JP3288148B2 - Method and apparatus for preventing contamination of substrate or substrate surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and apparatus to prevent contamination of the substrate or substrate surface in between empty, in particular raw materials in advanced industries such as semiconductor manufacturing and liquid crystal manufacturing, semi-finished products, the substrate of the product In the prevention of contamination of the substrate or the surface of the substrate, the contamination of the surface of the substrate or the substrate is properly performed by detecting the hydrocarbon as a contaminant by releasing iodine.

[0002] The fields of application of the present invention include, for example, (1) prevention of contamination of wafers in a semiconductor manufacturing process, (2) prevention of contamination of glass substrates in a liquid crystal manufacturing process, (3) prevention of substrate contamination in a precision machine manufacturing process, It is. Examples of locations to which the method and apparatus for preventing contamination of the present invention are applied include spaces in a clean room such as a semiconductor manufacturing plant, a liquid crystal manufacturing plant, and a precision machine manufacturing plant, for example, a safety cabinet, a clean box, a valuable storage, and a wafer storage. Storage space, closed transfer space for valuables, clean closed space in the presence of various gases or under reduced pressure or vacuum, transfer space, space containing gas supplied to the cleaning device, space containing air supplied to the air knife. is there.

[0003]

2. Description of the Related Art The prior art will be described below by taking air purification in a clean room in a semiconductor manufacturing plant as an example.
In a clean room, fine particles (particulate matter)
Gaseous substances such as hydrocarbons (HC) at extremely low concentrations other than methane in the air due to automobile exhaust gas and the like pose a problem as pollutants. In particular, H. C is a gaseous harmful component and must be removed because it has a very low concentration in normal air (indoor air and outside air). Also,
Various solvents (alcohols, ketones, etc.) generated in the operation in the clean room also pose a problem as pollutants.

That is, if the above-mentioned contaminants (fine particles and gaseous contaminants) deposit on the substrate surface of a wafer, semi-finished product, or product, the substrate surface is easily damaged, and the productivity (yield) of semiconductor products is reduced. It is necessary to remove contaminants because they cause this. Both the fine particles and the gaseous substance increase the contact angle on the substrate surface. C has a high tendency to increase the contact angle. Here, the contact angle is a contact angle of wetting by water, and indicates a degree of contamination of the substrate surface. That is, when a hydrophobic (oil-based) substance adheres to the substrate surface, the surface repels water and becomes hard to wet. Then, the contact angle between the substrate surface and the water droplet increases. Therefore, the contamination degree is high when the contact angle is large, and low when the contact angle is small.

[0005] Conventional clean room air purification methods or apparatuses therefor are roughly classified into (1) a mechanical filtration method (such as a HEPA filter), (2) electrostatically collecting fine particles, and using a high voltage. There is a filtration method using a charged or conductive filter (such as a HESA filter). All of these methods are aimed at removing fine particles, such as hydrocarbons other than methane (HC).
It has no effect on the removal of gaseous pollutants which increase the contact angle. On the other hand, gaseous pollutants H. As a method for removing C, a combustion decomposition method, an O ₃ decomposition method, and the like are known. However, these methods use extremely low concentrations of H.V. contained in air introduced into a clean room. There is no effect in removing C.

[0006] H. As gaseous harmful components other than C, there are SOx, NOx, HCl, NH _{3 and the} like, and as a removing method thereof, a method utilizing a neutralization reaction or an oxidation reaction using an appropriate alkaline substance or acidic substance, and the like. It has been known. However, these methods have little effect when the concentration of the components is extremely low such as contained in the air introduced into the clean room. H. SOx other than C, N
Ox, HCl, in the harmful components in a conventional atmospheric concentrations, such as NH _3, generally affect less. H. as a gaseous pollutant C is a major contaminant because it is common at any site and affects at normal atmospheric concentrations.

The present inventors have already proposed a method and an apparatus using an adsorbent or an absorbent to prevent the above-mentioned increase in the contact angle, as a method and an apparatus for preventing contamination of the substrate or the substrate surface. (Japanese Patent Application No. 3-341802, Japanese Patent Application No. 4-180538). While these methods and apparatus are effective in some applications, further improvements need to be made to increase their practicality. To increase practicality,
Detects and monitors contaminants that increase the contact angle, prevents the contaminants from coming into contact with raw materials, semi-finished products, and products, and prevents contamination of the substrate or substrate surface (contamination used to prevent contamination). It is necessary to make full use of the material (collection material).

That is, conventionally, pollutants are trapped by the above-described method and apparatus, but the life of the pollutant trapping material can be determined only by the design value determined by the preliminary test. Depending on the operating conditions, contaminants may flow backwards, and the raw materials,
Semi-finished products and products were sometimes damaged, and their service life was not accurately determined. For this reason, the cost is high and the operation is complicated, and there is a need for improvement.

[0009]

The present invention 0005] is to solve the problems described above, with how to detect hydrocarbons traces contained in the gas by simple means, the life of the adsorbent An object of the present invention is to provide a method and an apparatus for preventing contamination of the surface of a base material or a substrate, which detects the presence of the same.

[0010]

In order to solve the above problems SUMMARY OF THE INVENTION The present invention provides detection of hydrocarbons contained trace amounts in a gas
But it can be detected by the change in color tone due to free iodine
Is used in combination with a means for purifying gas .

[0011] In the present invention, the substrate or the substrate surface
A method of preventing contamination of a gas in contact with the base material or substrate, or in more purified in intake Chakuoyobi / or absorbing hand stage
By al dust, particulate concentration class 1000 or less in said gas, after the non-methane hydrocarbon concentration to be less 0.2 ppm, Ri by the exposing said gas to the substrate or the substrate surface, the substrate or when to prevent contamination of the substrate surface
In addition, the process is carried out while detecting and monitoring hydrocarbons in the gas based on a change in color tone accompanying release of iodine.

[0012] In the present invention, the substrate or the substrate surface-fouling
In a dye prevention device, gas that comes in contact with the substrate or substrate
Adsorbing means and / or absorbing means for removing non-methane hydrocarbons to 0.2 ppm or less in the flow path ;
Removal to remove particles until class 1000 or less
And a monitor device for sequentially detecting dust means and detecting hydrocarbons in the gas based on a change in color tone due to liberation of iodine.

Hereinafter, the present invention will be described in detail. In the present invention, the method of detecting hydrocarbons (HC) present in a gas is described in C is detected by the iodine liberation reaction in the presence of C. If it reacts with C to release iodine,
Although any of them can be used, usually, iodine pentoxide is preferable because of its high effect and easy use.

This reaction is according to the following formula (1). H. C + I ₂ O ₅ + H ₂ S ₂ O ₇ → I ₂ + H ₂ SO ₄ + H ₂ O + CO ₂ (1) The free iodine (I ₂ ) of the formula (1) is detected by detecting a change in color tone by an appropriate method. be able to. For example, I ₂ O ₅ and H ₂ S ₂ O are added to a suitable base material such as glass beads.
₇ is impregnated with H. When C reacts, iodine is released to give a dark brown color, and the change to the dark brown color can be monitored visually or by detecting light absorption (change in absorbance).

The space to which the present invention can be applied means not only under the above-mentioned atmospheric pressure, but also under pressure, under reduced pressure, and under vacuum, and can be implemented similarly. H. in air The C component is said to be a mixture of hundreds or thousands or more of components. It is unknown which component of the C component is involved in increasing the contact angle and to what extent. For this reason, the details of the mechanism for preventing an increase in the contact angle due to the adsorbent and / or the absorbent are unclear, but are considered as follows. That is, H.P. It is presumed that, among the C components, particularly high molecular weight substances and highly active substances have a large effect, and these are effectively adsorbed and absorbed by adsorbents and absorbents.
Collected.

Next, a contaminant collecting material for preventing contamination of the substrate or the substrate surface will be described. In order to remove gaseous harmful components, materials that adsorb and / or absorb these components that increase the contact angle are used. Non-methane hydrocarbons cause pollution at concentrations in normal air (room air and outside air). Also, among various non-methane hydrocarbons,
It is considered that the component that increases the contact angle differs depending on the type of substrate (wafer, glass material, etc.) and the type and properties of the thin film on the substrate.

This contaminant can be collected by using the following collecting material. As the adsorbent, activated carbon, silica gel, synthetic zeolite, molecular sieve, polymer compound (for example, styrene-based polymer, styrene-divinylbenzene copolymer), glass, fluorine compound, metal and the like are used. As the glass material, an oxide glass system, for example, silicate glass or phosphate glass is generally used. As silicate glass, borosilicate glass (main component: Na
_{2 O-B 2 O 3 -SiO} 2) it is formed easily with high adsorption effect and preferable because it is inexpensive. When the glass surface is coated with a metal thin film of Ti, Au, Al, Cr or the like, the adsorption effect is enhanced.

Examples of the fluorine compound include tetrafluoride resin, 4-hexafluoride resin, PFA resin, ethylene trifluoride resin,
Examples include ethylene tetrafluoride-ethylene copolymer, vinylidene fluoride resin, vinyl fluoride resin, graphite fluoride, and Teflon. The shapes of the glass and the fluorine compound used include a filter shape, a fiber shape, a net shape, a spherical shape, a pellet shape, a lattice shape, a rod shape, a pleated shape, and the like. In general, a filter shape is preferable because it has a large adsorption effect. As an example of a molding method in the case of using a filter, there is a method in which a fluorine compound resin is used as a binder and a fibrous glass material is solidified into a filter. When used in such a filter shape, Since the dust removal performance is added to the C removal performance, the filter configuration is simplified. Therefore, incorporating such an adsorbent into a pollution control device is preferable depending on the field of use, the scale of the device, and the shape of the device.

As the metal, for example, Fe, Ag, Ni,
There are Cr, Ti, Au, Pt, powdery, plate-like, sponge-like, linear, fibrous, or those added to an appropriate carrier, such as silica-alumina gel carrying Ag or zirconium phosphate. A shape carrying Ag can be suitably used. Among the above adsorbents, silica gel, synthetic zeolite, polymer compound, glass, fluorine compound, and metal are more preferable because of their high adsorption effect. These adsorbents can be used alone or in appropriate combination of two or more types (Japanese Patent Application Nos. 3-341802 and 4-18005).
No. 38). As described later, the H.V. Since C is considered to be of a plurality of types, the life is prolonged when two or more types of adsorbents are used in combination. That is,
Normally, all H. elegans involved in increasing the contact angle are collected by one type of adsorbent. Because there is a limit in collecting C,
It is effective to use an adsorbent having different adsorption characteristics in an appropriate combination after conducting experiments.

Further, depending on the type of the glass substrate or the surface condition of the substrate, H.V. Since the degree of influence of C differs, appropriate preliminary tests are performed according to the application field, equipment scale, shape, equipment usage conditions, coexisting gas, required performance, economy, etc., and a suitable one is selected from the above adsorbents can do. In addition, depending on the application field and the type of the apparatus, if the air to be treated is dehydrated, dehumidified or dehumidified before the air is passed through the adsorbent, the adsorbing performance of the adsorbent is improved and the service life is extended. For this purpose, a well-known system such as a cooling system, an adsorption system, an absorption system, a compression system, and a system using membrane separation can be used, and the application field, scale, shape, and use conditions (for example, large Preliminary tests are performed as appropriate under pressure or under pressure, and one type or two or more types are appropriately used in combination. As the dehumidification method, it is preferable to use a method in which dehumidification performance is stably maintained over a long period of time, usually several months to six months or more.

In particular, the cooling type and / or the adsorption type are simple and effective. The cooling type is preferably an electronic dehumidification type or a cooling coil type, and the adsorption type is a simple type (fixed type, rotary type, etc.) for long-term continuous dehumidification while performing dehumidification and regeneration of the dehumidifier itself. It is effective. Silica gel, zeolite, activated carbon, activated alumina, magnesium perchlorate, calcium chloride, and the like can be used as the dehumidifying material by the adsorption method. Among them, silica gel and zeolite are H.I. It is preferable because it has a C removing effect, can be recycled, and can be used for a long time. If dehumidification is performed so that the moisture concentration in the gas to be treated is 50% (RH: relative humidity) or less, preferably 30% (RH) or less, the H.O. The C adsorption performance is improved, and the performance is stably maintained for a long time. The dehumidifying method and the critical moisture concentration are determined by the type, scale, It can be determined by conducting a preliminary test as appropriate according to the type of C removing material, required performance, economy, and the like.

In general, if dehumidification is performed, H.P. C removal performance is stably maintained for a long time. In particular, the performance is remarkably stabilized when a hydrophobic substance such as silica gel or a fluorine compound is used as the adsorbent. On the other hand, when the amount of dehumidification is small or when the moisture concentration of the gas to be treated is low, the dehumidification can be omitted. That is, the dehumidification can be determined by appropriately conducting a preliminary test according to the type of the adsorbent, the application field of the apparatus, the moisture concentration in the gas to be treated, the scale, shape, required performance, economy, etc. of the applied apparatus. When using the adsorbent, besides the above-mentioned method (with dehumidification), PSA
(Pressure swing adsorption) and TSA (thermal swing adsorption)
Thereby, regeneration of the adsorbent can be performed simultaneously.

H. C-absorbing material has a low concentration of H.I. Any substance that can react with C and immobilize it can be used. Generally, a reaction with Cr ⁶⁺ in the presence of H ₂ SO ₄ and a reaction with I ₂ O ₅ in the presence of H ₂ S ₂ O ₇ can be used. The former is a low molecular weight H. C, the latter being high molecular weight H. Effective for C. For example, it used by impregnating a salt aqueous solution containing hexavalent chromium H ₂ SO ₄ acid on the surface of the carrier such as zeolite or alumina glass beads or appropriate shape (e.g., pellets). The term “absorption” refers to absorption by a chemical reaction. Where H
The reaction with I ₂ O ₅ in the presence of ₂ S ₂ O ₇ is the same as the reaction used in the above-mentioned monitor. In this case, H. Since the collection and monitoring of C can be shared, it is preferable depending on the application device.

The adsorbent and / or the conditions for using the adsorbent can be determined by appropriate preliminary tests depending on the field of application of the apparatus of the present invention, the scale of the apparatus, the shape, the required performance, and the like.
The space velocity (SV) of the air to be treated in the apparatus is usually 100 to
20,000 (h ^-1 ), preferably 100 to 5000 (h
^-1 ). The dust removing means may be of any type as long as it can remove fine particles in the air to a low concentration. Normal,
A well-known dust filter that efficiently collects fine particles to a low concentration is used. Generally, HEPA filter, ULPA
Filters and electrostatic filters are preferred because they are simple and effective. Usually, one or more of these filters are used in appropriate combination. By removing the fine particles, the fine particle concentration is reduced to class 1000 (1000 particles / f.
t ³ ) or less, preferably class 100 or less. Here, the class is a unit of fine particle concentration, and represents the number of fine particles in 1 ft ³ .

In general, substances that contaminate the substrate or the substrate surface and increase the contact angle include (1) SOx, NO
x, harmful gases such as HCl, NH ₃ , (2) fine particles,
(3) H. C, and as a result of the study by the present inventor, it has been found that in normal air (in the ambient air in a normal clean room) or in N ₂ used in a clean room such as a semiconductor manufacturing plant or a liquid crystal manufacturing plant, the contact is made. For the corner, the fine particles and H. The influence of C is large. That is, generally, SOx
, NOx, HCl, and NH ₃ have little effect on the increase in contact angle at normal air concentration levels. Therefore, dust removal and H. The effect is obtained by removing C.

As described above, the gaseous contaminants on the substrate or the substrate surface are H. Since C is the main component, the H.C. By detecting and monitoring C by the means of the present invention, the life of the contaminant trapping material can be accurately known. The installation position of the reactant that can be monitored by liberation of iodine can be set at an appropriate position, for example, at one position at the center or the like, or at a plurality of positions at the center and rear. Also, only a small part of the inside of the pollution control device or a separate flow path from the pollution control device is installed,
Alternatively, it can be used by being mixed with an adsorbent or an absorbent. The amount, location, and method of use of the reactant can be determined by conducting preliminary tests as appropriate according to the applied device, scale, field, device shape, type of contaminant trapping material, required performance, and the like.

[0027]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. Embodiment 1 FIG. 1 shows an example in which the method of the present invention is applied to purification of air supplied to a wafer storage in a semiconductor manufacturing factory. In FIG. 1, reference numeral 1 denotes a class 10000 clean room, in which air 2 in the clean room includes a dehumidifier 3, an adsorbent 4 that adsorbs gaseous harmful components (in this example, mainly HC) that increase the contact angle, and H.I. C is treated in the clean room 1 by a pollution control device 8 including a reactant 5 capable of monitoring iodine liberation, a trapping material 6 for the free iodine, and a dust filter 7. The air 9 that has passed through the apparatus 8 is clean air from which dust and gaseous harmful components have been removed, and is supplied to a wafer storage 10 for storing wafers (substrates).

Next, the processing method will be described with reference to FIG.
First, the outside air 11 in the clean room 1 is processed by the coarse filter 12 and the air conditioner 13. Next, the air is removed by the HEPA filter 14 when entering the clean room 1, and the extremely low concentration H.F. Class 100 where C coexists
The air 15 has a concentration of 00. That is, the extremely low concentration of H. mainly generated from automobiles. Since C is not removed by the coarse filter 12, the air conditioner 13, and the HEPA film 14, it is introduced into the clean room 1. Air 11
H. in The concentration of C is non-methane. 0.5-0.8pp at C
m.

[0029] Moisture (RH 40-60%), fine particles (class 10000), and extremely low concentrations of H. First, the air 2 in the clean room 1 containing C is dehumidified by a dehumidifier (dehumidifier) 3 so that the water content becomes equal to or less than a certain concentration. The dehumidifier of this example is based on an electronic dehumidification method, and is operated so that the humidity (RH 40 to 60%) in the clean room 1 becomes 25 RH% or less. The air after dehumidification is then H.
C. The adsorbent 4 is treated with an ultra low concentration H.I.
C is removed. H. The C adsorbent 4 has a very low concentration of H.O. Any material that removes C may be used. In this example, silica gel is used as the adsorbent 4. Thereby, non-methane H. in the air. C is 0.
It is removed to a concentration of 1 ppm. Silica gel is introduced air 2
If the moisture content is high, the moisture is also adsorbed and the performance is reduced, so the moisture is removed in advance by the dehumidifier 3 as described above.

5 is H. C is a reactant for detecting the life (deterioration) of the trapping material 4. When C flows out, it can be detected and monitored by the release of iodine. The reactant is effluent from the trapping material 4. A material which reacts with C to release iodine, for example, a material obtained by impregnating I ₂ O ₅ and H ₂ S ₂ O ₇ into a suitable base material such as glass beads, can be used. When C reacts, iodine (I ₂ ) is liberated, giving a dark brown color. This change to dark brown can be easily monitored visually or by light absorption (change in absorbance). The life of the C trapping material 4 can be easily known. Reference numeral 6 denotes a free iodine collecting material for preventing free iodine from flowing backward, where iodine is collected. The trapping material 6 may be any as long as it can trap free iodine, and usually activated carbon can be suitably used.

Reference numeral 7 denotes a dust filter, which removes fine particles in the air by a dust filter (dust removing device) 7. The position of the dust removal filter 7 C. The upstream side of the adsorbent 4 or, as in this example, H.O. It can be on the downstream side of the C adsorbent, or on both the upstream side and the downstream side. However, adsorbent 4
Usually, at least one of them is preferably installed on the downstream side as in this example for safety, assuming that fine particles may flow out of the apparatus. The dust filter 7 may be any filter that can efficiently collect fine particles having a concentration of class 10000 in the clean room and fine particles flowing out of the adsorbent. In this example, an ULPA filter is used. The ULPA filter removes particulates down to class 10 or lower.

In this example, H.264 is used. Although C removal is performed by an adsorbent, an absorbent (a reactant with an extremely low concentration of HC) may be used instead of the adsorbent. Further, an adsorbent and an absorbent may be used simultaneously. The positions of the dust filter and the adsorbent with respect to the dehumidifier in this embodiment are described in H.S. There is no limitation as long as the purpose of performing dehumidification in advance in removing C is achieved.

The combination of the method (apparatus) already proposed by the present inventor with the method of the present invention or The use and combination of materials for removing harmful gases other than C can be appropriately selected and used. The conditions for using the dust filter and the adsorbent and / or absorber can be determined as appropriate. That is, these are appropriately determined according to the concentration and type of contaminants (fine particles, HC, and other harmful gases) in the clean room to be used, the type of the applied device, the structure, the scale, the required performance, the efficiency, the economy, and the like. It can be determined by conducting preliminary tests. In the present embodiment, the case where the medium is air has been described. However, it is needless to say that the present invention can be similarly carried out when fine particles or gaseous harmful substances are contained as impurities in other gases such as nitrogen and argon.

Example 2 The apparatus shown in FIG. C was removed. The glass substrate was exposed to the clean air thus obtained, the contact angle was measured, and the correspondence with the color change of the reactant was examined. Moisture concentration in clean room before test condition treatment: 40-60
% Particle concentration in clean room before treatment: Class 10
000 in a clean room before treatment Concentration of C:
0.51 ppm dehumidifier: electronic dehumidifier (Peltier effect method) (manufactured by Shinei Sangyo Co., Ltd.) Dust removing filter: ULPA (manufactured by Nippon Pole Co., Ltd., gas clean filter SGLF6101)

H. C adsorbent: silica gel (medium, SV:
1000h ^-1 ) (manufactured by Fuji Devison Co., Ltd.) Reactant: glass beads impregnated with I ₂ O ₅ and H ₂ S ₂ O ₇ (white, granular) Collector for free iodine: activated carbon fiber (Toyobo Contact angle measuring device: Kyowa Interface Science Co., Ltd., CA-D contact angle meter Moisture measuring device: Electronic humidity sensor, Color change: Visual observation Pretreatment of glass substrate: Washing with detergent and alcohol Later, O ₃
UV irradiation when generated

[0036] shows the relationship between exposure time of the glass substrate and the measured contact angle θ and color change to result air in FIG. In FIG. 2, the thing of the present invention (using a dehumidifier, a dust filter, silica gel, a reactant, and an activated carbon fiber) is indicated by ---, and as a comparison, a change in the contact angle is caused by glass before treatment in a clean room. The measurement was also performed when the substrate was exposed, and is indicated by-●-. The coefficient (detection lower limit of the contact angle) that can detect the contact angle of the contact angle meter used is 3 to 4 degrees, and in the case of the present invention in which a dehumidifier, a dust filter, silica gel, a reactant and activated carbon fiber are used at the same time. In the early stage, the detection limit (↓) was shown.
The concentration of fine particles at the outlet of the apparatus up to an exposure time of 160 hours is less than or equal to class 10 (measurement device: light scattering type particle counter). The concentration of C was 0.1 ppm or less (measuring device: gas chromatograph). The water concentration at the outlet of the dehumidifier was 25 to 30%.

Example 3 In the clean room of Example 2, moisture, fine particles and H.O. were extracted from air in the clean room by the apparatus shown in FIG. 3 (the following dust filter and adsorbent were used). C was removed. The glass substrate was exposed to the clean air thus obtained, the contact angle was measured, and the correspondence with the color change of the reactant was examined. Moisture concentration in clean room before test condition treatment: 40-60
% Particle concentration in clean room before treatment: Class 10
000 in a clean room before treatment Concentration of C:
0.64 ppm dehumidifier: electronic dehumidifier (Peltier effect method) (manufactured by Shinei Sangyo Co., Ltd.)

H. C adsorbent: silica gel (medium, SV:
1000h ^-1 ) (manufactured by Fuji Devison Co., Ltd.) and a filter obtained by forming a fibrous borosilicate glass into a filter on the downstream side of the silica gel using tetrafluororesin as a binder (SV:
10000h ^-1 ) Dust removal filter: The above-mentioned fibrous borosilicate glass is formed into a filter shape and also used as a reactant: Glass beads impregnated with I ₂ O ₅ and H ₂ S ₂ O ₇ (white) Free iodine trapping material: activated carbon fiber (manufactured by Toyobo Co., Ltd.) Contact angle measuring device: manufactured by Kyowa Interface Science Co., Ltd., CA-D type contact angle meter Moisture measuring device: electronic humidity sensor, color change : Visual observation Pretreatment of glass substrate: O ₃ after washing with detergent and alcohol
UV irradiation when generated

[0039] shows the relationship between exposure time of the glass substrate and the measured contact angle θ and color change to result air in FIG. In FIG. 4, the present invention (dehumidifier, dust filter, HC adsorbent, reactant,
(Activated carbon fiber is used) is indicated by-, and for comparison, the change in contact angle is shown by-●-when exposed to air before treatment in a clean room. The concentration of fine particles at the outlet of the apparatus is less than class 10 and non-methane H.I. The concentration of C is 0.1
ppm or less. The moisture concentration at the outlet of the dehumidifier is 2
5-30%. The symbols in FIG. 3 have the same meanings as the same symbols in FIG.

[0040]

According to the present invention, the following effects can be obtained. (1) In preventing contamination of the base material or the substrate surface, H.sub. Monitor C by detecting iodine release (detection)
By doing so, it was possible to monitor (detect) the state of the life (deterioration) of the adsorbent and / or the absorbent due to the contaminants. That is, in an emergency, a high concentration of H.V. Even if C was generated and the adsorbent and / or absorbent deteriorated more than originally expected, the state of this deterioration could be easily grasped.

As a result, it was possible to prevent contaminants from coming into contact with raw materials, semi-finished products, and products. As a result, the adsorbent and / or absorbent for the contaminants could be used up to the limit of the life, and the material was effectively used. (2) According to (1), the practicality of a method and an apparatus for preventing contamination of a substrate or a substrate surface using an adsorbent and / or an absorbent is improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram for explaining a method of the present invention.

FIG. 2 is a graph showing exposure time, contact angle, and color change.

FIG. 3 is a schematic configuration diagram of another pollution control device in FIG. 1;

FIG. 4 is a graph showing exposure time, contact angle, and color change.

[Explanation of symbols]

1: clean room, 2: air, 3: dehumidifier, 4: adsorbent, 5: reactant, 6: collector, 7: dust filter, 8:
Pollution prevention device, 9: clean air, 10: wafer storage, 1
1: outside air, 12: coarse filter, 13: air conditioner, 1
4: HEPA filter, 15: air

──────────────────────────────────────────────────続 き Continuation of the front page (56) References: JP-A-63-67861 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 31/22 B01D 53/72 G01N 31 / 00

Claims (2)

(57) [Claims] 1. A method for preventing contamination of a substrate or a substrate surface.
In the gas in contact with the base material or substrate, to dust from the more clean the intake Chakuoyobi / or absorbing hand stage
Ri, wherein the particle concentration in the gas class 1000 or less, after the non-methane hydrocarbon concentration to be less 0.2 ppm, Ri by the exposing said gas to the substrate or substrate surface, contamination of the substrate or substrate contamination preventing method of the substrate or the substrate surface, characterized in that the hydrocarbon performed while monitoring to detect a change in color tone due to free iodine in said gas upon to prevent. 2. A device for preventing contamination of a substrate or substrate surface.
Te, the flow path through the gas in contact with the base material or substrate, and adsorption unit and / or absorption means for removing the non-methane hydrocarbon until less 0.2 ppm, Class 1 particulate
And a dust removing means for removing until it is less than 000
Together comprising, pollution control device for the substrate or the substrate surface, characterized in that the hydrocarbon in said gas is provided monitor apparatus for detecting a change in color tone due to free iodine.