KR20090025103A - Apparatus for photoresist stripper recycle - Google Patents

Abstract

An apparatus for photoresist stripper recycle is provided to prevent the environmental contamination even though the stripper solvent does not need to be supplemented. An apparatus for photoresist stripper recycle comprises the first evaporator in which the first distillation tower(D-1) removing the impurity of the feeding mechanism and photoresist stripper waste water of the photoresist stripper waste water is formed; the second evaporator including the second distillation tower(D-2) evaporating the stripper solvent composition from the stripper waste water and a condenser(4) connected to the second distillation tower; the third evaporator including the third distillation tower(D-3) tower which successively evaporates the stripper solvent composition and a condenser(10) connected to the third distillation.

Description

Apparatus for photoresist stripper recycle}

The present invention relates to an apparatus for regenerating a photoresist stripper waste liquid stripper solvent, and more particularly, to regenerate each of the stripper solvents contained in the photoresist stripper waste liquid generated in a liquid crystal display device or a semiconductor device manufacturing process at a high purity electronic level. Related to the device.

The stripper waste liquid generated during the manufacturing process of electronic components such as semiconductor wafers and liquid crystal display device glass substrates contains impurities such as moisture and heavy metals together with the photoresist resin in addition to the stripper solvent. Most of these stripper wastes are incinerated or low-level recycled as process fuels, which is undesirable because they cause secondary pollution and inefficient energy consumption, leading to environmental pollution and weakening corporate competitiveness in the IT industry. Moreover, due to the rapid development of IT technology, the 7th generation production line, which can manufacture not only commercial 40-47 inch LCD panels but also 82-inch products, is operating for LCD production with the largest amount of stripper waste liquid. As the development of the 9th generation production line is planned, the size of LCD substrates is growing rapidly and the types of substrates are diversified. Accordingly, the quantity of stripper solvent is also increasing proportionally. Given this reality, there is a greater need for recycling technology for stripper waste liquids that can produce high-purity recycled stripper solvents at low cost, which can replace the new electronic grade stripper solvents that are absolutely cost-saving beyond the simple regeneration of stripper waste liquids. It's a losing situation.

On the other hand, as a regeneration technology of the stripper waste liquid, Korean Patent No. 0306649 and Japanese Laid-Open Patent Publication No. 2005-288329 describe the regeneration of the stripper solvent by removing low-boiling substances such as water and high-boiling substances such as photoresist resin from the stripper waste liquid. have. However, the above prior arts are specified as a regeneration method of a sub-process concept attached to an electronic component manufacturing process such as a semiconductor wafer or a liquid crystal display device glass substrate, and thus purified into a high purity electronic regeneration solvent that can replace a stripper solvent for a new liquid. Is difficult. In addition, due to the nature of the sub-process regeneration method, the application range is not limited to the stripper waste liquid having a specific composition of some factories, but also a simple total stripper recycling method that recovers the stripper composition in the form of a mixture and supplements the insufficient components. Due to this, additional equipment and processes, such as a concentration correction mixing device, are accompanied, thereby increasing the regeneration cost and the complexity of the process system, which makes the regeneration operation difficult. In addition, the regeneration process, which is performed after the amount of generated stripper waste liquid reaches a certain level because it is collected and connected to sub-processes of a manufacturing process such as an LCD glass substrate, is not preferable in terms of energy efficiency. In addition, in the current trend in which the quantity of stripper organic solvent increases significantly due to the rapid increase in the size of the substrate for liquid crystal display devices, the operation of stripper waste liquid regeneration as a sub-process attached to the electronic component manufacturing process such as TFT-LCD glass substrate is performed. Both in terms of cost and cost. For this reason, there is a problem in realizing cost reduction and commercialization by stripper waste liquid regeneration. Therefore, there is a demand for the development of a regeneration apparatus and method capable of processing a large amount of stripper waste liquid generated from a manufacturing process of a liquid crystal display device or a semiconductor device without being limited to a specific composition, but with a high-quality regeneration solvent of an electronic grade. come. In addition, in order to secure a high separation efficiency by purification, the size of the existing rechargeable or multi-stage regeneration apparatus is uneconomical due to the large size of the regeneration method, and a regeneration method and a device that can improve the separation efficiency at a small scale should be developed.

Accordingly, an object of the present invention is to easily separate and purify the stripper composition solvent having a narrow boiling point, so that the waste liquid to be recycled is not limited to the photoresist stripper waste liquid of a specific composition, and an additional device for correcting the concentration of the recycled stripper solvent or The process is unnecessary and the separation and regeneration efficiency can be maximized without the large size of the regeneration device, and the high purity electronic stripper regeneration solvent that replaces the electronic grade stripper solvent for the new liquid from the photoresist stripper waste liquid is individually recovered. To provide a device.

Another object of the present invention is the stripper composition, which is difficult to separate the moisture that is mixed during the stripper waste solution due to the strong hygroscopicity of the stripper composition solvent. The present invention provides a recycling apparatus for waste liquid.

The photoresist stripper regeneration apparatus of the present invention comprises: a primary distillation apparatus having a supply device for the photoresist stripper waste liquid, and a primary distillation column for evaporating and removing low boiling point impurities from the photoresist stripper waste liquid transferred through the pipe from the supply apparatus; At the top of the second distillation column for condensing the stripper solvent composition evaporated at once, from the stripper waste liquid from the low boiling point impurities removed through the pipe connected to the bottom of the first distillation column, the condensed stripper solvent composition at the same time A secondary distillation apparatus having a connected condenser; A third distillation column for sequentially evaporating the stripper solvent composition transferred through the condenser of the second distillation unit according to the boiling point of the individual stripper solvent, and a condenser connected to an upper portion of the third distillation column for condensing the sequentially evaporated individual stripper solvent. It is characterized in that it comprises a; a third distillation apparatus having a.

In addition, the photoresist stripper regeneration apparatus of the present invention, in order to improve the recovery rate, the re-boiler connected to the bottom of the secondary distillation column, the concentration of the dissolved photoresist resin in the stripper waste liquid supplied to the re-boiler and the dissolving power to the resin Analytical apparatus for measuring the excellent content of NMP, characterized in that it comprises a condenser connected to the top of the distillation column to detect the analyzed content to supply the stripper waste liquid and industrial-grade NMP.

Referring to the present invention in more detail as follows.

The reproducing apparatus of the present invention may be operated as a sub-process in addition to the stripping process of the photo-etching process repeatedly performed in the manufacturing process of the semiconductor device or the liquid crystal display device, or after the manufacturing process of the semiconductor device or the liquid crystal display device. It is applicable to photoresist stripper waste liquors of various compositions withdrawn from the collection.

The photoresist stripper stock solution generally comprises individual stripper solvents such as an organic amine compound, a protic glycol ether compound and an aprotic polypolar compound, and the stripper waste solution generated after the stock solution is used in the stripping process is used as the stock solution. Along with the individual stripper solvents constituting the solvent, a photoresist resin and water dissolved therein, and a small amount of other organic solvents are included. The organic amine compound contained in the stripper stock solution or the stripper waste solution generally includes monoethanolamine (hereinafter referred to as "MEA") or monoisopropanolamine (hereinafter referred to as "MIPA"), and also a protic glycol ether compound. These generally include diethylene glycol monobutyl ether (hereinafter referred to as "BDG") or propylene glycol monomethyl ether acetate (hereinafter referred to as "PGMEA"), a thinner for cleaning substrates, and also aprotic polypolar compounds. Generally includes N-methyl pyrrolidone (hereinafter referred to as "NMP") or dimethylsulfoxide (hereinafter referred to as "DMSO"). It is common to include 1 to 30 parts by weight of the organic amine compound, 30 to 70 parts by weight of the protic glycol ether compound and 10 to 50 parts by weight of the aprotic multipolar compound based on 100 parts by weight of the stripper stock solution or the stripper waste solution. . The stripper stock solution or stripper waste solution of the present invention is, for example, MEA or MIPA alone or mixed together as an organic amine compound, BDG or PGMEA alone or mixed together as a protic glycol ether compound, or an aprotic multipolar compound. It is possible to have various compositions in which NMP or DMSO are singly or mixed together.

In the present invention, "low boiling point impurity" is an impurity having a lower boiling point than the individual stripper solvent contained in the photoresist stripper waste liquid, and preferably has a boiling point of 130 to 30 ° C, more preferably 120 to 50 ° C, most preferably Is an impurity of 110 to 70 ° C., and is usually a small amount of an organic solvent such as water for washing or IPA for waste.

In the present invention, "high boiling point impurity" is an impurity having a higher boiling point than the individual stripper solvent contained in the photoresist stripper waste liquid, and preferably an impurity having a boiling point of 235 DEG C or higher, typically forming a resist pattern in a gate process. It is a photoresist resin stripped after being used for, and contains a small amount of other impurities such as nonionic surfactants.

The term “high purity electronic stripper solvent” in the present invention refers to a new liquid solvent used for preparing a photoresist stripper stock solution having a purity of 99.5% or more of individual stripper solvents, 0.1% or less of water content, or a ppb level of heavy metal or total metal. The lower limit of the moisture content does not need to be specifically set, but is generally about 0.001%, and the total metal content is preferably 500 ppb or less and the lower limit is not particularly limited, but it is 1 ppb. It is enough.

“Industrial grade solvent” in the present invention is a solvent having a higher content of impurities such as heavy metals than the standard of electronic grade solvent, and having a lower purification level than the electronic grade solvent. Generally, the purity is 98.0% or more and the water content is 0.5% or less. , Heavy metal or total metal content of 1000 ppb or more, but depending on the application may be of lower purity or higher impurity content.

The photoresist stripper regeneration apparatus of the present invention is a primary distillation apparatus for removing low-boiling impurities, a secondary distillation apparatus for removing high-boiling impurities and at the same time recovering the stripper composition solvent in the form of a mixture, and an electronic grade individual stripper with fine water removal. And a tertiary distillation apparatus for regenerating the solvent, more specifically, the composition mixture of the composition having a narrow boiling point, which is difficult to separate from each other in high purity, into an electronic grade stripper individual solvent. However, the apparatus for increasing the regeneration yield is added to the secondary distillation apparatus for removing the high boiling point impurities, the primary distillation apparatus or the tertiary distillation apparatus may be added or deleted as necessary.

First, the primary distillation apparatus is a multi-stage distillation column or a packed distillation column to remove low-boiling impurities such as water from the photoresist stripper waste liquid or stripper waste liquid pretreated by a method such as neutralization, precipitation, and filtration.

In addition, the secondary distillation apparatus is a multi-stage distillation column or a packed distillation column to remove the high-boiling impurities such as photoresist resin from the stripper waste liquid from which the low-boiling impurities are removed through the primary distillation unit and to recover the stripper solvent composition in the form of a mixture. The process (total stripper recycling) is carried out.

In the third distillation apparatus, as a spiral spinning band distillation column, a high boiling point impurity is removed through the secondary distillation apparatus and additionally removes fine moisture from the stripper solvent composition to form a stripper solvent composition. Depending on the boiling point of each of the strippers, separate stripper recycling is performed in sequence with individual stripper regeneration solvents of high purity electronic level. The spinning band distillation column is a very fast and effective gas-liquid solution by maximizing the contact surface area between the volatilized vapor component and the condensed liquid component by rotating the spiral stirring column device made of metal or teflon material at a high speed inside the tower. Equilibrium is designed to achieve high resolution purification efficiency. By varying the rotational speed of the spiral stirring column apparatus in the spinning band distillation column can be properly adjusted the separation efficiency of the distillation column, the rotational speed of the stirring column apparatus is preferably 1500 ~ 2500rpm. Therefore, due to the high separation efficiency realized by the purification method, the stripping band distillation column removes fine moisture remaining in the stripper solvent composition such as NMP and BDG having high hygroscopicity to 0.1% or less, and each stripper having a narrow boiling point section. Easily separated and purified solvents can be individually separated and regenerated to an electronic grade quality with high purity.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram showing an embodiment of a regeneration apparatus of the present invention used for reproducing a photoresist stripper.

If necessary, the stripper waste liquid, which has not been subjected to the pretreatment process or has not been subjected to the pretreatment process, is sent to the raw material supply tank T-1 of the regeneration treatment process as shown in FIG. 1, and then operates the first transfer pump F-1. Transfer to the distillation column (D-1) of the primary distillation apparatus. Subsequently, the waste liquid transported into the first distillation column is heated above the boiling point of water to allow evaporation of low boiling point impurities such as moisture, and to prevent changes in the physicochemical properties of the stripper solvent contained in the stripper waste solution due to prolonged exposure to high temperatures. Distilled and extracted low boiling impurities such as water (boiling point 100 ℃) and IPA (boiling point 82 ℃) to the top of the distillation column while maintaining the temperature below 120 ° C, preferably 70 to 110 ° C. After recovery to (2), operate the second transfer pump (1-1) to transfer to a separate collection tank (T-2) and discard. Then, when the moisture content level of the stripper waste liquid from which the low boiling point impurities such as moisture are removed reaches 1 to 3% by weight (the range of the moisture content is a packed or multi-stage distillation column used as a primary distillation unit to the stripper waste liquid type). As a general removable range of the water contained, the water content may be in the range of 0.5 to 4% by weight depending on the type or condition of the primary distillation device), and these may be passed through a reboiler (3) The transfer pump (1-2) is operated to transfer to the distillation column (D-2) of the secondary distillation apparatus for stripper solvent composition recovery and photoresist resin removal. At this time, it is necessary to prevent the physical and chemical properties such as decomposition or deformation of the stripper solvent contained in the stripper waste liquid in the secondary distillation apparatus due to heat at a high temperature. Run it to reduce the pressure in the column and carry out the decompression operation. In the present invention, the pressure reduction distillation operation pressure is set to 80 torr, preferably 90 torr or more, so that the stripper solvent component can be recovered at a lower temperature, and the upper limit of the decompression operation sharply increases the temperature in the distillation column. In order to prevent thermal damage of the stripper solvent, it is preferable to set it to 110 torr or less because of the characteristics of the secondary distillation apparatus which distills by heating and collect | recovers the whole stripper solvent composition. However, if the reduced pressure distillation pressure is 80 torr or less, due to the entrainment of the metal components heavy metal content is difficult to control to ppb level. Subsequently, the stripper waste liquid transferred to the secondary distillation apparatus is rapidly heated to a temperature higher than the boiling point of the highest boiling component among the solvent components constituting the stripper to remove the high boiling impurities, thereby forming the stripper above the distillation column. The composition can be separated by distillation and extraction at once and sent to the condenser 4 to condense, and at the same time, high boiling point impurities such as photoresist resin dissolved in the stripper waste liquid are solidified and do not precipitate. And remain in the reboiler (7), these can be removed by operating the fourth transfer pump (2-1) to transfer to a separate collection tank (T-3) and then discarded. The stripper composition is then condensed in the condenser (4) and temporarily stored to distill all of the stripper solvent composition at once to remove the extremely small amount of water remaining due to the hygroscopicity of the stripper solvent component from the first regenerated stripper solvent composition. After the recovery to the tank (5) to operate the reflux pump (5-2) and the sixth transfer pump (2-3) is transferred to the distillation column (D-3) of the third distillation apparatus. The third distillation unit is a spinning band type distillation column, and the spiral stirring column device 9 made of metal or teflon material is rapidly rotated at a speed of up to 2,500 rpm, resulting in high separation efficiency by increasing the theoretical number of towers. Removal of fine impurities or high purity separation for narrow boiling points is achieved. A spiral stirred column device 9 in the distillation column was removed to remove the fine moisture remaining in the first distillation apparatus and remaining at a level of 1 to 3% by weight from the stripper solvent composition transferred to the third distillation apparatus. Rotate rapidly above rpm and reduce the distillation operation pressure to 90 torr or more, but distillation is carried out under the condition that the upper limit is set to 300 torr, and the moisture content after the removal and removal of the residual moisture absorbed in the stripper solvent composition 0.1% or less, generally 0.001 to 0.1%. The volatile components including the fine water to be removed are condensed in the condenser 10 and then recycled to the primary distillation apparatus and distilled, so that the water is discarded after being transferred to a separate collection tank (T-2) and included in the volatile component. Some stripper solvents are returned to the secondary distillation unit and recovered without loss.

Subsequently, the regeneration process of the stripper solvent from the stripper waste liquid which is advanced through the secondary distillation apparatus and the third distillation apparatus as described above will be described.

As shown in FIG. 1, the stripper waste liquid from which the low boiling point impurities have been removed is sent to the secondary distillation apparatus (D-2), and the distillation is carried out under the condition that the reduced pressure distillation operation pressure is 90 torr or more, and the upper limit is set to 110 torr. High boiling point impurities such as photoresist resin dissolved in the stripper waste liquid are concentrated to the bottom (6) and the reboiler (7) to a level that will not be precipitated and solidified to remove the high boiling point impurities and at the same time the stripper solvent composition The stripper waste liquid is rapidly heated to a temperature higher than the boiling point of the highest boiling point component of the stripper solvent constituting the stripper composition for distillation and extraction of the stripper composition at the same time. . The reflux ratio at this time is preferably set to 1-3. When the reflux ratio is less than 1, the fifth transfer pump 2-2, which is the reflux pump, is operated to the distillation tower D-3 of the third distillation apparatus through the sixth transfer pump 2-3, rather than the amount returned to the distillation column. As the amount of the stripper composition transferred and recovered becomes too large, an ideal equilibrium formed between the gas component and the liquid component composition in the column based on the distillation column material resin becomes unstable and smooth regeneration process operation becomes difficult. On the other hand, when the first regeneration process is operated with a reflux ratio of 3 or more, a high back pressure is generated in the tower due to the nature of the first regeneration process for regenerating the entire stripper solvent composition which rapidly heats and distills the temperature in the distillation column. ) May cause a phenomenon. Subsequently, the stripper solvent composition recovered at once is condensed in the condenser 4 and recovered to the temporary storage tank 5, and then the fifth transfer pump 2-2 under distillation conditions operated within the set reflux ratio range, which is a reflux pump. The sixth transfer pump (2-3) is operated to transfer to the distillation column (D-3) of the third distillation apparatus. Distillation temperature range of the primary regeneration process for recovering the stripper solvent composition at one time is preferably set to 81 ~ 158 ℃ including the examples as shown in Table 3.

Subsequently, the stripper solvent composition transferred to the spinning band-type third distillation apparatus is continuously heated above the boiling point of each stripper solvent constituting the stripper and continuously distilled to recover the individual stripper solvent. Each stripper solvent, which is volatilized and separated in the top of the boiling point, is condensed through the condenser 11 and then recovered to the temporary storage tank 12. The condenser 11 is provided separately from the fine moisture condenser 10 in consideration of the purity of the stripper solvent to be recovered. The stripper solvents recovered in the temporary storage tank 12 operate the seventh transfer pump 3-1 to provide high-quality electronic grade quality standards (purity: 99.5% or more, water content: 0.1% or less, total metal content: 500 ppb). The stripper solvent which satisfies the above specification is then individually recovered and recovered through the one micro filter 13, and each recovered stripper solvent is recovered separately. It is transferred to and stored in tanks T-4, T-5, T-6, T-7, and T-8. Referring to the embodiment, the regenerated stripper solvents are recovered to a high purity electronic level such that PGMEA is in the storage tank T-4, MIPA is in the T-5, MEA is in the T-6, and DMSO is in the T- At 7, NMP is individually transported and stored in the T-8. In addition, a solvent such as BDG (boiling point 230 ° C.), which is the highest boiling stripper solvent, is finally separated when all stripper solvents having a lower boiling point are distilled and separated, remaining in the tower or reboiler 14, and the stripper recovered As with the solvent, if it meets the high purity electronic grade quality standards, the eighth transfer pump 3-2 is operated to pass through the one micro filter 13 and then transferred to the corresponding storage tank T-9 and stored.

In the second regeneration process by the individual stripper solvent recovery method, as in the first regeneration process, it is necessary to prevent the stripper solvent components from being exposed to high temperatures to change physical and chemical properties such as thermal decomposition or deformation. The pressure reduction pump 15 connected to the distillation column is operated to lower the pressure in the column to perform a pressure reduction operation. In the present invention, the pressure reduction distillation operation pressure is set to 90 torr or more, so that the stripper solvent component can be recovered at a lower temperature, and the upper limit of the pressure reduction operation is related to the stripper solvent composition contained in the stripper waste liquid. To solve the problem that the separation of the electronic grade level becomes more difficult when the stripper solvent constituting the stripper solvent composition increases with the mixing of the stripper waste liquids of various compositions, and the width between the boiling points of the stripper solvents to be recovered becomes relatively narrow. For this purpose, it is preferable to set it to 150 to 300 torr, preferably 200 to 300 torr, more preferably 250 to 300 torr.

It is preferable that the reflux ratio of the tertiary distillation apparatus by the said individual stripper solvent recovery system is set to 3-17. If the reflux ratio is less than 3, the purity of the stripper solvent distilled to the distillation column (D3) does not reach the electronic level (more than 99.5%), and if the reflux ratio is 17 or more, the distillation rate becomes too slow. At the same time, it can cause overflow phenomenon due to the occurrence of high back pressure in the tower, making it difficult to operate a smooth and productive regeneration process. However, when the reduced pressure distillation operation of the tertiary distillation apparatus is performed at less than 150 torr, the reflux ratio is more preferably performed at 7 to 17, and when the reduced pressure distillation operation is performed at 150 to 300 torr, the reflux ratio is 3 to 12. More preferably.

In addition, the tertiary distillation apparatus uses a spinning band type distillation column (D-3), and the column-type stirred column apparatus 9 is rapidly rotated at a speed of up to 2,500 rpm while separating high purity for a mixture having a narrow boiling point width. In addition, the separation efficiency of the stirrer in the secondary regeneration process can be controlled as the number of stripper compositions contained in the stripper waste liquid increases. It is desirable to operate in the range of ~ 2,400 rpm. Operation exceeding 2,400 rpm is unfavorable in terms of safe operation because the load on the stirrer shaft becomes too large.

Distillation temperature range of the high-purity electronic grade stripper solvents recovered in each of the third distillation apparatus varies slightly depending on the embodiment as shown in Table 4, but the composition of the stripper solvent contained in the stripper waste liquid in which the present invention is implemented. In the limited case, the distillation temperature range of the high purity electronic stripper solvents is PGMEA in the stripper solvent under reduced pressure operation condition of 90 to 300 torr, reflux ratio condition of 3 to 17 and speed range of spinning band stirrer of 1,500 to 2,400 rpm. Is 75 ~ 115 ℃, MIPA is 91 ~ 128 ℃, MEA is 97 ~ 141 ℃, DMSO is 112 ~ 157 ℃, NMP is preferably set to 121 ~ 168 ℃, BDG is the residue of the regeneration process (Residue) As it is naturally recovered, it does not need to be specified for the distillation temperature range.

Meanwhile, in the operation of the conventional general regeneration apparatus, the general level of the reboiler 6 connected to the regeneration distillation tower (D-2) of the stripper waste liquid is 30 to 50 cm high at the top of the heat line tube (7a) of the reboiler (for example, For example, in order to suppress the occurrence of adverse effects on the regeneration process and apparatus due to the solidified photoresist in the general operation to maintain a level of 50% of the reboiling height, excessively increased beyond the level of the reboiler to operate excessively in the tower High back pressure occurs and causes a flooding phenomenon, and the separation efficiency decreases due to an increase in the amount of distillation in the tower, which is unnecessary due to an increase in the amount of reflux through the reflux tank (5). Reduced energy consumption and distillation efficiency may eventually lead to a decrease in the recovery rate of stripper waste liquor or insufficient concentration in the waste liquor in the reboiler. Photoresist resin, a large amount of waste solvent stripper also is contained in the transmission with the waste when the waste is transported to the impurity collection tank whereby it is difficult to expect a reproduction process of the high yields due to the increased loss of solvent stripper.

Therefore, the regeneration apparatus of the present invention may further include a regeneration recovery rate increasing device to increase the regeneration rate. Figure 2 is a schematic diagram showing an embodiment emphasizing the portion of the recovery recovery rate in the playback apparatus of the present invention.

In FIG. 2, distillation proceeds in a secondary distillation column so that the stripper composition solvent is recovered into the temporary storage tank 5 through the condenser 4 in the form of a mixture and into the reboiler 7 connected to the distillation column D-2. The concentration of the dissolved photoresist in the stripper waste liquid supplied is gradually concentrated to increase. Subsequently, a portion of the stripper waste liquid containing the dissolved photoresist having increased concentration is introduced into the gas chromatography 17 to analyze the NMP content in the waste liquid, and at the same time, another portion of the waste liquid is transferred to an ultraviolet absorbance meter 18. The concentration of the dissolved photoresist in the waste liquid is detected by flowing in and measuring the absorbance of the stripper waste liquid. At this time, in order to detect the concentration of the dissolved photoresist by the ultraviolet absorbance photometer 18, a correlation table between the concentration and the absorbance of the dissolved photoresist is prepared in advance by using the absorption characteristics of the dissolved photoresist in the stripper waste liquid. Should be used.

Subsequently, the concentration of the dissolved photoresist resin in the stripper waste liquid in the reboiler increases and the concentration of the dissolved photoresist detected by the ultraviolet light absorbometer 18 at the time point at which it starts to precipitate as a solidifying component results in dissolution photo in the stripper waste liquid. It can be referred to as the maximum saturation concentration of the resist, at which point the level of the stripper waste liquid in the reboiler can be determined as the first lowest level. Therefore, when the dissolved photoresist concentration detected by the ultraviolet absorbance photometer 18 does not exceed the maximum saturation concentration, the first controller 18a issues an output signal to open the first flow control valve 16-1. By opening and operating the transfer pump 2-4 to circulate to the top of the reboiler, a certain flow is made inside the reboiler, thereby delaying the time point at which the dissolved photoresist precipitates.

On the contrary, the concentration of the dissolved photoresist detected by the ultraviolet absorbance spectrometer 18 reaches the maximum saturation concentration, thereby increasing the flow rate of the stripper waste liquid supplied into the reboiler 7 to increase the concentration of the dissolved photoresist that is concentrated to the maximum. If it is to be reduced, the first controller 18a issues an output signal to open the second flow control valve 16-2 and operate the transfer pump 2-1 to partially discharge the waste liquid with the maximum concentration of dissolved photoresist. To a separate collection tank T-2, and at the same time, the first controller 18a generates another output signal to operate the transfer pump 1-2 to increase the flow rate of the stripper waste liquid supplied into the reboiler. By doing so, the level of the stripper waste liquid in the reboiler can be maintained above the first minimum level.

A portion of the stripper waste liquid (distillation residue) in the reboiler 7 is then introduced into the gas chromatography 17 to analyze the content of NMP relative to the total stripper solvent composition contained in the waste liquid. In addition, the second controller 17a is based on the NMP content analyzed from the gas chromatography 17, and the NMP content at the first low water level in the reboiling process for the stripper waste liquid type having an NMP content of 30% by weight. If it is less than the level, in order to lower the minimum level of the waste liquid, after calculating the deficiency of the NMP component, an output signal is issued to open the third flow control valve 16-3, and the transfer pump 2-5 is opened. It is operated and refilled from the industrial grade NMP supply tank 19 to the reboiler. When it is detected that the industrial grade NMP is supplied from the load cell 20 by the shortage, the second controller 17a issues an output signal to close the flow control valve 16-3 and stop the operation of the transfer pump 2-5. To shut off the supply and replenishment of industrial grade NMP.

Subsequently, by supplying and supplementing the industrial grade NMP to the reboiler 7 to make it suitable for the NMP content, the concentration of the dissolved photoresist resin in the stripper waste liquid further proceeds to precipitate as a solidifying component. The dissolved photoresist concentration detected by the ultraviolet absorbance spectrometer 18 at the point of time may be referred to as the maximum saturation concentration of the dissolved photoresist in the stripper waste liquid supplemented with the industrial grade NMP, and at this point, the stripper in the reboiler The level of the waste liquid can be determined as the second lowest level.

Subsequently, the level of the stripper waste liquid in the reboiler can be maintained above the second minimum level by controlling in the same manner as the method for improving the primary recovery recovery rate, and thereby the solidification component due to concentration and precipitation of the dissolved photoresist resin can be maintained. Further suppression of production can enhance the secondary recovery rate.

As described above, the photoresist stripper regeneration apparatus according to the present invention improves inefficient energy utilization aspects such as the limitation of the waste to be regenerated from the regeneration process subordinate to the stripping process and the discontinuous process operation. Of course, a number of cumbersome processes such as replenishment of stripper solvents are unnecessary, and high purity electronic stripper solvents individually recycled with high yields improved by the regeneration apparatus according to the present invention can be used in all electronic component manufacturing plants. As it can be applied to the stripping process, it not only contributes to the cost reduction of the IT industry, but also enables substantial stripper recycling, which is expected to greatly improve the environment.

Hereinafter, the present invention will be described in detail with reference to Examples, but the scope of the present invention is not limited by Examples.

The regeneration method and the regeneration yield enhancement method of the present invention were applied to the photoresist stripper waste liquids of various compositions generated in the semiconductor manufacturing process, and the composition of the stripper waste liquids used is shown in Table 1.

Stripper solvent content (% by weight) Impurity component content (% by weight) PGMEA MIPA MEA DMSO NMP BDG Photoresist resin moisture Etc  Example 1 - - - - 30 55 2.8 10 2.2  Example 2 - - 8.1 - 20 60 2.4 8.2 1.3  Example 3 7 12.5 4.3 14 17 30 3.1 10.2 1.9  Example 4 - - 15 - 10 62 1.9 9.3 1.8  Example 5 - - 10.3 - - 78 2.0 7.9 1.8

While performing the integrated regeneration treatment process according to the present invention from the stripper waste liquid of Examples 1 to 5, the distillation conditions of the low boiling impurity removal process made through the first distillation apparatus and the changed water content after the impurity removal process 2 is shown.

Example 1 Examples 2, 4, 5 Example 3 Vacuum Pressure (torr) 760 760 760 Distillation Temp. (℃) 72 to 98 71-98 74 to 102 Reflux Ratio 2 3 5 Water content after removal of low boiling impurities 3.3 1.6 to 2.0 2.3

Table 3 shows the distillation conditions of the primary regeneration process by recovering the stripper solvent composition made through the secondary distillation apparatus at once while performing the integrated regeneration treatment process according to the present invention from the stripper waste liquid of Examples 1 to 5. Indicated.

Example 1 Examples 2, 4, 5 Example 3 Vacuum Pressure (torr) 97 97 97 Distillation Temp. (℃) 132.7-158.0 103.1 ～ 157.8 82.5 ～ 157.7 Reflux Ratio 2 2 2

In addition, Table 4 shows the distillation conditions of the secondary regeneration process by the individual stripper solvent recovery method made through the third distillation apparatus.

Example 1 Example 2, 4 Example 3 Example 5 NMP MEA NMP PGMEA MIPA MEA DMSO NMP MEA Distillation Temp. (℃) 97 torr 125-142 98-111 120-139 79-85 93-97 99-107 114 -123 126-140 102-107 250torr 157-169 125-140 153-167 105-112 118-125 128-135 142 -153 154-167 129-135 Reflux Ratio 97 torr 10 10 10 15 15 12 10 10 7 250torr 5 10 5 15 12 10 7 5 5 Rotation Speed of Column (rpm) 97 torr 1,700-1,800 1,800-1,900 2,000-2,100 1,700-1,800 250torr 2,000-2,100 2,100-2,200 2,200-2,300 2,000-2,100

Subsequently, the content analysis results of the individual regeneration solvents of the high purity electronic grade finally recovered by performing the integrated regeneration treatment process according to the present invention under the distillation conditions of Tables 2, 3 and 4 with respect to the examples of Table 1 above Is shown in Table 5.

Purity (%) Water content (%) Total metal content (ppb) 97 torr 250 torr 97 torr 250 torr 97 torr 250 torr SPCE. 99.5 or more 0.1 or less 500 or less Example 1 NMP 99.63 99.67 ≤ 0.1 ≤ 0.07 ≤ 500 BDG 99.67 99.73 Examples 2 and 4 MEA 99.58 ≤ 99.59 ≤ ≤ 0.1 ≤ 0.07 ≤ 500 NMP 99.53 ≤ 99.55 ≤ BDG 99.62 ≤ 99.68 ≤ Example 3 PGMEA 99.51 99.52 ≤ 0.1 ≤ 0.07 ≤ 500 MIPA 99.48 99.51 MEA 99.45 99.52 DMSO 99.48 99.52 NMP 99.51 99.54 BDG 99.65 99.71 Example 5 MEA 99.62 99.63 ≤ 0.1 ≤ 0.07 ≤ 500 BDG 99.70 99.75 ≤ 0.1 ≤ 0.07 ≤ 500

Table 6 shows the results of the primary recovery recovery in accordance with the present invention from the stripper waste liquids of Examples 1 to 2 and 4 to 5.

First low water level ratio (% of normal water level) NMP content (wt,%) compared to the entire stripper composition in the first lowest level concentrated waste liquid Photoresist content (wt,%) in the 1st minimum level concentrated waste liquid Concentration ratio in the concentrated waste solution based on the first lowest level (photoresist / NMP) Recovery rate (%) Example One 12.9 10.9 25.0 2.3 85 2 18.6 7.8 14.8 1.9 79 4 25.3 5.2 9.0 1.7 72 5 37.1 0 7.3 - 65

Table 7 shows the results of further improving the recovery rate by supplementing NMP in Examples 2 and 4 to 5 of Table 6.

Industrial grade NMP replacement Concentration ratio in the concentrated waste liquid based on the 2nd lowest water level (photoresist / NMP) Final recovery rate Example 2 supplement 2.3 83 4 supplement 2.3 81 5 supplement 2.3 79

1 is a schematic diagram showing an embodiment of a regeneration apparatus of the present invention used for reproducing a photoresist stripper.

2 is a schematic diagram showing an embodiment of the regeneration apparatus of the present invention for increasing the regeneration yield in photoresist stripper regeneration.

Brief description of the symbols in the drawings

T-1: Raw Material Supply Tank

T-2, T-3: Impurity Collection Tank

T-4, T-5, T-6, T-7, T-8, T-9: stripper solvent storage tank

F-1, 1-1, 1-2, 2-1, 2-2, 2-3, 2-4, 2-5, 3-1, 3-2: transfer pump

D-1, D-2, D-3: Distillation column

1, 4, 10, 11: condenser

2, 5, 12: temporary storage tank

3, 7, 14: re-kill

7a: Reheating Fruit Line Tube

6: bottom of the tower

8, 15: decompression pump

9: spiral stirring column

13: micro filter

16-1, 16-2, 16-3: flow control valve

17: gas chromatography

18 UV absorbance meter

17a, 18a: controller

19: N-methyl pyrrolidone supply tank

20: load cell

Claims (8)

A primary distillation apparatus having a supply device for the photoresist stripper waste liquid, and a primary distillation column for evaporating and removing low boiling point impurities from the photoresist stripper waste liquid transferred from the supply apparatus through a pipe; A second distillation column for evaporating the stripper solvent composition at a time from the stripper waste liquid from which the low boiling point impurities are removed through the pipe connected to the bottom of the first distillation column, and at the top of the second distillation column for condensing the stripper solvent composition evaporated at once. A secondary distillation unit having a connected condenser; And A third distillation column for sequentially evaporating the stripper solvent composition transferred through the condenser of the second distillation unit according to the boiling point of the individual stripper solvent, and connected to an upper portion of the third distillation column for condensing the sequentially evaporated individual stripper solvent. A third distillation apparatus having a condenser; Reproducing apparatus of the photoresist stripper comprising a. The method of claim 1, And a condenser connected to an upper portion of the primary distillation column for condensing the low boiling point impurities evaporated from the primary distillation column. The method of claim 1, And a pipe connected to the bottom of the second distillation column for discharging high-boiling impurities not evaporated from the second distillation column. The method of claim 1, And a fine moisture condenser connected to an upper portion of the third distillation column for condensing the fine water remaining in the stripper solvent composition evaporated from the third distillation column. The method of claim 1, The first distillation column and the second distillation column is any one of a multi-stage distillation column and a packed distillation column regeneration apparatus of a photoresist stripper, characterized in that. The method of claim 1, A reboiler connected to the bottom of the second distillation column is further provided, wherein the high boiling point impurities are concentrated in the reboiler so as not to be precipitated and then discharged. The method of claim 6, And a supply device of N-methyl pipolydone connected to the reboiler, which is maintained at a concentration such that the high boiling point impurities in the reboiler are not precipitated. The method of claim 1, The third distillation column is a spiral spinning band type distillation column, characterized in that the regeneration device of the photoresist stripper.

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