JP2006303116A - Cleaning equipment, cleaning method and semiconductor fabrication equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide cleaning equipment for reducing the cost of a cleaning liquid. <P>SOLUTION: The cleaning equipment comprises a cleaning tub 3 for cleaning a substrate, a tank 8 for supplying a cleaning liquid to the cleaning tub 3, a cleaning tub 4 for cleaning the substrate succeeding to the cleaning tub 3, a tank 9 for supplying the cleaning liquid to the cleaning tub 4, an ozone passing section 10 for regenerating the cleaning liquid by making ozone pass, a section 11 for regenerating the cleaning liquid by crystallization, and a pipe 32 for supplying the regenerated cleaning liquid to the tank 9. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cleaning apparatus, a cleaning method, and a semiconductor manufacturing apparatus for cleaning a glass substrate and a wafer to remove an organic film such as a resist in a manufacturing process of a liquid crystal panel, a PDP (plasma display panel) or a semiconductor.

  In general, a large amount of various cleaning liquids such as sulfuric acid and hydrogen peroxide are used in a cleaning process for removing or removing a resist in a process of manufacturing a liquid crystal panel or a semiconductor. Therefore, a large amount of waste liquid such as waste acid and waste alkali is generated, and the treatment of the waste liquid becomes a problem. As for the types of cleaning liquids that are used in large quantities, they have been collected and purified, and have been tried to be reused in manufacturing processes, etc., and various methods for regenerating cleaning liquids have been developed.

  In recent years, the size of the cleaning tank used has increased due to the increase in the size of the panel and the increase in the diameter of the wafer, and the capacity thereof has increased. Along with this, the amount of cleaning liquid used increases, which increases not only the cost of the cleaning liquid but also the processing cost and environmental burden of the cleaning liquid. For this reason, a new technique for reducing the amount of waste liquid as much as possible is required.

  For example, Patent Document 1 and Patent Document 2 are prior art documents of a cleaning apparatus having a cleaning liquid regeneration function.

  FIG. 8 is a diagram illustrating a configuration of the cleaning apparatus disclosed in Patent Document 1 and Patent Document 2. As illustrated in FIG. In the figure, the regenerator 533 regenerates by passing ozone through the used cleaning liquid in the first cleaning tank 519 out of two cleaning tanks. The regenerated cleaning liquid is supplied to the nozzle pipe 540 above the second cleaning tank 520 by the pump 535 and used as the cleaning liquid in the second cleaning tank 520. The used cleaning liquid in the second cleaning tank 520 is supplied from the recovery tank 522 to the nozzle pipe 529 by the pump 524 and used as the cleaning liquid in the first cleaning tank 519. This cleaning solution contains either ethylene carbonate or propylene carbonate, and has a characteristic that the resist stripping rate is extremely high as compared with the conventional cleaning solution. In addition, this cleaning solution has a high regeneration capability by ozone ventilation. That is, the reproducing apparatus 533 decomposes the organic substance (resist) peeled off from the substrate and dissolved in the cleaning liquid by causing ozone to flow through the cleaning liquid. Since the organic matter contains carbon and hydrogen, it is finally decomposed into carbon dioxide and water by ozone ventilation.

As described above, the above-described cleaning apparatus is suitable for miniaturization because it has high cleaning ability and high regeneration efficiency.
JP 2004-186208 A JP 2004-298552 A

  However, according to the conventional cleaning apparatus, although depending on the quantitative regeneration capability of the regenerator, impurities derived from the resist and acids generated in the decomposition process remain as impurities in the cleaning liquid after the regeneration. If it accumulates gradually, it will be necessary to replace | exchange cleaning liquid, and there exists a problem that the cost by replacement | exchange will be taken.

  The reason why the cleaning liquid needs to be periodically replaced is as follows. That is, when a substrate is unloaded from the cleaning tank to the next process, a thin cleaning solution remains on the substrate surface. If the remaining cleaning solution contains a large amount of impurities, the substrate surface is cleaned in the cleaning process with pure water in the next step. It may corrode circuit patterns (especially metals). This is because the impurities mentioned above are organic substances that are not completely decomposed in the process of decomposing the resist by ozone, and are acids (for example, formic acid, glyoxylic acid, maleic acid, phthalic acid, muconic acid, oxalic acid, mesoxalic acid). Etc., see FIG. 5A and FIG. 5B). The cleaning liquid that remains thinly on the substrate surface transported to the next process also contains such an acid. In this state, when the residual cleaning solution on the substrate is rinsed with pure water, the acid corrodes the wiring pattern. In order to avoid this, it is necessary to periodically replace the cleaning solution with a new cleaning solution so that the impurity concentration becomes a certain amount or less.

  Therefore, an object of the present invention is to provide a cleaning apparatus that reduces the cost of the cleaning liquid.

  In order to achieve the above object, the cleaning apparatus of the present invention includes a cleaning means for cleaning the substrate while circulating the cleaning liquid, a crystallization means for regenerating by crystallizing the cleaning liquid, and a cleaning means for cleaning the regenerated cleaning liquid. Supply means for supplying to the apparatus.

  According to this configuration, impurities dissolved in the cleaning liquid (impurities caused by the resist and acids generated in the decomposition process thereof) are separated by crystallization of the cleaning liquid, so that the cleaning liquid can be maintained at a high purity. The cleaning liquid can be used semipermanently, and there is an effect that the cleaning liquid replacement cost can be reduced.

  Furthermore, impurities that remain on the substrate surface and are taken to the next process can be reduced. Thereby, it is possible to prevent or reduce corrosion of the circuit pattern on the substrate surface in the cleaning process with pure water in the next step.

  Here, the cleaning liquid may contain either ethylene carbonate or propylene carbonate, and the crystallization means may crystallize a part of the cleaning liquid during the cleaning by the cleaning means.

  According to this configuration, since at least a part of the cleaning liquid is continuously obtained from the circulation path, crystallized, and returned to the circulation path, the cleaning liquid can be regenerated during operation without stopping the cleaning apparatus. In addition, since ethylene carbonate is solid at room temperature, crystallization can be facilitated.

  Here, the cleaning device further includes ozone aeration means for regenerating the cleaning liquid by aeration of ozone into the cleaning liquid after cleaning by the cleaning means, and refluxing the cleaning liquid after regeneration to the cleaning means, and the crystallization means A part of the cleaning liquid refluxed by the ozone ventilation means may be crystallized.

  According to this configuration, the impurities remaining without being decomposed by ozone ventilation are separated by crystallization and returned to the circulation path, so that the cleaning liquid can be regenerated during operation without stopping the cleaning device.

  Here, the cleaning means has at least two cleaning tanks for cleaning the substrate in stages, and the cleaning apparatus circulates the used cleaning liquid in the subsequent cleaning tank as the cleaning liquid in the previous cleaning tank. The ozone aeration means regenerates the used cleaning liquid in the first-stage cleaning tank by ozone ventilation and returns the regenerated cleaning liquid to the last-stage cleaning tank, and the supply means uses crystallization. You may make it supply the washing | cleaning liquid after reproduction | regeneration to the washing tank of the last stage.

  According to this structure, since it wash | cleans with a clean washing | cleaning liquid in the back | latter stage, it can wash | clean efficiently.

  Here, the cleaning means has at least two cleaning tanks for cleaning the substrate in stages, and the cleaning device circulates the used cleaning liquid in the final-stage cleaning tank to the final stage. A circulation means for circulating the used cleaning liquid in the cleaning tank other than the final stage to the cleaning tank other than the final stage, and the ozone ventilation means regenerates the cleaning liquid used in the cleaning tank other than the final stage by ozone ventilation and finally It may be refluxed to a cleaning tank other than the stage, and the supply means may supply the cleaning liquid after regeneration by crystallization to the final stage cleaning tank.

  According to this configuration, the cleaning liquid in the cleaning tank other than the final stage may contain an acid generated in the decomposition process by ozone, but the cleaning liquid in the final stage cleaning tank does not contain an acid. The cleaning liquid that remains thin does not contain acid, and the circuit pattern on the substrate surface can be prevented from corroding in the cleaning process with pure water in the next step.

  Here, the crystallization means includes a solidification pulverization part for solidifying and pulverizing the cleaning liquid continuously, a crystallization part for crystallization while continuously dissolving the pulverized product, and a liquefaction for liquefying a crystal body by crystallization. May be included.

According to this configuration, the cleaning liquid can be regenerated by crystallization continuously and efficiently.
The cleaning method and the semiconductor manufacturing apparatus of the present invention also have the same means as described above.

  As described above, according to the cleaning apparatus of the present invention, there is an effect that the cleaning liquid can be used semipermanently and the replacement of the cleaning liquid can be made unnecessary. In practice, it is only necessary to replenish the reduction amount that remains thinly on the substrate and is exhausted during the cleaning process.

  Further, the cleaning liquid can be regenerated continuously during operation without stopping the cleaning device, and the substrate can be efficiently cleaned.

  Furthermore, corrosion of the circuit pattern on the substrate surface can be prevented or reduced in the cleaning process with pure water in the next process.

(Embodiment 1)
A cleaning apparatus according to an embodiment of the present invention is an apparatus for cleaning a substrate such as a glass substrate of a liquid crystal panel, a glass substrate of a PDP (plasma display panel), or a semiconductor wafer, and a semiconductor for manufacturing a liquid crystal panel, a PDP, or a semiconductor. It is installed as a process of manufacturing equipment. This cleaning apparatus uses ethylene carbonate as a cleaning liquid, regenerates the cleaning liquid by ozone ventilation, and also regenerates the cleaning liquid by crystallization. The cleaning solution can be used semi-permanently, eliminating the need to change the cleaning solution. Here, crystallization means that crystals are precipitated from the liquid phase, thereby separating specific components (impurities) from the liquid phase. The cleaning liquid is ethylene carbonate (EC), propylene carbonate (PC), or a mixture thereof.

  Ethylene carbonate (melting point: 36.4 ° C., boiling point: 238 ° C., flash point: 160 ° C.) is a colorless and odorless solid at room temperature and needs to be heated to be used as a cleaning liquid, but can be used as an aprotic polar solvent. High boiling point, flash point, and low toxicity. As the cleaning liquid, first, the organic film has excellent peeling performance (fast peeling speed), and secondly, it is easy to decompose the resist dissolved in the liquid without reacting with ozone. And third, it has the property of being water-soluble (neutral).

  Propylene carbonate (melting point −48.8 ° C., boiling point 242 ° C., flash point 160 ° C. or higher) is almost the same in the first to third points. However, propylene carbonate has a demerit that it is slightly inferior in detergency at the first point and slightly affected by ozone at the second point as compared with ethylene carbonate. There is a merit that it can be easily used as a cleaning liquid without having to do so.

  FIG. 1 is a diagram illustrating a configuration of a cleaning device according to the first embodiment. In the figure, the cleaning apparatus 1 includes a carry-in tank 2, a cleaning tank 3, a cleaning tank 4, a relay tank 5, a cleaning tank 6, a tank 7, a tank 8, a tank 9, a unidirectional connecting pipe 9b, a first regeneration unit (hereinafter referred to as “recycler”). An ozone ventilation section) 10, a second regeneration section (hereinafter referred to as a crystallization section) 11, and piping for circulating the cleaning liquid are provided.

  The carry-in tank 2 is a carry-in port for the glass substrate of the liquid crystal panel, and has an air tube A. The air tube A is also called an air knife, and sprays compressed air in the direction of the cleaning tank 3 in order to prevent the cleaning liquid on the substrate from flowing backward from the cleaning tank 3 to the carry-in tank 2.

  The cleaning tank 3 has nozzle tubes B to G and air tubes H and I, and performs the first stage cleaning on the substrate transferred from the loading tank 2. The nozzle tubes B to G eject the cleaning liquid supplied from the tank 8 onto the surface of the glass substrate. Thereby, the glass substrate to which the resist is attached is cleaned in the first stage by the cleaning liquid ejected from the nozzle tubes B to G. The cleaning liquid at this time is supplied from the tank 8. That is, the cleaning liquid in the tank 8 is supplied via the supply pipe 12, the pump 13, the filter F 2, the supply pipe 14, the floating flow meter 15, and the supply pipe 16 as a piping path for supplying the cleaning liquid from the tank 8 to the cleaning tank 3. It is supplied to the nozzle tubes B to G. The air tubes H and I are air knives, and drop the cleaning liquid on the glass substrate into the cleaning tank 3 by ejecting the compressed air supplied from the air compressor onto the glass substrate. The cleaning liquid that has flowed down from the glass substrate is supplied from the cleaning tank 3 to the ozone ventilation unit 10 through the discharge pipe 17, the tank 7, the discharge pipe 18, the pump 19, and the discharge pipe 20.

  The tank 7 has a heater 7 a, temporarily stores the cleaning liquid discharged from the cleaning tank 3 through the discharge pipe 17, and discharges it to the ozone ventilation section 10 through the discharge pipe 18, the pump 19, and the discharge pipe 20. It is a buffer tank. The heater 7a warms the cleaning liquid. When the cleaning liquid is ethylene carbonate, the temperature is 40 ° C. to 200 ° C., and when the cleaning liquid is propylene carbonate, the temperature is within the range of room temperature to 200 ° C. This is because ethylene carbonate (melting point: 36.4 ° C.) is solid at room temperature and thus liquefies.

  The cleaning tank 4 includes nozzle tubes J to O and air pipes P and Q, and performs the second stage cleaning on the substrate conveyed from the cleaning tank 3. The nozzle tubes J to O eject the cleaning liquid supplied from the tank 9 onto the surface of the glass substrate. Thereby, the glass substrate after washing | cleaning by the washing tank 3 is wash | cleaned with the washing | cleaning liquid ejected from nozzle tube JO. The cleaning liquid at this time is supplied from the tank 9. That is, the cleaning liquid in the tank 9 is supplied via the supply pipe 24, the pump 25, the filter F 1, the supply pipe 26, the floating flowmeter 27, and the supply pipe 28 as a piping path for supplying the cleaning liquid from the tank 9 to the cleaning tank 4. Supplied to nozzle tubes JO. The air tubes P and Q are the same as the air tubes H and I described above. The cleaning liquid flowing down from the glass substrate is discharged from the cleaning tank 4 to the tank 8 through the discharge pipe 30.

  The tank 8 has a heater 8 a and a level sensor 8 b that measures the amount of liquid, and collects the cleaning liquid from the cleaning tank 4 through the discharge 30. The heater 8a is the same as the heater 7a. When the liquid amount measured by the level sensor 8b is reduced from the set liquid amount L by a control unit (not shown), a new cleaning liquid is supplied from the new cleaning liquid supply pipe 34 to the tank 9, and when the set liquid amount H is reached, the supply is stopped. Is done.

The relay tank 5 conveys the glass substrate carried out from the cleaning tank 4 to the cleaning tank 6.
The cleaning tank 6 includes nozzle tubes R to V and an air tube W, and cleans the glass substrate carried out from the relay tank 5 with pure water.

  The tank 9 has a heater 9a, collects the cleaning liquid regenerated by the ozone ventilation section 10 via the discharge pipe 21, the branch valve 22, and the supply pipe 23, and supplies the cleaning liquid regenerated by the crystallization section 11 to the supply pipe 32. Then, it is recovered through the valve 33. The heater 9a is the same as the heater 7a.

  The unidirectional connecting pipe 9b supplies the cleaning liquid from the tank 9 to the tank 8 in one direction when the amount of the cleaning liquid in the tank 9 exceeds a specified amount.

  The first regeneration unit (ozone ventilation unit) 10 regenerates the cleaning liquid by ventilating ozone from the tank 7 through the discharge pipe 18, the pump 19, and the discharge pipe 20.

  The second regeneration unit (crystallization unit) 11 acquires a part (for example, 10%) of the cleaning liquid supplied from the ozone ventilation unit 10 via the discharge pipe 21 from the branch valve 22 and crystallizes impurities by crystallization. Separate and regenerate the cleaning solution to high purity.

  Thus, the cleaning apparatus 1 performs two-stage cleaning in the cleaning tank 3 and the cleaning tank 4 in order to peel the organic film from the glass substrate to which an organic film such as a resist is adhered, and further thinly remains on the surface of the substrate. In order to flow the cleaning liquid to be cleaned, cleaning with pure water in the cleaning tank 6 is performed. The cleaning liquid in the first stage cleaning tank 3 is the cleaning liquid after the cleaning in the second stage cleaning tank 4. The cleaning liquid in the second-stage cleaning tank 4 is a cleaning liquid regenerated by the ozone ventilation unit 10 from the cleaning liquid after the first-stage cleaning, and a part of the cleaning liquid regenerated by the ozone ventilation unit 10 is further obtained. Regenerated by the crystallization part 11. That is, the cleaning liquid is circulated from the subsequent cleaning tank 4 to the preceding cleaning tank 3, and the cleaning liquid in the final cleaning tank 4 is in the cleanest state.

  FIG. 2 is a diagram illustrating a more detailed configuration example of the crystallization unit 11. In the figure, the crystallization unit 11 includes a drum flaker 11a, a belt conveyor 11b, a crystal purification device 11c, a tank 11d, a pump 11e, and a filter F3.

  The drum flaker 11a continuously cools and solidifies the cleaning liquid discharged from the supply pipe 31 and pulverizes it. As a result, ethylene carbonate powder (hereinafter referred to as powder) solidified into crude crystals is continuously produced. The melting point of ethylene carbonate is 36.4 ° C, and this cooling and solidification only makes the temperature lower than 36.4 ° C, so that it can be easily solidified at room temperature.

  The belt conveyor 11b conveys the powder produced by the drum flaker 11a and continuously supplies it to the crystal refiner 11c.

  The crystal refining device 11c separates impurities by crystallization of the powder and purifies it with high purity. In this crystallization, impurities are discharged from the crystal of ethylene carbonate by a so-called sweating phenomenon.

  The tank 11d has a heater and is liquefied by heating the powder from which impurities are removed and purified to a high purity with the heater.

  The pump 11 e supplies the regenerated cleaning liquid from the tank 11 d to the tank 9 through the supply pipe 32.

  FIG. 3 is a block diagram showing a detailed configuration example of the crystal purification apparatus 11c. In the figure, the crystal purification device 11c includes a cylinder 150, a feeder 151, a liquid separator 152, a receiving port 153, a transfer screw 154, a screw conveyor 155, a melting device 156, an outlet 157, a waste port 158, and a heater 159.

  The coarse crystal powder conveyed from the belt conveyor 11 b is continuously supplied as a raw material to the receiving port 153, and further transferred to the lower part in the cylindrical body 150 by the transfer screw 154 in the feeder 151. Powder is conveyed upward while being loosened by a screw conveyor 155 with special blades rotating at a low speed, and in the process, it is repeatedly compressed and released in conjunction with the movement of the blades, and purified by sweating in a solid-liquid equilibrium state. Is done. In other words, when the powder crystals are maintained at a temperature close to the melting point, the impurities contained therein are discharged by sweating. Furthermore, a part of the powder that has reached the top of the tower is melted by a melting device 156 installed at the upper portion, and becomes a reflux liquid and flows down in the cylindrical body 150. This reflux liquid raises the temperature of the crystal by coming into contact with the crystal and promotes the sweating phenomenon to discharge the impurities inside the crystal to the surface, and by washing the crystal surface of the powder by contacting with the crystal, the impurities are concentrated. However, it flows in the lower part of the cylinder 150. The liquid separator 152 in the lower part of the cylindrical body 150 discharges the liquid containing the concentrated impurities from the waste outlet 158. The heater 159 heats the cylindrical body 150 to a temperature close to the melting point but does not reach the melting point.

  As a result, most of the powder that has reached the top of the tower from the lower part of the cylindrical body 150 by the screw conveyor 155 is purified to an extremely high purity in the process of being conveyed and is carried out from the outlet 157. In addition, since a part of the reflux liquid is recrystallized before reaching the lower part of the column, it can be purified to a crystal having a very high yield and a purity of almost 100%.

  As described above, the crystal purification device 11c promotes the separation of impurities, the cleaning of the crystal surface, heat transfer, and mass transfer by stirring, and efficiently purifies with a short residence time. The crystal purification device 11c includes, for example, Kureha Crystal Purifier (KCP) manufactured by Kureha Techno Engineering Co., Ltd.

  FIG. 4 is a block diagram illustrating a detailed configuration example of the ozone ventilation unit 10. The ozone ventilation unit 10 mainly performs resist decomposition by ozone gas ventilation and ozone deaeration by nitrogen gas ventilation. In the figure, the ozone ventilation unit 10 is configured so that the cleaning liquid passes through the cleaned cleaning liquid discharged from the tank 7 through the discharge pipe 18, the pump 19, and the discharge pipe 20 and taken in from the stock solution intake pipe 101. A stock solution tank 100 that stores the stock solution, a stock solution pump 102 that sucks the stock solution from the stock solution tank 100 and sends it to the first aeration treatment pipe 104 via the check valve 141, the valve 140, and the floating flowmeter 103, and a supply from the stock solution pump 102 A first aeration treatment tube 104 that aerates ozone gas into the undiluted solution, a second aeration treatment tube 106 that aerates ozone gas from the first aeration treatment tube 104 through the connecting tube 105, and a second aeration treatment. A degassing treatment tube 10 for degassing ozone gas by ventilating nitrogen gas from a tube 106 through a connecting tube 107 to a cleaning solution. When, and a processing liquid tank 110 to accumulate the cleaning liquid supplied through the connecting pipe 109 from the degassing process tube 108 as the processing liquid.

  The heater 142 and the cooling pipe 122 in the undiluted liquid tank 100 are for adjusting the temperature so that the undiluted liquid does not solidify and has a temperature suitable for regeneration.

  The cooling pipe 122 in the stock solution tank 100 cools the stock solution with cold water supplied from the outside via the cold water intake pipe 121 and drains it outside through the cold water discharge pipe 123.

  A cooler 119 attached around the first aeration treatment tube 104 cools the first aeration treatment tube 104 with cold water supplied from outside via a cold water intake tube 118, and externally passes through a cold water discharge tube 120. Drain into. Thereby, the solubility of ozone gas is increased, the decomposition of the ozone gas is prevented, and the temperature is maintained at an appropriate temperature that promotes the decomposition of the resist by aeration of ozone gas.

  In addition, the flow rate of the stock solution pump 102 is adjusted according to the liquid level measured by the level sensor 144 by a control unit (not shown).

  The heater 132 warms the cleaning liquid after regeneration and deaeration to about 80 ° C., for example. The heater 132 is adjusted by the temperature measured by the thermometer 133.

  The laser sensor 130 measures the resist color concentration of the cleaning solution after ozone regeneration that bypasses the bypass pipe 129 and the bypass pipe 131 by the four-way valve 128. The cleaning solution is colorless and transparent when the resist is not dissolved, but becomes darker, orange and brown as the solubility of the resist increases. Since the cleaning liquid after regeneration is normally transparent, the resist color concentration measured by the laser sensor 130 is used for determining whether or not an abnormality has occurred in the ozone gas system, the cleaning liquid circulation system, or the like.

  The processing liquid in the processing liquid tank 110 is discharged into the tank 8 as a regenerated cleaning liquid through the discharge rod 21, the branch valve 22, and the supply pipe 23 shown in FIG.

  Regarding the configuration relating to the ozone gas in the ozone ventilation section 10, the ozone gas sent out by the ozone gas generator (not shown) is supplied from the ozone intake pipe 114 to the second ventilation treatment pipe 106, and the first ventilation treatment is performed via the ozone pipe 115. It is supplied to the pipe 104 and further ventilated into the stock solution tank 100 through the ozone pipe 116.

  Regarding the configuration related to the nitrogen gas in the ozone ventilation section 10, the nitrogen gas sent out by a nitrogen gas cylinder (not shown) is supplied to the deaeration treatment pipe 108 through the nitrogen intake pipe 124, and the stock solution tank is passed through the nitrogen intake pipe 125. 100 is discharged. Here, an inert gas called nitrogen gas is used, but air or other gas (gas) may be used.

  The ozone gas and nitrogen gas supplied to the stock solution tank 100 are exhausted from the exhaust pipe 117 via the ozone decomposer 145.

  The heater 126 preheats the cleaning liquid flowing through the degassing processing tube 108 prior to heating of the cleaning liquid in the processing liquid tank 110. This preheating also serves as decomposition of ozone gas in the degassing treatment tube 108 and promotion of degassing. At this time, the heating amount is adjusted according to the temperature measured by the thermometer 127 by a control unit (not shown).

The ozone sensors 135 and 137 measure the concentration of ozone gas, respectively.
The ozonolysis device 145 decomposes ozone gas with a catalyst to render it harmless.

  FIG. 5A and FIG. 5B are explanatory views showing an example of a resist decomposition process by ozone ventilation. FIG. 5A shows a decomposition process of a general novolac resin as a main component of the resist. As shown in the figure, the novolak resin is decomposed into phenol and further decomposed into muconic acid and muconaldehyde. Muconic acid is degraded directly to glyoxylic acid or via maleic acid to glyoxylic acid. Also, muconaldehyde is decomposed directly into gliosar or via malealdehyde to gliosar. Glyoxylic acid and gliosal are broken down into formic acid and further broken down into carbon dioxide and water.

  FIG. 5B shows a decomposition process of naphthoquinonediaziso, which is a general photosensitizer (photocuring agent) contained in the resist. As shown in the figure, naphthoquinone diazio is decomposed into naphthalene, further decomposed into 2-ozonates, and further decomposed into phthalic acid via phthalaldehyde. Phthalic acid is broken down to gliosal, maleic acid, or mesoxalic acid. Gliosal is decomposed into formic acid, maleic acid is decomposed into formic acid via glyoxylic acid, and mesoxalic acid is decomposed into oxalic acid. Formic acid and oxalic acid are broken down into carbon dioxide and water.

  Although depending on the quantitative regeneration capability of the ozone ventilation part 10, impurities derived from the resist and acids generated in the decomposition process may remain as impurities in the cleaning liquid after the ozone ventilation. The crystallization unit 11 separates such impurities to make the cleaning liquid highly pure.

  As described above, according to the cleaning apparatus in the present embodiment, impurities dissolved in the cleaning liquid are separated by crystallization of the cleaning liquid, so that the cleaning liquid can be maintained at a high purity, and the cleaning liquid is semi-permanent. Can be used effectively, and there is an effect that it is not necessary to replace the cleaning liquid. Actually, it is only necessary to replenish the reduction amount that remains thinly on the substrate and is exhausted during the cleaning process.

  Furthermore, impurities that remain on the substrate surface and are taken to the next process can be reduced. Thereby, the corrosion of the circuit pattern on the substrate surface can be reduced in the cleaning process with pure water in the next process.

  Further, since the crystallization unit 11 continuously acquires at least a part of the cleaning liquid from the circulation path, crystallizes it, and returns it to the circulation path, the cleaning liquid can be regenerated during operation without stopping the cleaning apparatus. .

  Furthermore, since it is cleaned with a clean cleaning liquid at the later stage of the two cleaning tanks, it can be cleaned efficiently.

  It should be noted that the temperature of the drum flaker 11a in the crystallization unit 11 may be adjusted so as to be in a solid-liquid equilibrium state to cause a sweating phenomenon of crystallization.

  Further, the ratio of the cleaning liquid that the crystallization unit 11 acquires from the cleaning liquid supplied from the ozone ventilation unit 10 by the branch valve 22 may be determined according to the regeneration capability of the crystallization unit 11.

  In addition, you may make it return the liquid discarded from the disposal port 158 of the crystal | crystallization refiner | purifier 11c to the drum flaker 11a.

  FIG. 6 is a diagram illustrating a configuration of a modified example of the cleaning device. The cleaning device 160 shown in the figure is different from the cleaning device 1 shown in FIG. 1 in that one cleaning tank is added. As a result, the cleaning ability can be further increased while circulating and reusing the cleaning liquid.

(Embodiment 2)
In the cleaning apparatus according to the second embodiment, the cleaning liquid in the cleaning tanks other than the final stage contains acid generated in the decomposition process by ozone ventilation, but the cleaning liquid in the final stage cleaning tank contains only a very small amount of acid. It is composed. As a result, the cleaning solution that remains thinly on the substrate carried out from the final stage contains only a very small amount of acid, and the circuit pattern on the substrate surface is prevented from corroding in the cleaning process with pure water in the next step.

  FIG. 7 is a diagram illustrating a configuration of the cleaning device according to the second embodiment. The cleaning apparatus 1a of the figure is different from the cleaning apparatus 1 shown in FIG. Explanation of the same points is omitted, and different points will be mainly described below.

  The difference in the piping is that the cleaning liquid regenerated by the ozone vent 10 is not returned to the tank 9 for supplying the cleaning liquid to the final cleaning tank, but is supplied to the cleaning tanks other than the final stage. It is the point which is recirculating to 8. Therefore, the cleaning liquid regenerated by the ozone ventilation unit 10 is returned to the tank 8 through the discharge pipe 21 and the supply pipe 223. Further, a part of the cleaning liquid from the ozone ventilation unit 10 is supplied to the crystallization unit 11 through the valve 222 and the supply pipe 31, impurities are removed by crystallization in the crystallization unit 11, and refluxed to the tank 9. The

  With this configuration, the pipe line forms two circulation paths. One is a circulation path for circulating the cleaning liquid to the final-stage washing tank 4 and the final-stage tank 9, and circulates the cleaning liquid containing a very small amount of acid. The other is a circulation path for circulating the cleaning liquid to the cleaning tank other than the final stage and the tanks 8 and 7 other than the final stage, and the cleaning liquid containing more acid than the first circulation path is circulated. .

  As described above, according to the cleaning apparatus 1a in the second embodiment, since the cleaning liquid thinly remaining on the substrate carried out from the final stage contains only a very small amount of acid, cleaning with pure water in the next process is performed. During the process, acid corrosion of the circuit pattern on the substrate surface can be prevented.

  Note that the cleaning apparatus 1a shown in FIG. 7 is not limited to two stages, and a three-stage cleaning tank may be provided.

  In each of the above embodiments, the crystallization unit 11 always regenerates the cleaning liquid during operation of the cleaning device, but is not limited to being in operation. For example, it may be regenerated only by the ozone ventilation part 10 during operation, and may be regenerated by the crystallization part 11 during the rest, or may be intermittently regenerated by the crystallization part 11 according to the impurity concentration during operation. Alternatively, one crystallization unit 11 may be shared by a plurality of cleaning apparatuses.

  The present invention is suitable for a cleaning apparatus for removing or removing a resist in a process for manufacturing a liquid crystal panel or a semiconductor.

2 is a diagram illustrating a configuration of a cleaning device in Embodiment 1. FIG. It is a block diagram which shows the structure of a 2nd reproduction | regeneration part (crystallization part). It is a block diagram which shows the structure of a crystal purification apparatus. It is a block diagram which shows the structure of a 1st reproduction | regeneration part (ozone ventilation part). It is explanatory drawing which shows the decomposition | disassembly process of a resist. It is explanatory drawing which shows the decomposition | disassembly process of a resist. It is a figure which shows the structure of the modification of a washing | cleaning apparatus. It is a figure which shows the structure of the washing | cleaning apparatus in Embodiment 2. FIG. It is a figure which shows the structure of the washing | cleaning apparatus in a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cleaning device 2 Carry-in tank 3 Cleaning tank 4 Cleaning tank 5 Relay tank 6 Cleaning tank 7, 8, 9 Tank 10 Ozone ventilation part 11 Crystallization part

Claims (8)

Cleaning means for cleaning the substrate while circulating the cleaning liquid;
Crystallization means for regenerating by crystallization of the cleaning liquid;
A cleaning device comprising: supply means for supplying the cleaning liquid after regeneration to the cleaning means. The cleaning liquid contains either ethylene carbonate or propylene carbonate,
2. The cleaning apparatus according to claim 1, wherein the crystallization unit crystallizes a part of the cleaning liquid during cleaning by the cleaning unit. The cleaning device further includes ozone ventilation means for regenerating the cleaning liquid by ventilating ozone to the cleaning liquid after cleaning by the cleaning means, and refluxing the cleaning liquid after regeneration to the cleaning means,
The cleaning apparatus according to claim 1, wherein the crystallization unit crystallizes a part of the cleaning liquid refluxed by the ozone ventilation unit. The cleaning means has at least two cleaning tanks for cleaning the substrate in stages,
The cleaning device has a circulation means for circulating the cleaning liquid used in the subsequent cleaning tank as the cleaning liquid in the previous cleaning tank,
The ozone aeration means regenerates the used cleaning liquid in the first-stage cleaning tank by ozone ventilation, and returns the regenerated cleaning liquid to the last-stage cleaning tank,
4. The cleaning apparatus according to claim 3, wherein the supply means supplies the cleaning liquid after regeneration by crystallization to a final-stage cleaning tank. The cleaning means has at least two cleaning tanks for cleaning the substrate in stages,
The cleaning device has a circulation means for circulating the used cleaning liquid in the final stage cleaning tank to the final stage, and circulating the used cleaning liquid in the cleaning tank other than the final stage to the cleaning tank other than the final stage,
The ozone ventilation means regenerates the used cleaning liquid in the cleaning tank other than the final stage by ozone ventilation and returns it to the cleaning tank other than the final stage,
4. The cleaning apparatus according to claim 3, wherein the supply means supplies the cleaning liquid after regeneration by crystallization to a final-stage cleaning tank. The crystallization means is
A solidified and pulverized section for continuously solidifying and pulverizing the cleaning liquid;
A crystallization part that crystallizes while continuously dissolving the pulverized product,
6. A cleaning apparatus according to claim 2, further comprising a liquefaction unit for liquefying a crystal body by crystallization. A cleaning step for cleaning the substrate while circulating the cleaning liquid in the cleaning tank;
A crystallization step for regenerating by crystallizing the cleaning liquid;
A supply step of supplying the cleaning liquid after regeneration to the cleaning tank.   A semiconductor manufacturing apparatus comprising the cleaning apparatus according to claim 1.

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