WO1999028967A1

WO1999028967A1 - Box for transferring semiconductor wafer

Info

Publication number: WO1999028967A1
Application number: PCT/JP1998/005369
Authority: WO
Inventors: Toshiaki Fujii; Osamu Horita; Kouji Ohyama; Toshiya Nakayama; Fumio Sakiya; Mineo Kimpara; Sin Yokoyama; Masataka Hirose
Original assignee: Ebara Corporation; Dainichi, Shoji K.K.; Rorze Corporation
Priority date: 1997-11-28
Filing date: 1998-11-30
Publication date: 1999-06-10
Also published as: JPH11217119A; JP3305647B2

Abstract

A box (21) for transferring a semiconductor wafer, having an opening/closing mechanism for putting in/taking out a wafer, characterized by comprising a gas cleaning device A-2 which uses photoelectrons produced by irradiation with light and an optical catalyst for cleaning the interior of the box, or a gas cleaning unit which includes the gas cleaning device and a battery-mounted power source device with a function of charging the battery for supplying electric power to the gas cleaning device. Thus, the box has a practically effective function of removing fine particles and gaseous harmful components.

Description

Specification

Transport box for semiconductor substrates

(Technical field)

The present invention relates to a transport box for semiconductor substrates, and particularly to a transport box (carrier) for storing and transporting substrates such as Si wafers, glass substrates, and metal-coated substrates in advanced industries such as semiconductors, liquid crystals, and precision machinery. Box) concerning.

(Background technology)

The air cleaning in a conventional clean room will be described with reference to FIG. 14 by taking air cleaning in a semiconductor manufacturing plant as an example.

In FIG. 14, the outside air 1 is first filtered to remove coarse particles by the pre-filter 2, then air-conditioned by the air conditioner 3, and is dust-removed by the medium-performance filter 4. Next, the HEPA filter (high-performance filter) 6 installed on the ceiling of the clean room 5 removes fine particles, and the clean room 5 is maintained in the class 100 to 1,000 (see “Cleaning design”). P. 1 1-2 4, Summer 1 9 8 8). Ί 7 _-2 indicates a fan, and arrows indicate the flow of air.

The conventional air purifier in a clean room is designed to remove fine particles, so it was configured as shown in Figure 14. Such a configuration is effective for removing fine particles, but is not effective for removing gaseous harmful components.

On the other hand, in a large-room clean room as shown in Fig. 14, there is a problem that the cost is too high for ultra-cleaning (BRE AK THROUGH, No. 5, p. 38-41, 19) 9 3).

By the way, in the future, in the semiconductor industry, the quality and precision of products are progressing steadily, and accordingly, not only fine particles (particulate matter) but also gaseous substances are involved as pollutants in addition to fine particles. In other words, removal of fine particles was sufficient in the past, but control of gaseous substances (gaseous harmful components) will become important in the future. This is because the conventional clean room filter shown in Fig. 14 only removes only fine particles, This is because gaseous harmful components from methane are introduced into the clean room without being removed, which is a problem.

In other words, in a clean room, fine particles (particulate matter) and dust removal filters (eg, HEPA, UL PA filters) are not collected and removed, but are introduced into the clean room. Organic gas called hydrocarbon (HC) and basic (alkaline) such as NH ₃ and amine due to degassing of automobile exhaust gas and degassing from polymer resin products widely used as consumer products Gaseous substances such as gas pose a problem as gaseous harmful components.

Of these, H.C. must be removed because it is a gaseous harmful component that has a very low concentration in normal air (indoor air and outside air) that causes contamination.

In recent years, degassing from polymer resins in cleanroom components and equipment (eg, wafer storage boxes) has become a problem as a source of H.C. (Japan Machinery Federation, 1994 report, March 1995, p. 41-49, 199 5).

These gaseous substances also pose a problem if they are generated during work in a clean room. That is, as a cause of the gaseous substance, in a normal clean room, the gaseous substance introduced from the outside air (the gaseous substance cannot be removed at the fill in the clean room, so the gaseous substance in the outside air is introduced. In addition, since the gaseous substances generated in the clean room are added, the gaseous substances in the clean room have a higher concentration than the outside air, and contaminate the wafer substrate and the substrate.

That is, if the above contaminants (fine particles, gaseous harmful components) adhere to the substrate surface of a wafer, semi-finished product, or product, the fine particles cause a disconnection or short circuit of a circuit (pattern) on the substrate surface, causing a defect. In addition, as a gaseous substance, ① H. C. causes an increase in the contact angle when it adheres to the surface of the substrate (substrate), and H. C. increases the affinity (familiarity) between the substrate and the resist. Affect. When the affinity deteriorates, the film thickness of the resist is adversely affected, and the adhesion between the substrate and the resist is adversely affected (empty). Kiyoshi, Vol. 33, No. 1, p. 16-21, 199 5). In addition, H.C. causes deterioration of the breakdown voltage (reliability) of the oxide film in Jehachi (Proceedings of the 39th Joint Lecture Meeting on Applied Physics, p.686, 1992) ).

(2) NH ₃ causes the formation of ammonium salt and causes clouding (defective resolution) on wafers (Realise, latest technology course, collection of materials, semiconductor process seminar, October 29, 1996) Pp. 15-25, 1996).

For these reasons, these gaseous contaminants as well as fine particles reduce the productivity (yield) of semiconductor products.

In particular, since the above gaseous substances as gaseous harmful components are used due to the above-mentioned generation, and more recently, the circulation of clean room air is increased from the viewpoint of energy saving, the concentration of gaseous substances in the clean room is reduced. It is concentrated and has a considerably higher concentration than the outside air. It adheres to the substrate and substrate and contaminates the surface. The degree of this contamination can be represented by the contact angle between the substrate and the substrate. If the contamination is severe, the contact angle is large. Substrate / substrate with a large contact angle, even if formed on the surface, has low adhesion strength of the film (poor adaptability), leading to a decrease in yield.

Here, the contact angle is the contact angle of water wetting, and indicates the degree of contamination of the substrate surface. That is, when hydrophobic (oil-based) contaminants adhere to the substrate surface, the surface repels water and becomes less wettable. Then, the contact angle between the substrate surface and the water droplet increases. Therefore, if the contact angle is large, the degree of contamination is high, and if the contact angle is small, the degree of contamination is low.

In particular, since the air in the clean room is recently circulated for energy saving, gaseous harmful components in the clean room gradually increase, and contaminate the substrate and substrate.

As a measure to prevent the contamination of the substrate from such contaminants, (1) transport by robot is effective. In other words, since humans are a source of dust and gas, it is important to eliminate human intervention to maintain cleanliness. (Monthly Semiconductor worl d, January issue, p. 112-116, 199 7).

(2) In terms of cleanliness, it has been proposed that local cleanup (mini-environment), which limits the clean space (localization), will be effective in future cleanliness (① NIKKEI MICRODEVICES) Procedings of IES, p. 373-378, 199), July issue, p.

At present, as such a mini-environment, a method of storing and transporting Si wafers in a box made of synthetic resin (plastic) is being studied, but f) When dust is generated suddenly from inside Instead, particle contamination becomes serious. (2) Measures must be taken against degassing (gas generation) from box materials. (3) Since (1) and (2), the number of processes for regularly cleaning the posox itself increases. It has been pointed out that this is complicated and practically problematic (KANOMAX Aerosol Seminar 1, pp. 1-10, 1996).

Under such circumstances, the present inventors have proposed a space cleaning method using photoelectrons or photocatalysts as a local cleaning technology.

For example: 1) Photo-electron cleaning method (removal of particulate matter): Japanese Patent Publication No. 3-5 859, Japanese Patent Publication 6-74909, Japanese Patent Publication 8-211, Japanese Patent Publication 7-21 No. 369, 2) Cleaning method using photocatalyst (removal of gaseous harmful components): Japanese Patent Application Laid-Open No. Hei 9-198672, Japanese Patent Application Laid-Open No. Hei 9-205046, 3) Photoelectron and photocatalyst Combination method (simultaneous removal of particles and gas): There is a patent No. 2623290.

These cleaning methods are effective in the above-mentioned cleaning methods depending on the application destination (the type of equipment) and the required performance, but depending on the application destination and the required performance, it is necessary to appropriately improve the usage.

In this improvement, there was a problem that the improvement was made to be more effective in practical use. One of the problems is that in these cleaning systems, the gas is fluidized by heat generated by a light source such as ultraviolet rays to perform cleaning. That is, depending on the application of the cleaning method, it is important how to effectively fluidize the gas, and this is a problem to be improved. In view of the above prior art, the present invention provides a mini-environment semiconductor substrate, which is increasingly required in advanced industries such as the semiconductor, liquid crystal, and precision machine industries, as the quality of the product is increased, refined, and miniaturized. An object of the present invention is to provide a transfer box for semiconductor substrates having a practically effective function of removing fine particles and gaseous harmful components as a transfer box.

(Disclosure of the Invention)

In order to solve the above-mentioned problems, the present invention provides a semiconductor substrate transport box having an opening / closing mechanism that allows a semiconductor substrate to enter and exit, wherein the box uses photoelectrons and photocatalyst by light irradiation for cleaning the inside of the box. This is a semiconductor substrate transfer box having a gas cleaning unit integrated with a gas cleaning device.

Further, according to the present invention, there is provided a semiconductor substrate carrying box having an opening / closing mechanism capable of moving a semiconductor substrate in and out, wherein the box includes a gas purifying device using photoelectrons and a photocatalyst by irradiating light for cleaning the inside of the box. Further, the present invention provides a semiconductor substrate transfer box having a gas purifying unit integrated with a power supply unit having a charging function and a battery for supplying power to the device.

The transfer box is preferably made of synthetic resin, and the gas cleaning unit includes a radiator for transmitting heat generated by the power supply device to the gas cleaning device when a power supply device is integrated. Is good.

If the gas purifying unit does not have a power supply unit integrated, the load port, standby place waiting for the process, stocker, etc. should be provided between the transport boxes (other than transport). It operates by receiving power supply through connection to a power supply device installed in the office.

Hereinafter, the present invention will be described with reference to the accompanying drawings.

(Brief description of drawings)

FIG. 1 is a cross-sectional view showing an example of a horizontally-opening integrated transfer box of the present invention. FIG. 2 is a cross-sectional view showing an example of the open cassette storage type horizontal opening transport box of the present invention.

FIG. 3 is a cross-sectional view showing one example of the open cassette storage type bottom-opening transport box of the present invention.

FIG. 4 is a block diagram in which the gas cleaning unit of the present invention and a power supply device are connected.

FIG. 5 is a block diagram in which the gas cleaning device of the present invention and a power supply device are integrated. FIG. 6 is an explanatory diagram for utilizing heat generated from a power supply device.

FIG. 7 is a cross-sectional view showing another example of the horizontal opening integrated transfer box of the present invention. FIG. 8 is a side view of FIG.

FIG. 9 is a cross-sectional view showing an example of the open cassette storage type horizontal opening transfer box of the present invention.

FIG. 10 is a cross-sectional view showing an example of the open cassette storage type bottom-opening transport box of the present invention.

Fig. 11 is a graph showing the change of contact angle (degree) according to the holding time (day).

Fig. 12 is a graph showing the change in contact angle (degree) with the holding time (day).

Fig. 13 is a graph showing the change in non-methane hydrocarbon concentration (ppm) with retention time (hour).

Figure 14 is a schematic diagram showing air cleaning in a conventional clean room.

(Embodiment of the invention)

The semiconductor substrate transport box of the present invention has an opening / closing mechanism that allows a semiconductor substrate to be stored in or taken out of the box, and a gas purifying apparatus using photoelectrons and photocatalysts by irradiating light for cleaning the inside of the box. (Gas purification unit), which can be removed from the box as appropriate.

The gas purifier is used between the original use of the box as a transport Power supply device installed in a load port, a stand-by place where a process is waiting, or a stocker, etc., receives power supply and operates, thereby allowing the gas in the box containing the substrate to be stored. Is performed.

In addition, the semiconductor substrate transport box of the present invention has an opening and closing mechanism for storing and unloading the semiconductor substrate in and out of the box, and performs gas cleaning using photoelectrons and photocatalyst by light irradiation for cleaning the inside of the box. And a power supply unit with a battery-equipped charging function to supply power to the device, and they are integrated (gas cleaning unit), and the unit is removed from the box as appropriate. You can do it.

Further, the unit may be provided with a radiator for transmitting heat generated from the power supply device to a gas cleaning device using photoelectrons and photocatalysts.

These boxes of the present invention can house, transport, and / or store a semiconductor substrate, and any box that can be hermetically sealed may be used. For example, it is made of metal or synthetic resin. Of these, A1 is preferable because of its light weight. In the case of a synthetic resin, any material may be used as long as it is excellent in processability, rigidity, and durability, and generates little gas. However, a transparent material is more preferable. For example, there are general-purpose plastics such as ABS and acryl, engineering plastics such as polycarbonate (PC), and super-engineering plastics such as polyetherimide.

The box opening / closing mechanism is any of the above-mentioned hermetically sealable boxes in which a gas purifying device using a photoelectron and a photocatalyst of the present invention described below can be installed, as long as the substrate can be appropriately stored and taken out. good.

For example, the box opening / closing mechanism consists of a box door, a wafer presser, and a sealing material, and is integrated. The box door is engaged with a door opener (SEMI standard), and is pulled out of the box body in the horizontal direction. By pulling down in the direction, the box door is opened from the box body. Examples of such boxes include: 1) a horizontal open integrated transport box, and 2) an open cassette storage type, based on the position of the opening / closing door and the type of board storage (whether or not to store the board in an open cassette). Side-open transfer box, 3) Open cassette storage type There is a bottom-open transfer box.

Next, a gas purifier using a photoelectron and a photocatalyst, which can be appropriately removed from a box having the opening and closing mechanism, which is a feature of the present invention, will be described.

By installing the device in one part of the box, the contaminants in the box are effectively removed by the gas flow (natural circulation) utilizing the heat generated in the device.

First, the structure of the photoelectron cleaning device will be described.

The cleaning device using photoelectrons is composed of a photoelectron emission material, an ultraviolet lamp, an electrode material for an electric field for photoelectron emission, and a charged particle collection material, and removes fine particles (particulate matter).

The photoelectron emitting material may be any material that emits photoelectrons when irradiated with ultraviolet light, and the smaller the photoelectric work function, the better. From the viewpoint of effect and economy, Ba, Sr, Ca, Y, Gd, La, Ce, Nd, Th, Pr, Be, Zr, Fe, Ni, Z n, Cu, Ag, Pt, Cd, Pb, A1, C, Mg, Au, In, Bi, Nb, Si, Ti, Ta, U, B, Eu , Sn, P, or W, or a compound or alloy or a mixture thereof, and these are used alone or in combination of two or more. As the composite material, a physical composite material such as amalgam can be used. For example, the oxide as a compound, boride, there is a carbide, the oxide B a 0, S R_〇, C a O, Upsilon ₂ 〇 _{_{_{5, Gd 2 0 3, N}}} d 2 0 3, T h0 2 , Z R_〇 _{_{2, F e 0 3, Z}} n O, C uO, A g 2 O, L a 2 0 3, P _{T_〇, P b O, A 1 2} Oa, Mg_〇, I n ₂ 0 ₃ , B i O, Nb_〇, include B e O, the Mataho of compounds _{_{ΥΒ β, G d B e,}} L a B 5, N d B β, C e B β, E u B 6, P r B _beta, include Z r B _2, still carbides UC, Z r C, T a C, T i C, NbC, WC, etc.

Examples of the alloy include brass, bronze, phosphor bronze, an alloy of Ag and Mg (Mg is 2 to 20 wt%), an alloy of Cu and Be (Be is l to 10 wt%). ) And an alloy of Ba and A 1 can be used, and the alloy of Ag and Mg, the alloy of Cu and Be, and the alloy of Ba and A 1 are preferable. Oxides can also be obtained by heating the metal surface alone in air or by oxidizing it with chemicals.

As another method, it is possible to form an oxide layer on the surface by heating before use to obtain a stable oxide layer over a long period of time. As an example, an oxide film can be formed on the surface of an alloy of Mg and Ag in water vapor at a temperature of 300 to 400 ° C. It is stable over time.

In addition, a substance that emits photoelectrons can be used in addition to another substance. As an example of this, there is a material in which a substance capable of emitting photoelectrons is added to an ultraviolet-transparent substance (Japanese Patent Publication No. 7-93098, Japanese Patent Application Laid-Open No. 424/340).

There is integration with an ultraviolet source described later, for example, addition of a photoelectron emitting material to the surface of an ultraviolet lamp (Japanese Patent Application Laid-Open No. Hei 4-224350). It is preferable depending on the type of application box because it becomes compact by integration.

As another example, there is integration with a photocatalyst described later (Japanese Patent Application No. 8-1332563). The integration stabilizes the simultaneous removal of gaseous harmful components coexisting with the fine particles and the self-cleaning of the photo-emissive material, which is especially effective when used in a box with a large amount of gas.

As will be described later, the shape and structure of the photoelectron emitting material differ depending on the shape and structure of the device (unit) or the desired effect, and can be determined as appropriate.

The irradiation source for emitting photoelectrons from the photoelectron emitting material may be any source that emits photoelectrons upon irradiation, and ultraviolet light is usually preferred.

The type of ultraviolet light may be any as long as the photoelectron emitting material emits photoelectrons by irradiation. Any ultraviolet ray source can be used as long as it emits ultraviolet rays, but a mercury lamp, for example, a germicidal lamp is preferable in terms of compactness.

Next, the positions and shapes of the ultraviolet light source, the photoelectron emitting material, the electrode, and the charged particle collecting material, which are features of the present invention, will be described. These are characterized in that they are installed around an ultraviolet light source, together with a photocatalyst described later as appropriate, depending on the required performance, and are integrated as a unit (unit) for purifying gases containing harmful gases and fine particles.

The position and shape of the photoelectron emitting material may be any as long as they can be installed so as to surround the ultraviolet light emitted from the ultraviolet light source (to increase the irradiation area). Normally, ultraviolet rays from an ultraviolet ray source are radially emitted in the radial direction. Therefore, it is sufficient if the ultraviolet rays can be installed in the circumferential direction so that the ultraviolet rays are emitted.

It is effective to emit photoelectrons from the photoelectron emitting material by irradiating with ultraviolet light in an electric field. Any position and shape of the electrode can be used as long as an electric field (electric field) can be formed between the electrode and the photoelectron emitting material. The electrode material and its structure may be those used in a well-known charging device. Any electrode material can be used as long as it is a conductor, examples of which include tungsten, SUS, or Cu-Zn wires, rods, nets, and plates. One or a combination of two or more of these is installed so that an electric field can be formed in the vicinity of the photoelectron emitting material (Japanese Patent Application Laid-Open No. Hei 2-33557).

The collection material (dust collection material) for charged fine particles is generally an electrode material such as a dust collection plate and a dust collection electrode in a normal charging device, and an electrostatic filter system. However, a steel wool electrode and a tungsten wool electrode are used. A wool-like structure such as described above is also effective. Electrec materials can also be suitably used.

The photoelectron emission electrode can also serve as a dust collecting material (Japanese Patent Publication No. 8-211), the preferred combination of photoelectron emission material, electrode material, and material for collecting charged fine particles is box shape. It can be determined as appropriate according to the structure, required performance, economics, etc., as long as it can quickly move contaminants such as fine particles present in the cleaning space described later into the purification device by installing in the space. good. The position and shape of the photoelectron emitting material and the electrode surround the ultraviolet light source, the ultraviolet light source, the photoelectron emitting material, the electrode, and the charged particle collecting material can be integrated, and the ultraviolet light emitted from the ultraviolet light source is effectively used, and It can be determined by a preliminary test or the like in consideration of the shape, effect, economy, etc. of the box so that the emission of particles and the charging and collection of the fine particles by the photoelectrons can be performed effectively. For example, when a rod-shaped (cylindrical) ultraviolet lamp is used, ultraviolet rays are emitted radially in the radial direction. Therefore, the more the radial radial ultraviolet rays are applied to the photo-emitting material as much as possible, the larger the amount of photoelectron emission. Increase.

Next, a cleaning device using a photocatalyst will be described.

The photocatalyst removes gaseous harmful components, and is excited by light irradiation from a light source, and causes organic gases (non-methane hydrocarbons, H.C) involved in increasing the contact angle to participate in increasing the contact angle. Any material may be used as long as it can be decomposed into a form that does not affect it or converted into a stable form that has no effect even if attached.

Generally, semiconductor materials are preferred because they are effective, readily available, and have good workability. In terms of effects and economics, S e, G e, S i, T i, Z n, C u, A 1, S n, G a, In, P, As, S b, C, C d , S, Te, Ni, Fe, Co, Ag, Mo, Sr, W, Cr, Ba, or Pb, or a compound, alloy, or oxide thereof. Preferably, these are used alone or in combination of two or more.

For example, the elements are Si, Ge, Se, and the compounds are A1P, A1As, GaP, A1Sb, GaAs, InP, GaSb, I n As, In S b, C d S, C d S e, Z n S, Mo S ₂ , WT e ₂ , Cr ₂ T e ₃ , Mo Te, Cu ₂ S, WS ₂ , the oxide T i 〇 _{_{_{2, B i 2 0 3,}}} C u O, C u 2 0, Z n O, Mo_〇 _{3, I n Oa, A g} O, P b O, S r T i 〇 ₃ _{, B a T i 0 3,} C o 3 〇 _4, F e 0 _3, N I_〇 the like.

Depending on the application destination, the photocatalyst can be formed on the metal surface by firing the metal material. An example of this was calcined for T i material, touch light effect formation of T i 〇 ₂ on the surface thereof There is a medium.

The photocatalyst is characterized by being installed around a light source similarly to the photoelectron emitting material, and integrated as a gas cleaning device (unit). Further, depending on the required performance, it can be integrated with the above-described cleaning device using photoelectrons, which is a feature of the present invention.

That is, the installation position of the photocatalyst in the gas cleaning device includes a method of installing the photocatalyst emitting material integrally and a method of separately installing the photoelectron emitting material. For example, (1) direct addition to an ultraviolet lamp, (2) an ultraviolet source is surrounded by a vitreous substance or a glass material and applied to the surface of the vitreous substance, (3) circumferential direction facing the ultraviolet source (4) coating the photocatalyst with a suitable material such as plate, cotton, mesh, honeycomb, membrane, cylinder, or fiber, or wrapping or sandwiching the photocatalyst inside the device It may be used by fixing to. An example is the coating of titanium dioxide on a glass plate by the sol-gel method. The photocatalyst can be used in the form of a powder, but can be used in an appropriate shape by a known method such as sintering, vapor deposition, sputtering, coating, or baking.

These can be appropriately selected depending on the shape of the box, the type and shape of the light source, the type of the photocatalyst, the desired effect, economy, and the like. Further, in order to improve the photocatalytic activity, in the photocatalyst P t, A g, P d , R u 0 2, C o 3 0 4 of such substances can also be used in addition. The addition of the substance is preferred because the photocatalysis is accelerated. These can be used alone or in combination.

Well-known means such as an impregnation method, a photoreduction method, a sputter deposition method, and a kneading method can be appropriately used for the addition method.

As a light source for light irradiation, any light source that emits a wavelength that is absorbed by the photocatalyst material may be used. Light in the visible, ultraviolet, or ultraviolet region is effective, and a known light source can be appropriately used. For example, mercury lamps include germicidal lamps, black lights, fluorescent chemical lamps, and UV-B UV lamps. When removing gaseous harmful components only, a visible light source can be used to remove contaminants, but when integrated with the photoelectron device, the ultraviolet lamp, for example, a germicidal lamp is effective. .

A germicidal lamp is preferable because it can increase the effective irradiation light amount to the photocatalyst (irradiation in which the photocatalyst absorbs and exerts a photocatalytic action) and accelerates the photocatalytic action.

Regarding the mechanism of removing gaseous harmful components by the photocatalyst, the removal of organic gas that increases the contact angle will be described. The present invention differs depending on the type and properties of the container (wafer, glass material, etc.) and the thin film on the container. According to their research, the following can be considered.

In other words, the common fact that organic gas (H.C), which increases the contact angle of the contents of a container in a normal clean room device, is mainly high molecular weight H.C, and its structure is one CO, one COO Has a bond (has hydrophilicity). This HC can be considered as a hydrophobic substance (a C 1 C 1 part of the basic structure of HC) having a hydrophilic part (one CO, one C 一 bond).

To explain in concrete example, the organic gases increase the contact angle of the contained object surface such as a glass substrate in the usual clean room, high molecular weight C _ie ~C ₂₀ H. C, phthalates For example, higher fatty acid phenol derivative It is common for these components to have a chemical structure of — CO, which has a single C （bond (having hydrophilic character) (Air Purification, Vol. 3, Vol. 1, No. 1, pl 6-21) , 195).

These contaminating organic gases are caused by plasticizers, mold release agents, antioxidants, etc. of polymer products. The locations where polymer products are present are sources (see Air Purification, Vol. 33, No. 1, pl 6-21, 199 5).

The details of the treatment mechanism of these organic gases by the photocatalyst are unknown, but can be estimated as follows. In other words, in these organic gases, the 1C〇 and 1C〇〇 bonds are hydrogen-bonded to the OH groups on the wafer or glass surface, and the upper surface becomes a hydrophobic surface. As a result, the wafer or glass surface becomes hydrophobic. And the contact angle increases, When formed, the adhesion of the film is weak.

In other words, when the photocatalyst is placed in an atmosphere in which an organic gas is present, the photocatalyst has an adsorbing action, so that H.C is the active portion of the photocatalyst and the COC bond is adsorbed on the photocatalyst surface, Acted upon and converted to another stable form. As a result, the organic gas is considered to be in a stable form (converted to low molecular substances) and not adhere to the wafer or glass substrate, or not to exhibit hydrophobicity even if adhered. The photocatalyst is effective not only for decomposing and removing H.C but also for removing a basic gas (hazardous gaseous component) such as ammoniaamine.

The gas cleaning in this box can be performed by a combination of photoelectrons and photocatalysts depending on required performance, economy, and the like, which is a feature of the present invention. That is, when both the fine particles and the gaseous harmful components are problematic, a cleaning device in which photoelectrons and photocatalysts are integrated can be used.

In the present invention, by installing the above-described cleaning device (unit) in the box, dust or gas generated in the box is removed. That is, this box is a box having a self-cleaning function.

The box of the present invention is integrated with a unitary gas purifying device using the above-mentioned photoelectric and photocatalyst, which can be easily attached or detached, and is operated by being connected to a power supply device for cleaning. Alternatively, the power supply device with a charging function equipped with a battery and the cleaning device are integrated, and mounted and cleaned as a gas cleaning unit, which is a feature of the present invention.

First, FIG. 4 shows a schematic block diagram of the connection between the gas cleaning device of the present invention and the power supply device, which will be described next.

The box 10 (corresponding to box 21 described later) of the present invention is provided with a gas cleaning device A _-2 using a photoelectron and a photocatalyst. Here, the box 10 is integrated with the gas purifier A- ₂ .

The box of the present invention is used for transporting substrates (carrier). Since the ratio of the residence time at the load port, the process waiting standby place, and the storage force other than the transport is large, the gas purifier A _-2 uses the load port and the process wait other than the transport. The power from the power supply 13 in the power supply device 14 installed at the location and the storage power is supplied, and the gas in the pox 10 is cleaned. That is, the box 10 of the present invention, in which the gas purifying device A _-2 is integrated, has a power supply device 14, for example, a mouthpiece of a semiconductor processing device, a process waiting state, during a transfer. The box is cleaned by being installed in a standby place, a stocker, or the like, and receiving power supply as described above.

As a result, the gas inside the box is cleaned during the standby time of the box (temporary installation, installation at night, etc.) using the aforementioned photoelectrons and photocatalysts. An ultra-clean space is created.

Next, the integration of the gas cleaning device and the power supply device of the present invention will be described with reference to a schematic block diagram shown in FIG.

The box 10 of the present invention is provided with a power supply device Α- _{: ι} equipped with a battery and a charging function, and a gas cleaning device A _-2 using a photoelectron and a photocatalyst. Here, the power supply unit A and the gas purifier A _-2 are integrated (gas purifier unit, A :). That is, the power supply device A- _{: l} is composed of a power supply 13 for supplying power to the charging circuit 11, the battery 12, and the gas purifying device A, and a power supply device (power supply station) 14 as appropriate. And the battery 12 is charged via the charging circuit 11. The box of the present invention is used for transportation (carrier), and the gas purifier A- ₂ during transportation is provided with the power supply 1 for the power charged in the battery 12 in the power supply A as described above. Continuous operation with supply from 3. The battery-12 may be any battery that can be charged and can appropriately supply power. Examples thereof include a Li-ion battery and a Ni-hydrogen battery.

The box 10 of the present invention, in which the gas cleaning unit A is integrated, is provided with a power supply device 14, for example, a load port of a semiconductor processing device, or a standby state during a process, during the transportation. It is installed in a place stocker or the like, and receives power from the battery 12 as described above.

Thereby, in the box, the gas cleaning using the photoelectrons and the photocatalyst is performed while the box is being transported or in a standby state, that is, continuously, so that an ultra-clean space is maintained in the box.

Next, utilization of heat generated from the power supply device A-: L, which is a feature of the present invention, will be described. In the power supply A-, there are electronic components (eg, power transistors and power FETs) that generate a lot of heat when used, and electronic components that generate a little heat. This is transmitted to the gas purifying device A- ₂ to promote the gas flow. This will be described with reference to FIGS. 6 (a) and 6 (b).

First, FIG. 6A will be described. 6 (a) shows a gas purifier A. ₂ wall adjacent to the electronic components and the power supply device disposed in the power supply device A.! In.

The heat generated from the electronic components 15 generated by the operation is transmitted to the wall 17 of the gas purifier A- ₂ via the radiator plate 16 (the cleaning space of the plate electrode 30 or the light shielding material 35 described later). (Corresponds to Part B). Reference numeral 18 denotes a heat conductive sheet for efficiently transmitting the heat. For 18, the heat conductive grease and epoxy resin adhesive can be used in addition to the sheet.

Here, the heat radiating plate 16 may be any material as long as it efficiently transmits heat, and examples thereof include Cu and A1. Usually, A 1 is preferred because of its light weight and relatively low cost.

Reference numeral 19 denotes an electronic component which is provided on the printed circuit board 20 and generates little heat. In this way, heat generated from the electronic component 15 that generates a large amount of heat is transmitted to the wall surface of the gas cleaning device A- ₂ . By effectively utilizing the heat, the gas circulation in the device A- ₂ is accelerated, so that the inside of the box is effectively cleaned.

The cleaning of the gas of the present invention is essentially gentle because it is caused by the flow of gas caused by heat generated from a light source such as an ultraviolet lamp. This is effective because the flow of gas is accelerated by utilizing the heat generated from the gas.

Next, FIG. 6 (b) will be described.

FIG. 6 (b) shows a case where the heat radiating plate 16 is directly installed inside the gas cleaning device via the wall surface 17.

In FIG. 6 (b), the same symbols as those in FIG. 6 (a) represent the same meanings.

The present invention can be similarly used in various gases such as N ₂ and Ar, including air in a normal clean room.

This box can be used not only for transportation but also as a stock box (storage force) since a clean space can be continuously obtained by power supply, which is a feature of the present invention. Depending on the type of box and the required performance, it is possible to install a heating source such as a lamp or a lamp inside to accelerate the gas flow. The installation accelerates the removal of pollutants, so that it can be used as appropriate.

The gas purifying apparatus or gas purifying unit of the present invention should be integrated into a box by using a well-known joining method such as through a gas-free packing material or by using a magnet (magnetic force). Can be.

(Example)

Next, examples are shown, but the present invention is not limited to these examples.

Example 1

The wafer transfer box 21 in the semiconductor factory will be described with reference to FIG.

Figure 1 shows a horizontal opening integrated transport box.

In semiconductor factories, high-quality products are manufactured in class 1,000 clean rooms. Since the wafer 22 is processed (deposited, etc.) into a high-quality (miniaturized, precise) product, it is affected by gaseous substances and fine particulate matter (fine particles).

In other words, in addition to H.C introduced from the outside air as a gaseous harmful component, clean room of class 1,000 also contains non-gas due to degassing from clean room components and equipment. Methane hydrocarbons are present at 1.1 to 1.5 ppm. On the other hand, workers also generate contaminants (gaseous substances, fine particles), so the vicinity of people is a dirty environment for wafer 22.

For this reason, the wafer 22 is stored in the wafer transfer box 21 and transferred to each process (eg, a film forming process) to be processed into a high-quality product.

The opening / closing mechanism of the box 21 is composed of a box door 23, a wafer holder 24, and a sealing material 25, and is integrated. The box door 23 is engaged with a door opener (not shown, SEMI standard). The box door 23 is released from the box body 21 by pulling it downward after pulling it out horizontally from the box body.

In the box 21, the automatic transfer robot for clean room holds the robot flange 26, and is placed on the load port of the semiconductor processing equipment. Each sheet is loaded and unloaded. After the box doors 23 are closed, they are transported again to the next process equipment by the automatic transport robot for clean room.

The box 21 includes an ultraviolet lamp 27, a photocatalyst 28, a photoelectron emission material 29, an electrode 30 for emitting photoelectrons from the photoelectron emission material (lattice or net shape), and a material for collecting charged fine particles 31. Gas purifier A is installed.

The power supply from the power supply for the operation of the cleaning device A _-2 is supplied from an external power supply device as shown in FIG. 4 described above, and the air purification in the box 21 is performed by the device A _-2 .

Since the device A _-2 is supplied with power from the power supply device installed at the outlet port, cleaning is performed for a long time (clean space is maintained).

In other words, the box 21 contains hydrocarbons (H.C) as gaseous harmful components (hazardous gases) that increase the contact angle of the wafer when attached to the wafer 22 and the wafer. If they adhere, they cause disconnections and short circuits, causing defects and the presence of fine particles that reduce the yield. These contaminants enter the box 21 from the clean room each time the box 21 is opened and closed for storing and removing the wafer 22 from and into the box 21.

Here, the H.C is decomposed by the photocatalyst action of the photocatalyst 28 irradiated with ultraviolet rays from the ultraviolet lamp 27, and is converted into a form that does not increase the contact angle. The fine particles (particulate matter) are charged by the photoelectrons 33 emitted from the photoelectron emitting material 29 irradiated with the ultraviolet lamp 27 to become charged fine particles, and the charged fine particles serve as a collecting material for the charged fine particles. The cleaning space B, which is collected by the electrode 31 and in which the wafer 22 exists, is ultra-cleaned. Movement to H. C and a gas cleaning system A _-2 of particles in the box, slight temperature above and below the gas cleaning device A in _-2 caused by irradiation of ultraviolet lamps 2 7 in the apparatus A _-2 Due to the air flow (34 34 _{-6 in} Fig. 1) caused by the difference.

Here, the box material is made of PC, UV lamp germicidal lamps (2 54 eta m), intended photocatalyst obtained by adding T i 〇 ₂ to A 1 material, as the light emission material obtained by adding Au to A 1 material The electrode for photoelectron emission is reticulated SUS (10 V / cm), and the charged fine particle trapping material is SUS (500 VZcm).

In FIG. 1, reference numeral 35 denotes a light-shielding material, which prevents irradiation of the wafer 21 with ultraviolet rays from the ultraviolet lamp 27. Reference numeral 36 denotes a partition plate for effectively flowing the flow of air _34- _: _{134-6 due} to the irradiation of ultraviolet rays to the vicinity of the wafer. In this way, the harmful gases and particulates in the air in Box 21 are treated, and the air in Box 21 does not increase the contact angle when a substrate such as a wafer is stored, and it is more effective than Class 1. An ultra-clean space is maintained. Since the contact angle of a substrate such as a wafer does not increase, when the film is formed on the surface of the substrate, there is an effect that a strong adhesive force can be formed (for example, H.C concentration: 0.1 ppm or less, NH ₃ concentration: The result was less than 1 ppb). The gas cleaning device A can be separated from the cleaning space B of the box in which the wafers are stored, and they are joined via packing material.

The disconnection is performed at the time of regular maintenance, for example, once a year.

This facilitates maintenance and management of the container in the cleaning space (B) where the wafers are stored in the box and the gas cleaning device (A _-2 ).

Reference numeral 37 denotes a kinematic coupling having a V-groove for box positioning.

Example 2

FIG. 2 shows another type of box of the wafer transfer box 21 shown in FIG. 1 of the first embodiment. FIG. 2 shows an open cassette storage type horizontal opening transfer box in which an open cassette 38 holding a wafer 22 is stored in the box of FIG. In the opening / closing mechanism of this box, since the wafer 22 is held by the open cassette 38, there is no wafer holder (24 in FIG. 1). In FIG. 2, the same reference numerals as those in FIG. 1 have the same meaning.

Example 3

FIG. 3 shows another type of box of the wafer transfer box shown in FIG. 1 of the first embodiment. FIG. 3 shows an open cassette storage type bottom-opening transport box. The box 21 has a box 21 opening and closing mechanism including a box door 23 and a sealing material 25 at the bottom thereof.

That is, the box 21 is a bottom-open box, and the opening / closing mechanism including the box door 23 and the sealing material 25 of the box 21 is lifted to the box door 23 with the box floating. The box door 23 is opened by engaging an orbner with an evening mechanism (not shown) and lowering it vertically.

The box 21 accommodates an open cassette 38 holding the wafer 22.

In FIG. 3, the same symbols as those in FIG. 1 have the same meaning. Example 4

A wafer transfer box integrated with a cleaning device for removing harmful gases and fine particles shown in Fig. 1 was installed in a semiconductor factory of class 100, and the following sample gas was charged, and ultraviolet irradiation was performed. The contact angle on the wafer stored in the wafer transfer box, the concentration of fine particles in the box, and the concentration of non-methane hydrocarbon were measured.

Here, the power supply to the power supply device was performed by connecting the power supply device to the power supply device of the storage power in the clean room.

1) Transport box size: 35 liters, manufactured by P.C.

2) Cleaning equipment

(1) UV light source: germicidal lamp 4W.

(2) a photocatalyst material; the AI board, adds T i 0 ₂ by a sol-gel method.

(3) Photoemission material; Au is added on A1 plate.

(4) Electrode for photoelectron emission; Lattice S US material, 20 V / "cm.

(5) Collector for charged fine particles (electrode plate); SUS plate, 800 V / cm.

3) Sample gas (inlet)

Medium gas: air,

Fine particle concentration: Class 1, 0 0 0,

Non-methane hydrocarbon concentration: 1.5 ppm

4) Wafer; 1 2 inch 1 3 pieces

5) Measuring instrument

Contact angle measurement; water drop contact angle meter

Particle concentration measurement; Light scattering particle counting Yuichi (> 0.1 zrn) Non-methane hydrocarbon concentration measurement; Gas chromatograph

Incidentally, particle concentration (class) shows a 0.1 total number of m or more fine particles contained in 1 ft ^3. (1) Contact angle on wafer

Figure 11 shows the relationship between the contact angle on the wafer stored in the box and the holding time. In FIG. 11, each of the samples of the present invention is indicated by an arrow mark, in comparison, an image without an electric field for photoelectron emission is indicated by an arrow mark, an image without a photocatalyst is indicated by an arrow, and a sample without UV irradiation. Shown by-鲁-mark.

(2) Particle concentration in the box (class)

Table 1 shows the particle concentration (class) in the box after 1 hour, 2 hours, 1 day, and 1 week. For comparison, Table 1 shows the one without the electric field for photoelectron emission, the one without the photocatalyst, and the one without UV irradiation. Table 1 Numerical values: class 1 hour after 2 hours after day after week After the present invention << <<< <Set the electric field for photoemission 1000 900

None (Photocatalyst only) Photocatalyst removed <1 <<<

(Photoelectrons only) Without UV irradiation 1000 900

: Not measured

(3) Non-methane hydrocarbon concentration in the box (ppm) The evaluation was performed at the same time and at the same comparison as above, and shown in Table 2 <Table 2 Numerical values: ppm

In order to confirm the effect of removing non-methane hydrocarbons in the space on the wafer, place the wafer in the box under the above conditions and transfer the phthalate ester (D 〇 P: di-2-ethyl phthalate) on the wafer. Xyl, DBP: di-n-butyl phthalate).

Measurement method: Adhered material on the wafer exposed to air under the above conditions for 16 hours was desorbed, and the phthalate ester was measured by the GCZMS method (gas chromatography / mass spectrometry).

As a result, fluoric acid ester was detected in both the case without UV irradiation and the case without photocatalyst (photoelectron only).

On the other hand, in the case of the present invention, in which the electric field for photoelectron emission is not set (for photocatalyst In any case, no phthalate ester was detected.

Example 5

The wafer transfer pox 21 in the semiconductor factory will be described with reference to FIGS. 7 and 8 show a horizontal opening integrated type transport box, and FIG. 8 is a side view of FIG. In semiconductor factories, high-quality products are manufactured in a class 1,000 clean room. Since the wafer 22 is processed (deposited, etc.) into a high-quality (miniaturized, precise) product, it is affected by gaseous substances and fine particulate matter (fine particles).

In other words, in addition to H.C introduced from outside air, non-methane hydrocarbons caused by degassing from clean room components and equipment are 1.1 as gaseous harmful components in Class 1,000 clean rooms. ~ 1.5 ppm is present. On the other hand, since pollutants (gaseous substances and fine particles) are also generated from workers, the vicinity of a person is a dirty environment for the wafer 22.

In the box 21, an automatic transfer robot for a clean room holds the robot flange 26, and is mounted on a load boat of a semiconductor processing apparatus. Mouthpieces are diced and unloaded one by one. After the box doors 23 are closed, they are again transferred to the next-step processing device by the automatic transfer robot for clean room. The box 21 includes a gas cleaner comprising an ultraviolet lamp 27, a photocatalyst 28, a photoelectron emission material 29, an electrode 30 for photoelectron emission from the photoelectron emission material, and a material for collecting charged fine particles 31. A gas purifying unit A (AA- ₂ ) comprising a purifying device A- ₂ and a power supply unit with a charging function equipped with a battery 12 (see Fig. 5) for supplying power to the gas purifying device A is installed. ing.

The power supply device A ^ and the gas purifying device A- ₂ in the unit A are as shown in FIGS. 5 and 6 above, and the air purification in the box 21 is performed by the unit A.

The cleaning (air cleaning) by the gas cleaning device A- ₂ is performed continuously for a long time because power is supplied from the power supply device described above.

In other words, box 21 causes hydrocarbon (H.C) as a gaseous harmful component (hazardous gas) that increases the contact angle of the wafer when attached to wafer 22 and breaks or short-circuits when attached to the wafer. Therefore, there are fine particles that cause defects and lower the yield. These contaminants enter the box 21 from the clean room each time the box 21 is opened and closed for storing and removing the wafer 22 from and into the box 21.

Here, the H.C is decomposed by the photocatalyst action of the photocatalyst 28 irradiated with ultraviolet rays from the ultraviolet lamp 27, and is converted into a form that does not increase the contact angle. The fine particles (particulate matter) are charged by the photoelectrons 33 emitted from the photoelectron emitting material 29 irradiated with the ultraviolet lamp 27 to become charged fine particles, and the charged fine particles serve as a collecting material for the charged fine particles. The cleaning space B, which is collected by the electrode 31 and in which the wafer 22 exists, is ultra-cleaned. The transfer of H.C and fine particles in the box to the gas cleaning device A- ₂ is performed by irradiating the ultraviolet lamp 27 in the device A and generating heat from the power supply device in the gas cleaning device A- ₂ . flow of air provoked a slight temperature difference between the upper and lower by (in FIG ₇ 34 34 -β).

Here, the box material is made of PC, UV lamp germicidal lamps (2 54 η m), intended photocatalyst obtained by adding T i 0 ₂ to A 1 material, photoemission material was added to A u to A 1 material The electrode for photoelectron emission is mesh SUS (10 V / cm), charged fine particles The child collecting material is SUS (500 VZ cm).

In FIG. 7, reference numeral 35 denotes a light-shielding material, which prevents irradiation of the wafer 21 with ultraviolet rays from the ultraviolet lamp 27. Reference numeral 36 denotes a partition plate for effectively flowing the air flow 3434- _β due to the ultraviolet irradiation and the heat generated from the power supply device in the vicinity of the wafer.

In this way, the harmful gases and particulates in the air in Box 21 are treated, and the air in Box 21 does not increase the contact angle when a substrate such as a wafer is stored, and it is more effective than Class 1. An ultra-clean space is maintained. Since the contact angle of a substrate such as a wafer does not increase, it has an effect of forming a film with a strong adhesive force when formed on the surface of the substrate (for example, H.C concentration: 0.1 ppm or less, NH ₃ concentration: The result was less than 1 ppm).

The gas cleaning unit A can be separated from the cleaning space B of the box containing the wafers, and they are joined via a packing material.

This facilitates maintenance and management of the container in the cleaning space (B) and the gas cleaning unit (A) in the box.

37 is a kinematic coupling having a V-groove for box positioning.

Example 6

FIG. 9 shows another type of box of the wafer transfer box 21 shown in FIGS. 7 and 8 of the fifth embodiment. FIG. 9 shows an open cassette storage type horizontal opening transfer box in which an open cassette 38 holding a wafer 22 is stored in the box shown in FIGS. In the opening and closing mechanism of this box, the wafer 22 is held by the open cassette 38, so there is no wafer holder (FIG. 7). In FIG. 9, the same symbols as those in FIGS. 7 and 8 have the same meaning.

Example 7 FIG. 10 shows another type of the wafer transfer box shown in FIGS. 7 and 8 of the fifth embodiment. FIG. 10 shows an open cassette storage type bottom-opening transport box. The box 21 has a box door 23 and a box 21 opening / closing mechanism made of a sealing material 25 at the bottom thereof.

That is, the box 21 is a bottom-open box, and the opening / closing mechanism including the box door 23 and the sealing material 25 of the box 21 is lifted to the box door 23 with the box floating. The box door 23 is opened by engaging the evening mechanism opener (not shown) and lowering it vertically. The box 21 accommodates an open cassette 38 holding the wafer 22.

In FIG. 10, the same symbols as those in FIGS. 7 and 8 have the same meaning.

Example 8

A wafer transfer box with the configuration shown in Fig. 7 was installed in a semiconductor factory of class 1, 000, and a cleaning device for removing harmful gases and particulates shown in Fig. 7 and a cleaning device shown in Figs. A gas purifying unit consisting of a battery-equipped power supply unit with a charging function for supplying voltage to the device with the above configuration is installed, the following sample gas is charged, ultraviolet irradiation is performed, and the device is stored in the wafer transfer box The contact angle on the wafer, the concentration of fine particles in the box, and the concentration of non-methane hydrocarbons were measured.

Here, the power supply to the power supply device was performed from a power supply device with a tough force in the clean room.

1) Transport box size: 35 liters, manufactured by P.C.

2) Cleaning equipment

(1) UV source; germicidal lamp 4W.

(2) a photocatalyst material; to A 1 on the plate, adding T i 〇 ₂ by a sol-gel method.

(3) Photoelectron emission material; Au is added on A1 plate.

(4) Electrode for photoemission; lattice-shaped SUS material, 20 VZcm. (5) Collection material for charged fine particles (electrode plate); S US plate, SOO VZc nu 3) Power supply device

(1) Charging circuit; A device equipped with a voltage monitor circuit to charge the battery under optimal conditions.

(2) ノ, ッテリ一; Li-ion battery.

(3) Power supply; voltage required for cleaning device (for lighting sterilization lamp: 20 ~

DC-DC converter and DC-AC converter to supply AC voltage of 50 kHz, for electrodes for photoemission; DC 100 V, for collecting charged particulates: DC 1, 000 V) The one with.

(4) Heat-producing electronic components used to accelerate air circulation;

DC-DC converter, DC-Power transistor and power FET used in AC converter and charging circuit.

(5) Heat sink; A1 plate (thickness: 2 mm)

4) Sample gas (inlet)

Medium gas: air,

Fine particle concentration: Class 1, 0 0 0,

Non-methane hydrocarbon concentration: 1.5 ppm

5) Wafer; 12 inch 1 3 pieces

6) Measuring instrument

Contact angle measurement; water drop contact angle meter

Particle concentration measurement; Light scattering particle counter (> 0.1m) Non-methane hydrocarbon concentration measurement; Gas chromatograph

The particle concentration (class) indicates the total number of fine particles of 0.1 Aim or more contained in 1 fta.

result (1) Contact angle on wafer

Figure 12 shows the relationship between the contact angle on the wafer stored in the box and the holding time. In FIG. 12, the one of the present invention is indicated by an arrow, the comparison is without an electric field for photoelectron emission, and the one without the photocatalyst is the one without bite, and the one without UV irradiation. -Indicated by a sign.

(2) Particle concentration in the box (class)

Table 3 shows the particle concentration (class) in the box after 1 hour, 2 hours, 1 day, and 1 week. For comparison, Table 3 shows the results without the electric field for photoelectron emission, without the photocatalyst, and without UV irradiation. Table 3 Numbers: Class

Without measuring (3) Non-methane hydrocarbon concentration in box (p pm)

Evaluation was performed at the same time and at the same comparison as shown above.

In order to confirm the effect of removing non-methane hydrocarbons in the space on the wafer, the wafer was stored in a box under the above conditions, and phthalate esters (DOP, DBP) on the wafer were examined.

Measurement method: Adhered substances on the wafer exposed to air under the above conditions for 16 hours were removed, and phthalic acid ester was measured by GCMS method.

As a result, phthalate was detected in both the case without UV irradiation and the case without photocatalyst (photoelectron only).

On the other hand, in the case of the present invention, in which the electric field for photoelectron emission is not set (optical In the case of the catalyst only), no fluoric acid ester was detected in any case.

FIG. 13 shows the results of a test performed on the above-described device of the present invention with the heat sink removed. The drawing shows the relationship between non-methane hydrocarbon concentration and retention time. In FIG. 13, the one according to the present invention is indicated by an eleven-one mark, and the one obtained by removing the heat sink for comparison is indicated by a one-mark. From Fig. 13 it can be seen that the installation of the heat sink accelerates the removal rate of the cleaning device. In FIG. 13, i indicates a value below the detection limit (0.1 ppm).

(The invention's effect)

According to the present invention, the following effects can be obtained.

1) In a semiconductor substrate transport box, the box has an opening and closing mechanism, and a gas purifying device that uses photoelectrons and photocatalysts to clean the inside of the box, or a battery mounted charging device that supplies power to the device and the device. By providing a power supply with functions,

(1) The inside of the box was cleaned by a gas cleaning device, and the cleaning was performed continuously for a long time because power was supplied from the power supply device.

(2) A box that can be handled by a robot due to the opening and closing mechanism.

(3) In the installation of the gas cleaning device, the integration of the photoelectrons and the photocatalyst (simultaneous removal of fine particles and gas) could be appropriately selected depending on the type of application box, required performance, economy, and the like.

In other words, it became a practically effective cleaning system, and its application range was widened.

(4) Box (wafer storage space) Particles and harmful gaseous components in the box were effectively removed. In other words, a space that is cleaner than class 1 for removing particulates, and a clean space that does not increase the contact angle when removing gaseous harmful components.These particles and gaseous pollutants can be removed simultaneously, and the contact angle does not increase. Kula A clean space that is even cleaner than that of the first space could be easily created.

(5) Even when the power supply unit is not integrated, the residence time of the board storage box is longer than the time required for actual transfer, and is more likely to be at places other than transfer, such as load ports, stockers, and process waiting. Time is quite a lot. Therefore, by installing the power supply device in a place other than the transportation, the purification by the purification device of the present invention was rationally performed for a long time.

2) In the purifying by the gas purifying apparatus in the above 1), by transmitting heat generated by the power supply unit to the gas purifying apparatus, the flow of gas in the box is accelerated, and contaminants are removed by photoelectrons and photocatalysts. It became effective.

3) By integrating the gas purifying device in 1) above with the box, so that the gas purifying device can be removed from the box,

(1) Since the gas purifying device can be separated from the purifying space of the box, maintenance and management of the purifying space and the unit are facilitated.

(2) It can be attached not only to the box of the present invention but also to any other appropriate box, and the range of application has been expanded.

4) By the above,

(1) Naturally, contaminants that enter the box when storing and unloading the board, gas and dust generated from the board surface, and gas and dust generated from the box material are also removed. Ultra-cleaned for cleaning.

(2) As the box material, a plastic material which is likely to generate gas can be used. Plastic is light and effective in practice.

(3) Since the power is supplied from the power supply unit and the cleaning is performed continuously (maintaining an ultra-clean space), it can be suitably used as a stock box (storage force). (4) The box is practically effective and can be used as a box for transporting substrates in a wide range of fields.

(5) The range of application has been expanded, and practicality has been improved. (6) In the future, semiconductors will continue to increase in quality, miniaturization, and precision, and at the same time, their substrates will increase in size, and the use of robot-to-substrate storage boxes will be indispensable. It can be suitably used as a substrate storage box (for transport and stock).

Claims

The scope of the claims

1. A semiconductor substrate transport box having an opening / closing mechanism that allows a semiconductor substrate to enter and exit, wherein the box includes a gas purifying device that integrates a gas purifying device that uses photoelectrons and photocatalysts by irradiating light to clean the inside of the box. A transfer box for semiconductor substrates, characterized by having a unit.

2. In a semiconductor substrate transport box having an opening / closing mechanism capable of moving a semiconductor substrate in and out, a gas purifying device using photoelectrons and a photocatalyst by irradiating light for cleaning the inside of the box, and a power supply to the device. A transfer box for semiconductor substrates, characterized by having a gas purifying unit that integrates a power supply unit with a charging function with a battery to be supplied.

3. The transfer box for a semiconductor substrate according to claim 1, wherein the transfer box is made of a synthetic resin.

4. The transfer box for a semiconductor substrate according to claim 2, wherein the gas cleaning unit includes a radiator for transmitting heat generated in a power supply device to the gas cleaning device.