JP2000043976A - Precision substrate storage container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a precision substrate storage container which effectively protects a precision substrate being received and stored against organic contamination and can keep cleanliness of the precision substrate for a long term. SOLUTION: The storage container 1 comprises a synthetic resin container body 2 for storing semiconductor wafers in an array and a synthetic resin lid 4 for sealably covering an opening of the container body 2 via a gasket 3. A photocatalyst layer 19 is detachably held in a pressing member 14 in the lid 4. The lid 4 is made to be transparent, and a transmission region 20 for leading ultraviolet rays from above the exterior of the storage container 1 into the photocatalyst layer 19 is provided. Since the photocatalyst layer 19 effectively decomposes organic substances, organic constituents attaching to the semiconductor wafers are reduced. Therefore contamination of the semiconductor wafers can be effectively prevented, and a space with high cleanliness can be maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved precision substrate container for transporting and storing precision substrates such as semiconductor wafers and photomasks.

[0002]

2. Description of the Related Art Precision substrate storage containers used for transporting and storing precision substrates such as semiconductor wafers and photomasks are not shown in the figure, but are considered in terms of overall performance such as lightness, various performances, and cost. And polypropylene, polycarbonate, polybutylene terephthalate,
Alternatively, injection molding is performed using a synthetic resin represented by various other elastomers.

[0003] This type of precision substrate storage container is composed of a transport container or a shipping box used when transporting precision substrates from a wafer maker to a device maker, and process contents used when transporting or storing between processes in a device maker. It is roughly divided into equipment. These contain precision substrates in the container body and seal the opening of the container body with a lid.
It covers and blocks the outside air, and particles (par
(ticle), organic matter, or metal components, and functions to maintain the cleanliness of the precision substrate. These are all sealed by various methods when the precision substrate is stored in the container body.

For example, in the case of the former shipping box, a tape is wound around the outer periphery of a fitting portion between the container body and the lid, or the lid is fitted to the container body via a gasket made of an endless elastic body. The sealing method to be combined is often used. In the case of the latter process containers, a sealing method using a gasket is adopted. In recent years, in the mini environment system (mini environment: local cleaning environment), an in-process transfer container called a pod (Pod) that has a mechanical interface function with semiconductor manufacturing equipment typified by handling equipment etc. is introduced. However, a sealing method in which a lid is fitted to the container body via a gasket is also used for the in-process transfer container.

[0005] By the way, the inside of the precision substrate storage container is closed when the precision substrate is stored as described above.
Organic components that ooze out and evaporate over time from the synthetic resin adhere to the precision substrate, causing a problem of contamination of the precision substrate. In order to cope with this problem, conventionally, a method of modifying a synthetic resin to reduce volatile organic components has been adopted.
(In this regard, see Japanese Patent Application Laid-Open No. 8-250581).
In the case of an in-process transfer container such as a pod, a gas inlet / outlet is provided in the container main body, and the inside of the container main body is replaced with an inert gas such as nitrogen, thereby preventing oxidation of the precision substrate and preventing the precision substrate from being oxidized. A mechanistic method of reducing the adhesion of organic components has been adopted (in this regard, US Pat. No. 4,724,8).
No. 74).

As related prior art documents of this kind,
JP-A-6-63379, JP-A-6-204196,
Or JP-A-10-37135.

[0007]

In the conventional precision substrate storage container, organic matter contamination of the precision substrate is prevented by the above-described method. However, the integration degree and the diameter of the precision substrate are increased (200 mm). Up to 300mm)
The trace amount of organic components volatilized from synthetic resin is greatly affecting the cleanliness and yield of precision substrates. Under such circumstances, even if the above method is employed, contamination of the precision substrate cannot be effectively prevented, or a space with high cleanliness cannot be secured. In addition, when the precision substrate is stored in the precision substrate storage container for a long time, contamination of the precision substrate is caused by a small amount of organic matter derived from the precision substrate storage container.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a precision substrate storage container that can effectively protect a precision substrate during storage and storage from organic contamination and maintain the cleanness of the precision substrate for a long period of time. It is an object.

[0009]

According to the first aspect of the present invention, in order to achieve the above object, a precision substrate is stored in a storage container, and a photocatalyst layer provided inside the storage container, And a transmission region for guiding ultraviolet light from outside of the storage container to the photocatalyst layer.

The storage container comprises a synthetic resin container body for storing the precision substrate, and a synthetic resin lid for sealingly covering an opening of the container body. And at least one of the lid,
The photocatalyst layer and the photocatalyst layer can be integrally formed. Further, the container body and / or the lid can be made of polytetrafluoroethylene resin. Further, the photocatalyst layer has a T
It is desirable to have a catalyst comprising one or more metal oxides selected from i, Zn, Sn, W, Bi, or Fe.

Here, the material forming the transmission region of the storage container in the claims includes, in addition to polycarbonate, a polyolefin resin such as polyethylene, polypropylene, or polymethylpentene, an acrylic resin, polystyrene, or polyvinyl chloride. Or a transparent synthetic resin such as soda glass, Pyrex glass, or quartz glass. By using these materials, the storage container is formed as a transport container, a shipping box for shipping, a carrier for semiconductor manufacturing process, or a carrier for transport between processes.

The storage container comprises a container body and a lid, but the container body may further comprise an outer box and an inner box for aligned storage. In addition, the storage container has a top open box structure in which a lid closes an upper opening of the container body,
It is formed into a front open box structure in which a lid closes the front of the opening of the container main body, or a bottom open box structure in which a lid closes the lower opening of the container main body, and is subjected to an antistatic treatment as required.

The precision substrate includes at least one (eg, 13 or 25) liquid crystal cells, quartz glass, semiconductor wafers (eg, silicon wafers) used in the field of manufacturing electric, electronic, or semiconductor devices. A mask substrate and the like are included. Large diameter when precision substrate is semiconductor wafer
(For example, 200 mm to 300 mm or more) semiconductor wafers are included. In addition, the photocatalyst layer and the transmission region may be single or plural. The positional relationship between the photocatalyst layer and the transmission region is not particularly limited as long as the ultraviolet light incident on the transmission region is directly and indirectly irradiated and reaches the photocatalyst layer. However, when the ultraviolet rays are vertically incident on the transmission region and the photocatalyst layer and the transmission region are positioned as close to each other and horizontally as possible, the effect of the photocatalyst is increased.

The photocatalyst layer is removably attached to a part or the whole of the inside of the storage container (inside the inner volume surface) by using a well-known conventional technique, or is provided integrally with the storage container. The photocatalyst layer is formed in various shapes such as a plate shape and a sheet shape. The photocatalyst layer is preferably fixed to a large surface area in the storage container from the viewpoint of the effect. However, it is desirable to avoid the part in direct contact with the precision substrate in the storage container because there is a risk of contamination. In addition, the transmission area
Considering that the photocatalytic action depends on the intensity (energy) of ultraviolet rays, the photocatalyst is provided as a part of the container using a material having a transmittance as high as possible at an ultraviolet wavelength of 400 nm or less. The transmitting region may be one that directly or indirectly guides ultraviolet light to the photocatalyst layer. When the transmission region is provided, additives such as coloring pigments and dyes are appropriately used as long as the photocatalytic action is not impaired.

According to the present invention, when ultraviolet rays are radiated to the photocatalyst layer from the outside of the storage container containing the precision substrate through the transparent region, the organic matter volatilized from the synthetic resin material forming the storage container is removed from the storage container. It is adsorbed on the surface of the inner photocatalyst layer and decomposed by photocatalysis. Therefore, the organic components adhering to the precision substrate can be reduced, the organic contamination of the precision substrate to be stored can be prevented and the cleanness of the precision substrate can be maintained.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments. As shown in FIG. 1, the precision substrate storage container according to the present embodiment is configured by a wafer transport container, and a storage container 1 for aligning and storing a plurality of semiconductor wafers W is provided with a photocatalyst layer 19 and a transmission region 20 respectively. I have.

The storage container 1 includes a translucent container main body 2 and a lid 4 which removably fits and covers the upper opening of the container main body 2 via a gasket 3. The container main body 2 includes an outer box 5 having a substantially bottomed rectangular cylindrical shape, and a carrier 6 which is an inner box removably fitted and housed in the outer box 5. Injection molding is performed using polypropylene that satisfies the requirements for low gas, low metal, low contamination such as ion elution, and mechanical properties. The outer case 5 has a thin fitting step 7 for the gasket 3 protrudingly formed on the periphery of the upper part of the opening, and locking portions 9 protrudingly formed above the outside of a pair of opposite side walls.

The carrier 6 has a pair of side walls opposed to each other. A connecting bar 10 is formed between the front sides of the pair of side walls, and a back wall 11 is formed integrally between the back sides of the pair of side walls. Alignment slots 12 having a V-shaped or U-shaped cross section are formed on the inner facing surfaces of the pair of side walls at a predetermined pitch in the front-rear direction, and the semiconductor wafers W are aligned and stored in the plurality of alignment slots 12. Each side wall is formed with a flange 13 projecting horizontally in the upper part thereof.

The lid 4 is injection-molded using polycarbonate which satisfies the requirements of low gas, low metal, low contamination such as ion elution, and mechanical characteristics, and the holding member 14 is detachable inside. It is fitted to. Polycarbonate is uncolored, has a light transmission characteristic of transmitting about 70% or more of an ultraviolet wavelength near 380 nm at a thickness of 2 mm, and has sufficient characteristics to allow the photocatalyst layer 19 to act. The lid 4 is formed such that the outer peripheral portion of the opening bulges outward, and hook pieces 15 that are locked to the locking portions 9 are formed on both sides of the outer peripheral portion of the opening so as to be deformable.

The holding member 14 has a frame 16. On both sides of the frame 16, L-shaped holding pieces 17 are formed side by side in the front-rear direction, and each holding piece 17 is attached to the upper peripheral edge of the semiconductor wafer W. To prevent rattling. As shown in FIG. 2, a pair of L-shaped support pieces 18 are formed in a protruding manner at the center of the frame body 16, and the pair of support pieces 18 detachably hold a separate photocatalyst layer 19.
The gasket 3 is injection-molded in an endless frame shape using a polyolefin-based elastomer that satisfies requirements for low gas, low metal, low contamination such as ion elution, and mechanical properties. Between the thin fitting step 7 and the outer peripheral portion of the opening of the lid 4 to maintain airtightness.

The photocatalyst layer 19 comprises a photocatalyst made of anatase type titanium dioxide which is stable and effective, and an immobilized base material made of an oxidation-resistant polytetrafluoroethylene resin which can prevent decomposition of the resin by the titanium dioxide. With titanium dioxide in the immobilized substrate, 50% by weight of the resin mixed,
The kneaded material is formed into a plate-shaped molded product having a thickness of 1 mm by rolling. Regarding the content of titanium dioxide,
From the viewpoint of the photocatalytic effect, a high content is desired so that as many titanium dioxide particles as possible are deposited on the surface. For this purpose, it is preferable to use a so-called integral skin layer in which titanium dioxide is concentrated and dispersed near the surface. However, in actuality, depending on the binder or resin used, in consideration of the mechanical strength and the holding power of titanium dioxide as a photocatalyst fixing member, in the case of a fluororesin, the weight ratio is in the range of 20% to 80%. It is desirable to mix them appropriately.

The thickness of a molded article using a fluororesin as a binder depends on whether the photocatalyst layer 19 is formed into a sheet or a plate. However, since the fluororesin is a porous body, the thickness of the porous material of the binder is low. The thickness is preferably as large as possible so that the amount of contaminants in contact with the titanium dioxide fixed to the surface is increased. Also, as the particle size of titanium dioxide,
The average primary particle size measured using X-rays is 7 nm, and the secondary particle size of aggregation is from 20 nm to 5 nm depending on conditions such as the production method.
00 nm.

[0023] Since the smaller the particle size, the larger the surface area and the ability to treat contaminants are increased,
When using titanium dioxide as a photocatalyst, it is desirable to use titanium dioxide having a particle size as small as possible within a range of 200 nm or less, preferably 100 nm or less. In particular,
In this range, the wavelength becomes smaller than the wavelength of visible light.
Since the photocatalyst layer 9 can be formed, the photocatalyst layer 19 and the transmissive region 20 can be integrally formed to be transparent by directly providing the photocatalyst layer 19 in the transmissive region 20 which is an ultraviolet light intake.

In the present embodiment, a photocatalyst made of titanium dioxide is shown, but the present invention is not limited to this. For example, a metal oxide such as titanium, zinc, tin, iron, tungsten, or bismuth, or a metal complex such as ruthenium can be used. In addition, as an immobilization substrate,
In addition to resin, inorganic materials such as metals and ceramics, paper, and the like can be used according to the application. However, in the case of an organic substance such as a synthetic resin, the organic substance itself may be decomposed by the action of the photocatalyst as described above, so that an oxidation-resistant material such as a fluororesin or a silicone resin is selected as a binder, or a photocatalyst is used. It is necessary that an inorganic protective layer or an adhesive layer is provided between the substrate and the immobilization substrate so as not to come into direct contact with the immobilization substrate. Alternatively, a photocatalyst sheet or film having a structure in which a photocatalyst is fixed to the surface of a substrate such as a sheet or a film via an adhesive layer in advance may be attached to a predetermined position on the back surface of the substrate via an adhesive layer.

Regardless of which method is employed, since the decomposition of organic substances occurs on the surface of the photocatalyst, for example, the number of photocatalyst layers 19 is increased, and the photocatalyst is fixed to a porous inorganic base material such as zeolite. By increasing the effective surface area of the photocatalyst, etc., as many photocatalysts as possible appear on the surface and increase the chances of contact with the organic substance to be decomposed, thereby increasing the effect by appropriately selecting the binder, the filling amount, the fixing method, and the like. Is preferred.

The method for immobilizing the photocatalyst layer 19 is not limited to the above-mentioned method, and various well-known methods can be employed. For example, when the immobilization substrate is a heat-resistant inorganic material, the organic titanium compound is silica, an appropriate binder such as water, and, if necessary, nitric acid, sulfuric acid, or a stabilizer such as an acid such as hydrochloric acid or a dispersant. It is possible to adopt a method in which the mixture is mixed to form a sol-like solution, which is applied to the immobilized substrate by spraying, dipping, coating, or the like, and then firing. Further, a method of spraying a paint on a preheated base material to fix the base material on titanium dioxide can also be used.

Further, as shown in FIG. 1, the transmissive region 20 comprises a transparent cover 4, particularly a flat portion thereof, and has a function of allowing ultraviolet rays to directly enter the adjacent photocatalyst layer 19 from above the outside of the storage container 1. I do.

In the above configuration, a plurality of semiconductor wafers W are aligned and stored in the carrier 6, and the carrier 6 is
The lid 4 is fitted over the upper opening of the outer box 5 via the gasket 3, and then the hook pieces 15 are
Respectively, a plurality of semiconductor wafers W can be shipped and transported in a clean state.

Further, when ultraviolet rays of 400 nm or less are radiated to the photocatalyst layer 19 through the transmission region 20 from above the outside of the storage container 1 storing a plurality of semiconductor wafers W, the surface of the photocatalyst layer 19 is irradiated by the photoelectric effect. Electrons and holes are generated respectively, and these reduce or oxidize oxygen and moisture in the air, respectively, superoxide ion (O ₂ ⁻ ),
Generates reactive oxygen species called hydroxyl radicals (.OH). And the volatile organic substance which adhered to the surface is decomposed | disassembled into carbon dioxide and water by strong oxidizing action which these have.

According to the above configuration, since the photocatalyst layer 19 effectively decomposes a small amount of organic substances at a low concentration, the organic components attached to the semiconductor wafer W are greatly reduced. Therefore,
The contamination of the semiconductor wafer W can be extremely effectively prevented, and a space with high cleanliness can be easily secured. Further, even if a plurality of semiconductor wafers W are stored in the precision substrate storage container for a long period of time, it is possible to effectively prevent contamination of the semiconductor wafer W by a slight amount of organic matter derived from the precision substrate storage container. become. Further, it is only necessary to provide the photocatalyst layer 19 and the transmissive region 20 in the storage container 1, and there is no need for a complicated device such as a power supply for operation or an electrode or any improvement work. It can be used with only a partial improvement of the shape and material without impairing the function of (1).

The photocatalyst layer 1 is irradiated with ultraviolet rays of 400 nm or less.
9 operates, so that no special light source or equipment is required, and existing equipment such as lighting in a clean room can be used as it is. Further, since the photocatalyst layer 19 and the light source are used in an independent non-contact state, the storage container 1
There is no need to provide a complicated device such as a power supply and electrodes for operation, and there is no restriction on the transportation and transportation of the storage container 1. In addition, since the photocatalyst layer 19 decomposes organic substances in the sealed state of the storage container 1, processing can be performed without affecting the external environment or affecting the throughput. Further, since the photocatalyst layer 19 can be cleaned and reused, it is possible to maintain the cleaning degree of the semiconductor wafer W for a long period of time at low energy and at low cost. Further, since the lid 4 is transparent, the contents can be easily checked.

Next, FIGS. 3 and 4 show a second embodiment of the present invention. In this case, a photocatalyst layer 19 is integrally formed on the rear wall 11 of the carrier 6. The other structural parts are the same as those in the above embodiment, and a description thereof will be omitted.

Next, a method of integrally forming the carrier 6 and the photocatalyst layer 19 will be described with reference to FIG. First, in order to fix the photocatalyst layer 19 to the back wall 11 of the carrier 6, a polytetrafluoroethylene resin is used, and 50 wt% of anatase type titanium dioxide is mixed and kneaded with the resin. A sheet having a thickness of 0.2 mm by molding, in other words,
The photocatalyst layer 19 is formed. After the photocatalyst layer 19 is formed in this way, the photocatalyst layer 19 is set on an upper portion of the back wall 11 in the cavity 22 of the injection mold 21 for forming the carrier 6, and the photocatalyst layer 19 is moved by the pressure of the filling resin. 23, and the injection mold 21 is clamped.

Then, if the polytetrafluoroethylene resin is injection-molded in the injection mold 21, the carrier 6 fused and integrated with the photocatalyst layer 19 can be obtained. In addition, polytetrafluoroethylene resin is widely used for wafer carriers and the like mainly in a cleaning process in a device process because of its chemical resistance, and is a proven material.

In this embodiment, the same operation and effect as those of the above embodiment can be expected. Further, since the carrier 6 and the photocatalyst layer 19 are integrally formed, the supporting piece of the pressing member 14 can be omitted, and the molding operation can be performed. It is obvious that simplification of the structure and simplification of the structure can easily be expected. Further, the strength of the photocatalyst layer 19 is maintained by the rigidity of the integrated carrier 6, and the strength of the photocatalyst layer 19 itself is not so much required, so that the selection range of the fluororesin as the binder is widened and the filling amount of titanium oxide is increased. This makes it possible to increase the catalytic action efficiency. As the photocatalyst layer 19 to be integrated, a photocatalyst sheet or film having a structure in which a photocatalyst is fixed to a surface of a base material such as a film via an adhesive layer is preferable.

FIG. 6 shows a third embodiment of the present invention. In this case, the container 1 of the precision substrate container is provided with a pod 24 for aligning and storing 300 mm semiconductor wafers W. The pod 24 includes a pod door 25 for detachably fitting and covering the opening front of the pod 24 via the gasket 3, and a polycarbonate bottom plate 26 mounted on the bottom surface of the pod 24. Then, a separate photocatalyst layer 19 is attached above the inside of the pod 24 via a support member (not shown), and the pod 24 is molded to be transparent to form the transmission region 20.

The pod 24 is formed in a front open box structure that can be connected to FIMS or SMIF using polycarbonate or the like, and a plurality of locking holes are formed on the upper and lower inner peripheral surfaces of the front. A rear retainer is mounted on the inner rear surface of the pod 24, and opposing substrate support supports 27 are mounted on both inner sides of the pod 24. The rear retainer and the pair of substrate support supports 27 vertically move a plurality of semiconductor wafers W. Align in the direction.

The pod door 25 is formed using polycarbonate or the like, and has a built-in opening / closing lock mechanism 28 for moving a plurality of latch plates 30 up and down based on a rotation operation of the disk 29. Each latch plate 30 of the opening / closing lock mechanism 28 is formed with a locking claw 31 that protrudes and retracts from a through-hole on the outer periphery of the pod door 25. A pod door 25 is firmly fitted and covered on the front surface of the pod door 24.

In the above configuration, when the semiconductor wafers W are stored, a plurality of semiconductor wafers W are aligned and stored in the pod 24, the pod door 25 is fitted to the opening front of the pod 24, and the opening / closing lock mechanism 28 Is locked in a pod opener (not shown), whereby a plurality of semiconductor wafers W are stored in the precision substrate storage container in an airtight state.

When it is desired to process the semiconductor wafer W, for example, a precision substrate storage container is positioned and set on a carrier stage of a handling device (not shown) together with an open cassette (not shown). Then, the pod door 25
The opening / closing lock mechanism 28 is unlocked by the pod opener, and the pod door 25 is removed from the opening front of the pod 24. Then, after confirming the storage state and the like of the plurality of semiconductor wafers W, the semiconductor wafers W are sequentially taken out from below by the transfer mechanism of the handling device, and transferred from below to the open cassette of another carrier stage.

In this embodiment, the same operation and effect as those of the above embodiment can be expected, and furthermore, it is possible to effectively prevent contamination of the large-diameter semiconductor wafer W and to secure a space with high cleanliness. Further, even if the large-diameter semiconductor wafer W is stored for a long period of time, it is possible to prevent the semiconductor wafer W from being contaminated by a small amount of organic matter derived from the precision substrate storage container.

In the above-described embodiment, the storage container 1 in which gas convection does not occur is merely shown. However, the outer box 5, the carrier 6, the lid 4, the pod 24, or a part of the pod door 25 is made of black or the like. A paint may be applied, and the gas in the storage container 1 may be convected using the temperature distribution generated by the irradiation of the ultraviolet light, so that the object to be processed of the storage container 1 is efficiently brought into contact with the photocatalyst layer 19. Further, the transparent pod 24 or pod door 25 and the photocatalyst layer 19 may be integrally formed.

[0043]

EXAMPLES Example 1 Object of Test It is checked how much the semiconductor wafer W stored and stored in the precision substrate storage container of FIG. 1 can be protected from organic contamination.

Test 1 (1) One 8-inch semiconductor wafer W immediately after cleaning was stored in the alignment slot 12 at the center of the carrier 6 constituting the precision substrate storage container of FIG. After being stored, the lid 4 was fitted to the upper opening of the outer box 5 via the gasket 3 to seal the semiconductor wafer W. (2) The precision substrate storage container was left at room temperature for 2 hours in a clean room illuminated by a fluorescent lamp having an ultraviolet intensity of 0.5 μW / cm ² . In addition, a germicidal lamp, a black light, a cold-cathode tube, or the like can be used as an ultraviolet light source depending on conditions of an environment, an apparatus, and the like. (3) Remove the semiconductor wafer W from the precision substrate storage container and analyze the organic substances desorbed from the surface of the semiconductor wafer W at a heating temperature of 400 ° C. by a commercially available thermal desorption gas chromatography / mass spectrum (GC / MS). did.

Results of Test 1 The detected organic matter was mainly composed of aliphatic hydrocarbons and BHT which is considered to be caused by additives of the resin. When the relative peak intensities of these total ion chromatographs were compared with Comparative Example 1 described later, the relative peak intensities were reduced to about 1/3 or less, and the effect was recognized.

Test 2 A pure water drop was dropped on the semiconductor wafer W, and at the point of contact with the surface of the semiconductor wafer W, as shown in FIG. Was measured, that is, the contact angle θ was measured to confirm the degree of contamination of the surface of the semiconductor wafer W. Generally, when the contact angle θ of a water droplet on the semiconductor wafer W exceeds 10 degrees,
It is considered that the hydrophobicity becomes too large and the contamination rate is high. Results of Test 2 When the degree of contamination on the surface of the semiconductor wafer W was confirmed by measuring the contact angle θ, it was about 6 degrees. Further, when the relative peak intensity of the total ion chromatograph was measured on the semiconductor wafer W immediately after cleaning by the same method as in Test 1,
No organic matter was found. The contact angle θ was 2 degrees.

Example 2 Object of Test It is checked how much the semiconductor wafer W stored and stored in the precision substrate storage container of FIG. 3 can be protected from organic contamination.

Test 1 (1) One 8-inch semiconductor wafer W immediately after cleaning was stored in the alignment slot 12 at the center of the carrier 6 constituting the precision substrate storage container shown in FIG. After being stored, the lid 4 was fitted to the upper opening of the outer box 5 via the gasket 3 to seal the semiconductor wafer W. (2) The precision substrate storage container was left at room temperature for 3 days in a clean room illuminated by a fluorescent lamp having an ultraviolet intensity of 0.5 μW / cm ² . (3) Remove the semiconductor wafer W from the precision substrate storage container and analyze the organic substances desorbed from the surface of the semiconductor wafer W at a heating temperature of 400 ° C. by a commercially available thermal desorption gas chromatography / mass spectrum (GC / MS). did.

Results of Test 1 The detected organic matter was mainly composed of aliphatic hydrocarbons and BHT which is considered to be caused by additives of the resin. When the relative peak intensities of these total ion chromatographs were compared with Comparative Example 1 described later, the relative peak intensities were reduced to about 以下 or less, and the effect was recognized.

Test 2 A pure water drop was dropped on the semiconductor wafer W, and at the point of contact with the surface of the semiconductor wafer W, the water drop
, That is, the contact angle was measured to confirm the degree of contamination of the surface of the semiconductor wafer W. Results of Test 2 The contact angle was measured to confirm the degree of contamination on the surface of the semiconductor wafer W. As a result, the degree was 8 °, indicating an effect.

The difference between the effects of Example 1 and Example 2 is presumed to be due to the difference in surface properties centering on the surface area of the photocatalyst layer 19.

Comparative Example The same test as in Examples 1 and 2 was performed on a precision substrate storage container having the same configuration as in Example 1 and without the photocatalyst layer 19. Results of Comparative Example The contact angle was 10 degrees. The amount of organic substances on the surface of the semiconductor wafer W was set to 100 as the relative peak intensity of the total ion chromatograph of the semiconductor wafer W.

[0053]

[Table 1]

[0054]

As described above, according to the present invention, there is an effect that the precision substrate during storage and storage can be effectively protected from organic contamination. Further, the cleanliness of the precision substrate can be maintained for a long time.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an embodiment of a precision substrate storage container according to the present invention.

FIG. 2 is an explanatory view of a main part showing an embodiment of a precision substrate storage container according to the present invention.

FIG. 3 is an exploded perspective view illustrating a precision substrate storage container according to a second embodiment of the present invention.

FIG. 4 is an explanatory view of a main part of a precision substrate storage container according to a second embodiment of the present invention.

FIG. 5 is an explanatory cross-sectional view showing an injection mold for carrier molding in a precision substrate storage container according to a second embodiment of the present invention.

FIG. 6 is an exploded perspective view showing a third embodiment of the precision substrate storage container according to the present invention.

FIG. 7 is an explanatory diagram showing a contact angle of a water droplet on a semiconductor wafer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Storage container 2 Container main body 4 Lid 5 Outer box 6 Carrier 11 Back wall 14 Pressing member 18 Support piece 19 Photocatalyst layer 20 Transmission area 24 Pod (container main body) W Semiconductor wafer (precision substrate)

Claims (4)

[Claims] 1. A precision substrate storage container for storing a precision substrate in a storage container, comprising: a photocatalyst layer provided inside the storage container; and a photocatalyst layer provided in the storage container. A precision substrate storage container comprising: a transmission region for guiding ultraviolet light. 2. The container body according to claim 1, wherein the container includes a container body made of a synthetic resin that houses the precision substrate, and a lid body made of a synthetic resin that sealably covers an opening of the container body. The precision substrate storage container according to claim 1, wherein at least one of the lid and the photocatalyst layer is integrally formed. 3. The precision substrate storage container according to claim 2, wherein said container main body and / or said lid are made of polytetrafluoroethylene resin. 4. The precision photocatalyst according to claim 1, wherein the photocatalyst layer comprises a catalyst comprising one or more metal oxides selected from Ti, Zn, Sn, W, Bi, and Fe. Substrate storage container.