JP2011041894A - Method for treating exhaust gas and detoxifying agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for treating exhaust gas, in which hydrazine derivatives included in the exhaust gas to be discharged from a semiconductor manufacturing process can be effectively detoxified and to provide a detoxifying agent. <P>SOLUTION: The exhaust gas including hydrazine or hydrazine derivatives is brought into contact with the detoxifying agent including ferric oxide as a main reactive component. Particularly, the exhaust gas including at least one of an organometallic compound, an amine compound and volatile inorganic hydride is brought into contact with the detoxifying agent first to detoxify the hydrazine or hydrazine derivatives. Then, the organometallic compound, the amine compound and volatile inorganic hydride included in the exhaust gas are surely detoxified. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an exhaust gas treatment method and an abatement agent for detoxifying hydrazine and hydrazine derivatives (hereinafter referred to as hydrazine derivatives including hydrazine) contained in exhaust gas discharged from a semiconductor manufacturing process.

  In recent years, in the field of III-V compound semiconductors, a method of adding a hydrazine derivative or an amine compound has been adopted with the aim of lowering the film forming temperature and improving the film forming speed.

  Further, when a layer containing indium used for light emitting elements such as LEDs and lasers emitting light in the region from blue to green is vapor-phase grown, the growth temperature is from a normal temperature of about 1000 ° C. to a relatively low temperature of 700 to It is necessary to set the temperature to 800 ° C. When forming a light-emitting element having a double heterostructure, for example, after forming an n-type cladding layer at about 1000 ° C., an indium-containing layer is formed at about 700 ° C. to form a p-type cladding layer. It is necessary to perform the film again at around 1000 ° C. However, since the bond between indium and nitrogen is relatively weak to heat, there is a problem in that the layer containing indium deteriorates during the formation of the p-type cladding layer and the luminous efficiency decreases. In particular, for a compound semiconductor that uses nitrogen as a group V element, ammonia is usually used as a film forming gas. For example, in order to suppress the deterioration of the indium layer, when the p-type cladding layer is formed at a low temperature of 700 to 800 ° C. similar to the indium-containing layer, the decomposition efficiency of ammonia is remarkably lowered, and the crystallinity of the p-type cladding layer is reduced. There was a problem of getting worse.

  In order to solve this, as a method for growing a group III-V compound semiconductor at a low temperature, a method using dimethylhydrazine as another organic nitrogen source having a high decomposition efficiency at a low temperature (for example, see Patent Document 1). A method using ammonia and hydrazine (for example, refer to Patent Document 2), a method using an amine compound (for example, refer to Patent Document 3), and the like are disclosed.

  In addition, when an amine compound is decomposed at a high temperature, a hydrazine derivative is formed, and this point must be taken into consideration in the exhaust gas treatment. When a hydrazine derivative or an amine compound is used as the nitrogen source in the film, it is possible to use the hydrazine derivative, the amine compound and ammonia at the same time. For example, if necessary, ammonia, a hydrazine derivative and an amine compound are used on the apparatus side. It is also possible to switch and use.

  However, in the above-mentioned system detoxification treatment, it is necessary to treat ammonia and hydrazine derivatives, amine compounds and organometallic compounds, and volatile inorganic hydrides. However, ammonia and amine compounds are removed by a heated catalytic decomposition apparatus. It can be harmful. However, the hydrazine derivative could not be removed, and a special detoxifying agent was required. Moreover, since this abatement agent also reacts with ammonia, the abatement agent is rapidly consumed in the presence of a large amount of ammonia, the abatement agent is deactivated, and the abatement of the hydrazine derivative becomes impossible. There was a problem.

  Furthermore, since the hydrazine derivative also reacts with an organometallic compound and a detoxifying agent for volatile inorganic hydrides, the detoxifying agent is consumed rapidly in a system in which a large amount of the hydrazine derivative is used. There is a problem that the deactivation of the organometallic compound and the volatile inorganic hydride is impossible due to deactivation.

  In order to solve this, it is disclosed that the exhaust system is separated using a switching valve at the rear stage of the apparatus, and the solution is achieved by switching the detoxification of ammonia and the hydrazine derivative according to the gas used in the apparatus (for example, (See Patent Document 4).

JP 2001-144325 A JP-A-9-251957 JP 2003-37288 A Japanese Patent No. 4196767

  However, in the above-mentioned Patent Document 4, in a system in which ammonia and a hydrazine derivative are mixed and used, or in a system in which an amine compound is used and a hydrazine derivative is generated as a by-product after the reaction, the treatment is performed. It was impossible.

  Accordingly, an object of the present invention is to provide an exhaust gas treatment method and a detoxifying agent that can effectively remove an hydrazine derivative contained in an exhaust gas discharged from a semiconductor manufacturing process.

  In order to achieve the above object, the exhaust gas treatment method of the present invention is characterized in that exhaust gas containing hydrazine or a hydrazine derivative is brought into contact with a detoxifying agent containing iron (III) oxide as a main reaction component. In particular, when performing a detoxification treatment of exhaust gas containing at least one of an organometallic compound, an amine compound, and a volatile inorganic hydride, the exhaust gas is first contacted with the abatement agent to obtain hydrazine or a hydrazine derivative. After the detoxification treatment, the detoxification treatment of the organometallic compound, amine compound and volatile inorganic hydride contained in the exhaust gas is performed.

  Further, the detoxifying agent of the present invention is a detoxifying agent for treating hydrazine and hydrazine derivatives contained in exhaust gas, and is characterized by containing iron (III) oxide as a main reaction component.

In the present invention, a hydrazine derivative includes an NN bond in a molecule, and R ¹ R ² N—NR ³ R ⁴ (R ¹ , R ² , R ³ , R ⁴ is H or an organic side in the general formula. A chain.). Specifically, hydrazine, methyl hydrazine, 1,1 dimethyl hydrazine, 1,2 dimethyl hydrazine, ethyl hydrazine, 1,1 diethyl hydrazine, 1,2 diethyl hydrazine, 1 methyl 1 ethyl hydrazine, 1 methyl 2 ethyl hydrazine, phenyl Examples thereof include hydrazine, 1,1-diphenylhydrazine, 1,2-diphenylhydrazine, 1-methyl-1-phenylhydrazine, 1-methyl-2-phenylhydrazine, 1-ethyl-1-phenylhydrazine, and 1-ethyl-2-phenylhydrazine.

The amine compound includes nitrogen in the molecule, and is a compound excluding ammonia represented by NR ¹ R ² R ³ (R ¹ , R ² , R ³ are H or an organic side chain) in the general formula. It is. Specifically, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, arylamine, diarylamine, triarylamine, isobutylamine, diisobutylamine, triisobutylamine, normal propylamine, dinormal propylamine, trinormal Mention may be made of propylamine, phenylamine, diphenylamine, triphenylamine.

  Furthermore, specific examples of the volatile inorganic hydride include ammonia, arsine, phosphine, silane, disilane, hydrogen selenide, monogermane, and diborane. Specific examples of the organometallic compound include May include trimethylaluminum, triethylaluminum, tetramethylgallium, tetraethylgallium, triethylindium, dimethylzinc, diethylzinc, and cyclopentadienylmagnesium.

  According to the exhaust gas treatment method of the present invention, an exhaust gas containing a hydrazine derivative (including hydrazine) is brought into contact with a detoxifying agent containing iron (III) oxide as a main reaction component, thereby detoxifying the hydrazine derivative. Can do.

  Also, in the case of exhaust gas containing hydrazine derivatives, organometallic compounds, amine compounds, and volatile inorganic hydrides, it is brought into contact with a detoxifying agent containing iron (III) oxide as a main reaction component in the first stage of detoxification treatment. By detoxifying the hydrazine derivative, the detoxifying agent for detoxifying the organometallic compound, amine compound and volatile inorganic hydride in the subsequent stage is not consumed by the hydrazine derivative. In addition, the amine compound and the volatile inorganic hydride can be reliably detoxified.

The detoxifying agent used in the exhaust gas treatment method of the present invention contains iron (III) oxide (Fe ₂ O ₃ ) (ferric oxide) as a main reaction component. Various iron oxides exist, but iron oxide (II, III) (Fe ₃ O ₄ ) does not react with hydrazine derivatives, and iron oxide (II) (FeO) is other than hydrazine derivatives such as ammonia. As a detoxifying agent for detoxifying the hydrazine derivative, iron (III) oxide that can selectively detoxify the hydrazine derivative is used as a main reaction component.

  The detoxifying agent is preferably shaped into a spherical shape, a cylindrical shape, a cylindrical shape, a crushed shape, etc., and shaped into a granule having a maximum length in the range of 1 to 20 mm and a shortest length in the range of 1 to 20 mm. . As a molding method of the pesticide, general molding methods such as extrusion granulation, rolling granulation, tableting and crushing can be adopted, but pressure is not easily applied during granulation, and gas diffuses inside. The rolling granulation method, which can be molded into an easy state, is optimal. In molding, a small amount of water or solvent may be added as necessary.

Such a granular form of the detoxifying agent is usually used for the detoxification treatment of exhaust gas in a state where the detoxifying column is packed. The packing density of the detoxifying agent in the detoxifying column varies depending on the shape of the detoxifying agent and the molding method, but it is generally desirable that the density be in the range of 0.5 to 1.0 g / cm ³ . When the packing density is less than 0.5 g / cm ³ , the strength of the molded product is weakened, and the throughput per unit volume is reduced. When the packing density is greater than 1.0 g / cm ³ , the differential pressure increases. For this reason, the detoxification efficiency may be reduced.

  This detoxifying agent mainly composed of iron (III) oxide is used by detoxifying exhaust gas discharged from the semiconductor manufacturing process before detoxifying other components to be detoxified. In addition, it is possible to efficiently perform the detoxification process for other detoxification target components in the subsequent stage.

  For example, in the case of detoxifying exhaust gas containing at least one of volatile inorganic hydrides such as ammonia, organometallic compounds, and amine compounds as other detoxifying components, including hydrazine derivatives, In the first stage, exhaust gas is brought into contact with the detoxifying agent containing iron (III) oxide as a main component of the reaction, and the hydrazine derivative in the exhaust gas is selectively detoxified in advance. It is possible to reliably perform the detoxification treatment of the detoxification target component without being affected by the hydrazine derivative.

  In addition, when the detoxification treatment of other detoxification target components is performed with a detoxifying agent corresponding to the other detoxification target component, the iron (III) oxide is added to the upstream side of one detoxification column. Detoxification treatment of hydrazine derivatives in one detoxification column and other detoxification targets by filling the detoxification agent as the component and filling the detoxification agent corresponding to other detoxification target components on the downstream side Component detoxification treatment can be performed, and the equipment cost can be reduced.

Iron oxide (II) base, iron oxide (III) base, iron oxide (II, III) base, zinc oxide (ZnO) base, titanium oxide (TiO ₂ ) base, alumina (Al ₂ O ₃ ) base, copper oxide ( Each detoxifying agent based on (CuO) -zinc oxide (ZnO) was processed into an extruded product of 3 mmφ × 5 mm. Each detoxifying agent was packed to a height of 100 mm in a column with an inner diameter of 50 mm into which thermocouples were inserted at intervals of 50 mm. The filling amount of each detoxifying agent was in the range of 100 to 130 g.

Each column filled with each detoxifying agent contains ammonia (NH ₃ ), 1,1-dimethylhydrazine (DMHy), trimethylgallium (TMG), and arsine (AsH ₃ ) in a volume of 1% by volume in nitrogen gas. The sample gas was circulated at a flow rate of 1 liter per minute, and the time until breakthrough was measured. In addition, the determination of breakthrough is that ammonia is a constant potential electrolytic detector for ammonia (TG-2400 made by bionics equipment), arsine is a constant potential electrolytic detector for arsine (TG-4000 made by bionics equipment), For 1,1-dimethylhydrazine and trimethylgallium, FT-IR (manufactured by Horiba: FT-730G) was used. The results are shown in Table 1 (the unit is time. The same applies hereinafter).

Iron oxide (III) -based and zinc oxide-based detoxifying agents with relatively high DMHy / NH ₃ capacity ratios, and alumina and iron (II) oxide-based detoxifying agents with high ammonia and dimethylhydrazine treatment capabilities The column was packed in the same manner as above. A sample gas containing 10% by volume of ammonia in nitrogen gas is flowed through each column at a flow rate of 1 liter per minute until the scavenger heat generated by the thermocouple inserted into the column disappears and all returns to room temperature. Thereafter, a sample gas containing 1% by volume of 1,1-dimethylhydrazine in nitrogen gas was passed through each column at a flow rate of 1 liter per minute, and the time until breakthrough was measured. The results are shown in Table 2.

Four types containing 1% by volume each of hydrazine (Hy), monomethylhydrazine (MMHy), and phenylhydrazine (PhHy) in nitrogen gas in a column in which the column is filled with an iron (III) oxide-based detoxifying agent as described above. The sample gas was circulated at a flow rate of 1 liter per minute, and the time until breakthrough was measured. The results are shown in Table 3.

  From these results, as shown in Table 1, iron oxide (II) and alumina show a high detoxification ability for sample gases containing only ammonia and 1,1-dimethylhydrazine, respectively. As is clear from the results, when ammonia and 1,1-dimethylhydrazine coexist, the reaction with ammonia proceeds and deactivates, and the ability to remove 1,1-dimethylhydrazine is reduced. I understand. On the other hand, iron (III) oxide can be removed by reacting with 1,1-dimethylhydrazine even after contacting with ammonia.

  Therefore, when hydrazine derivatives, ammonia, organometallic compounds, and volatile inorganic hydrides are mixed in the exhaust gas discharged from the semiconductor manufacturing process, the exhaust gas is used as a detoxifying agent mainly composed of iron (III) oxide. It can be seen that only the hydrazine derivative can be selectively detoxified from the exhaust gas.

An iron (III) -based detoxifying agent is 900 mm high on the upstream side in the gas flow direction of a column with an inner diameter of 50 mm, and a copper hydroxide (Cu (OH) ₂ ) -based detoxifying agent is 100 mm high on the downstream side. The layers were stacked and filled. After flowing a mixed gas of nitrogen and ammonia into this column, the exothermic reaction was completed and the temperature of the harmful agent was stabilized. Then, 1-1,1-dimethylhydrazine 1%, trimethylgallium 500 ppm, methyl A sample gas containing 1% amine and 10% ammonia was circulated at a flow rate of 1 liter per minute, and the breakthrough time was measured (Example).

In addition, a column packed with the copper hydroxide-based detoxifying agent on the upstream side in the gas flow direction and the iron (III) oxide-based detoxifying agent on the downstream side is used, and breakthrough is performed under the same conditions. Time was measured (comparative example). The results are shown in Table 4.

  In the comparative example, it can be seen that the removal efficiency of trimethylgallium is reduced by the reaction between the copper hydroxide-based harmful agent and 1,1-dimethylhydrazine. Therefore, when exhaust gas that contains hydrazine derivatives, ammonia, organometallic compounds, and volatile inorganic hydrides is to be detoxified, the exhaust gas is first contacted with an abatement agent whose main component is iron (III) oxide. The hydrazine derivative is selectively detoxified, and the detoxification treatment of ammonia, organometallic compounds, and volatile inorganic hydrides is performed effectively based on the subsequent copper hydroxide base. I understand that I can do it.

Claims (3)

An exhaust gas treatment method comprising contacting exhaust gas containing hydrazine or a hydrazine derivative with a detoxifying agent containing iron (III) oxide as a main component of reaction. The exhaust gas contains at least one of an organometallic compound, an amine compound, and a volatile inorganic hydride, and after the exhaust gas is first contacted with the detoxifying agent to detoxify hydrazine or a hydrazine derivative, the exhaust gas The exhaust gas treatment method according to claim 1, wherein a detoxification treatment of the organometallic compound, the amine compound, and the volatile inorganic hydride contained in the catalyst is performed. A detoxifying agent for detoxifying hydrazine and hydrazine derivatives contained in exhaust gas, characterized by comprising iron (III) oxide as a main reaction component.