KR20180000225A - Recycling device of waste etchant and recycling method of waste etchant - Google Patents

Abstract

The present invention relates to a recycling device for recycling waste etchant and a recycling method of waste etchant by using the recycling device. According to the present invention, the recycling device of waste etchant comprises: an electrolytic bath; a first electrode; an ion permeability precipitation bath; and a second electrode.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recycling apparatus for an etchant waste solution,

The present invention relates to an apparatus for regenerating an etchant waste liquid and a method for regenerating an etchant waste liquid using the apparatus.

Wet etching is a method of etching a target metal on an etch target by injecting an etchant into an etchant having a property of corroding and / or solubilizing only the target metal. The wet etch is used to manufacture a flat panel display, Metal nameplate manufacturing, semiconductor device manufacturing, and the like.

As the wet etching proceeds, the target metal is etched and metal ions are accumulated in the etchant. At this time, when the etchant (hereinafter, referred to as etchant waste solution) in which metal ions are accumulated is continuously used, there is a problem that the metal ions are reduced again to the etch target, and the etching efficiency is lowered. Accordingly, it is required to dispose the etching waste liquid and use a new etching liquid, which causes a decrease in efficiency of use of the etching liquid and causes environmental pollution. Therefore, it is required to increase the etch efficiency and the use efficiency of the etchant, and regenerate the etchant waste in order to minimize environmental pollution.

Conventionally, the regeneration apparatus shown in Fig. 2 has been applied to regenerate the etching waste liquid. The reproducing apparatus includes a first deposition electrode (1); A second deposition electrode (2); A rectifier 3; The etching waste liquid 4 is introduced into the sedimentation tank 5 and an electric current is applied to the etching waste liquid 4 to recover the metal from the etching waste liquid 4, Reproducing apparatus.

However, the conventional regenerator has to cut off the current applied to the etchant waste solution 4 in order to recover the metal, and thus the recovery rate of the metal and the regeneration efficiency of the etchant waste solution 4 are low. That is, the metal ions contained in the etchant waste solution 4 are reduced to the metal 2 for precipitation and precipitated as a metal by application of current to the etchant waste liquid 4, and the current must be cut off in order to recover the metal. , The metal precipitated on the second deposition electrode 2 is reduced again or eliminated on the second deposition electrode 2 and redissolved in the etching waste solution 4 as the current is cut off, The efficiency of regeneration of the etchant waste solution has deteriorated.

In order to solve the problem caused by using such a conventional regenerating apparatus, there has been suggested a technique for improving the regeneration efficiency of the etchant waste solution by increasing the recovery rate of the metal by fixing a separator for selectively passing metal ions into the regenerator . However, since the separation membrane is fixed to the inside of the regenerator, it is difficult to replace the separation membrane when the separation membrane performance deteriorates.

Korean Patent Publication No. 10-0534482

In order to solve the above problems, it is an object of the present invention to provide a reclaiming apparatus for an etchant waste having an excellent recovery rate of a metal and a recycling efficiency of an etchant waste solution.

It is another object of the present invention to provide a method for regenerating an etchant waste solution using the regenerator.

According to an aspect of the present invention, there is provided an electrolytic cell comprising: an electrolytic bath containing an etchant waste liquid; A first electrode disposed inside the electrolytic bath; An ion-permeable dust-collecting tank disposed inside the electrolytic cell and spaced apart from the first electrode, the electrolytic cell containing an electrolyte; And a second electrode disposed inside the ion permeable deposition tank.

Further, the present invention provides a method of manufacturing a semiconductor device, comprising the steps of: a) moving a metal ion in the etchant waste solution into the ion permeable deposition chamber by applying an electric current to a recycling apparatus for the etchant waste fluid filled with the etchant waste solution and the electrolyte; And b) accumulating the metal compound produced by the reaction of the metal ion moved into the ion-permeable precipitation tank with the electrolyte in the ion-permeable precipitation tank.

In the regenerating apparatus of the present invention, since the second electrode is disposed inside the ion permeable deposition tank, when the etchant waste liquid is regenerated by using the same, the metal contained in the etchant effluent can be effectively recovered, thereby improving the regeneration efficiency of the etchant waste liquid.

Further, in the regenerating apparatus of the present invention, since the ion-permeable deposition chamber is detachable from the electrolytic bath, the performance of the ion-permeable deposition chamber can be easily changed.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing a regeneration apparatus for an etchant waste liquid of the present invention. Fig.
2 is a schematic view showing a conventional recycling apparatus for an etchant waste liquid.

Hereinafter, the present invention will be described.

One. Etching Wastewater  Playback device

Referring to FIG. 1, an apparatus for recycling an etchant waste liquid (hereinafter referred to as a "recycling apparatus") of the present invention comprises an electrolytic bath 10; A first electrode (20); An ion-permeable dust collecting tank (30); And a second electrode (40).

An electrolytic bath (10) included in the regenerator of the present invention accommodates the etching waste liquid (11). The first electrode 20, the ion-permeable depositing tank 30, and the second electrode 40 are disposed in the electrolytic bath 10. The electrolytic bath 10 is preferably made of a material which does not react with the etching waste solution 11, and its structure is not particularly limited. The electrolytic bath 10 may also have an inlet (not shown) through which the etching waste liquid 11 flows and an outlet (not shown) through which the etchant waste solution (regenerated etching solution) recovered and recovered from the metal ions is discharged.

The etching waste liquid 11 to be filled in the electrolytic bath 10 is not particularly limited as long as it is a waste liquid generated in the process of etching an object to be etched (for example, a metal film) with an etching liquid. Further, the metal ions accumulated in the etching waste liquid 11 are derived from the etching object, and the metal components contained in the etching liquid are excluded. Specifically, the metal ions accumulated in the etching waste liquid (11) include at least one selected from the group consisting of silver ions, gold ions, copper ions, iron ions, aluminum ions and molybdenum ions.

On the other hand, the etchant is a medium for chemically reacting with an object to be etched to cut off a specific portion of the object, and the composition of the etchant may be determined according to the material to be etched. Specifically, the etching solution contains at least one selected from the group consisting of nitric acid, phosphoric acid, acetic acid, hydrogen peroxide, a co-oxidant, a surfactant, a pH adjuster, a chelating agent, an amine compound, a buffer solution, a sequestering agent, Lt; / RTI >

Examples of the etching solution having the above composition include 1 to 20% by weight of hydrogen peroxide, 0.1 to 4% by weight of a pH adjusting agent, 0.1 to 5% by weight of a chelating agent, 0.01 to 3% by weight of a cyclic amine compound, and water 72 To 98.79% by weight; 1 to 20% by weight of a nitric acid, 50 to 75% by weight of phosphoric acid, 1 to 20% by weight of a nitric acid, 0.5 to 3% by weight of an auxiliary oxide solubilizer, 0.001 to 0.01% And a composition comprising water in a remaining amount.

The first electrode 20 included in the reproducing apparatus of the present invention is disposed inside the electrolytic bath 10 and is an electrode having lower reductivity than the second electrode 40. It is preferable that the first electrode 20 is made of an insoluble metal which is not dissolved in the etching waste solution 11 filled in the electrolytic bath 10. Specifically, the first electrode 20 may include a metal selected from the group consisting of gold (Au), platinum (Pt), and iridium (Ir), or may be made of an alloy thereof.

The ion-permeable depositing tank 30 included in the regenerator of the present invention is disposed inside the electrolytic bath 10 so as to be spaced apart from the first electrode 20 and accommodates the electrolytic 31 therein. The ion permeable tundish (30) serves as a compartment for preventing the second electrode (40), in which metal ions are reduced and metal is precipitated, from coming into direct contact with the etching waste solution (11) filled in the electrolytic bath do. It is preferable that the ion-permeable septic tank 30 is made of an ion exchange separator which selectively permeates a cation or an anion. The metal ions contained in the etching waste liquid 11 are moved into the iontophoretic deposition tank 30 and are collected and collected in the second electrode 40 so that the metal is reduced And the precipitation reaction can be enhanced.

The ion exchange separation membrane is not particularly limited, but it may be a membrane type membrane having a thickness of about 100 to 200 mu m. In addition, the ion exchange membrane may selectively use a cation exchange membrane or an anion exchange membrane depending on the metal ion to be permeated. The cation exchange membrane has an electrically negative charge (e.g., SO ₃ ^2- ), so that the cation is passed by electrostatic attraction but the anion does not pass due to the electrostatic repulsion. On the contrary, the anion exchange membrane has a positive charge (for example, NH ^{4 +} ), so that only the negative ions are selectively passed through the above electrostatic principle.

It is preferable that the ion-permeable depositing tank 30 made of such an ion exchange separating membrane is disposed (coupled) so as to be detachable (detached and attached) inside the electrolyzer. When the performance of the ion-permeable deposition chamber 30 is deteriorated due to the detachment of the ion-permeable deposition chamber 30, the ion permeable deposition chamber 30 can be easily replaced, .

That is, there has been an attempt to regenerate the etchant waste by using a regenerating apparatus in which a separator is disposed. However, when the separator is fixedly coupled to the inside of the electrolyzer of the regenerator (for example, When the performance of the separator deteriorates, it is difficult to replace the separation membrane, and the use efficiency of the regenerator is lowered.

However, according to the present invention, since the ion permeable deposition chamber 30 can be detached from the electrolyzer 10, even if the performance of the ion permeable deposition chamber 30 deteriorates, it can be easily replaced.

On the other hand, the electrolyte 31 filled in the iontophoretic deposition tank 30 is reacted with the metal ions (metal ions accumulated in the etchant waste liquid 11) moved to the inside of the iontophoretic deposition tank 30 Thereby forming a metal compound. The electrolyte 31 is not particularly limited, but preferably includes at least one selected from the group consisting of sulfur ions, chlorine ions, iodine ions, sulfate ions, and carbonate ions. Specifically, sodium chloride, sodium iodide, sodium sulfate, sodium carbonate and the like can be used as the electrolyte (31).

The second electrode (40) included in the regenerator of the present invention is disposed inside the ion permeable deposit tank (30). In this second electrode (40), the reduction and precipitation reaction of the metal ions accumulated in the etching waste liquid (11) occurs. The material of the second electrode 40 is not particularly limited and may include a metal selected from the group consisting of gold (Au), silver (Ag), platinum (Pt), iridium (Ir) , And alloys thereof.

The reproducing apparatus of the present invention may further include a rectifier 50 connected to the first electrode 20 and the second electrode 40 to control current flow. This is because the current is more easily applied to the first electrode 20 and the second electrode 40 as the rectifier 50 is further included. The rectifier 50 may be selected from those known in the art.

The regenerator of the present invention is provided with the ion-permeable deposition chamber 30 for storing the electrolyte 31 even when the current applied to the first electrode 20 and the second electrode 40 is cut off. The recycling efficiency of the etching waste liquid 11 is excellent.

That is, since the ion-permeable depositing tank 30 is made of an ion exchange separating membrane which selectively permeates ions, the metal ions accumulated in the etching waste liquid 11 permeate through the ion-permeable depositing tank 30 and move into the interior thereof And the transferred metal ions can not move to the outside due to the characteristics of the ion exchange membrane constituting the ion permeable deposit chamber 30. [ Accordingly, even if the current applied to the first electrode 20 and the second electrode 40 is cut off, the metal ions migrating into the ion-permeable deposition chamber 30 are blocked from moving to the etchant waste solution 11, 11), the present invention can improve the regeneration efficiency of the etchant waste solution 11. [

In addition, since the electrolyte 31 reacting with the metal ions is filled in the ion-permeable depositing tank 30, the metal ions migrating into the ion-permeable depositing tank 30 are precipitated and / or precipitated into the metal compound, The invention can increase the recovery rate of the metal.

2. Etching Wastewater  How to play

The present invention provides a method of regenerating an etchant waste liquid using the regenerator, which will be described in detail as follows.

a) Current application

The metal ions in the etchant waste liquid 11 are moved to the inside of the ion permeable deposit tank 30 by applying a current to the regenerator charged with the etchant waste fluid 11 and the electrolyte 31. [

At this time, the intensity of the current applied to the reproducing apparatus is not particularly limited, but is preferably 1 to 5 A. If the current intensity is less than 1 A, the reduction and precipitation of metal ions may be reduced. If the current intensity exceeds 5 A, the physical properties of the etchant waste solution 11 are changed due to the decomposition reaction of the etchant waste solution 11, It is difficult to reuse the etchant waste solution 11. [

Also, the intensity of the voltage applied to the reproducing apparatus is not particularly limited, but is preferably 0.5 to 5 V. If the voltage is less than 0.5 V, reduction and precipitation of the metal ions may be reduced. If the voltage exceeds 5 V, the physical properties of the etchant waste solution 11 may change due to the decomposition reaction of the etching waste solution 11, It is difficult to reuse the etchant waste solution 11. [

On the other hand, the metal ions migrating from the etching waste liquid 11 into the ion permeable tundish 30 are blocked from moving to the etching waste liquid 11 due to the characteristics of the ion permeable tundish 30 composed of an ion exchange separation membrane , Whereby the concentration of the metal ions accumulated in the etching waste solution 11 decreases. At this time, the metal ions are generated in the etching process and accumulated in the etching waste solution 11, and include at least one selected from the group consisting of silver ions, gold ions, copper ions, iron ions, nickel ions, aluminum ions and molybdenum ions .

b ) Accumulation of metal compounds

Next, the metal ions migrated into the ion-permeable depositing tank 30 and the metal compound generated by the reaction of the electrolyte 31 are accumulated in the ion-permeable depositing tank 30. In other words, the electrolyte 31 capable of reacting with metal ions is filled in the ion-permeable depositing tank 30, and the metal ions react with the electrolyte 31 to deposit and precipitate the metal compound.

Meanwhile, the method for regenerating the etchant waste liquid of the present invention may further comprise the step (c) of separating the ion-permeable depositing tank 30 from the regeneration apparatus and taking out the metal compound accumulated therein. Specifically, the current applied to the regenerator is cut off, the ion permeable septic tank 30 is separated, and the metal compound is taken out.

In addition, the method of regenerating the etchant waste liquid of the present invention may further include the step of replacing the ion permeable deposit tank 30 to improve the use efficiency of the regenerator (step (d)). That is, when deterioration of the performance of the ion permeable deposit tank 30 occurs during the regeneration process, the ion permeable deposit tank 30 is newly replaced to improve the use efficiency of the regenerator.

The metal compound obtained by the method for regenerating the etchant waste liquid of the present invention and the etchant waste liquid recovered by removing the metal ion are collected and reused.

Hereinafter, the present invention will be described in detail with reference to examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.

[ Example  One]

(Composition: 60 wt% of phosphoric acid + 5 wt% of nitric acid + 10 wt% of acetic acid + remaining amount of DIW) was charged into an electrolytic bath of a regenerator having the structure of Fig. 1, and a voltage of 0.5 V for 5 minutes. At this time, the ion permeable precipitation tank was composed of a cation exchange membrane, and 10 wt% of sodium chloride (NaCl) was used as an electrolyte to be filled in the ion permeable septic tank.

[ Example  2]

The etching waste solution was regenerated under the same conditions as in Example 1 except that the process of regenerating the etching waste solution for 5 minutes was repeated five times.

[ Comparative Example  One]

The etching waste liquid was regenerated under the same conditions as in Example 1, except that the etching waste solution was fed into the regeneration tank of the regenerator having the structure shown in Fig. 2 (i.e., the ion permeable deposition tank and no electrolyte).

[ Comparative Example  2]

The etching waste solution was introduced into a regenerating apparatus in which the cation exchange membrane was bonded along the wall and bottom of the electrolytic cell so that the inside of the electrolytic cell was separated into the first and second spaces and the etching waste solution was regenerated for 25 minutes under a voltage of 0.5 V. At this time, the same etching waste solution as used in Example 1 was used and charged into the first space of the electrolytic cell. Further, 10 wt% of sodium chloride (NaCl) was filled in the second space of the electrolytic cell with the electrolyte.

[ Experimental Example  One]

The dissolved etchant recovered through Examples 1 and 2 and Comparative Examples 1 and 2 was recovered and the dissolved silver (Ag) concentration and the silver (Ag) removal amount in the etchant were measured. The results are shown in Table 1 below.

Etching waste solution [wt%] Voltage
(V) Electrolyte Play time
(min) Dissolved Ag Concentration (ppm) Ag removal amount
(ppm) Phosphoric acid nitric acid Acetic acid DIW  Etching waste liquid before regeneration 60 5 10 Balance - - - 1029 - Example 1 60 5 10 Balance 0.5 NaCl 10wt% 5 minutes 976 53 Example 2 60 5 10 Balance 0.5 NaCl 10wt% 25 minutes 818 211 Comparative Example 1 60 5 10 Balance 0.5 - 5 minutes 1014 15 Comparative Example 2 60 5 10 Balance 0.5 NaCl 10wt% 25 minutes 962 67

Referring to Table 1, it can be seen that the recycling efficiency of the etchant waste solution and the recovery rate of silver (Ag) are high by regenerating the etching waste solution using the regenerator of the present invention.

10: electrolytic cell
11: etching waste liquid
20: first electrode
30: ion permeable deposition chamber
31: electrolyte
40: second electrode
50: rectifier

Claims (14)

An electrolytic bath containing an etching waste solution;
A first electrode disposed inside the electrolytic bath;
An ion-permeable dust-collecting tank disposed inside the electrolytic cell and spaced apart from the first electrode, the electrolytic cell containing an electrolyte;
And a second electrode disposed inside the ion-permeable deposition tank. The method according to claim 1,
Wherein the ion permeable deposition vessel is made of an ion exchange separation membrane. The method according to claim 1,
Wherein the ion permeable deposition chamber is disposed so as to be detachable inside the electrolytic bath. The method according to claim 1,
The etchant waste liquid contains metal ions accumulated by an etching process,
Wherein the metal ion is at least one selected from the group consisting of silver ion, gold ion, copper ion, iron ion, nickel ion, aluminum ion and molybdenum ion. The method according to claim 1,
Wherein the electrolyte comprises at least one selected from the group consisting of a sulfur ion, a chloride ion, an iodide ion, a sulfate ion, and a carbonate ion. The method according to claim 1,
Wherein the first electrode comprises at least one selected from the group consisting of gold, platinum, and iridium. The method according to claim 1,
Wherein the second electrode comprises at least one selected from the group consisting of gold, silver, platinum, iridium, and aluminum. The method according to claim 1,
And a rectifier connected to the first electrode and the second electrode. a) moving metal ions in the etchant waste solution into the ion permeable deposition chamber by applying an electric current to a reclaiming device for the etchant waste solution of claim 1 filled with the etchant waste solution and the electrolyte; And
b) accumulating the metal compound produced by the reaction of the metal ion moved into the ion permeable deposition tank with the electrolyte in the ion permeable deposition tank. The method of claim 9,
c) separating the ion-permeable deposit tank from the regenerator to take out the metal compound accumulated therein. The method of claim 10,
and d) replacing the ion-permeable segregation tank. The method of claim 9,
The metal ions are accumulated in the etching waste solution during the etching process,
Wherein the metal ion is at least one selected from the group consisting of silver ion, gold ion, copper ion, iron ion, nickel ion, aluminum ion and molybdenum ion. The method of claim 9,
Wherein the intensity of the current applied to the reproducing apparatus is 1 to 5 A. The method of claim 9,
Wherein the intensity of the voltage applied to the reproducing apparatus is 0.5 to 5 V.

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