JP2005079138A - Draft chamber and cleaning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a draft chamber that can clean exhaust from a draft chamber body and has high energy efficiency, without discharging harmful gas inside a clean room. <P>SOLUTION: In the draft chamber having the draft chamber body, and a gas-liquid contacting apparatus connected to the exhaust section of the draft chamber body, the gas-liquid contacting apparatus uses an oblique honeycomb. A cleaning device comprises a turntable that uses the draft chamber and places an object to be treated in a treatment chamber for rotation, and a nozzle for supplying a chemical liquid to the object to be treated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a draft chamber and a cleaning apparatus using the draft chamber. More specifically, the present invention relates to a draft chamber used for chemical cleaning and etching of a silicon wafer or the like using a chemical solution in a semiconductor manufacturing process, and a cleaning apparatus using the draft chamber.

  In order to manufacture a semiconductor, a process of cleaning or etching a silicon wafer is required. These steps are usually performed in a draft chamber placed in a clean room to prevent contamination of the silicon wafer. Specific treatment methods such as cleaning and etching include, for example, a solution containing hydrogen peroxide, ammonia, hydrochloric acid, sulfuric acid, etc. heated at a high temperature, or a chemical solution containing hydrofluoric acid or nitric acid as a component. A method of processing a silicon wafer is mentioned.

  However, when harmful gases generated from the above solutions and chemicals leak into the clean room, the environment in the clean room is contaminated. For this reason, there is a need for a draft chamber that prevents harmful gases from leaking into the clean room.

As such a draft chamber, for example, in Japanese Patent Application Laid-Open No. 63-248449, a flow of air from the front to the rear is made above the liquid surface of the chemical tank provided in the draft chamber, and the flow is made from the chemical tank. A draft that prevents harmful gas from leaking into the clean room from the inside of the draft chamber by taking in the harmful gas that is generated, and that creates a flow of air downward from the ceiling of the chamber to prevent leakage of harmful gas into the clean room. A chamber is disclosed. According to this draft chamber, it is possible to efficiently discharge the harmful gas generated from the chemical tank with a small amount of exhaust air without discharging it to the clean room.
JP-A-63-248449 (Claims, FIG. 1)

  However, since the above-described draft chamber is not provided with an exhaust treatment device in the exhaust pipe, the exhaust is discharged outside the clean room, not inside the clean room. Then, since it is necessary to take in fresh air for the amount of discharged air from the outside of the clean room, electric power for cleanly processing the outside air is required, and energy efficiency is not good. Therefore, an object of the present invention is to provide a draft chamber with high energy efficiency that can clean exhaust gas from the draft chamber body without discharging harmful gas into the clean room.

  Under such circumstances, as a result of diligent study, the present inventor exhausts the exhaust to the outside of the clean room if a gas-liquid contact device for cleaning the exhaust from the draft chamber is disposed at the exhaust port of the draft chamber. The present invention has been completed by finding that all can be circulated and used in a draft chamber or a clean room.

  That is, the present invention provides a draft chamber comprising: a draft chamber main body; and a gas-liquid contact device that is connected to an exhaust portion of the draft chamber main body and purifies exhaust from the exhaust portion. is there.

  The present invention also includes a turntable that uses the draft chamber and that can rotate by placing an object to be processed in the processing chamber, and a nozzle that can supply a chemical to the object to be processed. A cleaning apparatus is provided.

  Since the draft chamber according to the present invention includes the draft chamber and the gas-liquid contact device, harmful gas in the air can be removed without being discharged outside the draft chamber or the clean room. In addition, since clean air from which harmful gases have been removed can be reused, it is no longer necessary to introduce new air into the clean room from the outside. No power is required.

  In addition, when a slanted honeycomb is used as a gas-liquid contact device, the harmful gas removal efficiency is higher than that of a conventionally used water shower. Therefore, the harmful gas in the air can be removed with a small removal device and a small amount of removed water. It can be removed without discharging outside or clean room. In addition, since the slanted honeycomb has a thin wall thickness, the pressure loss of the air is small, so that the electric power for moving the fan for conveying the air is small, which is advantageous in terms of running cost.

  Furthermore, since the draft chamber according to the present invention does not discharge harmful gas as described above, the space saving property of the apparatus can be improved by installing the draft chamber main body and the gas-liquid contact device in the clean room.

  In addition, the draft chamber according to the present invention includes a first air intake unit, and first air flow generating means for generating a first air flow from the upper side to the lower side in the processing chamber using air supplied from the first air intake unit. , The discharge of harmful gas inside the processing chamber to the outside of the draft chamber or to the clean room can be more effectively suppressed.

  In addition, the draft chamber according to the present invention includes a liquid tank in the processing chamber, and a front surface of the draft chamber main body above the liquid tank using a second intake portion and air supplied from the second intake portion. And a second air flow generating means for generating a substantially horizontal second air flow from the front side to the back side of the toxic gas generated in the processing chamber and above the liquid tank to the outside of the draft chamber or to the clean room. Emission can be suppressed more effectively.

  In addition, the draft chamber according to the present invention includes a plurality of liquid tanks in the processing chamber, and uses a second air intake unit and air supplied from the second air intake unit above the liquid tank. And a second air flow generating means for generating a substantially horizontal second air flow from the front side to the back side of the front side of the draft chamber body, harmful gas generated in the processing chamber and above the specific liquid tank The discharge to the outside of the draft chamber or to the clean room can be more effectively suppressed.

  The draft chamber according to the present invention includes a plurality of liquid tanks in the processing chamber and a carrier transport device for sequentially immersing carriers in the plurality of liquid tanks, and a carrier operation window on the front surface of the draft chamber body. And a rear side of the front side of the draft chamber body above the front surface of the main body of the draft chamber above the liquid level of the chemical tank that generates at least a toxic gas in the liquid tank using air supplied from the second air intake part. And a second air flow generating means for generating a substantially horizontal second air flow directed to the side, when the processing operation such as a cleaning operation is sequentially performed on an object to be processed such as a silicon wafer, It is possible to more effectively suppress discharge of harmful gas generated above the liquid tank to the outside of the draft chamber or to the clean room.

  Further, when the draft chamber according to the present invention includes the first return pipe that connects the exhaust portion of the gas-liquid contact device and the first intake portion, the processing air discharged from the gas-liquid contact device is directly used as the first. Since air can be supplied to the air flow generating means, air can be circulated in the draft chamber. This eliminates the need to supply new air from outside the draft chamber.

  Further, when the draft chamber according to the present invention includes the second return pipe that connects the exhaust portion of the gas-liquid contact device and the second intake portion, the processing air discharged from the gas-liquid contact device is left as it is. Since air can be supplied to the air flow generating means, air can be circulated in the draft chamber. This eliminates the need to supply new air from outside the draft chamber.

  Further, in the draft chamber according to the present invention, when the exhaust portion and the first intake portion of the gas-liquid contact device communicate with the clean room, the process air discharged from the gas-liquid contact device is exhausted to the clean room as it is, and Since clean air can be supplied from the clean room to the first air flow generating means, air can be circulated and used in the clean room. For this reason, it is not necessary to introduce new air into the clean room from the outside of the clean room, and electric power for cleanly processing the air becomes unnecessary.

  Further, in the draft chamber according to the present invention, when the second intake portion communicates with the clean room, the processing air discharged from the gas-liquid contact device is discharged to the clean room as it is, and the clean air is discharged from the clean room to the second air. Since it can supply to a flow generation means, air can be circulated and used in a clean room. For this reason, it is not necessary to introduce new air into the clean room from the outside of the clean room, and electric power for cleanly processing the air becomes unnecessary.

  Further, the gas-liquid contact device of the draft chamber according to the present invention includes a water storage tank for storing the discharged water of the gas-liquid contact device, a circulation pipe for connecting the water storage tank and the water supply means, and a middle of the circulation pipe. When provided with a circulation pump that supplies water from the water storage tank to the water supply means, water can be circulated and used in the gas-liquid contact device, and the processing cost of air purification can be reduced. it can.

  The draft chamber according to the present invention is a rinsing tank in which at least one of the liquid tanks uses pure water or ultrapure water, and when a drain pipe from the rinsing tank is led to the water storage tank, The discharged water can be reused for air purification in the gas-liquid contact device, and the processing cost of air purification can be reduced.

  Since the cleaning device according to the present invention includes the draft chamber and the gas-liquid contact device, it is possible to remove harmful gas generated during chemical solution processing without exhausting it outside the draft chamber or the clean room. The removed clean air can be reused.

  In addition, when a slanted honeycomb is used as a gas-liquid contact device, the removal efficiency of harmful gas is higher than that of a conventionally used water shower, so a cleaning device that removes harmful gas in the air with a small removal device and a small amount of removed water It can be removed without discharging outside or clean room. In addition, since the slanted honeycomb has a thin wall thickness, air pressure loss is reduced, which is advantageous in terms of running cost.

  In addition, since the cleaning apparatus according to the present invention does not discharge harmful gas as described above, the space-saving property of the apparatus can be improved by installing the draft chamber main body and the gas-liquid contact apparatus in the clean room.

  In addition, the cleaning device according to the present invention includes a first air intake unit, and first air flow generating means for generating a first air flow from the upper side to the lower side in the processing chamber using air supplied from the first air intake unit. , The discharge of harmful gas inside the processing chamber to the outside of the draft chamber or to the clean room can be more effectively suppressed.

  When the cleaning device according to the present invention includes the first return pipe that connects the exhaust portion of the gas-liquid contact device and the first intake portion, the processing air discharged from the gas-liquid contact device is directly used as the first. Since air can be supplied to the air flow generating means, air can be circulated in the draft chamber. This eliminates the need to supply new air from outside the draft chamber.

  Further, in the cleaning device according to the present invention, when the exhaust part and the first intake part of the gas-liquid contact device communicate with the clean room, the process air discharged from the gas-liquid contact device is exhausted to the clean room as it is, and Since clean air can be supplied from the clean room to the first air flow generating means, air can be circulated and used in the clean room. For this reason, it is not necessary to introduce new air into the clean room from the outside of the clean room, and electric power for cleanly processing the air becomes unnecessary.

  In addition, the gas-liquid contact device of the cleaning device according to the present invention includes a water storage tank for storing the discharged water of the gas-liquid contact device, a circulation pipe connecting the water storage tank and the water supply means, and in the middle of the circulation pipe. When provided with a circulation pump that supplies water from the water storage tank to the water supply means, water can be circulated and used in the gas-liquid contact device, and the processing cost of air purification can be reduced. it can.

(First embodiment)
A first embodiment 1a of the draft chamber according to the present invention will be described with reference to FIGS. FIG. 1 is a front view of the first embodiment 1a. 2 is a sectional view taken along line AA in FIG. 1, FIG. 3 is a sectional view taken along line BB in FIG. 1, and FIG. 4 is a sectional view taken along line CC in FIGS. FIG. 5 is a diagram including a cross-sectional view taken along line DD of FIGS. 1 and 2 and a schematic diagram of other portions.

  The draft chamber 1a includes a draft chamber body 2 and a gas-liquid contact device 91, and is installed in a clean room. A first intake portion 4 for taking clean air into the draft chamber main body 2 from the outside of the draft chamber main body 2 is provided on the ceiling portion in the draft chamber main body 2. In the ceiling portion, clean air taken from the first air intake portion 4 is used to generate a first air flow (hereinafter also referred to as “down flow”) from the upper side to the lower side in the processing chamber 3. A first intake fan 50 and a second intake fan 60 are provided as one air flow generating means 6.

  As shown in FIG. 5, the first air supply fan 50 introduces clean air discharged from the gas-liquid contact device 91 through the first air intake portion 4 including the prefilter 52, and the ceiling duct 54 and the HEPA filter A down flow directed downward from the ceiling (upper) is sent via 56. Further, as shown in FIG. 4, the second intake fan 60 introduces clean air exhausted from the gas-liquid contact device 91 through the first intake section 4 having the pre-filter 62, and the ceiling duct 64 and the HEPA filter. The down flow is sent out through the control unit 66.

  In the draft chamber 1a, the downflow generated in the processing chamber 3 is sent from the duct 64 and the HEPA filter 66 on the near side with respect to the front surface of the draft chamber main body 2, and the back flow with respect to the front surface of the draft chamber main body 2. There are two types, one that is sent from the side duct 54 and the HEPA filter 56, and thus a two-layer flow downflow is formed. What is necessary is just to determine suitably the flow velocity and flow volume of each layer in the downflow of a two-layer flow.

  For example, when the flow rate of the down flow blown out from the HEPA filter 56 is normally 0.1 to 0.5 m / s, preferably 0.2 to 0.3 m / s, the air flow of seal air described later is not disturbed. Can do. Further, when the flow rate of the downflow blown out of the HEPA filter 66 is set to 0.5 m / s at the maximum and slightly faster than the downflow on the back side, harmful gas is introduced into the clean room from the carrier operation windows 14 and 16 described later. Can be prevented from being discharged. In the present invention, the harmful gas is not particularly limited as long as it is a water-soluble gas. Examples of such harmful gases include ammonia, HF, sulfuric acid, hydrochloric acid, nitric acid, acetic acid, hydrogen peroxide solution, isopropyl alcohol, and the like.

In the processing chamber 3 of the draft chamber main body 2, _four tanks of an NH ₄ OH + H ₂ O ₂ chemical liquid tank 20, a rinse tank 22, an HF chemical liquid tank 24, and a rinse tank 26 are sequentially arranged as liquid tanks. Among these, the chemical liquid tank 20 is provided with a heater 34, the chemical liquid tanks 20 and 24 are supplied with chemical liquid from a chemical liquid supply device, and the rinse tanks 22 and 26 are supplied with ultrapure water. Also, as shown in FIGS. 4 and 5, the waste liquid in each liquid tank is drained from the bottom of the liquid tank via an automatic drain valve 32.

In 1st Embodiment 1a, it can be used for the chemical cleaning process or etching process of a silicon wafer by setting it as such a tank structure. That is, the silicon wafer carrier 160 is first immersed in the NH ₄ OH + H ₂ O ₂ chemical bath 20 to perform chemical cleaning treatment of the silicon wafer on the carrier 160, and then immersed in the rinse bath 22 to clean the chemical solution. Furthermore, it can be immersed in the HF chemical bath 24 for cleaning, and finally immersed in the rinse bath 26 to clean the chemical. Note that the chemical cleaning process or the etching process includes a total of three modes: only the chemical cleaning process, only the etching process, and both the chemical cleaning process and the etching process.

  Further, in the work chamber 3, a carrier transfer device 30 is provided for transferring the wafer carrier 160 from the carrier supply unit 27 to the wafer take-out unit 28 via each liquid tank. As shown in FIG. 4, the carrier transfer device 30 is configured to be movable in the vertical direction so that the wafer carrier 160 is immersed in each liquid bath. Further, carrier operation windows 14 and 16 are provided on the front surface of the draft chamber body 2 so that the wafer carrier 160 can be easily taken in and out. In the first embodiment 1a, by providing the carrier transfer device 30 as described above, the chemical cleaning process or the etching process of the silicon wafer can be easily performed.

  At the bottom of the draft chamber main body 2, a second intake portion 5 for taking clean air into the draft chamber main body 2 from the outside of the draft chamber main body 2 is provided. The bottom of the draft chamber body 2 uses clean air taken from the second intake section 5 and is substantially horizontal from the front side to the back side of the front side of the draft chamber body 2 above the chemical tanks 20 and 24. A seal air fan 40 is provided as second air flow generation means for generating a second air flow (hereinafter also referred to as “seal air”).

  As shown in FIGS. 3 and 4, the seal air fan 40 sucks clean air that has passed through the gas-liquid contact device 91 and is taken in via the HEPA filter 44 in the second intake section 5, and is located above the chemical tanks 20 and 24. The seal air is sent out from the blowout ports 48 and 48 through the ducts 46 and 48 respectively provided correspondingly. Each of these air outlets 48 includes an upper air outlet 48A and a lower air outlet 48B, so that two-layered seal air can be sent out. For example, the flow rate of the seal air sent from the lower side blowing port 48B is set to about 0.2 m / s, and the flow rate of the seal air sent from the upper side blowing port 48A is made higher than this. Accordingly, it is possible to reduce the evaporation amount of the chemical liquid, to prevent the collision turbulent flow of the airflow to the piping, and to eliminate the risk of mist scattering.

As shown in FIG. 4 and FIG. 5, there are _four tanks of NH ₄ OH + H ₂ O ₂ chemical solution tank 20, rinse tank 22, HF chemical solution tank 24, and rinse tank 26 at the back side in the processing chamber 3 of the draft chamber body 2. Exhaust ducts 72 and 74 are provided on the back side above the upper side, and a duct 78 communicating with the duct 74 is further provided on the near side above the rinse tanks 22 and 26. Further, as shown in FIG. 1 and FIG. 4, an intake port 76 </ _b > A is further provided at a position on the back side above the NH ₄ OH + H ₂ O ₂ chemical solution tank 20 and the HF chemical solution tank 24 and substantially opposed to the outlets 48 </ _b > A and 48 </ _b > B. Ducts 76, 76 having 76A are provided.

  These ducts 72, 74, 76, and 78 are sequentially joined and finally communicated with the exhaust part 8 of the draft chamber body 2, whereby all the exhaust in the processing chamber 3 is gas-liquid contact device 91. To be supplied. Note that dampers 72A, 74A, and 78A are provided at the air inlets of the ducts 72, 74, and 78, respectively, so that the downflow and the seal air flow rate can be adjusted to arbitrary amounts, respectively. A fluorescent lamp 92 is provided in the processing chamber 3, and a control unit 90 and a solution filter 94 are provided outside the processing chamber 3 of the draft chamber body 2.

  As shown in FIGS. 2 to 4, an exhaust pipe 81 is connected to each exhaust section 8 of the draft chamber body 2. The exhaust pipe 81 is integrated into an intake pipe 82 and connected to the gas-liquid contact device 91. The gas-liquid contact device 91 includes a skewed honeycomb 111, a water supply unit 21 that supplies water to the skewed honeycomb 111, and a water discharge unit 15 that discharges water discharged from the skewed honeycomb 111 to the outside of the gas-liquid contact device 91. Consists of.

  The skew honeycomb 111 will be described with reference to FIG. The skewed honeycomb 111 has a honeycomb shape formed by laminating a plurality of corrugated sheets 112 and 113 (hereinafter also referred to as corrugated sheets) having a corrugated shape propagating in one direction. The sheet-like sheets 112 and 113 are laminated so that the wave propagation directions are obliquely intersected with each other, and the honeycomb sheets are arranged so that the wave propagation directions of every other layer are substantially the same direction. Is the body.

  The skewed honeycomb 111 is cut by four planes 101 to 104 perpendicular to the plane parallel to the corrugated sheets 112 and 113 to form a rectangular parallelepiped, and the cut plane is a wave propagation direction of the corrugated sheet. When the rectangular parallelepiped is arranged so that one of the cut surfaces 104 is a lower surface and the outermost layers 105 and 106 of the corrugated sheet are respectively left and right surfaces, The four sides of the front and rear surfaces 102 and 103 and the upper and lower surfaces 101 and 104 have a structure in which a honeycomb cell is opened, and the left and right surfaces 105 and 106 are closed by corrugated sheets. That is, the oblique honeycomb 111 has a structure in which the front and rear surfaces 102 and 103 and the upper and lower surfaces 101 and 104 are opened.

  Further, for example, the front and rear surfaces 102 and 103 of the cut surface are formed with cells extending obliquely upward and cells extending obliquely downward. The oblique angle (symbol X in the figure) with respect to the inflow and outflow direction (horizontal direction) of air when viewed from both front and rear surfaces of the cell extending obliquely upward is usually 15 to 45 degrees, preferably 25 to 35 degrees. Within range. It is preferable that the oblique angle is within this range because the flow velocity is in an appropriate range and the contact efficiency is improved.

  In the skewed honeycomb 111, the angle (in the figure, symbol Y) at which the wave propagation directions of the laminated corrugated sheets cross each other is usually 30 to 90 degrees, preferably 50 to 70 degrees. When the corrugated sheets are laminated so as to intersect within the above angle range, when the oblique angle (X) is set to 15 to 45 degrees as described above, the air and water to be treated are substantially separated from the honeycomb cells. This is preferable because the contact efficiency between the air to be treated and water is increased.

  That is, as will be described later, in the present invention, the air to be treated is introduced from the front opening 103 of the skewed honeycomb 111, and the water is supplied from the upper surface opening 101 by the water supply duct 114 which is the water supply means 21. Since it penetrates into the corrugated sheet and slowly flows down the corrugated sheet's pole surface, the air flow direction of the treated air and the water flow direction of the infiltrated wall keep an appropriate angle, and the contact efficiency is high. Because it becomes.

  The height of the cells of the slanted honeycomb used in the present invention, that is, the height of the cell showing the dimension between the top and the valley of the corrugated peak is usually 2 to 8 mm, preferably 3 to 5 mm. If the height of the cell is less than 2 mm, the production is difficult and the pressure loss increases, which is not preferable. Moreover, since the gas-liquid contact efficiency will fall when the peak height of a cell exceeds 8 mm, it is unpreferable.

  The cell width in the state of the corrugated sheet of the skewed honeycomb, that is, the cell pitch is usually 2.5 to 12.0 mm, preferably 5.0 to 10.0 mm.

The dimension between the front opening and the rear opening of the skewed honeycomb, that is, the thickness (t) of the skewed honeycomb is usually 100 to 1000 mm, preferably 200 to 800 mm. If the thickness is less than 100 mm, the removal efficiency of NH ₃ or the like is lowered, which is not preferable. If the thickness exceeds 100 mm, the removal efficiency of chemical contaminants is not further improved, and the pressure loss increases. It is not preferable. When chemical contaminants are removed and dehumidified with a single honeycomb during periods of high humidity such as during the rainy season, it is better to use a thick one with a thickness of about 800 mm in order to perform sufficient dehumidification.

  In the present invention, the thickness of the skew honeycomb may be such that the total thickness is within the above range when a plurality of skew honeycombs are used. For example, when a skewed honeycomb having a thickness of 300 mm is used, three skewed honeycombs having a thickness of 100 mm may be stacked in the thickness direction so that the total thickness is 300 mm. When the skew honeycomb is used, the thickness of the skew honeycomb itself is about 400 mm at most, so that the installation space of the apparatus can be greatly reduced. Such a large space saving satisfies the demand for rationalization of semiconductor manufacturing factories and the like. Furthermore, the capacity of the pump that circulates water is much smaller than that of the conventional water shower, and a significant energy saving can be achieved.

  The corrugated sheets 112 and 113 constituting the slanted honeycomb are made of the same material as this and are formed by forming a flat sheet-like member into a corrugated shape. As the sheet-like member used in the present invention, if the surface has irregularities and the inside is porous, the surface of the element can be greatly searched, and the contact area between water and air that permeates and flows down the element increases. Therefore, it is preferable. Such a sheet-like member comprises, for example, one or more fillers or binders selected from the group consisting of alumina, silica, and tania, and a fiber base material such as glass fiber, ceramic fiber, or alumina fiber. And glass fiber, ceramic fiber or alumina fiber substrate containing the filler or binder. Of these, those containing titania are preferred because the removal efficiency of acidic chemical contaminants is improved. Further, the sheet-like member usually contains 60 to 93% by weight of filler or binder and 7 to 40% by weight of fiber base material, preferably 70 to 88% by weight of filler or binder and 12% of fiber base material. Contains ~ 30% by weight. It is preferable that the blending ratio of the sheet-shaped member is within the above range because the water permeability and strength of the sheet-shaped member are high.

  The sheet-like member can be prepared by a known method. For example, a paper made of glass fiber, ceramic fiber or alumina fiber is dipped in a slurry in which a binder such as alumina sol and alumina hydrate are mixed, and then dried. And corrugating, followed by drying and heat treatment to remove moisture and organic matter.

  When silica or titania is contained in addition to alumina, for example, the blending amount of silica and titania is usually 5 to 40 parts by weight with respect to 100 parts by weight of alumina.

In the skew honeycomb, the thickness of the sheet-like member is usually 200 to 1000 μm, preferably 300 to 800 μm. The porosity of the sheet-like member forming the skewed honeycomb is usually 50 to 80%, preferably 60 to 75%. Here, the porosity (%) is represented by the following formula (1), where d ₁ is the true density of the material and d ₂ is the apparent density of the material.

{1- (d ₂ / d ₁ )} × 100 (1)
By setting the porosity within the above range, it is possible to achieve moderate permeability and increase the contact efficiency between air and water. Further, when the sheet-like member has the above thickness and void ratio, the liquid gas ratio and the water permeation rate are in an appropriate range, and the contact efficiency between water and air is enhanced and the strength is sufficient.

  Examples of a method for forming the sheet-like member into a corrugated sheet include a method using a known corrugator in which a parallel sheet is passed between a plurality of gears having corrugated irregularities that are oscillated in the radial direction. . As a method of forming the above skew honeycomb from the obtained corrugated sheet, first, for example, the corrugated sheet is propagated with respect to a rectangular cutting die having a length of about 100 mm (thickness dimension after forming) × width of about 3000 mm. A rectangular corrugated sheet is produced by arranging and cutting so that the direction is 15 to 45 degrees with respect to one side of the rectangular shape, and then the propagation direction of the waves every other rectangular corrugated sheet obtained. Can be arranged so as to be skewed and bonded and laminated. When manufactured in this way, the vertical length of the cutting mold is the thickness of one skewed honeycomb. For this reason, for example, when the thickness of the skewed honeycomb necessary for the humidifying means and the condensing means, that is, when the dimension between the front opening and the rear opening of the skewed honeycomb is 300 mm, the cutting mold has a length of 100 mm. Three skewed honeycombs having a thickness of 100 mm produced in the above may be used in the thickness direction. In addition, when a plurality of sheets are used in such a manner, the skewed honeycombs may be bonded or not bonded. When not bonding, it is only necessary to stack a plurality of skew honeycombs.

  In the present invention, the skewed honeycomb is arranged such that the front and rear surfaces 103 and 102 and the upper and lower surfaces 101 and 104 are opened. By arranging the skewed honeycomb in this way, it becomes possible to introduce the air to be treated from the front opening 103 of the skewed honeycomb and to supply water from the top opening 101, and to treat the air to be treated and the water. The contact is performed such that the direction of air to be treated and the direction of water flow are orthogonal. As described above, by using the skewed honeycomb as the gas-liquid contact means, it is possible to obtain clean treated air from which chemical contaminants contained in the air to be treated are removed to the extent that it does not cause a problem in the clean room. The air to be treated passes through the skewed honeycomb 111 to become clean treated air, and is then discharged out of the gas-liquid contact device 91 through the exhaust pipe 83.

  The water supply means 21 is means for supplying water from the upper surface to the upper surface opening 101 of the skewed honeycomb 111. An example of the water supply means 21 is a water supply duct 114 shown in FIG. The water discharge means 15 is means for receiving water discharged from the lower surface opening 104 of the skewed honeycomb 111 and discharging this water out of the gas-liquid contact device 91 system. An example of the water discharging means 15 is a water receiving pan 115 shown in FIG. A drain port connected to the drain pipe 15b is provided on the bottom surface of the water receiving pan 15, and the drainage can be discharged out of the gas-liquid contact device 91 system.

  The drain pipe 15 b is connected to the water storage tank 25. The water storage tank 25 is provided with a water supply pipe 23 through which pure water can be injected from the outside, and a drain pipe 100 for discharging the stored pure water to the outside is provided at the bottom of the water storage tank 25. Therefore, the water in the water storage tank 25 can maintain an appropriate water quality and amount. A circulation pipe 17 and a circulation pump 18 are provided between the bottom of the water storage tank 25 and the water discharge means 15. Water in the water storage tank 25 is supplied to the water supply means 21, and the gas-liquid contact device 91. Water can be circulated and used inside.

  The type of water used in the gas-liquid contact device 91 is not particularly limited as long as it can collect and remove harmful gas components, but pure water or the like is usually used. The pure water may be reused as long as harmful gas components can be collected and removed. For example, in the first embodiment 1a, when the drain pipe 15c and the drain pipe 15b from the rinse tank 26 are connected so that the pure water used in the rinse tank 26 can be guided to the water storage tank 25, the rinse tank Waste water having a purity of substantially pure water can be reused by the gas-liquid contact device 91.

  Between the exhaust part 9 of the gas-liquid contact device 91 and the first intake part 4 of the draft chamber body 2, a first return pipe 84 is provided to connect them. In the first embodiment 1a, the first intake section 4 is provided as an air intake port for each of the first intake fan 50 and the second intake fan 60. For this reason, the first return pipe 84 connected to the exhaust section 9 via the exhaust pipe 83 branches into the first return pipe 86 and the first return pipe 88 on the way, and the first return pipe 86 is the first intake fan. The first return pipe 88 is connected to the prefilter 52 provided in the first intake section 4 on the second intake fan 60 side, and the prefilter 52 provided in the first intake section 4 on the 50 side. It has become. Thus, in the first embodiment 1a, the processing air cleaned by the gas-liquid contact device 91 is reused as clean air introduced into the draft chamber body 2.

  In addition, a second return pipe 85 that connects the exhaust unit 9 and the second intake unit 5 of the gas-liquid contact device 91 is provided via the HEPA filter 42. Thus, in the first embodiment 1a, the processing air cleaned by the gas-liquid contact device 91 is reused as clean air introduced into the seal air fan 40.

  The operation of the first embodiment 1a will be described. The harmful gas generated from the chemical tanks 20 and 24 is sealed by the substantially horizontal seal air from the blowout ports 48A and 48B toward the intake port 76A of the guide duct 76, and hardly flows out above the seal air. Even when harmful gas flows out of the seal, the exhaust gas is discharged from the exhaust ducts 72 and 74 by the two-layer downflow sent from the HEPA filters 56 and 66, so that the diffusion of the harmful gas in the processing chamber 3 is performed. Is prevented. Further, air containing harmful gas or the like discharged from the exhaust section 8 of the draft chamber body 2 through the exhaust ducts 72 and 74 and the guide duct 76 is cleaned by the gas-liquid contact device 91 and is supplied to the first return pipe 84. Is returned to the first intake section 4 via the second return pipe 85 and returned to the second intake section 5 via the second return pipe 85, so that no toxic gas is substantially discharged out of the draft chamber 1 a.

  The cleaning of the air to be processed in the gas-liquid contact device 91 will be described in more detail. Supply water 116 is supplied from the water supply duct 114 to the upper surface opening 101 of the skewed honeycomb 111 by the gas-liquid contact device 91 including the skewed honeycomb 111 arranged in the predetermined direction, the water supply means 21 and the water discharge means 15. Then, it flows down through the oblique honeycomb 111 and is discharged from the lower surface opening 104 to the water discharge means 15 as discharged water 117, and further discharged from the gas-liquid contact device 91 system by the water discharge means 15.

  The discharged water 117 discharged from the gas-liquid contact device 91 system by the water discharging means 15 is stored in the water storage tank 25 through the drain pipe 15b. Then, the water is circulated to the water supply means 21 by the circulation pipe 17 connecting the water storage tank 25 and the water discharge means 15 and the circulation pump 18 provided in the middle of the circulation pipe 17, and again into the skewed honeycomb 111 of the gas-liquid contact device 91. Supplied.

In the first embodiment 1a, the downflow of the front and rear two layers is generated by the separate intake fan first supply fan 50 and second intake fan 60, respectively, but is not limited to this. For example, an air flow generated from one intake fan may be branched so as to have a required air volume (wind speed) to generate a two-layer downflow. Further, in the case of an apparatus that fully automates the conveyance of the carrier 160 and the like, it is not necessary to open the front operation door, so the downflow may be made into one layer by integrating the airflow from the ceiling. In this case, it can be set as the structure which uses one each for a ventilation fan and a HEPA filter. In the first embodiment 1a, the second air flow generating means is provided to prevent leakage of harmful gas, but processing operations such as carrier transport and cleaning operations are completely performed. When it is not necessary to open the front operation window as in the case of an automated device, the second air flow generation means may not be provided.
(Second Embodiment)
Next, a second embodiment 1b of the draft chamber according to the present invention will be described with reference to FIG. FIG. 6 is a diagram including a cross-sectional view taken along a portion similar to the embodiment 1a of FIG. 4 and a schematic view of other portions in the second embodiment 1b.

  The difference between the second embodiment 1b and the first embodiment 1a is that the first return pipe 86 and the second return pipe 85 are provided in the first embodiment 1a. These are not provided in the second embodiment 1b, and the exhaust part 9, the first intake part 4, and the second intake part 5 of the gas-liquid contact device 91 are configured to communicate with the clean room, respectively. It is in. Since other parts are the same as those in the first embodiment 1a, the same members are denoted by the same reference numerals and description thereof is omitted.

  In the second embodiment 1b, the first intake section 4 communicates with the clean room via the pre-filter 62 and the pre-filter 52 (not shown), and the intake fan second intake fan 60 enters the draft chamber body 2 from the clean room. And it has the structure which takes in clean air via the 1st air supply fan 50 which is not shown in figure. The second intake section 5 communicates with the clean room via the HEPA filter 42 and has a structure for taking clean air from the clean room into the draft chamber body 2. Further, the exhaust unit 9 of the gas-liquid contact device 91 communicates with the clean room via a HEPA filter (not shown) so that clean air processed by the gas-liquid contact device 91 is discharged into the clean room. The HEPA filter (not shown) is not essential for the present invention, and clean air may be discharged directly into the clean room without using a filter.

The action of the second embodiment 1b is that the air purified by the gas-liquid contact device 91 is returned to the first intake section 4 via the first return pipe 84 in the first embodiment 1a. In contrast to the return to the second intake section 5 through the second return pipe 85, in the second embodiment 1b, the air is discharged to the clean room through a HEPA filter (not shown), and the second intake section 4 also has the second intake. Except that it is not returned to the intake section 5, it is the same as the first embodiment 1a. Note that when the clean air cleaned by the gas-liquid contact device 91 is discharged into the clean room, the humidity of the clean air and the humidity in the clean room are usually different. It is preferable to discharge.
(Third embodiment)
Next, a third embodiment 1c using the draft chamber according to the present invention as a cleaning device will be described with reference to FIG. FIG. 8 is a schematic view of a third embodiment 1c which is a single wafer cleaning apparatus. In the cleaning apparatus 1 c, the draft chamber main body 151 includes a processing chamber 3 and an intake fan 161 provided outside the processing chamber 3, and the exhaust unit 8 provided below and to the side of the turntable 155 in the processing chamber 3. Is connected to a gas-liquid contact device 91 similar to that of the first embodiment 1a. A first return pipe 84 is connected to the exhaust part 9 of the gas-liquid contact device 91 and is connected to the intake fan 161 via the first intake part 4. The gas-liquid contact device 91 is provided with a water storage tank 25, a circulation pipe 17 and a circulation pump 18 similar to those in the first embodiment 1a so that water can be reused in the gas-liquid contact device 91. It has become.

  In the processing chamber 3, there is provided a turntable 155 that is attached to the upper end portion of a rotating shaft 154 driven by a motor 153 and that can rotate while holding the workpiece 152 placed thereon under reduced pressure suction. It has been. Further, above the turntable 155, a nozzle 156 capable of spraying a chemical solution or the like on a workpiece 152 such as a silicon wafer placed on the turntable 155 is provided. A discharge port 163 for discharging a chemical solution or the like out of the processing chamber 3 is provided at the bottom. A drain pipe from the discharge port 163 communicates with the chemical tank 157 so that the collected chemical can be stored in the chemical tank 157. A discharge port is provided at the bottom of the chemical tank 157, and a drain pipe from the discharge port is connected to the nozzle 156 via a circulation pump 158 and a circulation filter 159.

  The operation of the third embodiment 1c will be described. First, with the turntable 155 and the workpiece 152 such as a silicon wafer rotated, the chemical solution is sprayed from the nozzle 156 onto the workpiece 152 to clean the workpiece 152. The chemical liquid blown off by the rotation is collected in the chemical liquid tank 157 from the discharge port 163 at the bottom of the processing chamber 3. This chemical solution is sent to the nozzle 156 by the circulation pump 158 and the circulation filter 159 and reused as the chemical solution.

  On the other hand, in the processing chamber 3, the clean air supplied from above by the intake fan 161 is discharged from the exhaust port 8 provided below, so that a downflow is formed, and the chemical liquid scattered in the processing chamber 3 is formed. The mist is prevented from being discharged from a carrier operation window (not shown). The air discharged from the exhaust port 8 is sent to the gas-liquid contact device 91, washed with clean pure water supplied from the water supply means 21, converted into clean air, and discharged from the gas-liquid contact device 91. The air is sent from the return pipe 84 to the intake fan 161 via the first intake section 4 and reused. Further, in the gas-liquid contact device 91, water is reused as in the first embodiment 1a.

  The draft chamber and the cleaning apparatus according to the present invention can be used, for example, in a draft chamber and a cleaning apparatus used for chemical cleaning and etching of a silicon wafer or the like using a chemical solution in a semiconductor manufacturing process.

  Examples are shown below, but the present invention is not construed as being limited thereto.

The draft chamber 1a was operated under the following conditions in a clean room, and the ammonia concentration in the exhaust air from the draft chamber 1a was measured.
(Setting conditions for skew honeycomb)
The skew honeycomb used for the gas-liquid contact device of the draft chamber 1a was produced as follows. First, a slurry containing an alumina sol as a binder and an alumina hydrate as a filler is prepared, and the slurry is supported on glass paper and corrugated to give a corrugated sheet having a peak height of 4.8 mm and a pitch of 10 mm. Got. The corrugated sheet had a thickness of 500 μm, a porosity of 65%, and was composed of 80% by weight of alumina and 20% by weight of E glass fiber.

  Next, the corrugated sheets were laminated one by one so that the angle at which every other wave propagation direction intersects each other (reference numeral Y in FIG. 7) was 60 °, and then heat treated at 500 ° C. An oblique honeycomb having an outer shape of a width of 400 mm × height of 400 mm and an outer shape of approximately 200 mm in depth was obtained. This skew honeycomb was prepared so that the wave extending direction of the corrugated sheet was substantially vertical, and the front and back and upper and lower surfaces had opening surfaces, and ventilation was possible in these directions. On the other hand, the corrugated sheet obstructs ventilation in the directions of the two left and right surfaces so that the ventilation cannot be performed substantially.

This skewed honeycomb was housed in a case having front and rear opening surfaces of width 400 mm × height 400 mm and depth 200 mm so that the angle X in FIG. Three skew honeycombs housed in this case were arranged in the depth direction so that the total depth (length in the ventilation direction) of the skew honeycomb portions in the gas-liquid contact device was 600 mm.
(Draft chamber body chemical treatment conditions)
The chemical tank 20 was filled with buffered hydrofluoric acid mixed at a concentration of ₄ wt% HF and 20 wt% NH ₄ F. The HF chemical tank 24 was filled with 0.5% by weight of HF. Further, pure water was supplied to the rinsing tank 22 and the rinsing tank 26.

The first intake fan 50 and the second intake fan 60 are operated, and the seal air fan 40 is further operated to supply clean air from the outlets 48A and 48B at a supply air volume of 20 m ³ / min. The air flow (seal air) which discharged | emitted and flows substantially parallel along the chemical | medical solution tank 20 surface above the chemical | medical solution tank 20 was formed.

Next, when the temperature of the buffered hydrofluoric acid in the chemical solution tank 20 was adjusted to 25 ° C., ammonia was generated from the chemical solution tank 20. At this time, the ammonia concentration in the exhaust in the exhaust part 8 of the draft chamber body 2 (inlet part of the gas-liquid contact device 91) was 100 μg / m ³ . Further, the ammonia concentration in the exhaust gas at the exhaust part 9 of the gas-liquid contact device 91 (the outlet part of the gas-liquid contact device 91) was 0.8 μg / m ³ . The latter ammonia concentration is a concentration that does not interfere with semiconductor manufacturing even if the exhausted air is returned to the draft chamber and recirculated.

FIG. 1 is a front view of the first embodiment 1a. 2 is a cross-sectional view taken along line AA in FIG. 3 is a cross-sectional view taken along line BB in FIG. FIG. 4 is a diagram including a cross-sectional view taken along the line CC of FIGS. 1 and 2 and schematic diagrams of other portions. FIG. 5 is a view including a cross-sectional view taken along the line DD in FIGS. 1 and 2 and schematic diagrams of other portions. FIG. 6 is a diagram including a cross-sectional view taken along a portion similar to the embodiment 1a of FIG. 4 and a schematic view of other portions in the second embodiment 1b. FIG. 7 is a diagram illustrating a skewed honeycomb. FIG. 8 is a schematic diagram of the third embodiment 1c.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a, 1b Draft chamber 1c Cleaning apparatus 2, 151 Draft chamber main body 3 Processing chamber 4 1st air intake part 5 2nd air intake part 6 1st airflow generation means 7 2nd airflow generation means 8 Exhaust part of draft chamber main body 9 Exhaust part of gas-liquid contact device 14, 16 Carrier operation window 15 Water discharge means 15b, 15c, 100 Drain pipe 17 Circulation pipe 18 Circulation pump 21 Water supply means 20, 24 Chemical solution tank,
22, 26 Rinse tank 23 Water supply pipe 25 Water storage tank 30 Carrier transfer device 40 Seal air fan 42 HEPA filter 50 First intake fan 52, 62 Pre-filter 60 Second intake fan 81, 83 Exhaust pipe 84, 86, 88 First return Piping 85 Second return piping 91 Gas-liquid contact device 111 Skewed honeycomb 114 Water supply duct 115 Water receiving pan 116 Supply water 117 Discharged water 152 Silicon wafer (object to be processed)
154 Rotating shaft 155 Turntable 156 Nozzle 157 Chemical solution tank 158 Circulation pump 159 Circulation filter 160 Wafer carrier 163 Discharge port

Claims (17)

  A draft chamber comprising: a draft chamber main body; and a gas-liquid contact device that is connected to an exhaust portion of the draft chamber main body and purifies exhaust from the exhaust portion.   The draft chamber according to claim 1, wherein the gas-liquid contact device uses a skewed honeycomb.   The draft chamber according to claim 1 or 2, wherein the draft chamber body and the gas-liquid contact device are installed in a clean room.   The draft chamber body includes a first air intake unit and first air flow generating means for generating a first air flow from the upper side to the lower side in the processing chamber using air supplied from the first air intake unit. The draft chamber according to any one of claims 1 to 3.   The draft chamber main body includes a liquid tank in the processing chamber, and from the front side of the front side of the draft chamber main body above the liquid tank using a second air intake unit and air supplied from the second air intake unit. 5. The draft chamber according to claim 4, further comprising second air flow generating means for generating a substantially horizontal second air flow toward the rear side.   The draft chamber main body includes a plurality of liquid tanks in the processing chamber, and a second air intake unit and air supplied from the second air intake unit are used to form the draft chamber main body above at least one of the liquid tanks. 5. The draft chamber according to claim 4, further comprising second air flow generating means for generating a substantially horizontal second air flow from the front side toward the back side.   The draft chamber main body includes a plurality of liquid tanks in the processing chamber and a carrier transport device for sequentially immersing carriers in the plurality of liquid tanks, and further includes a carrier operation window on the front surface of the draft chamber main body. The front side of the front side of the draft chamber main body is directed from the front side to the back side above the liquid level of the chemical tank that generates at least a toxic gas in the liquid tank using the air supplied from the second air inlet part and the second air inlet part. 5. The draft chamber according to claim 4, further comprising second air flow generation means for generating a substantially horizontal second air flow.   The draft chamber according to any one of claims 4 to 7, further comprising a first return pipe connecting the exhaust part of the gas-liquid contact device and the first intake part.   The draft chamber according to any one of claims 5 to 8, further comprising a second return pipe connecting the exhaust part of the gas-liquid contact device and the second intake part.   The draft chamber according to any one of claims 4 to 7, wherein the exhaust part and the first intake part of the gas-liquid contact device communicate with a clean room, respectively.   The draft chamber according to any one of claims 5 to 8 and 10, wherein the second intake portion communicates with a clean room.   The skew honeycomb is formed of a glass fiber, a ceramic fiber, or an alumina fiber base material containing one or more fillers or binders selected from the group consisting of alumina, silica, and titania. The draft chamber according to any one of claims 1 to 11.   The gas-liquid contact device includes a water storage tank that stores the discharged water of the gas-liquid contact device, a circulation pipe that connects the water storage tank and the water supply means, and the water-liquid contact device provided in the middle of the circulation pipe from the water storage tank. The draft chamber according to any one of claims 1 to 12, further comprising a circulation pump for supplying water to the water supply means.   14. At least one of the liquid tanks is a rinse tank using pure water or ultrapure water, and a drain pipe from the rinse tank is led to the water storage tank. Draft chamber.   The draft chamber according to any one of claims 1 to 14, wherein the draft chamber is used for chemical cleaning treatment or etching treatment of a silicon wafer.   A turntable capable of placing and rotating an object to be processed in the processing chamber using the draft chamber according to any one of claims 1 to 4, 8, 10, 12, 13, and 15. A cleaning apparatus comprising: a nozzle capable of supplying a chemical solution onto the object to be processed.   The cleaning apparatus according to claim 16, wherein the object to be processed is a silicon wafer.

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