KR102223889B1 - Measuring device for concentration of additive breakdown product in plating solution - Google Patents

Abstract

The present invention relates to a measurement method, an electrochemical measurement cell, and a measurement device which can directly and continuously measure concentration of a monovalent copper ion (Cu^+), 3-mercaptopropyl sulfonate (MPS), or Cu^+-MPS which are decomposition products of a plating additive contained in a plating solution during a copper plating process.

Description

Measuring device for concentration of additive breakdown product in plating solution

The present invention relates to an apparatus for measuring the concentration of an additive decomposition product contained in a plating solution. ^{In more detail, the present invention is a monovalent copper ion (Cu +} ), 3-mercaptopropyl sulfonate (MPS), or Cu ⁺ -MPS, which is a decomposition product of the plating additive included in the plating solution during the copper plating process. It relates to a measuring method, an electrochemical measuring cell, and a measuring device capable of directly and continuously measuring the concentration.

Copper electrolytic plating solutions generally contain copper sulfate, sulfuric acid, chlorine ions, and organic additives. The organic additives are included to improve plating performance, and include accelerators, moderators, and levelers. The accelerator serves to accelerate deposition in vias and trenches during bottom up filling. Sodium sulfopropyl disulfide (SPS) has been used as a representative accelerator.

Meanwhile, in the copper electrolytic plating solution, the performance of the plating solution deteriorates over time, and thus various defects such as voids and pinholes in the plating film may occur. Deterioration of the copper electrolytic plating solution may have various causes, such as decomposition of organic additives and inflow of impurities.

For example, in the plating solution, SPS is subjected to an electrochemical/chemical side reaction, such as 3-mercaptopropyl sulfonate (MPS) and propane disulfonic acid (PDS), as shown in the following reaction formula. Decomposition products are produced.

[Scheme 1]

[Scheme 2]

^{_{SPS 2- + O 2 + H 2}} O → PDS 2- + MPSA - + H +

[Scheme 3]

_{^{SPS 2- + 6H 2 O → 2PDS}} 2- + 10e - + 12H +

In this way, the performance of the plating solution decreases due to the decrease in the concentration of SPS in the plating solution and an increase in decomposition products such as MPS. Accordingly, a method of measuring the SPS concentration for plating solution performance diagnosis and plating solution management is known.

Conventionally, the cathode current representing the plating speed according to the additive concentration and the stripping charge proportional to this are measured by the CVS (cyclic voltammetric stripping) method, which is a plating additive analysis method using a rotating disk electrode. Thus, the concentrations of SPS and MPS were measured indirectly. According to the above method, there is a problem in that the cathode electrode is exposed every time the sample is replaced in order to analyze the sample, and since it is not a method of directly measuring the MPS concentration, there is a limitation that it is complicated and the accuracy is low.

As a background technology of the present invention, Korean Patent No. 10-1711293 describes a method of measuring the concentration of an accelerator contained in a plating solution using a cyclic voltammetry method.

An object of the present invention is to provide a method capable of directly and continuously measuring the concentration ^{of monovalent copper ions (Cu +} ) contained in a plating solution during a plating process.

An object of the present invention is to provide a method for directly and continuously measuring the concentration ^{of MPS or Cu +} -MPS, which is an additive decomposition product contained in a plating solution, during a plating process.

An object of the present invention is to provide a plating solution performance monitoring method capable of diagnosing plating defects in advance by monitoring plating solution performance in real time during a plating process, and improving plating efficiency.

An object of the present invention is to provide an electrochemical measuring cell having an electrode structure capable of directly and continuously measuring the concentration ^{of monovalent copper ions (Cu +} ), which is a decomposition product of a plating additive contained in a plating solution during a plating process.

An object of the present invention is to provide an electrochemical measuring cell having an electrode structure capable of directly and continuously measuring the concentration ^{of MPS or Cu +} -MPS, which is an additive decomposition product contained in a plating solution, during a plating process.

An object of the present invention is to provide a measuring device capable of directly and continuously measuring the concentration of a plating additive contained in a plating solution during a plating process.

Other objects and advantages of the present invention will become more apparent by the following detailed description, claims and drawings.

According to an aspect, a selection valve capable of selectively supplying at least one of a reference plating solution and a sample plating solution; A microflow cell including a supply unit to which the plating solution supplied through the selection valve is supplied and a discharge unit from which the supplied plating solution is discharged; A working electrode in contact with the plating solution accommodated in the microflow cell; A reference electrode used as a reference when determining the potential of the working electrode in contact with the plating solution accommodated in the microflow cell; A counter electrode in contact with the plating solution accommodated in the microflow cell; And a detection unit capable of detecting a change in current of the working electrode, wherein the working electrode is made of a noble metal thin film as an anode electrode, and an electrochemical measurement for measuring the anode current at the working electrode to detect the additive component of the plating solution The device is provided.

The plating solution may be supplied directly from the plating bath during plating.

The plating solution may be supplied after being collected from a plating bath to be analyzed.

The electrochemical measuring apparatus may further include a control unit that controls the supply of the plating solution to the microflow cell, receives a signal from the measurement unit, detects an additive component of the plating solution, and monitors the performance of the plating solution.

The control unit may control addition of the additive component to the plating solution.

The electrochemical measuring device may further include a current generating unit for flowing a current having a constant current density between the working electrode and the counter electrode.

The electrochemical measuring device includes, together with the reference plating solution or sample plating solution, a wire connector for supplying at least one of a signal enhancing agent capable of enhancing a detection signal and a noise removing agent capable of removing noise of a detection signal to the microflow cell ( Y-connector) may further include.

The electrochemical measuring device may include at least one of the micro flow cells; And one or more measuring units matched to the micro flow cell.

The working electrode may be Au or a noble metal alloy thereof, or a surface coated with Au or a noble metal alloy thereof, or a nanoparticle-shaped Au or a noble metal alloy thereof may be supported.

The reference plating solution may contain copper sulfate, sulfuric acid, and hydrochloric acid.

The additive may be one or more of an accelerator, a moderator, and a leveler.

The additive may include sodium sulfopropyl disulfide (SPS).

The electrochemical measuring device may measure the concentration of the additive decomposition product.

The additive decomposition product may be a monovalent copper ion.

The additive decomposition product may be 3-mercaptopropyl sulfonate (MPS).

The additive decomposition product may be ^{Cu + -MPS.}

The anode current measurement may be performed using chronoamperometry, slow scan Linear Sweep Voltammetry (LSV), or slow scan cyclic voltammetry (CV).

^{According to an embodiment, the concentration of monovalent copper ions (Cu +} ), which is an additive decomposition product included in the plating solution during the plating process, may be directly and continuously measured.

According to an embodiment, during the plating process, the plating solution performance is monitored in real time to detect plating defects and improve plating efficiency.

Accordingly, deterioration of the plating solution can be diagnosed early, thereby minimizing plating defects and damages.

According to an embodiment, the concentration of the plating additive included in the plating solution during the plating process may be directly and continuously measured.

According to an embodiment, a concentration of a plating additive may be more accurately measured by mixing a material capable of enhancing a plating additive detection signal.

According to an embodiment, at least one microflow cell and a measuring unit may be provided to simultaneously measure and analyze concentrations of various plating additives.

1 is a flowchart schematically illustrating a method of measuring the concentration of an additive decomposition product contained in a plating solution during a plating process according to an embodiment of the present invention.
FIG. 2 is a schematic diagram of an electrochemical measurement cell having an electrode structure capable of directly and continuously measuring a concentration of a decomposition product of a plating additive included in a plating solution during a plating process according to an embodiment of the present invention.
FIG. 3 is a schematic diagram of a structure diagram of an electrochemical measuring device capable of directly and continuously measuring the concentration of a plating additive contained in a plating solution during a plating process according to an embodiment of the present invention.
FIG. 4A is a schematic structural diagram of an electrochemical measuring device capable of directly and continuously measuring a concentration of a plating additive contained in a plating solution during a plating process according to another embodiment of the present invention.
4B is a diagram schematically showing the structure of an electrochemical measuring device capable of directly and continuously measuring the concentration of a plating additive contained in a plating solution during a plating process according to another embodiment of the present invention.
5A is a graph showing the current change by concentration of MPS when the working electrode of the electrochemical measurement cell is Au.
5B is a graph showing the current change by concentration of MPS when the working electrode of the electrochemical measurement cell is Pt.
5C is a graph showing the current change by concentration of MPS when the working electrode of the electrochemical measurement cell is stainless steel SUS304.
6A is a graph showing changes in current for each concentration of MPS when the scan speed is 10 mV/s in the electrochemical measuring device.
6B is a graph showing the current change by concentration of MPS when the scan speed is 50 mV/s in the electrochemical measuring device.
6C is a graph showing the current change by concentration of MPS when the scan speed is 100mV/s in the electrochemical measuring device.
7 is a graph showing a calibration curve according to MPS concentration by a method of measuring the concentration of an additive decomposition product contained in a plating solution according to an embodiment of the present invention.
8A is a graph showing the CV result according to the MPS concentration according to the method for measuring the concentration of an additive decomposition product contained in the plating solution according to an embodiment of the present invention.
8B is a graph showing the current density according to the MPS concentration according to the method for measuring the concentration of an additive decomposition product contained in the plating solution according to an embodiment of the present invention.
9A is a graph showing the results of analyzing deterioration of the plating solution through current density change for each potential by the method of measuring the concentration of an additive decomposition product contained in the plating solution according to an embodiment of the present invention after SPS or PEG is added to the plating solution.
9B is a graph showing the results of analyzing deterioration of the plating solution through current density change over time by the method of measuring the concentration of an additive decomposition product contained in the plating solution according to an embodiment of the present invention after adding SPS and PEG to the plating solution.
10A is a graph showing a result of measuring a current over time according to a method for measuring a concentration of an additive decomposition product contained in a plating solution according to an embodiment of the present invention.
10B is a graph showing MPS concentration over time using a calibration curve derived by a method for measuring concentration of an additive decomposition product contained in a plating solution according to an embodiment of the present invention.

Objects, specific advantages, and novel features of the present disclosure will become more apparent from the following detailed description and embodiments in conjunction with the accompanying drawings.

Prior to this, terms or words used in the present specification and claims should not be interpreted in a conventional and dictionary meaning, and the inventor may appropriately define the concept of terms in order to describe his own invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of the present disclosure based on the principle that there is.

In this specification, when a component such as a layer, portion, or substrate is described as being “on”, “connected”, or “coupled” to another component, it is directly “on”, “on” the other component. It may be connected" or "coupled", and may be interposed between one or more other components. In contrast, if a component is described as being "directly over", "directly connected", or "directly coupled" of another component, no other component can be interposed between the two components. .

The terms used in this specification are used only to describe specific embodiments, and are not intended to limit the present disclosure. Singular expressions include plural expressions unless the context clearly indicates otherwise.

In the present specification, terms such as'include' or'have' are intended to designate the presence of features, numbers, steps, actions, components, parts, or a combination thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof does not preclude in advance.

In the present specification, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless otherwise stated. In addition, throughout the specification, "on" means to be positioned above or below the target portion, and does not necessarily mean to be positioned above the direction of gravity.

In the present disclosure, since various transformations can be applied and various embodiments can be provided, specific embodiments will be illustrated in the drawings and will be described in detail in the detailed description. However, this is not intended to limit the present disclosure to a specific embodiment, it is to be understood as including all conversions, equivalents, and substitutes included in the spirit and scope of the present disclosure. In describing the present disclosure, when it is determined that a detailed description of a related known technology may obscure the subject matter of the present disclosure, a detailed description thereof will be omitted.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings, and in the description with reference to the accompanying drawings, the same or corresponding constituent elements are assigned the same reference numbers, and redundant descriptions thereof will be omitted. do.

1 is a flowchart schematically illustrating a method of measuring the concentration of an additive decomposition product contained in a plating solution during a plating process according to an embodiment of the present invention.

As shown in FIG. 1, the method for measuring the concentration of an additive decomposition product contained in the copper plating solution of the present invention includes the following steps.

I-i) supplying a reference plating solution to a micro flow cell (step S100);

I-ii) measuring an anode current of the reference plating solution (step S110);

I-iii) supplying a copper plating solution containing an additive to the microflow cell (step S120);

I-iv) measuring the anode current of the copper plating solution (step S130); And

I-v) measuring the concentration of the additive decomposition product contained in the copper plating solution based on the change in anode current (step S140).

In step S100, the reference plating solution may include copper sulfate, sulfuric acid, and hydrochloric acid. Although not limited thereto, the amount of copper ions may be in the range of 2g/L-250g/L, and the amount of sulfuric acid may be in the range of 10g/L -200g/L. The amount of chlorine ions may be in the range of 1 mg/L-1 g/L. The optimum amount of each component can be adjusted in consideration of the performance of the precursor copper plating solution.

In step S110, a known technique may be used to measure the anode current. In the reference plating solution, it is necessary to measure the anode current of the reference plating solution in order to suppress the generation of current due to the reduction reaction of ^{copper ions (Cu 2 +) and also detect very minute changes in current.}

In step S120, the copper plating solution containing the additive may be supplied from a plating bath during plating. With the above configuration, it is possible to continuously monitor the performance of the plating bath in real time.

The present invention measures the anode current by directly inducing the oxidation reaction of the substance to be analyzed, unlike the prior art in which the concentration of the additive is indirectly detected by measuring the reduction and oxidation rate of ^{copper ions (Cu 2 +} ) according to the concentration of the additive. Thus, it is possible to solve the problem that the resolution decreases according to the change in the concentration of other substances in the sample.

The concentration of the additive decomposition product may be a monovalent copper ion concentration.

Unlike the prior art, the present invention is a method of directly measuring the anode current of the working electrode, and the concentration of monovalent copper ions in the plating solution supplied to the microflow cell can be directly measured.

The additive is sodium sulfopropyl disulfide (SPS), and the decomposition product may be 3-mercaptopropyl sulfonate (MPS) or Cu ⁺ -MPS.

In the present invention, unlike the prior art in which the MPS concentration is inferred by measuring SPS, the concentration of MPS, which is a decomposition product of SPS, can be directly measured, so that the performance of the copper plating solution can be more accurately monitored.

In the present invention, the current change measurement is not particularly limited as long as the Faraday current can be measured. Although not limited thereto, a time-to-current method (chronoamperometry), a slow scan linear sweep voltammetry (LSV), or a slow scan rotation potential method (slow scan cyclic voltammetry (CV)) may be used. However, it may be difficult to measure with fast scan LSV, chronopotentionmetry, or OCP.

Although not limited thereto, when measuring the current change, a scan speed of 1-50 mV/s may be suitable. When the scan speed exceeds 50 mV/s, charging current, which is noise, increases, and thus, it may be difficult to calculate a calibration curve.

The concentration of the additive decomposition product contained in the copper plating solution may be measured based on the change in anode current using the calibration curve previously calculated in step I-v).

According to the above configuration, it is possible to accurately and quickly measure the concentration of an additive decomposition product contained in the copper plating solution.

The method of calculating the calibration curve may include the following steps.

Supplying a reference plating solution to the microflow cell and then measuring a current by applying a potential;

Measuring a current by supplying a copper plating solution containing an additive to the microflow cell through a selection valve after a predetermined period of time and applying an electric potential to the microflow cell; And

A step of measuring a current by supplying a reference plating solution to a microflow cell and then applying a potential. In the step, a calibration curve may be calculated using the peak current or the peak area according to the additive concentration.

In addition, the method of calculating the calibration curve may include the following steps.

Supplying a reference plating solution to the microflow cell and then applying a predetermined range of electric potential to scan the electric potential to measure a current; And

A step of measuring a current by supplying a copper plating solution containing an additive to a microflow cell through a selection valve and scanning a potential, in which a calibration curve is calculated using the current density according to the additive concentration at a preset potential. I can.

Although not limited thereto, the potential scan range may be preferably 0.3 V-1.2 V (vs. Ag/AgCl (sat. KCl)). This is because side reactions that may occur when the potential is out of range may increase measurement errors. For example, a reduction reaction of divalent copper at a potential of less than 0.3 V (vs. Ag/AgCl (sat. KCl)), and oxidation of the electrode at a potential of more than 1.2 V (vs. Ag/AgCl (sat. KCl)) Reactions and water decomposition reactions can increase measurement errors.

The copper plating solution performance monitoring method of the present invention includes the following steps.

II-i) supplying a reference plating solution to a micro flow cell;

II-ii) measuring an anode current of the reference plating solution;

II-iii) supplying a copper plating solution containing an additive used in a plating process to the microflow cell;

II-iv) measuring the anode current of the copper plating solution;

II-v) measuring the concentration of an additive decomposition product contained in the copper plating solution based on the change in anode current; And

II-vi) Evaluating the performance of the copper plating solution based on the measured concentration of the additive decomposition product.

The copper plating solution may be directly supplied from a plating bath during plating.

According to the configuration of the present invention, the performance of the copper plating solution can be directly and accurately and continuously monitored.

The plating solution may be supplied after being collected from a plating bath to be analyzed.

The copper plating solution performance monitoring method of the present application may further include II-vii) adding an additive based on the change in the anode current.

According to the configuration of the present invention, the deterioration of the plating solution can be diagnosed at an early stage, and the performance of the plating solution can be optimally maintained, thereby minimizing plating defects and damages.

FIG. 2 is a schematic diagram of an electrochemical measurement cell having an electrode structure capable of directly and continuously measuring a concentration of a decomposition product of a plating additive included in a plating solution during a plating process according to an embodiment of the present invention.

Referring to FIG. 2, the electrochemical measurement cell 100 of the present invention comprises: a microflow cell including a supply unit 112 from which a plating solution is supplied and a discharge unit 114 from which the plating solution is discharged; A working electrode 120 in contact with the plating solution accommodated in the microflow cell; A reference electrode 130 serving as a reference when determining the potential of the working electrode 120 in contact with the plating solution accommodated in the microflow cell; And a counter electrode 140 in contact with the plating solution accommodated in the microflow cell.

The working electrode 120 is an electrode that exchanges electrons with chemical species in the copper plating solution.

The working electrode 120 is an anode electrode made of a noble metal thin film, and the anode current is measured at the electrode to detect the concentration of an additive decomposition product in the copper plating process.

By the above configuration, the present invention is a method of directly measuring the anode current of the working electrode 120, unlike the prior art, and the concentration of ^{monovalent copper ions, MPS, and/or Cu + -MPS in the plating solution supplied to the microflow cell.} It can be measured directly.

The working electrode 120 has a concept of an electrochemically active surface area (ECSA), and may have a thin film shape rather than a porous structure.

The working electrode 120 may be Au or a noble metal alloy thereof, or a surface coated with Au or a noble metal alloy thereof, or a nanoparticle-shaped Au or a noble metal alloy thereof may be supported.

Although not limited thereto, the working electrode 120 may include an electrode in the form of a thin film of a noble metal alloy such as Au or Au-Pt, Au-Pd, Au-Ru, or Au-Ir; An electrode in the form of a thin film of Au/Pt, Au/Pd, Au-Ru, or Au/Ir whose contact surface with the plating solution is Au; Alternatively, it may be suitable that the Au nanoparticles are an electrode coated or supported on the surface of a noble metal thin film that is a contact surface with the plating solution. With the above configuration, the electrocatalytic activity is excellent and the current density is large, so that the measurement of the decomposition product of the additive can be accurately and quickly.

The working electrode 120 may be electrically connected to the current generating unit while being connected to the conducting wire.

The reference electrode 130 is an electrode used as a reference when determining the potential of the working electrode 120. As the material of the reference electrode 130, for example, saturated calomel (Hg/Hg ₂ Cl ₂ ) or silver/silver chloride (Ag/AgCl) may be used.

The counter electrode 140 is an electrode for causing a current to flow through the copper plating solution between the working electrodes 120 and causing a reaction at the interface between the electrode and the copper plating solution. As the counter electrode 140, for example, a copper electrode as a soluble electrode, or a platinum, SUS, iridium, iridium oxide, coated titanium electrode, or the like as an insoluble electrode can be used.

The additive is sodium sulfopropyl disulfide (SPS), and the decomposition product may be 3-mercaptopropyl sulfonate (MPS) or Cu ⁺ -MPS.

In the present invention, unlike the prior art in which the concentration of SPS and MPS is inferred by measuring the effect of accelerating the copper plating speed of SPS and MPS, the concentration of MPS, which is a decomposition product of SPS, can be directly measured. Can be monitored.

The copper plating solution containing the additive may be supplied from a plating bath during plating. With the above configuration, it is possible to continuously monitor the performance of the plating bath in real time.

FIG. 3 is a schematic diagram of a structure diagram of an electrochemical measuring device capable of directly and continuously measuring the concentration of a plating additive contained in a plating solution during a plating process according to an embodiment of the present invention.

Referring to Figure 3, the electrochemical measuring device of the present invention is largely a supply member 200; Measuring cell 100; Measuring unit 300; And a control unit 400.

The supply member 200 includes a supply line 210 of a reference plating solution and a sample plating solution; A selection valve 220 capable of selectively supplying a plating solution or the like; And a pump 230 for guiding the plating solution or the like to the measurement cell 100.

A base solution, a sample, a plating solution sample, or a reference plating solution of various other components may be continuously supplied to the measurement unit 300 through the supply member 200 without exposure of the electrode to the air. According to the above configuration, errors due to exposure of the electrodes in the air can be reduced, and the concentration of the target material can be more accurately measured.

Referring to FIG. 2, the measurement cell 100 is a microflow cell including a supply unit 112 for supplying a plating solution supplied through the selection valve 220 and a discharge unit 114 for discharging the supplied plating solution. ; A working electrode 120 in contact with the plating solution accommodated in the microflow cell; A reference electrode 130 serving as a reference when determining the potential of the working electrode 120 in contact with the plating solution accommodated in the microflow cell; And a counter electrode 140 in contact with the plating solution accommodated in the microflow cell. The working electrode 120 is made of a noble metal thin film as an anode electrode, and the anode current is measured by the working electrode 120 to detect the additive component of the plating solution.

It may include a current generating unit that allows a current to flow between the working electrode 120 and the counter electrode 140 with a constant current density.

The measurement unit 300 may detect a change in current of the working electrode 120.

The control unit 400 controls the supply of the plating solution to the microflow cell, receives a signal from the measurement unit 300 and detects an additive component of the plating solution to monitor the performance of the plating solution. With the above-described configuration, it is possible to diagnose deterioration of the plating solution early and maintain the performance of the plating solution optimally, thereby minimizing plating defects and damages resulting therefrom.

The control unit 400 may control addition of an additive component to the plating solution. According to the configuration of the present invention, the deterioration of the plating solution can be diagnosed at an early stage, and the performance of the plating solution can be optimally maintained, thereby minimizing plating defects and damages.

FIG. 4A is a schematic structural diagram of an electrochemical measuring device capable of directly and continuously measuring a concentration of a plating additive contained in a plating solution during a plating process according to another embodiment of the present invention. 4B is a diagram schematically showing the structure of an electrochemical measuring device capable of directly and continuously measuring the concentration of a plating additive contained in a plating solution during a plating process according to another embodiment of the present invention.

The electrochemical measuring device of FIG. 4A differs from the electrochemical measuring device of FIG. 3 in that the pump 230 ′ is a multi-channel pump and further includes a wire connector 240. Hereinafter, detailed descriptions of overlapping configurations will be omitted.

With the above configuration, together with at least one of the reference plating solution and the sample plating solution, at least one of a signal enhancer capable of enhancing the detection signal and a noise removing agent capable of removing noise of the detection signal can be supplied to the microflow cell.

The electrochemical measurement device of FIG. 4B includes at least one microflow cell (100a, 100b, 100c) compared to the electrochemical measurement device of FIG. 4A; And one or more measuring units 300a, 300b, and 300c matching the micro flow cells 100a, 100b, and 100c. Hereinafter, detailed descriptions of overlapping configurations will be omitted.

According to the above configuration, it is possible to simultaneously measure and analyze the concentration of various plating additives by providing at least one microflow cell and a measuring unit.

The additive may be one or more of an accelerator, a moderator, and a leveler. With the above configuration, it is possible to directly and continuously accurately measure the concentration of various additives.

Hereinafter, the present invention will be described in more detail through examples. However, these examples are for illustrative purposes only, and the scope of the present invention will not be construed as being limited by these examples.

[ Example ]

1. Plating solution additive according to the working electrode Decomposition products Measure

One) Example 1 and Comparative example 1, 2

The anode current was measured by varying the working electrode of the electrochemical measurement cell of the present invention. To measure the anode current, Example 1 used an Au electrode as a working electrode, Comparative Example 1 used a Pt electrode as a working electrode, and Comparative Example 2 used a SUS304 electrode made of stainless steel as the working electrode. , The following experimental conditions and experimental procedures were used.

2) Experimental conditions

(1) Flow rate: 2 mL/min,

(2) Blank electrolyte: 0.5 MH ₂ SO ₄

(3) Measurement cell structure: see Fig. 2

(4) Voltammetry scan range: 0.3 V ~ 1.2 V

(5) Scan rate: 10 mV/s

(6) Working electrode: Au, Pt, SUS

(7) Counter electrode: SUS304

(8) Reference electrode: Ag/AgCl (sat. KCl)

3) Experimental process

(1) A selection valve was adjusted to allow a blank electrolyte to flow into the microflow cell.

(2) After waiting in the OCP state for 60 seconds, the potential was scanned within the range of 0.3 V ~ 1.2 V (vs. Ag/AgCl).

(3) After completion of the scan, a 25 μM MPS, 0.5 MH ₂ SO ₄ solution was flowed into the microflow cell using a selection valve.

(4) The potential was scanned in the range of 0.3 V ~ 1.2 V (vs. Ag/AgCl).

(5) The processes of 3) to 4) were repeated for various electrolytes having different MPS concentrations.

The experimental results are shown in FIGS. 5A to 5C. 5A is a graph showing the current change by concentration of MPS when the working electrode of the electrochemical measurement cell is Au, and FIG. 5B is a graph showing the current change by concentration of MPS when the working electrode of the electrochemical measurement cell is Pt, 5C is a graph showing the current change by concentration of MPS when the working electrode of the electrochemical measurement cell is stainless steel SUS304.

As shown in FIGS. 5A to 5C, in the case of Example 1 in which the working electrode is an Au electrode, electrocatalytic activity against thiol oxidation was present, resulting in a large current density. Therefore, it can be effectively utilized as a working electrode.

On the other hand, in the case of Comparative Example 1 in which the working electrode is a Pt electrode, it is the same in that it is Au and a noble metal, but it has been confirmed that it is difficult to use it as a working electrode because the electrocatalytic activity for thiol oxidation is not high.

In addition, in the case of Comparative Example 2, in which the working electrode is an SUS electrode, it was confirmed that it was difficult to use as a working electrode because it did not act as an electrocatalyst for thiol oxidation, and a corrosion current was generated in the corresponding potential region, acting as noise.

2. Plating solution additive according to scan speed Decomposition products Measure

One) Example 2 and Comparative example 3, 4

The anode current was measured by varying the scan speed using the electrochemical measuring device of the present invention. When measuring the anode current, Example 2 set the scan speed to 10 mV/s, Comparative Example 3 set the scan speed to 50 mV/s, Comparative Example 4, except that the scan speed was set to 100 mV/s. The following experimental conditions and experimental procedures were used.

2) Experimental conditions

(1) Flow rate: 2 mL/min

(2) Blank electrolyte: 0.5 MH ₂ SO ₄

(3) Measurement cell structure: see Fig. 2

(4) Voltammetry scan range: 0.3 V ~ 1.2 V

(5) Scan rate: 10 mV/s~100 mV/s

(6) Working electrode: Au

(7) Counter electrode: SUS304

(8) Reference electrode: Ag/AgCl (sat. KCl)

3) Experimental process

(1) The selection valve was adjusted to allow the blank electrolyte to flow into the microflow cell.

(2) The potential was scanned within the range of 0.3 V ~ 1.2 V (vs. Ag/AgCl).

(3) After completion of the scan, a 25 μM MPS, 0.5 MH ₂ SO ₄ solution was flowed into the microflow cell using a selection valve.

(4) The potential was scanned within the range of 0.3 V to 1.2 V (vs. Ag/AgCl).

(5) The processes of 3) to 4) were repeated for various electrolytes having different MPS concentrations.

The experimental results are shown in FIGS. 6A to 6C. 6A is a graph showing the current change by concentration of MPS when the scan speed is 10 mV/s in the electrochemical measuring device. 6B is a graph showing the current change by concentration of MPS when the scan speed is 50 mV/s in the electrochemical measuring device. 6C is a graph showing the current change by concentration of MPS when the scan speed is 100mV/s in the electrochemical measuring device.

As shown in FIGS. 6A to 6C, when the scan speed is increased to 50 mV/s or more (Comparative Examples 3 and 4), the charging current size, which is noise, increases, and it was confirmed that the calibration curve calculation was difficult. .

3. How to calculate the calibration curve I

In order to calculate the calibration curve, the following experimental conditions and experimental procedures were used.

1) Experimental conditions

(1) Flow rate: 2 mL/min

(2) Blank electrolyte: 0.5 MH ₂ SO ₄

(3) Measurement cell structure: see Fig. 2

(4) Working electrode: Au

(5) Counter electrode: SUS304

(6) Reference electrode: Ag/AgCl (sat. KCl)

2) Experimental process

(1) The selection valve was adjusted to allow the blank electrolyte to flow into the microflow cell.

(2) 1.1 V (vs. Ag/AgCl (sat. KCl) was applied.

(3) After current such as charging current flows initially, it waits until the current stabilizes.

(4) After the 60 second time elapsed, a 25 μM MPS, 0.5 MH ₂ SO ₄ solution was flowed into the microflow cell using a selection valve.

(5) The current density was increased by the MPS inside the electrolyte.

(6) After the 60 second time elapsed, the blank solution was flowed into the microflow cell using a selection valve.

(7) The processes of 4) to 6) were repeated for various electrolytes having different MPS concentrations.

(8) The calibration curve was calculated using the peak current or the area of the peak.

The results are shown in FIG. 7. 7 is a graph showing a calibration curve according to MPS concentration by a method of measuring the concentration of an additive decomposition product contained in a plating solution according to an embodiment of the present invention. As shown in FIG. 7, a calibration curve could be calculated by the above process.

4. How to Calculate the Calibration Curve II

In order to calculate the calibration curve by another method, the following experimental conditions and experimental procedures were used.

1) Experimental conditions

(1) Flow rate: 2 mL/min

(2) Blank electrolyte: 0.5 MH ₂ SO ₄

(3) Analysis cell structure: see Fig. 2

(4) Working electrode: Au

(5) Counter electrode: SUS304

(6) Reference electrode: Ag/AgCl (sat. KCl)

2) Experimental process

(1) The selection valve was adjusted to allow the blank electrolyte to flow into the microflow cell.

(2) After waiting in the OCP state for 60 seconds, the potential was scanned within the range of 0.3 V ~ 1.2 V (vs. Ag/AgCl).

(3) After completion of the scan, a 25 μM MPS, 0.5 MH ₂ SO ₄ solution was flowed into the micro fluorine cell using a selection valve.

(4) The potential was scanned within the range of 0.3 V to 1.2 V (vs. Ag/AgCl).

(5) The processes of 3) to 4) were repeated for various electrolytes having different MPS concentrations.

(6) The calibration curve was calculated with the current density at a specific potential generated at this time.

The results are shown in FIGS. 8A and 8B. 8A is a graph showing the CV result according to the MPS concentration by the method of measuring the concentration of an additive decomposition product contained in the plating solution according to an embodiment of the present invention, and FIG. 8B is a graph showing the CV result according to the plating solution according to an embodiment of the present invention. It is a graph showing the current density according to the MPS concentration by the method of measuring the concentration of decomposition products. As shown in FIGS. 8A and 8B, a calibration curve could be calculated by the above process.

4. Analysis of deteriorated plating solution I

In order to analyze the deterioration of the plating solution in the method according to the present invention, the following experimental conditions and experimental procedures were used.

1) Experimental conditions

(1) Flow rate: 1.7 mL/min,

(2) Working electrode: Au,

(3) scan rate (LSV analysis of Fig. 9a): 10 mV/s, applied potential (Fig. 9b CA analysis): 0.9 V

(4) Blank electrolyte: 0.8 M CuSO4, 0.5 M H2SO4, 1 mM HCl

(5) Electrolyte to be analyzed

> Initial composition:

(A) 1.0 M CuSO ₄ , 0.5 MH ₂ SO ₄ , 1 mM HCl

(B) 1.0 M CuSO ₄ , 0.5 MH ₂ SO ₄ , 1 mM HCl, 500 μM SPS

(C) 1.0 M CuSO ₄ , 0.5 MH ₂ SO ₄ , 1 mM HCl, 500 μM SPS, 3 g/L PEG (MW: 1500)

> Deterioration conditions

-Three solutions were prepared in 100 mL.

-A copper electrode of 20 cm ² was immersed in the solution.

-Waited for 20 hours.

-Analysis was performed using the device according to the present invention.

The results are shown in Figs. 9A and 9B. 9A is a graph showing the results of analyzing deterioration of the plating solution through current density change for each potential by the method of measuring the concentration of an additive decomposition product contained in the plating solution according to an embodiment of the present invention after SPS or PEG is added to the plating solution. 9B is a graph showing the results of analyzing deterioration of the plating solution through current density change over time by the method of measuring the concentration of an additive decomposition product contained in the plating solution according to an embodiment of the present invention after adding SPS and PEG to the plating solution.

As shown in FIGS. 9A and 9B, Cu(I)-MPS was generated as the SPS was decomposed by the artificial copper electrode. The current density by Cu(I)-MPS was detected. The change in current density due to PEG added together was insignificant.

5. Analysis of deteriorated plating solution II

In order to analyze the deteriorated plating solution in the method according to the present invention, the following experimental conditions and experimental procedures were used.

1) Experimental conditions

(1) Flow rate: 1.7 mL/min,

(2) Working electrode: Au,

(3) applied potential (CA analysis in Fig. 10b): 0.9 V

(4) Blank electrolyte: 0.8 M CuSO4, 0.5 M H2SO4, 1 mM HCl

(5) Electrolyte to be analyzed

> Initial composition: A) 1.0 M CuSO ₄ , 0.5 MH ₂ SO ₄ , 1 mM HCl, commercial additives (combination of accelerator, moderator and leveler, containing SPS)

2) Experimental process

(1) 100 mL of the solution was prepared.

(2) ^{Into the solution, a copper electrode of 20 cm 2} was immersed.

(3) Waited for 20 hours.

(4) Analysis was carried out using the measuring device of the present invention.

(5) The concentration was measured through the prepared calibration curve.

The results are shown in FIGS. 10A and 10B. 10A is a graph showing a result of measuring a current over time according to a method for measuring a concentration of an additive decomposition product contained in a plating solution according to an embodiment of the present invention. 10B is a graph showing MPS concentration over time using a calibration curve derived by a method for measuring concentration of an additive decomposition product contained in a plating solution according to an embodiment of the present invention.

As shown in FIGS. 10A and 10B, as the plating time elapsed, the ^{concentration of Cu +} -MPS increased, and it was confirmed that the plating solution was deteriorated.

Although the present disclosure has been described in detail through specific embodiments, this is for describing the present disclosure in detail, and the present disclosure is not limited thereto, and within the technical idea of the present disclosure, by those of ordinary skill in the art. It is clear that modifications or improvements are possible. All simple modifications to changes of the present disclosure belong to the scope of the present disclosure, and the specific scope of protection of the present disclosure will be clarified by the appended claims.

100, 100' 100a, 100b, 100c: measuring cell 112: supply
114: discharge unit 120: working electrode
130: reference electrode 140: counter electrode
200, 200', 200”: supply member 210, 210', 210”: supply line
220, 220', 220”: selector valve 230, 230', 230”: pump
240, 240': wire connector 300, 300', 300a, 300b, 300c: measuring part
400, 400', 400”: control unit

Claims (17)

A selection valve capable of selectively supplying at least one of a reference plating solution and a sample plating solution;
A microflow cell including a supply unit to which the plating solution supplied through the selection valve is supplied and a discharge unit from which the supplied plating solution is discharged;
A working electrode in contact with the plating solution accommodated in the microflow cell;
A reference electrode used as a reference when determining the potential of the working electrode in contact with the plating solution accommodated in the microflow cell;
A counter electrode in contact with the plating solution accommodated in the microflow cell; And
And a detection unit capable of detecting a change in current of the working electrode,
The working electrode is made of a noble metal thin film as an anode electrode,
In order to detect the additive component of the plating solution, the anode current is measured at the working electrode,
An electrochemical measuring device for measuring the concentration of an additive decomposition product according to an increase or decrease in the anode current.
The method of claim 1,
The plating solution is supplied directly from the plating bath during plating, electrochemical measuring device.
The method of claim 1,
The plating solution is supplied after being collected from the plating bath to be analyzed, electrochemical measuring device.
The method of claim 1,
The electrochemical measuring apparatus further comprises a control unit that controls the supply of the plating solution to the microflow cell, receives a signal from the measurement unit, detects an additive component of the plating solution, and monitors the performance of the plating solution.
The method of claim 4,
The control unit controls the addition of an additive component to the plating solution.
The method of claim 1,
The electrochemical measuring apparatus further comprises a current generating unit for flowing a current having a constant current density between the working electrode and the counter electrode.
The method of claim 1,
Together with at least one of the above reference plating solutions and sample plating solutions,
Electrochemical measurement apparatus further comprising a wire connector for supplying at least one of a signal enhancer capable of enhancing the detection signal and a noise remover capable of removing noise of the detection signal to the microflow cell.
The method of claim 1,
At least one of the micro flow cells; And
Electrochemical measurement device further comprising at least one measurement unit matched to the micro flow cell.
The method of claim 1,
The working electrode is Au or a noble metal alloy thereof, or Au or a noble metal alloy thereof is coated on the surface, or Au or a noble metal alloy thereof in the form of nanoparticles is supported, an electrochemical measuring device
The method of claim 1,
The reference plating solution includes copper sulfate, sulfuric acid, and hydrochloric acid.
The method of claim 1,
The additive is at least one of an accelerator, a moderator, and a leveler, an electrochemical measuring device.
The method of claim 11,
The additive includes sodium sulfopropyl disulfide (SPS), electrochemical measuring device.
delete The method of claim 1,
The additive decomposition product is a monovalent copper ion, electrochemical measuring device.
The method of claim 1,
The additive decomposition product is 3-mercaptopropyl sulfonate (MPS), an electrochemical measuring device.
The method of claim 1,
The additive decomposition product is Cu ⁺ -MPS, an electrochemical measuring device.
The method of claim 1,
The anode current measurement is electrochemical measurement using chronoamperometry, slow scan Linear Sweep Voltammetry (LSV), or slow scan cyclic voltammetry (CV). Device.

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