JP2012143741A - Exhaust gas adsorbent and exhaust gas treatment method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust gas adsorbent and an exhaust gas treatment method using the same.SOLUTION: This exhaust gas adsorbent for a semiconductor etching process contains a laminar compound, an adsorption active component, and an inorganic moisturizing agent. The adsorption active component consists of one or more kinds of compounds selected from the group consisting of an alkali metal compound, an alkaline-earth metal compound, and an iron oxide compound. The exhaust gas treatment method can utilize the exhaust gas adsorbent.

Description

  The present invention relates to an exhaust gas adsorbent and an exhaust gas treatment method using the same. More specifically, an exhaust gas adsorbent capable of exhibiting excellent adsorption capacity and improving product life and the like, and exhaust gas treatment using the exhaust gas discharged through the etching process during the semiconductor manufacturing process Regarding the method.

  The lithography process is an indispensable process in the manufacture of semiconductor elements, and is broadly divided into a photoresist pattern forming process for applying a photoresist, exposing and developing, and an etching process using the photoresist pattern as a mask. . The etching process is roughly divided into a wet etching process and a dry etching process.

In the dry etching process, chlorine gas (Cl ₂ ), boron trichloride (BCl ₃ ), hydrofluoric acid (HF), fluorine gas (F ₂ ), sulfur hexafluoride (SF ₆ ), silicon tetrachloride (SiCl ₄ ), four Halogen group compound gases such as silicon fluoride (SiF ₄ ), hydrochloric acid (HCl), carbon tetrafluoride (CF ₄ ), tungsten hexachloride (WCl ₆ ), and hydrogen bromide (HBr) are often used.

  However, halogen compound exhaust gas after the etching process reacts easily when in contact with air, generates high reaction heat, and has the risk of fire and explosion, as well as fog, rain, etc. May react to cause acid rain. In particular, chlorine gas is extremely toxic and corrosive, and when the content in the air is 30 to 60 ppm, it stimulates eyes and bronchi violently and causes fatal diseases such as pulmonary edema. It is a very harmful substance for the human body. For this reason, many countries in the world have very strict regulations on their usage values. As an example, in the case of Korea, the TLV (Threshold Limit Value) representing the allowable concentration is limited to 1 ppm or less.

  Therefore, in order to treat the exhaust gas discharged in the etching process during the semiconductor manufacturing process, in the actual semiconductor manufacturing process, a separate scrubber is installed in the subsequent process of the etching process, and the exhaust gas discharged after the etching process by the scrubber is removed. Treated before being released into the atmosphere. Scrubbers are roughly classified into wet scrubbers and dry scrubbers.

  A wet scrubber is an apparatus that has been widely used in the past. However, when a wet scrubber is used in an etching process, a solid substance may be formed inside the scrubber to block the exhaust gas outlet. As a result, there is a drawback that substances such as aromatic chlorine compounds remain unreacted.

  On the other hand, dry scrubbers are devices that have been widely used in recent years in etching processes that mainly use halogen group compounds. A dry scrubber is an apparatus that attaches an exhaust gas adsorbent in a scrubber and removes exhaust gas generated during the etching process through physical and chemical adsorption reactions and decomposition reactions.

  However, in the conventional scrubber, in the actual semiconductor manufacturing process, the strength decreases due to the neutralization reaction, and the gap between the adsorbents decreases due to the solidification phenomenon in which some agglomeration occurs between the adsorbents due to the chemical reaction, There is a problem that the differential pressure becomes large by obstructing the flow of the fluid. Moreover, activated carbon or the like used as a typical adsorbent in conventional scrubbers may generate heat during a specific reaction, causing danger. Thus, the conventional scrubber has a lot of room for improvement in terms of stability, adsorption capacity and product life.

  As a result, in this technical field, it is necessary to study an exhaust gas adsorbent for a semiconductor etching process and an exhaust gas treatment method using the same, which is stable but has excellent adsorption ability and can improve the product life. Has been.

  In view of the above circumstances, an object of the present invention is to provide an exhaust gas adsorbent for a semiconductor etching process that has excellent adsorption ability and can improve the product life, and an exhaust gas treatment method using the same.

  The present invention is an exhaust gas adsorbent for a semiconductor etching process comprising a layered compound, an adsorption active component, and an inorganic humectant, wherein the adsorption active component comprises an alkali metal compound, an alkaline earth metal compound, and an iron oxide compound It consists of 1 or more types of compounds selected from the group which consists of.

  Moreover, the exhaust gas treatment method for a semiconductor etching process of the present invention is characterized by using the exhaust gas adsorbent for the semiconductor etching process.

  The present invention is an exhaust gas adsorbent for a semiconductor etching process comprising a layered compound, an adsorption active component, and an inorganic humectant, wherein the adsorption active component comprises an alkali metal compound, an alkaline earth metal compound, and an iron oxide compound. By using one or more compounds selected from the group consisting of the above, it is possible to improve the adsorption capacity for the exhaust gas generated in the semiconductor etching process and improve the product life as an exhaust gas adsorbent.

The photograph of the exhaust gas adsorbent of an embodiment of the present invention (3 mm diameter pellet).

  Hereinafter, the embodiment of the present invention will be described in more detail.

  The exhaust gas adsorbent of this embodiment includes a layered compound, an adsorption active component, and an inorganic humectant, and the adsorption active component is selected from the group consisting of an alkali metal compound, an alkaline earth metal compound, and an iron oxide compound. Consisting of one or more compounds.

  In the exhaust gas adsorbent of this embodiment, the layered compound acts to improve the performance by securing pores in the exhaust gas adsorbent and increasing the reaction area of the adsorbing active component.

  The layered compound is preferably selected from the group consisting of bentonite, hydrotalcite, montmorillonite, and vermiculite.

The layered compound preferably has a density in the range of 500 to 2000 kg / m ³ and a specific surface area in the range of 900 to 1400 m ² / g. When the layered compound has the density and specific surface area within the above range, the reaction area of the adsorption active component in the exhaust gas adsorbent can be increased.

  Moreover, it is desirable that the layered compound is contained in a range of 6 to 15% by weight with respect to the total weight of the layered compound, the adsorption active component, and the inorganic humectant. When the content of the layered compound is less than 6% by weight with respect to the total weight of the layered compound, the adsorptive active component and the inorganic moisturizing agent, sufficient adsorptive capacity cannot be obtained, and 15% by weight. When the amount exceeds 50%, a molding problem may occur, or the ratio of other active ingredients may decrease, resulting in a problem that the adsorptivity may be reduced.

  The layered compound can be in powder or granule form depending on the use and method of the exhaust gas adsorbent that is finally produced. The size of the layered compound is appropriately selected depending on the intended use and application object of the exhaust gas adsorbent. In the case of a powder form, the diameter is 1.2 mm or less, and in the case of a granule form, the diameter is 1 It is desirable that it is 2 mm or more.

  In the exhaust gas adsorbent of the present embodiment, the adsorption active component can minimize the heat of adsorption generated during the adsorption reaction. Moreover, since the said adsorption active component is excellent in the reactivity with a halogen group element resulting from the difference in electronegativity with a halogen group element, it can raise acidity and can increase adsorption activity.

  The adsorptive active component desirably contains one or more selected from the group consisting of alkali metal compounds, alkaline earth metal compounds, and iron oxide compounds.

Examples of the alkali metal compound include NaOH and KOH. Examples of the alkaline earth metal compound include Mg (OH) ₂ , Ca (OH) ₂ , and Sr (OH) ₂ . Examples of the iron oxide compound include FeO, FeO (OH), Fe ₂ O ₃ , and Fe ₃ O ₄ .

  As the adsorption active component, an alkali metal compound, an alkaline earth metal compound, or an iron oxide compound may be used alone, or two or more kinds may be used in combination.

In particular, it is desirable that the adsorption active component contains NaOH, Ca (OH) ₂ and FeO (OH).

  The exhaust gas adsorbent of this embodiment desirably contains the adsorption active component in a range of 80 to 90% by weight with respect to the total weight of the layered compound, the adsorption active component, and the inorganic moisturizing agent. If the content of the adsorptive active component is less than 80% by weight with respect to the total weight of the layered compound, the adsorbing active component and the inorganic humectant, sufficient adsorbing ability cannot be obtained, and 90 When the weight percentage is exceeded, a molding problem may occur, or the ratio of other active ingredients may be reduced, resulting in a problem that the adsorptive capacity is lowered.

  In the exhaust gas adsorbent of this embodiment, the inorganic humectant acts to retain appropriate moisture during the production of the exhaust gas adsorbent, and effectively widens the reaction area between the layered compound and the adsorption active component. Can do. Therefore, when removing gas, it contributes to the regulation of moisture generated during the neutralization reaction, and the chemical reaction causes some agglomeration between the adsorbents, reducing the gaps between the adsorbents and reducing the flow of fluid. This reduces problems such as an increase in differential pressure caused by obstruction and the occurrence of drift. In addition, the inorganic moisturizing agent is included in the exhaust gas adsorbent, so that the chemical adsorption, physical adsorption, decomposition reaction, etc. can be promoted during the exhaust gas treatment for the semiconductor etching process to improve the performance.

  The inorganic humectant is desirably one or more compounds selected from the group consisting of tetraethyl orthosilicate, zirconium propoxide, or titanium t-butoxide.

  The exhaust gas adsorbent of this embodiment desirably contains the inorganic humectant in a range of 1 to 6% by weight with respect to the total weight of the layered compound, the adsorption active component, and the inorganic humectant. When the content of the inorganic humectant is less than 1% by weight with respect to the total weight of the layered compound, the adsorption active component, and the inorganic humectant, sufficient adsorbability cannot be obtained. When the weight percentage is exceeded, a molding problem may occur or the adsorption capacity of the exhaust gas adsorbent may be lowered.

  Moreover, the exhaust gas adsorbent of this embodiment further includes a pigment or a dye, and may further include water.

  The pigment or dye is used to represent the color of the exhaust gas adsorbent, and an organic pigment, an inorganic pigment, a dye or the like is used alone or in combination, and its content is also appropriate so that the color of the exhaust gas adsorbent can be realized. There is no particular limitation as long as it can be determined.

  More specifically, examples of the organic pigment include C.I. I. Pigment Blue 15, C.I. I. A blue pigment such as Pigment Blue 15: 3; I. Pigment Violet 19, C.I. I. Violet pigments such as Pigment Violet 23; I. Pigment Green 7, C.I. I. Green pigments such as Pigment Green 10; C.I. I. Pigment Red5, C.I. I. Red pigments such as CI Pigment Red9; I. Pigment Orange 31, C.I. I. Orange pigments such as Pigment Orange 36; I. Pigment Yellow 13, C.I. I. Yellow pigments such as Pigment Yellow 42; I. Pigment Brown 23, C.I. I. A brown pigment such as Pigment Brown 25; I. And black pigments such as Pigment Black 7.

  Examples of the dye include azo dyes, phthalocyanine dyes, anthraquinone dyes, methine dyes, oxazine dyes, carbonium dyes, quinoneimine dyes, benzoquinone dyes, naphthoquinone dyes, triphenylmethane dyes, and indigoids. And dyes, perinone dyes, naphthalimide dyes, quinoline dyes, and metal complex dyes containing the dyes.

The exhaust gas adsorbent of this embodiment desirably has a specific gravity in the range of 0.6 to 0.8 g / cm ³ . By setting the exhaust gas adsorbent of the present embodiment to a specific gravity in the above range, it is possible to exhibit more excellent adsorbability and increase the product life.

  As described above, the exhaust gas adsorbent of the present embodiment includes a layered compound, one or more adsorbing active components selected from the group consisting of an alkali metal compound, an alkaline earth metal compound, and an iron oxide compound, and an inorganic moisturizing agent. By including the above, it is possible to exhibit a better adsorbing ability with respect to the exhaust gas generated during the semiconductor etching process and to increase the product life.

In the exhaust gas adsorbent of the present embodiment, the exhaust gas generated during the semiconductor etching process may include, for example, one or more of Cl ₂ , BCl ₃ , and HBr.

  The exhaust gas adsorbent of the present embodiment can be produced using a method usually used in the technical field, excluding the layered compound, the adsorption active component, and the inorganic humectant.

  The present invention also provides an exhaust gas treatment method for a semiconductor etching process using the exhaust gas adsorbent of the present embodiment.

  As the exhaust gas treatment method for the semiconductor etching process, a method well known in the technical field can be used except that the exhaust gas adsorbent of the present embodiment is used.

  Hereinafter, examples and comparative examples of the present invention will be shown. However, the following examples are provided for easier understanding of the present invention, and the contents of the present invention are not limited thereby.

<Example 1>
250 g of calcium hydroxide in the form of powder having a particle size of 325 mesh (density: 0.31 g / cm ³ , specific surface area: 26 m ² / g); I. 42.5 g of Pigment Yellow, 30 g of vermiculite, 10 g of tetraethyl orthosilicate, and 5 g of 93% NaOH for reagent were added to 80 g of water and kneaded. The obtained kneaded product was molded with an extruder under conditions of 5 ° C. and 60 rpm, and then dried while circulating air at 120 ° C. for 6 hours and at 180 ° C. for 6 hours. did. The strength of the exhaust gas adsorbent produced in this example was measured. The results are shown in Table 1.

<Example 2>
In this example, an exhaust gas adsorbent was manufactured in exactly the same manner as in Example 1 except that hydrotalcite was used instead of vermiculite. The strength of the exhaust gas adsorbent produced in this example was measured. The results are shown in Table 1.

<Example 3>
In this example, an exhaust gas adsorbent was produced in exactly the same manner as in Example 1 except that zirconium propoxide was used instead of tetraethyl orthosilicate. The strength of the exhaust gas adsorbent produced in this example was measured. The results are shown in Table 1.

<Example 4>
In this example, an exhaust gas adsorbent was produced in exactly the same manner as in Example 1 except that FeO (OH) was used instead of calcium hydroxide. The strength of the exhaust gas adsorbent produced in this example was measured. The results are shown in Table 1.

<Comparative Example 1>
In this comparative example, an exhaust gas adsorbent was produced in exactly the same manner as in Example 1 except that vermiculite was not used. The strength of the exhaust gas adsorbent produced in this comparative example was measured. The results are shown in Table 1.

<Comparative example 2>
In this comparative example, an exhaust gas adsorbent was manufactured in exactly the same manner as in Example 1 except that tetraethyl orthosilicate was not used. The strength of the exhaust gas adsorbent produced in this comparative example was measured. The results are shown in Table 1.

<Comparative Example 3>
In this comparative example, an exhaust gas adsorbent was produced in exactly the same manner as in Example 1 except that vermiculite and tetraethyl orthosilicate were not used. The strength of the exhaust gas adsorbent produced in this comparative example was measured. The results are shown in Table 1.

<Comparative example 4>
An insulator activated carbon (trade name: SGA-100, manufactured by Michisato Activated Carbon Co., Ltd.) was used as an exhaust gas adsorbent, and its strength was measured. The results are shown in Table 1.

<Experimental example>
The adsorption capacity of each exhaust gas adsorbent produced in Examples 1 to 4 and Comparative Examples 1 to 4 was evaluated using an adsorption experimental apparatus. As the adsorption experimental apparatus, an in-house experimental apparatus was used. This is a control equipment for a system that safely supplies special gas filled in a high-pressure gas container to the adsorption column at normal temperature and normal pressure. It is a touch screen system that can be controlled while viewing the screen. . As the exhaust gas for the semiconductor etching process, Cl ₂ , BCl ₃ , HBr or the like was used, and N ₂ gas was flowed together so that the flow rate of the gas passing through the packed bed was 1,000 ml / min. The adsorption column is filled with 100 ml of the exhaust gas adsorbent produced in Examples 1 to 4 and Comparative Examples 1 to 4, and the amount of removed gas is analyzed under the conditions of 20 ° C. and atmospheric pressure. It was evaluated by doing. The evaluation results are shown in Table 2.

  From the results of Table 1 and Table 2, the exhaust gas adsorbents of Examples 1 to 4 are stable against exhaust gas generated during the semiconductor etching process by including a layered compound, an adsorption active component, and an inorganic moisturizing agent. It is clear that it can exhibit excellent adsorption ability and improve product life.

  In particular, as shown in Example 1, it was confirmed that by using and selecting vermiculite, calcium hydroxide, and tetraethyl orthosilicate, a very high adsorbing ability can be obtained.

The present invention is applicable to a technical field related to an exhaust gas adsorbent and an exhaust gas treatment method using the same.

Claims (10)

An exhaust gas adsorbent for a semiconductor etching process comprising a layered compound, an adsorption active component, and an inorganic humectant,
The exhaust gas adsorbent for a semiconductor etching process, wherein the adsorption active component comprises one or more compounds selected from the group consisting of an alkali metal compound, an alkaline earth metal compound, and an iron oxide compound. In the exhaust gas adsorbent for the semiconductor etching process according to claim 1,
The exhaust gas adsorbent for a semiconductor etching process, wherein the layered compound is selected from the group consisting of bentonite, hydrotalcite, montmorillonite, and vermiculite. In the exhaust gas adsorbent for the semiconductor etching process according to claim 1 or 2,
The layered compound has a density in the range of 500 to 2000 kg / m ³ and a specific surface area in the range of 900 to 1400 m ² / g;
An exhaust gas adsorbent for a semiconductor etching process, comprising the layered compound in a range of 6 to 15% by weight with respect to a total weight of the layered compound, the adsorption active component, and the inorganic humectant. In the exhaust gas adsorbent for a semiconductor etching process according to any one of claims 1 to 3,
The selective adsorption active _{ingredient, NaOH, KOH, Mg (OH} ) 2, Ca (OH) 2, Sr (OH) 2, FeO, FeO (OH), Fe 2 O 3, and from the group consisting of _Fe 3 _{O 4} An exhaust gas adsorbent for a semiconductor etching process, comprising one or more of the above. In the exhaust gas adsorbent for a semiconductor etching process according to any one of claims 1 to 4,
An exhaust gas adsorbent for a semiconductor etching process, comprising the adsorbing active component in a range of 80 to 90 wt% with respect to a total weight of the layered compound, the adsorbing active component, and the inorganic humectant. In the exhaust gas adsorbent for a semiconductor etching process according to any one of claims 1 to 5,
The exhaust gas adsorbent for a semiconductor etching process, wherein the inorganic humectant is selected from tetraethyl orthosilicate, zirconium propoxide, titanium t-butoxide, and a mixture of two or more thereof. In the exhaust gas adsorbent for a semiconductor etching process according to any one of claims 1 to 6,
An exhaust gas adsorbent for a semiconductor etching process, comprising the inorganic humectant in a range of 1 to 6% by weight based on a total weight of the layered compound, the adsorption active component, and the inorganic humectant. In the exhaust gas adsorbent for a semiconductor etching process according to any one of claims 1 to 7,
The exhaust gas adsorbent for the semiconductor etching process further includes at least one selected from the group consisting of a pigment or a dye and water. In the exhaust gas adsorbent for a semiconductor etching process according to any one of claims 1 to 8,
An exhaust gas adsorbent for a semiconductor etching process, wherein the exhaust gas for the semiconductor etching process contains at least one selected from the group consisting of Cl ₂ , BCl ₃ , and HBr. An exhaust gas treatment method for a semiconductor etching process, wherein the exhaust gas adsorbent for the semiconductor etching process according to any one of claims 1 to 9 is used.