JP2001000837A - Waste gas treating device for semiconductor production device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently treat fluoride which is chemically stable by connecting a branched route for removing the waste gas discharged from a semiconductor production device at a proceeding stage of a vacuum pump and disposing a vacuum pump for sucking the waste gas and a device for treating the fluoride in the waste gas. SOLUTION: The branched route 11 is connected at the proceeding stage of the vacuum pump 5 provided at a waste gas route 2 from the semiconductor production device 1 to a waste gas treating device 3 by interposing the vacuum pump 5. Then a pretreating device 7, a vacuum pump 12 and a fluoride recovering device 4 are disposed in order at the branched route 11. In other words, the branched route 11 is disposed for removing the waste gas from the waste gas route 2 and for sending the waste gas to the fluoride recovering device 4 when the waste gas containing the fluoride which is chemically stable is discharged from the semiconductor production device 1, and a pair of switching valves 13 and 14 for switching a waste gas flow direction are provided at the waste gas route 2 and a branched part of the branched route 11. In this way, the recovery of the fluoride is efficiently executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas treatment apparatus for a semiconductor manufacturing apparatus, and more particularly, to an efficient treatment of an exhaust gas discharged from a semiconductor manufacturing process and a treatment of a fluoride contained in the exhaust gas. The present invention relates to an exhaust gas treatment apparatus for a semiconductor manufacturing apparatus that can be performed well.

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, harmful substances and flammable substances including volatile inorganic hydrides such as silane and arsine are used as raw materials for forming a thin film. The exhaust gas is discharged through an exhaust gas treatment device that performs these detoxification and removal.

Further, in the semiconductor manufacturing process, fluorides such as perfluorocarbon, hydrofluorocarbon, nitrogen trifluoride and sulfur hexafluoride are used in the etching process and the chamber cleaning process, and are discharged from the semiconductor manufacturing process. These fluorides are contained in the exhaust gas. Since such a fluoride is a substance causing global warming, it is necessary to remove the exhaust gas before releasing it to the atmosphere.

[0004] From this, as shown in FIG.
An exhaust gas treatment device 3 for treating harmful substances other than fluoride and a fluoride collection device 4 for treating, for example, collecting, fluoride are installed in a path 2 of the exhaust gas discharged from the semiconductor manufacturing apparatus 1. In addition, these substances are selectively used depending on the composition of the exhaust gas, and both harmful substances and fluorides are treated by a method such as thermal decomposition.

The exhaust gas path 2 is provided with a vacuum pump 5 for sucking the exhaust gas from the semiconductor manufacturing apparatus 1 and sending the exhaust gas to the exhaust gas processing apparatus 3 and the fluoride recovery apparatus 4. The protective gas path 6 is used to prevent a reactive gas, for example, silicon or silicon dioxide generated by decomposition or reaction of silane from adhering to the vacuum pump and blocking the vacuum pump 5 due to this. A large amount of gas for pump protection such as nitrogen gas is introduced to dilute the reactive gas. Note that a pretreatment device 7 for removing a substance that hinders the operation of recovering fluoride in the recovery device 4 is provided at a stage preceding the fluoride recovery device 4.

[0006]

As described above, when a large amount of pump protecting gas is introduced into the vacuum pump 5, there is almost no problem in the detoxification treatment in the exhaust gas treatment device 3, but the fluoride in the exhaust gas Is diluted and the concentration is reduced, so that in the fluoride recovery device 4, a large amount of energy is required to obtain a required recovery rate and recovery concentration, and there is a problem that the processing cost increases.

Further, since the above-mentioned fluoride is a compound which is very stable and difficult to decompose, even if it is decomposed without being recovered, it must be performed at a high temperature of about 1000 ° C. In addition to the high processing cost, there is a problem that harmful substances such as solid waste and hydrofluoric acid are generated in large quantities.

Accordingly, an object of the present invention is to provide an exhaust gas treatment apparatus for a semiconductor manufacturing apparatus capable of efficiently processing chemically stable fluoride contained in exhaust gas from the semiconductor manufacturing apparatus.

[0009]

In order to achieve the above object, an exhaust gas treatment apparatus for a semiconductor manufacturing apparatus according to the present invention comprises a vacuum pump for sucking exhaust gas discharged from the semiconductor manufacturing apparatus and sending the exhaust gas to the exhaust gas processing apparatus. In addition, in an exhaust gas treatment apparatus for a semiconductor manufacturing apparatus provided with a path for introducing a pump protection gas for preventing blockage to the vacuum pump, a chemically stable pump discharged from the semiconductor manufacturing apparatus is provided upstream of the vacuum pump. A branch path for taking out an exhaust gas containing fluoride is connected via a switching means, and a vacuum pump for sucking the exhaust gas containing fluoride and a fluoride processing apparatus for treating the fluoride are provided on the branch path. It is characterized by that.

[0010]

FIG. 1 is a system diagram showing one embodiment of an exhaust gas treatment apparatus for a semiconductor manufacturing apparatus according to the present invention. This exhaust gas treatment apparatus for a semiconductor manufacturing apparatus is a semiconductor manufacturing apparatus 1
A branch path 1 is provided in front of the vacuum pump 5 provided in the exhaust gas path 2 from the vacuum pump 5 to the exhaust gas treatment device 3 via the vacuum pump 5.
1, a pretreatment device 7, a vacuum pump 12, and a fluoride recovery device 4 are provided in the branch path 11.

The branch path 11 is used to take out the exhaust gas from the exhaust gas path 2 and send it to the fluoride recovery apparatus 4 when exhaust gas containing chemically stable fluoride is discharged from the semiconductor manufacturing apparatus 1. Exhaust gas path 2
A pair of switching valves 13 and 14 is provided as a switching means for switching the flow direction of the exhaust gas at a branch portion between the flow path and the branch path 11.
Are provided respectively.

The exhaust gas treatment apparatus thus formed can efficiently recover fluoride by switching the switching valves 13 and 14 in accordance with the process of the semiconductor manufacturing apparatus 1. That is, while the semiconductor manufacturing apparatus 1 is performing the thin film forming process, the switching valve 13 is opened and the switching valve 14 is closed because silane, arsine, and the like used as the raw materials are discharged into the exhaust gas. As a result, the exhaust gas containing these harmful components can be sucked by the vacuum pump 5 and introduced into the exhaust gas treatment device 3, and the harmful components in the exhaust gas can be treated in the same manner as in the related art. At this time, the protective gas path 6 is connected to the vacuum pump 5 as in the conventional case.
A large amount of gas for pump protection is introduced from the pump to prevent solids such as reaction products from adhering to the inside of the pump.

On the other hand, while the etching process and the chamber cleaning process are being performed in the semiconductor manufacturing apparatus 1, a large amount of fluoride used in these processes is contained in the exhaust gas, and the harmful components are almost not contained. Therefore, the switching valve 13 is closed and the switching valve 14 is opened to flow the exhaust gas to the branch path 11.

The exhaust gas that has flowed into the branch path 11 is a substance that interferes with the fluoride collection operation in the fluoride collection unit 4 in the pretreatment unit 7 and a substance that interferes with the operation of the vacuum pump 12 in the subsequent stage. After being removed, it is introduced into the fluoride recovery device 4 via the vacuum pump 12, and a fluoride recovery operation is performed. Therefore, since the operation of recovering the fluoride can be performed on the exhaust gas not diluted with the pump protection gas, the concentration of the fluoride to be recovered becomes higher than before, and the fluoride is efficiently recovered. be able to.

The fluorides to be collected include various perfluorocarbons, various hydrofluorocarbons,
Chemically stable fluorides such as nitrogen trifluoride and sulfur hexafluoride, and unstable and highly reactive fluorides such as silicon tetrafluoride, carbonyl difluoride and hydrogen fluoride are used in pretreatment equipment. In step 7, it is separated and removed in advance. The substances to be removed by the pretreatment device 7 include, for example, harmful components such as silane discharged from the semiconductor manufacturing device 1, solids such as silicon and silicon dioxide, and solidified when cooled by a chlorofluorocarbon recovery operation. The target is impurities such as water and carbon dioxide. This pretreatment can be performed by a well-known method by using an appropriate adsorbent or a scavenger.

The operation of recovering fluoride in the fluoride recovery device 4 can be performed by various methods conventionally used, for example, a method of adsorbing on an adsorbent such as activated carbon, or a method of contacting with a liquid fluoride. A method of causing absorption or the like can be appropriately adopted, and is not particularly limited.
In addition, even when the fluoride is decomposed without being recovered, it can be performed more efficiently than when the concentration is low.

[0017]

As described above, according to the exhaust gas treating apparatus for a semiconductor manufacturing apparatus of the present invention, while only removing harmful components in the same manner as in the prior art, only the exhaust gas containing a high concentration of fluoride is converted into fluoride. Since it can be introduced into the processing apparatus, the processing of the fluoride, particularly the recovery, can be performed efficiently, and the energy required for the recovery can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a system diagram showing one embodiment of an exhaust gas treatment apparatus for a semiconductor manufacturing apparatus according to the present invention.

FIG. 2 is a system diagram showing an example of a conventional exhaust gas treatment apparatus for a semiconductor manufacturing apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Semiconductor manufacturing apparatus, 2 ... Exhaust gas path, 3 ... Exhaust gas treatment apparatus, 4 ... Fluoride recovery apparatus, 5 ... Vacuum pump, 6 ... Protective gas path, 7 ... Pretreatment apparatus, 11 ... Branch path, 12
... Vacuum pumps, 13, 14 ... Switching valves

Claims (1)

[Claims] 1. A semiconductor manufacturing apparatus comprising: a vacuum pump for sucking exhaust gas discharged from a semiconductor manufacturing apparatus and sending the exhaust gas to an exhaust gas processing apparatus; and a path for introducing a pump protection gas for preventing blockage to the vacuum pump. In the exhaust gas treatment device for an apparatus, a branch path for taking out an exhaust gas containing chemically stable fluoride discharged from the semiconductor manufacturing apparatus is connected to the preceding stage of the vacuum pump through a switching means, and the branch path is connected to the branch path. An exhaust gas treatment apparatus for a semiconductor manufacturing apparatus, comprising: a vacuum pump for sucking the exhaust gas containing the fluoride; and a fluoride treatment device for treating the fluoride.