JPH05107178A - Method and device for charging fine particle - Google Patents

Abstract

PURPOSE:To enable lowering the impressing voltage for electric field, avoiding the effect of the electric field from a clean space and using the device in a space where such a material as wafer possiblly affected by electric field is existing. CONSTITUTION:For the charging method for fine particles 6 in a space using photoelectron 7 generated by applying ultraviolet light 2 and/or radiation to a photoelectron discharging material 3 in an electric field, electrodes 4 for setting electric field and/or photoelectron discharging material 3 are placed in the space where fine particles are existing. The shape of the electrodes and/or the photoelectron discharging material needs to be selected from more than one of metal net, rod, wire, plate and grid and the electrodes 4 and the photoelectron discharging material 3 especially need to be close to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for charging particles in a space, and more particularly to a method and apparatus for setting an electric field in a method for charging particles in a space by photoelectrons generated by a photoelectric effect in an electric field. In the field of charging and utilizing the fine particles, (a) a field of collecting and removing the charged fine particles to obtain a cleaning gas or a cleaning space, a field of obtaining a cleaning liquid, and (b) charging particles , The field of measuring the concentration and particle size of fine particles in gas or space such as air or exhaust gas, or in liquid,
(C) There are fields such as surface modification of fine particles, control of charge amount, separation of fine particles, and classification.

[0002]

2. Description of the Related Art There have been many proposals by the present inventor regarding the charging of microparticles by photoelectrons generated by irradiating a photoelectron emitting material with ultraviolet rays and / or radiation and its utilization. Among the things that the present inventor has proposed in the gas cleaning relationship, the following are particularly relevant to the present invention. (1) JP-A-61-178050 (US Patent 4,
750,917) (2) JP-A-62-244459 (3) JP-A-63-77557 (4) JP-A-63-100955 (5) JP-A-1-262954 Each measurement and measurement relationship (1) JP-A-62-242838, (2) JP-A-2-47536, and (3) Japanese Patent Application No. 1-134781.

Further proposed in relation to separation / classification is Japanese Patent Application No. 1-177198. Other proposals related to charging conditions include (1) Japanese Patent Application No. 1
-120563 and (2) Japanese Patent Application No. 1-1205564. In addition, the proposals related to photoelectron emitting materials include (1) Japanese Patent Application No. 1-155857 and (2) Japanese Patent Application No. 2
No. 153335, (3) Japanese Patent Application No. 2-278123,
(4) There is Japanese Patent Application No. 2-295423. Conventionally, the position of the electrode for setting the electric field and the position of the photoelectron emitting material have been set opposite to each other in the processing space in which the fine particles are present.
That is, the photoelectron emitting material and the electrode were located at both ends across the space to be treated.

[0004]

In the case of setting the electric field by the position of the electrode as described above, the applied voltage becomes high, and there is room for improvement depending on the field of use. Further, depending on the field of use, the electric field (action of the electric field) in the charging space may have an influence, and there is room for improvement in the device and the like. Further, in designing the device, it may be preferable to install the photoelectron emitting material and the electrode in the vicinity because the applied voltage for setting the electric field can be lowered. Further, it has been desired that the applied voltage is lowered and the practicality is improved, and the shapes of the electrode and the photoelectron emitting material are also highly practical.

The above problems will be described below with reference to examples. FIG. 3 is a configuration diagram showing an operation of removing particles in a wafer storage in the semiconductor industry. The wafer storage 1 includes an ultraviolet lamp 2, a photoelectron emitting material 3, an electric field setting electrode material 4,
It is composed of a reflecting surface 5 for the ultraviolet rays from the ultraviolet lamp 2. The fine particles 6 in the wafer storage 1 are the ultraviolet lamp 2
Photoelectrons 7 emitted from the photoelectron emitting material 3 which has been irradiated with
And become charged fine particles 8. The charged fine particles 8
Are collected by the electric field setting electrode material 4. Here, since the wafer storage 1 is a closed space, the electrode field setting electrode material 4
Serves as a collector for charged fine particles. Reference numeral 9 indicates a wafer carrier, and 10 indicates a wafer.

The photoelectron emitting material here is a material in which a photoelectron emitting material is added in a thin film form on the surface of an ultraviolet light transmitting material which has been already proposed by the present inventor (Japanese Patent Application No. 2-295423). Then, 50 Å Au is added to the surface of the glass material. In such a case, the electric field (electric field) is set between the photoelectron emitting material 3 and the electrode material 4, so that the wafer is placed in the electric field. Therefore, depending on the state of the wafer (for example, the surface is activated, If it is) it may be affected by the action of the electric field. Moreover, since the distance between the photoelectron emitting material 3 and the electrode material 4 is long, there is a problem that the applied voltage for setting the electric field becomes high, and there is room for improvement.

Next, an example of an air purifier will be shown. FIG. 4 shows an air purifier 11, which comprises an ultraviolet lamp 12, a photoelectron emitting material 13, an electric field setting electrode material 14, and a charged particle collecting material 15. The fine particles contained in the inlet air 16 are the photoelectron emitting materials 13 irradiated with the ultraviolet lamp 12.
Are charged by the photoelectrons 17 from the above, become charged fine particles, and are collected by the charged fine particle collecting material 15 at the rear side, and clean air 18
Will be discharged next. The particles are charged by the photoelectron emitting material 13.
And forming an electric field between the electric field setting electrode materials 14. With such a configuration, there is a problem that the distance between the photoelectron emitting material 13 and the electric field setting electrode material 14 becomes long and the applied voltage for setting the electric field becomes high. The applied voltage is
From the viewpoint of safety, operation, and cost, it is practically advantageous that it is low. Therefore, an object of the present invention is to provide a method and apparatus for charging fine particles, which can solve the above problems and effectively charge fine particles.

[0008]

In order to achieve the above object, the present invention provides a method for charging fine particles in a space by photoelectrons generated by irradiating a photoelectron emitting material with ultraviolet rays and / or radiation in an electric field. The electrode for setting an electric field and / or the photoelectron emitting material is provided in a space where fine particles are present, and the shape of the electrode and / or the photoelectron emitting material is selected from a wire mesh shape, a rod shape, a linear shape, a plate shape, and a grid shape. This is a method for charging fine particles, characterized in that an electric field is formed in one part of the space by using a material composed of more than one kind.

Further, in order to achieve the above-mentioned other objects, in the present invention, an ultraviolet and / or radiation source, a photoelectron emitting material for generating photoelectrons by irradiation of ultraviolet and / or radiation,
In a device for charging fine particles in a space having an electric field setting electrode, the electric field setting electrode and / or the photoelectron emitting material is provided in the space where the fine particles are present, and the shape is a wire mesh shape, a rod shape, a linear shape, or a plate shape. The charging device for fine particles is characterized by comprising at least one selected from a lattice shape. In the method and apparatus for charging fine particles of the present invention, the position of the electric field setting electrode and / or the photoelectron emitting material is
The distance between them is within 0.5, preferably within 0.3, particularly preferably within 0.1 with respect to the total length 1 of the processing space in which the fine particles are present.

Next, the respective constitutions of the present invention will be described in detail. The photoelectron emitting material may be any material as long as it emits photoelectrons upon irradiation with ultraviolet rays, and a material having a smaller photoelectric work function is more preferable.
r, Ca, Y, Gd, La, Ce, Nd, Th, Pr,
Be, Zr, Fe, Ni, Zn, Cu, Ag, Pt, C
d, Pb, Al, C, Mg, Au, In, Bi, Nb,
Any one of Si, Ti, Ta, U, B, Bu, Sn, P, W or a compound or alloy or mixture thereof is preferable, and these are used alone or in combination of two or more kinds. As the composite material, a physical composite material such as amalgam can also be used. For example, compounds include oxides, borides, and carbides, and oxides include BaO, SrO, and Ca.
O, Y ₂ O ₅ , Gd ₂ O ₃ , Nd ₂ O ₃ , ThO ₂ , Z
rO ₂ , Fe ₂ O ₃ , ZnO, CuO, Ag ₂ O, La
₂ O ₃ , PtO, PbO, Al ₂ O ₃ , MgO, In ₂
O ₃ , BiO, NbO, BeO, etc., and boride includes YB ₆ , GdB ₆ , LaB ₅ , NdB ₆ , Ce.
_{B 6, BuB 6, PrB 6} , ZrB 2 include, as a further carbide UC, ZrC, TaC, TiC, Nb
C, WC, etc.

As the alloy, brass, bronze, phosphor bronze, an alloy of Ag and Mg (Mg is 2 to 20 wt%), Cu
With Be and alloys (Be is 1 to 10 wt%) and Ba and Al
An alloy of Ag and Mg can be used, and an alloy of Ag and Mg, an alloy of Cu and Be, and an alloy of Ba and Al are preferable. The oxide can also be obtained by heating only the metal surface in air, or by oxidizing with a chemical.
As another method, it is also possible to heat before use to form an oxide layer on the surface to obtain a stable oxide layer for a long period of time. As an example of this, an alloy of Mg and Ag can be formed into an oxide film on its surface under the condition of a temperature of 300 to 400 ° C. in water vapor, and this oxide thin film is stable for a long period of time.

Further, as the present inventor has already proposed, a photoelectron emitting material having a multiple structure can be preferably used (Japanese Patent Laid-Open No. 1-155857). Further, a substance capable of emitting photoelectrons in a thin film form may be added to an appropriate base material and used (Japanese Patent Application No. 2-278123). As an example of this, there is a thin film of Au added as a substance capable of emitting photoelectrons on a quartz glass as a UV transparent substance (base material) (Japanese Patent Application No. 2-295423). The shape of these materials to be used may be any shape such as a rod shape, a linear shape, a grid shape, a plate shape, a pleated shape, a curved surface shape, and a wire mesh shape, but a shape having a large irradiation area of ultraviolet rays and a large contact area with the processing space is used. Depending on the device or device, it is preferable that the fine particles present in the cleaning space can be quickly moved to the photoelectron emitting unit.

The emission of photoelectrons from the photoelectron emitting material can be effectively carried out by appropriately using an opposite surface, a curved reflecting surface, etc., as already proposed by the present inventor (Japanese Patent Laid-Open No. 63-63). -100955). The shape and structure of the photoelectron emitting material and the reflecting surface differ depending on the shape and structure of the device or desired effect, and can be appropriately determined. The irradiation source for emitting photoelectrons from the photoelectron emitting material may be any one as long as it emits photoelectrons upon irradiation. In addition to the ultraviolet rays described in this example, electromagnetic waves, lasers, and radiations can be appropriately selected and used according to application fields, device scales, shapes, effects, and the like. Among these, ultraviolet rays and / or radiation are usually preferable in terms of effects and operation surface.

Any type of ultraviolet light may be used as long as the photoelectron emitting material can emit photoelectrons upon irradiation thereof.
Depending on the field of application, those having a sterilizing effect are also preferable. The type of UV light depends on the application field, work content,
It can be appropriately determined depending on the use, economy and the like. For example, in the biological field, it is preferable to use deep ultraviolet rays together from the viewpoint of bactericidal action and efficiency. As the ultraviolet source, any source can be used as long as it emits ultraviolet rays.
It can be appropriately selected and used depending on the application field, the shape of the device, the structure, the effect, the economical efficiency and the like. For example, a mercury lamp, a hydrogen discharge tube, a xenon discharge tube, a Lyman discharge tube, or the like can be used as appropriate. In the biological field, sterilization wavelength 2
It is preferable to use an ultraviolet ray having a wavelength of 54 nm because the sterilizing effect can be used together.

By irradiating with radiation instead of irradiating with ultraviolet rays, the fine particles are similarly charged and the same effect can be obtained. The present inventor has already proposed radiation irradiation (Japanese Patent Laid-Open No. 62-24459).

Next, the positions and shapes of the electric field electrode and the photoelectron emitting material, which are the features of the present invention, will be described. Electrode and /
Alternatively, the photoelectron emitting material is installed in a part of the space at an appropriate position in the space where the particles are present so that an electric field can be formed between the electric field and the photoelectron emitting material, and the photoelectron emitting material (-) and the electrode (+) are provided. An electric field (electric field) is formed between them. Photoelectric electrons are efficiently emitted from the photoelectron emitting material by the electric field, and the cleaning space is highly cleaned by the photoelectrons. The position or shape of the electrode or the photoelectron emitting material can be appropriately selected depending on the space in which the particles are present, and if the applied voltage for the electric field can be lowered and the photoelectrons from the photoelectron emitting material can charge the particles in the space. Any of them may be used, and can be appropriately determined by a preliminary test or the like in consideration of the field of use, device scale, shape, effect, economy, and the like.

The closer the installation distance between the electrode and the photoelectron emitting material is, the lower the applied voltage may be, which is preferable. Generally 20
Within cm, preferably within 5 cm, but can be appropriately determined depending on the scale of the device, field of use, and the like. In general, the position of the electrode and / or the photoelectron emitting material is within 0.5, preferably 0, with respect to the total length 1 (distance from the wall position to the facing wall surface) of the processing space where the fine particles are present. It is good to set it as one part of the space within 0.3, more preferably within 0.1. Further, the shape may be any shape as long as the fine particles existing in the cleaning space portion can quickly move to the photoelectron emitting portion (between the electrode and the photoelectron emitting material). Usually, one kind of wire mesh, rod, wire, plate, and grid can be used, or two or more kinds can be used in combination. In terms of internal effects and design, at least one portion is preferably a wire mesh. Any material can be used for the electrode material as long as it is a conductor, and various electrode materials in known charging devices can be preferably used. An example of this is the tungsten material.

In the present invention, since the gas does not flow, the electric field voltage used in the present invention is effective even in a weak electric field, and the electric field voltage is 0.1 V / cm to 2 kV / cm. The suitable strength of the electric field can be determined by conducting preliminary tests and examinations depending on the field of use, conditions, device shape, scale, effect, economical efficiency and the like. As the collecting material (dust collecting material) for the charged fine particles, any material can be used as long as it can collect the charged fine particles. Various electrode materials such as a dust collecting plate and a dust collecting electrode in an ordinary charging device and an electrostatic filter method are generally used, but a wool-like structure in which the collecting part itself such as a steel wool electrode or a tungsten wool electrode constitutes the electrode Are also valid. Electret materials can also be preferably used.

Further, the method of collecting by using the ion exchange filter (or fiber) which the present inventor has already proposed is also effective (Japanese Patent Laid-Open Nos. 63-54959 and 63-7755).
7 and 63-84656). The ion exchange filter is practically preferable because it can simultaneously collect the coexisting acidic gas, alkaline gas, odorous gas, etc. in addition to collecting the charged fine particles. The type, amount and ratio of the anion exchange filter and cation exchange filter used depend on the charge state and concentration of the charged fine particles in the gas or the type and concentration of the accompanying acidic gas, alkaline gas, odorous gas, etc. It can be decided as appropriate.

For example, the anion exchange filter is effective for collecting negatively charged fine particles and acidic gas, and the cation exchange filter is effective for collecting positively charged fine particles and alkaline gas. The amount and ratio of the filter used correspond to the concentration and concentration ratio of the substance to be collected, and the amount corresponding to these should be taken into consideration in consideration of the application field, shape, structure, effect, economical efficiency, etc. of the device. It may be decided as appropriate. For collection, these collection methods may be used alone, or two or more kinds of these methods may be used in combination as appropriate.

For use in cleaning a closed space where gas flow is small or negligible, it is preferable that the electric field electrode material also serves as or is integrated with the charged fine particle collecting material because the apparatus can be made compact. For example, among the above-mentioned charged particulate matter collecting materials, various electrode materials such as a dust collecting plate, a dust collecting electrode, or a wool-like electrode material such as a steel wool electrode and a tungsten wool electrode are used as an electric field electrode and a collection of charged particulate matter. It is preferable because it can be combined with the above. The fields of application in which the present invention is particularly effective are shown below. (A) A field for collecting and removing charged fine particles to obtain a cleaning gas, a cleaning space, or a cleaning liquid such as chemicals and pure water. (B) Field of measuring fine particles in a gas such as air or exhaust gas or in a space by using charged fine particles. (C) Field of separation / classification of fine particles, surface modification, and control.

[0022]

Embodiments of the present invention will now be described with reference to the drawings, but the present invention is not limited thereto. Example 1 Air cleaning in a wafer storage of a semiconductor factory will be described with reference to the basic configuration diagram of the present invention shown in FIG. Air cleaning of the wafer storage 1 which is a closed space (a space where gas does not flow and can be regarded as a stationary state) is performed by an ultraviolet lamp 2, an ultraviolet reflecting surface 5, and a photoelectron emitting material 3 which are installed outside the wafer storage 1. The electrode 4 for setting an electric field and the collector 4 for charged fine particles (in this configuration, the electrode also serves as the collector) are used.

That is, the fine particles (fine particle substances) 6 in the wafer storage 1 are charged by the photoelectrons 7 emitted from the photoelectron emitting material 3 irradiated by the ultraviolet lamp 2, and become charged fine particles 8 which are charged fine particles 8. Are collected by the collector 4 of charged fine particles, and the cleaning space (A) where the wafer exists is highly cleaned. (The cleaning section A and the photoelectron emission section B are separated from each other.) The photoelectron emission material 3 here is one in which Au is added in the form of a thin film on the surface of the glass material. Is another invention of the present inventors (Japanese Patent Application No.
-295423).

In this way, the fine particles (particulate matter) in the wafer storage 1 are collected and removed, and the wafer storage becomes clean air. In the above, for the irradiation of the photoelectron emitting material with ultraviolet rays, the curved reflecting surface 5 is used, and ultraviolet rays are efficiently irradiated from the ultraviolet lamp 2 to the plate-like photoelectron emitting material 3. The electrode 4 is installed in order to perform photoelectron emission from the photoelectron emission material 3 in an electric field. That is, the photoelectron emitting material 3
And an electric field is formed between the electrode 4 and the electrode 4 (photoelectron emission portion,
B). The fine particles are efficiently charged by the photoelectrons 7 generated by irradiating the photoelectron emitting material 3 with ultraviolet rays in an electric field. The electric field voltage here is 30 V / cm.

Further, the charged particles are collected by using the electrode 4. The electrode material is a wire-mesh Cu-Zn material plated with gold, and is installed at a position 1 cm from the electron emission material (0.05 position with respect to the distance 1 of the total length A + B). 9, 10
Indicates a wafer carrier and a wafer, respectively. In this example, it is preferable to provide an agitating part for the air flow in a part of the wafer storage because the particle removal rate is increased. As this method, there is a heating section for making a temperature difference and a mechanical stirring section, which can be appropriately used. In this example, the wall surface is the photoelectron emitting material 3 and the electric field electrode material 4 is installed in the space where the fine particles are present. The same can be done by installing a photoelectron emitting material.

Embodiment 2 FIG. 2 shows an air purifier 11, which comprises an ultraviolet lamp 12, a photoelectron emitting material 13, an electric field setting electrode material 14, and a charged fine particle collecting material 15. The fine particles contained in the inlet air 16 are charged by the photoelectrons 17 from the photoelectron emitting material 13 irradiated by the ultraviolet lamp 12, become charged fine particles, and are collected by the charged fine particle collecting material 15 at the rear side, and the clean air 18 is discharged. Will be discharged next. The particles are charged by forming an electric field between the photoelectron emitting material 13 and the electric field setting electrode material 4.

The electrode in this example is made of a photoelectron emitting material, and
The position is cm, and the shape is a wire mesh. In FIG. 2, the photoelectron emitting material 13 and the electrode material 14 are provided in parallel with the flow path, but they can be provided at an appropriate position in the right-angled direction or in the middle of the parallel and right-angled directions, and can be appropriately selected depending on the shape, scale, and effect of the device. Can be used. The space in the present invention refers to a space in which a gas such as air or nitrogen exists, a closed system space such as a closed space under vacuum, or a space in which air or various gases flow.

Example 3 The following sample gas was put into the purifier having the structure shown in FIG. 1 and UV irradiation was carried out to measure the particles (particle counter).
Was used to examine the residual rate of fine particles. Purifier size: 10 liters Photoelectron emission material; Quartz glass with Au added in thin film form Electrode material: Wire mesh Cu-Zn at a position 1 cm from the photoelectron emission material (total distance to the wall surface facing the photoelectron emission material) Installed at the position of 0.2 against 1) Charged particulate collection material; Also used as electrode material UV lamp; Sterilization lamp Electric field voltage; 40 V / cm Sample gas (inlet gas); Irradiation time: 30 minutes

A fine particle concentration of 0.1 μm or more was measured with a measuring instrument. The results are shown below. As a blank, when the particle concentration in the purifier after leaving for 30 minutes without ultraviolet irradiation was examined, 90% of the initial concentration (inlet concentration) was recognized (measured). Further, as a comparison, when the wire mesh electrode material was installed on the wall surface side of the purifier 1 facing the photoelectron emitting material, the same measurement was performed, and it was the same as above.

The position of the photoelectron emitting material in the device is
As in Examples 1 and 3, the side near the ultraviolet lamp, or the side opposite to the ultraviolet lamp as in Example 2 (the position of the end of the processing space), and the position of the electrode in Examples 1 and 3 ( In this case, the wall surface on the UV lamp side in Examples 1 and 3 serves as an electrode, and the wire mesh electrode serves as a photoelectron emitting material.
It can be determined at an appropriate position depending on the type and shape of the photoelectron emitting material, the field of use, the shape of the device, the scale, the effect, the economical efficiency, and the like. The type of photoelectron emitting material is a plate-like material, a pleat-like material, a wire-mesh-like material (Japanese Patent Laid-Open No. 61-178050) as already proposed by the present inventor, and a protective film is added on the base material. (Japanese Patent Application No. 1-155857), thin film-shaped one (Japanese Patent Application No. 2-278123), and one added to an ultraviolet-transparent substance (Japanese Patent Application No. 2-295423) described above for the electrode material for electric field. Can be used in combination as appropriate. The combination of the photoelectron emitting material and the electrode material can be appropriately determined depending on the field of use, the scale of the device, the shape, the structure, etc., and when installed in the space part, the fine particles present in the cleaning space part can be promptly transferred to the photoelectron emitting part. Anything can be used as long as it can move.
Among these, the kind of the photoelectron emitting material suitable for the present invention is generally one in which at least one part is a wire mesh (Japanese Patent Laid-Open No. 61-1780).
No. 50), an ultraviolet-transparent substance such as a glass material on which a substance capable of emitting photoelectrons is added in a thin film (Japanese Patent Application No. 2-
295423). In this example, the example of air cleaning has been described, but the particulate matter can be charged and used without any limitation in the field of use.

[0031]

According to the present invention, the following effects can be obtained. (1) When the photoelectron emitting material is irradiated with ultraviolet rays and / or radiation under an electric field, a wire mesh-shaped, rod-shaped, linear, plate-shaped, or grid-shaped electric field setting electrode material and / or photoelectron-emitting material is used as fine particles. By installing it in a part of the existing space, the electrode material for the electric field and the photoelectron emitting material were brought close to each other, so that the applied voltage for the electric field could be lowered. Cost has been reduced. or,
It is advantageous for safety and operation. Photoelectron emission under an electric field in a small space, and then the charged space of the particles causes a processing space (large space) where the particles exist
Of the particles could be charged. In the case of use in a clean space, the region where photoelectrons are emitted under the electric field (photoelectron emission part) and the region of the clean space (clean space part) can be separated. That is, it is possible to clean the space in which the "substance" that may be affected by the electric field (electric field) exists. (The space can be cleaned by eliminating the influence of the electric field.) For example, in cleaning the space where "a substance that may be affected by a strong electric field" exists, such as wafers in the semiconductor industry, fine particles It was possible to carry out the charging, collection and removal of the same without affecting the wafer.

(2) The shape of the electric field setting electrode material and / or the photoelectron emitting material is one or more kinds of wire mesh, rod, line, plate, and grid, and this is used in a space where fine particles are present. By installing the microparticles in the cleaning space (A) where the microparticles exist, the microparticles are effectively charged by the photoelectrons from the photoelectron emission part (B). (The particles in A were easily charged because they quickly met the photoelectrons from the opening.) Since the effect of photoelectron emission was improved and stabilized, the particles were charged effectively (the charge was high-performance and stable for a long time). ) Became. Since the fine particles are effectively charged, the apparatus can be downsized (compacted) and the processing capacity is increased.

(3) In each field where fine particles are charged and used, the degree of freedom in device design has increased. Practicality improved.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of an air purifier of the present invention in a wafer storage.

FIG. 2 is a schematic configuration diagram of another air purifier of the present invention.

FIG. 3 is a basic configuration diagram of an air purifier in a previous wafer storage cabinet.

FIG. 4 is a schematic configuration diagram of a previous air purifier.

[Explanation of reference numerals] 1,11 ... Air purifier, 2, 12 ... Ultraviolet lamp, 3,
Reference numeral 13 ... Photoelectron emitting material, 4 ... Electron-collecting material, 5 ... Reflective surface, 6 ... Fine particles, 7 ... Photoelectrons, 8 ... Charged fine particles, 9 ... Wafer carrier, 10 ... Wafer, 14 ... Electric field setting electrode,
15 ... Collection material, 16 ... Inlet air, 17 ... Photoelectron, 18 ...
Clean air

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[Procedure amendment]

[Submission date] July 22, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction content]

Example 3 The following sample gas was put into the purifier having the structure shown in FIG. 1 and UV irradiation was carried out to measure the particles (particle counter).
Was used to examine the residual rate of fine particles. Purifier size: 10 liters Photoelectron emission material; Quartz glass with Au added in thin film form Electrode material: Wire mesh Cu-Zn 1 cm from photoelectron emission material
Position (total length distance to the wall facing the photoemissive material 1
Installation charged particle collecting material to 0.05 position) against the; combined UV lamp in the electrode material; germicidal lamp electric field voltage; 40V / cm Sample gas (inlet gas); Irradiation time; 30 minutes ────────────────────────────────────────────── ────────

[Procedure amendment]

[Submission date] September 25, 1992

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 4]

Claims (4)

[Claims] 1. In a method of charging fine particles in a space by photoelectrons generated by irradiating a photoelectron emitting material with ultraviolet rays and / or radiation in an electric field, the electrode for setting an electric field and / or the photoelectron emitting material has the presence of fine particles. Is provided in the space, and the shape of the electrode and / or the photoelectron emitting material is a wire mesh,
A method of charging fine particles, which comprises using one or more kinds of materials selected from rod-shaped, linear, plate-shaped and lattice-shaped materials. 2. The position of the electrode for setting an electric field and / or the position of the photoelectron emitting material is such that the distance between them is within 0.5 with respect to the total length 1 of the processing space in which fine particles are present. The method for charging fine particles described. 3. An ultraviolet and / or radiation source, a photoelectron emitting material for generating photoelectrons upon irradiation with ultraviolet and / or radiation, and a device for charging particles in a space having an electric field setting electrode, wherein the electric field setting electrode and / or Alternatively, the photoelectron emitting material is provided in the space in which the fine particles are present, and the shape is made of one or more kinds selected from a wire mesh, a rod, a line, a plate, and a lattice, and the fine particle charging device is characterized. 4. The position of the electric field setting electrode and / or the photoelectron emitting material is provided within a distance of 0.5 with respect to the total length 1 of the processing space in which fine particles are present. The particulate charging device described.