JPH04150903A - Trap device - Google Patents

Abstract

PURPOSE:To make possible the control of a lowering in the capacity of an exhaust emission system caused by the volatile components in captured substances by providing a capture mechanism for harmful substances with a mechanism for heating the substances captured thereby. CONSTITUTION:A trap device 1 adapted to be freely detachably inserted into an exhaust emission system is provided with a cooling jacket 3, a cooling fin 6 and a cooling water conduit pipe 9 to cool the gas flowing through the exhaust emission system, thereby capturing the org. substances contained in the gas. This capture mechanism is provided with a heater 8 for heating the captured substances. As a result, since the volatile components contained in the captured substances can be easily removed in a short time, a lowering in the capacity of the exhaust emission system caused by the volatile components can be controlled. Therefore, the treating quality of a semiconductor production device connected with this trap device can be maintained at a stable level and a lowering in the operation factor accompanied by the trap device cleaning can be prevented.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a trap device installed in an exhaust system.

(Prior Art) Conventionally, a heat treatment apparatus has been used in a film forming process, a thermal diffusion process, etc. in the manufacturing process of semiconductor devices.

In such a heat treatment apparatus, a plurality of semiconductor wafers 1 are housed in a reaction vessel made of quartz or the like that can be maintained in a vacuum, and after the inside of the reaction vessel is evacuated to a predetermined reduced pressure state by a vacuum pump or the like, the pressure is reduced to a predetermined vacuum pressure. A reactive gas, an oxidizing gas, etc. are introduced while continuously purging the exhaust gas, and the temperature is raised to a predetermined reaction temperature so that the Si epitaxial growth film, oxide film, etc. are formed.

In addition, the gas exhausted from the above heat treatment equipment contains harmful substances such as unreacted film-forming gas and reaction products, and if these reach the vacuum pump such as the dry pump, the suction capacity will be reduced. As the conductance deteriorates and corrosion of various parts progresses, and as reaction products adhere to the piping system, the conductance decreases, so it is common practice to install a trap device in the middle of the exhaust route.

The above-mentioned trap device has, for example, cooling fins, etc., and cools the exhaust gas near the processing temperature within the trap device, causing reaction products in the exhaust gas to adhere to the above-mentioned cooling fins, etc. This is a device that captures and removes harmful substances by reacting or condensing unreacted substances in the gas and depositing them on cooling fins, etc.

(Problem to be Solved by the Invention) By the way, if a volatile component such as alcohol is contained in a captured substance such as a reaction product captured by the above-mentioned trap device, it will be volatilized from the captured substance. There was a problem in that the evacuation gas caused a reduction in the evacuation capacity of the vacuum pump.

For example, in the case of an exhaust system of a heat treatment apparatus as described above, this leads to a decrease in the degree of vacuum in the reaction vessel, which becomes a factor in the occurrence of processing defects.

In addition, normally in a trap device, if the amount of captured substances such as reaction products exceeds a certain amount, the removal efficiency of harmful substances from the exhaust gas will decrease and the exhaust capacity will decrease.
Remove the trap device from the exhaust system after a certain period of time,
The inside of the device is being cleaned. However, as mentioned above, if the evacuation capacity of the vacuum pump decreases due to volatile components, the cleaning period described above must be shortened, and the equipment downtime associated with cleaning increases, for example, reducing the operating efficiency of the heat treatment equipment. Safety is a concern due to the increased frequency of trap cleaning for harmful substances such as arsenic products.

The present invention has been made to address such problems, and an object of the present invention is to provide a trap device that suppresses a decrease in exhaust performance due to volatile components contained in trapped substances.

[Structure of the Invention] (Means for Solving the Problems) That is, the trap device of the present invention is detachably inserted into an exhaust system, and cools the gas flowing through the exhaust system, thereby trapping the gas in the gas. A trap device having a mechanism for capturing contained harmful substances is characterized in that the trapping mechanism has a mechanism for heating the captured substance.

(Function) In the trap device of the present invention, since a heating mechanism is added to the mechanism for capturing harmful substances by cooling, for example, when volatile components are included in the captured substance,
The heating mechanism described above can remove volatile components in the captured substance.

This removal of volatile components can be easily carried out without removing the trap device from the exhaust system, so it is possible to remove the volatile components without significantly reducing the operating efficiency of the device to which the trap device is connected, such as semiconductor manufacturing equipment. It becomes possible to suppress a decrease in system performance. In addition, by suppressing the reduction in exhaust capacity due to volatile components in the trapped substance, it becomes possible to extend the cleaning period of the trap device, thereby improving the operating efficiency of semiconductor manufacturing equipment and the like.

(Example) Hereinafter, an example of the apparatus of the present invention will be described with reference to the drawings.

As shown in FIGS. 1, 2, and 3, the trap device 1 of this embodiment has a water-cooling jacket 3 made of, for example, stainless steel, inside a cylindrical device body 2 that can be hermetically sealed. It is housed and configured.

In the apparatus main body 2, an exhaust gas introduction section 4 is installed at a position facing the water cooling jacket 3, and an exhaust gas introduction section 5 is installed in a direction perpendicular to the exhaust gas introduction section 4. That is, the water cooling jacket 3 is installed so as to obstruct the path of the exhaust gas sucked from the exhaust gas introduction section 4. The exhaust gas introduction section 4 and the exhaust gas outlet section 5 are removably connected to exhaust system piping (not shown) via a flange or the like.

The water cooling jacket 3 has a large number of cooling fins 6 that protrude in the direction of the suction path of the exhaust gas from the exhaust gas introduction section 4, and these cooling fins 6 are arranged so that the sucked exhaust gas and arranged to make contact.

Further, in the upper part of the water cooling jacket 3, a recess 7 with one end surface 7a open is provided. A heating heater 8 is housed in the recess 7 so as to be in contact with the upper surface 3a of the water cooling jacket 3 within the recess 7. This heating heater 8 penetrates through a lid part 2a which is removably installed on one end surface of the apparatus main body 2, and a part of it passes through the lid part 2a which is removably installed on one end surface of the apparatus main body 2.
being led outside.

Note that the cooling water inlet pipe 9 and outlet pipe 10 connected to the water cooling jacket 4 are also guided to the outside of the apparatus main body 2 through the lid portion 2a.

The trap device 1 having the above-described configuration is used by being inserted in the middle of the exhaust system 30 of the heat treatment device 20, as shown in FIG. 4, for example.

That is, the heat treatment apparatus 20 includes a cylindrical reaction vessel 22 in which a plurality of semiconductor wafers 21 as objects to be processed are accommodated.
and a heating heater 23 arranged to surround it.
A gas introduction pipe 24 for a reactive gas or the like is installed inside the reaction vessel 22. Furthermore, an exhaust system 30 is connected to the lower part of the reaction vessel 22, which is capable of evacuating the inside of the reaction vessel 22 to a predetermined reduced pressure state.

The exhaust system 30 is configured by connecting a vacuum pump 31 such as a dry pump to the reaction vessel 22 through an exhaust system piping 32. It is installed by 33, 34 etc.

Moreover, around the piping 32 on the upstream side of the trap device W1,
In order to prevent substances contained in the exhaust gas from adhering to the inside of the pipe 32 before reaching the trap device 1, a heating mechanism (not shown) is installed.

Next, a method of operating the trap device 1 having the above configuration will be explained.

First, for example, after a plurality of semiconductor wafers 21 are housed in the reaction vessel 22 which is in a preheated state, the inside of the reaction vessel 22 is evacuated to a predetermined reduced pressure state using the dry pump 31, and the temperature is raised to a predetermined processing temperature. , while continuing evacuation to maintain a predetermined degree of vacuum, a processing gas such as 5iH
2C12 and HCH3 are introduced into the reaction vessel 22 from the gas introduction pipe 24.
St epitaxial growth of the semiconductor wafer 21 and the like are performed by supplying the same to the semiconductor wafer 21.

During this exhaust treatment, the water cooling jacket 3 of the trap device 1
Cooling water is supplied to the system so that harmful substances in the exhaust gas can be captured.

As the process progresses, the exhaust gas introduced into the trap device 1 via the exhaust system piping 32 comes into contact with the water cooling jacket 3 and the cooling fins 6, whereby unreacted substances contained in the exhaust gas are reacted or condensed. The harmful substances in the exhaust gas are captured by the reaction products that adhere to the cooling fins 6 and the like, or the reaction products that are directly absorbed into the exhaust gas and the like adhere to the cooling fins 6 and the like.

If you repeat the above operations, water cooling jacket 3
Trapped substances such as reaction products are deposited on a large number of cooling fins 6 protruding from the cooling fins 6 . At this time, if the captured substance contains a volatile component such as alcohol, the evacuation capacity of the vacuum pump 31 will be reduced by the volatile gas from the captured substance.

Therefore, after a predetermined treatment period has elapsed, the heat treatment apparatus 20
During the processing stop period, volatile components in the captured substances are heated and removed.

In this heating removal process, first, the supply of cooling water to the water cooling jacket 3 is stopped, and the cooling water remaining in the water cooling jacket B is removed from the water cooling jacket 3. This cooling water removal can be easily carried out by, for example, connecting a pressurized gas supply pipe or the like to the cooling water introduction pipe 9.

Next, while operating the vacuum pump 31 to perform exhaustion, the heater 8 is operated. The heating temperature by the heating heater 8 is appropriately selected depending on the volatile component of interest. For example, when removing alcohol by heating, the amount of power supplied to the heater 8 is adjusted so that the temperature of the captured substance is about 100°C to IRQ°C. In addition, the volatile components to be heated are not limited to alcohols and the like, and organic metal compounds that serve as raw materials such as arsenic can also be removed by heating. In this case, 250
Heat to about 300°C to 300°C.

By operating the heater 8 in this manner and heating the captured substance, volatile components are volatilized and removed from the captured substance, and the exhaust capacity of the vacuum pump 31 is normalized.

The above heating removal process for volatile components can be performed without removing the trap device 1 from the exhaust system piping 32, and therefore can be performed safely and easily in a short time.

Note that the heat removal process described above cannot remove the solid captured substances themselves, so if the trapping efficiency of harmful substances decreases or the exhaust capacity basically decreases, the trap device 1 from the exhaust system piping 32 and transported to a safe location, the lid body 2a is opened, the captured substances adhering to the water cooling jacket 3 and the cooling fins 6 are disposed of, and the interior is cleaned.

In this way, in the trap device 1 of the above embodiment,
Since the heating heater 8 is installed on the water-cooling jacket 3, volatile components such as alcohol may be included in the substances that are attached to and captured on the water-cooling jacket 3, the cooling fins 6, etc. In some cases, volatile components can be easily removed. Furthermore, since this heat removal treatment of volatile components can be performed in a short time, there is little decrease in the operating rate of the heat treatment apparatus.

By heating and removing volatile components in this way, the reduction in performance of the exhaust system due to volatile components is suppressed, so the cleaning period of the trap device can be set based only on the amount of solid trapped substances. , the cleaning period can be significantly extended compared to the case where volatile components are included. Therefore, the stoppage time of the heat treatment apparatus due to cleaning of the trap device is shortened, the operation rate of the heat treatment apparatus can be improved, and safety can be improved.

Further, since the capacity of the exhaust system can be kept constant, it is possible to prevent processing defects of semiconductor wafers and the like.

In the above embodiment, an example was described in which the present invention was applied to a trap device inserted in the exhaust system of a batch-type heat treatment apparatus, but the present invention is not limited to this. The present invention can also be applied to a trap device inserted into the exhaust system of a resist coating device, etc., and the same effects as in the above embodiment can be obtained.

[Effects of the Invention] As explained above, according to the trap device of the present invention,
Since the volatile components contained in the captured substance can be easily removed in a short time, it is possible to suppress a decrease in the performance of the exhaust system caused by the volatile components. Therefore, it is possible to stably maintain the processing quality of semiconductor manufacturing equipment or the like to which the trap device is connected, and it is also possible to prevent a decrease in operating efficiency due to cleaning of the trap device.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the trap device of the present invention, FIG. 2 is a longitudinal cross-sectional view in the front direction of the trap device shown in FIG. 1, and FIG. 3 is a side view of the trap device shown in FIG. 1. FIG. 4 is a vertical cross-sectional view showing an example of the use of the trap device shown in FIG. 1. 1... Trap device, 2... Device main body,
3... Cooling jacket, 4... Exhaust gas inlet, 5... Exhaust gas outlet, 6...
・Cooling fin, 7...Recess for storing heater, 8・
... Heater for heating, 9 ... Cooling water inlet pipe, 10 ... Cooling water outlet pipe, 20 ... Heat treatment device, 30 ... Exhaust system. Diagram

Claims (1)

[Scope of Claims] A trap device that is detachably inserted into an exhaust system and has a mechanism for capturing harmful substances contained in the gas by cooling the gas flowing in the exhaust system, comprising: A trap device characterized in that the mechanism has a mechanism for heating the trapped substance.