KR100303148B1 - Burn type dry gas scrubber for manufacturing semiconductor having electrostatic type dust collecting system - Google Patents

Abstract

The present invention relates to a dry gas scrubber for manufacturing a semiconductor having an electrostatic dust collecting system which can easily process collected solid particles and improve dust collection efficiency. The scrubber of the present invention is for a process used in a semiconductor and LCD manufacturing process. A thermal reaction unit which heats and heats a gas inside the high temperature reaction chamber; A separation unit for collecting the solid particles generated during the thermal reaction and separating the particles from the gas; And a dust collecting part for collecting solid particles separated from the separating part, wherein the separating part is formed of a cylinder having a closed cross-sectional shape, and includes a separation chamber into which a process gas and solid particles are introduced, and a separation chamber having passed through the reaction chamber. An electrode rod which is installed inside and collects the solid fine particles on the inner circumferential surface of the cylinder, a scraper having the same cross-sectional shape as that of the separation chamber, and which is installed in the state of being in contact with the inner circumferential surface of the chamber, and which moves the scraper up and down It comprises a means for moving. Thereby, even when the solid fine particles collected on the inner circumferential surface of the separation chamber are viscous, the fine particles can be reliably removed, thereby preventing the collection efficiency from being lowered due to the solid fine particles being removed indefinitely.

Description

BURY TYPE DRY GAS SCRUBBER FOR MANUFACTURING SEMICONDUCTOR HAVING ELECTROSTATIC TYPE DUST COLLECTING SYSTEM}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry gas scrubber for manufacturing semiconductors, which purifies the remaining gaseous chemicals used in semiconductor and liquid crystal display device (LCD) manufacturing processes, and more particularly, to easily process collected solid particles and improve dust collection efficiency. The present invention relates to a dry gas scrubber for manufacturing a semiconductor having an electrostatic dust collection system.

In the manufacturing process of semiconductor and liquid crystal display devices, harmful gases such as silane (SiH ₄ ) and arsine (AsH ₃ ) and process gases such as hydrogen are used for the deposition, diffusion, and etching processes. Toxic, the used process gas should be purged and discharged into the atmosphere.

Therefore, a sub scrubber for supplying and purifying the process gas is installed in each line of the semiconductor manufacturing process, and each subscrubber is connected to one duct, which is mainly installed on the roof of a building. It is connected to the main scrubber.

Accordingly, the used process gas is firstly purified in the subscrubber, the firstly purified process gas is supplied to the main scrubber through the duct, and is secondly purified in the main scrubber and then discharged to the atmosphere.

As such, the subscrubber for primary purification of the process gas is generally classified into a wet scrubber and a dry scrubber depending on the treatment method.

The wet scrubber removes the exhaust gas by the adsorption method by passing the process gas through ultrapure water (H ₂ O) or gas adsorbent liquid chemical, or spraying it in a mist state, and thus has a relatively simple configuration. Although it has the advantage of easy and large capacity, it is not suitable for the treatment of gas containing hydrogen group with strong ignition, and when the liquid chemical is used as the main agent, it generates secondary pollutants. There is this.

In addition, the dry scrubber forms a high temperature chamber by using a heat source such as a heater, and passes the process gas into the chamber to solidify the gas by thermal reaction, which is relatively safe and easy to control temperature. Used.

The present invention relates to the dry scrubber, the scrubber is largely a thermal reaction unit for thermally reacting the process gas, a separation unit for collecting the solid particles generated during the thermal reaction to separate the fine particles and the gas, and the separated solid It can be divided into a dust collecting part collecting particulates.

Referring to FIG. 1, a conventional dry scrubber is described. The thermal reaction unit 110 for thermally reacting a process gas is installed to surround the reaction chamber 112 and the reaction chamber 112, thereby providing a chamber 112. It consists of a heater 114 for heating the interior to about 800 ℃ or more, the chamber 112 is a gas inlet 116 through which the process gas is introduced and the air inlet 118 through which the compressed air (CDA) is introduced And a nitrogen inlet 118 ′ through which nitrogen is introduced.

Here, the inside of the chamber 112 is heated to about 800 ° C. or more because most of the process gases are thermally reacted at or below the temperature.

The separating unit 120 that separates the solid fine particles (solid gas particles) and the gas is configured to collect solid fine particles having a certain electrical property by using an electrostatic effect. The separation chamber 122 And a plurality of dust collecting plates 124 installed in the separation chamber 122 at predetermined intervals and to which a predetermined voltage is applied, and removal means for removing solid particles collected on the surface of the dust collecting plate 124. The removal means is composed of an impact hammer 126 that impacts the dust collecting plate 124 while rotating in the direction of the arrow at regular time intervals or a vibrator (not shown) which vibrates the dust collecting plate 124 at regular time intervals.

Here, voltages of different potentials, for example, voltages of positive and negative potentials are alternately applied to the neighboring collector plates 124, and the same voltage is applied to the collector plates 124. The solid solid particles are collected on the surface of the dust collecting plate 124 due to the electrostatic effect.

In addition, the dust collecting unit 128 collecting the solid particles falling off the surface of the dust collecting plate 124 includes a dust collector 130, and the dust collector 130 is provided with an opening / closing cleaning tool 132 used to remove the solid particles. .

Accordingly, when the process gas, air, and nitrogen are supplied to the thermal reaction unit 110 through the inlets 116, 118, and 118 ′, the gas passes through the inside of the chamber 112 heated to a predetermined temperature by the heater 114. It causes a thermal reaction.

That is, when silane (SiH ₄ ) is described as an example in the process gas, the silane causes a reaction as in the following reaction formula (1).

SiH ₄ + O ₂ ⇒ SiO ₂ + 2H ₂ ------------------------------ (1)

The fine particles of silicon dioxide (SiO ₂ ) generated by the reaction pass through the space between the dust collecting plate 124, wherein the solid fine particles are collected on the surface of the dust collecting plate 124 due to the electrostatic effect and are collected. The solid particles thus collected are separated from the surface of the dust collecting plate 124 by the impact hammer 126 or the vibrator and are collected by the dust collector 130.

The gas separated from the solid particles is supplied to a duct (not shown) through the gas outlet 134 provided in the separation chamber 122, and then supplied to the main scrubber through the duct and collected in the dust collector 130. Particulates are periodically removed through the opening and closing cleaning tool 132.

By the way, the conventional scrubber comprised as mentioned above has the following problems.

That is, the conventional scrubber uses an impact hammer or a vibrator to remove the solid particles collected on the dust collecting plate, and thus, in the case of the solid particles having a viscosity, there is a limit in removing the particles by impact or vibration.

Therefore, solid fine particles that cannot be removed remain on the surface of the dust collecting plate, and thus there is a problem that the dust collecting efficiency is lowered.

Accordingly, an object of the present invention is to provide a dry gas scrubber for manufacturing a semiconductor having an electrostatic dust collecting system which can easily process collected solid particles and improve dust collection efficiency.

1 is a block diagram of a dry gas scrubber according to the prior art.

2 is a block diagram of a dry gas scrubber according to the present invention.

An object of the present invention as described above is to form a separation chamber into which the process gas after the thermal reaction flows into a cylindrical body having a closed curve cross section, and inside the cylinder an electrode rod for collecting solid fine particles on the inner peripheral surface of the cylindrical body, By a dry gas scrubber for semiconductor manufacturing having an electrostatic dust collecting system having a strip-shaped scraper which has the same cross-sectional shape as the cylinder and moves up and down in contact with the inner circumferential surface of the cylinder and removes solid particulates collected on the inner circumferential surface of the cylinder. Is achieved.

Thereby, even when the solid microparticles | fine-particles collected on the cylinder inner peripheral surface have viscosity, it can be reliably removed, and the dust collection efficiency can be improved by this.

Hereinafter, a dry scrubber according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The dry scrubber of the present invention collects a thermal reaction unit for heating and thermally reacting a process gas used in a semiconductor and an LCD manufacturing process in a high temperature reaction chamber, and solid particles generated during the thermal reaction. And a separating part for separating the fine particles from the gas, and a dust collecting part for collecting the solid fine particles separated from the separating part.

The thermal reaction unit 10 for thermally reacting the process gas includes a reaction chamber 12 and a heater 14 installed to surround the reaction chamber 12 to heat the inside of the chamber 12 to about 800 ° C. or more. The chamber 12 includes a gas inlet 16 through which process gas is introduced, an air inlet 18 through which compressed dry air (CDA) is introduced, and a nitrogen inlet 18 'through which nitrogen is introduced. .

The separator 20 for separating solid particles (solid gas particles) and gas is configured to collect solid particles having a certain electrical property by using an electrostatic effect. It is possible to move up and down along the direction of the arrow in contact with the cylindrical separation chamber 22 into which gas and solid fine particles flow, the electrode rod 24 provided inside the separation chamber 22, and the inner circumferential surface of the chamber 22. And a circular band-shaped scraper 26, and moving means such as a cylinder (not shown) for vertically moving the scraper.

Here, a voltage of negative (-) potential is applied to the electrode 24, and the solid particles having a certain electrical property are collected on the inner circumferential surface of the separation chamber 22 due to the voltage applied to the electrode 24.

In addition, the dust collector 28 in which the reaction chamber 12 and the separation chamber 22 are installed is provided with an opening / closing cleaning tool 30 used to remove the solid particles collected in the dust collector 28.

The scrubber of this invention which has such a structure is operated as follows.

Table 1 below shows some examples of process gases that can be treated in the scrubber of the present invention, and each process gas causes thermal reactions according to the reaction concentrations at respective thermal reaction temperatures shown in Table 1, and the hot plate Solid stares (solid gas particles) are produced at the gaze.

When a process gas, compressed air and nitrogen enter the reaction chamber 12 through the gas inlet 16, the air inlet 18 and the nitrogen inlet 18 ', the gas is heated by the heater 14 As shown in Table 1, thermal reactions occur, and the solid particles and gases generated during the thermal reaction of each gas flow into the separation chamber 22, whereby the electrode 24 installed inside the separation chamber 22 is negative. A voltage of negative potential is being applied.

Table 1

Name of gas Chemical formula Scheme Remarks (thermal reaction temperature) Silane SiH ₄ SiH ₄ + O ₂ SiO ₂ + 2H ₂ 300 ℃ Disilane Si ₂ H ₆ Si ₂ H ₆ +3 O ₂ 2SiO ₂ + 3H ₂ O 300 ℃ Dichlorsilane SiH ₂ Cl ₂ SiH ₂ Cl ₂ + O ₂ SiO ₂ + 2HCl 100 ℃ Phosphine PH ₃ 4PH ₃ + 8O ₂ 2P ₂ O ₅ + 6H ₂ O 375 ℃ Divoren B ₂ H ₆ B ₂ H ₆ + 3 O ₂ B ₂ O ₃ + 3 H ₂ O 40 ℃ Oxygen compound O ₂ (SiH ₄ ) O ₂ (SiH ₄ ) SiO ₂ + 2H ₂ 650 ℃ Nitric oxide compounds N ₂ O (SiH ₄ ) 2N ₂ O + SiH ₄ SiO ₂ + 2H ₂ + 2N ₂ 650 ℃ Ammonia Compound NH ₃ (SiH ₄ ) 4NH ₃ + 3SiH ₄ Si ₃ N ₄ + 12H ₂ 655 ℃ TEOS Si (OC ₂ H ₅ ) ₄ Si (OC ₂ H ₅ ) ₄ + 12O ₂ SiO ₂ + 8 CO ₂ + 10 H ₂ O 260 ℃ Arsine AsH ₃ 2AsH ₃ + 3O ₂ As ₂ O ₃ + 3 H ₂ O 300 ℃ Nitrogen tetrafluoride NF ₄ 2NF ₄ + 4H ₂ N ₂ + 8HF 200 ℃ Ethane hexafluoride C ₂ F ₆ C ₂ F ₆ + O ₂ 2CO ₂ + 3F ₂ 600 ℃ Sulfur tetrafluoride SF ₄ SF ₄ + O ₂ SO ₂ + 2F ₂ 600 ℃ Silicon tetrafluoride SiF ₄ SiF ₄ + O ₂ SiO ₂ + 2F ₂ 600 ℃ Hydrogen H ₂ 2H ₂ + O ₂ 2H ₂ O 100 ℃

Therefore, the solid fine particles exhibiting certain electrical properties are collected on the inner circumferential surface of the chamber 22 due to the electrostatic effect by the electrode rod 24 while passing through the chamber 22, and the solid fine particles collected on the inner circumferential surface of the chamber 22 are It is removed from the chamber 22 by the scraper 26 operating up and down in the direction of the arrow by a moving means such as a cylinder, and is collected in the dust collector 28, and the solid particles collected in the dust collector 28 are opened and closed cleaning tools ( Through 30).

The gas separated from the solid fine particles is supplied to a duct not shown through the gas outlet 32 of the separation chamber 22, and then to the main scrubber through the duct.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the range of.

As described above, according to the scrubber of the present invention, even when the solid fine particles collected on the inner circumferential surface of the separation chamber have a viscosity, the fine particles can be reliably removed.

Therefore, the dust collection efficiency can be prevented from being lowered due to the solid fine particles being removed indefinitely.

In addition, according to the conventional scrubber that removes the solid particles using a hammer or vibrator, there is a problem in that the working environment is not good because the noise generated by the operation of the members, but the scrubber of the present invention scrapes the solid particles using a scraper Since it is a structure that lowers the noise, there is no effect to improve the working environment.

Claims (1)

A thermal reaction unit which heats and heats a process gas used in a semiconductor and an LCD manufacturing process in a high temperature reaction chamber; A separation unit for collecting the solid particles generated during the thermal reaction and separating the particles from the gas; A dust collecting unit collecting solid particles separated in the separating unit; It includes, The separating portion is formed of a cylindrical body having a closed cross-sectional shape, the separation chamber into which the process gas flows through the reaction chamber, and the electric force of the repulsive force is installed in the separation chamber and the solid particles having a certain electrical properties An electrode rod for collecting the fine particles on the inner circumferential surface of the cylinder, a scraper having the same cross-sectional shape as the separation chamber and installed up and down in contact with the inner circumferential surface of the chamber, and moving the scraper up and down. A dry gas scrubber for manufacturing semiconductors having an electrostatic precipitating system comprising a moving means.