JP2001029742A - Treating agent for exhaust metal halide gas and treating method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently and safely treat an exhaust gas containing a metal halide gas by composing a treating agent mainly of a solid metallic oxide and at the same time, making the exhaust gas containing the metal halide gas pass through the solid metallic oxide. SOLUTION: For a solid metallic oxide to be used as a main component of the treating agent, almost all kinds of metallic element oxides can be used. Especially MgO, CaO, TiO2 and others are preferable because of their low toxicity, case of handling and low cost. An exhaust gas containing a metal halide gas is treated by making the exhaust gas pass through a filling layer containing at least 10 wt.% or more, preferably 50 wt.% or more solid metallic oxide as the main component. In this case, it is preferable to set the specific surface area of the solid metallic oxide at 0.1 m2/g or more from the viewpoint of improving the gas/solid contact between the solid metallic oxide and the exhaust gas. In addition, in order to upgrade the exhaust gas treating capability of the solid metallic oxide, it is preferable to heat the exhaust gas and is preferable to set the heating temperature at 20-40 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a treatment agent for a metal halogen exhaust gas and a method for treating the same. More specifically, the present invention relates to a dry gas treating agent for contact-treating an exhaust gas of an organosilane gas by passing the exhaust gas through a packed layer of solid metal oxide, and a method for treating the same.

[0002]

2. Description of the Related Art Among the gases for manufacturing semiconductors, there are so-called metallic fluorine exhaust gases, particularly silicon tetrafluoride, silicon tetrachloride, and the like.
Metal fluorine exhaust gas such as germanium tetrafluoride, germanium tetrachloride, tungsten hexafluoride, etc., has attracted attention because of its unique performance as a doping gas.

[0003] However, most of these are treated as toxic gases, and are highly toxic, especially when they are strongly irritating to the respiratory tract by absorption, and if released in high concentrations to the outside, adverse effects on the human body and the natural environment are not likely to occur. Something is immeasurable. Therefore, reducing the concentration of metal fluorine gas in the exhaust gas in the manufacturing process and the semiconductor industry, to maintain a good working environment and to prevent the destruction of the natural environment,
It is a natural responsibility of the person who handles it.

Therefore, these metallic fluorine exhaust gases, like other toxic exhaust gases, need to be rendered harmless before being released to the atmosphere. Conventionally, wet treatment methods have been proposed. As a wet treatment, a treatment method of using a water washing scrubber and contacting with water is generally performed.

[0005]

However, these metal halogen gases are decomposed by water, and HF and H
Cl, metal oxides and the like are generated, and these secondary treatments are required. In addition, since silane, disilane, etc. are used after being doped, if a combustion type exhaust gas treatment device is treated with an exhaust gas containing a mixture of a metal halogen gas and monosilane, disilane, etc., the problem of damage to the equipment of the combustion treatment device is pointed out. There are many practical disadvantages.

[0006]

The inventors of the present invention have conducted intensive studies to obtain a treating agent capable of efficiently and safely treating a metal halogen exhaust gas and a method therefor.
It has been found that the object is achieved by using a solid metal oxide, and the present invention has been completed.

That is, the present invention provides a treatment agent for a metal halogen exhaust gas containing a solid metal oxide as a main component, or an exhaust gas containing a solid metal oxide as a main component and containing a metal halogen gas, passing through the solid metal oxide, The present invention relates to a method for treating a metal halogen exhaust gas, which is characterized by treating. [Detailed description of the invention]

Hereinafter, the present invention will be described in more detail. Most solid metal oxides can be used as the solid metal oxide used in the present invention. Among them, MgO, CaO, TiO ₂ ,
MnO ₂ , Fe ₂ O ₃ , CoO, NiO, CuO, ZnO
Are preferred because they are low in toxicity and easy to handle and relatively inexpensive. They can be used alone or as a mixture of two or more.

In the present invention, an exhaust gas containing a metal halogen exhaust gas is subjected to aeration treatment in a packed bed containing 10% by weight or more, preferably 50% by weight or more of the main component of the solid metal oxide. The specific surface area of the solid metal oxide used is 0.1 m ² /
g or more is desirable in order to improve the gas-solid contact ability with the metal halogen gas.

It is effective to feed the exhaust gas while heating the packed bed in order to enhance the exhaust gas treatment capacity of the solid metal oxide. However, the heating does not require any heating depending on the type of the solid metal oxide, and there are some which can sufficiently perform the exhaust gas treatment function even at room temperature. Depending on the processing rate, it is not essential. Therefore, in the present invention, the temperature of the solid metal oxide is preferably from 20 to 400C, more preferably from 20 to 250C. If the temperature exceeds 400 ° C., it is not preferable because the treating agent used is deteriorated and energy is lost.

At present, in a semiconductor factory, a metal halide gas remaining in a manufacturing process is diluted with a large amount of N ₂ gas and then transferred to a treatment process, so that the total amount of exhaust gas is considerable.

The filling layer may be filled with the powder as it is, but the solid metal oxide is desirably formed by granulation, tableting, or extrusion since the pressure loss increases and the gas flow becomes worse. At this time, the use of a binder necessary for granulation and the type thereof are not specified, and there is no problem in the present invention. As the binder used here, an organic binder such as methylcellulose, methylethylcellulose, and polyvinyl alcohol, and an inorganic binder such as water glass and bentonite can be used.

The packed column is made of a general-purpose material that can be used at high temperatures, such as iron, copper, stainless steel, nickel, or the like.
Alternatively, an oxide system such as glass or alumina, which is generally cylindrical, is used. The size of the packed column is determined according to the processing amount and processing capacity.

A single packed bed for practicing the present invention is sufficient, but from the viewpoint of operation such as regeneration and exchange, a plurality of packed layers are used in parallel, and each is switched to a processing layer and a regeneration layer. It is desirable to use. As described above, the gas-solid contact on the surface of the solid metal oxide can provide a treatment effect.

[0015]

The present invention will be described below in more detail with reference to examples. In addition,% and ppm represent a capacity standard. Example 1 CuO particles having a specific surface area of 58 m ² / g were molded in a 16.5 φmm × 200 mm stainless steel column with a tablet machine, and a filling amount of 20 cc was filled. Then, WF ₆ gas was diluted to 1% with helium gas, and 67 cc. The gas was passed through the packed bed at / min, and the WF ₆ gas concentration in the outlet gas of the packed bed was analyzed. The analysis was performed by a gas chromatograph (GC-3000 manufactured by Hitachi) equipped with a photoionization detector (PID). Porapak-P is used for the separation column. As shown in Table 1, a decrease in the WF ₆ gas concentration after 30 minutes of ventilation was confirmed.

Example 2 Using the same column and gas chromatograph as in Example 1, MgO particles having a specific surface area of 0.7 m ² / g were molded with a tablet machine, and the filling amount was 20 cc. After heating the packed layer portion to 200 ° C. with a heater, the WF ₆ gas was diluted to 1% with helium gas, passed through the packed layer at 67 cc / min, and the WF ₆ gas concentration in the packed layer outlet gas was analyzed. .
The analysis was performed by a gas chromatograph (GC-3000 manufactured by Hitachi) equipped with a photoionization detector (PID). Porapak-P is used for the separation column. As shown in Table 1, a decrease in the WF ₆ gas concentration after 30 minutes of ventilation was confirmed.

Examples 3 to 12 Using the same column and gas chromatography as in Example 1 except that the solid metal oxide, shape, metal halogen gas, packed bed temperature and gas concentration before aeration were changed as shown in Table 1. went. As a result, it was confirmed that the concentration of the metal halogen gas was reduced by using the metal oxides listed in Table 1.

Example 13 A column similar to that of Example 1 was filled with helium gas containing monosilane gas and WF ₆ gas at a concentration of 1%, respectively, and charged with 20 cc of CuO having a specific surface area of 58 m ² / g by a tablet machine. The column was vented. As a result, as shown in Table 1, it was confirmed that the concentration of both the monosilane gas and the WF ₆ gas was reduced.

[0019]

[Table 1]

[0020]

As described above in detail, according to the present invention, it is possible to efficiently and safely treat the exhaust gas by passing the metal halogen exhaust gas through the packed layer of the solid metal oxide. Further, the size of the apparatus can be reduced as compared with the conventional processing method.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 4D002 AA17 AA18 AA22 AA26 AC10 BA12 BA15 CA07 DA05 DA06 DA11 DA21 DA22 DA23 DA24 DA47 DA70 GA01 GA02 GB02 GB03 GB08 GB12 HA03 4G066 AA15B AA16B AA17B AA18B AA23B AA26B A32A FA27 FA37

Claims (8)

[Claims] An agent for treating a metal halogen exhaust gas containing a solid metal oxide as a main component. 2. The solid metal oxide element is Mg, C
The treating agent according to claim 1, wherein the treating agent is selected from a, Ti, Mn, Fe, Co, Ni, Cu, and Zn. 3. The treating agent according to claim 1, wherein the metal halogen exhaust gas is an exhaust gas containing a metal fluorine gas and / or a metal chlorine gas. 4. The treating agent according to claim 1, wherein the main component of the solid metal oxide is at least 10% by weight or more. 5. The solid metal oxide has a main component of 50% by weight.
The treating agent according to claim 1, which contains the above. 6. The solid metal oxide has a specific surface area of 0.1 m.
^2. The treating agent according to claim 1, wherein the treating agent is particles having a particle size of ² / g or more, which are formed by granulation or / and tableting and extrusion. 7. An exhaust gas containing a solid metal oxide as a main component and containing a metal halogen gas passes through the solid metal oxide,
A method for treating a metal halogen exhaust gas, which comprises treating the exhaust gas. 8. The treatment method according to claim 7, wherein the temperature at which the metal halogen exhaust gas passes through the solid metal oxide is 20 to 400 ° C.