JP2009154091A - Exhaust gas treatment apparatus, exhaust gas treating method, and thin film forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To sufficiently detoxify two or more kinds of exhaust gases. <P>SOLUTION: An exhaust gas treatment apparatus (gas treatment apparatus) 108 is provided with a first gas treatment part 114 treating exhaust gas mainly containing a first exhaust gas, and a second gas treatment part 115 treating exhaust gas mainly containing a second exhaust gas. A first gas detoxifying part 116 is disposed upstream of the exhaust gas flow-in direction with respect to a second gas detoxifying part 117, in the first gas treatment part 114, and in the second gas treatment part 115, a second gas detoxifying part 118 is disposed upstream of the exhaust gas flow-in direction with respect to a first gas detoxifying part 119. Thus, even when both of the first and second exhaust gases are contained in the exhaust gas, the exhaust gas can be sufficiently detoxified. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an exhaust gas treatment apparatus, an exhaust gas treatment method, and a thin film forming apparatus, and more specifically, treats exhaust gas generated when a thin film is formed on a substrate using a plurality of material gases. The present invention relates to an exhaust gas treatment device, an exhaust gas treatment method, and a thin film forming apparatus including the exhaust gas treatment device.

As a method for manufacturing a light emitting layer of a semiconductor light emitting device such as an LED or a semiconductor laser, an organic metal gas such as trimethylgallium (TMG) or trimethylaluminum (TMA), ammonia (NH ₃ ), phosphine (PH ₃ ), allicin ( An MOCVD method (Metal Organic Chemical Vapor Deposition) in which a compound semiconductor thin film is formed using a material gas containing a hydrogen compound such as AsH ₃ ) is known. The MOCVD method is a method of forming a thin film on a substrate by introducing a material gas into a reaction furnace and heating it to cause a gas phase chemical reaction on the substrate.

  In such an MOCVD apparatus for forming a thin film by the MOCVD method, when exhausting the residual gas remaining in the apparatus, an exhaust gas processing system for detoxifying the harmful residual gas is required. A general MOCVD apparatus includes a reaction furnace for reacting a material gas, a material gas source for supplying the material gas to the reaction furnace, and an exhaust gas treatment apparatus for detoxifying the gas discharged from the reaction furnace.

  The configuration of a conventional MOCVD apparatus will be described below with reference to FIG. FIG. 3 is a schematic diagram showing the configuration of a conventional MOCVD apparatus 300. As shown in FIG. 3, a conventional MOCVD apparatus 300 includes a reaction furnace 301, a first gas supply unit 302, a second gas supply unit 303, a first flow rate control unit 304, a second flow rate control unit 305, A supply pipe 306, an exhaust gas transport pipe 307, an exhaust gas processing unit 308, and an exhaust pipe 309 are provided. The reaction furnace 301 includes a susceptor 311 and a heater 312. At the center of the susceptor 311, a counterbore with a large outer periphery of the substrate 310 is provided to support the back side of the substrate 310, and the substrate 310 is placed in the counterbore. The heater 312 heats the substrate 310 via the susceptor 311.

  A first gas supply unit 302 and a second gas supply unit 303, and a first flow rate control unit 304 and a second flow rate control unit 305 are connected to the reaction furnace 301 through a supply pipe 306. The flow rate of the material gas supplied from the first gas supply unit 302 to the reaction furnace 301 is controlled by the first flow rate control unit 304, and the material supplied from the second gas supply unit 303 to the reaction furnace 301. The gas flow rate is controlled by the second flow rate control unit 305. Of the gas supplied to the reaction furnace 301, the residual gas that remains without being consumed is discharged from the reaction furnace 301 to the exhaust gas treatment unit 308 through the exhaust gas transport pipe 307.

  When forming a thin film on the substrate 310, the gas supplied into the reaction furnace 301 from the first gas supply unit 302 or the second gas supply unit 303 is introduced in a direction perpendicular to the substrate 310. The substrate 310 and the supplied material gas are heated to a desired growth temperature by the heater 312 so that the gas phase chemical reaction on the substrate 310 is promoted.

  Here, the exhaust gas treatment unit 308 will be described. The exhaust gas treatment unit 308 includes a gas abatement unit 313. The exhaust gas treatment unit 308 detoxifies the exhaust gas in the gas detoxification unit 313 and exhausts the detoxified gas to the outside from the exhaust pipe 309. The removal method by the removal unit 313 is generally classified into three types of wet removal, dry removal, and combustion type removal according to the principle of removal or structure.

  The detoxification method by wet detoxification uses an acidic or alkaline solution as a detoxifying agent, and brings the exhaust gas to be treated into contact with the solution, thereby decomposing by a neutralization reaction between the exhaust gas and the solution. . The removal method by wet removal is low-cost, and there are many types of gas that can be processed. However, it is known that the removal method by wet removal is generally low in removal efficiency, and is not suitable for removal of high-concentration toxic gases.

  Next, the detoxification method by dry decontamination uses a porous material such as activated carbon or ceramics with a neutralizing agent or catalyst attached as the detoxifying agent, and the exhaust gas to be treated is physically adsorbed by the detoxifying agent. Or it decomposes | disassembles by making it react chemically. The detoxification method by dry detoxification can be applied to any kind of gas by appropriately combining a porous material and a neutralizing agent or a catalyst. As described above, the removal method by dry removal is versatile and has many kinds of gas that can be treated and high removal efficiency. Therefore, it is the most popular removal method. However, the detoxifying agent used in dry detoxification has a relatively short breakthrough life, and the replacement time as the detoxifying agent is advanced depending on the amount of exhaust gas treated, so that the number of maintenance increases.

  Further, the detoxification method by combustion detoxification involves detoxification by heating the exhaust gas to be treated with a burner, a heater or the like and burning the exhaust gas. The removal method by combustion removal has high removal efficiency and can be realized at a relatively low cost. However, since the type of gas that can be treated is limited to combustible gas, the versatility is low.

  In general, in a MOCVD apparatus, when a plurality of types of gases are used, these material gases are supplied simultaneously or sequentially switched. Therefore, an exhaust gas treatment unit that removes exhaust gas in such an MOCVD apparatus considers the advantages and disadvantages of each of the above-described removal methods in consideration of the type of material gas, the removal efficiency of the entire apparatus, the cost, etc. In many cases, a plurality of abatement methods are combined.

  In particular, in the dry abatement method, a vessel called a heat-resistant and corrosion-resistant abatement tower is filled with a bactericide, and the exhaust gas to be treated is passed through the abatement tower. In general, when a plurality of kinds of material gases are used, a plurality of kinds of detoxifying agents are mixed and filled in one detoxifying tower. Therefore, when the kind of material gas to be used increases, each removal agent will have a bad influence in a removal tower, and the processing capability with respect to each waste gas in a removal tower will fall. In order to solve such a problem, it becomes necessary to make the removal tower large-scale or to increase the replacement frequency of the removal tower.

  In addition, depending on the type of material gas, it may react with a detoxifying agent for detoxifying other material gases, and the detoxifying ability of the detoxifying agent may be significantly reduced. For this reason, selection of the combination of the detoxifying agent according to the type of material gas to be used, maintenance management, etc. are required.

In order to solve the problems related to the exhaust gas treatment part of the MOCVD apparatus as described above, methods for efficiently performing exhaust gas detoxification treatment are disclosed in Patent Documents 1 and 2, for example. In the methods described in Patent Documents 1 and 2, an abatement treatment unit for individually detoxifying two or more kinds of material gases is provided in parallel, and an exhaust gas treatment unit to be used according to the type of material gas to be supplied The process is switched.
Japanese Patent Laying-Open No. 2005-26602 (released on January 27, 2005) JP 2004-124193 A (released on April 22, 2004)

  In the methods described in Patent Documents 1 and 2, the exhaust gas treatment unit to be used is switched according to switching of the supplied material gas. Therefore, immediately after the material gas to be supplied is switched, the material gas supplied before the switching remains in the apparatus. In such a state, there are a plurality of exhaust gases to be processed in the apparatus, and even if the exhaust gas processing section to be processed is switched for each gas, the exhaust gases existing in the apparatus are completely detoxified. There is a problem that harmful gas leaks.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide an exhaust gas treatment apparatus capable of efficiently treating each exhaust gas in an exhaust gas treatment apparatus for treating a plurality of types of exhaust gas. There is to do.

  An exhaust gas treatment apparatus according to the present invention is a gas treatment apparatus that treats two or more types of exhaust gas in order to solve the above-mentioned problem, and is a first that treats exhaust gas mainly containing the first exhaust gas. Gas processing unit and a second gas processing unit for processing exhaust gas mainly containing the second exhaust gas, and the first gas processing unit and the second gas processing unit are respectively the first gas processing unit and the second gas processing unit. Including a first gas abatement part for abatement of the exhaust gas of the first gas and a second gas abatement part for abatement of the second exhaust gas. The harmful part is disposed upstream of the second gas removal part in the exhaust gas inflow direction. In the second gas treatment part, the second gas removal part is the first gas removal part. It is characterized by being arranged upstream of the inflow direction of the exhaust gas with respect to the harm part.

  An exhaust gas treatment method according to the present invention is an exhaust gas treatment method for treating two or more types of exhaust gas in order to solve the above-described problem, and is a first method for treating exhaust gas mainly containing a first exhaust gas. Or a second gas treatment step for treating an exhaust gas mainly containing a second exhaust gas. In the first gas treatment step, the first exhaust gas is included. The second exhaust gas is detoxified after the detoxification process is performed, and in the second gas treatment step, the second exhaust gas is detoxified and then the first exhaust gas is detoxified. It is characterized by performing processing.

  According to said structure, a 1st gas processing part and a 2nd gas processing part respectively detoxify the 1st gas abatement part and 2nd exhaust gas which detoxify 1st exhaust gas A second gas abatement part is provided. As described above, the first gas treatment section includes the second gas removal section as an auxiliary removal section together with the first gas removal section, so that the first gas treatment section is sent to the first gas treatment section. Even if the first exhaust gas thus produced contains the second exhaust gas, both the first exhaust gas and the second exhaust gas can be removed. Similarly, since the second gas processing unit includes the second gas processing unit as an auxiliary abatement unit together with the second gas processing unit, the second gas processing unit is sent to the second gas processing unit. Even if the first gas is contained in the second exhaust gas, it is possible to remove both the first exhaust gas and the second exhaust gas. As a result, exhausted exhaust gas can be sufficiently removed.

  In addition, the first gas processing unit includes the first gas abatement part on the upstream side in the exhaust gas inflow direction with respect to the second gas abatement part. In addition, the second gas processing unit 115 includes a second gas abatement part on the upstream side in the exhaust gas inflow direction with respect to the first gas abatement part. Therefore, the exhaust gas mainly containing the first exhaust gas is detoxified in the first gas processing unit, so that the first exhaust gas is preceded in the first detoxification unit that detoxifies the first exhaust gas. Since the gas is removed and the second exhaust gas remaining thereafter is removed in the second removal unit, the exhaust gas can be removed efficiently. Similarly, the second exhaust gas mainly containing the second exhaust gas is detoxified in the second gas processing unit, so that the second detoxification unit detoxifies the second exhaust gas in advance. Since the first exhaust gas remaining after that is removed by the first removal unit, it is possible to efficiently remove the exhaust gas.

  In the exhaust gas treatment apparatus according to the present invention, in the first gas treatment section, the first gas removal section has a higher removal ability than the second gas removal section, and the second gas treatment section In the part, it is preferable that the removal ability of the second gas removal part is higher than the removal ability of the first gas removal part.

  Depending on the type of exhaust gas, other types of exhaust gas may react with a detoxifying agent to be detoxified to significantly reduce the detoxifying ability of the detoxifying agent. In the first gas treatment unit, the first abatement part is made to be higher than the abatement capacity of the second abatement part by the influence of the second exhaust gas. Even if the detoxification ability of the first exhaust gas is reduced, the first exhaust gas can be sufficiently detoxified because the original detoxification capacity of the first abatement part is high. Similarly, in the second gas processing unit, the second abatement part is configured so that the abatement capacity of the second abatement part is higher than the abatement capacity of the first abatement part, so that the first remaining in the exhaust gas. Even if the abatement ability of the second abatement part is reduced due to the influence of the exhaust gas 1, the abatement ability of the original second abatement part is high, so that the second exhaust gas is sufficiently abolished. It is possible.

  The exhaust gas processing apparatus according to the present invention further includes a processing system switching unit that switches a gas processing unit that processes exhaust gas between the first gas processing unit and the second gas processing unit, and the processing system switching unit includes: When the exhaust gas mainly contained in the exhaust gas is the first exhaust gas, the gas processing unit is switched to the first gas processing unit, while the exhaust gas mainly contained in the exhaust gas. When the gas is the second exhaust gas, it is preferable to switch the gas processing unit to the second gas processing unit.

  As described above, since the gas processing unit is switched according to the type of the exhaust gas mainly mainly contained in the exhaust gas, the gas processing unit can be easily switched. Further, for example, by switching the gas processing unit by the processing system switching unit based on the concentration of the exhaust gas in the exhaust gas, the gas processing unit can be switched more easily.

  The exhaust gas processing apparatus according to the present invention further includes a detection unit that detects the type of exhaust gas mainly contained in the exhaust gas, and a control unit that controls switching of the gas processing unit by the processing system switching unit. The control unit preferably controls the processing system switching unit to switch the gas processing unit that processes the exhaust gas according to the type of the exhaust gas detected by the detection unit. Here, the detection of the type of exhaust gas by the detection unit can be performed, for example, by detecting the exhaust gas having the highest concentration in the exhaust gas. Thereby, it is possible to switch the gas processing unit with higher accuracy, and it is possible to suppress the occurrence of a human operation error and ensure safety.

  In the exhaust gas processing apparatus according to the present invention, the control unit switches the gas processing unit in a state where the total flow rate of the exhaust gas flowing into the first gas processing unit and the second gas processing unit is kept constant. It is preferable to control the processing system switching unit. Thereby, it is possible to suppress the fluctuation of the pressure in the apparatus due to a sudden change in the total flow rate of the exhaust gas. As a result, since the gas flow in the apparatus during the thin film formation process is not disturbed, the gas processing section can be switched without deteriorating the film formation quality.

In the exhaust gas treatment apparatus according to the present invention, it is preferable that one of the first exhaust gas and the second exhaust gas is NH ₃ gas and the other is AsH ₃ gas. In addition, the thin film forming layer value according to the present invention is a thin film forming apparatus that forms a thin film on a substrate using two or more kinds of material gases, and preferably includes any one of the above-described exhaust gas treatment apparatuses. . In the exhaust gas treatment apparatus according to the present invention, various types of exhaust gas can be sufficiently detoxified, and thus can be applied to various thin film forming apparatuses.

  As described above, the exhaust gas treatment apparatus according to the present invention is the exhaust gas treatment apparatus for treating two or more types of exhaust gas, and the first gas treatment unit for treating the exhaust gas mainly containing the first exhaust gas; A second gas processing unit that processes exhaust gas mainly containing the second exhaust gas, wherein the first gas ablation unit is a second gas ablation unit. In the second gas processing unit, the second gas abatement part is disposed upstream of the exhaust gas inflow direction with respect to the first gas abatement part. For example, even if a plurality of types of exhaust gas are mixed in the exhaust gas, the process for the main exhaust gas contained in the exhaust gas is preceded in the gas processing unit for one exhaust gas. And then processing other exhaust gases Since kill, it is possible to process multiple types of exhaust gas sufficiently, respectively.

(First embodiment)
An embodiment of a thin film forming apparatus according to the present invention will be described below with reference to FIG. FIG. 1 is a schematic configuration diagram showing a thin film forming apparatus 100 according to an embodiment of the present invention. As shown in FIG. 1, a thin film forming apparatus 100 includes a reaction furnace 101, a first gas supply unit 102, a second gas supply unit 103, a first flow rate control unit 104, a second flow rate control unit 105, and a supply. A pipe 106, an exhaust gas transport pipe 107, an exhaust gas treatment unit (exhaust gas treatment device) 108, and an exhaust pipe 109 are provided. In the reaction furnace 101, a susceptor 111 and a heater 112 are provided. The substrate 110 is placed on a counterbore formed on the outer periphery of the substrate 110 at the center of the susceptor 111, and the heater 112 and the susceptor 111 together with the substrate 110. Is supposed to heat.

  The exhaust gas processing unit 108 includes a processing system switching unit 113, a first gas processing unit 114, and a second gas processing unit 115, and the first gas processing unit 114 includes the first gas abatement unit 116 and The second gas removal unit 117 is provided, and the second gas processing unit 115 includes a second gas removal unit 118 and a first gas removal unit 119.

  The first gas supply unit 102 and the second gas supply unit 103 supply material gas for forming a thin film on the substrate 110 to the reaction furnace 101, and are supplied to the reaction furnace 101 via the supply pipe 106. It is connected. The flow rate of the material gas supplied from the first gas supply unit 102 to the reaction furnace 101 is controlled by the first flow rate control unit 104, and is supplied from the second gas supply unit 103 to the reaction furnace 101. The flow rate of the material gas is controlled by the second flow rate control unit 105. The first flow rate control unit 104 and the second flow rate control unit 105 control the supply flow rate of the material gas supplied from the first gas supply unit 102 or the second gas supply unit 103 to the reaction furnace 101. Yes, a mass flow controller or the like can be suitably used.

In the present embodiment, the first material gas supplied from the first gas supply unit 102 to the reaction furnace 101 is different from the second material gas supplied from the second gas supply unit 103 to the reaction furnace 101. For example, one may be NH ₃ gas and the other may be AsH ₃ gas, but is not limited thereto. In the present embodiment, the configuration using two types of material gas is described, but the same effect can be obtained even when three or more types of material gas are used. In this case, a gas supply unit, a flow rate control unit, a gas processing unit, a gas abatement unit, and the like are installed according to the type of material gas.

  The material gas supplied from the first gas supply unit 102 or the second gas supply unit 103 to the reaction furnace 101 is used as a material for forming a thin film on the substrate 110 in the reaction furnace 101. In the reaction furnace 101, the substrate 110 is placed in a counterbore formed so as to indicate the back side of the substrate 110 at the center of the susceptor 111. When forming a thin film on the substrate 110, the material gas supplied into the reaction furnace 101 is introduced in a direction perpendicular to the substrate 110. At this time, the substrate 110 is heated to a desired growth temperature by the heater 112, and the gas phase reaction of the material gas on the substrate 101 is promoted to form a thin film.

  In the case of forming a thin film on the substrate 101 by MOCVD, a desired thin film is formed by supplying two or more kinds of material gases to the substrate 101 by switching appropriately. In the thin film forming apparatus 100 according to the present invention, the first material gas and the second material gas are appropriately switched and supplied onto the substrate 110 in the reaction furnace 101 so that a desired thin film can be formed on the substrate 101. To do. In the present embodiment, the switching of the supply of the material gas is realized by adjusting the supply flow rate of the material gas supplied to the reaction furnace 101 by the first flow rate control unit 104 or the second flow rate control unit 105. Can do. Further, the switching of the supply of the material gas may be realized by adjusting the open / close state of a valve for supplying the material gas to the reaction furnace 101.

  The reaction furnace 101 is connected to an exhaust gas treatment unit 108 via an exhaust gas transport pipe 107. The unreacted material gas that has not been used for forming the thin film in the reaction furnace 101 is sent to the exhaust gas treatment unit 108 via the exhaust gas transport pipe 107. Since such unreacted material gas contains harmful substances, it is detoxified in the exhaust gas treatment unit 108 before being exhausted outside the apparatus. Then, the exhaust gas removed by the exhaust gas processing unit 108 is exhausted from the exhaust pipe 109 to the outside of the apparatus.

  In this specification, the exhaust gas detoxification is intended to detoxify harmful substances contained in the exhaust gas, and not only completely detoxify harmful substances contained in the exhaust gas, but also exhaust gas. It is also intended to reduce the content of harmful substances in the gas to the desired ratio.

  Here, the exhaust gas detoxification process in the exhaust gas treatment unit 108 will be described. As described above, since the reaction furnace 101 is supplied with the first material gas and the second material gas, the exhaust gas exhausted without being used for forming the thin film is also the first exhaust gas. There are two types of gas and second exhaust gas. In the present embodiment, the exhaust gas treatment unit 108 individually removes two types of exhaust gas.

  The exhaust gas sent to the exhaust gas processing unit 108 is sent to the first gas processing unit 114 or the second gas processing unit 115 via the processing system switching unit 113. The piping from the processing system switching unit 113 to each gas processing unit is branched. The processing system switching unit 113 switches the gas processing unit that performs processing according to the type of exhaust gas sent from the reaction furnace 101. Switching of the gas processing unit by the processing system switching unit 113 is performed, for example, by switching to a gas processing unit that mainly processes the gas having the highest concentration in the exhaust gas. The processing system switching unit 113 may be any unit that allows exhaust gas to flow into a pipe branched to the first gas processing unit 114 or the second gas processing unit 115 according to the type of exhaust gas, such as a valve. Can be suitably used.

  The first gas processing unit 114 processes the first exhaust gas exhausted to the exhaust gas processing unit 108 in an unreacted state among the first material gas supplied from the first gas supply unit 102. is there. In addition, the second gas processing unit 115 processes the second exhaust gas exhausted to the exhaust gas processing unit 108 without being reacted among the second material gas supplied from the second gas supply unit 103. Is. Therefore, the processing system switching unit 113 switches the processing system for processing the exhaust gas to the first gas processing unit 114 when the first exhaust gas is exhausted from the reaction furnace 101, and the second exhaust gas. When the gas is exhausted, the second gas processing unit 115 is switched.

  During the formation of the thin film, a plurality of material gases are sequentially switched and supplied to the reaction furnace 101, and exhaust gases not used in the reaction are sequentially sent to the exhaust gas treatment unit 108. The supplied material gas remains in the reaction furnace 101 and the exhaust gas transport pipe 107. Therefore, the exhaust gas sent to the exhaust gas treatment unit 108 may include both the first exhaust gas and the second exhaust gas. In such a case, the gas processing unit that removes only one of the exhaust gases cannot remove the other exhaust gas, and is exhausted to the outside while containing a large amount of harmful substances.

  In the exhaust gas processing unit 108 according to the present embodiment, the first gas processing unit 114 and the second gas processing unit 115 are the first gas abatement units 116 and 119 for detoxifying the first exhaust gas, respectively. And second gas abatement sections 117 and 118 for detoxifying the second exhaust gas. Thus, since the 1st gas treatment part 114 is provided with the 2nd gas removal part 117 as an auxiliary removal part with the 1st gas removal part 116, it is the 1st gas treatment part. Even if the second exhaust gas is contained in the first exhaust gas sent to the section 114, it is possible to remove both the first exhaust gas and the second exhaust gas. Similarly, since the second gas treatment unit 115 includes the second gas removal unit 119 as an auxiliary removal unit together with the second gas removal unit 118, the second gas treatment unit 115 includes the second gas removal unit 119. Even if the first gas is contained in the second exhaust gas sent to the processing unit 115, both the first exhaust gas and the second exhaust gas can be removed. As a result, exhaust gas exhausted from the reaction furnace 101 can be sufficiently removed.

  In the present embodiment, the first gas abatement sections 116 and 119 and the second gas abatement sections 117 and 118 each include a detoxifying agent for detoxifying the exhaust gas to be processed. Such a detoxifying agent may be an acid or alkaline solution in wet detoxification, or may be a neutralizing agent, catalyst, adsorbent or the like in dry detoxification, but is not limited thereto. The detoxification method, the type of the detoxifying agent, the amount of the detoxifying agent used, and the like can be appropriately selected according to the type of exhaust gas (the type of material gas used for forming the thin film).

  In addition, the first gas processing unit 114 includes a first gas removing unit 116 on the upstream side in the exhaust gas inflow direction with respect to the second gas removing unit 117. That is, the exhaust gas sent to the first gas processing unit 114 is first subjected to the detoxification process in the first gas abatement part 116 and then detoxified in the second gas abatement part 117. In addition, the second gas processing unit 115 includes a second gas removing unit 118 on the upstream side in the exhaust gas inflow direction with respect to the first gas removing unit 119. That is, the exhaust gas sent to the second gas processing unit 115 is first subjected to the detoxification process in the second gas abatement part 118 and then detoxified in the first gas abatement part 119.

  Accordingly, the first exhaust gas mainly containing the first exhaust gas is removed by the first gas processing unit 114, so that the first removal unit 116 that removes the first exhaust gas precedes the first. Since the second exhaust gas remaining after that is removed by the second removal unit 117, it is possible to efficiently remove the exhaust gas. Similarly, the exhaust gas exhaust gas mainly containing the second exhaust gas is detoxified in the second gas processing unit 115, so that the second detoxification unit 118 detoxifies the second exhaust gas. Since the second exhaust gas is detoxified, and the first exhaust gas remaining thereafter is detoxified by the first abatement part 119, the exhaust gas can be efficiently detoxified.

  Furthermore, in the first gas treatment unit 114, it is preferable that the gas removal capability of the first gas removal unit 116 is higher than the gas removal capability of the second gas removal unit 117. Similarly, in the second gas treatment unit 115, it is preferable that the gas removal capability of the second gas removal unit 118 is higher than the gas removal capability of the first gas removal unit 119. Here, the abatement ability is intended for abatement efficiency or abatement performance, and is intended to be capable of abatement of gas. By appropriately selecting the detoxifying agent to be used, the gas detoxifying ability of the gas detoxifying part can be changed. For example, by selecting a detoxifying agent with a higher detoxifying capacity, increasing the amount of the detoxifying agent used, or selecting a detoxifying method with a higher detoxifying capacity, etc. be able to.

  Depending on the type of exhaust gas, other types of exhaust gas may react with a detoxifying agent to be detoxified to significantly reduce the detoxifying ability of the detoxifying agent. That is, when the exhaust gas mainly containing the first exhaust gas is detoxified, in the first gas processing unit 114, the detoxifying ability of the first abatement unit 116 is the second abatement unit 117. If the detoxifying capacity is lower than the detoxifying capacity of the first detoxifying unit 116, the detoxifying agent used in the first detoxifying unit 116 reacts with the second exhaust gas remaining in the exhaust gas. There is a possibility of significantly reducing the ability to harm.

  At this time, if the removal ability of the first removal unit 116 is higher than the removal ability of the second removal unit 117, the removal ability of the first removal unit 116 due to the influence of the second exhaust gas. However, since the first abatement part 116 has a high detoxifying ability, the first exhaust gas can be sufficiently detoxified. Moreover, since the content of the second exhaust gas contained in the exhaust gas processed in the first gas processing unit 114 is lower than the content of the first exhaust gas, the second gas abatement unit Even if the abatement ability of 117 is lower than the abatement capacity of the first gas abatement part 116, the second exhaust gas can be sufficiently abolished.

  By configuring the second gas processing unit 115 in the same manner, even if the abatement ability of the second abatement unit 118 is reduced due to the influence of the first exhaust gas remaining in the exhaust gas, Since the removal capability of the second abatement part 118 is high, the second exhaust gas can be sufficiently eliminated.

(Second Embodiment)
Another embodiment of the thin film forming apparatus according to the present invention will be described below with reference to FIG. FIG. 2 is a schematic configuration diagram showing a thin film forming apparatus 200 according to another embodiment of the present invention. A thin film forming apparatus 200 shown in FIG. 2 is similar to the thin film forming apparatus 100 shown in FIG. 1 in that a reaction furnace 101, a first gas supply unit 102, a second gas supply unit 103, a first flow rate control unit 104, A second flow rate control unit 105, a supply pipe 106, an exhaust gas transport pipe 107, an exhaust gas processing unit 108, and an exhaust pipe 109 are provided. In the reaction furnace 101, a susceptor 111 and a heater 112 are provided. The substrate 110 is placed on a counterbore formed on the outer periphery of the substrate 110 at the center of the susceptor 111, and the heater 112 and the susceptor 111 together with the substrate 110. Is supposed to heat.

  The exhaust gas processing unit 108 includes a processing system switching unit 113, a first gas processing unit 114, and a second gas processing unit 115, and the first gas processing unit 114 includes the first gas abatement unit 116 and The second gas removal unit 117 is provided, and the second gas processing unit 115 includes a second gas removal unit 118 and a first gas removal unit 119. Since these configurations of the thin film forming apparatus 200 according to the present embodiment are the same as those of the thin film forming apparatus 100 according to the first embodiment, detailed description thereof is omitted.

  The thin film forming apparatus 200 according to the present embodiment further includes a detection unit 201 and a control unit 202. The detection unit 201 detects the type of exhaust gas mainly contained in the exhaust gas, and the control unit 202 processes the exhaust gas according to the type of exhaust gas detected by the detection unit 201. The processing system switching unit 113 is controlled so as to switch the gas processing unit.

  The detection unit 201 detects the type of exhaust gas flowing through the exhaust gas transport pipe 107. More specifically, the existence ratio of the exhaust gas flowing through the exhaust gas transport pipe 107 is detected. Thereby, the gas with the highest abundance ratio in the exhaust gas can be detected as a gas mainly contained in the exhaust gas. In order to monitor the absolute amount of gas molecules passing through the exhaust gas treatment unit 108, the detection unit 201 preferably detects the exhaust gas flow rate together with the exhaust gas abundance ratio. Furthermore, the detection unit 201 may be configured to detect the concentration of gas flowing in the exhaust gas transport pipe 107.

  The detector 201 further detects the pressure in the supply pipe 106 and the exhaust gas transport pipe 107, the supply state from the first gas supply part 102 and the second gas supply part 103 (supply start or supply end point, and material gas). (Elapsed time after opening / closing of the valve for supply) is preferably detected. Based on such a plurality of pieces of information, the type of exhaust gas mainly contained in the exhaust gas can be detected more accurately.

  The detection unit 201 is a pressure sensor that detects pressure, such as a concentration meter that detects the concentration of gas passing through the supply pipe 106 and the exhaust gas transport pipe 107, a detector, a flow meter that detects the gas flow rate, a mass flow controller, and the like. Etc., such as gas chromatography for detecting the gas abundance ratio, QMAS, etc., can be configured by a valve for detecting the supply state from the gas supply unit, a timer, etc., and one or more of these may be provided .

  The control unit 202 controls the processing system switching unit 113 based on each information detected by the detection unit 201 described above. For example, when the exhaust gas having the highest concentration in the exhaust gas or having reached a certain concentration detected by the detection unit 201 is the first exhaust gas, the gas processing unit is replaced with the first gas processing unit 114. The processing system switching unit 113 is controlled to switch to. Then, when the exhaust gas having the highest concentration in the exhaust gas or having reached a certain concentration detected by the detection unit 201 is the second exhaust gas, the gas processing unit is replaced with the second gas processing unit 115. Switch to. As described above, in the present invention, control is performed so as to switch the gas processing unit that removes the exhaust gas according to the type of the exhaust gas contained in the exhaust gas, so the exhaust gas is removed more efficiently. It is possible.

  As a specific processing system switching condition, for example, when the gas mainly flowing through the exhaust gas transport pipe 107 is the first exhaust gas, the second gas abatement unit 118 in the first gas processing unit 114 The gas processing unit is switched to the second gas processing unit 115 when the content rate of the second exhaust gas in the exhaust gas flowing through the exhaust gas transport pipe 107 reaches 80 to 90% with respect to the processing limit. The control unit 202 may control the processing system switching unit 113. Here, the processing limit of the gas abatement part is the limit (specification) of the abatement ability set in advance by the concentration and flow rate of the gas to be used to the maximum. That is, if the gas abatement part is used under conditions that exceed the set processing limit, the exhaust gas passes through without being completely detoxified.

  When exhausting exhaust gas using a plurality of gas processing units, it is difficult to adjust the timing to switch the gas processing unit, human error is likely to occur, and it does not switch well to the desired gas processing unit, There was a risk of releasing harmful gases into the atmosphere without exhausting the exhaust gas. According to the present invention, by switching the gas processing unit based on the information obtained from the detection unit 201, the control unit 202 can suppress the occurrence of a human operation error and ensure safety.

  Further, the control unit 202 may control the processing system switching unit 113 based on preset recipe information. The recipe information includes the time from when the material gas is supplied to the reaction furnace 101 until it reaches the exhaust gas treatment unit 108, the combination of the types of material gas used, the flow rates of the material gas and the exhaust gas, and the gas in the reaction furnace 101. Temperature. Such recipe information can be set based on information obtained when the thin film forming apparatus 200 has been operated in the past. Therefore, the thin film forming apparatus 200 may further include a storage unit (not shown) that stores recipe information, past operation information, conditions for setting recipe information from past operation information, and the like.

  When the control unit 202 controls the processing system switching unit 113 based on the recipe information, for example, flag information indicating that the first material gas included in the recipe information is used, and the first from the detection unit 201 Based on the information indicating that the valve for supplying the gas supply unit 102 is open, the control unit 202 sets the processing system switching unit 113 to switch the gas processing unit to the first gas processing unit 114. Control. Thereby, according to the use conditions of material gas, a gas processing part can be switched appropriately, ensuring safety.

  The control unit 202 preferably switches the gas processing unit so that the total flow rate of the exhaust gas in the exhaust gas processing unit 108 is kept constant when the gas processing unit is switched by the processing system switching unit 113. Further, the control unit 202 preferably controls the processing system switching unit 113 so that the total flow rate of the exhaust gas in the exhaust gas processing unit 108 does not change abruptly. Specifically, the control unit 202 controls the processing system switching unit 113 so as to switch the gas processing unit slowly.

  For example, the control unit 202 controls the mass flow controller as the processing system switching unit 113, and automatically adjusts the opening degree so that the flow rate becomes a desired set value, thereby rapidly changing the total flow rate of the exhaust gas. Control not to. The mass flow controller can keep the flow rate constant, but it is difficult to cope with a rapid change. Therefore, it is preferable to slowly switch the gas processing unit by the processing system switching unit 113. When the gas processing unit is switched slowly, the exhaust gas flows through both the first gas processing unit 114 and the second gas processing unit 115. In addition, for example, the generation of a sudden pressure difference at the time of switching may be absorbed by using a pressure adjustment line that combines a differential pressure sensor such as a Baratron, a relief valve, and a purge line.

  When the total flow rate of the exhaust gas changes suddenly by switching the gas processing unit, the pressure in the apparatus fluctuates, so that the gas flow in the reaction furnace 101 during the thin film formation process is disturbed, adversely affecting the thin film growth conditions, There was a problem that the film-forming quality was significantly lowered. In the thin film forming apparatus 200 according to the present embodiment, the control unit 202 includes an exhaust gas in order to ensure the safety and reliability of the apparatus and perform high-yield vapor phase growth without deteriorating the film formation quality. Since the processing system switching unit 113 is controlled so that the total flow rate of the exhaust gas in the processing unit 108 does not change abruptly, it is possible to suppress pressure fluctuations in the apparatus due to the switching of the gas processing unit. It is possible to suppress the occurrence of gas turbulence and to prevent the film quality from deteriorating.

  As described above, according to the thin film forming apparatus of the present invention, even when a plurality of gases are included in the exhaust gas, these gases can be sufficiently removed. Furthermore, the thin film forming apparatus according to the present invention can suppress the occurrence of human operation mistakes, ensure safety, and prevent deterioration in film formation quality.

  The present invention can also be expressed as follows.

(First configuration)
In an exhaust gas treatment system of a MOCVD apparatus including a gas supply unit that supplies two or more kinds of gases, a reaction furnace, and a gas exhaust unit, the gas exhaust unit branches to provide a first abatement capability for gas A A gas treatment unit provided with a detoxification device and a detoxification device having a second detoxification capability for gas B in this order along the flow direction, and a first detoxification capability for gas B The abatement device and the abatement device having the second abatement capability for the gas A are divided into the B gas processing section provided in this order along the flow direction, and the gas passing through the gas exhaust section is An exhaust gas treatment system for an MOCVD apparatus, comprising a treatment system switching device for switching to a gas treatment unit or a B gas treatment unit.

(Second configuration)
An exhaust gas treatment system for an MOCVD apparatus, wherein the first abatement capacity for the gas is larger than the second abatement capacity.

(Third configuration)
In the MOCVD apparatus, a plurality of state detection devices for detecting a set state of a gas to be used, and a control unit for controlling the processing system switching device based on information obtained from the state detection device are provided. Thus, in switching between the A gas processing unit and the B gas processing unit, the processing system is switched and controlled so as to keep the total flow rate of the exhausted gas constant. Exhaust gas treatment system for MOCVD equipment.

(Fourth configuration)
The gas A and the gas B are NH3 gas and AsH3 gas, respectively, according to the first to third configurations of the exhaust gas treatment system for an MOCVD apparatus.

(Fifth configuration)
In an exhaust gas treatment method for an MOCVD apparatus including a gas supply unit that supplies two or more kinds of gases, a reaction furnace, and a gas exhaust unit, the gas exhaust unit is branched and has a first abatement capability for gas A A gas treatment unit provided with a detoxification means and a detoxification means having a second detoxification capability for gas B in this order along the flow direction, and a first detoxification capability for gas B The abatement means and the abatement means having the second abatement ability for the gas A are divided into the B gas processing section provided in this order along the flow direction, and the gas passing through the gas exhaust section is An exhaust gas treatment method for an MOCVD apparatus, comprising a processing system switching means for switching to a gas processing unit or a B gas processing unit.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  According to the present invention, exhaust gas can be efficiently removed, so that it can contribute to various manufacturing fields by being applied to various thin film forming apparatuses.

It is a schematic block diagram which shows the thin film forming apparatus which concerns on one Embodiment of this invention. It is a schematic block diagram which shows the thin film forming apparatus which concerns on one Embodiment of this invention. It is a schematic block diagram which shows the conventional thin film forming apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 * 200 Thin film forming apparatus 108 Exhaust gas processing apparatus 113 Processing system | strain switching part 114 1st gas processing part 115 2nd gas processing part 116 * 119 1st abatement part 117 * 118 2nd abatement part 201 Detection part 202 Control unit

Claims (8)

An exhaust gas treatment apparatus for treating two or more types of exhaust gas,
A first gas processing unit for processing exhaust gas mainly containing the first exhaust gas;
A second gas processing unit for processing exhaust gas mainly containing the second exhaust gas,
The first gas processing unit and the second gas processing unit respectively include a first gas ablation unit that ablates the first exhaust gas, and a second gas ablation unit that abates the second exhaust gas. Part and
In the first gas treatment part, the first gas abatement part is disposed upstream of the second gas abatement part in the exhaust gas inflow direction,
In the second gas treatment unit, the second gas removal unit is disposed on the upstream side in the exhaust gas inflow direction with respect to the first gas removal unit. In the first gas treatment section, the first gas removal section has a higher removal ability than the second gas removal section,
2. The exhaust gas treatment apparatus according to claim 1, wherein in the second gas treatment unit, the detoxification ability of the second gas removal unit is higher than the removal ability of the first gas removal unit. A processing system switching unit that switches a gas processing unit that processes exhaust gas between the first gas processing unit and the second gas processing unit;
The processing system switching unit
When the exhaust gas mainly contained in the exhaust gas is the first exhaust gas, the gas processing unit is switched to the first gas processing unit,
The exhaust gas treatment according to claim 1 or 2, wherein when the exhaust gas mainly contained in the exhaust gas is the second exhaust gas, the gas processing unit is switched to the second gas processing unit. apparatus. A detection unit for detecting the type of exhaust gas mainly contained in the exhaust gas, and a control unit for controlling switching of the gas processing unit by the processing system switching unit,
The said control part controls the said processing system switching part so that the gas processing part which processes exhaust gas may be switched according to the kind of exhaust gas detected in the said detection part. Exhaust gas treatment equipment.   The control unit controls the processing system switching unit to switch the gas processing unit in a state where the total flow rate of the exhaust gas flowing into the first gas processing unit and the second gas processing unit is kept constant. The exhaust gas treatment apparatus according to claim 4.   6. The exhaust gas treatment apparatus according to claim 1, wherein one of the first exhaust gas and the second exhaust gas is ammonia gas, and the other is allicin gas. A thin film forming apparatus for forming a thin film on a substrate using two or more kinds of material gases,
A thin film forming apparatus comprising the exhaust gas treatment apparatus according to any one of claims 1 to 6. An exhaust gas treatment method for treating two or more types of exhaust gas,
At least one of a first gas treatment step for treating exhaust gas mainly containing the first exhaust gas and a second gas treatment step for treating exhaust gas mainly containing the second exhaust gas Contains
In the first gas treatment step, after the detoxification process for the first exhaust gas, the detoxification process for the second exhaust gas is performed,
In the second gas treatment step, the exhaust gas treatment method is characterized in that after the detoxification process is performed on the second exhaust gas, the first exhaust gas is detoxified.

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