JP2000140538A - Powder capturizing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the inhibition of a clogging in the filter due to a solid component contained in an exhaust gas from a semiconductor manufacturing device by sequentially arranging a filter part made of Teflon and a gas discharge part above a gas introduction part in which a scraper with plural blades mounted radially is fitted in a freely rotatable way. SOLUTION: The exhaust gas side of a dry pump is connected to the gas introduction aperture 11 of a gas introduction part 10 and, at the same time, a storage tank 60 is connected to a solid discharge aperture 13 formed at the bottom face with the center funneled downward, through a valve 14. In addition, a scraper 12 having four blades arranged at an almost 90 deg. interval is housed in the gas introduction part 10. Further, the scraper 12 is attached, in a freely detachable manner, to the tip of a rotary shaft 40 passing through the center of a filter 21 obtained by sewing a Teflon yarn-woven fabric in a cylindrical shape, of a filter part 20. Finally, the upper end part of the rotary shaft 40 is connected to the rotary shaft 40 of a motor 50 arranged above a gas discharge part 20 through a rotating seal 41 and thus the gas treatment is performed while the scraper 12 is rotated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for solidifying and collecting components that are solidified at room temperature and contained in exhaust gas of a semiconductor manufacturing apparatus. The apparatus of the present invention is preferably used in a semiconductor manufacturing process which includes a process in which a trouble due to a precipitated solid such as etching or CVD may occur, but has to be dealt with by a general device having a problem. .

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, a powder component and / or a gas component which solidifies at room temperature (hereinafter, both are collectively referred to as a solid component) are generated in various processes. For example,
In the etching step of aluminum as a wiring material, etching using boron trichloride is performed. At this time, aluminum chloride and boric acid are generated as solid powder. Further, in a liquid crystal maker, ammonium fluorosilicate powder is generated in the CVD process. These solid components cannot be released to the environment as they are, but of course, the passages, particularly the pipes from the dry pump to the exhaust gas treatment device, are blocked, so that they need to be removed by some means. As one of the means, there is a simple and clear method of solidifying and precipitating solid components in pipes and periodically cleaning or replacing the pipes. In addition to the unavoidable decrease, there is a drawback that the work becomes complicated because careful attention must be paid to prevent intrusion of impurities (contamination) into the apparatus.

[0003] As another means for removing solid components, there is a method of cooling and precipitating by an appropriate means, and then collecting by a bag filter installed at an appropriate position. Need to solve the problem of filter clogging. As a method of preventing clogging of the bag filter, a mechanical vibration method and a reverse injection method are known, but in the case of exhaust gas treatment of a semiconductor manufacturing apparatus, it is difficult to apply the reverse injection method from the viewpoint of preventing contamination. In addition to the small size, the restriction of use in a clean room is added, and it is difficult to apply a general vibration imparting type filter used in the chemical industry.

[0004]

DISCLOSURE OF THE INVENTION The present invention relates to a method for solidifying a solid component and / or a gas component which solidifies at room temperature contained in exhaust gas of a semiconductor manufacturing apparatus, and a filter for solidifying and depositing powder. It is an object of the present invention to provide a device that enables collection with suppressed clogging.

[0005]

The inventors of the present invention have studied in detail the properties of various solids that have adhered to a filter and have caused a clogging trouble. As a result, it is known that the solids are generated from a semiconductor manufacturing apparatus. It has been found that the adhesive force of a general solid to a filter is extremely weak, especially when the filter material is Teflon, and can be wiped off by applying a small impact. In addition, the inventors have found a method of applying a shock to a filter, which is adapted to the specialty of a semiconductor manufacturing apparatus in which a source of a gas to be treated is generated, and completed the present invention. That is, the present invention relates to a gas inlet having a solid material outlet on the bottom surface to which an exhaust gas inlet from a semiconductor manufacturing apparatus and a solid matter outlet provided with an opening / closing valve on a side surface, a filter portion above the gas inlet portion, and a powder capturing portion above the gas inlet portion. An outer container composed of a gas discharge portion having a post-collection gas outlet, and runs up and down the center of the outer container, and the upper end is gripped by a rotary seal attached to the center of the gas discharge portion upper surface,
The lower part is a rotating shaft gripped by a pivot set between the gas introduction part and the filter part, and the upper part is opened to the upper part inserted into the filter part in the outer container, and the upper end part is fixed to the outer container wall. However, the lower end portion is fixed to the outer periphery of a disk rotatable around a rotation axis passing through the center portion, and is capable of rotating following the movement of the rotation axis. The blade for scraping off solids deposited on the inner wall surface of the gas introduction unit, which is attached to the position of the gas introduction unit, A motor for giving rotation,
The present invention relates to a powder collecting device including a storage tank installed below a gas introduction unit and connected to a gas introduction unit solid matter outlet opening / closing valve. Hereinafter, the present invention will be described.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a powder collecting apparatus according to the present invention will be described.
FIG. 1 shows an installation position in a semiconductor manufacturing process. Exhaust gas from a semiconductor manufacturing apparatus 1 such as an etching apparatus and a vapor deposition apparatus is sent to a powder collecting apparatus 3 of the present invention via a dry pump 2. The exhaust gas from which the solid components and the components that may be solidified have been removed by the powder collecting device is sent to the exhaust gas treatment device 4, where the harmful components in the gaseous state are removed and detoxified by appropriate means such as adsorption. Released into the atmosphere.

FIG. 2 shows an example of the configuration of a powder collecting apparatus according to the present invention. The powder collecting device includes a gas introduction unit 10, a filter unit 20.
An outer container having a substantially cylindrical shape including a gas discharge portion 30, a filter 21, a blade for scraping solids deposited in a gas introduction portion (hereinafter referred to as a scraper) 12 inserted in the outer container,
It comprises a rotating shaft 40 for transmitting rotation to the filter and the scraper, a motor 50 as a power source for rotating the rotating shaft, and a storage tank 60 as a receptacle for solid components discharged from the gas inlet.

[0008] The outer container is composed of a gas inlet, a filter and a gas outlet in order from the bottom, but the filter and the scraper blades are much more attached and detached than an integral type that cannot be separated as a whole. It is preferable to set the structure so that it can be separated and removed from each part because it is easy and the operation during internal inspection and cleaning after long-term use is easy.

In the gas introduction section located at the lowermost layer of the outer container 1
On the side wall 0, some of the components contained in the gas introduced from the gas inlet 11 are cooled and condensed and deposited, and the scraper 1
It is scraped off in 2. Since the scraped-off solidified deposits accumulate on the bottom of the gas introduction section together with the powder removed from the upper filter, the storage tank installed at the bottom of the gas introduction section via the opening / closing valve 14 is provided below. A solid discharge port 13 connected to 60 is provided so that the sediment can be extracted into a storage tank. In this case, the removal of the deposit can be easily performed by operating the valve, and there is no need to stop the apparatus. In addition, the structure in which the bottom of the gas introduction portion is narrowed toward the center facilitates discharge of the sediment to the storage tank.

[0010] A scraper set at the lower end of the rotating shaft is inserted into the gas inlet, but in order to improve the scraping effect, the shape of the scraper blade is not a simple rectangle,
It is preferable that the trapezoidal shape allows scanning of the surface of the tapered portion on the inner bottom surface of the gas introduction portion, and the distance between the blade end portion and the inner wall surface of the gas introduction portion is desirably 1 to 3 mm. In addition, since the scraper blade material is installed in the exhaust gas introduction section, depending on the type of gas to be treated, there is a possibility of contact with high-temperature gas, taking into consideration the low adhesion of deposited solids to the blade itself and the light weight Then, it is preferable to use Teflon.

The number of blades of the scraper is two or more, and there is no problem if the scraper is disposed at a position substantially equally dividing 360 degrees around the rotation axis.
It is preferable that the number of sheets is four. In addition, the rotation mode is linked to the rotation of the filter described later, and will be referred to at the point where the rotation mode of the filter is touched.

The gas inlet from the former pump 2 is structurally located on the side of the gas inlet, but the vertical position is set such that the center of the inlet is lower than the center of the side wall. By doing so, the cooling effect in the gas inlet can be increased.

[0013] The species and characteristics of the components contained in the gas to be treated,
Depending on the amount, it may be necessary to heat and keep the piping from the pump to the powder collecting device in order to prevent blockage in the passage.However, the temperature in this case depends on the component species that may solidify and precipitate. Will decide. For example, in the case of aluminum chloride generated in an aluminum wiring etching process, it is necessary to keep the temperature at about 180 ° C.

The gas after a part of the solidified component solidifies and precipitates in the gas introduction part is sent to the filter part. In the filter section, the gas stream is further cooled to solidify and precipitate almost all of the components contained in the gas stream that can be solidified at room temperature as powder, and the powder present in the gas stream is captured by the filter. Gather. In addition, the setting of the water cooling jacket 23 covering almost the entire surface on the outer side surface of the filter unit makes perfect cooling of the gas flow and complete collection of the solid component by the filter. When the piping from the pump to the gas inlet is kept at a high temperature, a favorable result is obtained.

As the filter, a woven fabric sewn in a cylindrical shape is used. The lower end of the filter is fixed to a peripheral edge of a circular rotary plate 22 fixed to a rotary shaft passing through the center by a suitable means such as a holding plate, and can be rotated in conjunction with the rotation of the rotary shaft. It has a simple structure. On the other hand, the upper end of the filter is fixed to the outer container by the same fixing means as that used for the lower end. That is, the bottom part is fixed to the rotating plate and the closed lower part is movable following the rotation axis, but the opening that opens upward is fixed and does not move, so the filter is twisted according to the rotation of the rotation axis. become. The filter is set upside down, that is, the lower end of the filter is fixed so as not to move, and the upper end is movable in conjunction with the rotation of the rotating shaft. Although the same effect can be obtained in terms of surface, it is very difficult to attach and detach the filter, and the above-described method in which the lower end is movable is a more preferable method.

The material of the filter is elongation which can cope with torsional stress applied periodically for a long period of time, excellent mechanical properties of strength, and high chemical stability to withstand contact with reactive gas. It is preferable to use a synthetic organic material such as polyamide, polyester, acryl, vinyl acetate, aramid, or Teflon because of having properties. In particular, the use of Teflon having a low solid component adhesion is preferable.

The distance between the filter surface and the inner wall surface of the outer container filter portion can be made extremely narrow because the lower part of the filter rotates and the portion has a cooling effect. It is not preferable to increase the width, and the width is set to 10 to 20 mm.

Regarding the rotation mode of the rotating shaft, the conditions are that a sufficient force is applied to the filter to remove the accumulated powder, and that the scraper scans the entire inner wall of the side surface of the gas introduction section during one rotation cycle. There is no particular limitation as long as the filter can be satisfied, but since only the lower end of the filter is movable, rotation imparts twist to the filter, and making the rotation angle too large requires an unnecessarily large filter. It is not preferable because it will give an objective load.
The most preferable rotation mode is, as shown in FIG. 4, a repetition of rotation of swinging approximately 90 ° in the forward and reverse directions with respect to a certain point. In this rotation mode, it is possible to scan the entire bottom and side surfaces inside the gas introduction section even with two blades, and also to apply a sufficient impact to remove the solid matter deposited on the filter without damaging the filter. It is possible to add periodically.

The characteristics and amount of the solid deposited in the gas inlet and the powder deposited on the filter naturally vary depending on the gas to be treated. In response to this, the cycle of applying rotation to the filter and the scraper is changed. In most cases, however, the rotation is applied every 30 minutes, that is, once every 30 minutes. Unless the time required for one rotation application is set to an extremely large value, a practical value may be set instead of a large factor affecting the effect. For example, a time setting of about 1 second may be set for each one movement of a certain size such as a 90 ° clockwise rotation.

The rotation force is applied to the rotating shaft by a motor 50 provided above the outside of the gas discharge unit, and a stepping motor whose forward and reverse rotation is variable is used as the motor.
By presetting a desired rotation mode in the motor control unit 51 in advance, it is possible to perform an automatic operation of the powder collecting apparatus other than the operation of extracting the deposit from the gas introduction unit.

The rotation of the stepping motor is transmitted to the lower end of the filter and the scraper via a rotary shaft. The rotary shaft has a rotary seal 41 mounted on the upper part of the upper part of the gas discharge part at the upper part, and a filter and a scraper on the lower part. The supporting member 42 is held between the supporting members 42 via a suitable sliding member, and the rattling due to the rotation is suppressed. In addition, it is preferable to use a magnetic seal having excellent sealing properties for the rotary seal.

The gas from which the solidified components have been removed in the filter section moves to a gas discharge section located above the filter section,
The gas is discharged from a discharge port 31 provided on the side surface of the gas discharge portion so as to be sent to the next step 4 such as removal of harmful gas components if necessary.

The powder collected by the filter and deposited on the outer surface of the filter is wiped off by a rotating motion periodically applied to the lower portion of the filter, and the gas is introduced together with the solids scraped off by the scraper from the inner wall surface of the gas inlet. It accumulates at the bottom of the tank and is periodically discharged from the lower outlet to the storage tank.

The size of the powder processing apparatus of the present invention is determined depending on the type and amount of the gas to be processed discharged from the semiconductor manufacturing apparatus.
0 mm x 600 mm height (main body without motor and discharged solid storage tank) is sufficient.

The powder collecting apparatus of the present invention is preferably used in a state where the entire apparatus including the motor and the storage tank is stored in a storage case. Not only can various instruments be mounted, but also the storage tank can be easily replaced by providing support for the main body to the storage case. Of course, there is also an advantage that the appearance is excellent.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an example in which the powder collecting apparatus of the present invention is used for treating exhaust gas from an Al etching apparatus will be described, and the effects of the present invention will be specifically shown. (1) Processing Apparatus The configuration of the used powder collecting apparatus is shown in FIG. 2, and the external appearance is shown in FIG. The outer container has an inner diameter of 1 for the gas introduction section and the filter section.
Stainless steel tubes each having an outer diameter of 114.3 mm, which is slightly smaller than the 33 mm gas exhaust portion, are used.

The gas inlet is provided with a gas inlet 11 such that the center thereof is located approximately 60 mm from the upper end of the side surface having a height of about 100 mm, and is connected to the exhaust gas side of the dry pump. Although not shown here, the piping between the gas inlet and the pump is kept at 180 ° C. to prevent clogging at the point, and a pressure sensor connected to an alarm is provided at the gas inlet. It is set, and it is possible to detect clogging and clogging after the powder collecting device. A solid outlet 13 having the same diameter as the gas inlet is provided at the tip of the bottom of the gas inlet having a structure in which the center portion is narrowed downward, and the storage tank 60 having a capacity of 4.8 liters is provided via a ball valve 14. Are linked. The scraper 12 located in the gas introduction part is configured by arranging four substantially trapezoidal Teflon blades having a thickness of 3 mm around the rotation axis at approximately 90 ° intervals, and the outer edges of the blades extend from the gas introduction part inner wall surface. About 1.5mm
It is designed to move from a distance.

The filter portion is distinguished from the gas introduction portion by a wheel-type shaft support 42 having a rotary shaft through-hole at the center, and the connection between the two portions is made by flange fastening with the shaft support interposed therebetween. By doing so, it is possible to easily attach and detach the scraper blade. In addition, the rotating shaft 40 is gripped at the lower part by this pivot support, and the upper part is gripped by a rotary seal 41 set on the upper surface of the gas discharge part, which will be described later, so that stable rotation without touching is possible.

The filter 21 is made of a woven cloth having a thickness of about 3 mm and an average opening of 25 μm, woven of Teflon yarn, and having a diameter of about 100 μm.
What was sewn into a cylinder having a length of about 285 mm and a length of about 285 mm was used. The upper part of the filter is located
Along the outer edge of the ear part inserted in the filter part, it is fixed so as not to move with a stainless steel band, the lower part is
A stainless steel band is also fixed to an edge provided upward along the circumference of the 94 mm-diameter rotating plate 22 fixed to the rotating shaft, so that the rotation of the rotating shaft 40 is transmitted. The distance between the outer wall surface of the filter and the inner wall surface of the outer container of the filter is about 17 mm. In addition, on the side of the filter part,
A jacket 23 is provided.

The gas discharge section 30 at the top of the main body is provided with a discharge port 31 on the side face, and is connected to an exhaust gas treatment apparatus for collecting gaseous chloride in the next step. Not only is the filter and gas exhaust part separable by flanges, but also the part below the flange provided around the lower side of the gas exhaust part is manufactured from a stainless steel tube one diameter smaller than the filter part In addition to the structure that can be inserted into the filter portion, the filter has a sufficient width in the height direction, and the upper end of the filter can be easily fixed to the outer periphery of the insertion portion. Also. A magnetic seal unit 41 is buried in the center of the upper surface of the gas discharge part, and enables the upper part of the rotary shaft to be gripped almost completely with gas leakage suppressed.

(2) Gas to be Processed The gas to be processed is an etching gas formed by mixing boron trichloride (about 0.5% by volume) -chlorine (about 1% by volume) -nitrogen to etch aluminum wiring. After the operation, the exhaust gas contains aluminum chloride as a solid and / or a component capable of solidification and precipitation at a flow rate of about 20 l / min.

(3) Operation of Apparatus FIG. 4 shows the rotation mode input to the motor control unit 51 together with the rotation speed and the rotation cycle to be applied to the scraper and the lower part of the filter. 90 ° clockwise (I)
→ Counterclockwise 180 ° (II) → Clockwise 90 ° (III)
Is applied approximately once every 30 minutes at an angular velocity of approximately 90 ° / sec.

(4) Result The above-mentioned apparatus was operated continuously for 6 months under the condition of (3), but no trouble occurred during this time.
No pressure increase by the pressure sensor was observed. The operation stop in this example is requested from the storage tank capacity, and if the storage tank capacity is increased, the operation can be performed for a longer period of time.

On the other hand, when the filter is not used, that is, in FIG. 1, when the pump and the exhaust gas treatment device are directly connected, the piping of the connection portion is closed after 30 days of operation, and it is necessary to stop the operation of the device. Was. The weight of the obstruction deposit was about 500 g. This is an experimental result that motivated the inventor to proceed to the development of the powder collecting apparatus of the present invention, as in the case of the filter method without vibration addition described below.

Further, when a simple gas cooler and filter were inserted between the pump and the exhaust gas treatment device, the operation was stopped after 60 days. Although this is due to clogging of the filter, this example corresponds to the insertion of a device equivalent to the powder collecting device of the present invention from which the scraper and the rotary shaft have been removed, between the pump and the exhaust gas treatment device.

[0036]

The powder collecting apparatus according to the present invention solidifies and precipitates solid substances contained in the exhaust gas from the semiconductor manufacturing apparatus and which causes blockage of the passage, and reliably collects the precipitates.
In addition, by adopting a structure that enables periodic removal of trapped substances in the filter, continuous operation of the apparatus for a long period of time has been enabled. The cause of contamination has also been greatly reduced. In addition, the employment of a simple mechanism makes the whole apparatus very compact and has the advantage of taking up less space in a small clean room. The value of this powder collecting apparatus in the semiconductor manufacturing field, which is said to be rice in industry, is great.

[Brief description of the drawings]

FIG. 1 is a view showing a set position of a powder collecting device of the present invention.

FIG. 2 is a diagram showing a configuration example of a powder collecting device of the present invention.

FIG. 3 is a view showing an overall image of an example of a powder collecting apparatus according to the present invention.

FIG. 4 is a view showing an example of a rotation mode of a rotating shaft in the powder collecting device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Outer container gas introduction part 11 Gas inlet 12 Scraper 13 Sediment discharge port 14 Opening / closing valve 20 Outer container filter part 21 Filter 22 Rotating plate 23 Water cooling jacket 30 Outer container gas discharge part 31 Gas exhaust port 40 Rotating shaft 41 Rotary seal 42 Shaft support 50 Motor 51 Motor control unit 60 Storage tank

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shizuo Tokuura 1-12-32 Nishihonmachi, Ube City, Yamaguchi Prefecture Ube Industries, Ltd. Chemical and Resin Business Division F-term (reference) 4D058 JA42 LA01 MA05 RA11 SA04 UA03 4D076 AA05 AA06 AA14 AA24 BC06 BD07 BE06 BE08 CB05 CD03 CD08 CD16 EA12Y EA14X EA14Y EA16Y EA26X FA03 FA11 HA12 5F004 AA16 BC02 5F045 BB20 EG08

Claims (2)

[Claims] 1. A gas inlet having a solid material outlet on the bottom surface on which an exhaust gas inlet from a semiconductor manufacturing apparatus and an on-off valve are mounted, a filter portion above the gas inlet portion, and a powder capturing portion above the gas inlet portion. An outer container composed of a gas discharge portion having a post-collection gas outlet, and runs up and down the center of the outer container, and the upper end is gripped by a rotary seal attached to the center of the gas discharge portion upper surface, The lower part is a rotating shaft gripped by a pivot set between the gas introduction part and the filter part, and the upper part is opened to the upper part inserted into the filter part in the outer container, and the upper end part is fixed to the outer container wall. However, the lower end portion is fixed to the outer periphery of a disk rotatable around a rotation axis passing through the center portion, and is capable of rotating following the movement of the rotation axis. Gas guide installed at the position of the gas introduction section A blade for scraping solids deposited on the inner wall of the unit, a motor installed above the gas discharge unit for rotating the rotation shaft inside the outer container via a rotary seal mounted on the upper surface of the gas discharge unit, and a motor below the gas inlet unit. A powder collection device comprising a storage tank installed and connected to a gas introduction unit solid matter outlet opening / closing valve. 2. The powder collecting device according to claim 1, wherein a water-cooling jacket is mounted on an outer side surface of the outer container filter portion.