JP2005169342A - Regenerator and regenerating method of organic coating washing liquid and washing device and washing method of organic coating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a removing method and removing device of an organic coating which enable the regeneration of the solvency of the organic coating of a washing liquid containing ethylene carbonate as an active ingredient and uses the same for circulation as the washing liquid and is capable of regenerating the same without using ozone. <P>SOLUTION: A crystallization regenerator of the organic coating washing liquid which has a washing tank for receiving the washing liquid containing the ethylene carbonate as the active ingredient, a crystallization means for precipitating an ethylene carbonate crystal by cooling down the washing liquid dissolving the organic coating transferred from the washing tank, a heating means for liquefying the ethylene carbonate separated in the crystallization means by heating, a circulation means for transferring the ethylene carbonate liquefied by the heating means to the washing tank for circulation via the crystallization means and the heating means from the washing tank, and which is capable of recycling the ethylene carbonate as the washing liquid is provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an organic film cleaning liquid crystallization regeneration apparatus and a crystallization of an organic film cleaning liquid that can purify the contaminated cleaning liquid by dissolving the organic film in cleaning using a cleaning liquid containing ethylene carbonate as an active ingredient. It relates to a playback method. Furthermore, the present invention relates to an ethylene carbonate crystallization apparatus suitable for use as a crystallization means for an organic coating film cleaning apparatus, a cleaning method, and a regeneration apparatus using the same.

  The manufacturing process of a semiconductor wafer is performed through various application processes such as application of a resist to the entire surface of the semiconductor wafer. At this time, the application of the resist is performed by forming a resist film having a predetermined film thickness on the wafer surface by rotating the wafer by a spin coater while shaking off the resist dropped on the center of the wafer by centrifugal force.

  The spin coating method is used not only for resist coating but also for SOG coating for forming an SOG (Spin On Glass) film. That is, by controlling the rotation of the wafer fixed to the turntable and shaking off the SOG liquid dropped on the center of the wafer, an SOG having a predetermined film thickness can be formed in the same manner as resist coating.

  In such a spin coating method, the shaken coating material falls into a drain cup (spin coater cup) and is collected, discharged from the drain, and guided to another processing tank.

  However, in any of the above-described coating processes, by repeating this, the remaining resist deposit without being discharged from the drain is gradually accumulated in the spin coater cup. When this deposit increases, there is a concern about the influence of particles in the wafer process. Therefore, at the time of maintenance, it is necessary to clean the spin coater cup and remove the remaining deposits, and cleaning is performed by supplying an organic solvent such as ethylene glycol or thinner, or ozone water (for example, Patent Documents). 1).

  Further, although it is used for cleaning a wafer instead of a spin coater cup, 4-methoxy-1-butanol, 3-methoxy-1-butanol, or 4-methoxy is also used for removing and removing the resist coating film. A stripping composition for a photoresist composed of a solvent composed of a mixture of -1-butanol and 3-methoxy-1-butanol and propylene carbonate (see, for example, Patent Document 2), 40 to 50% by volume. Photo in an ultrasonic stirring bath of a solvent containing aprotic / cyclic carbonate such as ethylene carbonate and protic polar compounds such as ethylene diacetate and ethylene dibutyrate, and N-methyl-2-pyrrolidone and triethanolamine. A method for removing the resist (for example, see Patent Document 3) and a treatment liquid in which ozone gas is dissolved are used. As a method for removing the organic coating, a solution containing one or more organic solvents in which the partition coefficient between ethylene carbonate and ozone in the gas is 0.6 or more at room temperature and is difficult to be decomposed by ozone. There is known a method using (see, for example, Patent Document 4).

In contrast, the applicant found that ethylene carbonate or propylene carbonate alone can sufficiently remove and remove the resist, and after removing the organic film with ethylene carbonate, the dissolved organic film is reduced in molecular weight by ozone. A patent application has already been filed for a method of removing an organic coating that decomposes into a substance, regenerates it as a treatment liquid, and circulates it (Japanese Patent Application No. 2002-229394).
Japanese Patent Laid-Open No. 2002-205021 Japanese Patent No. 2679618 US Pat. No. 5,690,747 JP 2003-282518 A

  Therefore, the present invention regenerates the ability to dissolve the organic film of ethylene carbonate, which is contaminated and reduced by dissolving the organic film when using a cleaning solution containing ethylene carbonate as an active ingredient as a solvent for resist stripping. An object of the present invention is to provide an organic film cleaning liquid crystallization regeneration method and an organic film cleaning liquid crystallization regeneration apparatus which can circulate and use ethylene as a cleaning liquid without using ozone.

  The organic film cleaning liquid crystallization regeneration apparatus of the present invention cools a cleaning tank containing a cleaning liquid containing ethylene carbonate as an active ingredient and an organic film transferred from the cleaning tank to precipitate ethylene carbonate crystals. Crystallization means, heating means for heating ethylene carbonate obtained by the crystallization means to make it liquid, and transfer of ethylene carbonate liquefied by the heating means from the washing tank to the washing tank via the crystallization means and heating means And circulating means for circulating.

  The organic coating film cleaning apparatus of the present invention is an organic coating film cleaning liquid crystallization regeneration apparatus according to any one of claims 1 to 5 and an organic coating film cleaning liquid crystallization regeneration apparatus, after which the organic coating film is removed and rinsed with the cleaning liquid. And a drying means for drying the adhering pure water after washing in the pure water washing tank.

  The organic film cleaning liquid crystallization regeneration method of the present invention includes a cleaning process of removing an organic film with a cleaning liquid containing ethylene carbonate as an active ingredient, and cooling the cleaning liquid in which the organic film has been dissolved in the cleaning process to precipitate ethylene carbonate crystals. The crystallization step, the heating step to heat the ethylene carbonate obtained in the crystallization step, and the washing step, and the washing step to wash the ethylene carbonate liquefied by the heating step through the crystallization step and the heating step And a circulation process for circulating the process.

  The organic film cleaning method of the present invention comprises rinsing an object to be cleaned, from which the organic film has been removed by the cleaning step in the method for crystallizing and regenerating an organic film cleaning liquid according to any one of claims 8 to 13, with pure water. And a pure water cleaning step for washing away the adhering cleaning liquid, and a drying step for evaporating and drying the water adhering in the pure water cleaning step.

  According to the crystallization regeneration apparatus and the crystallization regeneration method of the organic coating film cleaning liquid of the present invention, the organic coating adhered to the object to be cleaned can be efficiently peeled and dissolved, and the organic coating is dissolved and contaminated. By recrystallizing and purifying the ethylene carbonate, the ability to dissolve the organic film of ethylene carbonate can be regenerated. Thus, the cleaning operation can be continuously performed for a long time without replacing the cleaning liquid.

  Further, according to the organic coating film cleaning apparatus and cleaning method of the present invention, the same effects as the organic coating film cleaning apparatus and cleaning method of the present invention can be obtained, and the cleaning liquid can be rinsed and dried in a series of operations. Can do.

  The organic film cleaning liquid crystallization regeneration apparatus and organic film cleaning liquid crystallization regeneration method according to the present invention will be described below with reference to the drawings.

[Organic film cleaning liquid crystallization regeneration apparatus and crystallization regeneration method]
(First embodiment)
FIG. 1 is a schematic view showing a first embodiment of an apparatus for crystallizing and regenerating an organic coating film cleaning liquid according to the present invention.

  The organic film cleaning liquid crystallization regenerating apparatus 1 of the present invention is a crystallization system for cooling a cleaning tank 3 containing a cleaning liquid 2 containing ethylene carbonate as an active ingredient and a cleaning liquid 2 in which the organic film transferred from the cleaning tank 3 is dissolved. Means 4; heating means 5 for heating ethylene carbonate taken out as crystals from crystallization means 4 to make it liquid; and carbonic acid liquefied by heating means 5 from washing tank 3 via crystallization means 4 and heating means 5 It comprises a circulating means 6 for transferring ethylene to the washing tank 3 for circulation. In addition, a resist concentration tank 7 is provided for storing the residual liquid when the resist-containing residual liquid becomes a high concentration by the crystallization means 4.

  The cleaning tank 3 used in the organic film cleaning liquid crystallization regeneration apparatus 1 contains a cleaning liquid 2 containing ethylene carbonate as an active ingredient, and the object to be cleaned is immersed in the cleaning liquid stored in the cleaning tank 3. In this way, the organic film adhering to the object to be cleaned is peeled off and removed.

  At this time, in order to remove the organic film more efficiently, it is preferable to swing the object to be cleaned while immersing it in the cleaning liquid or to irradiate the object to be cleaned with ultrasonic waves.

  FIG. 2 is a conceptual diagram of a swinging device that swings a cleaning basket into which an object to be cleaned is placed. As shown in FIG. 2, the oscillating device 21 is connected to the holding unit 23 for holding the cleaning basket 22 for immersing the object to be cleaned in the cleaning liquid, and is rotated by being connected to the holding unit 23. The cleaning basket 22 is composed of a cam 24 that can swing.

  In the case of irradiating ultrasonic waves, an ultrasonic vibrator is disposed on the bottom surface and / or side surface of the cleaning tank 3 so that the object to be cleaned in the cleaning tank 3 can be irradiated with ultrasonic waves. That's fine.

  The crystallization means 4 used in the organic film cleaning liquid crystallization regenerating apparatus 1 may be any crystallization means capable of performing partial cooling in order to separate ethylene carbonate from ethylene carbonate in which organic matter is dissolved. More specifically, the crystallization means includes, for example, a crystallization means capable of crystallizing ethylene carbonate on the drum surface by cooling the cleaning liquid with a drum as shown in FIGS.

  FIG. 3 is a perspective view showing a more specific outline of the structure of the crystallization means used in the present invention, and FIG. 4 is a sectional view of the drum as viewed from the axial direction.

  The crystallization means 41 shown in FIGS. 3 and 4 is disposed so that a cleaning liquid storage tank 411 that stores the cleaning liquid used for cleaning the organic coating and a part of the cleaning liquid stored in the cleaning liquid storage tank 411 are immersed in the crystallization means 41. And a horizontal cylindrical rotatable drum 412 that can cool itself, and a scraper 413 that is in contact with the surface of the drum 412 and can scrape off the ethylene carbonate crystals attached to the surface of the drum 412. ing. At this time, in order to keep the cleaning liquid in a liquid state, a heating unit for heating the bottom of the cleaning liquid storage tank 411 may be provided.

  The cleaning liquid storage tank 411 is used for cleaning the organic coating, can store the cleaning liquid transferred from the cleaning tank 3, and can contact the horizontal cylindrical drum 412 with the cleaning liquid stored therein. Any shape may be used as long as the drum 412 can be effectively brought into contact with the cleaning liquid, but a horizontal cylinder that is slightly larger than the drum 412 is cut in half in the axial direction of the cylinder. The container is preferably a semicircular container, and this may be disposed along the drum 412.

  The drum 412 has a horizontal cylindrical outer shape, and has a cooling medium therein, so that the drum itself is cooled. The cooling medium is not limited as long as it satisfies the inside of the drum, but a liquid is preferable from the viewpoint of cooling efficiency and ease of handling. For example, it is possible to sufficiently cool the cleaning liquid by introducing cooling water from the cooling water inlet 414 and discharging excess cooling water from the cooling water outlet 415 and continuing to flow the cooling water.

  The scraper 413 scrapes off the ethylene carbonate crystals adhering to the surface of the drum 412 when the drum 412 is cooled, so that one side of the scraper 413 is in contact with the surface of the drum and the side opposite to the side in contact with the drum. It is provided with an inclination so as to become lower toward the center. The crystal scraped by the scraper 413 rolls down the surface of the scraper 413 along the inclination and falls from the end of the scraper. The fallen ethylene carbonate crystals are introduced into the heating means to be liquid ethylene carbonate.

  The ethylene carbonate crystals obtained by the crystallization means 4 become liquid ethylene carbonate by being heated by the heating means 5 for melting them, and the purified ethylene carbonate is regenerated to regenerate the ability to dissolve the organic film. Can be reused in the cleaning liquid.

  The heating means 5 can be achieved by using a heater, and the temperature of the heating means is preferably 40 to 80 ° C.

  Further, the ethylene carbonate liquid obtained by crystallization once by the crystallization means 4 and the heating means 5 is further configured to be crystallized and melted by the crystallization means 4 and the heating means 5, that is, It is preferable that a plurality of combinations of crystallization means and heating means are provided and crystallization and melting are continuously repeated to obtain a crystal with high purity.

  In addition, crystallization of the ethylene carbonate may be carried out either continuously or batchwise by the crystallization means at this time, but as the ethylene carbonate crystals are removed, the cleaning liquid is concentrated and the concentration of organic matter increases. Therefore, it is preferable to continuously supply the cleaning liquid.

  The circulation means 6 used in the present invention is for transferring the ethylene carbonate liquefied by the heating means 5 from the washing tank 3 via the crystallization means 4 and the heating means 5 to the washing tank 3 for circulation. The ethylene carbonate present in the cleaning liquid in the cleaning tank 3 is cleaned and circulated to the cleaning tank 3.

  As long as this circulation means 6 can make a flow so that ethylene carbonate can circulate in order of the washing tank 3, the crystallization means 4, the heating means 5, and the washing tank 3, any of the circulation paths It may be arranged at a position, and a plurality may be provided in order to smoothly perform this circulation.

  Examples of the circulating means 6 for producing the liquid ethylene carbonate flow include a pump. The ethylene carbonate liquefied and regenerated by the heating means 5 by the action of the circulating means 6 is supplied to the washing tank 3. It is sent and used again for cleaning the organic coating.

  Next, a method for crystallizing and regenerating an organic coating film cleaning liquid using this organic coating film cleaning liquid crystallization regeneration apparatus will be described.

  In the method for crystallizing and regenerating an organic coating film cleaning liquid of the present invention, first, an organic substance adhering to the cleaning object is immersed in a cleaning tank 3 containing a cleaning liquid 2 containing ethylene carbonate as an active ingredient. A cleaning process for removing the film is performed.

  The cleaning liquid 2 used in the present invention contains ethylene carbonate as an active ingredient, and it is preferable to use ethylene carbonate alone. Since the dissolution ability of ethylene carbonate decreases as the resist dissolves, 80 mass of ethylene carbonate is used. % To a range containing 20% by mass or less of a resist component.

  Ethylene carbonate has a melting point of 36.4 ° C., a boiling point of 238 ° C., a flash point of 160 ° C., is easily soluble in water, is a colorless and odorless and relatively stable solid at room temperature, but is heated to a liquid aprotic polar solvent. It can be used as a substance. It is preferable because it has a high boiling point / flash point, low toxicity, and is not designated as a dangerous substance in the Fire Service Act.

  The ethylene carbonate liquid used here has a strong solubility in aromatic hydrocarbons, but the solubility parameter (SP value) related to the molecular cohesive energy density is as large as about 14, and theoretically, the solution is more likely to dissolve as the SP value is even. Therefore, the SP value of the polymer of the resist material is often around 10 and the stripping solvent has a similar value, for example, NMP having an SP value of 11 has been used.

  However, the present inventors have found that an ethylene carbonate solution can be peeled off at the same level or higher than that of a conventional peeling solvent. The dissolving action of the ethylene carbonate liquid on the organic coating becomes stronger as the temperature becomes higher, and can be safely operated at a temperature below the flash point. In an inert gas, even wet processing at about 200 ° C. There is no problem, and the vapor pressure at about 70 ° C. is about 1/10 compared with other organic solvent resist removers, and there is an advantage that liquid loss due to evaporation in heat treatment is small. At high temperatures, the amount of evaporation is slightly higher, but the toxicity of vapor is so low that it is not a problem.

  For example, since a novolak resist, which is a typical positive photoresist, is composed of a cresol polymer and a polycyclic aromatic, the solubility can be increased by heating if the cleaning liquid of the present invention is applied. .

  The effective temperature range by heating is 40 to 200 ° C., preferably 60 to 150 ° C. below the flash point. If the processing conditions are appropriate, a peeling rate of 20 μm / min or more can be easily obtained.

Even a novolac resist film that has been altered by 1 ⁺ 10 ¹⁵ / cm ² ion implantation of B ⁺ , which has been very difficult to remove by conventional wet stripping methods, can be achieved in a considerably short time by immersion treatment with a high-temperature ethylene carbonate solution. Can be peeled off. For example, the same applies to a resist in which a film having a thickness of 1.5 μm is peeled off by immersion in ethylene carbonate at 120 ° C. for 70 seconds and an altered layer is formed by dry etching.

  In addition, the higher the processing temperature, the lower the surface tension and viscosity, which is suitable for resist stripping in an ultrafine pattern device.

In the case of a B ⁺ 1 × 10 ¹⁴ / cm ² ion-implanted film, the 15 μm-thick peeling is 5 seconds when immersed in an ethylene carbonate solution at 120 ° C. (peeling speed: 18 μm / min), and 10 seconds when immersed at 100 ° C. (Peeling speed: 9 μm / min) and extremely fast. In the high-temperature treatment of a strongly altered resist, a peeling mechanism works in which components other than the surface layer portion that is particularly severely altered are easily dissolved in the cleaning liquid, and the altered components that are difficult to dissolve become fine particles and are dispersed in the liquid. The dispersed fine particles can be completely dissolved by subjecting the ethylene carbonate liquid to ozone gas ventilation treatment.

  Since the dissolving power at this high temperature is extremely large, the dissolution starts immediately by simply bringing the cleaning object having the organic film into contact with the cleaning liquid. Since the dissolution is a kind of diffusion phenomenon and becomes faster as the concentration difference is larger, the organic coating can be continuously dissolved by the convection of the cleaning liquid in the cleaning tank, and the dissolution effect can be maintained in a high state.

  As described above, when a liquid ethylene carbonate solution is used, an organic coating such as a resist film can be effectively peeled and removed, and the components derived from the organic coating are dissolved (and dispersed) in the cleaning solution after the treatment. It will be contained.

  In this cleaning process, since the power to dissolve the organic film of the ethylene carbonate liquid is large as described above, it is easy to peel and remove the organic film only by immersing the object to be cleaned. Further, in order to peel and remove the organic film more efficiently, the object to be cleaned may be rocked or irradiated with ultrasonic waves.

  Although the configuration of the swing device 21 in FIG. 2 has already been described, the operation of the oscillating device 21 is that the holding means 23 also starts circular movement as the cam 24 rotates, and the washing basket 22 connected to the holding means 23 is also moved to it. Accordingly, the movement is performed while drawing a circle in the vertical and horizontal directions, and the cleaning basket 22 is swung in the cleaning liquid 2 so that the organic coating can be peeled off more efficiently than just immersing the cleaning basket 22. is there.

  Further, when irradiating ultrasonic waves, an ultrasonic vibrator, for example, an ultrasonic vibrator of 28 kHz, 300 W is provided on the bottom surface and / or the side surface of the cleaning tank 3, thereby irradiating the ultrasonic wave to the object to be cleaned. By doing so, vibration is given to the organic film adhering to the object to be cleaned, and peeling of the organic film can be promoted. The cleaning liquid 2 in which the component derived from the organic coating is dissolved is transferred from the cleaning tank 3 to the crystallization means 4 and subjected to the crystallization process.

  As a crystallization process here, the case where the crystallization means 41 shown in FIG.3 and FIG.4 is used is demonstrated.

  Cooling in the crystallization step is performed by immersing a part of the drum 412 in the cleaning liquid 2 transferred from the cleaning tank 3 to the cleaning liquid storage tank 411, so that the drum 412 cooled from the contacted part can heat the cleaning liquid 2. This is done by transferring this heat to the cooling medium inside the drum. Therefore, if the inside of the drum is sealed, the temperature of the cooling medium rises and the cooling function is impaired as time passes. Therefore, it is necessary to always keep the drum in a cooled state.

  Therefore, this crystallization means is configured such that the drum 412 itself is always cooled by introducing a liquid as a cooling medium from one end of the rotating shaft and discharging the liquid introduced from the other end of the rotating shaft. . The cleaning liquid may have any solidification temperature depending on the contamination of the resist, and any drum can be used as long as it can maintain the drum 412 at a temperature lower than the solidification temperature of the cleaning liquid. By using this, the cooling function of the cleaning liquid can be sufficiently achieved.

For example, in the case of a drum having a diameter of 170 mm, a length of 300 mm, and a surface area of 1600 cm ² , the drum can be sufficiently maintained at a constant cooling temperature if the flow rate of cooling water is 60 L / hour. it can.

  By contacting with the cooled drum 412, the heat of the cleaning liquid stored in the cleaning liquid storage tank 411 is removed, and the ethylene carbonate in the cleaning liquid is crystallized. The crystallized ethylene carbonate adheres to the drum surface, and the adhering ethylene carbonate crystal is carried along with the rotation of the drum 412 and separated from the cleaning liquid. The cleaning liquid stored in the cleaning liquid storage tank 411 is constantly circulated by the circulation pump 416 so that the liquid concentration in the tank becomes uniform.

  At this time, in order for crystals to adhere to the drum surface, the drum must be sufficiently cooled to generate crystal nuclei on the drum surface, and further to grow crystals, so the drum rotates slowly at 5 to 50 rph. It is preferable that the rotation be performed. Further, the material of the drum surface must be attached with crystals, and examples thereof include a mirror-finished SUS material and a glass material having good heat conductivity.

  The ethylene carbonate crystals separated from the cleaning liquid reach the scraper 413 by the rotation of the drum 412 and are scraped off from the drum surface by the scraper 413. The scraper 413 is in contact with the drum surface on one side, so that the ethylene carbonate crystals adhering to the drum surface can be scraped cleanly from the drum surface, and hard rubber, elastomer, hard plastic, etc. so as not to damage the drum surface. It is made with.

  The ethylene carbonate crystal scraped off is placed on the upper surface of the scraper 413, but rolls down to the side opposite to the side used for scraping due to the inclination of the scraper 413. The rolled ethylene carbonate crystal is introduced into the heating means 5 and is subjected to a heating process. When heated by the heating means 5, the crystal melts to form liquid ethylene carbonate. In addition, when the scraper 413 does not roll off, the scraper itself can be used as a heating means. At that time, the ethylene carbonate liquid flows down from the scraper 413. Here, it is preferable that the temperature in a heating means is 40-80 degreeC.

  The ethylene carbonate liquefied in this step is then subjected to a circulation step, but before that, it is further configured to pass through a crystallization step and a heating step, that is, the crystallization step and heating. It is preferable to provide a plurality of combinations of steps and continuously perform crystallization and melting repeatedly in order to obtain crystals with high purity.

  The cleaning liquid can be used for dissolution until it contains up to about 20% by mass of organic substances constituting the organic coating. When this is purified by crystallization and melting once, the purity of ethylene carbonate is 90% and recovered. The rate is about 75%, and when crystallization is performed twice, the purity is 95% and the recovery rate is about 55%. In addition, the purity becomes higher each time the crystallization is repeated, but the recovery rate decreases. Therefore, it is preferable to perform crystallization and melting twice from the viewpoint of the cost of reuse when considering the purity and the recovery rate. .

  Although the illustration is omitted after scraping off the ethylene carbonate crystals with a scraper, in order to obtain a high purity ethylene carbonate solution, it is preferable to separate the cleaning solution adhering to the ethylene carbonate crystals in a small amount by solid-liquid separation means. Examples of the solid-liquid separation means include a filter cloth built-in rotary centrifuge. In addition, when performing solid-liquid separation, a scraper is not heated with a heating means.

  The circulation step is used in the washing step, and circulates the ethylene carbonate liquefied by the heating step through the crystallization step and the heating step to the washing step, whereby the ethylene carbonate present in the washing liquid of the washing tank 3 Is cleaned and circulated to the washing tank 3.

  This circulation step is a step of making a flow so that ethylene carbonate can circulate in the order of the washing tank 3, the crystallization means 4, the heating means 5, and the washing tank 3, and in particular, the ethylene carbonate liquefied by the heating means 5 The final step of the circulation for transferring the water to the washing tank 3 is included.

  This liquid ethylene carbonate flow can be produced, for example, by using a pump. Through this circulation process, the ethylene carbonate liquefied and regenerated by the heating means 5 is fed into the washing tank 3 and is again formed of the organic coating. It will be used for removal.

  In this organic film cleaning liquid crystallization regeneration method, the cleaning process, the circulation process, and the regeneration liquid storage process are preferably performed at a temperature at which the cleaning liquid does not solidify, and achieved by using a heater as a heat retaining means for maintaining this temperature. can do. The temperature at this time is preferably about 40 ° C.

  If the above-described operation is repeated, the concentration of the organic substance in the cleaning liquid in the cleaning liquid storage tank 411 increases. Therefore, the proportion of the organic substance mixed in when crystallization increases and the purification accuracy decreases. When this concentration is reached, the cleaning liquid needs to be transferred to the resist concentration tank 7.

(Second Embodiment)
Further, the second embodiment of the organic film cleaning liquid crystallization regeneration apparatus according to the present invention is different from the first embodiment except that the crystallization means and the heating means of the cleaning liquid crystallization regeneration apparatus 1 are different. Are the same. FIG. 5 is a diagram showing a more specific outline of the configuration of the crystallization means and the heating means used in the present embodiment.

  The crystallization means 42 in this embodiment includes a cooling tower 421 that cools the cleaning liquid transferred from the cleaning tank, a heating means 51 that covers the periphery of the cooling tower, and a cooling unit 422 that covers the heating means, Heat exchange can be performed indirectly through the wall, and the cooling tower 421 is configured so that the inside of the tower can be cooled by the cooling unit 422 and can be heated by the heating means 51 after the cooling is stopped. The crystallization means and the heating means are integrally formed.

  The cooling tower 421 is formed in an elongated cylindrical shape, and the cleaning liquid transferred from the cleaning tank is supplied from the top of the tower, and the cooled cleaning liquid can be discharged from the bottom. In the column, the inside of the tower is cooled so that ethylene carbonate crystals can adhere to the inner wall surface of the tower. In addition, since the inside of the tower can be heated after the crystals are attached, the purified ethylene carbonate liquid can be discharged from the bottom of the tower by melting the ethylene carbonate crystals attached to the inner wall surface of the tower. It has become.

  When performing the crystallization process and the heating process using the crystallization means 42, first, the cleaning liquid is transferred from the cleaning tank 3 into the cooling tower 421, and the cleaning liquid passes through the tower. At this time, the flow rate is adjusted so as to pass slowly through the tower so that a sufficient time is allowed for the cleaning liquid to be sufficiently cooled.

  For example, when the cooling tower 421 has a cylindrical shape with a circular horizontal cross section, the diameter of the cross section is 10 cm, the length is 50 cm, and the volume is 4 L. The time taken to pass is about 10 minutes, and the circulation rate of the cleaning liquid in the tower at that time is 1 cm / second at the linear velocity (LV), and the processing capacity of the cleaning liquid is 7.5 L / hour.

  Here, when the cleaning liquid is sufficiently cooled, ethylene carbonate crystals adhere to the inner wall of the cooling tower 421 and are deposited. The cleaning liquid that has passed through the cooling tower 421 is temporarily stored in the circulation tank 423. The circulation transfer pump 424 lifts the cooling tower 421 to the top of the cooling tower 421 at a predetermined linear velocity (LV) set from the circulation tank 423, and can pass through the cooling tower 421 again. As long as it does not come out, it is preferable to circulate through the cooling tower 421 many times. In order to make the liquid concentration in the cooling tower 421 uniform, liquid circulation is preferably performed by the circulation pump 425. At this time, a new cleaning liquid may be simultaneously supplied from the cleaning tank.

  When the ethylene carbonate crystals are sufficiently deposited on the inner wall of the cooling tower 421, the cleaning liquid is discharged from the tower to the circulation tank 423, and only the ethylene carbonate crystals adhering to the inner wall are left inside the cooling tower 421 to stop the cooling. . Next, when the inside of the tower is heated by the heating means 51, the crystals attached to the inner wall of the tower are melted to become a liquid, and the purified ethylene carbonate liquid is stored in the storage tank 426. This can be transferred to the washing tank by the circulation means 6.

[Organic coating cleaning apparatus and cleaning method]
Next, an organic coating film cleaning apparatus and cleaning method of the present invention will be described with reference to the drawings.

  FIG. 6 is a view showing an organic coating film cleaning apparatus of the present invention.

  The organic coating film cleaning device 71 is attached to the organic coating film cleaning liquid crystallization regeneration device 11, a pure water cleaning tank 72 for rinsing the cleaning liquid attached to the object to be cleaned from which the organic coating has been removed, and a pure water cleaning tank 72. It comprises a drying means 74 for drying the pure water, a washing basket elevator 73, and an ethylene carbonate exhaust port 75.

  In the case of such a configuration, the removal from the organic film to the drying can be continuously performed with one apparatus, and further, the organic film can be cleaned while regenerating and circulating the cleaning liquid. .

  The crystallization regenerator 61 used here has the regenerant liquid storage means 17 that can store the purified ethylene carbonate liquid after the heating means 5, but it takes time to cool the preceding stage. For this reason, once the purified ethylene carbonate is stored in the regenerating solution storage means 17 and the cleaning solution is circulated, it is preferable in terms of efficient circulation.

  In this case, the cleaning liquid used first is transferred to the crystallization means 4, and a new cleaning liquid is added to the cleaning tank, and the cooling of the first cleaning liquid is terminated while cleaning is performed with the newly added cleaning liquid. It is preferable. Therefore, in the present embodiment, it is preferable to perform cooling in a batch manner. In addition, the reproducing apparatus of the second embodiment can be applied as the crystallization reproducing apparatus.

  The pure water cleaning tank 72 contains pure water, and the object to be cleaned is immersed in the pure water cleaning tank 72 by immersing the cleaning object from which the organic film has been removed by the crystallization regenerating apparatus 61 of the organic film cleaning liquid. The cleaning liquid adhering to the object is washed away with pure water. Here, also in the pure water cleaning tank 72, a swinging means and an ultrasonic means can be used in the same manner as the organic coating cleaning tank 3 in order to efficiently rinse with pure water.

  The drying means 74 dries pure water by blowing air to the object to be cleaned that has been cleaned in the pure water cleaning tank 72, and applies it to the object to be cleaned by a method in which dry air is blown from the air blowing port toward the cleaning basket. The object to be cleaned can be dried by blowing off the adhering pure water and simultaneously evaporating and drying the pure water.

  The cleaning basket elevator 73 can lift and lower the cleaning basket containing the cleaning object up to the air outlet of the drying means 74 disposed at the top of the pure water cleaning tank 72 after the cleaning object is cleaned with pure water. It can be done. This may be raised and lowered in order to perform cleaning efficiently during pure water cleaning.

  The ethylene carbonate exhaust port 75 exhausts vapor of ethylene carbonate that diffuses into the apparatus, and gas is discharged from the exhaust duct to the external environment.

  In this process, if the cleaning basket is automatically moved from the crystallization regenerating apparatus 61 of the organic film cleaning liquid to the pure water cleaning tank 72 by using the conveying means, the cleaning is efficiently performed without bothering human hands. Work can be done.

  Further, it is preferable that the organic film cleaning liquid crystallization regenerating apparatus 61, the pure water cleaning tank 72, and the transport means for moving the cleaning basket have a heat retaining means. This is because, when ethylene carbonate is used as the cleaning liquid, it solidifies on average at a solidification temperature of ethylene carbonate of 36.4 ° C. or lower, so that a film of ethylene carbonate is formed on the object to be cleaned in the cleaning operation at room temperature. It is because it ends up. By using this heat retaining means, solidification of ethylene carbonate can be prevented and the object to be cleaned can be kept clean.

  Next, an organic film cleaning liquid crystallization regeneration method using this apparatus will be described.

  First, in the organic film removal step, the object to be cleaned is put in the cleaning basket 22, and the cleaning basket is immersed in the cleaning solution of the cleaning tank 3 of the crystallization regenerator so that the organic film is sufficiently dissolved and removed. The organic film of the object to be cleaned is removed by dipping. At this time, in order to efficiently remove the organic coating, it is preferable to swing the cleaning basket in the cleaning tank.

  The immersion time may be appropriately determined in consideration of the thickness and amount of the organic film to be removed, the solubility of the organic film in the cleaning solution, and the like. For example, if the film is about 1 mm thick of a novolak resist, 20 The organic coating can be completely removed by immersion for a minute.

  When the removal of the organic film is finished, the washing basket is lifted from the washing tank 3, then moved to the pure water washing tank 72, and then immersed in the pure water of the pure water washing tank 72 to remove the organic film. Rinse away the cleaning solution adhering to.

  At this time, the cleaning may be performed by swinging or ultrasonic vibration similarly to the cleaning in the crystallization regeneration device 61 of the organic coating film cleaning liquid, or may be performed by raising and lowering the cleaning basket using the cleaning basket elevator 73. .

  After the cleaning of the object to be cleaned with pure water is completed, the cleaning basket is then lifted from the pure water cleaning tank 72 by the cleaning basket elevator 73 and moved to the air outlet of the drying means 74 and held. Next, air is blown onto the object to be cleaned from the air outlet of the drying means, and the pure water adhering in the pure water cleaning tank 72 is evaporated and dried.

  The pure water is supplied to the pure water cleaning tank 72 from the pure water supply pipe 76 until the pure water cleaning tank 72 becomes full. The pure water used for rinsing the object to be cleaned is the rinse. Overflowing by the above operation, the water is drained through a pure water drain pipe 77 from a tank provided outside the pure water cleaning tank 72. Since the pure water used for this rinsing is not a little contaminated once it is used, all the water is drained through the pure water drain pipe 77 and emptied before the next rinsing. The pure water is filled again through the pure water supply pipe 76. At this time, in order to keep the pure water washing tank itself clean, it may be rinsed by supplying and draining pure water.

  In the present embodiment, it is preferable to use a heat retaining means such as a heater when removing the organic coating, cleaning with pure water, or transporting from the cleaning tank to the pure water cleaning tank. When the cleaning liquid is ethylene carbonate, it solidifies when the solidification temperature of ethylene carbonate becomes 36.4 ° C. or lower on average, so that the solid of ethylene carbonate adheres to the object to be cleaned by using the heating means. And the object to be cleaned can be kept clean. It is preferable that the heating temperature at this time is 40-80 degreeC.

  In the present embodiment, the regenerating liquid storage means 17 is provided after the heating means 5, and this is not only the liquid regenerated by the used cleaning liquid crystallization regenerating apparatus 61 but also the ethylene carbonate cleaning liquid stock solution and It is possible to prepare a cleaning liquid obtained by subjecting the cleaning liquid to ozone treatment, and this regenerating liquid storage means 17 is necessary to perform uniform cleaning.

  Hereinafter, the present invention will be described in detail based on examples.

(Example 1)
In this example, a cleaning liquid crystallization regenerating apparatus having the configuration shown in FIGS. 3 and 4 and having an external dimension of 600 mm in depth × 600 mm in width × 1000 mm in height arranged on a caster was used.

  The components constituting this apparatus are a cylindrical drum 412 (diameter: 170 mmφ × length: 300 mm) of SUS-316 material with a mirror finish, and a 25 mmφ cooling water introduction pipe 414 and a cooling water discharge pipe 415 are welded to the centers of both ends, respectively. A refrigerant body occupying the inner volume of the semi-cylindrical body is built in. The used cleaning liquid 2 (ethylene carbonate 80% + resist component 20% mass ratio) is stored in a semi-cylindrical cleaning liquid storage tank 411 (semi-cylindrical diameter 300 mmφ × length 350 mm) below the outer periphery of the drum. While the drum 412 was rotating slowly at 30 rph, the temperature was maintained with cold water inside the drum so that the drum surface was about 15 ° C., and ethylene carbonate crystals were deposited on the drum surface. The deposited crystals were scraped off with an elastomer scraping scraper 413 that was in contact with the outer periphery of the drum and kept at 50 ° C., and the liquefied ethylene carbonate was taken out into a storage tank kept at 50 ° C. %, And the recovery rate was 75%.

  The ethylene carbonate crystals scraped off by the scraper are not heated on the scraper, but are subjected to solid-liquid separation at a rotational speed of 3000 rpm by using a SUS304 material cylindrical type 300 mmφ and a rotary centrifuge with a filter cloth built-in rotor. When the obtained ethylene carbonate crystals were made into a solution at 40 ° C., the recovered regenerated solution had a purity of 98% and a recovery rate of 70%, and an extremely high purity ethylene carbonate solution could be obtained.

  In addition, when the cleaning liquid 2 was treated with ozone and the cleaning liquid in which the resist component was partially decomposed into an organic acid was subjected to crystallization regeneration processing by the same method, the same regeneration processing result was obtained.

(Example 2)
In this embodiment, a cleaning liquid crystallization regenerating apparatus having the configuration shown in FIG. 5 and having an external dimension of 600 mm in depth × 400 mm in width × 1000 mm in height arranged on a caster was used. The crystallizing means 42 of this apparatus is formed in a cylindrical shape, the inside is a cooling tower 421 (diameter 100 mm × length 500 mm), a heating unit 51 having a width of 10 mm on the outside, and a cooling unit 422 having a width of 10 mm on the outside. Each material is made of a cylindrical drum of SUS-316 material that is mirror-finished and sealed at both upper and lower ends. The circulation tank 423 is a cylindrical container with an internal mirror finish SUS-316 material and an internal volume of 10 L, and the circulation transfer pump 424 is a small magnet pump that can be supplied at 10 L / hour. The circulation pump is for homogenizing the liquid concentration in the cooling tower, and the same type as the circulation transfer pump was used. As in Example 1, the outer surface temperature of the cooling tower may be maintained at about 15 ° C., and the circulating liquid in the cooling tower may be maintained at a minimum temperature of 40 ° C. or more. In this example, the circulating temperature is about 55 ° C. The temperature was controlled in the tank 423. The amount of crystals deposited from the outer periphery of the cooling tower 421 is preliminarily experimented with the amount of precipitation per hour, the cleaning liquid supply amount, the circulation amount, and the precipitation time are calculated, the cooling / circulation is stopped, and the residual liquid is circulated first. The sample was extracted into a tank, the heating means 51 was operated, the crystals were dissolved at about 50 ° C., transferred to a SUS316 mirror-finished cylindrical transfer storage tank internal volume 20 L, and stored in the same manner as in Example 1. The purity was 90% and the recovery rate was 75%.

(Example 3)
In this embodiment, as shown in FIG. 6, the cleaning apparatus 71 and the cleaning liquid crystallization regenerating apparatus 1 are configured. Further, after the heating means 5 of the cleaning liquid crystallization regenerating apparatus 1, a purified ethylene carbonate liquid is stored. It is comprised with the apparatus which has the regeneration liquid storage means 17 which can be performed. The external dimensions of the cleaning device 71 are devices arranged on a caster with a depth of 1000 mm × width of 1640 mm × height of 1800 mm. Further, the cleaning tank 3 used here has a size of 450 mm × 450 mm × 420 mm and an internal volume of 80 L, and the swinging means 21 for cleaning has a cleaning basket 22 (320 mm × 320 mm × 320 mm size) into which an object to be cleaned is placed. The holding portion 23 that can be held and a cam connected to the holding portion are configured to swing the cleaning basket 22 by rotating the cam 24 (swing width 6 cm, vertical movement, 15 times / minute). Can be made. Further, the pure water cleaning tank 72 (450 mm × 450 mm × 420 mm size) has an internal volume of 80 L, and a swinging condition (swinging width 6 cm, vertical motion) is constituted by a cleaning basket elevator 73 similar to the swinging means 21. Yes.

  First, 60 L of an ethylene carbonate solution is poured into the cleaning tank, and the pure water cleaning tank is filled with pure water from the pure water supply pipe 76, and the spin coater cup (resist adhesion cup for 200 mmφ silicon wafer, A cleaning basket 22 (320 mm × 320 mm × 320 mm size) containing a resist film having a thickness of about 1 mm was immersed. The washing basket was washed for 20 minutes while being rocked by the rocking means.

  Immediately after the cleaning with the ethylene carbonate cleaning solution, it was immersed in a pure water cleaning tank in which pure water was full, and the cleaning basket was swung by the cleaning basket elevator 73 for 3 minutes. At this time, the pure water used for rinsing overflowing from the pure water washing tank is drained through the pure water drain pipe 77 from the bottom of the tank arranged outside the pure water.

  The washing basket that has been rinsed with pure water is lifted up to a predetermined position by a washing basket elevator, and the pure water adhering to the spin coater cup is blown off by the dry air blown from the drying means on the left and right, and at the same time pure water is discharged. Evaporated to dryness. This drying with dry air was carried out for 15 minutes and taken out, and the cleaning state was visually confirmed. As a result, it was confirmed that the resist film adhering to the spin coater cup was all removed and that the cleaning was sufficiently performed. The above operation was performed while maintaining the temperature in the organic film removing / cleaning apparatus at around 40 ° C.

  After this cleaning operation is completed, the pure water cleaning tank immediately drains the entire amount of cleaning water, and waits for fresh pure water to be filled at a flow rate of 160 L / min for 30 seconds.

  When the resist-adhered cleaning product is repeatedly cleaned in the cleaning tank, the colorless and transparent ethylene carbonate cleaning solution initially becomes a cleaning solution containing the resist that has been stripped and cleaned, and becomes transparent brown. Next, the resist-contaminated cleaning liquid is regenerated by the cleaning liquid crystallization regenerating apparatus 1 shown in the first embodiment, transferred to the regenerating liquid storing means 17, and added with an ethylene carbonate cleaning liquid stock solution to prepare the cleaning tank 3. To supply. If the number of washings is repeated, it will not be completely colorless and transparent, and the color tone of transparent brown will become dark and the dissolving ability of the organic coating will decrease. Therefore, the washing solution will be exchanged or formulated with an ethylene carbonate stock solution. The management of cleaning liquid replacement time and stock preparation preparation may be determined by measuring the cleaning operation status and the degree of color tone change to transparent brown with a chromaticity meter.

It is the conceptual diagram which showed 1st Embodiment in the crystallization reproduction | regeneration apparatus of the organic film washing | cleaning liquid which concerns on this invention. It is a conceptual diagram of the rocking | swiveling apparatus for rocking | fluctuating a cleaning target object. It is the figure which showed the crystallization means in 1st Embodiment. It is sectional drawing of the crystallization means shown in FIG. It is the figure which showed the crystallization means used for 2nd Embodiment in the crystallization reproduction | regeneration apparatus of the organic film washing | cleaning liquid which concerns on this invention. It is the figure which showed embodiment in the washing | cleaning apparatus of the organic film which concerns on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,11,61 ... Cleaning liquid crystallization reproduction | regeneration apparatus, 2 ... Cleaning liquid, 3 ... Cleaning tank, 4, 41, 42 ... Crystallizing means, 5, 51 ... Heating means, 6 ... Circulation means, 7 ... Resist concentration tank, 17 ... regenerating liquid storage means, 21 ... oscillating device, 22 ... cleaning basket, 23 ... holding means, 24 ... cam, 71 ... cleaning device for organic coating, 72 ... pure water cleaning tank, 76 ... pure water supply pipe, 77 ... Pure water drain pipe, 411 ... cleaning liquid storage tank, 412 ... drum, 413 ... scraper, 414 ... cooling water inlet, 415 ... cooling water outlet, 421 ... cooling tower, 422 ... cooling section, 423 ... circulation tank, 424 ... Circulation transfer pump, 425 ... circulation pump, 426 ... transfer reservoir

Claims (15)

A cleaning tank containing a cleaning liquid containing ethylene carbonate as an active ingredient;
Crystallization means for precipitating ethylene carbonate crystals by cooling the cleaning solution dissolving the organic coating transferred from the cleaning tank;
Heating means for heating the ethylene carbonate obtained by the crystallization means to a liquid state;
An apparatus for crystallizing and regenerating an organic coating film cleaning liquid, comprising: circulating means for transferring and circulating ethylene carbonate liquefied by the heating means from the cleaning tank via the crystallization means and the heating means to the cleaning tank.   2. The organic film cleaning liquid crystallization regeneration apparatus according to claim 1, wherein a plurality of combinations of the crystallization means and the heating means are provided.   The apparatus for crystallization regeneration of an organic coating film cleaning liquid according to claim 1 or 2, further comprising solid-liquid separation means for solid-liquid separation of the cleaning liquid attached to the ethylene carbonate crystals obtained by the crystallization means.   4. The apparatus for recrystallizing an organic coating film cleaning liquid according to any one of claims 1 to 3, further comprising a regenerating liquid storing means for storing ethylene carbonate that has been liquefied by the heating means.   5. The crystallization of the organic coating film cleaning liquid according to claim 1, wherein the cleaning tank, the circulation unit, and the regenerated liquid storage unit include a heat retaining unit that maintains a temperature at which the cleaning liquid does not solidify. Playback device. An apparatus for crystallizing and regenerating an organic coating film cleaning liquid according to any one of claims 1 to 5,
A pure water cleaning tank for rinsing the cleaning liquid after removing the organic film with the organic film cleaning liquid crystallization regeneration device;
A drying means for drying the adhering pure water after washing in the pure water washing tank;
An organic coating film cleaning apparatus comprising:   An organic coating film cleaning apparatus, comprising: a heat retaining unit that maintains a temperature at which the cleaning liquid does not solidify in the organic coating film cleaning apparatus. A cleaning process for dissolving and removing the organic film with a cleaning liquid containing ethylene carbonate as an active ingredient;
A crystallization step of precipitating ethylene carbonate crystals by cooling the cleaning solution in which the organic coating is dissolved by the cleaning step;
A heating step of heating the ethylene carbonate crystals precipitated in the crystallization step into a liquid state;
A method for recrystallizing an organic coating film cleaning solution, comprising: a circulating step for circulating the ethylene carbonate liquid obtained in the heating step through the crystallization step and the heating step to the cleaning step. .   8. The organic film cleaning liquid crystallization regeneration method according to claim 7, wherein the combination of the crystallization step and the heating step is performed a plurality of times.   10. The method for recrystallization of an organic coating film cleaning liquid according to claim 8 or 9, further comprising a solid-liquid separation process for solid-liquid separation of the cleaning liquid adhered to the ethylene carbonate crystals obtained in the crystallization process.   The method for recrystallization of an organic coating film cleaning liquid according to any one of claims 8 to 10, wherein in the crystallization step, the cleaning liquid is cooled with cooling water at 30 ° C from a temperature at which the cleaning liquid does not solidify.   The method for crystallizing and regenerating an organic coating film cleaning liquid according to any one of claims 8 to 11, further comprising a regenerating liquid storing step of storing ethylene carbonate that has become liquid by the heating step.   The method for crystallizing and regenerating an organic coating film cleaning liquid according to any one of claims 8 to 12, wherein the cleaning step, the circulation step, and the regeneration solution storage step are performed while maintaining a temperature at which the cleaning solution does not solidify. A pure water cleaning step of rinsing the cleaning liquid adhering to the object to be cleaned from which the organic coating has been removed by the cleaning step in the method for crystallizing and regenerating an organic coating film cleaning liquid according to any one of claims 8 to 13. When,
A drying step of evaporating and drying the water adhering in the pure water cleaning step;
A method for cleaning an organic coating, comprising:   The organic film cleaning method according to claim 14, wherein the cleaning step, the cleaning liquid circulation step, and the pure water cleaning step are performed while maintaining a temperature at which the cleaning liquid does not solidify.

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