JPH1161412A - Industrial pretreatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the adhesion of reaction products on the inside wall of piping and to enhance the removal efficiency of hazardous raw materials by adding a second scrubbing means to the position before a scrubber of the inside wall of the piping for introducing the gas for industrial pretreatment. SOLUTION: The gas G for industrial pretreatment introduced from a manifold 3 through an introducing pipe 4 into a tank 5 is scrubbed by a shower 8 which is disposed within the introducing pipe 4 and constitutes a scrubber 12. A shower 9 is also installed as a second scrubbing means into the manifold 3 existing in the upper part of the inlet of the introducing pipe 4. Fresh water is supplied to this shower 9 to scrub the gas G for industrial pretreatment in the inlet of the introducing pipe 4 and further the gas is scrubbed by the shower 8, by which all the inside walls 4a of the introducing pipe 4 may be made true regions to be scrubbed. The nozzle of a differential pressure gage 11 is projected from the inside wall of the introducing pipe 4 and the difference pressure is measured normally by directing the nozzle hole downward. The scrubbing efficiently by the showers 8, 9 is enhanced by controlling the flow rate of the gas G.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a scrubber for treating a gas to be removed containing a component to be removed, further pyrolyzing the gas containing the component to be removed after the treatment, For example, the present invention relates to an abatement apparatus configured to discharge gas of the type described above, for example, an abatement apparatus that performs an exhaust gas treatment in a plasma CVD facility.

[0002]

2. Description of the Related Art Conventionally, for forming a thin film on a wafer, a plasma CVD apparatus for forming a thin film by plasma discharge decomposition of a reactive gas under reduced pressure has been used. Various reaction products are generated depending on the components of the reactive gas.

[0003] As a method of treating a gas to be removed in exhaust gas in such a plasma CVD apparatus, a processing gas (SiH ₄ , NH ₃ , O ₂ , C ₂ F ₆ ) is thermally oxidized and decomposed with a scrubber. Although the removal process is performed by the reactor, the reaction product that cannot be removed and remains on the inner wall of the pipe adheres and accumulates, and the static pressure and the differential pressure gauge at the differential pressure gauge nozzle mounting portion are likely to fluctuate.

FIG. 3 shows an apparatus for removing a harmful gas contained in an exhaust gas from a plasma CVD apparatus (hereinafter, referred to as an apparatus).
It may be called a processing device. FIG.

As shown in FIG. 1, exhaust gas G discharged from a plurality of plasma CVD apparatuses is, for example, pipes 2a, 2b, 2
c, is collected in the collecting pipe 3,
And various processes for removing harmful substances contained in the exhaust gas G are performed until the exhaust gas G is discharged from the outlet 19 through the outlet pipe 6.

In this apparatus, the gas G introduced from the collecting pipe 3 into the tank 5 through the introducing pipe 4 is pure water sprayed from a shower 8 provided inside the introducing pipe 4 and constituting the scrubber 12. After being washed, some harmful substances are solidified or dissolved in water and fall into the tank 5. A valve 10 for adjusting the flow rate of the gas G passing through the inside of the processing apparatus 21 is provided in the inlet pipe 4 until the gas is collected from the plurality of plasma CVD apparatuses into the collecting pipe 3 and discharged from the discharge port 19. The outlet pipe 6 is provided with a valve 17. The differential pressure gauge 11 is located upstream of the valve 10 on the introduction pipe 4 side.
A nozzle 11a having a flat tip is positioned and installed in the introduction pipe 4, and constantly detects the gas flow rate, and controls the gas flow rate by a valve.

By the washing with the shower 8, gaseous harmful components contained in the exhaust gas G are dissolved or solidified in water and removed, and fall and accumulate in the tank 5, but the components not removed are gaseous. It starts to flow toward the outlet 19 through the upper part in the tank 5 as it is. However, the gas G containing the harmful components that have not been removed is heated by the heater 14 in the heat treatment unit 15 and thermally decomposed, and some of the components after the pyrolysis fall into the cleaning liquid in the tank 5 as solids. Further, a part of the gas goes to the discharge port 19 in a gaseous state. Therefore, the harmful substances are removed again by the shower 16 constituting the scrubber 18 provided in the outlet pipe 6 to remove the harmful substances, and the harmful substances are discharged from the discharge port 19 by the fan 7 as a gas containing no harmful components.

The tank 5 is separated into two tanks by a partition plate 5a, and the tank on the introduction pipe 4 side mainly stores the substance removed by the first washing by the shower 8, and the tank on the outlet pipe 6 side. The substance mainly removed by the secondary cleaning by the shower 16 is stored, and the cleaning water in the tank 5 is changed to pure water and circulated, and is again used for cleaning by the shower.

However, as shown in FIG. 3, the inner wall 4a of the introduction pipe 4 and the collecting pipe 3 upstream of the installation portion of the shower 8 are provided.
Reaction products 13 such as SiH ₄ and NH ₃ adhere to and accumulate on the inner wall 3a of the, and the pressure measured by the differential pressure gauge 11 fluctuates.
Further, as shown in FIG. 4, the tip tends to close the opening of the nozzle 11 a of the differential pressure gauge 11 located on the inner wall 4 a surface of the introduction pipe 4. For this reason, the differential pressure gauge does not operate sufficiently. For this reason, the valves 10 and 17 do not operate, the high-pressure gas G flows without adjusting the flow rate, and the efficiency of removing harmful substances by the showers 8 and 16 decreases.

[0010] When such a state occurs, the exhaust gas processing capability of the processing apparatus is reduced and the operation of the processing apparatus is automatically stopped.
Operation is forced to stop, the processing equipment is inspected and maintained, and a production loss occurs before returning to normal operation, thereby reducing production efficiency.

As described above, since one such processing apparatus is connected to a plurality of plasma CVD apparatuses, the operation of the plurality of connected plasma CVD apparatuses is stopped when one apparatus stops. Must stop, and
Products produced in this way may contain explosive substances, and there is even a danger of gas explosion due to clogging of piping and the like.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has been made to prevent the reaction products from adhering to the inner wall of a pipe and to improve the efficiency of removing harmful substances in exhaust gas. It is an object of the present invention to provide an abatement apparatus capable of increasing the operating rate of equipment.

[0013]

That is, according to the present invention, a gas to be removed containing a component to be removed is treated by a scrubber, and the gas containing the component to be removed after the treatment is further subjected to a thermal decomposition treatment. In the abatement apparatus configured to discharge the gas after the thermal decomposition treatment, in order to clean deposits adhered to an inner wall of a pipe for leading the abatement gas to the scrubber, a scrubber is disposed in front of the scrubber. The present invention relates to an abatement apparatus characterized by the addition of a second cleaning means.

According to the present invention, since the second cleaning means is further added in front of the cleaning means, the inner wall of the pipe is cleaned over a wide area to prevent deposition of deposits, and furthermore, in two steps. Harmful substances in the exhaust gas can be efficiently removed by the disposed cleaning means.

[0015]

In the abatement apparatus according to the present invention, it is preferable that the scrubber has a shower nozzle structure, and the cleaning means has a shower nozzle structure for supplying a fresh cleaning liquid.

In this case, it is preferable that the shower nozzle structure has a downward nozzle hole.

Further, a differential pressure gauge is provided between the scrubber and the cleaning means, and the differential pressure gauge has a nozzle structure in which a nozzle portion having a downward nozzle hole protrudes into the pipe. desirable.

Further, it is preferable that a flow rate measuring valve is provided in a pipe between the differential pressure gauge and the scrubber.

In the above detoxification apparatus, an inert gas such as nitrogen (N ₂ ) may be used as a cleaning medium instead of the cleaning liquid.

Hereinafter, preferred embodiments of the present invention will be described. In this embodiment, FIG. 3 and FIG.
The same reference numerals are used for the parts in common with.

FIG. 1 is a schematic diagram showing an embodiment of the abatement apparatus. As shown in the drawing, the basic configuration is the same as that of FIG. 3 described above, except that a shower 9 is added in the collecting pipe 3 and a nozzle 11 of the differential pressure gauge is protrudingly provided in the introducing pipe 4. That is.

Also in the apparatus of this embodiment, similarly to the case of FIG. 3 described above, the exhaust gas G connected to a plurality of plasma CVD apparatuses and discharged from each of the plasma CVD apparatuses passes through the pipes 2a, 2b, 2c. Via the collecting pipe 3. Then, various kinds of processing for removing harmful substances contained in the exhaust gas G are performed while being discharged from the discharge port 19 through the introduction pipe 4, the tank 5, and the discharge pipe 6.

In the apparatus of the present embodiment, since the shower 9 is provided as a second cleaning means in the collecting pipe 3 at the upper portion of the inlet of the introducing pipe 4, the liquid is introduced from the collecting pipe 3 to the tank 5 side. The gas G is washed by the shower 9 and the originally installed shower 8. Moreover, fresh water is supplied to the shower 9 to clean the gas G at the inlet of the introduction pipe 4, and together with the cleaning by the shower 8, all the inner walls 4 a of the introduction pipe 4 become the cleaning target area.

Since the reaction product does not adhere to the inner wall 4a of the introduction pipe due to this washing, the differential pressure gauge operates normally to detect the flow rate of the gas G, and based on the detection result, the valves 10, 17 are operated. The gas G that operates and is introduced from the collecting pipe 3
By controlling the flow rate, the cleaning efficiency by the showers 8 and 9 is increased. Moreover, as shown in FIG. 2, the nozzle 11a of the differential pressure gauge 11 is protruded from the inner wall of the introduction pipe 4, and the nozzle hole is directed downward, so that the cleaning water and the removed deposits do not enter.

By the two-stage cleaning by the showers 8 and 9, the harmful components contained in the gas G discharged from the plasma CVD apparatus are removed with higher efficiency than in the conventional example, and the water G is removed. It melts or solidifies and falls into the tank 5.

However, as described above, 2
The harmful substances remaining in the gas G without being removed even by the shower cleaning at the stage are thermally decomposed by heating in the heat treatment section 15 to be solidified and accumulated in the tank 5, but the remaining harmful substances are further removed from the discharge pipe. The gas is cleaned by the shower 16 in the chamber 6 and discharged as a clean gas from which harmful substances are completely removed.

As described above, in order to perform washing with the shower arranged in two stages in the area of the introduction pipe 4, the introduction pipe 4
Although the reaction product is prevented from adhering to the inner wall 4a,
As shown in FIG. 1, a small amount of deposit 13 is formed on a portion of the inner wall 3 a of the collecting pipe 3 where the action of the shower 9 does not reach, but this can be removed by regular maintenance of the facility, so that it does not hinder production efficiency. The time required for maintenance of the equipment was reduced from a total of 36 hours per month by conventional once-weekly maintenance to a total of 12 hours per month by twice-monthly maintenance.

According to the present embodiment, a new shower 9 is added above the inlet of the introduction pipe 4 in addition to the shower 8 at the existing position, and the shower 9 is introduced by washing using fresh water instead of pure water. The product can be sufficiently prevented from adhering to the inner wall 4a of the tube, and the washing efficiency of the inlet tube 4 can be increased.

Further, since harmful substances in the gas do not adhere to the inside of the pipe, the danger of explosion due to a chemical reaction of the product is eliminated and safety can be improved.

Further, since the time required for maintenance is shortened, the operation rate of the equipment is increased, and the productivity can be improved.

[0031]

As described above, according to the present invention, the second scrubber is provided in front of the scrubber in order to clean the deposits adhering to the inner wall of the pipe for introducing the gas to be scrubbed to the scrubber. Therefore, it is possible to prevent deposits from adhering to the inner wall of the pipe by cleaning a wide area of the inner wall of the pipe, and to remove the components to be removed from the harmful gas by a cleaning means such as a two-stage method. It can be removed with high efficiency. If this is applied to an exhaust gas processing apparatus of a plasma CVD apparatus, harmful substances in the exhaust gas can be efficiently removed, and the operation rate of the equipment can be increased to improve productivity.

[Brief description of the drawings]

FIG. 1 is a schematic view of an abatement apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged schematic sectional view of a differential pressure gauge nozzle mounting portion of the abatement apparatus.

FIG. 3 is a schematic view of a conventional abatement apparatus.

FIG. 4 is an enlarged schematic sectional view of a differential pressure gauge nozzle mounting portion of the abatement apparatus.

[Explanation of symbols]

1 ... abatement equipment, 2a, 2b, 2c ... piping, 3 ... collecting pipe,
3a, 4a ... inner wall, 4 ... introduction pipe, 5 ... tank, 5a ... partition plate, 6 ... outlet pipe, 7 ... fan, 8, 9, 16 ... shower, 10, 17 ... valve, 11 ... differential pressure gauge, 11a ... Nozzles, 12, 18 ... Scrubbers, 13 ... Deposits, 14 ... Heaters, 15 ... Heat treatment units, 19 ... Outlets, G ... Exhaust gas

Claims (6)

[Claims] An abatement gas containing a component to be removed is treated by a scrubber, a gas containing the component to be removed after the treatment is further subjected to a thermal decomposition treatment, and the gas after the thermal decomposition treatment is discharged. In the abatement apparatus configured as described above, a second cleaning means is added in front of the scrubber in order to clean deposits adhered to an inner wall of a pipe for guiding the abatement gas to the scrubber. Abatement device characterized by the above-mentioned. 2. The abatement apparatus according to claim 1, wherein the scrubber has a shower nozzle structure, and the second cleaning means has a shower nozzle structure for supplying a fresh cleaning liquid. 3. The abatement device according to claim 2, wherein the shower nozzle structure has a downward nozzle hole. 4. The abatement apparatus according to claim 1, wherein a differential pressure gauge is provided between the scrubber and the second cleaning means. 5. The abatement apparatus according to claim 4, wherein the differential pressure gauge has a nozzle structure in which a nozzle portion having a downward nozzle hole protrudes into the pipe. 6. The abatement apparatus according to claim 4, wherein a flow control valve is provided in a pipe between the differential pressure gauge and the scrubber.