JP2003071290A - Detoxifier for removing special gas and method for removing special gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a detoxifier for removing a special gas which is reduced in the adverse effect of water in a dry detoxifier, can reliably removes a special gas in which water coexists, especially, a low-concentration special gas leaked into the air containing much water, and to provide a method for removing the special gas. SOLUTION: The detoxifier is the one based on a manganese oxide and containing 0.1-10 wt.%, based on the manganese oxide, at least one simple metal selected from gold, platinum, silver, palladium, and rhodium or a compound thereof. Even when the detoxifier removes the special gas from the objective containing the special gases and water, it can remove the special gases from the objective without being adversely affected by the water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detoxifying agent for removing a special gas and a method for removing a special gas, and more particularly, to a special gas capable of efficiently removing a low-concentration special gas contained in a gas containing water. A harmful agent and a removal method.

[0002]

2. Description of the Related Art Special gases used in semiconductor manufacturing processes include silane (SiH ₄ ) and arsine (As).
H ₃ ), metal hydrides such as phosphine (PH ₃ ), dichlorosilane (SiH ₂ Cl ₂ ), boron trifluoride (B
F ₃₎ as a halide, such as, a human body has been used many gases having the property of spontaneous combustion with toxic gases or in air to, after using these special gases, allowable concentration of these It is stipulated by law that it should be removed up to the maximum. The most widely used method of removing these special gases is a method of adsorbing and removing the special gas to a solid substance called a harmful agent, which is generally called a dry method.

A wide variety of detoxifying agents are used in the dry method depending on the gas to be detoxified and the gas conditions used. For example, a harm-removing agent in which sodium hydroxide aqueous solution and potassium permanganate are supported on diatomaceous earth and a harm-removing agent supporting ferric chloride aqueous solution have been used even after a considerable history. Since these harmful agents contain a large amount of water, they are sometimes called semi-dry type. These abatement agents are inexpensive and
Although it has the advantage of low running cost, it has a problem in maintaining performance because it has a property of easily evaporating water.

Further, a method of adsorbing and removing a special gas with activated carbon is also common, and a method called impregnated activated carbon in which performance is improved by supporting a small amount of a reactant or catalyst on activated carbon is also known. These detoxifying agents have the merit that they are also cheap, but there are cases where special gas is physically adsorbed, and the detoxifying cylinders filled with the detoxifying agents are insufficiently airtight, or if oxygen is removed from the upstream side. When the contained gas, for example air, flows in, if the physically adsorbed component has a spontaneous ignitability, it may ignite, which may cause an accident that the activated carbon itself burns, and it is necessary to take sufficient measures. There is.

Detoxifying agents that have been widely used in recent years are oxides of metals such as iron, copper, aluminum, manganese, calcium and sodium, and the detoxifying agents made of these oxides react with special gas. It has a mechanism to remove special gas. These features include the fact that the amount of special gas that can be processed per unit volume is remarkably large, and the contact efficiency between the special gas and the agent is high, so that the abatement device can be made compact. The metal oxide-based harmful agents, including the activated carbon-based harmful agents, are also called dry type harmful agents because they have a low water content.

[0006]

However, as a demerit of the above-mentioned dry type harmful remover, there is a problem that the water generated by the reaction is adsorbed by the agent on the downstream side of the reaction zone and the reaction efficiency decreases with time. is there. In addition, when the special gas leaked to the atmosphere is removed, if the concentration of water contained in the atmosphere is high, it may interfere with the reaction between the special gas and the abatement agent, resulting in poor processing efficiency. The same can be said for activated carbon-based detoxifying agents, and under normal circumstances, measures are taken not to expose it to the atmosphere, and in some cases a dry gas is constantly passed through the agent to maintain a dry state. However, the system becomes complicated, and its maintenance and management are troublesome and costly.

On the other hand, in a semiconductor manufacturing factory or the like that uses a special gas, when a container (cylinder) filled with a special gas is stored in a warehouse, or when the cylinder is transported from the warehouse to a place of use, the cylinder is a cylinder. When installed in a cabinet and supplied to semiconductor manufacturing equipment, etc., when consuming special gas in semiconductor manufacturing equipment, etc., when introducing special gas-containing exhaust gas discharged from semiconductor manufacturing equipment, etc. into abatement equipment, When the exhaust gas of the abatement system is treated by the scrubber, it is required to take into consideration the case where the special gas leaks to the atmosphere at each stage such as. Since the gas to be treated in such a case contains a large amount of moisture in the atmosphere, a method capable of performing a reliable removal treatment with little influence of moisture is needed.

In view of the above, the present invention suppresses the influence of moisture in the dry type harmful remover and surely removes the special gas coexisting with the moisture, especially the low concentration special gas leaking into the atmosphere containing a large amount of moisture. It is an object of the present invention to provide a special gas removing harmful agent and a special gas removing method.

[0009]

In order to achieve the above object, the harmful gas removing harmant of the present invention contains manganese oxide as a main component, and is at least one of gold, platinum, silver, palladium and rhodium. 0.1 to 10% by weight with respect to the manganese oxide is added.

The special gas removing method of the present invention is a method for removing the special gas contained in the target gas containing the special gas and moisture, wherein the target gas is mainly manganese oxide. As a component, at least one elemental metal selected from gold, platinum, silver, palladium, and rhodium, or a metal compound thereof is used in an amount of 0.1 to 10 with respect to the manganese oxide.
It is characterized in that it is brought into contact with a harmful agent added by weight%.

Further, the manganese oxide used in the present invention is characterized by being manganese (III) oxide or manganese (IV) oxide.

As described above, by adding a specific metal additive to the dry type harm-removing agent containing manganese oxide as a main component, the moisture resistance of the harm-removing agent can be improved, and the dry type harm-removing agent can be improved. It is possible to prevent the treatment performance of the agent from being deteriorated by moisture. As a result, the special gas that has leaked to the atmosphere can be reliably removed.

As the special gas to be removed, silane is used.
(SiH_Four), Disilane (Si_TwoH ₆), Arsine (A
sH_Three), Phosphine (PH_Three), Diborane (B
_TwoH₆), Hydrogen selenide (H_TwoSe), German (Ge)
H_Four) And other metal hydrides, and dichlorosilane (SiH_Two
Cl_Two), Boron trifluoride (BF_Three), Hydrogen fluoride (H
F), hydrogen chloride (HCl), hydrogen bromide (HBr), fluorine
Elementary (F_Two), Chlorine (Cl_Two), Bromine (Br_Two) Etc. halo
Examples thereof include genides and halogens.
The main component of the processing target gas is exhausted from the semiconductor manufacturing process.
Various exhaust gases used and argon, which is often used as a purge gas
In addition to various industrial gases such as nitrogen and nitrogen, the atmosphere (air) is also included.
It

As the manganese oxide, various manganese oxides can be used as long as they can remove the special gas, but usually manganese (III) oxide (dimanganese trioxide: Mn ₂ O ₃ ) Or manganese (IV) oxide (manganese dioxide: MnO ₂ ) is preferably used alone or in an appropriate mixture. In particular, manganese (III) oxide is
The effect of improving the moisture resistance property by the addition of the metal simple substance or the additive composed of the metal compound is large, and when the water content in the gas to be treated is high, for example, a high-humidity gas having a humidity of 80% is a sufficient special gas. Removal performance can be obtained.

The metal compounds of gold, platinum, silver, palladium, and rhodium, which serve as additives, include hydroxides such as fluorides, chlorides, bromides, and iodides of these metals. , Oxides, sulfides, and further carbonates, nitrates, nitrites, sulfates, sulfites, chlorates, perchlorates, bromates, iodates, periodates, borate, acetic acid Salts, arsenates, phosphates, chromates, cyanides, thiosulfates, oxalates, thio complex salts, thiosulfato complex salts, sulfite complex salts, ammonia complex salts, organic salts, ammine complex salts, pyridine complex salts, phenanthroline Complex salt, dipyridyl complex salt, picolinic acid complex salt,
Various complex salts such as a fluoro complex salt, a periodate complex salt, a telluric acid complex salt, and an ethylenepiguanide complex salt can be used.

The amount of these metal additives added varies depending on the type of metal or metal compound, but is 0.1 to 10% by weight with respect to the harmful agent containing manganese oxide as the main component.
The optimum range is. The addition amount of this metal additive is 0.1
If it is less than 10% by weight, the effect of adding a metal cannot be exhibited, and if it exceeds 10% by weight, the amount of manganese oxide, which is a main reaction component, is relatively decreased. The processing amount per unit amount decreases. Also,
If the amount of metal is large, there is also a disadvantage that the heat generated by the reaction during the removal process becomes large.

The harm-removing agent obtained by mixing the manganese oxide with a metal additive can be used in a powder state, but it improves the handleability, prevents the powder from scattering, and lengths the breakthrough zone. In order to prevent the heat generation from concentrating locally, it is preferable to mold it into an appropriate size and shape before use. Molding of the abatement agent can be performed by a general method,
It can be molded into an arbitrary size and shape by a method such as extrusion granulation, tumbling granulation, tableting, and crushing. At this time, in order to improve moldability, a general binder may be added in a slight amount. The maximum length of molded products is 1 to 5
A range of 0 mm and a range of the shortest length of 1 to 30 mm are preferable.

Furthermore, it is also possible to use a carrier in which the harmful agent is carried. As the carrier, those generally used can be used, for example, silicon oxide, aluminum oxide, iron oxide, zinc oxide, calcium oxide, nickel oxide, magnesium oxide, zeolite, diatomaceous earth,
Activated carbon, or a mixture of these can be used.

When the special gas in the gas to be treated is removed using such a detoxifying agent, the detoxifying agent is filled in an appropriate tube (detoxifying tube), and the inside of the detoxifying tube is filled. The gas to be treated may be circulated. The use temperature of the detoxifying agent is usually normal temperature, and there is no particular problem as long as it is in the range of -10 to + 50 ° C.

[0020]

Example 1 Comparative Example 1 A column made of stainless steel having an inner diameter of 50 mm, in which thermocouples were inserted at intervals of 5 cm, was filled with a harmful agent consisting only of MnO ₂ formed into a spherical shape having a diameter of 3 mm so that the filling height was 200 mm. . At the outlet of this column, a gas monitor for SiH ₄ (TG-4000 manufactured by Bionics Instruments Inc.)
Installed. Next, air containing 0.5% SiH ₄ (humidity 70%, temperature 20 ° C.) was applied from above the column at 1.2 min / min.
When the solution was circulated in liters, after 20 minutes, the gas monitor detected that the outlet concentration of SiH ₄ exceeded the allowable concentration (5 ppm).

Example 1 The same as Comparative Example 1 except that 5% by weight of Au powder was added to MnO ₂ powder and thoroughly mixed, and a harmless agent formed into a spherical shape having a diameter of 3 mm was used. The removal treatment of SiH ₄ was performed under the conditions. As a result, after 2 hours, SiH ₄
Outlet concentration exceeded the allowable concentration (5 ppm).

Example 2 MnO_TwoInstead of Mn_TwoO_ThreeExample except that was used
SiH under the same conditions as 1 _FourWas removed. That conclusion
After 3 hours, SiH_FourThe outlet concentration of is the allowable concentration
(5 ppm).

Example 3 G3: Air containing 0.5% SiH ₄ (humidity 70%, temperature 20 ° C.) G2: Nitrogen containing 0.5% SiH ₄ (no water content) G3: Four types of air containing 0.5% PH ₃ (humidity 70%, temperature 20 ° C.) G 4: air containing 0.5% AsH ₃ (humidity 70%, temperature 20 ° C.) were prepared. In addition, as the main component of the harmful agent, Mn
O ₂ and Mn ₂ O ₃ are used respectively, and a harm-removing agent obtained by adding a predetermined amount of various metal simple substances such as gold, platinum, silver, rhodium, and palladium and silver oxide (Ag ₂ O) as a metal compound thereto. It was used to remove the special gas. The other conditions were the same as in Comparative Example 1 and Examples 1 and 2 above. Table 1 shows the results of measuring the breakthrough time of each harmful agent.

[0024]

[Table 1]

Example 4 5 wt% of Ag ₂ O powder was added to Mn ₂ O ₃ powder and mixed well, and the harmful agent formed into a spherical shape having a diameter of 3 mm was placed in a stainless steel column having an inner diameter of 50 mm. Filling height is 2
It was filled so as to be 00 mm. Air containing 0.5% each of the special gases shown in Table 2 (humidity 70%, temperature 20 ° C.) was passed through this column at 1.2 liters per minute, and the gas monitor installed at the column outlet provided each special gas. The gas outlet concentration was measured, and the breakthrough time of each was measured. The results are shown in Table 2.

[0026]

[Table 2]

[0027]

As described above, according to the present invention,
Since various special gases can be removed almost without being affected by water, special gas removal treatment is required even if water is generated in the reaction or if the gas to be processed contains water. It can be done reliably. Therefore, the removal process of the special gas leaked to the atmosphere containing a relatively large amount of water can be reliably and efficiently performed.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B01J 23/44 H01L 21/205 23/46 311 B01D 53/34 120A H01L 21/205 53/36 Z (72 ) Inventor Shuichi Ozeki 1-16-7 Nishishinbashi, Minato-ku, Tokyo Nihon Oxygen Co., Ltd. (72) Inventor Manyuki Daiki 1-16-7 Nishishinbashi, Minato-ku, Tokyo Nihon Oxygen Co., Ltd. (72) Inventor Hiroyuki Ono 1-16-7 Nishi-Shimbashi, Minato-ku, Tokyo Nippon Oxygen Stock F-term within the company (reference) 4D002 AA18 AA22 AA26 AA27 AA28 AC10 BA03 DA11 DA24 DA25 GA01 GB08 4D048 AA11 AA30 BA28X BA30X BA31X BA33X BA34X BA41X BC01 EA04 4G066 AA02B AA15B AA26B AA28B CA21 CA31 CA32 CA41 4G069 AA03 BB02A BB02B BB04A BB04B BC32A BC32B BC33A BC33B BC62A BC62B BC71A BC71B BC72A BC72B BC75A BC75B CA11 CA19 FC08 AC02 AC045 AC0 5 BB20 EG08

Claims (4)

[Claims] 1. A manganese oxide as a main component, and at least one metal simple substance selected from gold, platinum, silver, palladium, and rhodium, or a metal compound thereof is 0.1 to 10 weight% with respect to the manganese oxide. % Additive for removing special gas, characterized by being added. 2. The manganese oxide is manganese oxide (I
II) or manganese (IV) oxide, The detoxifying agent for removing special gas according to claim 1. 3. A method for removing the special gas in a process gas containing a special gas and moisture, wherein the process gas is mainly composed of manganese oxide, gold, platinum,
At least one elemental metal selected from silver, palladium, and rhodium, or a metal compound thereof is brought into contact with a detoxifying agent added in an amount of 0.1 to 10% by weight with respect to the manganese oxide. Removal method. 4. The manganese oxide is manganese oxide (I
II) or manganese (IV) oxide.