive has been previously attached by using high-speed air, whereby the filter of the present invention as shown in FIG. 3 can be manufactured. The support is not necessarily limited to the honeycomb structure, but may be a three-dimensional network structure such as rock wool. In the latter, the air to be treated passes across the network structure, so that the air resistance is large, but the chance of contact with the adsorbent is larger than in the honeycomb structure.

FIG. 8 is a schematic exploded view of a filter 31 according to another embodiment of the present invention. In this filter 31, since the configuration of the honeycomb structure 12 itself is the same as the configuration of the air conditioning filter 1 described above with reference to FIG. 1, the same components are denoted by the same reference numerals in FIG. Therefore, detailed description is omitted.

As shown in FIG. 9, the filter 31 has a property of adsorbing gaseous organic impurities on the surface of the honeycomb structure 12 in which the corrugated sheet 10 and the thin sheet 11 are laminated, and has an effective fine zeolite structure. The first adsorption layer 25 was formed by fixing zeolite using an inorganic substance having an effective pore diameter larger than the pore diameter as a binder, and the second adsorption layer 26 was formed by fixing the same inorganic substance on the surface thereof. It has a configuration. The outer shape and dimensions of the filter 31 can be arbitrarily designed according to the installation space. However, the inorganic substance used as a binder when forming the first adsorption layer 25 is different from the inorganic substance used when forming the second adsorption layer 26, and necessarily has the ability to adsorb gaseous organic impurities. And not. Further, the effective pore diameter may be smaller than the effective pore diameter of zeolite. For example, a conventionally used clay mineral such as talc, kaolin mineral, and bentonite having almost no pores involved in physical adsorption may be used. Further, it may be an inorganic fixing aid itself such as sodium silicate, silica sol, and alumina sol. FIG. 10 is a partially enlarged view of a cross section of a composite adsorption layer comprising a first adsorption layer and a second adsorption layer in the present invention.

Here, an example of a method of manufacturing the filter 31 will be described. First, the porous honeycomb structure 12 is manufactured. Before the formation of the adsorption layer, the method is the same as the method described above, and a description thereof will be omitted. Next, the honeycomb structure 12 is immersed for several minutes in a suspension in which zeolite powder and a binder of a conventionally used clay mineral such as talc, kaolin mineral, and bentonite are dispersed, and then at 300 ° C. for 1 minute. The first adsorption layer 25 is formed by drying with a heat treatment for about an hour. Next, an inorganic substance having an effective pore diameter larger than that of zeolite and having a property of adsorbing gaseous organic impurities, such as porous clay mineral, diatomaceous earth, silica, alumina, a mixture of silica and alumina, The honeycomb structure 12 after forming the first adsorption layer is immersed in a suspension in which fine particles such as aluminum silicate, activated alumina, and porous glass are dispersed as a binder for several minutes, and then at about 300 ° C. for one hour. The second adsorbed layer 26 is formed by drying with a heat treatment of a certain degree. Examples of the porous clay mineral include a hydrous magnesium silicate clay mineral having a ribbon-like structure such as sepiolite and palygorskite, activated clay, acid clay, activated bentonite, and a composite of fine crystals of aluminosilicate metal salt and silica fine particles. Thus, the honeycomb structure 12 in which the second adsorption layer 26 is coated on the first adsorption layer 25 can be obtained. The inorganic substance used when forming the first adsorption layer 25 and the second adsorption layer 26 may include at least one inorganic fixing aid such as sodium silicate or silica sol or alumina sol. The role of the inorganic fixing aid is to function as an auxiliary for the zeolite powder and the inorganic binder forming the first adsorption layer 25 to be firmly fixed to the pores of the honeycomb structure 12 and the like. The inorganic substance forming the second adsorption layer 26 functions as an auxiliary agent for firmly fixing the first adsorption layer 25 to the first adsorption layer 25.
The honeycomb structure 12 thus obtained does not contain any combustible materials in the constituent materials, and removes all the gaseous organic impurity components that cause surface contamination contained in the constituent materials when the honeycomb structure 12 is subjected to the heat treatment. Since they are separated and removed, no gaseous organic impurities are generated from the honeycomb structure 12 itself. Further, as the material of the outer frame 15 shown in FIG. 8, it is preferable to use a material which does not generate gaseous organic substances such as aluminum and does not contain flammable substances. Adhesives and sealants used for fixing the honeycomb structure 12 to the outer frame 15 and for closing the gap between the honeycomb structure 12 and the outer frame 15 also do not generate gaseous organic substances and are inflammable substances. It is preferable to have a property not containing In this case, for example, the outer frame 15 is attached to the honeycomb structure 12 and heat treatment is performed on the entire filter 31 that has been assembled, and the non-combustible adhesive or sealant that is a constituent material of the filter 31 causes surface contamination. All gaseous organic impurity components may be desorbed and removed. In this way, the entire filter 31 can be made of only a material that does not contain combustibles, or can be made of only a material that does not generate gaseous organic impurities.

Next, another method of manufacturing the filter 31 will be described. A three-dimensional network structure such as a honeycomb structure or rock wool manufactured by the above-described manufacturing method is used as a support. In this example of the production method, granular zeolite is attached to the surface of the support with an adhesive. As for the granular zeolite, a zeolite powder is mixed with an inorganic substance as a binder, and molded into a pellet shape. A zeolite pellet with a coating layer, in which a coating layer is formed by coating an inorganic substance having an effective pore diameter larger than the effective pore diameter of zeolite and having a property of adsorbing gaseous organic impurities around the pellet, is prepared in advance. Keep it. In order to form a coating layer of an inorganic substance, the pellets are manufactured by immersing zeolite formed into a pellet shape into a suspension in which an inorganic substance for coating is dispersed, and then pulling up and drying. In order to increase the mechanical strength of the coating layer, the suspension contains an inorganic fixing aid in the form of a sol dispersed with the inorganic substance for coating, and the inorganic substance coated on the pellet contains the inorganic fixing aid. You may do so.
The kind of the coated inorganic substance or inorganic fixing aid is as described above.

In the present invention, the structure of the support on which the adsorbent such as zeolite is fixed is not limited to the honeycomb structure 12 described above with reference to FIGS. For example, in FIGS. 1 and 8, the direction of the ridge line of the corrugated sheet 10 arranged with the thin sheet sheet 11 interposed therebetween is arranged parallel to the flow direction of the processing air (the direction of the arrow 13). May be arranged at an appropriate angle to the flow direction of the processing air (the direction of arrow 13). Further, in FIGS. 1 and 8, the ridge lines of the adjacent corrugated sheets 10 are arranged so as to be parallel to each other, but they may be arranged so that the ridge lines of the adjacent corrugated sheets 10 cross each other. In this case, the thin sheet 11 can be omitted because there is no concern that the ridge lines of the adjacent corrugated sheets 10 collide with each other and the adjacent corrugated sheets 10 come into close contact with each other. Even when a support different from the honeycomb structure 12 described with reference to FIGS. 1 and 8 is formed, zeolite can be fixed to the surface by the same method as described above.

FIG. 11 is an explanatory diagram schematically showing a configuration of a cleaning apparatus 101 according to the embodiment of the present invention. Specifically, the cleaning device 101 is, for example, a clean room or a clean bench. The cleaning apparatus 101 includes a processing space 10 for manufacturing, for example, an LSI or an LCD.
2, a ceiling (supply plenum) 103 located above and below the processing space 102 and a floor lower (retanplenum)
104, and a retan passage 105 located on the side of the processing space 102.

The ceiling unit 103 has a fan unit 110
In addition, a clean fan unit 113 having either the filter 1 or the filter 31 described above and a particle removal filter 112 disposed on the downstream side of the filters 1 and 31 for removing particulate impurities is disposed. In the processing space 102, for example, a semiconductor manufacturing apparatus 1 serving as a heat generation source
14 are installed. The lower floor 104 is partitioned by a grating 115 having a large number of holes. In addition, a dry coil 116 for treating a heat load of the semiconductor manufacturing apparatus 114 is provided in the lower floor 104. The dry coil 116 is an air cooler that cools air under conditions that do not cause condensation on the heat exchange surface. A temperature sensor 117 is provided in the urethane passage 105, and the refrigerant pressure regulating valve 118 of the dry coil 116 is controlled such that the temperature detected by the temperature sensor 117 becomes a predetermined set value.

By operating the fan unit 110 of the clean fan unit 113, the air inside the cleaning device 101 flows from the ceiling 103, the processing space 102, the lower floor 104, and the retan passage 105 while the airflow velocity is adjusted appropriately. → It is configured to flow and circulate in the order of the ceiling 103. During this circulation, the cooling is performed by the dry coil 116 and the clean fan unit 11 is cooled.
3, either filter 1 or filter 31;
The gaseous organic impurities and particulate impurities in the air are removed by the particle removal filter 112, and clean air at an appropriate temperature is supplied into the processing space 102.

The particle removing filter 112 is composed of filters 1 and 3
1, the particle removal filter 11
2 has a function capable of removing particulate impurities. Further, the particle removal filter 112 is made of only a material that does not generate gaseous organic impurities.

Further, the intake outside air is supplied to the inside of the lower floor 104 of the cleaning device 101 via a circuit 120 as appropriate.
The circuit 120 includes a filter 1 having a hydrophilic zeolite for removing gaseous organic substances from the intake air.
A unit-type air conditioner 122 is provided upstream of the filter 121 for removing dust, adjusting temperature, and adjusting humidity of intake air. Further, a humidity sensor 127 is disposed in the circuit 120, and the water supply pressure adjusting valve 129 of the humidity control unit of the unit type air conditioner 122 is adjusted so that the humidity detected by the humidity sensor 127 becomes a predetermined set value. Controlled. On the other hand, a humidity sensor 128 is installed in the processing space 102, and the humidity sensor 128
The humidity of the atmosphere in 2 is detected.

From the circuit 120, the lower floor 1 of the cleaning device 101
The intake outside air supplied to 04 is introduced into the processing space 102 via the retan passage 105 and the ceiling 103. Then, an amount of air corresponding to the intake outside air is exhausted from the exhaust port 125 to the outside of the room through the exhaust gallery 126.

The particle removal filter 112 is an ordinary medium-performance filter, HEPA filter, or ULPA filter.
Since a binder containing a volatile organic substance is used for the filter medium, there is degassing from the binder. Therefore, use a filter medium that does not use a binder, or use a filter medium from which volatile organic substances have been removed by baking even if a binder is used. It is desirable to select a type that does not generate any gas, or to fix the filter medium to the frame by physically pressing it with a material that does not degas.

Next, FIG. 12 shows a cleaning apparatus 101 'according to another embodiment of the present invention. In the cleaning apparatus 101 ′ shown in FIG. 12, the filter 1 or the filter 31 described above is not attached to the entire surface of the ceiling 103 of the cleaning apparatus 101 ′, but is thinned out in places. In this example, the number of installed filters 1 and 31 is halved compared to FIG. The other points are the same as those of the cleaning device 101 described above with reference to FIG. Therefore, FIG.
In the cleaning apparatus 101 ′ shown in FIG. 11, the same components as those in the cleaning apparatus 101 described above with reference to FIG. 11 are denoted by the same reference numerals, and detailed description thereof will be omitted.

Organic substances which are generated in a cleaning device for manufacturing semiconductors and cause contamination of the substrate surface include organic siloxanes generated from sealants, phosphate esters generated from flame retardants in building materials, and plasticizers in building materials. Phthalates generated, HMDS generated from the resist adhesive,
High boiling point such as BHT generated from cassette antioxidant
Limited to high molecular organic compounds. The sources of these organic substances are constituent members of a cleaning device such as a clean room or various articles used for manufacturing existing inside the cleaning device, and there are few sources derived from outside air taken in.
Accordingly, the role of the filters 1 and 31 is to remove high-boiling high-molecular organic compounds, which cause surface contamination generated inside the cleaning device, from the circulating air and reduce the concentration of these organic substances inside the cleaning device. It is. When the cleaning device equipped with the filters 1 and 31 is operated, the concentration of organic substances inside the cleaning device is the highest in the early stage of operation, and as the operation time elapses, these organic substances are removed one by one from the circulating air, and the concentration decreases. Finally, it stabilizes at a concentration equilibrium with the amount generated inside the cleaning device. The amount of organic matter removed when air circulates once is 2: 1 when comparing the cleaning device 1 of FIG. 11 mounted on the entire ceiling and the cleaning device 101 ′ of FIG. Have a relationship. In other words, the time from the highest concentration at the beginning of operation to the concentration equilibrium with the amount generated inside the cleaning device is reduced.
In the case of the cleaning device 101 'of FIG. 2, it is considerably longer than in the case of the cleaning device 101 of FIG. In addition, the equilibrium concentration finally reached is slightly higher when thinned out than when mounted on the entire ceiling. In other words, although thinning takes a long time to reduce the concentration, and the equilibrium concentration after the reduction is slightly higher than the case where no thinning is performed, the initial cost of the filters 1 and 31 and the running cost associated with periodic replacement are reduced. Due to the economical desire to do so, the configuration shown in FIG. 12 can be adopted.

[0060]

Next, the operation and effect of the filter according to the embodiment of the present invention described above will be described with reference to examples. First, in a clean room, two types of commercially available chemical filters using granular activated carbon and fibrous activated carbon and a chemical filter using ion-exchange fiber, respectively, and clean room air processed by the filter according to the present invention were used. 4 in total
The change over time of the contact angle on the surface of the silicon wafer with an oxide film was measured in two atmospheres. The result is shown in FIG.
The filter according to the present invention was manufactured as follows. Effective pore size of 8 Å as adsorbent and SiO
₂ / Al ₂ O ₃ 4 μm of hydrophobic zeolite powder was mixed with 3 μm of kaolinite powder as the inorganic substance and dispersed in a slurry dispersed with silica sol as an inorganic fixing aid. After dipping the honeycomb structure, it was dried to form a first adsorption layer. Next, a 3 μm powder of activated clay having an effective pore size of mainly 20 Å to 1000 Å as an inorganic substance having a property of adsorbing gaseous organic impurities is dispersed together with silica sol as an inorganic fixing aid in a slurry. After the above-mentioned honeycomb structure on which the first adsorption layer was formed was immersed again, it was dried to form a second adsorption layer.

The contact angle shown in FIG. 13 was measured by dropping ultrapure water on the surface of the substrate. This contact angle is an index for easily evaluating the degree of organic substance contamination on the substrate surface. Immediately after cleaning, the surface of a silicon wafer or glass with an oxide film free of organic contamination is easily water-compatible, that is, hydrophilic, and has a small contact angle. However, those surfaces contaminated with organic matter are water-repellent, that is, hydrophobic, and have a large contact angle. For example, for a glass substrate surface left in a clean room atmosphere, a measured value of a contact angle by dropping ultrapure water and an X-ray photoelectron spectroscopy (XPS: X-ray)
Photoelectron Spectroscop
It is known that the organic substance surface contamination measured in y) has a correlation as shown in FIG. For the surface of a silicon wafer with an oxide film, there is almost the same correlation between the contact angle and the organic surface contamination. Thus, there is a very strong correlation between the magnitude of the contact angle of water on the substrate surface and the contamination of the organic substance surface.

The following can be understood from the results shown in FIG. Ion-exchange fibers are originally intended to adsorb and remove water-soluble inorganic impurities, cannot adsorb organic substances, and generate gaseous organic substances. An increase in the contact angle of about 10 ° after one day of standing is observed. The two types of activated carbon filters, which should originally prevent organic substance surface contamination, increased the contact angle by about 10 ° after being left for one day, and showed that there was almost no effect of preventing surface contamination. The reason why the two types of chemical filters using activated carbon are not effective is that surface organic contaminants such as binders, sticking aids, and sealants are included in the components of the chemical filter, and the active carbon adsorption effect of the natural filter itself is low. This is because the components have been canceled by degassing. On the other hand, in the filter according to the present invention, gaseous organic impurities are not generated from the adsorptive filter medium itself, so that no organic substance surface contamination occurs and the contact angle does not increase.

Four types of hydrophobic zeolite having a pore diameter of 6 Å, hydrophobic zeolite having a pore diameter of 8 Å, natural activated carbon starting from coconut shell, and synthetic activated carbon starting from petroleum pitch are used. In a clean room atmosphere (23 ° C, 40% RH) for the adsorbent
The adsorption performance of trace organic substances causing surface contamination contained in the water was compared. Trace organic substances that cause surface contamination and are contained in clean room air are mainly DOP and DBP originating from a vinyl chloride material. Each adsorbent 0.0
4 g was packed in a column having a cross section of 0.15 cm ² , and clean room air was supplied at a rate of 3 L / min. Table 1 shows the experimental conditions.

[0064]

[Table 1]

A silicon wafer with an oxide film free from organic contamination immediately after cleaning is exposed to clean room air before passing through the adsorbent 40, and exposed to clean room air after passing through the adsorbent (41: 6 Å). FIG. 15 shows the change in the contact angle of hydrophobic zeolite (42: 8 angstrom hydrophobic zeolite, 43: natural activated carbon, 44: synthetic activated carbon). The contact angle in the figure is a measured value of the wafer surface immediately after cleaning after exposing the wafer surface to target air for 20 hours. The measured value of the contact angle with the wafer surface immediately after the cleaning was 3 °. The following can be seen from FIG. The adsorption performance is in the order of 42>43>41> 44. Especially 44: The synthetic activated carbon is bad. 41: 6 angstrom hydrophobic zeolite and 43: natural activated carbon have an aeration time of 50
Around the time, the adsorption performance starts to decrease. 4
The adsorption performance of the 2: 8 Å hydrophobic zeolite and the 44: synthetic activated carbon does not decrease until the aeration time is 200 hours. In the early stage of use when adsorption performance does not decrease, 4
When comparing the 1: 6 Å hydrophobic zeolite with the 42: 8 Å hydrophobic zeolite, 6 Å changed from 3 ゜ to 6.4 ゜, whereas 8 Å changed from 3 ゜ to 3.1 ゜. . 8 Å hydrophobic zeolite can almost completely adsorb and remove trace organic substances that cause surface contamination contained in the clean room atmosphere, whereas 6 Å hydrophobic zeolite cannot pass surface contamination without being able to adsorb and remove it. It can be seen that there is a trace amount of organic matter that causes. The adsorption performance of 42: 8 Å hydrophobic zeolite and 43: natural activated carbon is much better than that of 41: 6 Å hydrophobic zeolite and 44: synthetic activated carbon. Zeolites cannot adsorb molecules larger than the pore size. Therefore,
42: 8 angstrom hydrophobic zeolite and DOP causing surface contamination in clean room atmosphere
The fact that trace organic substances of DBP and DBP were almost completely absorbed and removed can be understood from the fact that the molecular size of these trace organic substances causing surface contamination is 8 Å or less. On the other hand, the 41: 6 Å hydrophobic zeolite has almost satisfactory adsorption performance as compared with the 44: synthetic activated carbon, but there is a trace amount of organic substances which can not be adsorbed and removed and cause surface contamination. This indicates that the molecular size of the trace organic matter passed through is not less than 6 angstroms and not more than 8 angstroms.

Next, DOP, DBP, and DOP were applied to a filter having a honeycomb structure in which hydrophobic zeolite was used as a first adsorption layer on the surface of a support and activated clay was fixed as a second adsorption layer.
BHT, pentamer siloxane (D5)
Gas chromatography-mass spectrometry (GC-MS) for determining the amount of organic contaminants on the surface of a silicon wafer installed in each atmosphere on the upstream and downstream sides of a filter when clean room air containing several ppb from pt is passed.
The results were measured and compared to evaluate the effect of preventing surface contamination.
Table 2 shows the results.

[0067]

[Table 2]

For the evaluation, a 4-inch p-type silicon wafer was used. The cleaned wafer was exposed on the upstream and downstream sides of the filter, respectively, and the surface contamination was measured. A combination of a heated gas desorption device and a gas chromatograph mass spectrometer was used to analyze and measure the organic substances attached to the wafer surface. In addition, the surface contamination prevention rate was determined as follows based on gas chromatography.

Surface contamination prevention rate = (1- (B / A))
× 100 (%) A: Peak area of the contaminated organic substance detected from the wafer surface on the upstream side B: Area of the peak of the contaminated organic substance detected from the wafer surface on the downstream side

As shown in FIGS. 1 and 8, the filter has a structure in which a thin sheet having no unevenness is sandwiched between adjacent corrugated sheets. The thickness of the filter in the ventilation direction is 10cm,
The ventilation air velocity was 0.6 m / s, and the total surface area of the sheet per unit volume of the filter in contact with the processing air passing through the filter was 3000 m ² / m ³ . In the filter of the present invention, 3 μm of kaolinite (a kind of kaolin mineral) powder is mixed with a hydrophobic zeolite powder having a pore diameter of 8 Å and a size of 3 to 4 μm as a binder, and silica sol is used as an inorganic fixing aid. The porous honeycomb structure described above is immersed in the slurry dispersed together as an agent, and then dried,
A hydrophobic zeolite was fixed to the honeycomb structure as a first adsorption layer. After immersing the porous honeycomb structure on which the first adsorption layer is formed in a slurry in which a binder of powdered acid-treated montmorillonite (activated clay) of several μm is dispersed together with silica sol as an inorganic fixing aid. It was dried and fixed as a second adsorption layer. The thickness of the first adsorption layer is 100 μm, and its weight composition ratio is hydrophobic zeolite: kaolinite: silica = 70%: 25%: 5%, and the thickness of the second adsorption layer is 10 μm, its weight composition ratio Was acid-treated montmorillonite: silica = 87%: 13%. The density of the whole filter was 230 g / liter, and the density occupied by the adsorption layer was 90 g / liter (39% of the whole filter). In Table 2, for comparison, the above-mentioned hydrophobic zeolite powder having an effective pore diameter of 8 Å was mixed with kaolinite powder of 3 μm as a binder, and silica sol was dispersed together as an inorganic fixing aid. The measurement results for a conventional filter manufactured by immersing the porous honeycomb structure in the slurry and drying the slurry are also shown. Kaolinite has a major pore size of 1000 Å or more, and has little physical adsorption capability. On the other hand, activated clay has an effective pore diameter mainly distributed in the range of 20 Å to 1000 Å, and its physical adsorption ability is comparable to that of activated carbon. The shape and ventilation conditions of the honeycomb structure of this conventional filter are exactly the same as those of the filter of the present invention shown in Table 2, and the difference is that the honeycomb filter is fixed to the surface of the honeycomb structure exactly as in the present invention. This is a point that the first adsorption layer, which does not correspond to the second adsorption layer (active clay layer) of the present invention, is provided. It is clear from Table 2 that DOP and DBP, the most abundant types of organic contaminants detected from the substrate surface in the cleaning device, are physically adsorbed on the binder because their molecular sizes are smaller than 8 Å. Even if the ability is not so high, it is adsorbed and removed only by the adsorption ability of hydrophobic zeolite. However, BHT and pentameric siloxane (D5) cannot be removed by hydrophobic zeolite because their molecular size is larger than 8 Å, and their removal by adsorption depends on the second adsorption layer having physical adsorption ability. I have no choice.

Next, the filters of various types manufactured according to the present invention, the filters of the prior art, and the present invention in which the order of fixing the first and second adsorption layers to the support are changed. A comparison was made between two types of filters having different configurations of comparative examples. Table 3 shows the results.

[0072]

[Table 3]

In Table 3, the present invention A is a filter having a honeycomb structure in which the first adsorption layer is made of zeolite and the second adsorption layer is made of an acid-treated montmorillonite binder. The present invention B is a filter in which alumina sol as an inorganic fixing aid is mixed with a binder of zeolite and acid-treated montmorillonite on the surface of a honeycomb structure to form an adsorption layer. The present invention C is a filter in which an acid-treated montmorillonite binder is further formed on the filter surface of the present invention B as a second adsorption layer. In the filter of the conventional example, only the zeolite adsorption layer was formed on the surface of the honeycomb structure. Comparative Example D
Is a filter in which the order of adhering the first adsorption layer and the second adsorption layer to the support of the present invention A is changed. The first adsorption layer is a binder of acid-treated montmorillonite, and the second adsorption layer is a filter. It is a honeycomb structured filter made of zeolite. Comparative Example E is a filter in which the order of adhering the first adsorption layer and the second adsorption layer to the support of the present invention C is changed.
Is a filter having a honeycomb structure comprising an acid-treated montmorillonite binder, and a second adsorption layer comprising a zeolite and an acid-treated montmorillonite binder.

The structure of each filter adsorption layer is shown in FIGS.
21 is shown as a perspective view (a) and a sectional view (b). These figures show the adsorption layer shown in FIG. 4 or FIG.
Partially cut out into a cylindrical shape with the thickness of the adsorption layer as the height,
FIG. 3 is a schematic diagram conceptually showing the distribution of micropores and mesopores, which are pores involved in adsorption, present in the cylinder. In FIGS. 16 to 21, the support is omitted. In the present invention A, as shown in FIG. 16, pores of about 8 Å of zeolite are formed in the first adsorption layer 51, and about 15 to 300 Å of acid-treated montmorillonite is formed in the second adsorption layer 52. About a few pores are formed. In the conventional example, as shown in FIG. 17, pores of about 8 Å of zeolite are formed in the adsorption layer 53. In the present invention B, as shown in FIG. 18, the adsorbent layer 54 has about 8 Å pores of zeolite and about 15 to 3
Pores of about 00 angstroms are formed. In the present invention C, as shown in FIG. 19, in the first adsorption layer 55, pores of about 8 Å of zeolite and pores of about 15 to 300 Å of acid-treated montmorillonite are formed. The adsorption layer 56 has pores of about 15 to 300 angstroms of acid-treated montmorillonite. On the other hand, in Comparative Example D, as shown in FIG.
In the second adsorption layer 61, pores of about 8 Å of zeolite are formed. In Comparative Example E, as shown in FIG. 21, about 15 to 300 angstroms of acid-treated montmorillonite are formed in the first adsorption layer 62, and about 8 angstroms of zeolite are formed in the second adsorption layer 63. About 15 ~ of acid-treated montmorillonite
Pores of about 300 angstroms are formed.

As a result of examining the surface contamination prevention rate of each of these filters in the same manner as described above, the filters of the present invention were all superior to the conventional filters in adsorbing BHT and D5. In the present invention, the adsorptivity was excellent in the order of C, A and B. The adsorption performance of the filter of Comparative Example D was equivalent to the filter of the conventional example, and the adsorption performance of the filter of Comparative Example E was equivalent to the filter of Example B of the present invention. As can be understood from the results in Table 3, the adsorption performance of gaseous impurities having a molecular diameter larger than the effective pore diameter of zeolite, such as BHT and D5, depends on the contact surface with the adsorption layer that directly contacts the gas to be treated. It is determined by how many pores having an effective pore diameter larger than the effective pore diameter of many zeolites are distributed, in other words, how large their area density is. Therefore, when the adsorbing layer is composed of two different layers, the first adsorbing layer and the second adsorbing layer, the area density of pores suitable for adsorbing gaseous impurities having a large molecular diameter such as BHT and D5 is relatively large. An adsorbent layer that is small in size and consequently has poor adsorption performance, and an adsorbent layer that has a relatively large area density of pores suitable for adsorbing gaseous impurities with large molecular diameters, resulting in excellent adsorption performance The order of fixing is such that the adsorption layer having poor adsorption performance is the first adsorption layer directly in contact with the support, and the adsorption layer having excellent adsorption performance is brought into direct contact with the gas to be treated by being superimposed on the first adsorption layer. By forming it as a second adsorption layer, a filter having excellent adsorption performance can be obtained. If the order of fixing to the support is reversed, the adsorption performance of gaseous impurities having a large molecular diameter such as BHT and D5 can be improved. Should be noted because it is inferior.

Further, even with the adsorption performance of gaseous impurities having a molecular diameter smaller than the effective pore diameter of zeolite such as DOP and DBP, no matter how much physical adsorption occurs on the contact surface with the adsorption layer which is in direct contact with the gas to be treated. It is determined by the distribution of the micropores or mesopores involved, in other words, by how large their area density is. Therefore, the adsorption performance of the first adsorption layer in direct contact with the support is not involved. Then, as long as the adsorption performance of the second adsorption layer in direct contact with the gas to be treated is excellent, the structure of the first adsorption layer in direct contact with the support does not matter. The adsorption performance measured in Table 3 means the surface contamination prevention rate before the filter is used for a long time and becomes saturated with gaseous impurities contained in the gas to be treated and its removal efficiency is reduced. The performance specifications include not only the adsorption performance but also the time until the adsorption saturation is reached by gaseous impurities, that is, the life of the adsorption performance. The lifetime is determined by the total pore volume of micropores and mesopores involved in the physical adsorption of the entire adsorbent layer,
Because of these pore areas, not only the second adsorption layer that is in direct contact with the gas to be treated, but also the first adsorption layer that is in direct contact with the support has a structure in which the pore volume and pore area are large. By selecting, a filter with a long life can be obtained.

Next, the cleaning apparatus of the present invention described above with reference to FIG. 11 was actually manufactured, and a silicon wafer substrate with an oxide film having no organic contamination immediately after cleaning was left in the processing space. On the ceiling of the processing space, a fan unit, a filter of the present invention, and a clean fan unit having a particle removal filter were arranged. A hydrophilic zeolite was used for the filter of the present invention. Then, the contact angles were measured immediately after the cleaning and after leaving for 3 days, and the increase in the contact angle after leaving for 3 days was examined.
The measurement of the increase in the contact angle due to standing for 3 days (washing → contact angle measurement → standing for 3 days → contact angle measurement) was repeated every 15 days in the same manner, and the deterioration over time of the adsorption performance of the filter of the present invention was measured. The circulating air flow rate in the cleaning device is 5000m
³ / min, and the amount of hydrophilic zeolite used to treat the circulating air was 5000 kg. The outside air intake amount is 4% of the circulating air flow rate, 200 m ³ / mi.
n. The total volume of the clean room is 3120 m ³
And the number of ventilations per hour was 100 times.

For comparison, the filter provided with zeolite was replaced with a conventional chemical filter in which fibrous activated carbon was combined with a binder of low melting point polyester or polyester non-woven fabric to form a felt, and a silicon wafer with an oxide film was formed. The measurement of the increase in the contact angle due to leaving the substrate for 3 days after washing was repeated every 15 days. In this case as well, the amount of activated carbon used per 1 m ³ / min of ventilation is 1 kg.
And Further, the same measurement was performed when no filter having a zeolite or a chemical filter having a conventional configuration was provided, that is, when gaseous organic impurities contained in the atmosphere of the cleaning device were not removed.

The contact angle on the surface of the silicon wafer with the oxide film immediately after the cleaning was 3 °. Maintaining a contact angle of 6 ° or less on the surface of the silicon wafer with the oxide film exposed for 3 days is a necessary condition required for a cleaning device atmosphere to prevent deterioration in device quality due to gaseous organic impurity contamination. Assume that

FIG. 22 shows the measurement results. Change over time of the contact angle of the surface of a silicon wafer with an oxide film exposed to the cleaning device atmosphere of the present invention, the cleaning device atmosphere provided with a chemical filter having a conventional configuration, and the cleaning device atmosphere in which gaseous organic impurities are not removed. Are compared. The contact angle of a silicon wafer with an oxide film exposed to a cleaning device atmosphere in which gaseous organic impurities are not removed is 3
It increases by 26 ° to 30 ° by standing for days. Regarding the cleaning device of the present invention, 3
Contact angle of silicon wafer with oxide film after standing for 4 days is 4 °
It was kept below. However, as the ventilation time increases, the adsorption performance of the hydrophilic zeolite decreases, and the concentration of gaseous organic substances contained in the air after passing through the filter also increases. That is,
With the increase of the ventilation time to the hydrophilic zeolite, the contact angle of the surface of the silicon wafer with the oxide film exposed to the treated air on the downstream side for a certain time also increases. It can be seen that the use time of the filter of the present invention is about three months until the contact angle of the silicon wafer with the oxide film exposed to the air after passing through the filter for three days reaches 6 °. On the other hand, in the case of the conventional chemical filter, the contact angle of the silicon wafer with the oxide film left standing for 3 days even in the state immediately after the start of use reached 12 °. The reason for this is that degassing from the binder of low melting polyester or polyester non-woven fabric used to carry fibrous activated carbon passes directly through the chemical filter and contaminates the surface of the silicon wafer left downstream. It is because it has been done. Even in the conventional chemical filter, the adsorption performance of the activated carbon decreased with the increase of the aeration time, and reached 20 ° after use for 6 months.

Further, the water adsorption characteristics of the hydrophilic zeolite will be described. Activated carbon made from hydrophilic zeolite with a pore size of 10 angstroms and coal is used.
FIG. 2 shows an adsorption isotherm of water measured in an atmosphere of 5 ° C.
3 is shown. With regard to activated carbon, even a small increase in the relative humidity causes a sudden increase in the amount of saturated water absorbed in the air. For example, an unused activated carbon-impregnated chemical filter that hardly adsorbs moisture is stored in a container having an atmosphere of 20% relative humidity, and the chemical filter is taken out of the storage container to be used, and then the relative humidity is immediately reduced to 50%. When exposed to a clean room atmosphere, the activated carbon will adsorb a large amount of moisture in the air until the adsorption saturation is reached. Relative humidity 20% (water adsorption saturation amount 0.004c
c / g) and 50% (water adsorption saturated amount 0.114cc / g)
The difference in the amount of saturated water absorbed by activated carbon was 0.11 cc /
g. On the other hand, in the case of a hydrophilic zeolite having a pore size of 10 angstroms, the saturated amount of water absorbed at a relative humidity of 20% is considerably large at 26.2 cc / g, but the relative humidity is 20%.
From 50% to 50%, the increase in water adsorption saturation is only 0.02 cc / g. As can be understood from FIG. 23, when a filter equipped with an unused 10 Å hydrophilic zeolite stored in an atmosphere having a relative humidity of 10% or less is used in a clean room atmosphere with a relative humidity of 50%, Even if the relative humidity is adjusted to the specified value on the upstream side, the relative humidity in the cleaning device will be lower than the specified value because the hydrophilic zeolite used in this filter hardly adsorbs moisture in the air. No defects.

As with a chemical filter to which activated carbon is impregnated, the temperature and humidity of the atmosphere at the place of use are investigated before shipment, and moisture corresponding to the temperature and humidity is intentionally adsorbed on the activated carbon of the chemical filter and shipped in a sealed package. There is no need for such troublesome work. This is because an atmosphere with a relative humidity of 10% or less is in an ultra-dry state that cannot be achieved in a normal working environment, and several tens of percent is normal in a normal working environment. Therefore, a filter provided with hydrophilic zeolite is impregnated with activated carbon. It is not necessary to adsorb moisture before shipping like a chemical filter that has been used, and it can be packed and shipped as it is.

The adsorption performance of each of the hydrophilic zeolites having a pore diameter of 6 Å and a pore diameter of 8 Å was examined in the same manner as the hydrophobic zeolite. The results are shown in FIG. In FIG.
1 ′ is a case where the adsorbent provided with a hydrophilic zeolite having a pore diameter of 6 Å was exposed to clean room air after aeration, and a curve 42 ′ was a case where the adsorbent was provided with a hydrophilic zeolite having a pore diameter of 8 Å. This is the case where it is later exposed to clean room air. Adsorption performance is 42> 4
2 '>43>41>41'> 44.

Next, the humidity controllability of the cleaning device according to the present invention provided with a hydrophilic zeolite filter was examined in comparison with a conventional cleaning device provided with a chemical filter. The water supply valve of the humidity controller provided in the unit air conditioner was adjusted by the signal of the humidity sensor provided in the unit air conditioner for dust removal, temperature control and humidity control and the outside air intake circuit after passing through the filter. In order to determine whether the humidity controllability is good or not, humidity sensors are provided inside the cleaning device according to the present invention and the conventional cleaning device, respectively. The amount of outside air taken in was only 200 m ³ / min with respect to the circulating air amount of 5000 m ³ / min.

FIG. 24 shows the measurement results. In a cleaning device equipped with a conventional chemical filter, the chemical filter easily absorbs moisture in the passing air. Therefore, after the chemical filter is installed, it takes about 2 weeks for the activated carbon to absorb moisture and reach an equilibrium state. During this time, the relative humidity inside the cleaning device changes at 45%, which is 5% lower than the set value of 50%. On the other hand, in the cleaning device according to the present invention provided with the filter having the honeycomb structure to which the hydrophilic zeolite was fixed, the relative humidity was maintained at 50% of the set value because almost no moisture in the passing air was adsorbed. In the manufacturing process of LSIs and LCDs, if the humidity falls below the set value, static electricity is likely to be generated on wafers and glass substrates, causing fine particle contamination on those product surfaces and electrostatic breakdown of elements, resulting in a high yield. Decrease. In the case of a cleaning device provided with a chemical filter having a conventional configuration, the product yield was reduced for about two weeks after the filter was installed. However, within the cleaning device provided with the filter according to the present invention, the relative humidity was maintained at the set value immediately after the filter was mounted, and no reduction in the product yield was observed.

As described above, a preferred example of the present invention
Although a cleaning device (so-called clean room) suitably used for the entire process of manufacturing LCDs and LCDs has been described, the present invention is not limited to this example. Mini-environment, local cleaning equipment, cleaning equipment of various scales such as clean benches, clean chambers, and various stockers for storing clean products, air flow that can be processed by the filter of the present invention, circulating air flow, and outside air intake air Various applications are conceivable depending on the processing environment, such as the ratio of the amount and the presence or absence of gaseous organic impurities from inside the cleaning device. The object of the filter of the present invention is not limited to air. Even if an inert gas such as nitrogen or argon is processed, an inert gas suitable for manufacturing semiconductors and LCDs is also used. Needless to say, it can be produced.

[0087]

According to the present invention, the following effects can be obtained. (1). In order to prevent organic contamination on the substrate surface handled by the cleaning apparatus, for gaseous organic substances contained in the atmosphere and causing the substrate surface contamination, for example, DOP or DBP
By adsorbing and removing both gaseous organic impurities having a molecular diameter of less than 8 angstroms such as BHT and siloxane and gaseous organic impurities having a molecular diameter of more than 8 angstroms such as BHT and siloxane. It was possible to produce clean air from which gaseous organic substances causing organic substance contamination on the substrate surface suitable for production of semiconductors and LCDs were removed. B. In the manufacture of semiconductors and LCDs, the use of clean air as the atmosphere of a cleaning apparatus to which the substrate surface is exposed has prevented the organic contamination of the substrate surface. (2). In (1), zeolite is used as an adsorbent for adsorbing and removing gaseous organic impurities having a molecular diameter of less than 8 angstroms, and is used for adsorbing and removing gaseous organic impurities having a molecular diameter of more than 8 angstroms. By appropriately selecting and combining various inorganic substances as adsorbents, It is possible to provide a filter that does not contain combustible materials in its constituent materials. A cleaning device constructed using this filter is superior in terms of disaster prevention in comparison with a cleaning device constructed using a conventional activated carbon adsorbent filter. I was B. It is possible to provide a filter consisting only of a material that does not generate gaseous organic matter that causes substrate surface contamination. A cleaning device constructed using this filter can be constructed using a conventional activated carbon adsorbent filter. Organic contamination on the substrate surface could be more completely prevented as compared to the cleaning device provided. C. Compared with the conventional activated carbon filter, it can provide a filter that absorbs less moisture in the air and has a longer adsorption capacity for gaseous organic impurities. In the cleaning equipment,
Compared to a conventional cleaning device using activated carbon adsorbent filters, humidity control in the cleaning device can be performed more easily, and gaseous organic impurities contained in the atmosphere can be adsorbed and removed for a longer period of time. Was.

The use of a filter provided with a hydrophilic zeolite is extremely safe in terms of disaster prevention as compared with a conventional chemical filter containing activated carbon designated as a flammable substance in the Fire Service Law. Further, this filter has a structure in which hydrophilic zeolite is fixed to the honeycomb structure, so that the ventilation resistance of the processing air can be reduced. Further, even if an air humidity control device is provided upstream of the filter, the hydrophilic zeolite does not absorb moisture, so that humidity control is easy.

[Brief description of the drawings]

FIG. 1 is a schematic exploded view of a filter according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a filter having an adsorption layer formed on a surface.

FIG. 3 is an enlarged cross-sectional view of a filter having pellets fixed to the surface.

FIG. 4 is a partially enlarged view of a cross section of an adsorption layer according to the present invention.

FIG. 5 is a schematic exploded view of a filter according to another embodiment of the present invention.

FIG. 6: Content ratio by weight of SiO ₂ / Al ₂ O ₃ and zeolite 1
Moisture adsorption amount per 00g (25 ° C, 50% relative humidity)
6 is a graph showing the relationship of.

FIG. 7 is an adsorption isotherm of water at 25 ° C. on a hydrophobic zeolite and activated carbon.

FIG. 8 is a schematic exploded view of a filter according to another embodiment of the present invention.

FIG. 9 is an enlarged sectional view of a filter having a first adsorption layer and a second adsorption layer formed on the surface.

FIG. 10 is a partially enlarged view of a cross section of a composite adsorption layer including a first adsorption layer and a second adsorption layer.

FIG. 11 is an explanatory diagram schematically showing a configuration of a cleaning device according to an embodiment of the present invention.

FIG. 12 is an explanatory view schematically showing a configuration of a cleaning apparatus according to another embodiment of the present invention.

FIG. 13 is a graph showing a change over time of a contact angle of a wafer surface exposed to processing air by a chemical filter.

FIG. 14 is a graph showing a relationship between a contact angle and a carbon deposition amount.

FIG. 15 is a graph comparing the adsorption performance of trace amounts of organic substances that cause surface contamination of various adsorbents.

FIG. 16 is an enlarged view of a first adsorption layer and a second adsorption layer of the present invention A.

FIG. 17 is an enlarged view of a conventional adsorption layer.

FIG. 18 is an enlarged view of the adsorption layer of the present invention B.

FIG. 19 is an enlarged view of a first adsorption layer and a second adsorption layer of the present invention C.

FIG. 20 is an enlarged view of a first adsorption layer and a second adsorption layer of Comparative Example D.

FIG. 21 is an enlarged view of a first adsorption layer and a second adsorption layer of Comparative Example E.

FIG. 22 is a graph showing a change over time of a contact angle when a silicon wafer with an oxide film immediately after cleaning is exposed to various atmospheres for 3 days.

FIG. 23 is an adsorption isotherm of water on hydrophilic zeolite and activated carbon.

FIG. 24 is a graph showing changes in relative humidity of a cleaning device provided with an adsorption layer using a hydrophilic zeolite and a cleaning device provided with a conventional chemical filter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Filter 12 Support body 25 1st adsorption layer 26 2nd adsorption layer 101 Cleaning device

Continuation of the front page (56) References JP-A-58-124539 (JP, A) JP-A-61-155216 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B01D 39 / 00-39/20

Claims (14)

(57) [Claims] A zeolite for removing gaseous organic impurities in an atmosphere is provided on a surface of a support with an effective fine particle having a property of adsorbing gaseous organic impurities and having an effective pore diameter larger than the effective pore diameter of the zeolite. A filter, wherein an adsorption layer is formed by fixing an inorganic substance having a pore diameter as a binder. 2. A first adsorption layer is formed by fixing zeolite for removing gaseous organic impurities in the atmosphere on a surface of a support using an inorganic substance as a binder.
A second adsorbing layer formed by fixing an inorganic substance having a property of adsorbing gaseous organic impurities and having an effective pore diameter larger than that of the zeolite on the surface of the adsorbing layer. And filter. 3. A zeolite for removing gaseous organic impurities in the atmosphere is provided on the surface of the support with an effective fine particle having a property of adsorbing gaseous organic impurities and having an effective pore diameter larger than the effective pore diameter of the zeolite. A filter, wherein pellets formed by using an inorganic substance having a pore diameter as a binder are fixed. 4. A pellet is formed on the surface of a support by granulating zeolite for removing gaseous organic impurities in the atmosphere using an inorganic substance as a binder, and further forming a gaseous organic impurity around the pellet. A filter having a property of adsorbing and fixing a pellet formed by coating an inorganic substance having an effective pore diameter larger than the effective pore diameter of the zeolite. 5. The filter according to claim 1, wherein the support is a honeycomb structure. 6. The filter according to claim 5, wherein the honeycomb structure is a structure containing inorganic fibers as an essential component. 7. Granulation of zeolite for removing gaseous organic impurities in the atmosphere using an inorganic substance as a binder.
Into pellets, and the surroundings of the pellets in a gaseous state.
It has the property of adsorbing organic impurities, and
Inorganic substances having an effective pore diameter larger than the effective pore diameter
The pellets formed by
A filter characterized in that the filter is configured to be packed. 8. An effective pore size of said zeolite is 7 angstrom.
Der above Strom is, and absorption of the gaseous organic impurities
Has a property to adhere and is larger than the effective pore size of the zeolite.
The inorganic material having an effective pore size of 15 to 3
The total volume of pores distributed in the range of
0.2 cc / g or more per the weight of the inorganic substance;
Has a specific surface area of pores of the inorganic substance of 100 m ² / g or more.
Claim 1, 2, 3, 4, 5, 6, or
8. The filter according to any one of items 7. 9. A method for adsorbing said gaseous organic impurities.
Effective pores larger than the effective pore diameter of the zeolite
The main component of the inorganic substance having a diameter is a porous clay mineral,
Sodium, silica, alumina, mixture of silica and alumina
Materials, aluminum silicate, activated alumina, porous glass
Characterized by one or a mixture thereof
Any one of claims 1, 2, 3, 4, 5, 6, 7 or 8
The filter according to. 10. The porous clay mineral has a ribbon-like structure.
Hydrated magnesium silicate clay mineral, activated clay, acid white
Soil, activated bentonite, fine crystals of metal aluminosilicate
Any of silica fine particle composites or their mixture
The filter according to claim 9, wherein the filter is an object. 11. The inorganic material contains an inorganic fixing aid.
And the inorganic fixing aid is sodium silicate, silica or aluminum.
Claims comprising at least one of the following:
Any of 1,2,3,4,5,6,7,8,9 or 10
The filter according to crab. 12. The method according to claim 12, wherein the support is a gaseous organic impurity in an atmosphere.
Zeolite powder to remove debris and gaseous organic
It has the property of adsorbing pure substances and the effective fineness of the zeolite.
As a binder with an effective pore size larger than the pore size
Drying after impregnating in suspension with inorganic powder dispersed
Forming an adsorption layer on the surface of the support
A method for manufacturing a filter, comprising: 13. The method according to claim 13, wherein the support is a gaseous organic impurity in an atmosphere.
As zeolite powder and binder to remove material
Impregnated with a suspension of inorganic powder
Forming a first adsorption layer on the surface of the support by drying
And has the property of adsorbing gaseous organic impurities.
One of the zeolite has a significant effective pore diameter than the effective pore size
After impregnating into a suspension of dispersed inorganic powder
By drying the first adsorbent layer, the second adsorbent layer
A method for manufacturing a filter, comprising forming a deposition layer. 14. A machine for circulating air whose humidity has been adjusted.
In a cleaning device having a structure, the air circulation path includes:
Claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or
11. The filter according to any one of the above items 11 and downstream of the filter.
Filter for removing particulate impurities arranged on the side
A cleaning device comprising: