KR101078871B1 - Recovery method of organic solvent from photoresist waste - Google Patents

Abstract

The present invention relates to a method for recovering a resist stripping waste liquid, and in particular, a method for recovering an organic solvent from a waste liquid generated after removing a photoresist in the manufacture of a semiconductor or a liquid crystal display, wherein the waste liquid is subjected to 40 to 200 ° C. under a pressure of 150 mmHg or less. A first distillation step of removing the resist by heating with a second distillation step of removing the water by fractional distillation of the liquid phase from which the resist is removed at 60 to 200 ° C. under a pressure of 100 mmHg or less; A method for recovering an organic solvent from a photoresist stripping waste liquid for recovering a mixed organic solvent containing an organic amine compound and a polar aprotic solvent.

According to the present invention, it is possible to prevent thermal decomposition of the water-soluble organic amine compound and the polar aprotic solvent from the waste liquid generated during the manufacture of a semiconductor or a liquid crystal display, and to obtain an excellent effect on the recovery of the organic solvent including the high purity thereof.

Waste solution, organic solvent, water-soluble organic amine compound, polar aprotic solvent, thermal decomposition prevention, recovery, distillation

Description

Recovery method of organic solvent from photoresist waste liquid {RECOVERY METHOD OF ORGANIC SOLVENT FROM PHOTORESIST WASTE}

The present invention relates to a method of recovering an organic solvent from a photoresist waste liquid. More particularly, the present invention relates to a display manufacturing process by removing various impurities contained in a photoresist waste liquid generated in a liquid crystal display device manufacturing process such as a semiconductor and a TFT-LCD. The present invention relates to a method for recovering an organic solvent that can be reused.

In addition, the present invention can be applied to the stripper composition for photoresists described in Korean Unexamined Patent Publication No. 2007-0114037 and Korean Unexamined Patent Publication No. 2007-0073617.

Lithography is used to manufacture electronic circuits, pixels, and the like in display device manufacturing processes such as semiconductors and TFT-LCDs. Lithography is a method used to generate fine patterns on a substrate. It is a process of transferring the circuit pattern of a mask to a board | substrate by irradiating light through the mask in which the desired pattern is printed on the board | substrate to which the resist is apply | coated.

The basic process of such lithography is as follows.

In order to selectively etch the metal film used in the wiring forming process of a semiconductor or a display device (TFT-LCD, PDP, OLED, etc.), a photo-lithography process is performed.

In particular, when the photolithography process is generally subdivided in a display device, a glass having a metal film which has been cleaned is strongly vacuumed at a lower portion of the glass so that there is no detachment of the glass in a spin coating machine. In general, the rotational speed is rotated at 2500 ~ 4500 rpm, the larger the size of the glass, the stronger the centrifugal force and if the breakaway occurs in the center of the glass may cause glass breakage and equipment damage.

When a certain amount of photoresist is dropped on the glass to which rotational force is applied, the liquid flows outward from the center by centrifugal force and the coating is coated on the metal film to a certain thickness.

Apply a photoresist uniformly on the substrate and soft-baking it to remove photoresist solvent to make a uniform and dry photoresist film, and then pass a mask of engraved light of a specific wavelength through the mask engraved on the substrate. When irradiated to the photoresist film, the photoresist film is divided into the lighted and unreceived portions according to the circuit pattern of the mask. At this time, the lighted portion causes chemical deformation by photosensitive action of the photoresist. By having different properties from those that are not, the pattern is formed in the developing process.

After the pattern forming process, the metal wiring is formed through an etching process, and then a process of removing the photoresist film by using a stripper can be used to implement the completed metal wiring. The stripper used to remove the photoresist film will contain trace metals, moisture, and resist components that are different from the initial chemical components.

Conventionally, the waste solution contaminated with impurities cannot be recycled and used, but a method of incineration and disposal has been used. However, in order to improve process efficiency and reduce costs, the waste solution containing impurities is recycled to remove the photoresist. There is a demand for the development of reusable technologies.

In order to recover the desired organic solvent from the waste liquid, the photoresist component needs to be separated and removed. Here, the photoresist is composed of a polymer material and other additives, and these are solid substances dissolved or dispersed in the organic solvent. Therefore, in order to recover the organic solvent from the waste liquid containing impurities, a technique for separating the solid photoresist and the liquid organic solvent is required.

In particular, when recovering the organic solvent, not only the photoresist component but also the metal ion component must be removed from the organic solvent. This is because the metal ion component included in the organic solvent may cause a problem such as an electrical short circuit by contaminating a fine circuit board when the organic solvent is reused in a semiconductor and display device manufacturing process.

Moreover, general industrial organic solvents contain very fine particles therein. These fine particles, when used in the electronics industry, can cause large defects due to the fine particles in organic solvents remaining in the electronic circuits. Management is needed. These microparticles are presumed to be mainly in the form of inorganic substances or in the form of organic substances which are insoluble in the organic solvent, but should be removed at a very low level regardless of their kind.

Therefore, research on the development of a process for recovering high-purity organic solvents to effectively remove water, photoresist, metal ions and fine particles contained in the waste liquid and re-introduce the process is necessary.

The present invention provides a method for effectively removing photoresist, metal ions, and fine particles from a waste solution generated in a semiconductor or liquid crystal display manufacturing process and recovering a mixed organic solvent containing a water-soluble organic amine compound and a polar aprotic solvent in high purity. I would like to.

The present invention is a method for recovering the organic solvent from the waste liquid generated after removing the photoresist in the manufacture of a semiconductor or liquid crystal display, the first distillation to remove the resist by heating the waste liquid to 40 to 200 ℃ under a pressure of 150 mmHg or less And a second distillation step of fractionally distilling the liquid phase from which the resist is removed at 60 to 200 ° C. under a pressure of 100 mmHg or less, and including a water-soluble organic amine compound and a polar aprotic solvent from the waste liquid. Provided are a method for recovering an organic solvent from a photoresist waste liquid for recovering a mixed organic solvent.

Hereinafter, the present invention will be described in more detail.

The present invention is to recover a mixed organic solvent containing a water-soluble organic amine compound and a polar aprotic solvent in a high purity without thermal decomposition from the waste of stripper used to remove the photoresist in the manufacture of semiconductor or liquid crystal display At the same time, it is characterized in that it is possible to effectively remove other impurities contained in the peeling waste liquid, that is, photoresist, metal ions and fine particles.

In particular, the present invention provides a method for recovering a mixed organic solvent containing a water-soluble organic amine compound which is highly decomposable at high temperature with a high boiling point polar aprotic solvent in a stripping waste solution and preventing the formation of byproducts. The present invention can be particularly effectively applied to photoresist waste liquids using stripper compositions for photoresists described in Korean Unexamined Patent Publication No. 2007-0114037 and Korean Unexamined Patent Publication No. 2007-0073617.

In the waste organic solvent stripping solution according to the present invention, the content of the water-soluble organic amine compound is 1 to 10% by weight, the content of the polar aprotic solvent is 20 to 95% by weight and the content of the corrosion inhibitor is 0 to 5% by weight. Solid content of 5 to 15% by weight and water content of 0 to 50% by weight can be used.

In the present invention, the water-soluble organic amine compound is monoethanol amine (MEA), 1-aminoisopropanol (AIP), 2-amino-1-propanol, N-methylaminoethanol (N-MAE), 3-amino-1-propanol, 4-amino-1-butanol, 2- (2-aminoethoxy) -1-ethanol (AEE), 2- (2-aminoethylamino) -1-ethanol, diethanol amine (DEA), triethanol amine (TEA ), And hydroxyethylpiperazine (HEP).

The polar aprotic solvent is N-methylpyrrolidone (NMP), 1,3-dimethyl-2-imidazolidinone (DMI), dimethylsulfoxide (DMSO), dimethylacetamide (DMAc), dimethylformamide ( DMF), N-methylformamide (NMF), and tetramethylenesulfone.

The corrosion inhibitor may be at least one selected from the group consisting of compounds represented by Formula 1, Formula 2, and Formula 3,

[Formula 1]

[Formula 2]

(3)

Wherein,

R ¹ , R ² are the same as or different from each other, and each independently hydrogen or a hydroxyl group,

R ³ is hydrogen, t-butyl group, carboxyl group (-COOH), methyl ester group (-COOCH ₃ ), ethyl ester group (-COOC ₂ H ₅ ) or propyl ester group (-COOC ₃ H ₇ ),

R ⁴ is hydrogen or an alkyl group having 1 to 4 carbon atoms,

R ⁵ and R ⁶ are the same as or different from each other, and each independently a hydroxyalkyl group having 1 to 4 carbon atoms.

Hereinafter, with reference to the accompanying drawings, it will be described in detail the organic solvent recovery process of the present invention to be easily carried out by those of ordinary skill in the art.

As shown in FIG. 1, the process of recovering the organic solvent from the waste liquid of the present invention is performed by supplying the distillation column through the storage tank 100 storing the waste liquid and distilling the distillation column 103.

In more detail, the distillation process of the present invention may be supplied to the heating tank 102 by using a pump in a storage tank 100 tank as a first distillation apparatus. In addition, the transfer pump 101 can be used as a pump for supplying raw materials to the heating tank 102. The waste liquid is supplied to the distillation column 103 from the heating tank 102. In addition, a condenser 104 for condensing the recovered organic solvent gas and a heating tank 105 and a condenser 106 may be used as the second distillation apparatus to selectively separate water or other impurities. Through this process, the mixed solution containing the water-soluble organic amine compound and the polar aprotic solvent is stored in the storage tank 107.

The present invention also relates to a photoresist waste liquid comprising a first distillation apparatus for removing resist from the stripping waste liquid and a second distillation apparatus for fractionating and distilling the liquid phase from which the resist is removed from the first distillation apparatus to remove water and impurities. An apparatus for recovering an organic solvent is provided.

In the apparatus for recovering the organic solvent according to the present invention, the first distillation apparatus is configured to increase the pressure in the distillation apparatus to reduce the evaporation temperature of the organic solvent evaporated in the heating apparatus and the distillation apparatus for removing the resist from the stripping waste liquid. A pressure reducing pump for lowering and supplying the mixed organic solvent in which the resist is removed to the second distillation apparatus.

The second distillation apparatus is a distillation apparatus for selectively removing water or other impurities from the stripping waste liquid, a pressure reducing pump for lowering the pressure in the distillation apparatus to lower the evaporation temperature of the organic solvent evaporated, and the evaporation in the separator. A condenser for condensing water and organic solvents and a reflux device for returning to the separator when the concentration of the organic solvent in the water vapor from the condenser is greater than the reference concentration, the organic material of the water and the water-soluble organic amine compound and the polar aprotic solvent Solvent is separated and discharged.

The organic solvent recovered from the second distillation apparatus has a content of a water-soluble organic amine compound of 2.5% by weight or less, a content of a polar aprotic solvent of 97.4-99.9% by weight and a content of water of 0.1% by weight or less. Do.

In the present invention, the first distillation process may be performed under a pressure of 150 mmHg or less, preferably 120 mmHg or less, more preferably 100 mmHg or less, and more preferably 85 mmHg or less. The first distillation process is carried out under a pressure of 150 mmHg or less in terms of preventing thermal decomposition of water-soluble organic amine compounds and polar aprotic solvents in the organic solvent to be recovered, and 85 mmHg or less in terms of overall process cost and efficiency of recovery performance. Preference is given to performing under pressure.

In addition, the first distillation process is carried out at a temperature condition of 40 ℃ or more, the first distillation process is 40 to 200 ℃, preferably 60 to 200 ℃, more preferably 80 to 180 ℃, more preferably 100 It may be carried out under a temperature condition of to 160 ℃. The first distillation process is performed at 40 ° C. or higher in terms of recovery performance for separating the resist component and the liquid organic solvent component including water from the waste liquid. The phenomenon can be prevented.

In the present invention, the second distillation process may be performed under a pressure of 100 mmHg or less, preferably 0.1 to 50 mmHg, more preferably 10 to 30 mmHg, and more preferably 10 to 20 mmHg. . The second distillation process is preferably performed under a pressure of 100 mmHg or less in terms of preventing pyrolysis of the organic solvent to be recovered, and is preferably performed under a pressure of 10 to 20 mmHg in terms of overall process cost and efficiency of recovery performance.

In addition, the second distillation process is carried out at a temperature condition of 60 ℃ or more, the second distillation process is 60 to 200 ℃, preferably 80 to 180 ℃, more preferably 100 to 170 ℃, more preferably 140 To 165 ° C. The second distillation process is performed at 60 ° C. or higher in order to remove other impurities including moisture from the liquid organic solvent mixture solution from which the resist is removed, and to prevent thermal decomposition of the water-soluble organic amine compound and the polar aprotic solvent in the organic solvent. It is preferable to carry out the distillation process at 200 ° C or less from the viewpoint of enabling it.

In the case of an organic solvent used in the electronic industry such as a semiconductor and a liquid crystal display, when an organic solvent containing a large amount of fine particles is used, product defects are caused and product productivity is greatly reduced. In order to remove such fine particles, the filtration process may be performed using a filter having a pore size of 1.0 micron, preferably 0.2 to 0.5 micron, and more preferably 0.1 micron or less, for the mixed organic solvent that has been subjected to the fractional distillation process. To remove the fine particles.

As described above, the present invention proposes a method for efficiently removing the fine particles contained in the waste liquid used for removing the photoresist and recovering a high purity mixed organic solvent, thereby effectively recovering the organic solvent recovered in accordance with the present invention. It can be used.

In particular, the present invention, the organic solvent recovered after the second distillation step, the content of the water-soluble organic amine compound and the polar aprotic solvent is 95 parts by weight or more, preferably 99 parts by weight or more, more preferably 100 parts by weight of the organic solvent. Preferably it is at least 99.5, that is, about 99.5 to 99.9 parts by weight to include a high purity tablet.

In addition, the recovered organic solvent may include a residual content of photoresist solids in an amount of 0 to 0.01 parts by weight based on 100 parts by weight of the organic solvent.

The organic solvent recovered after the second distillation step may have a residual content of the metal component in the range of 0 to 100 ppb for each metal component.

In the present invention, matters other than those described above can be added or subtracted as required, and therefore, the present invention is not particularly limited thereto.

The present invention, in the waste liquid containing the water-soluble organic amine compound and the polar aprotic solvent produced in the semiconductor or liquid crystal display manufacturing process as a main component, so that no side reaction product is generated, only the water-soluble organic amine compound and the polar aprotic solvent raw material component It is possible to recover the mixed organic solvent of high purity more efficiently by removing the photoresist, metal ions, fine particles, water and the like contained in the waste liquid more effectively while maintaining the composition.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited to the following examples.

In order to examine the foreign matter removal efficiency and high purity purification performance of the organic solvent recovery process according to the present invention, the waste liquid used for removing the photoresist in the display manufacturing process was tested. Here, the components contained in the waste liquid are as shown in Table 1 below, and the unit is parts by weight based on the total amount of the waste liquid.

division Composition ratio moisture 3.0 Organic solvent Polar aprotic solvent A 32.1 Water Soluble Organic Amine 2.3 Polar aprotic solvent B 13.6 Polar aprotic solvent C 39.8 Photoresist content 9.2 Photoresist Type Posi-pr

Example  One

The composition of the residue after performing the first distillation process at 200 ° C. under a pressure of 100 mmHg through the first distillation apparatus 103 as shown in FIG. 1 is shown in Table 2 below. , Unit is parts by weight.

division Composition ratio moisture 0.5 or less Organic solvent Polar aprotic solvent A 0.1 or less Water Soluble Organic Amine 2.9 Polar aprotic solvent B 6.9 Polar aprotic solvent C 1.3 Photoresist content 77.2

Example  2

After performing the second distillation process at 160 ° C. under the pressure of 20 mmHg through the second distillation apparatus 105 as shown in FIG. 1, the organic solvent of Table 1 is shown in Table 3 below. The unit is parts by weight.

division Composition ratio moisture 0.1 or less Organic solvent Polar aprotic solvent A 37.1 Water Soluble Organic Amine 0.3 Polar aprotic solvent B 14.8 Polar aprotic solvent C 45.9 Photoresist content -

Example  3

After performing the first distillation process as described in Example 1, the condensate discharged through the upper portion of the first distillation apparatus is shown in Table 4 below, and the unit is parts by weight.

division Composition ratio moisture 95.1 Organic solvent Polar aprotic solvent A 0.5 or less Water Soluble Organic Amine 0.5 or less Polar aprotic solvent B 0.5 or less Polar aprotic solvent C 3.43 Photoresist content -

Example  4

The organic solvent in Table 4 was discharged through a circulating distillation to remove water or other impurities by performing a second distillation process at 160 ° C. under a pressure of 20 mmHg through the second distillation apparatus 105 shown in FIG. 1. The organic solvent is shown in Table 5 below, and the unit is parts by weight.

division Composition ratio moisture 0.1 or less Organic solvent Polar aprotic solvent A 37.3 Water Soluble Organic Amine 0.1 Polar aprotic solvent B 16.7 Polar aprotic solvent C 45.9 Photoresist content -

Example  5

For the organic solvent finally recovered in Example 4, the concentration of the metal component contained was measured using a Perkin Elmer's Inductively Coupled Plasma Mass Spectrometer (ICP-MS DRC II), and the measurement results were as follows. Table 6 shows.

Analysis item Waste concentration
(ppb) Concentration after the second distillation
(ppb) Na 10.8 0.05 Mg 4.9 0.04 Al 86.7 0.04 K 5.4 0.3 Ca 25.1 0.1 Cr 4.3 0.01 Mn 0.33 0.1 Fe 11.7 0.2 Ni 1.4 0.1 Cu 454.6 0.1 Zn 25.9 0.2 Pb 10.4 0.01 Sn 2.3 0.01

As shown in Table 6, the organic solvent finally recovered according to the present invention can be seen that the concentration of the metal ions are significantly reduced and effectively removed, having a high purity purification performance sufficient for reuse in the semiconductor and display manufacturing process It can be seen that.

The present invention can effectively remove the photoresist, metal ions, and fine particles from the waste solution generated in the semiconductor or liquid crystal display manufacturing process and recover the high-purity organic solvent efficiently, the organic solvent recovered in the semiconductor and display manufacturing process Can be reused to improve process efficiency and reduce process costs.

1 is a configuration diagram briefly showing an example of an organic solvent recovery process apparatus according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100: reservoir tank 101: transfer pump

102, 105: heating tank 103: distillation column

104, 106: condenser 107: reservoir

Claims (8)

In manufacturing a semiconductor or liquid crystal display, in the method for recovering the organic solvent from the waste liquid generated after removing the photoresist, A first distillation step of removing the resist by heating the waste liquid to 40 to 200 ° C. under a pressure of 150 mmHg or less, and A second distillation step of removing water by fractionally distilling the liquid phase from which the resist has been removed at a pressure of 60 mm to 200 ° C. under a pressure of 100 mmHg or less; Including, The waste solution contains 1 to 10% by weight of water-soluble organic amine compound, 20 to 95% by weight of polar aprotic solvent, 0 to 5% by weight of corrosion inhibitor, and 5 to 15% by weight of resist solids. % And moisture content is 0-50% by weight, A method for recovering an organic solvent from a photoresist waste liquid for recovering a mixed organic solvent containing a water-soluble organic amine compound and a polar aprotic solvent from the waste liquid. The method of claim 1, The water soluble organic amine compound is monoethanol amine (MEA), 1-aminoisopropanol (AIP), 2-amino-1-propanol, N-methylaminoethanol (N-MAE), 3-amino-1-propanol, 4- Amino-1-butanol, 2- (2-aminoethoxy) -1-ethanol (AEE), 2- (2-aminoethylamino) -1-ethanol, diethanol amine (DEA), triethanol amine (TEA), And hydroxyethyl piperazine (HEP). A method of recovering an organic solvent from at least one photoresist waste liquid selected from the group consisting of: The method of claim 1, The polar aprotic solvent is N-methylpyrrolidone (NMP), 1,3-dimethyl-2-imidazolidinone (DMI), dimethylsulfoxide (DMSO), dimethylacetamide (DMAc), dimethylformamide ( DMF), N-methylformamide (NMF), tetramethylene sulfone is a method for recovering the organic solvent from the photoresist waste liquid selected from the group consisting of. The method of claim 1, The organic solvent recovered after the second distillation step is a method of recovering the organic solvent from the photoresist waste liquid content of the water-soluble organic amine compound and the polar aprotic solvent is 95 parts by weight or more based on 100 parts by weight of the organic solvent. The method of claim 1, The organic solvent recovered after the second distillation step, the residual content of the photoresist solid content is 0 to 0.01 parts by weight based on 100 parts by weight of the organic solvent, the organic solvent recovery method from the waste liquid. The method of claim 1, The organic solvent recovered after the second distillation step is a method of recovering the organic solvent from the photoresist waste liquid that the residual content of the metal component is 0 to 100 ppb for each metal component. The method of claim 1, The corrosion inhibitor is a method for recovering the organic solvent from at least one photoresist waste liquid selected from the group consisting of compounds represented by the following formula (1), (2) and (3): [Formula 1]

[Formula 2]

(3)

Wherein, R ¹ , R ² are the same as or different from each other, and each independently hydrogen or a hydroxyl group, R ³ is hydrogen, t-butyl group, carboxyl group (-COOH), methyl ester group (-COOCH ₃ ), ethyl ester group (-COOC ₂ H ₅ ) or propyl ester group (-COOC ₃ H ₇ ), R ⁴ is hydrogen or an alkyl group having 1 to 4 carbon atoms, R ⁵ and R ⁶ are the same as or different from each other, and each independently a hydroxyalkyl group having 1 to 4 carbon atoms. The method of claim 1, The first distillation step is carried out under a pressure of 100 mmHg or less, The second distillation step is carried out under a pressure of 30 mmHg or less of the organic solvent recovery method from the waste.

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