Method and apparatus for purifying waste gas

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a method and a purification device for purifying exhaust gas discharged from a semiconductor manufacturing apparatus, and more particularly to a method and a purifying device for purifying exhaust gas discharged from a gallium nitride film semiconductor manufacturing apparatus using a large amount of ammonia. ..

【0002】

[Conventional technology]

Demand for gallium nitride film semiconductors, which are compound semiconductors, has been rapidly increasing in recent years mainly in the optical communication field as light emitting elements and light receiving elements. As a method for producing a gallium nitride film semiconductor, a MOCVD method in which an organic metal gas typified by trimethylgallium is used as a gallium source and vapor phase growth is formed by the reaction between the gallium gas and ammonia gas, and hydrogen chloride on metallic gallium The HVPE method (hydride VPE method) is well known, in which gallium chloride (GaCl) gas generated by flowing a gas is used as a gallium source and vapor phase is grown by the reaction between the gallium source and ammonia gas to form a film. All of these methods require a large amount of ammonia gas due to the low efficiency of nitrogen uptake from ammonia gas. In particular, the MOCVD method uses a large amount of ammonia gas, and a large amount of unreacted ammonia gas is discharged after the film formation process.

【0003】

In the HVPE method, gallium chloride (GaCl) is synthesized by the reaction of metallic gallium and hydrogen chloride at the first temperature, and the pre-set substrate is synthesized by the reaction of gallium chloride and ammonia at the second temperature. It grows a gallium nitride film on top. The reactor is a hot wall type and usually grows at normal pressure. Although the HVPE method uses less ammonia gas than the MOCVD method, it discharges a large amount of unreacted ammonia gas and at the same time a small amount of hydrogen chloride gas and a large amount of ammonium chloride powder. Since ammonia gas and hydrogen chloride gas are harmful gases, the exhaust gas containing these toxic gases emitted from the semiconductor manufacturing equipment needs to be purified before being released into the atmosphere.

【0004】

As a method for purifying ammonia gas in the field of the chemical industry, generally, a method using an aqueous solution of water or an acid as an absorption solution, or a wet absorption method using an aqueous solution such as a copper salt forming a complex salt with ammonia as an absorption solution has been used for a long time. It is well known and has been put to practical use. Similarly, as a method for purifying hydrogen chloride gas, a wet absorption method using an aqueous solution of water or an alkali as an absorption liquid has been known for a long time and has been put into practical use. In the field of the semiconductor manufacturing industry, if a wet absorption purification device is used as a primary purification device immediately after a normal pressure semiconductor manufacturing device, the product is adversely affected by the back diffusion of water from the absorption liquid to the semiconductor manufacturing device. As a result, such a method has hardly been put into practical use regardless of the type of exhaust gas to be purified.

【0005】

Therefore, in the field of the semiconductor manufacturing industry, the wet absorption method is put into practical use because the gas flow path is mechanically insulated by installing a vacuum pump or the like between the semiconductor manufacturing device and the purification device. This is the case of primary purification immediately after the decompression type semiconductor manufacturing apparatus so that the back diffusion of water from the absorbing liquid does not occur. In addition, the wet absorption method is used in the case of the final purification device in which the exhaust gas is collected immediately after the various semiconductor manufacturing devices and after the primary purification is completed by a purification method other than the wet absorption method. In the case of such an exhaust gas final purification device, since the exhaust gas from various semiconductor manufacturing devices is collected, the air volume is large, and a device that can be easily scaled up such as a wet absorption method is preferable.

【0006】

On the other hand, in the field of the semiconductor manufacturing industry, there are many semiconductor manufacturing devices that use ammonia gas. However, since the amount of ammonia gas used is relatively small except for the gallium nitride film semiconductor manufacturing apparatus, various methods can be used as the primary purification method. Examples of such a primary purification method include a dry adsorption method in which exhaust gas is introduced into a container filled with an adsorbent such as activated carbon and purified by a physical adsorption action, and an exhaust gas in a container filled with a chemical having a chemical reactivity with ammonia. There are dry reaction methods that purify by chemical reaction, and combustion methods that use hydrogen gas or propane gas as fuel to introduce the exhaust gas to be purified into the combustion flame and convert ammonia gas into nitrogen and water. Be done.

【0007】

Regarding the primary purification of the exhaust gas from the MOCVD method among the gallium nitride film semiconductor manufacturing equipment, the catalytic decomposition method in which the exhaust gas is introduced onto the catalyst under heating to decompose the ammonia gas into nitrogen gas and hydrogen gas, and the dry method described above. A method combining reaction methods is preferably used. Emissions from the MOCVD method include large amounts of ammonia gas and nitrogen gas, hydrogen gas and trace amounts of organometallic gases such as trimethylgallium. Of these, nitrogen gas and hydrogen gas do not need to be purified, and a trace amount of organometallic gas such as trimethylgallium can be purified by a known dry reaction method. Therefore, for the purpose of preventing the decomposition catalyst from being poisoned by the organometallic gas, the organometallic gas is first purified by a dry reaction method, and then the ammonia gas is decomposed into nitrogen gas and hydrogen gas on the heated catalyst. After that, a method of purifying a trace amount of ammonia gas that remains undecomposed by chemical equilibrium by a known dry reaction method is known.

【0008】

[Problems to be Solved by the Invention]

Of the gallium nitride film semiconductor manufacturing equipment, the exhaust gas from the HVPE method includes ammonia gas and nitrogen gas, hydrogen gas and a very small amount of hydrogen chloride gas, gallium chloride gas and a large amount of ammonium chloride, which are about 1/10 of the amount of the MOCVD method. Includes powder. Due to these characteristics, in order to respond to primary purification by a method that combines the above catalytic decomposition method and dry reaction method, the construction cost of the purification device is large for the small amount of ammonia gas processed. , It is not suitable because the installation space is large. In addition, hydrogen chloride gas, gallium chloride gas, and a large amount of ammonium chloride powder also cause poisoning of the decomposition catalyst, so it is necessary to purify them in advance upstream of the decomposition cylinder. For this reason, in general, a filter is first installed to remove ammonium chloride powder, and then a dry septic cylinder is used to purify hydrogen chloride gas and the like. In this case, since the ammonium chloride powder is a fine powder and a large amount, there is a problem that the treatment is difficult even if a filter or the like is used. If the filter is not installed, the dry septic cylinder may be blocked.

【0009】

In the case of the combustion type purification method, since the ammonium chloride powder may block the combustion nozzle, the powder must be treated in advance using a filter or the like, which is inconvenient. In this case, about half of the amount of ammonia to be treated becomes NOx, so there is a risk of environmental pollution. Further, in the wet absorption method, since the HVPE method uses a normal pressure semiconductor manufacturing apparatus, there is a concern that the back diffusion of water from the absorption liquid may adversely affect the product.

【0010】

For the above reasons, the dry method is currently adopted as the primary purification method in the HVPE method. The dry reaction method has excellent features such as high purification efficiency, complete removal of ammonia gas, easy handling, and a small installation space. Furthermore, there is an advantage that hydrogen chloride gas and gallium chloride gas can be removed at the same time by combining the chemicals to be filled.

【0011】

However, even in the dry reaction method, ammonium chloride powder is deposited between the chemicals and gradually increases the pressure loss, so that there is a problem that the powder becomes unusable due to the increase in the pressure loss before the full capacity of the chemicals is used up. In addition, there are problems that the running cost of the treatment is high because the chemicals of the dry reaction method are relatively expensive, and that a large amount of the chemicals after the treatment are generated as industrial waste.

【0012】

In view of the above points, an object of the present invention is to stably and efficiently treat the exhaust gas from the gallium nitride film semiconductor manufacturing apparatus, particularly from the HVPE method. Specifically, the installation space of the exhaust gas purification device is small, the construction cost is low, and the running cost of exhaust gas treatment does not adversely affect the product due to the back diffusion of water from the exhaust gas purification device to the semiconductor manufacturing device. It is to develop a purification method and a purification device for low exhaust gas. Another object of the present invention is that the exhaust gas purification device is easy to handle, gallium chloride gas can be completely removed at the same time as ammonia gas and hydrogen chloride gas, and the pressure loss does not increase due to the ammonium chloride powder. Furthermore, it is to provide an exhaust gas purification method and a purification device capable of reducing industrial waste without causing environmental pollution due to NOx or the like.

【0013】

[Means for solving problems]

As a result of diligent research on a method for solving these problems, the present inventors have found that the cross-sectional area and length of the pipe connecting the gallium nitride film semiconductor manufacturing apparatus and the wet absorption method exhaust gas purification apparatus and the gas in the pipe. By specifying the relationship between the flow rates, it was found that the increase in pressure loss due to the adhesion of ammonium chloride powder in the piping can be prevented, and the back diffusion of water from the absorption liquid of the purification device can be completely prevented. It was also found that by using hydrochloric acid or an aqueous solution of an acid having a weaker acidity than hydrochloric acid as the absorption liquid, it is possible to dissolve and remove a trace amount of gallium chloride powder and a large amount of ammonium chloride powder contained in the exhaust gas. It was. As a result, there is no trouble in the absorption liquid circulation system due to crystal precipitation in the piping connecting the semiconductor manufacturing equipment and the exhaust gas purification equipment, and a large amount of ammonia gas can be absorbed and treated, and further, from the absorption liquid. It was found that the amount of desorption of acid gas such as ammonia gas and hydrogen chloride gas can be suppressed to an extremely low level.

【0014】

Furthermore, in order to remove acid gases such as ammonia gas and hydrogen chloride gas that are slightly desorbed from the absorption liquid, a wet absorption method exhaust gas purification device that uses water as the absorption liquid is installed after the purification device, or with a mist separator. The present invention has been completed by finding that complete purification can be achieved by additionally introducing a dry gas as needed to prevent water condensation and then providing a known dry purification device.

【0015】

That is, the present invention is from an apparatus for manufacturing a gallium nitride film semiconductor, which uses gallium chloride (GaCl) gas generated by flowing hydrogen chloride gas through metallic gallium as a gallium source and causes vapor phase growth by reacting the gas with ammonia to form a film. In the wet absorption method exhaust gas purification method for treating the exhaust gas of the above, the relationship between the pipe connecting the manufacturing device and the wet absorption method exhaust gas purification device and the exhaust gas flow rate in the pipe is determined by the cross-sectional area (cm) of the pipe.²) With exhaust gas flow rate (cm)³This is an exhaust gas purification method characterized in that the product of the value obtained by dividing (/ sec) and the length (cm) of the pipe is set to be in the range of 100 to 25,000.

【0016】

Further, the present invention is from a gallium nitride film semiconductor manufacturing apparatus that uses gallium chloride (GaCl) gas generated by flowing hydrogen chloride gas through metallic gallium as a gallium source and causes vapor phase growth by reacting the gas with ammonia to form a film. In a wet absorption method exhaust gas purification device for purifying exhaust gas, the wet absorption method exhaust gas purification device is a pipe connecting the wet absorption method exhaust gas purification device and the gallium nitride film semiconductor manufacturing device, and its cross-sectional area (cm).²) Is the exhaust gas flow rate (cm) in the pipe.³It is an exhaust gas purification device characterized by having a pipe in which the product of the value obtained by dividing (/ sec) and the length (cm) of the pipe is in the range of 100 to 25,000.

【0017】

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention is applied to a method and a purification device for purifying exhaust gas from a semiconductor manufacturing device. More specifically, it is applied to a method and a purification device for purifying an exhaust gas containing a large amount of ammonia gas discharged from a gallium nitride film semiconductor manufacturing apparatus.

【0018】

The present invention relates to a pipe connecting a gallium nitride film semiconductor manufacturing apparatus by the HVPE method or the like and a wet absorption exhaust gas purification apparatus and the gas flow rate thereof, and has a cross-sectional area (cm) of the pipe.²) With gas flow rate (cm)³The product of the value divided by (/ sec) and the length (cm) of the pipe is in the range of 100 to 25000, preferably 200 to 5000, and more preferably 500 to 2000. Here, the pipe diameter is determined according to the gas flow rate, and the equivalent diameter (cm) when the cross-sectional shape is regarded as a circle is usually 1 to 20 cm, preferably 2 to 15 cm, and more preferably 3 to. It is 10 cm. The length of the pipe is appropriately determined depending on the installation position of the reactor of the semiconductor manufacturing equipment and the purification equipment, but the cross-sectional area of the pipe (cm).²) With gas flow rate (cm)³It is set considering that the product of the value excluding (/ sec) and the length (cm) of the pipe is in the range of 100 to 25000.

【0019】

Here, if the gas flow rate is too small to satisfy the above range of 100 to 25000, nitrogen gas or the like can be additionally introduced to optimize the conditions. Cross-sectional area of piping (cm²) With gas flow rate (cm)³If the product of the value excluding (/ sec) and the length of the pipe (cm) is less than 100, there is an inconvenience that back diffusion of water occurs, and if it is larger than 25000, the pressure loss becomes large. There is. If the equivalent diameter of the pipe is smaller than 1 cm, clogging in the pipe due to the adhesion of ammonium chloride powder may cause an increase in pressure loss, which is not preferable. If the equivalent diameter is larger than 20 cm, the gas flow will flow. It is not preferable because it may become unstable and cause back diffusion of water.

【0020】

In the present invention, as the type of acid used in the ammonia absorption liquid in the wet absorption method exhaust gas purification device, hydrochloric acid or an acid having a weaker acidity than hydrochloric acid, for example, phosphoric acid or acetic acid can be used. Of these, it is preferable to use an aqueous solution of hydrochloric acid from the viewpoints of price, solubility of salts, treatment of the absorbing liquid after purification of exhaust gas, and the like. There are no particular restrictions on the concentration of acid in the absorption liquid, but the higher the concentration, the greater the absorption capacity of ammonia gas, which is advantageous.

【0021】

However, in the ammonia gas absorption liquid, in addition to the ammonium salt produced by the absorption of the ammonia gas, the amount of ammonium chloride powder flowing in from the semiconductor manufacturing equipment increases with the passage of time, and the ammonium chloride and the ammonium salt are eventually dissolved. The limit will be exceeded. As a result, troubles such as clogging due to crystal precipitation occur. Therefore, the concentration of the acid used in the absorbing liquid is usually preferably 15% by weight or less. When an acid with a stronger acidity than hydrochloric acid is used as the absorption liquid, the ammonium chloride powder into which the strong acid flows may be decomposed to generate hydrogen chloride gas, which increases the burden on the dry purification device in the subsequent stage. I have something to do.

【0022】

In the present invention, a wet absorption method exhaust gas purification device using water as an absorption liquid is further provided after the wet absorption method purification device, or a dry gas is additionally introduced by a mist separator and if necessary. By introducing the system into a known dry purification device after preventing water condensation, the exhaust gas from the gallium nitride film semiconductor manufacturing device can be stably and efficiently purified.

【0023】

This method is used for purifying exhaust gas from HVPE furnaces, and is also applicable to purifying exhaust gas from small MOCVD furnaces that consume a large amount of ammonia gas, although it is not a mass production furnace. In that case, it is preferable to install a purification device by a dry reaction method or a dry adsorption method in front of the wet absorption method purification device in order to remove organic metals and the like.

【0024】

[Example]

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. (Example 1) (Semiconductor manufacturing equipment and exhaust gas purification equipment) We manufactured a gallium nitride film semiconductor manufacturing equipment and a wet absorption method purification equipment using an HVPE furnace as shown in Fig. 1. As an HVPE furnace, it has a supply pipe 3 for a mixed gas of ammonia and hydrogen, a supply pipe 3'for hydrogen chloride and hydrogen, an exhaust gas outlet 4, a boat 5 containing metallic gallium, and a substrate 6 placed on a susceptor 7. Then, a quartz reactor 1 equipped with a heater 2 was used. However, the mist separator 17 and the dry septic cylinder 21 in the latter stage were not installed and nitrogen gas was not supplied.

【0025】

In the wet absorption method purification device 9, four layers of laminated filters 14 (manufactured by Asahi Kasei Co., Ltd., Saran Rock Filter) with a thickness of 50 mm are stacked on the absorption cylinder 10 of a square square cylinder with a side length of 140 mm on the inside. It is filled and has a structure in which an absorption liquid 12 composed of an aqueous solution of hydrogen chloride is sprayed and absorbed from the upper part of a laminated filter from a spray nozzle 11 via a circulation pump 13. Further, the exhaust gas outlet 4 and the wet absorption method purification device 9 were connected by a stainless steel pipe 8 having an inner diameter of 4.53 cm and a length of 150 cm.

【0026】

(Exhaust gas purification test) GaN was grown on the sapphire substrate as follows. In the HVPE furnace shown in Fig. 1, the boat 5 containing Ga metal is always kept at 800 ° C or more and 1000 ° C or less, and the vicinity of the set position of the sapphire substrate 6 is 400 to 600 when the low temperature buffer layer grows. It was kept at ° C and kept at 800 to 1100 ° C during subsequent epitaxial growth.

【0027】

The growth procedure was as follows. After setting the sapphire substrate 6 in the reactor, it was cleaned at 1050 ° C in a hydrogen atmosphere. Next, sapphire substrate at 550 ° C, hydrogen chloride gas at a flow rate of 5 sccm (standard cubic centimeter per minute), and ammonia at a flow rate of 0.5 slm (standard liter per minute), with hydrogen carriers from supply pipes 3'and 3, respectively. A low temperature buffer layer was grown by running at a total flow rate of about 5 slm for about 20 minutes. After that, the temperature around the sapphire substrate 6 is raised to a growth temperature of 1020 ° C, and hydrogen chloride gas is flowed on the sapphire substrate at a flow rate of 10 sccm, and ammonia gas is flowed together with a hydrogen carrier at a flow rate of 1 slm at a total flow rate of 5 slm for about 20 minutes. A GaN epitaxial growth layer having a thickness of about 10 μm was obtained. Such a growth operation was repeated 5 times. During this period, the wet absorption purification apparatus 9 purified the exhaust gas from the HVPE furnace by circulating a 2.3 mol / l hydrogen chloride aqueous solution at a flow rate of 6 L / m (liter per minute) at room temperature.

【0028】

As a result, no clogging or the like was observed in the piping between the exhaust gas outlet and the wet absorption method purification device, and smooth growth work was performed. In addition, the pressure difference between the reactor and the outlet of the wet absorption purification device is always 4 mmH.₂It was O, and no increase in pressure loss was observed. When the exhaust gas discharged from the wet absorption method purification device was analyzed with an ammonia detector tube (Gastec Co., Ltd., 3La type, detection sensitivity 2.5 to 250 ppm), the ammonia content was below the detection limit. Similarly, when the concentration of hydrogen chloride in the exhaust gas was measured with a detector tube (Gastec Co., Ltd., 14L type, detection sensitivity 1 to 20ppm), it was 3ppm or less.

【0029】

Cross-sectional area of the pipe in this case (cm²) With exhaust gas flow rate (cm)³The product of the value divided by (/ sec) and the length (cm) of the pipe was 776, which was in the range of 100 to 25000. In addition, the characteristics of the grown GaN epitaxial layer were evaluated in order to investigate the effect of the back diffusion of water vapor from the wet absorption purification device into the reaction furnace on the grown GaN epitaxial layer. As a result, regarding the electrical characteristics, the carrier concentration is 2.0E17 / cm.², Carrier mobility 420cm²It was / Vs. In addition, when photoluminescence was measured, strong band-end emission was observed at 357 nm at 4.2K, and no emission in the long wavelength region was observed, showing good characteristics.

【0030】

(Example 2) In Example 1, the piping connecting the reactor and the wet absorption purification device is changed to an inner diameter of 7.31 cm and a length of 150 cm, and zinc oxide is the main component after the wet absorption purification device. The epitaxial growth of gallium nitride was repeated 5 times in the same manner as in Example 1 except that a dry septic cylinder filled with a dry purifying agent was provided and dry nitrogen gas was introduced at 2 slm immediately before the dry septic cylinder.

【0031】

During this period, no particular clogging of ammonium chloride was observed. In addition, the pressure difference between the reactor and the outlet of the dry septic cylinder is always 9 mmH.₂It was O, and there was no sign of increased pressure loss in the entire purification system. In addition, ammonia was not detected in the exhaust gas from the outlet of the dry septic cylinder. In addition, no hydrogen chloride was detected.

【0032】

Cross-sectional area of the pipe in this case (cm²) With exhaust gas flow rate (cm)³The product of the value divided by (/ sec) and the length (cm) of the pipe is 298, which is in the range of 100 to 25000. When the electrical characteristics of the GaN epitaxial layer grown in this experiment were evaluated, they showed the same excellent characteristics as those obtained in Example 1.

【0033】

(Example 3) In the same manner as in Example 2, the epitaxial growth of gallium nitride was carried out in the same manner as in Example 2, except that the piping connecting the reactor and the wet absorption method purification device in Example 2 was changed to an inner diameter of 3.1 cm and a length of 150 cm. Repeated 5 times.

【0034】

During this period, no clogging of ammonium chloride was observed. In addition, the pressure difference between the reactor and the outlet of the dry septic cylinder is always 9 mmH.₂It was O, and there was no sign of increased pressure loss in the entire purification system. In addition, neither ammonia nor hydrogen chloride was detected in the exhaust gas from the outlet of the dry septic cylinder. Cross-sectional area of the pipe in this case (cm²) With exhaust gas flow rate (cm)³The product of the value divided by (/ sec) and the length (cm) of the pipe is 1657, which is in the range of 100 to 25000. When the electrical characteristics of the GaN epitaxial layer grown in this experiment were measured, they showed the same excellent characteristics as those obtained in Example 1.

【0035】

(Example 4) In the same manner as in Example 2, the epitaxial growth of gallium nitride was carried out in the same manner as in Example 2 except that the piping connecting the reactor and the wet absorption purification apparatus in Example 2 was changed to an inner diameter of 1.14 cm and a length of 150 cm. Repeated 5 times.

【0036】

During this period, no clogging of ammonium chloride was observed. In addition, the pressure difference between the reactor and the outlet of the dry septic cylinder is always 10 mmH.₂It was O, and there was no sign of increased pressure loss in the entire purification system. In addition, neither ammonia nor hydrogen chloride was detected in the exhaust gas from the outlet of the dry septic cylinder. Cross-sectional area of the pipe in this case (cm²) With exhaust gas flow rate (cm)³The product of the value divided by (/ sec) and the length (cm) of the pipe is 12240, which is in the range of 100 to 25000. The electrical characteristics of the GaN epitaxial layer grown in this experiment were measured. As a result, it showed the same excellent characteristics as those obtained in Example 1.

【0037】

(Comparative Example 1) Except that the piping connecting the reactor and the wet absorption purification device in Example 2 was changed to an inner diameter of 14.96 cm and a length of 100 cm, gallium nitride was epitaxially grown 5 times under the same conditions as in Example 2. Repeated.

【0038】

During this time, the pressure difference between the reactor and the outlet of the dry septic cylinder is 9 mmH.₂It was constant at O. In this case, the cross-sectional area of the pipe (cm)²) With exhaust gas flow rate (cm)³The product of the value obtained by dividing (/ sec) and the length (cm) of the pipe is 47, which is outside the scope of the present invention. The characteristics of the GaN epitaxial layer grown in this experiment were evaluated. As a result, regarding the electrical characteristics, the carrier concentration is 5E19 / cm.², Carrier mobility 75 cm²It was / Vs. In addition, when photoluminescence was measured, band-end emission was observed at 357 nm at 4.2K, and emission in the long wavelength region was mixed.

【0039】

(Comparative Example 2) Gallium nitride was grown in the same manner as in Example 2 except that the piping in Example 2 was changed to an inner diameter of 0.6 cm and a length of 100 cm. In this case, the cross-sectional area of the pipe (cm)²) With exhaust gas flow rate (cm)³The product of the value obtained by dividing (/ sec) and the length (cm) of the pipe is 29488, which is outside the scope of the present invention. The pressure difference between the reactor and the outlet of the dry septic cylinder is initially 19 mmH.₂It was O, but the pressure difference gradually increased during vapor phase growth, and 256 mmH.₂Reached O. Therefore, when the pipe was removed and inspected, it was found that a large amount of ammonium chloride was attached to the pipe.

【0040】

[Effect of the invention]

According to the exhaust gas purification method and purification device according to the present invention, gallium nitride can be epitaxially grown without deteriorating the semiconductor characteristics due to the back diffusion of water. Further, according to the exhaust gas purification method and the purification device according to the present invention, the exhaust gas flow path does not have a cramped structure in which the gas flow is easily obstructed unlike the purification device by the dry adsorption method. It has become possible to repeatedly carry out epitaxial growth of gallium nitride without causing clogging of ammonium chloride.

[Simple explanation of drawings]

[Figure 1]

Schematic process diagram showing an example of a semiconductor manufacturing apparatus and an exhaust gas purification apparatus of the present invention [Explanation of symbols]

1 Reactor 2 heater 3 Ammonia and hydrogen mixed gas supply piping 3'Hydrogen chloride and hydrogen mixed gas supply piping 4 Exhaust gas outlet 5 metal gallium boat 6 board 7 susceptor 8 plumbing 9 Wet absorption method purification device 10 Absorbent cylinder 11 spray nozzle 12 Absorbent 13 pump 14 Laminated filter 15 Absorbent liquid circulation piping 16 Absorption cylinder outlet piping 17 Mist separator 18 Mist separator return piping 19 Nitrogen supply piping 20 Dry septic cylinder entrance piping 21 Dry septic cylinder 22 Dry purifier 23 Exhaust gas purge line