KR100444885B1 - Cleaning method of particles and moisture contained in the exhaust gas - Google Patents

Abstract

The present invention is a method of simultaneously removing the metal, metal oxides and water contained in the exhaust gas of the chemical vapor deposition, diffusion and ion implant process during the semiconductor manufacturing process using a porous functional filter It is about. The porous functional filter of the present invention has a porous form such as ceramic honeycomb, ceramic foam, and metallic foam, and is characterized by containing moisture adsorption components. By irregularly installing these porous functional filters in a separate pretreatment reactor or in the upper part of the adsorbent with respect to the gas flow direction, it is possible to effectively remove particulate matter and moisture by increasing the contact area and time between the filter and particulate matter and moisture. Therefore, it is possible to effectively prevent the pressure loss and the channeling phenomenon due to the formation of a solidification material that acts as a cause of frequent shutdown of the process. In addition, since the turbulence of the gas is caused by the porous functional filter, the residual gas may be evenly dispersed in the adsorbent layer to improve the adsorption performance of the adsorbent.

Description

Cleaning method of particles and moisture contained in the exhaust gas}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for removing particulate matter and water contained in semiconductor exhaust gas using a porous functional filter. Specifically, the chemical vapor deposition (DCVD), diffusion, and ions in a semiconductor manufacturing process. The present invention relates to an apparatus for effectively and effectively removing metals, metal oxides, and water contained in exhaust gases generated in an implant process using a porous functional filter.

In the semiconductor manufacturing process, gases that are toxic and corrosive to the human body, such as Cl ₂ , BCl ₃ , HF, F ₂ , BF ₃ , GeF ₄ , SiH ₄ , Si ₂ H ₆ , SiH ₂ Cl ₂ , NH ₃ , PH ₃ , AsH _3, etc. are used. Some of these toxic gases are consumed in the process and the remaining unreacted toxic gases are discharged to the outside. These unreacted toxic gases, if untreated and released into the atmosphere, have serious effects on humans and ecosystems.

Conventionally, a combustion process and a wet process are frequently used as toxic exhaust gas treatment methods generated in a semiconductor manufacturing process. The combustion process is a method of burning and removing toxic exhaust gas discharged at a high temperature of 800 ° C. or higher, and has a disadvantage of low removal efficiency and high annual operating cost. In addition, the wet process is a method of spraying and removing water on the toxic exhaust gas discharged, which has a low removal efficiency and wastewater, which is a secondary water pollutant, is generated and requires a separate wastewater treatment plant for its treatment. .

Therefore, recently, the adsorptive removal method using a dry scrubber, which is economical compared to the existing methods and in terms of suppression of secondary pollutants, is environmentally friendly and has high efficiency of removing toxic exhaust gases.

Exhaust gases emitted from CVD, diffusion, and ion implant processes during the semiconductor manufacturing process include particulate metals such as boron, silicon, arsenic, phosphorus, and B ₂ O ₃ , SiO ₂ , As ₂ O ₃ , As ₂ O ₅ , These metal oxides such as P ₂ O ₃ , P ₂ O ₅ , and water are contained. The particulate metal and / or metal oxide thereof is deposited on the adsorbent to prevent voids between the adsorbents, and the adsorbent and the particulate matter, the particulate matter and the particulate matter are aggregated with each other in the upper portion of the adsorbent by moisture to form a hard lump. It will form a solidifying material. In addition, the solidified material formed by the particulate matter and moisture not only causes a pressure loss, but also causes a channeling phenomenon in which the gas is concentrated in one direction by interfering with the flow of the exhaust gas, thereby lowering the adsorption function of the adsorbent. . As such, the pressure loss and the channeling phenomenon caused by the solidifying material act as a major cause of frequent shut-down of the process, which causes a lot of trouble in continuous operation.

Recently, in order to improve this problem, a ceramic ball-type filter having a larger particle size than an adsorbent is installed at the front of the adsorbent to remove particulate metals and metal oxides, but due to particulate matter and solid materials generated by moisture. The improvement effect on pressure loss and channeling phenomenon is not so large. That is, even in this case, the particulate matter easily accumulates in the voids between the ceramic balls and the balls, and the ceramic balls, the particulate matter, and the particulate matter and the particulate matter are entangled with each other to cause solidification, thereby causing pressure loss and channeling. On the other hand, in order to improve the above problems, when using a ceramic ball-type filter having a large particle size, the particulate material easily passes through the pores between the ceramic ball and the ball due to the bypass effect (by-pass effect), thereby adsorbent layer. The ceramic balls and the particulate matter, the adsorbent and the particulate matter, and the particulate matter and the particulate matter accumulate with each other and are solidified to cause pressure loss and channeling.

On the other hand, Japanese Patent Laid-Open No. Hei 1-317520 and U.S. Patent No. 6,099,808 disclose a technique for a pretreatment apparatus for removing particulate matter contained in exhaust gas using a fibrous filter. However, these methods are effective in removing particulate matter contained in the exhaust gas, but the removed particulate matter selectively blocks the pores of the fibrous filter and affects the flow of the exhaust gas, causing a pressure loss in a short time. This will cause frequent shutdowns of the process. In particular, US Pat. No. 6,099,808 provides a water elimination layer (Mist Eliminator) in front of the fibrous filter layer to prevent solidification due to aggregation of particulate matter in the fibrous filter layer by water, but clogging phenomenon of the filter layer by water. Has not effectively improved. Accordingly, the demand for a porous functional filter that can effectively prevent the pressure loss and channeling phenomenon caused by the solidified material by simultaneously removing the particulate matter and moisture contained in the exhaust gas.

Accordingly, the present inventors have completed the present invention after continuous research to solve the problems of the prior art described above.

SUMMARY OF THE INVENTION An object of the present invention is to provide a flue gas treatment apparatus capable of minimizing pressure loss and channeling caused by a solidified material by simultaneously removing particulate matter and moisture contained in flue gas generated in a semiconductor manufacturing process using a porous functional filter. It is.

Another object of the present invention is to provide a flue gas treatment method for simultaneously removing particulate matter and water contained in flue gas using a porous functional filter using the flue gas treatment device of the present invention.

1 shows an apparatus for removing particulate matter and water contained in exhaust gas discharged from a semiconductor manufacturing process.

Figure 2 shows a particulate matter and water removal apparatus contained in the exhaust gas according to another embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

1. Inlet 2. Porous functional filter

3. Pretreatment reactor 4. Tubing

5. Adsorbent 6. Dry Scrubber

7. Outlet

In order to achieve the above object, the exhaust gas treatment apparatus of the present invention includes an inlet (1) through which the exhaust gas is introduced;

A pretreatment reactor (3) connected to the inlet (1) and filled with a porous functional filter (2);

A dry scrubber 6 connected to the pretreatment reactor 3 and a pipe 4 and filled with an adsorbent 5 for toxic exhaust gas purification;

And an outlet 7 for discharging the treated gas (see FIG. 1).

Exhaust gas treatment apparatus as another embodiment of the present invention comprises an inlet (1) through which the exhaust gas flows;

A dry scrubber 6 connected to the inlet 1 and filled with a porous functional filter 2 in an upper layer and an adsorbent 5 in a lower layer;

And an outlet 7 for discharging the treated gas (see FIG. 2).

The porous functional filter may be a ceramic honeycomb, a ceramic foam, a metallic foam, and the like, and the exhaust gas may be randomly filled in the upper part of the adsorbent in a separate pretreatment reactor or a gas flow direction. By increasing the contact area and the contact time between the particulate matter and moisture contained in the functional filter and the contact time, the particulate matter and moisture can be effectively removed, and the turbulence of the gas flow is caused so that the residual gas is uniformly dispersed in the adsorbent layer. The adsorption function of the adsorbent can be improved.

In addition, the porous functional filter may be impregnated with at least one material capable of adsorbing moisture, for example, at least one of zeolite, clay, silica gel, alumina, silica-alumina, magnesium hydroxide, magnesia, calcium hydroxide, calcium oxide, or activated carbon. Alternatively, one or more washcoating or moisture-adsorbing materials may be mixed and extruded in a honeycomb form to remove particulate matter and moisture at the same time, effectively preventing the formation of solidifying materials that cause pressure loss and channeling. This can improve the continuous operation of the process.

Hereinafter, an operation according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Toxic exhaust gases containing metal particles, their metal oxides, and water, which are discharged from CVD, diffusion, and ion implant processes during the semiconductor manufacturing process, are pretreated with irregularly filled porous functional filters (2) through inlets (1). Pass through the reactor (3). At this time, the metal particles, their metal oxides and moisture contained in the toxic exhaust gas are removed through physical and chemical adsorption while passing through the porous functional filter (2), and a trace amount of metal, their metal oxides and water formed by bonding Material having a large particle size is lowered to the lower end of the pretreatment reactor 3 by gravity. On the other hand, the exhaust gas treated in the pretreatment reactor 3 passes through a dry scrubber 6 filled with an adsorbent 5 for removing toxic exhaust gas through a pipe 4, and the exhaust gas completely removed and purified is discharged through the outlet 7. Emissions to the atmosphere.

As described above, the porous functional filter of the present invention can simultaneously remove particulate metals, metal oxides, and moisture contained in the exhaust gas generated in the CVD, diffusion, and ion implant processes, thereby frequently shutting down the process. It is possible to effectively prevent the pressure loss and the channeling phenomenon caused by the formation of a solidifying material that acts as the main cause of the. In addition, by irregularly installing the porous functional filter of the present invention on the upper layer of the adsorbent, it is possible to effectively remove the particulate matter and moisture by increasing the contact area and time of the particulate matter and moisture contained in the exhaust gas and the functional filter. In addition, turbulence of the gas stream may be caused to cause the residual gas to be evenly dispersed in the adsorbent layer, thereby improving the adsorption function of the adsorbent.

In order to compare the effects of the present invention and the prior art was made a comparative experiment as follows.

Comparative Example

560 g of zeolite NaX (Aekyung Materials), 320 g of Bentonite (Duksan Pharmaceutical Co., Ltd.), and 920 g of distilled water were kneaded into a mixer and then kneaded using a vacuum extrusion machine (5 mm wide, 5 mm long, 7 mm long) 300 cpsi), which was dried at room temperature and calcined at 600 ° C. for 4 hours. 1.8L of the prepared zeolite-containing ceramic honeycomb was irregularly filled in the pretreatment reactor, and then the outlet of the pretreatment reactor was connected to the dry scrubber inlet filled with the adsorbent for removing toxic exhaust gas. And the pressure loss caused by the toxic flue gas containing the metal, metal oxide and water discharged from the ion implant process was measured. Then, if the difference between the inlet pressure and the outlet pressure is maintained for more than +50 mmH ₂ O for 5 seconds, install an interlock for detecting the inlet pressure abnormality of the exhaust gas, which causes the emergency lamp to turn on and makes a rich sound. The time required until the inflow of the pressure abnormality alarm was measured.

In addition, the ceramic ball (particle size: 5 to 8mm, Procatalyse) was installed in the pretreatment reactor in order to compare the effects of the present invention and the prior art, and the experiment was performed in the same manner as described above. The experimental results are shown in Table 1, and the porosity of the porous functional filter of the present invention was increased by more than 2 times, the surface area per filter volume was increased by 3.6 times, and the time required to generate an interlock alarm was delayed by 2.7 times. .

TABLE 1

Porosity Surface area per filter volume Time required until interlock alarm occurs (day) In the case of using the porous functional filter of the present invention 70% 3.8mm ² / mm ³ 184 days When using a ceramic ball filter 34% 0.86mm ² / mm ³ 69 days

In this case, the porosity and the surface area per filter volume were calculated by Equations 1 and 2, respectively.

Porosity (%) = (pore volume / filter volume) x 100%

Surface area per filter volume = surface area of filter / volume of filter

The present invention is to remove the particulate matter and water contained in the exhaust gas generated in the semiconductor manufacturing process as described above by using a porous functional filter at the same time to minimize the pressure loss and channeling phenomenon caused by the solidified material, the exhaust gas treatment apparatus It is a useful invention regarding.

Claims (12)

An inlet port 1 through which exhaust gas is introduced; A pretreatment reactor (3) connected to the inlet (1) and filled with a porous functional filter (2); A dry scrubber 6 connected to the pretreatment reactor 3 and a pipe 4 and filled with an adsorbent 5 for toxic exhaust gas purification; And an outlet (7) for discharging the treated gas. 2. The device according to claim 1, wherein the pretreatment reactor (3) is removed and the upper layer of the dry scrubber (6) is filled with a porous functional filter (2) and the lower layer is filled with an adsorbent (5). The device of claim 1 or 2, wherein the porous functional filter is selected from ceramic honeycomb, ceramic foam, and metallic foam. 4. The apparatus of claim 3, wherein the ceramic honeycomb, ceramic foam, and metallic foam have a partially cut or crushed form. The device according to claim 1 or 2, wherein the porous functional filter contains a moisture absorbent material. 6. The device of claim 5, wherein the moisture absorbent material is mechanically mixed with a porous functional filter and manufactured by extrusion molding in the form of a honeycomb. 6. The device of claim 5, wherein said moisture adsorbent material is selected from at least one of zeolite, clay, silica gel, alumina, silica-alumina, magnesium hydroxide, magnesia, calcium hydroxide, calcium oxide or activated carbon. The device of claim 1 or 2, wherein the porous functional filter is made by impregnating or washcoating one or more moisture adsorbent materials into a ceramic honeycomb, ceramic foam, or metallic foam. The apparatus for treating exhaust gas according to any one of claims 1 to 8 is used to enhance the contact removal area and time between particulate metals, their oxides, and moisture and functional filters contained in the exhaust gas discharged from the semiconductor manufacturing process. A method for treating flue gas, characterized in that it effectively removes particulate matter and moisture and turbulences the flow of flue gas to induce flue gas to flow uniformly into the adsorbent bed. 10. The method according to claim 9, characterized in that the trace particles having a large particle size formed by combining the particulate metals and their oxides with water are deposited by gravity to be lowered to the lower end of the pretreatment reactor (3). 10. The method of claim 9, wherein the semiconductor manufacturing process is a CVD, diffusion or ion implant process. 10. The method of claim 9, wherein the particulate metals and their oxides are boron, silicon, arsenic, phosphorus and B ₂ O ₃ , SiO ₂ , As ₂ O ₃ , As ₂ O ₅ , P ₂ O ₃ , P ₂ O ₅ Characterized in that the method.