JP2002313903A - Clean material storage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a storage which can prevent the contamination of an organic material on the surface of a kept substrate. SOLUTION: The storage includes a storage space 10 for storing clean materials within a clean room 12 in a state of being isolated from the clean room. A storage clean air generating means 36 can generate, e.g. storing clean air controlled so as to have total concentration of 10 ppb or less in hydrocarbons containing methane by a catalytic combustion method and not containing fine particles, and can supply it from air supply systems 32 and 46 into the storage space 10. Therefore, the contamination of the organic material on the surface of substrate can be effectively prevented. At this time, since an inert gas or the like is not used, the storage can be safely performed with a low running cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clean material storage, and more particularly to a semiconductor device and a liquid crystal display (LC).
The present invention relates to a local clean space for storing clean materials such as semiconductor substrates and LCD substrates in a clean space such as a clean room for manufacturing D).

[0002]

2. Description of the Related Art In a semiconductor or LCD panel manufacturing process, many steps are required to obtain a finished product from a bare wafer or elementary glass. For example, 1MD from bare wafer
A semiconductor manufacturing line leading to a RAM chip is composed of about 200 processes. In addition, for example, 9.4
The LCD panel manufacturing line leading to the type TFT includes about 80 processes. It is difficult to always continuously supply a product to each process. For example, in a TFT-LCD production line, a semi-finished product on which a circuit is completely formed in a previous process is transferred to a subsequent process. Substrate for tens of hours,
In some cases, it is stored in a storage (stocker) kept in a clean atmosphere.

When semiconductor substrates and LCD substrates are stored in a normal clean room atmosphere, organic substances derived from the clean room atmosphere may adhere to their surfaces. For example, when an insulating oxide film (SiO ₂ ) is formed at a high temperature of 650 ° C. or more in a state where an organic substance derived from an atmosphere adheres to a silicon wafer as a semiconductor substrate,
The carbon component in the organic substance changes into SiC and is taken into the insulating oxide film (SiO ₂ ). In this case, the withstand voltage of the insulating oxide film is significantly reduced. Also, the leakage current increases significantly. Further, for example, the organic matter derived from the atmosphere is LC
When amorphous silicon (a-Si) for a thin film transistor (TFT) is formed on the glass surface in a state where the glass adheres to the D substrate glass, poor adhesion between the glass and the a-Si film occurs. As described above, the semiconductor substrate and LC
It is known that the organic matter derived from the clean room atmosphere attached to the surface of the D substrate adversely affects the electrical characteristics of the semiconductor element and the LCD.

Accordingly, in order to prevent such product defects, organic substances adhering to the surface must be removed by a cleaning technique. However, known organic cleaning techniques,
For example, when organic substances adhering to the surface are removed by ultraviolet / ozone cleaning, several minutes are required as a cleaning time per one substrate, and frequent cleaning lowers the throughput.

Therefore, measures to prevent organic contamination on the substrate surface due to exposure to the atmosphere in a clean room have been sought, and various storages that can store the semi-finished substrate without causing organic contamination on the surface of the substrate have been proposed. Have been.

[0006] For example, a technique for preventing organic substance contamination in a storage by removing gaseous organic matter as well as particulate matter by combining a high performance filter such as a HEPA filter or an ULPA filter with a chemical filter. Has been proposed. However, conventional high-performance filters (HEPA, ULPA) are located upstream of the chemical filter.
) Cannot remove particulate contaminants generated from the chemical filter itself. On the other hand, if a normal high-performance filter is installed downstream of the chemical filter, There is a problem that gaseous contaminants generated from the constituent materials of this high-performance filter cannot be removed, so that the effect cannot always be achieved.

[0007] For example, Japanese Patent Application Laid-Open No. 6-156622 proposes a technique in which the inside of a storage (or wafer stocker) is filled with an inert gas instead of clean air to prevent organic contamination of a substrate. ing. By storing the substrate in such an inert gas chamber, the surface contamination by organic substances is reduced to about 1/5 to 1/2 compared with the case where the substrate is stored in a clean room filled with clean air. Can be reduced. However, if the storage (or wafer stocker) is filled with inert gas,
Attention must be paid not only to the high cost of inert gas but also to safety issues. That is, if a large amount of inert gas leaks into the clean room due to some accident, there is a risk that nearby workers may suffocate.

Further, for example, Japanese Patent Application Laid-Open No. 5-286567
In Japanese Patent Laid-Open Publication No. H11-264, a technique is proposed in which a semi-finished substrate is housed and stored in a closed container in which an inert gas is sealed. However, such containers are often used for finished IC chips or LCs.
Although it is suitable to store D glass and carry out the whole container as it is, it is not suitable as a method of storing materials that are frequently taken in and out like semi-finished substrates.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the conventional clean material storage, and has been developed for cleaning clean materials such as semiconductor substrates and LCD substrates. , Can be stored without causing organic contamination, and does not use inert gas,
An object of the present invention is to provide a clean material storage that can be operated safely and at a low running cost, and is suitable for storing materials that are frequently taken in and out.

[0010]

In order to solve the above-mentioned problems, the invention according to claim 1 is provided in a surrounding clean space which is maintained at a first cleanliness level and is isolated from the surrounding clean space. In a clean material storage configured as a first local clean space installed in the above, the total concentration of hydrocarbons including methane is controlled to 10 ppb or less and the second containing no fine particles is contained.
Storage clean air generating means for generating clean air for storage maintained at a degree of cleanliness, and air supply means for supplying clean air for storage to a storage space in the first local clean space. With such a configuration, it is possible to effectively prevent organic substance contamination on the substrate surface. At this time, since no inert gas is used, the storage can be operated safely and at low cost.

Further, as described in claim 2, the first local cleaning space includes a storage space and a buffer space interposed between the storage space and the surrounding cleaning space, and is provided by an air supply means. If the storage clean air is configured to flow from the storage space to the buffer space, it is possible to effectively prevent air contaminated from the buffer space, for example, in the surrounding clean space from entering the storage space.

Further, as set forth in claim 3, an evaluation device having a first local cleaning space and a second local cleaning space isolated from the surrounding cleaning space is provided, and the evaluation device is provided through a gas introducing means. The clean air for storage in the first local clean space may be introduced into the second local clean space to evaluate a degree of organic contamination in the first local clean space. This evaluation device monitors whether or not the amount of organic contaminants on the surface of the clean material disposed in the first local clean space is kept below an allowable value, for example. Can be configured. With such an evaluation device, the degree of organic matter contamination in the first local clean space where clean materials are stored can be observed over time, so that organic matter contamination in the first local clean space progresses,
Before the stored material is contaminated with organic matter and the yield of the product is reduced, it is possible to take measures against organic matter contamination. Further, such an evaluation device can solve the problem that the filter replacement time, which has conventionally been a problem when the activated carbon filter is used, is unclear.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of a clean material storage configured according to the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 1 to 3 show a storage 1 configured to be suitable for storing an LCD substrate according to a first embodiment of the present invention.
0 is shown, FIG. 1 is a plan view of the storage 10, FIG. 2 is a side view of the storage 10 viewed from A in FIG.
Shows a side view of the storage 10 as viewed from B in FIG.

As shown, a storage 10 according to the present invention.
Is configured as a first local clean space that is installed in a peripheral clean space (clean room) 12 maintained at a first cleanliness level and separated from the space. The storage 10 includes a front room 16 as a buffer space for transferring an LCD substrate 18 between the clean room 12 and the clean room 12, which is separated by the partition 14, a transfer room 20 for transferring the LCD substrate 18, and an actual LCD substrate 18. And a storage room 22 for storing 18. In the illustrated example, the transfer room 20 and the storage room 22 are configured as a common space (storage space). However, the transfer room 20 and the storage room 22 are separated by an openable partition, and It is also possible to configure so that the resulting contamination does not enter the storage room 22.

In the clean room 12, a carrier table 24 is provided adjacent to the partition wall 14 of the front chamber 16, and a carrier 26 capable of storing a predetermined number of LCD substrates is mounted on the carrier table 24. Is done. Front room 16
A transfer mechanism such as a transfer arm 28 is installed in the inside, and the carrier 26 containing the LCD substrate can be transferred from the carrier table 24 to the carrier table 30 in the front room 16. Further, an air supply system 32 is provided in the front chamber 16, and the storage clean air generation device 3 described later with reference to FIG. 5 is provided.
6, a catalytic combustion device or a storage clean air generator 36 'described later with reference to FIG. 6, that is, a storage clean air generated by the activated carbon filter unit is supplied to the air supply system 3.
2 can be introduced. Further, an exhaust system 34 is provided in the front chamber 16 so that the inside of the front chamber 16 can be exhausted as needed.

Further, the front chamber 16 and the transfer chamber 20 are separated by a partition 38 which can be opened and closed. In the transfer chamber 20, a movable table 39 movable along the storage chamber 22 and the movable table 39
And the transfer arm 40 installed in the first position. For example, when storing materials, the partition 38 is opened, the carrier 26 installed on the carrier table 30 in the front room 16 is taken out by the transfer arm 40, and the movable table 39 is moved to the empty stocker position in the storage room 22. The carrier 26 can be transferred and stored in the empty stocker.

In the storage room 22, a plurality of stockers 42 are formed. In the example shown in the figure, two stocker units 44 in two upper and lower stages and three horizontal rows are provided in parallel, but the present invention is not limited to this embodiment, and the storage room 22 in which an arbitrary number of stockers are arbitrarily arranged is provided. Needless to say, it can be applied to Further, in the illustrated example, the stocker 4 that accommodates the carrier 26 that accommodates a predetermined number of LCD substrates 18.
Although FIG. 2 is shown, the storage room can be configured by a stocker that can directly accommodate the LCD substrate 18.

Further, in addition to the above-mentioned configuration, it is also possible to provide an air supply system 46 and a high-performance filter 48 in the storage room 22, as in a storage 10 'shown in FIG. According to this configuration, for example, the total concentration of hydrocarbons is 10 pp by the storage clean air generator 36 described later with reference to FIG.
b and the high-performance filter 4
After being adjusted to the second degree of cleanliness in step 8, it can be introduced into the storage room 22 as clean air for storage. In this specification, the cleanliness of the clean room forming the surrounding clean space is referred to as a first cleanliness, and the cleanliness of the first local clean space for storing materials is referred to as a second cleanliness. However, these cleanliness includes
It can be set arbitrarily as needed. Further, in the illustrated example, the configuration in which the second cleanliness is achieved by the filter 48 in the storage room 22 is shown, but the second cleanliness is achieved in the clean air generator 36 for storage by an appropriate filter means. It can also be configured as follows. The storage room 22 is provided with an exhaust system 50 so that the inside of the storage room 22 can be evacuated as needed.

Next, with reference to FIG. 5, a description will be given of a storage clean air generator 36 for generating storage clean air applied to the storage 10 'shown in FIG. As shown, the storage clean air generator 36 includes a compressor 52 for compressing the intake air, a reaction tower 54 for heating the air to react with the catalyst, and a heat exchanger 56 for cooling the processed air. It is mainly composed of Further, the storage clean air generator 36 includes a gas filter 58, a pressure gauge 60, and a flow meter 62 in an air supply path between the compressor 52 and the reaction tower 54.
Is provided, and the cleanliness, pressure, and flow rate of the generated clean storage air can be adjusted.
Further, an oxidation catalyst such as platinum or palladium is placed in the reaction tower 54, and the hydrocarbons contained in the air can be burned and decomposed by the heater 64 as shown in the following formula. it can. In the figure, 66 is the reaction tower 54
This is a temperature-indicating control alarm for preventing overheating. 2C _n H _m + (m / 2 + 2n) O ₂ → 2nCO ₂ +
mH ₂ O

In this way, the clean air or the outside air in the clean room is supplied to the compressor 52 at, for example, 420 ° C.
The reaction gas is sent to the reaction tower 54 heated in the reaction tower 54, reacts with the oxidation catalyst in the reaction tower 54, and hydrocarbons are decomposed into water and carbon dioxide gas and removed. By the way, in a normal clean room air, moisture is 10,000 ppm to 20,000 p.
pm, several hundred ppm of carbon dioxide, and several ppm of total hydrocarbons including methane, so even if all the hydrocarbons are burned, the amount of water and the amount of carbon dioxide are the same as those originally contained. Only a slight increase in comparison. The clean air obtained by burning and decomposing the hydrocarbons is cooled to room temperature by the finned heat exchanger 56, and is taken out from the clean air outlet 68 to the outside.

Next, with reference to FIG. 6, a description will be given of a storage clean air generator 36 'for generating storage clean air applied to the storage 10 shown in FIGS. As shown, the storage clean air generator 36 'includes a blower 652 for taking air into the unit or circulating air in the system, and a particle coarse filter for suppressing clogging of the activated carbon filter. 654 and an activated carbon filter 65 for adsorbing hydrocarbons in the air
6 and a particle removal filtration filter 6 for removing activated carbon fine particles which may be generated from the activated carbon filter on the downstream side.
58 mainly. The frequency of the blower 652 is controlled by the inverter 660, so that the processing air volume can be arbitrarily adjusted.

The activated carbon filter 656 can be in the form of pellets, fibers, or honeycombs depending on the shape of the activated carbon used as the base. In the present embodiment, a pellet-shaped spherical activated carbon material that does not use any impregnation so as not to generate gaseous impurities is used as the activated carbon as a filter material. In general, a fibrous and honeycomb activated carbon filter uses another organic fiber or an adhesive to adjust its shape or maintain its strength, so that an organic gas is generated from the organic fiber or the adhesive.
In addition, when the activated carbon material in the form of a pellet is attached to urethane or the like with an adhesive, an organic gas is generated from the urethane or the adhesive. Since such an organic gas becomes a secondary pollution source, some countermeasures are required. Therefore, the present embodiment employs a configuration in which spherical activated carbon is filled in a container made of a material that does not generate gaseous impurities.
In this specification, as a material that does not generate gaseous impurities, for example, a metal such as stainless steel or aluminum having corrosion resistance and low surface roughness that has been subjected to degreasing treatment, or a ceramic such as alumina or zirconia can be used. . However, in the case of stainless steel, it is preferable to use one subjected to electrolytic polishing. In the case of aluminum, it is preferable to use aluminum that has been subjected to a surface treatment such as a boehmite treatment.

FIGS. 7 and 8 show an example of a filter made of a material that does not generate gaseous impurities. The filtration filter 420 is made of a metal frame 412a,
12b and only a glass fiber material filter 414. As shown in FIG. 8, in the present embodiment, no binder is contained (or even if a binder is contained, volatile organic substances are removed by baking-out processing or the like).
Filter paper type flat filter medium 414 consisting of glass fiber only
Is bent to form a filter element. And
The upper and lower end portions 414a of the filter having the uneven shape are metal mold frames 4 formed into an uneven shape corresponding to the uneven shape of the filter.
It is sandwiched between the concave and convex portions 12a and 412b (the upper and lower surfaces of the metal mold frames 412a and 412b shown in FIGS. 8A and 8B). Also, the right and left end portions 414b of the filter having an uneven shape.
Is between the flat surfaces of the metal molds 412a and 142b (FIG. 8).
(A) and (b)). With this configuration, the sealing material that generates gaseous impurities and the like can be used without using the sealing material shown in FIG.
A filter 420 as shown in FIG. FIG. 8A shows a state where the particle removal filter is assembled, and FIG. 8B shows one of the metal frames 412a.
FIG. 4 is a perspective view showing a state in which is removed. The particle removal filter 420 assembled in this manner is a metal mold 4
The filter medium 414 together with 12a and 412b is baked at, for example, 300 ° C. to remove all organic substances. The filtration filter 420 is attached between the air passages 662 (FIG. 6) via a fluorine resin packing that does not generate organic gas at normal temperature.

The filtering filter can be configured as shown in FIG. Filtration filter 4 shown in FIG.
20 ′ is a particle removal filter 42 shown in FIGS.
Unlike the case of No. 0, the filter element 414 'made of only a glass fiber that does not contain a binder (or that contains a binder and volatile organic substances have been removed by baking out, etc.) is bent in a zigzag manner to form a filter element. The zigzag-shaped filter 414 'is sandwiched between metal molds 412a' and 412b 'formed in a zigzag shape corresponding to the zigzag shape. Except for such a difference in shape, the particle removal filter 420 'shown in FIG. 9 has substantially the same configuration as the particle removal filter 420 shown in FIGS. 7 and 8, and therefore, detailed description is omitted. I do.

FIG. 10 shows an air path 662 (FIG. 6).
Activated carbon filter 656 and particle removal filter 658
Yet another embodiment is shown for attaching. As shown, the activated carbon filter 450 according to the present embodiment is shown.
A filter unit composed of a spherical activated carbon layer 456 in which spherical activated carbon is disposed in a single layer between stainless steel meshes 452 and 454 and an air passage space 458 downstream of the spherical activated carbon layer 456 is laminated in a plurality of stages. On the downstream side, a filter 460 for removing secondary particles generated from the spherical activated carbon layer 456 is provided. Thus, by laminating the single-layer spherical activated carbon layer 456 through the air passage space 458 in a plurality of stages, it is possible to obtain a filter structure having a small pressure loss. In addition,
By using a material that does not generate gaseous impurities for all filter components, it is possible to prevent the filtration filter itself from becoming a contamination source of organic matter contamination.

Returning to FIG. 6 again, the clean air from which the organic gas has been removed by the activated carbon filter 656 as described above is taken out from the clean air outlet 664. In addition, it is necessary to adopt a material that does not generate impurity gas for all the constituent members of the air passage and the storage downstream of the clean air outlet 664. In addition, in order to prevent organic substances from being contaminated by gaseous impurities, a non-degassing fluororesin packing was used for all the joints of the air passages and the constituent members of the storage that require sealing. As shown in the drawing, in the clean air generator for storage 36 ', the differential pressure before and after the filtration filter 658 for particle removal is monitored by the differential pressure gauge 666, and it is possible to know the replacement time of the filtration filter 658 for particle removal.

The clean air purifying apparatus for storage shown in FIGS. 6 to 10 adopts a configuration in which hydrocarbons in the air are adsorbed by an activated carbon filter. However, the present invention is not limited to such an example, and is shown in FIG. Gaseous impurity treatment system 500 having a fluidized bed adsorption tower 550 using activated carbon filter media
It is also possible to use This gaseous impurity treatment system 500 uses a fluidized bed adsorption tower 550, and a medium-performance filter 522 that does not generate gaseous impurities on the downstream side.
And a high-performance filter 524 are sequentially arranged in series from the upstream side. When attaching the medium-performance filter 522 or the high-performance filter 524 to the system, it is preferable to use a seal member that does not generate an organic substance gas, for example, a fluorine resin packing such as an inorganic packing or Teflon (registered trademark).

The fluidized bed adsorption tower 550 is roughly divided into a fluidized bed adsorption section 552, a seal section 554, and an adsorption filter medium transport section 556. The fluidized bed adsorber 552 includes an adsorber 558.
A multi-layered perforated plate 560 is provided therein. The adsorption filter medium (for example, granular activated carbon) is supplied to the fluidized bed adsorption section 55.
2, the fluidized bed 56 having a stationary bed height of 10 to 20 mm and a fluidized bed height of 20 to 40 mm on the multistage perforated plate 560, for example.
2 and flow down in each stage while moving and moving in each stage.
From 60a, it sequentially falls down. During this time, the adsorbed filter medium is supplied from the air intake port 563 through the damper 563b and the spiral blower 563a, and the processing air 5 flowing upward is taken up.
64 and uniformly adsorbs impurity gas components in the processing air. On the other hand, the purified air 566 is discharged from the upper portion 558a of the adsorption tower 558. In addition, the adsorption filter medium that has reached the adsorption tower bottom 558b forming the sealing section 554 is returned to the uppermost stage of the adsorption tower by the adsorption filter medium transport section 556, and moves to the adsorption step again.

Gas utilizing the fluidized bed adsorption tower 550
The device for removing impurities in the form of a filter
Extremely low ventilation resistance because the air to be processed passes through the inside
There is an advantage that. For example, 0.7mm diameter granular activated carbon
Of a fluidized bed with a height of 1.5 cm consisting of 1 m / s
Only 10 mmH of air flow resistance when air passes through ₂
O. In addition, ppm order contained in the air to be treated
To reduce the concentration of gaseous organic impurities to less than 1 ppb
No more than 7 fluidized beds, ie 70 mmH₂O ventilation
It is enough to allow for resistance. In addition, long-term continuous operation
In the meantime, the adsorption filter medium in the adsorption tower adsorbs impurities and breaks
To a state where the adsorption performance is lost). Therefore, break through
It is necessary to change the adsorbent medium as soon as possible for safety.
You. For example, if the lifespan before breakthrough is 2 years, half a year
Can be replaced when needed.

A description will now be given of the adsorbing filter medium conveying section 556 shown in FIG. The adsorption filter medium transport unit 556 includes the turbo blower 5
68, and the compressed air 578 is sent to the uppermost stage of the adsorption tower by the turbo blower 568 via the damper 574, the three-way pipe 572, and the airflow transport pipe 576. Three way tube 5
At 72, the compressed air 578 and adsorbent media exiting the outlet 570 are mixed. The first path 570 a and the second path 570 a
There are two systems of a path 570b, and the adsorption filter medium taken out of the first path 570a is transported by compressed air 578 to the uppermost stage of the adsorption tower. At this time, the second route 570b
Is closed by closing the damper 574a and the valve 580.

On the other hand, when replacing the adsorption filter medium, the spiral blower 563a is stopped, the damper 574 is closed, and the first path 570a is closed. Conversely, the second path 570b opens,
In the three-way pipe 572a, the compressed air 578a that has passed through the damper 574a is mixed with the adsorption filter medium that has come out of the outlet 570. This adsorption filter medium is transported by air to a used filter medium storage tank 582 via a valve 580. The compressed air 578a used for the airflow is discharged to the outside through an exhaust port 582a attached to the storage tank 582.

The used filter medium of the adsorption tower 558 is all stored in the storage tank 5.
82, the valve 5 attached to the lower part of the storage tank
Open 84 to take out the used filter medium to the outside. On the other hand, the unused adsorption filter medium is supplied to the unused filter medium storage tank 5 through the supply port 584a.
Put in 84. After that, the unused adsorptive filter medium is supplied to valve 58
6 through the inlet 588 and into the adsorption tower 558.

In the fluidized bed adsorption tower 550, the adsorbing filter medium itself in a fluidized state is a source of fine particles. However, according to the present embodiment, the fluidized bed adsorption tower 55
0, a medium-performance filter 522 and a high-performance filter 524 that do not generate gaseous impurities are installed.
It is possible to supply clean air containing neither gaseous impurities nor particulate impurities. The details of the medium performance filter 522 and the high performance filter 524 will be described later. In the illustrated example, the medium-performance filter 522 and the high-performance filter 524 are arranged in series, but a configuration in which only the high-performance filter 524 is provided may be adopted. However, in such a fluidized bed adsorption tower 550, the adsorbing filter media in a fluidized state generate numerous micron-sized fine particles by rubbing each other.
And a high-performance filter called ULPA, for example, a dust concentration of 1 mg / m ³ and a ventilation air velocity of 0.3
In the case of m / sec, clogging occurs completely in about two months.

Accordingly, as shown in this embodiment, first, the medium-performance filter 522 removes the micron-size filter medium wear particles, and the sub-micron-size fine particles that cannot be removed by the medium-performance filter 522 are further downstream. It is preferable to adopt a configuration in which the filter is removed by the high-performance filter 524 provided in the above. Further, the medium-performance filter 522 may be provided with a regeneration device used for conventional bag filter regeneration to extend the replacement life of the filter. When attaching the medium-performance filter 522 or the high-performance filter 524 to the system, a sealing member that does not generate an organic gas,
For example, it is preferable to use an inorganic material packing or a fluororesin packing such as Teflon.

Next, the operation of the storage constructed as described above will be described with reference to FIGS. First, the operation of loading clean materials will be described. The carrier 26 containing the LCD substrate 18 to be stored is placed on the carrier table 24 in the clean room 12. Next, the partition wall 14 separating the clean room 12 and the front room 16 is opened, and the carrier 26 is held by the transfer arm 28 and accommodated in the front room 16, and is placed on the carrier table 30 in the front room 16.
Thereafter, the partition 14 is closed, and the front room 16 and the clean room 1 are closed.
2 and a storage clean air generator 36, 3
From 6 ', through the air supply system 32, the contact angle or the surface resistivity of pure air with no fine particles containing pure methane containing hydrocarbons controlled to a total concentration of 10 ppb or less, or pure water dropping on the surface of a clean material is reduced. Clean air that does not contain fine particles and is controlled so that it can be maintained in a state substantially equivalent to that immediately after cleaning is sent into the front chamber 16. At this time, the front chamber 16 forms an isolated space isolated from the adjacent chamber (therefore, the partition 38 between the front chamber 16 and the transfer chamber 20 is closed), and the same amount of air as the air supply amount is provided. Is exhausted from the exhaust system 34. Front room 16
After the internal atmosphere has been sufficiently replaced with clean air for storage,
The partition 38 between the front chamber 16 and the transfer chamber 20 opens, and the transfer arm 40 of the transfer mechanism inside the transfer chamber 20 causes
The carrier 26 is taken into the transfer chamber 20 from the front chamber 16. Next, the moving table 39 moves to the position of the empty stocker 42 in the storage room 22, and stores the held carrier 26 in the empty stocker 42. The storage clean air is fed into the stocker 42 from the air supply system 46, and an airflow that passes through the carrier 26 and the transfer chamber 20 and wraps around the lower portion 51 of the stocker 42 is formed as indicated by an arrow in FIG. . At this time, the storage room 22 and the transfer room 20 form an isolated space isolated from the adjacent room (accordingly, the partition 38 between the transfer room 20 and the front room 16 is closed), and the air supply amount is reduced. The same amount of air is exhausted from the exhaust system 50.

Next, the operation of unloading the carrier 26 stored for a certain period in the stocker 42 will be described.
First, the moving table 39 moves to the position of the stocker 42 in which the carrier 26 to be carried out is stored, and the carrier 26 is held by the transfer arm 40. The moving table 39 moves to the position of the front room 16. At this point, the front chamber 16 is closed, and the inside thereof is kept in a storage clean air atmosphere. Next, the partition wall 38 is opened, and the transfer arm 40 is moved to the carrier 26.
Is placed on the carrier table 30 in the front room 16. afterwards,
After closing the partition 38 between the transfer room 20 and the front room 16, the partition 14 between the front room 16 and the clean room 12 is opened, and the carrier 26 on the carrier table 30 is moved by the transfer arm 28.
Thereby, it is placed on the carrier table 24 in the clean room 12, and the unloading operation is completed.

In the embodiment shown in FIGS. 1 to 4, the clean air for storage is supplied to the front chamber 16 via the air supply system 32. As shown in FIG. The system 32 is omitted, and an opening 37 is provided that penetrates a partition 38 that separates the front chamber 16 from the transfer chamber 20 (storage space), and a part of the clean air for storage sent to the storage chamber 22 is transferred to the transfer chamber. It is also possible to adopt a configuration in which the fluid flows into the front chamber 16 through the space 20. According to such a configuration, the airflow of the storage clean air always flows from the storage room 22 to the front room 16 via the transfer room 20.
It is possible to effectively prevent contamination generated in the front room 16 and the transfer room 20 from entering the storage room 22.
At this time, in order to completely remove even particles that may be generated on the way from the air supply system 46 to the storage chamber 22, a particle removing filter 48 made of a material without degassing is provided. Can also.

FIG. 13 shows still another embodiment of the clean material storage according to the present invention. This storage is an evaluation device 100 (for evaluating the degree of organic substance contamination in the storage room 22 (or the transfer room 20, the front room 16) in addition to the storage described with reference to FIGS. 200) is installed. In this specification, the same reference numerals are given to components having the same functional configuration in each drawing, and redundant description is omitted.

This evaluation device 100 (200)
As shown in the figure, the surrounding clean space (clean room) 12
14 and FIG. 1 which are isolated from a storage space (first local clean space) including the front room 16, the transfer room 20, and the storage room 22.
And a chamber 102 (202) constituting a second local cleaning space as shown in FIG.
In (202), it is possible to supply the clean air atmosphere for storage in the storage room 22 through the conduit 70. The evaluation result by the evaluation device 100 (200) is sent to the controller 72, and the controller 72 issues, for example, an air supply interruption command to the storage-use clean air generator 36 (36 ') according to the result. Can be. Alternatively, when a backup device configuration described later with reference to FIGS. 20 and 21 is employed, the controller 72 can issue a predetermined command to the backup device. Note that FIG.
In the embodiment shown in FIG. 20, the pipe 70 for introducing the atmosphere to be evaluated into the evaluation device 100 (200) is configured as a pipe branched from the exhaust system 50 of the storage room 22, but as shown in FIGS. In addition, the storage clean air generator 36
It is also possible to adopt a configuration in which the pipeline 71 is provided so as to branch off from the air supply system 46 of (36 ').

The evaluation device 100 (200) may be any device that can evaluate the degree of organic contamination in the storage spaces (front room, transfer room, storage room) 16, 20, and 22. X-ray photoelectron spectroscopy (XPS: X-ray Photoelectron)
Spectroscopy) can be used. This X-ray photomolecular spectroscopy (hereinafter referred to as XP
It is called S method. ) Is to qualitatively / quantitatively analyze the elements present on the sample surface by irradiating the measurement sample with soft X-rays in a high vacuum and measuring the energy and number of photoelectrons that escape from the sample surface with a spectrometer. It is. In the evaluation of the trace amount of surface organic matter contamination by the XPS method, the amount of organic matter contamination is determined by the ratio of the number of carbon atoms to the total number of atoms in the analysis region at a depth of several tens of angstroms from the surface, or the known amount existing in the analysis region. Is represented by the ratio of the number of carbon atoms to the number of atoms of the element. A substrate whose surface is insulated is put into a chamber in the apparatus of the XPS method and exposed to the atmosphere of the storage space. The chamber is evacuated at regular intervals to evaluate the amount of organic contaminants on the substrate surface. The degree of contamination of the atmosphere in the storage space can be determined from the change over time in the amount of contamination.
Further, by using such an evaluation device, it is possible to solve the problem that the replacement time of the filter, which has conventionally been a problem when the activated carbon filter is used, is unclear, and to know deterioration of the activated carbon filter.

The evaluation apparatus based on the XPS method as described above
It can measure the amount of organic contaminants with high accuracy, so it is an effective means to evaluate the atmosphere that causes organic contaminants on the glass substrate surface in the storage room.However, since high vacuum equipment and spectrometers are indispensable, it is very effective. Expensive.
Further, the XPS method is an analysis method that is not suitable for so-called in-line analysis, in which measurement is performed in a state where a sample collection place and an analysis place match. Therefore, an evaluation apparatus 100 using a change in the surface resistivity of the substrate surface having an insulating surface as shown in FIGS. 14 to 16 or an insulating or conductive surface as shown in FIGS. By using the evaluation device 200 utilizing the change in the contact angle of the droplet dropped on the substrate surface, accurate in-line analysis can be performed with a cheaper configuration.

First, an evaluation apparatus 100 utilizing a change in the surface resistivity of a substrate having an insulating surface will be described with reference to FIGS.

As shown in FIG. 14, the evaluation device 100
An isolation space 102 is provided which is isolated from the first local space and the surrounding clean space. The isolation space 102 can be configured as a chamber isolated from the surroundings by, for example, an aluminum partition. Inside the isolated space 102, a glass substrate 104 having a clean surface 104a from which organic substances have been removed is provided. In this embodiment, since the glass substrate 18 is stored in the storage room 22, the glass substrate 104 is used as an evaluation target of organic contamination.
When a silicon wafer is stored in the storage room 22, it is preferable to use the silicon wafer as an evaluation target of organic contamination. As described above, by using a substrate having the same material surface as the material of the material stored in the storage as an evaluation target, it is possible to perform more accurate evaluation of organic contamination. Further, it is preferable that the leaving time after the cleaning of the substrate to be measured or observed in the evaluation device is the same as the leaving time after the cleaning of the clean material stored in the storage. In this embodiment, since the surface of the substrate needs to be insulative, when a silicon substrate is used, an insulating film needs to be formed on the surface of the silicon substrate.

On the glass substrate 104, a metal electrode 106 for measuring surface resistivity is deposited. FIG. 15 (A)
(B) shows a metal electrode 10 deposited on a glass substrate 104;
6 is shown schematically. As shown in the figure, the metal electrode 106 has a first electrode 106a deposited in a substantially circular shape having a diameter D1 substantially at the center of the surface 104a of the glass substrate 104, and the first electrode 106a.
06a and a substantially annular second diameter D2 concentrically arranged.
It is composed of an electrode 106b and a ground electrode 106c deposited in a substantially circular shape on the back surface 104b of the glass substrate 104.
These electrodes 106 correspond to the surface 104 of the glass substrate 104.
It is possible to constitute by directly depositing a conductive material on a and b. Alternatively, these electrodes 106 are formed on the surfaces 104a and 104b of the glass substrate 104, for example, by plasma CVD.
To form an insulating film, and furthermore, a conductive material is deposited on the surface of the insulating film by, for example, a sputtering apparatus. Further, the first and second electrodes 106a, 106a,
Between 06b, a power supply 108 and an ammeter 110 are connected in series, and a surface resistivity meter 112 (portion surrounded by a dotted line in the figure) is configured. In the illustrated example, the surface resistivity meter 112 is shown to be configured to include the substrate 104 and a part of the isolated space 102, but this is for the sake of easy understanding. Said surface resistivity meter 112 has at least two
Any device that can measure the electrical resistance between points can be used, and various devices can be used. Although a glass substrate is used as the sample substrate 104 in this embodiment, another substrate, for example, a silicon wafer on which an insulating film is formed is used as the sample substrate according to the measurement target, and the surface of the sample substrate is used. It is also possible to measure the surface resistivity by using the surface resistivity meter 112 with the electrode 106 installed at the bottom.

Further, into the isolated space 102, pressurized purified air humidified by the humidity generator 114 can be introduced through the air supply valve V1, and oxygen is supplied from the oxygen cylinder 116 through the air supply valve V2. Can be introduced, and the atmosphere to be evaluated can be introduced via the air supply valve V3.
An exhaust valve V4 communicating with the humidity sensor 118, an exhaust valve V5 communicating with the exhaust pump 120, and an exhaust valve V6 communicating with the air pump 122 are connected to the isolated space 102, respectively. The relative humidity detected by the humidity sensor 118 is sent to the controller 124,
Numeral 24 performs feedback control of the humidity generator 114 according to the detected value. An ultraviolet lamp 126 is provided above the isolated space 102 so that the surface 104 a of the glass substrate 104 can be irradiated with ultraviolet light.

First, in order to measure the surface resistivity of the glass substrate immediately after cleaning, the valves V1 and V4 are opened while the valves V2, V5, V3 and V6 are closed, and the pressure is controlled to a predetermined relative humidity. The pressure controlled gas is sent into the isolation space 102. The pressurized humidified gas is supplied from the pressurized purified air to the humidity generator 114.
, A so-called split flow method. In order to maintain the inside of the isolated space 102 at a predetermined constant relative humidity,
The partial flow rate of the humidity generator 114 is feedback-controlled by the humidity sensor 118 and the controller 124 installed on the outlet side of the humidity control gas. After the inside of the isolated space 102 reaches a predetermined relative humidity, a voltage is applied to the electrode 106 for measuring the surface resistivity, and the initial surface resistivity (Rs _i ) of the clean glass substrate is measured by the surface resistivity meter 112. I do.

Next, the valves V1 and V4 are closed and the valve V
3. Open V6, operate the air pump 122, suck the gas in the atmosphere to be evaluated into the isolated space 102, and expose the surface 104a of the glass substrate 104 with the gas in the atmosphere to be evaluated for a predetermined time. At the end of exposure, valves V3 and V6
Is closed, the valves V1 and V4 are opened, and the controller 124 again controls the inside of the isolated space 102 to a predetermined relative humidity (relative humidity substantially the same as the relative humidity when the surface resistivity of the cleaned substrate is measured). ) to atmosphere, the surface resistivity meter 112, measuring the surface resistivity (Rs _f). Thus, by repeating the measurement of the surface resistivity (Rs _f) at regular intervals, you can track the time course of organic contaminants of the clean surface.

A UV (ultraviolet) lamp 126 is provided in the isolated space 102, and after a series of time-dependent changes in surface resistivity are measured, the valves V1, V4, V
3, V6 is closed, valves V2 and V5 are opened, and pressurized oxygen gas is sent from the oxygen cylinder 116 into the isolated space 102, and UV light is applied to the surface 104a of the glass substrate 104.
The so-called ultraviolet / ozone cleaning is performed by irradiating light to decompose and remove organic substances attached to the surface 104a. After the ultraviolet / ozone cleaning, the valve V2 is closed, the valve V1 is opened while the valve V5 is opened, and the ozone gas generated in the isolated space 102 during the cleaning is discharged to the outside by the exhaust pump 120 while the isolated space 102 is opened. Replace the inside with purified air. In this way, preparations are made for the next measurement of the change with time in the surface resistivity of the clean glass substrate.

[0050] Also, organic substances adhering amount of the glass substrate surface was measured by XPS method (carbon / silicon ratio) and increasing rate of the surface resistivity measured in constant relative humidity atmosphere (Rs _{f /} Rs _i)
It has been found that there is a relationship as shown in FIG. As shown in the figure, the surface resistivity also increases in response to the increase in the amount of organic substances attached, and by using this relationship, the measured value of the increase in the surface resistivity is converted to the amount of organic substances attached to the glass substrate surface. be able to. For example, the degree to which various different atmospheres contribute as surface organic contamination sources can be compared based on the rate of increase in surface resistivity when various evaluation target atmospheres are exposed to a glass substrate for a certain period of time. Alternatively, by repeating the surface resistivity measurement of the same glass substrate placed in a specific atmosphere in which the glass substrate is stored at regular time intervals, the amount of organic contamination on the surface of the glass substrate derived from the atmosphere is set to an allowable value. It is possible to constantly monitor whether the following is maintained.

Next, an evaluation apparatus 200 utilizing a change in the contact angle of a droplet dropped on the substrate surface will be described with reference to FIGS.

As shown in FIG. 17, the evaluation device 200
An isolation space 202 is provided which is isolated from the first local space and the surrounding clean space. The isolation space 202 can be configured as a chamber which is isolated from the periphery by a partition made of aluminum, for example. A stage 204 is provided inside the isolated space 202. As shown in FIG. 18, a glass substrate 206 having a clean surface 206a from which organic substances have been removed is mounted on the stage 204. On the glass substrate 206, a glass surface 206a
Syringe 208 for dropping ultrapure water droplet 207
Is provided. As shown in FIG. 18, the glass substrate 206 of the droplet 207 dropped from the syringe 208 is used.
The stage 204 is arranged so that the drop position on the top can be freely changed.
Is provided with a moving mechanism (not shown) that can rotate and move the substrate 206 in a horizontal plane in parallel. In addition,
In this embodiment, since the glass substrate 18 is stored in the storage room 22, the glass substrate 20 is evaluated as an organic contamination evaluation target.
Although 6 was used, when a silicon wafer is stored in the storage room 22, it is preferable to use a silicon wafer as an evaluation target of organic contamination. As described above, by using a substrate having the same material surface as the material of the material stored in the storage as an evaluation target, it is possible to perform more accurate evaluation of organic contamination. In this embodiment, unlike the embodiment of FIG. 14, the substrate surface does not need to be insulative, so that a silicon substrate can be used as it is.

Further, measurement windows 210a and 210b are provided on the side wall of the isolated space 202. Measurement window 21
A light source 212 for illuminating the droplet 207 dropped on the substrate 206 is provided outside the substrate 0a, and a microscope or a magnifying glass for magnifying and observing the image of the droplet 207 outside the measurement window 210b. An image enlarging means 214 is provided. Therefore, the droplet 207 dropped on the glass substrate 206 as shown in FIG. 18 can be exposed to illumination light from the light source 212, and the contact angle α can be measured by the magnifying mirror 214. The method of evaluating the degree of organic substance contamination based on the change in the contact angle of the droplet uses the following principle. The surface of a silicon wafer or glass substrate with an oxide film free of organic contamination is easily water-compatible, that is, hydrophilic, and has a small contact angle. However, when the substrate is contaminated with an organic substance, the surface of the substrate changes to a property of repelling water, that is, becomes hydrophobic, and the contact angle increases. Therefore, the degree of organic contamination can be evaluated by observing the change in the contact angle over time with the apparatus shown in FIG.

In the isolated space 202, an air supply valve V1 is provided.
It is possible to introduce a cleaning gas containing at least oxygen from the cylinder 214 via the gas supply line 1 and to introduce an evaluation gas via the air supply valve V12. Further, the isolated space 202 is provided with an exhaust valve V1 communicating with the introduction / exhaust pump 216 so as to exhaust the cleaning gas.
3 is connected, and an exhaust valve V14 communicating with the air pump 218 is connected so as to exhaust the evaluation gas. An ultraviolet lamp 220 for irradiating the surface 206a of the substrate 206 with ultraviolet light at the time of cleaning the substrate is provided above the isolated space 202.

Next, a method for evaluating organic contamination on the substrate surface using the above-described evaluation apparatus will be described. First, the contact angle of the clean substrate immediately after the cleaning is measured by the magnifying glass 214. After that, the valves V11 and V13 are closed, and both the valves V12 and V14 are opened, and the gas of the atmosphere to be evaluated is sent into the isolated space 202 by the air pump 218. The surface 206a of the substrate 206 for a predetermined time
After exposing to the evaluation atmosphere, the stage 204 is driven,
The substrate 206 in the isolation space 202 is moved in a horizontal plane.
In this embodiment, the stage 204 is configured to be driven. However, the syringe 208 is configured to be freely movable in a horizontal plane, and the syringe 208 is moved while the substrate 206 (stage 204) is stationary. May be. In other words, each time one contact angle measurement is completed, the stage 204 or the syringe 208 is rotated or moved in the horizontal direction,
The droplet is dropped at a position where the droplet has not been dropped yet, and the contact angle is measured again. By repeating the measurement of the contact angle at regular intervals in this manner, it is possible to track the change over time in the amount of organic contaminants on the clean surface.

After a series of measurement of the change of the contact angle with time is completed, both the valve V12 and the valve V14 are closed, and both the valve V11 and the valve V13 are opened.
A cleaning gas containing at least oxygen is supplied into the isolated space 202 from the surface of the glass substrate 206.
so-called ultraviolet rays that decompose and remove organic substances attached to
Perform ozone cleaning. After UV / ozone cleaning, valve V1
1 is closed, valve V13 remains open, and valve V12 is closed.
Is opened, and the inside of the isolated space 202 is replaced with a gas of an atmosphere to be evaluated while the ozone gas generated in the isolated space 202 at the time of cleaning is exhausted to the outside by the exhaust pump 216. In this way, preparation is made for the measurement of the change with time of the contact angle of the next clean glass substrate.

FIG. 19 shows the relationship between the amount of organic matter attached (carbon / silicon ratio) and the contact angle. As shown in the figure, the contact angle increases in accordance with the increase in the amount of the organic substance (carbon / silicon ratio). By utilizing this relationship, the measured value of the contact angle is converted into the amount of the organic substance on the surface of the glass substrate. it can. For example,
The degree to which the various atmospheres contribute as a surface organic contamination source can be compared based on the increase rate of the contact angle when the glass substrate is exposed to various evaluation target atmospheres for a certain period of time. Alternatively, by repeating the contact angle measurement of the same glass substrate placed in a specific atmosphere in which the glass substrate is stored at regular time intervals, the amount of surface organic contamination of the glass substrate from the atmosphere is reduced to an allowable value or less. It is possible to constantly monitor whether or not it is kept.

Now, the storage 10 (1) shown in FIGS.
0 ′), if the storage clean air generator 36 by the catalytic combustion method is operating normally, or if the activated carbon adsorption performance of the storage clean air generator 36 ′ is within the range that can withstand use, FIG. The increase in the surface resistivity of the substrate measured by the evaluation device 100 shown in FIG. 14 is suppressed to several percent per day, or the contact angle of the droplet dropped on the surface of the substrate measured by the evaluation device 200 shown in FIG. Is limited to a few degrees per day. However, the evaluation device 10
When the increase in the surface resistivity measured over time according to 0 or 200 or the increase in the contact angle exceeds the above range (for example, the change in the increase rate of the surface resistivity per day is several tens%) Or the contact angle per day increases to several tens of degrees), some abnormality occurs in the storage clean air generator 36, or the activated carbon in the storage clean air generator 36 'breaks through. , The organic gas in the processing air cannot be sufficiently removed, and it can be determined that organic matter contamination has occurred in the storage space. In such cases,
It is necessary to immediately remove the clean material in storage, wash it again, and store it again. Then, the controller 72 in FIG. 13 sends a predetermined command such as a stop of air supply to the storage clean air generator 36 (36 ′), and repairs the storage clean air generator 36 (36 ′). Or replace the activated carbon filter. Alternatively, FIG.
If a backup mechanism as shown at 0 or 21 is provided, the controller 72 can switch the active storage clean air generator to the backup mechanism.

As the backup mechanism, for example, FIG.
The mechanism 302 shown in FIG. In the backup mechanism 302, the clean air generating apparatus for storage 36 has two first and second systems that can be independently controlled.
It is composed of storage clean air generators 36a and 36b. Then, a part of the clean air for storage sent to the storage 10 through the pipe 71 branched from the air supply system 46 to the storage 10 is sent to the evaluation device 100 (200), where the degree of the organic matter contamination is reduced. Observed over time. For example, when the storage clean air is supplied from the first storage clean air generator 36a (that is, the valve 78 is open and the valve 80 is closed), the organic contamination in the evaluation device 100 (200) is reduced. If so, controller 72 may switch the supply of storage clean air to second storage clean air generator 36b by closing valve 78 and opening valve 80. it can. Then, the first storage clean air generator 36 in which the abnormality has occurred
The activated carbon filter of a can be replaced.

FIG. 21 shows another embodiment of the backup mechanism. In this backup mechanism 304, an inert gas supply source 82 is connected to the air supply system 46 instead of the second storage clean air generator shown in FIG. Therefore, when the evaluation device 100 (200) evaluates that an abnormality has occurred, the controller 72 closes the valve 84 communicating with the storage-use clean air generating device 36 and communicates with the inert gas supply source 82. An inert gas can be supplied to the storage 10 as a temporary measure until the valve 86 is opened and the repair of the storage clean air generator 36 is completed.

Although the present invention has been described with reference to the embodiment in which the present invention is applied to a storage for an LCD substrate, the present invention is not limited to such an embodiment, and those skilled in the art will refer to the claims. Various changes and modifications can be made within the scope of the technical idea described above, and it is understood that these also belong to the technical scope of the present invention.

For example, the present invention relates to the LC shown in this embodiment.
The present invention is applicable not only to the storage for the D substrate but also to the storage for the semiconductor wafer. Further, the present invention can be naturally applied not only to the case where the substrates are stored in a carrier and stored in the carrier unit, but also to the storage for directly storing the substrates. Further, according to the present invention, not only the storage clean air generator using the catalytic combustion method shown in FIG. 5 but also an apparatus capable of controlling the total concentration of hydrocarbons including methane to 10 ppb or less, Various devices can be used. Further, according to the present invention, the storage clean air generator using the activated carbon filter shown in FIGS. 6 to 10 or the storage clean air generator using the fluidized bed adsorption tower using the activated carbon filter medium shown in FIG. Not limited thereto, various devices can be used as long as the device can be controlled so that the contact angle of pure water drop or the surface resistivity on the surface of the clean material can be maintained to be substantially the same as that immediately after cleaning.

FIGS. 14 and 1 show an evaluation device for directly evaluating the degree of organic substance contamination on the substrate surface in the storage space.
The sensor is not limited to the evaluation apparatus shown in FIG. 7, and various sensors capable of indirectly measuring organic contamination on the substrate surface can be used. For example, it is also possible to adopt a configuration in which an organic substance contamination on the substrate surface is indirectly estimated and evaluated using a sensor for measuring the amount of organic substances in the air. Furthermore, in the illustrated example, the configuration in which the storage is provided in the clean room is shown,
The storage according to the present invention only needs to be kept in a state of being isolated from a surrounding clean space such as a clean room, and can be installed outside the clean room.

[0064]

As described above, according to the present invention,
The first local clean space for storing clean materials is filled with clean air for storage in which the total concentration of hydrocarbons including methane is controlled to 10 ppb or less, thereby effectively preventing organic contamination on the substrate surface. It is possible to At this time, since no inert gas is used, the storage can be operated safely and at low cost.

Further, according to the present invention, the contact angle of pure water drop on the surface of a clean material, for example, from a catalytic reaction tower, an activated carbon filter, or a fluidized bed adsorption tower is set in a first local clean space for storing a clean material. Since the storage clean air is controlled so that the surface resistivity can be maintained substantially equal to that immediately after the cleaning, organic contamination on the substrate surface can be effectively prevented. At this time, since no inert gas or the like is used, the storage can be operated safely and at low initial cost. In addition, it is also possible to provide fine particle removing means without degassing from itself on the downstream side of clean air generating means such as catalytic reaction tower, activated carbon filter, fluidized bed adsorption tower, etc., to minimize the fine particles and impurity gas in the generated clean air. It is possible.

Further, the first local clean space is divided into a storage space for storing clean materials and a buffer space, and organic matter derived from the atmosphere of the surrounding clean space is mixed into the storage space when the materials are carried in and out. Therefore, it is possible to construct a storage suitable for storing semi-finished clean materials that are frequently loaded and unloaded.

Further, in the second local clean space,
By observing the degree of organic surface contamination by the clean air for storage in the first local cleaning space where the clean materials are stored by the evaluation device over time, the organic contamination in the first local cleaning space progresses. In addition, before the stored material is contaminated with organic matter and the yield of products is reduced, it is possible to take measures for organic matter contamination.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of an embodiment of a clean material storage according to the present invention.

FIG. 2 is a side view of the clean material storage shown in FIG.

FIG. 3 is a side view of the clean material storage shown in FIG.

FIG. 4 is a schematic plan view of another embodiment of the clean material storage according to the present invention.

FIG. 5 is a configuration diagram showing an example of a storage clean air generation device applicable to the clean material storage shown in FIG. 1;

6 is a configuration diagram showing an example of a storage clean air generation device applicable to the clean material storage shown in FIG. 1;

FIG. 7 is a schematic exploded view showing an example of a filtration filter applicable to the storage clean air generating apparatus shown in FIG. 6;

8 (a) is a schematic perspective view after assembling the filter shown in FIG. 7, and FIG. 8 (b) is a schematic view of a metal frame used for the filter shown in FIG. 7; FIG.

FIG. 9 is a schematic exploded view showing another example of a filtration filter applicable to the storage clean air generation device shown in FIG. 6;

FIG. 10 is a schematic configuration diagram showing another example of a filtration filter applicable to the storage clean air generation device shown in FIG.

11 is a configuration diagram showing another example of the storage clean air generation device applicable to the clean material storage shown in FIG. 1. FIG.

FIG. 12 is a schematic plan view of another embodiment of a clean material storage according to the present invention.

FIG. 13 is a schematic plan view of still another embodiment of the clean material storage according to the present invention.

FIG. 14 is a schematic configuration diagram showing an embodiment of an evaluation device applicable to a clean material storage according to the present invention.

15A and 15B are plan views showing a configuration of an electrode formed on a substrate applicable to the evaluation apparatus of FIG. 14, wherein FIG. 15A shows a state of a front surface thereof, and FIG. 15B shows a state of a rear surface thereof. .

FIG. 16 is a graph showing the relationship between the amount of organic substances attached to the surface of a glass substrate (carbon / silicon ratio) and the rate of increase in surface resistivity.

FIG. 17 is a schematic configuration diagram showing another embodiment of the evaluation device applicable to the clean material storage according to the present invention.

FIG. 18 is an explanatory diagram showing a relationship between a droplet dropped on a substrate surface and a contact angle.

FIG. 19 is a graph showing the relationship between the amount of organic substances attached to the surface of a glass substrate (carbon / silicon ratio) and the contact angle.

FIG. 20 is a schematic configuration diagram showing one embodiment of a backup mechanism applicable to a clean material storage according to the present invention.

FIG. 21 is a schematic configuration diagram showing another embodiment of a backup mechanism applicable to a clean material storage according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Storage space (1st local clean space) 12 Clean room (surrounding clean space) 14 Partition wall 16 Front room (buffer space) 18 LCD board 20 Transport room 22 Storage room 26 Carrier 32 Air supply system 34 Exhaust system 36 Clean air for storage Generator 38 Partition wall 42 Stocker 46 Air supply system 50 Exhaust system 72 Controller 100 Evaluation device 200 Evaluation device

Continued on the front page F term (reference) 3F022 AA08 BB09 CC02 EE05 FF01 JJ11 KK20 QQ00 5F031 CA02 CA05 DA01 DA17 FA02 FA03 GA48 JA01 JA10 JA45 JA46 JA47 NA03 NA04 NA07 NA11 NA16

Claims (4)

[Claims] 1. A clean material storage configured as a first local clean space installed in a peripheral clean space maintained at a first cleanliness level and separated from the peripheral clean space. A storage clean air generating means for controlling the total concentration of hydrocarbons including methane to be 10 ppb or less and generating storage clean air that is maintained at a second cleanliness level that does not contain fine particles; Air supply means for supplying the storage clean air to the storage space in the local clean space,
Storage room for clean materials. 2. The first local cleaning space includes the storage space and a buffer space interposed between the storage space and the surrounding cleaning space, and the air supply unit includes the storage cleaning space. The storage room for clean materials according to claim 1, wherein an air flow of air is sent from the storage space to the buffer space. 3. An evaluation device having a first local cleaning space and a second local cleaning space isolated from the surrounding cleaning space is provided, and the evaluation device is provided in the second local cleaning space via a gas introducing means. 3. The method according to claim 1, wherein the clean air for storage in the first local clean space is introduced into the first local clean space to evaluate a degree of organic matter contamination in the first local clean space. Storage room for clean materials. 4. The evaluation device monitors whether or not the amount of organic contaminants on the surface of a clean material disposed in the first local clean space is kept below an allowable value. The clean material storage according to claim 3.