JP3227601B2 - Harmful exhaust gas abatement agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an abatement agent used for removing harmful exhaust gas discharged from a semiconductor manufacturing plant or the like.

[0002]

2. Description of the Related Art In a semiconductor manufacturing plant, harmful exhaust gas containing harmful components such as arsine, phosphine, silane, dichlorosilane and tertiary butyl arsine is discharged. Because these ingredients are explosive or harmful to the human body,
Must be detoxified before release to atmosphere.

[0003] Therefore, as a treating agent for detoxifying the harmful exhaust gas, for example, Japanese Patent Publication No. 3-64166,
3-64167, 4-17082, 4-19
No. 886 and the like, copper oxide (Cu
O) and various other metal oxides have been proposed as a main component of the removal agent.

[0004]

However, the conventional remover containing a metal oxide such as copper oxide as a main component has a small ability to remove silane. The specific surface area must be increased by supporting the carrier on a carrier such as alumina, and the production of the removing agent itself is troublesome.

[0005] Under such circumstances, the present applicant has previously proposed a removing agent containing crystalline cupric hydroxide as a main component (Japanese Patent Application No. 5-56653). This removing agent (hereinafter, referred to as a copper hydroxide agent) is excellent not only in removing arsenic-based arsine and phosphorus-based phosphine but also in removing silicon-based harmful components such as silane. It has the effect of removing harmful components in a larger amount than conventional metal oxide-based removers (hereinafter referred to as metal oxide agents). In some cases, the amount of the harmful components remaining in the resin was larger than that treated with the metal oxide agent.

Accordingly, the present invention provides a harmful exhaust gas elimination method and harmless agent which can remove a large amount of harmful components and can surely remove harmful components to a predetermined concentration or less even under various conditions. It is intended to be.

[0007]

Means for Solving the Problems In order to achieve the above object, the harmful exhaust gas abatement agent of the present invention comprises crystalline cupric hydroxide (hereinafter, referred to as copper hydroxide remover) and metal oxide ( Hereinafter, referred to as a metal oxide remover).

In the present invention, crystalline cupric hydroxide (Cu (OH) ₂ ) as a main component may contain cuprous hydroxide. Cupric hydroxide is classified into crystalline one and amorphous one, but crystalline one has higher stability against temperature, so that it can be used stably and the concentration of harmful components is lower. High removal efficiency even when the reaction heat is high.

The conventional removing agent containing copper oxide as a main component sometimes contains a trace amount of cupric hydroxide as a residue in the process of producing copper oxide. In the agent, the cupric hydroxide remains as an impurity to the last, as in the present invention,
It is essentially different from the one used as the main component of the remover.

The metal oxides include cuprous oxide,
Cupric oxide, magnesium oxide, calcium oxide, titanium dioxide, chromium oxide, manganese dioxide, ferrous oxide,
Many types of metal oxides, such as nickel oxide, zinc oxide, aluminum oxide, and silicon dioxide, can be mentioned.

The harmful components targeted by the present invention are volatile inorganic hydrides, volatile inorganic halides, organometallic compounds and the like used in semiconductor manufacturing plants and the like. Examples of the volatile inorganic hydride include diborane, silane, disilane, germane, ammonia, phosphine, arsine, hydrogen sulfide, and hydrogen selenide. Examples of the volatile inorganic halide include boron trifluoride. , Boron trichloride, silicon tetrafluoride, dichlorosilane, trichlorosilane, silicon tetrachloride, trichloroarsine, tungsten hexafluoride, fluorine, chlorine, hydrogen fluoride, hydrogen chloride, hydrogen bromide, etc. Can be mentioned.

Further, as the organometallic compound, dimethylzinc, diethylzinc,
Trimethylaluminum, triethylaluminum, trimethylgallium, triethylgallium, trimethylindium, triethylindium, tetramethyltin, tetraethyltin, tertiarybutylphosphine, trimethylarsine, triethylarsine, tertiarybutylarsine, etc. as those containing an alkoxide group; Dimethoxyzinc, tributoxygallium, trimethoxyboron, triethoxyboron, tetramethoxysilane, tetraethoxysilane, tetramethoxygermane, tetraethoxygermane, tetratertiarybutoxytin, trimethoxyphosphine, triethoxyphosphine, trimethoxyarsine, trimethoxy Ethoxyarsine, tetraethoxyselenium, tetramethoxytitanium, tetraethoxytitanium, tetraiso Ropokishichitan, tetraisopropoxy zirconium, tetra-tertiary-butoxy zirconium, pentamethoxy tantalum, pentaethoxytantalum etc. can be mentioned, respectively.

[0013]

[Action] The amount of copper hydroxide remover used to remove harmful components in exhaust gas is large, but depending on the use conditions,
The residual amount of the harmful component may be larger than that of the metal oxide remover. On the other hand, the metal oxide remover can remove harmful components to a very small amount, but the amount of treatment until breakthrough is small.

When the harmful exhaust gas is brought into contact with an abatement agent containing a copper hydroxide remover and a metal oxide remover as in the abatement agent of the present invention, the harmful exhaust gas is compared with the case where each is used alone. The harmful components therein can be efficiently removed. Normally, when two components of the remover are mixed, the average value of the two appears to be the removal ability, but in the case of the abatement agent of the present invention, a synergistic effect occurs, and the copper hydroxide remover or the metal oxide remover is used. The processing amount increases as compared with the case of using each alone.

When cupric hydroxide reacts with the gas to be removed, the color changes from blue to black. Therefore, the filling cylinder (column) is made of a transparent material or a transparent window is provided in the column. For example, it can be observed that the blue / black breakthrough front moves from the upstream side to the downstream side as the reaction proceeds. Therefore, the breakthrough of the copper hydroxide removing agent can be known in advance without using any special detecting means, and the removing agent (harmless agent) can be accurately replaced. Moreover, since the copper hydroxide remover can exhibit sufficient processing capacity even with a small specific surface area,
For example, it can be used in the form of a tablet, and production is easy.

[0016]

EXAMPLES Examples and comparative examples of the present invention will be described below.

First, the following were prepared as a copper hydroxide remover, a metal oxide remover, and a test gas. In addition, a molded product is a diameter of 1.0 mm and a length of 5 mm by an extrusion molding machine.
It was molded into a pellet of mm. In addition, the measurement of the treatment capacity of the remover (harmless agent) is based on the limit of use of the remover when the amount of harmful components contained in the gas after the removal reaches the following allowable concentration. The amount of the harmful component gas to be processed per 1 kg of the removing agent was calculated from the amount of the test gas introduced until the test gas was reached.

Copper hydroxide remover A: molded product of commercially available crystalline cupric hydroxide powder (manufactured by Kanto Kagaku) B: 1 mol / l copper sulfate solution and 1 mol / l sodium hydroxide solution A molded product after drying a precipitate (crystalline cupric hydroxide) obtained by mixing the above. Metal oxide remover a: A molded product of commercially available cupric oxide powder (manufactured by Kanto Chemical) b: Copper nitrate , Aluminum nitrate, and sodium carbonate are mixed to obtain a precipitate obtained by calcining a precipitate obtained by calcining the precipitate, whereby cupric oxide is supported on alumina (the amount of cupric oxide is about 30 wt. %) C: molded product of commercially available silver oxide (manufactured by Kanto Kagaku) d: molded product of commercially available manganese dioxide (manufactured by Kanto Kagaku) Test gas harmful component Permissible concentration Silane 5 ppm Arsine 0.05 ppm Phosphine 0.3 ppm Tertiary butylarsine (T A) allowable concentration of 0.025 ppm (TBA is converted value from the allowable concentration of arsenic containing) concentration and flow rate G _1:. Nitrogen Base hazardous component gas concentration of 1%, a flow rate 1 liter / min G _2: Nitrogen Hazardous component gas concentration 5% at base, flow rate 5 liter / min

Comparative Example 1 The above copper hydroxide removers A and B and the metal oxide removers a and b
Was used alone, and the silane treatment capacity was measured. In addition, each remover was packed into a column having an inner diameter of 43 mm to a packed layer length of 300 mm. Table 1 shows the results.

Example 1 An abatement agent obtained by mixing a copper hydroxide remover A and a metal oxide remover b at a volume ratio of 5: 1 was used in the same manner as in Comparative Example 1 to obtain an inner diameter of 43%.
The column was packed with a packed bed length of 300 mm in a column of mm, and the silane treatment capacity was measured. Table 1 shows the results.

[0021]

[Table 1]

In Table 1 above, the processing capacity is a value relative to the amount of the removing agent (cupric hydroxide and / or copper oxide) used, and the amount in parentheses is the total amount of the removing agent used (alumina carrier or dehydrating agent). Per weight).

As shown in Table 1, the removers A and B made of copper hydroxide are more abundant than the removers a and b made of copper oxide.
Even when used alone, the processing capacity of silane is remarkably large. The detoxifying agent obtained by mixing a metal oxide removing agent b hydroxide copper removal agent A, as test gas G _1, when the silane concentration is small low flow rate, the effect of mixing the two is less recognized Never, but as the test gas G _2, when the concentration is high flow rate is large, it can be seen that the processing performance is improved. Because the value for the amount of all removers in parentheses is also excellent,
By mixing both of them, the total amount of the removing agent can be reduced to reduce the size of the apparatus or extend the life of the abatement cylinder.

[0024]

As described above, according to the present invention,
Exhaust gas containing harmful components, especially arsine, phosphine, silane, dichlorosilane, emitted from semiconductor manufacturing plants,
Harmful exhaust gas containing harmful components such as tertiary butyl arsine can be efficiently removed.

Continuation of the front page (72) Inventor Fumihisa Endo 3054-3 Shimokurosawa, Takane-cho, Kita-Koma District, Yamanashi Prefecture Inside Nippon Sanso Corporation (56) References JP-A-3-12219 (JP, A) (58) Fields investigated ( Int.Cl. ⁷ , DB name) B01J 20/00-20/34

Claims (1)

(57) [Claims] 1. A harmful exhaust gas abatement agent comprising crystalline cupric hydroxide and a metal oxide.