JP2016114391A - Electric copper plating solution analysis device and electric copper plating solution analysis method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric copper plating solution analysis device capable of more accurately and quantitatively managing a state of an electric copper plating solution containing additives using a constant current electrolysis method.SOLUTION: An electric copper plating solution analysis device 10, which analyzes an electric copper plating solution 13 containing additives including a promoter, an inhibitor and a leveler, comprises an analyzing container 12, a working electrode 18, a reference electrode 19, a counter electrode 21, a rotation driving part 23, a current generating part 26, a potential measuring part 28, and an analysis part 31. The analysis part 31 calculates parameters representing conditions of the electric copper plating solution 13 and specifies the conditions of the electric copper plating solution 13, based on a reaction mechanism in which Cu(I) produced on a surface of the working electrode 18 substitutes the inhibitor positioned on the surface of the working electrode 18, the leveler substitutes the Cu(I) positioned on the surface of the working electrode 18, and the Cu(I) forms a complex with at least the promoter to exhibit a promotion effect.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electrolytic copper plating solution analyzer and an electrolytic copper plating solution analysis method. In particular, the electrolytic copper plating film is deposited and grown in contact holes and through holes (hereinafter referred to as “holes”) formed in high-density mounting substrates, semiconductor substrates, and semiconductor package substrates. The present invention relates to an electrolytic copper plating solution analyzing apparatus and an electrolytic copper plating solution analyzing method for analyzing an electrolytic copper plating solution used when forming a contact electrode or a through-hole electrode (via) made of a plating film.

  Conventionally, an electrolytic copper plating film is deposited and grown in holes formed in a high-density mounting substrate, a semiconductor substrate, and a semiconductor package substrate by an electrolytic plating method using an electrolytic copper plating solution. A contact electrode and a through-hole electrode (via) are formed.

In order to improve the physical properties and precipitation of the plating film, an additive having an accelerating action and a suppressing action is added to the electrolytic copper plating solution.
As a promoter having a promoting action, that is, showing a promoting effect, for example, SPS (bis (sodiumsulfopropyl) disulfide) is used.
As an additive having an inhibitory effect, that is, an inhibitory effect, the inhibitory action is strong, that is, the inhibitory effect is strong and the influence on the copper plating formation in the via is large, and the inhibitor is small, that is, the inhibitory action is small. A leveler has a small effect and improves the smoothness of copper plating.
For example, PEG (poly (ethylene glycol)) is used as the inhibitor.
For example, polyamine is used as the leveler.

  In order to stabilize the quality of the plating film, it is important to manage and adjust the amount of additive (concentration of accelerator, inhibitor, and leveler) contained in the electrolytic copper plating solution. However, since the additives are decomposed or altered as time elapses from the start of the plating reaction, management including them is necessary.

  As a management of the additive, a CVS (Cyclic Voltammetry Stripping) method is generally used. In the CVS method, the potential of the platinum rotating disk electrode is repeatedly changed at a constant rate in the plating solution, so that the deposition and dissolution of the metal plating film repeatedly occur on the surface of the electrode.

In the CVS method, since the potential scanning rate is constant, the dissolution peak area on the voltamgram is proportional to the average deposition rate, and the average deposition rate is closely related to the additive concentration in the plating solution.
The CVS method can perform a quantitative analysis of additives in a sample plating solution by creating a calibration curve of a standard plating solution.

  The conventional CVS apparatus using the CVS method has several technical problems. For example, even if the additive deteriorates due to decomposition and alteration of the additive in the electrolytic copper plating solution according to the elapsed time from the start of the plating reaction, the additive concentration including the amount of the deteriorated additive The point that will be analyzed.

As an analysis method considering such deterioration of the additive (in other words, decomposition and alteration of the additive in the electrolytic copper plating solution), the technique described in Patent Document 1 is known.
Patent Document 1 discloses that MPSA (3-mercaptopropylsulfonic acid), which is a decomposition product of SPS added as an accelerator, is analyzed using the CVS method.
Patent Document 2 discloses that a decomposition product of a leveler component is analyzed using a voltammetric method.
However, although the analysis methods disclosed in Patent Documents 1 and 2 can be implemented with a conventional CVS apparatus, there is a problem that a complicated operation is required. Specifically, it is necessary to repeat the potential scanning many times to examine the change or to measure two types of plating solutions prepared at different dilution rates.

As compared with the methods described in Patent Documents 1 and 2, the techniques described in Patent Documents 3 and 4 are known as methods for analyzing the effects of the decomposition products of additives contained in the electrolytic copper plating solution by a simpler method. ing.
Patent Document 3 discloses an analysis method for obtaining an additive amount by performing constant current electrolysis on an electrolytic copper plating solution containing a brightener and a leveler as additives to obtain a time-potential curve.
Patent Document 4 discloses an analysis method in which constant current electrolysis is performed on an electrolytic copper plating solution containing an additive, and the state of the electrolytic copper plating solution is determined from the obtained time-potential curve.
When performing the analysis methods of Patent Documents 3 and 4, a rotating electrode is used.

US Pat. No. 7,291,253 US Pat. No. 7,879,222 US Pat. No. 5,223,118 U.S. Pat. No. 8,440,555

However, the analysis method disclosed in Patent Document 3 does not perform an approach for obtaining parameters related to the electrode reaction of copper plating deposition based on the obtained results, and cannot perform quantitative analysis.
In the analysis method disclosed in Patent Document 4, it is practical that the data is approximated by a Boltzmann function and quantified. However, since the theoretical support is not sufficient, it is obtained by analyzing the analysis result. These parameters are not necessarily an accurate indication of the electrode reaction of copper plating deposition based on theory.

For this reason, with the analysis methods disclosed in Patent Documents 3 and 4, it has been difficult to grasp the parameters related to the electrode reaction of copper plating deposition as quantitative values based on the theory.
The “parameters related to the electrode reaction of copper plating deposition” as referred to herein vary depending on the balance of the effects of the accelerator, the inhibitor, and the leveler contained in the electrolytic copper plating solution. It shows the feature of the shape, and is a quantitative value for grasping the state of the plating solution (for example, the state of the accelerator, the inhibitor, and the leveler) from the shape of the graph.

  That is, using the results obtained from the analysis methods disclosed in Patent Documents 3 and 4, for example, when adjusting the additive contained in the electrolytic copper plating solution such as an accelerator, an inhibitor, and a leveler, There is a problem that the additive cannot be managed with high accuracy.

  The present invention has been made in view of the above problems, and more accurately and quantitatively manage the state of the electrolytic copper plating solution containing the additive using the constant current electrolysis method. It is an object of the present invention to provide an electrolytic copper plating solution analyzing apparatus and an electrolytic copper plating solution analyzing method capable of performing the same.

In order to solve the above-mentioned problems, the electrolytic copper plating solution analyzer according to the first aspect of the present invention uses an electrolysis method, and includes electrolytic copper containing an additive including an accelerator, an inhibitor, and a leveler. An electrolytic copper plating solution analyzer for performing analysis and analysis for specifying the condition of a plating solution, wherein an analytical container for accommodating a part of the electrolytic copper plating solution as an analytical sample, and accommodated in the analytical container The working electrode immersed in the electroplated copper plating solution for transferring electrons, and immersed in the electroplated copper plating solution housed in the analytical container, serve as a reference for determining the potential of the working electrode. A reference electrode, a counter electrode immersed in the electrolytic copper plating solution accommodated in the analysis container, a rotation drive unit for rotating the working electrode at a constant speed, and between the working electrode and the counter electrode In A current generating unit for supplying a current having a constant current density, a potential measuring unit for measuring a potential between the working electrode and the reference electrode, an elapsed time after flowing out the current, and the potential An analysis unit that analyzes the relationship, and the analysis unit analyzes the relationship between the elapsed time and the potential when Cu formed on the surface of the working electrode in the course of the deposition reaction of the copper plating film (I) As the deposition reaction of the copper plating film progresses, the seed replaces the inhibitor located on the surface of the working electrode, and the leveler proceeds the deposition reaction of the copper plating film. Accordingly, the Cu (I) species located on the surface of the working electrode are replaced, and the Cu (I) species forms a complex with at least the promoter and exhibits a promoting effect. Display the condition of the copper electroplating solution. Calculating a parameter, a configuration for specifying a condition of the copper electroplating solution by using the parameters.
In addition, the said promoter does not show a promotion effect by itself, but forms a complex with the said Cu (I) seed | species and bears stabilization of the said Cu (I) seed | species which is chemically unstable. The chemically unstable Cu (I) species forms a complex with at least the promoter and exhibits a promoting effect.
In this specification, “condition of electrolytic copper plating solution” means a factor related to the plating solution component that affects the physical properties and depositability of copper deposited on the object when the electrolytic copper plating solution is electrolyzed. I mean.

但し、ηは前記電位、Ｔは前記一定の温度、Ｉは前記電流密度、ｔは前記経過時間、ｉ_ｉは前記抑制剤が存在する際の前記銅めっき膜の析出反応時における交換電流密度、ｉ_ａは前記Ｃｕ（Ｉ）種が存在する際の前記銅めっき膜の析出反応時における交換電流密度、ｉ_ｌは前記レベラーが存在する際の前記銅めっき膜の析出反応時における交換電流密度、Ｃ_ａは溶液バルクにおける前記促進剤の濃度、Ｃ_ｌは溶液バルクにおける前記レベラーの濃度、Ｔ_ｉは銅めっき膜の表面における前記抑制剤の飽和被覆量、ｋは吸着速度の相違によって前記抑制剤が前記Ｃｕ（Ｉ）種により経時的に置換される反応速度、ｋ_２は吸着速度の相違によって前記Ｃｕ（Ｉ）種が前記レベラーにより経時的に置換される反応速度、Ｒはガス定数、αは移動係数、Ｆはファラディ定数、ｄは銅のモル密度、ｎは銅の価数である。 In the electrolytic copper plating solution analyzer, the analysis unit analyzes the relationship between the elapsed time measured by the potential measurement unit and the potential based on the following formulas (1) to (4), and It is preferable to calculate i _i , i _a , i _l , C _a ^* / T _i , and k ₂ · C _l / T _i as parameters.

Where η is the potential, T is the constant temperature, I is the current density, t is the elapsed time, i _i is the exchange current density during the deposition reaction of the copper plating film when the inhibitor is present, i _a is the exchange current density during the deposition reaction of the copper plating film in the exchange current density during the deposition reaction of the copper plating film when there is the Cu (I) species, the i _l said leveler is present, C _a is the concentration of the accelerator in the solution bulk, C _l is the concentration of the leveler in the solution bulk, T _i is the saturated coating amount of the inhibitor on the surface of the copper plating film, and k is the inhibitor depending on the difference in adsorption rate. Is the reaction rate at which the Cu (I) species is replaced with time by the Cu (I) species, k ₂ is the reaction rate at which the Cu (I) species are replaced by the leveler with time due to the difference in adsorption rate, R is the gas constant, α Is a mobile , F is Faraday constant, d is the molar density of copper, n represents a valence of copper.

The electrolytic copper plating solution analyzer of the second aspect of the present invention uses a constant current electrolysis method to specify the condition of an electrolytic copper plating solution containing an additive including an accelerator, an inhibitor, and a leveler. An electrolytic copper plating solution analyzer for performing analysis and analysis, wherein the electrolytic copper plating solution is stored in an analytical container containing a part of the electrolytic copper plating solution as an analytical sample, and immersed in the electrolytic copper plating solution contained in the analytical container A working electrode that transfers electrons, a reference electrode that is immersed in the electrolytic copper plating solution housed in the analytical container and determines the potential of the working electrode, and the analytical container The current density is constant between the counter electrode immersed in the accommodated electrolytic copper plating solution, the rotation drive unit that rotates the working electrode at a constant speed, and the working electrode and the counter electrode. Current A current generator for flowing, a potential measuring unit for measuring a potential between the working electrode and the reference electrode, and an analyzing unit for analyzing a relationship between an elapsed time after flowing out the current and the potential. And the analysis unit analyzes the relationship between the elapsed time and the potential, and the Cu (I) species generated on the surface of the working electrode in the course of the deposition reaction of the copper plating film is the copper plating. As the deposition reaction of the film proceeds, the inhibitor located on the surface of the working electrode is replaced, and as the deposition reaction of the copper plating film proceeds, the surface of the working electrode is replaced with the leveler. Based on a reaction mechanism in which the Cu (I) species forms a complex with at least an accelerator and exhibits a promoting effect, a parameter representing the condition of the electrolytic copper plating solution is substituted. Calculate and use this parameter A configuration for identifying the condition of the copper electroplating solution Te.
In addition, the said promoter does not show a promotion effect by itself, but forms a complex with the said Cu (I) seed | species and bears stabilization of the said Cu (I) seed | species which is chemically unstable. The chemically unstable Cu (I) species forms a complex with at least the promoter and exhibits a promoting effect.

但し、ηは前記電位、Ｔは前記一定の温度、Ｉは前記電流密度、ｔは前記経過時間、ｉ_ｉは前記抑制剤が存在する際の前記銅めっき膜の析出反応時における交換電流密度、ｉ_ａは前記Ｃｕ（Ｉ）種が存在する際の前記銅めっき膜の析出反応時における交換電流密度、ｉ_ｌは前記レベラーが存在する際の前記銅めっき膜の析出反応時における交換電流密度、Ｃ_ａは溶液バルクにおける前記促進剤の濃度、Ｃ_ｌは溶液バルクにおける前記レベラーの濃度、Ｔ_ｉは前記銅めっき膜の表面における前記抑制剤の飽和被覆量、ｋは吸着速度の相違によって前記抑制剤が前記Ｃｕ（Ｉ）種により経時的に置換される反応速度、ｋ_３は吸着速度の相違によって前記抑制剤が前記レベラーにより経時的に置換される反応速度、Ｒはガス定数、αは移動係数、Ｆはファラディ定数、ｄは銅のモル密度、ｎは銅の価数である。 In the electrolytic copper plating solution analyzer, the analysis unit analyzes the relationship between the elapsed time measured by the potential measurement unit and the potential based on the following formulas (5) to (8), and It is preferable to calculate i _i , i _a , i _l , C _a ^* / T _i , and k ₃ · C _l / T _i as parameters.

Where η is the potential, T is the constant temperature, I is the current density, t is the elapsed time, i _i is the exchange current density during the deposition reaction of the copper plating film when the inhibitor is present, i _a is the exchange current density during the deposition reaction of the copper plating film in the exchange current density during the deposition reaction of the copper plating film when there is the Cu (I) species, the i _l said leveler is present, C _a is the concentration of the accelerator in the solution bulk, C _l is the concentration of the leveler in the solution bulk, T _i is the saturation coating amount of the inhibitor on the surface of the copper plating film, and k is the suppression due to the difference in adsorption rate. the reaction rate, k ₃ is the reaction rate, R represents the gas constant, wherein the inhibitor by the difference in adsorption rate is over time replaced by the leveler agent is over time replaced by the Cu (I) species, alpha movement coefficient F is Faraday constant, d is the molar density of copper, n represents a valence of copper.

The electrolytic copper plating solution analysis method of the third aspect of the present invention is an electrolytic copper that specifies the condition of an electrolytic copper plating solution containing an additive including an accelerator, an inhibitor, and a leveler using a constant current electrolysis method. A plating solution analysis method, wherein a working electrode, a reference electrode, and a counter electrode are immersed in the electrolytic copper plating solution maintained at a constant temperature, and the working electrode is rotated at a constant speed; A potential measurement step of measuring a potential between the working electrode and the reference electrode by passing a current having a constant current density between the working electrode and the counter electrode; An analysis process for analyzing the relationship between the elapsed time from the current and the potential;
In the analyzing step, when analyzing the relationship between the elapsed time and the potential, Cu (I) species generated on the surface of the working electrode in the course of the deposition reaction of the copper plating film are the copper As the deposition reaction of the plating film progresses, the inhibitor located on the surface of the working electrode is replaced, and as the deposition reaction of the copper plating film progresses, the leveler Based on a reaction mechanism in which the Cu (I) species located on the surface are substituted, and the Cu (I) species forms a complex with at least the accelerator and exhibits a promoting effect, the electrolytic copper plating solution A parameter representing a condition is calculated, and the condition of the electrolytic copper plating solution is specified using the parameter.
In addition, the said promoter does not show a promotion effect by itself, but forms a complex with the said Cu (I) seed | species and bears stabilization of the said Cu (I) seed | species which is chemically unstable. The chemically unstable Cu (I) species forms a complex with at least the promoter and exhibits a promoting effect.

但し、ηは前記電位、Ｔは前記一定の温度、Ｉは前記電流密度、ｔは前記経過時間、ｉ_ｉは前記抑制剤が存在する際の前記銅めっき膜の析出反応時における交換電流密度、ｉ_ａは前記Ｃｕ（Ｉ）種が存在する際の前記銅めっき膜の析出反応時における交換電流密度、ｉ_ｌは前記レベラーが存在する際の前記銅めっき膜の析出反応時における交換電流密度、Ｃ_ａは溶液バルクにおける前記促進剤の濃度、Ｃ_ｌは溶液バルクにおける前記レベラーの濃度、Ｔ_ｉは前記銅めっき膜の表面における前記抑制剤の飽和被覆量、ｋは吸着速度の相違によって前記抑制剤が前記Ｃｕ（Ｉ）種により経時的に置換される反応速度、ｋ_２は吸着速度の相違によって前記Ｃｕ（Ｉ）種が前記レベラーにより経時的に置換される反応速度、Ｒはガス定数、αは移動係数、Ｆはファラディ定数、ｄは銅のモル密度、ｎは銅の価数である。 In the electrolytic copper plating solution analysis method, in the analysis step, the relationship between the elapsed time measured in the potential measurement step and the potential is analyzed based on the following formulas (1) to (4), It is preferable to calculate i _i , i _a , i _l , C _a ^* / T _i and k ₂ · C _l / T _i as parameters.

Where η is the potential, T is the constant temperature, I is the current density, t is the elapsed time, i _i is the exchange current density during the deposition reaction of the copper plating film when the inhibitor is present, i _a is the exchange current density during the deposition reaction of the copper plating film in the exchange current density during the deposition reaction of the copper plating film when there is the Cu (I) species, the i _l said leveler is present, C _a is the concentration of the accelerator in the solution bulk, C _l is the concentration of the leveler in the solution bulk, T _i is the saturation coating amount of the inhibitor on the surface of the copper plating film, and k is the suppression due to the difference in adsorption rate. The reaction rate at which the agent is displaced with time by the Cu (I) species, k ₂ is the reaction rate at which the Cu (I) species are replaced with time by the difference in adsorption rate, R is the gas constant, α is a shift Coefficient, F is Faraday constant, d is the molar density of copper, n represents a valence of copper.

The electrolytic copper plating solution analysis method according to the fourth aspect of the present invention uses a constant current electrolysis method to specify the condition of an electrolytic copper plating solution containing an additive including an accelerator, an inhibitor, and a leveler. A plating solution analysis method, wherein a working electrode, a reference electrode, and a counter electrode are immersed in the electrolytic copper plating solution maintained at a constant temperature, and the working electrode is rotated at a constant speed; A potential measurement step of measuring a potential between the working electrode and the reference electrode by passing a current having a constant current density between the working electrode and the counter electrode; An analysis step for analyzing the relationship between the elapsed time and the potential, and in the analysis step, when analyzing the relationship between the elapsed time and the potential, the process of the deposition reaction of the copper plating film In the working electrode The Cu (I) species generated on the surface replaces the inhibitor located on the surface of the working electrode as the precipitation reaction of the copper plating film proceeds, and the leveler is provided with the copper plating film. As the precipitation reaction proceeds, the inhibitor located on the surface of the working electrode is replaced, and the Cu (I) species forms a complex with at least the promoter and exhibits a promoting effect. Based on the above, a parameter representing the condition of the electrolytic copper plating solution is calculated, and the condition of the electrolytic copper plating solution is specified using the parameter.
In addition, the said promoter does not show a promotion effect by itself, but forms a complex with the said Cu (I) seed | species and bears stabilization of the said Cu (I) seed | species which is chemically unstable. The chemically unstable Cu (I) species forms a complex with at least the promoter and exhibits a promoting effect.

但し、ηは前記電位、Ｔは前記一定の温度、Ｉは前記電流密度、ｔは前記経過時間、ｉ_ｉは前記抑制剤が存在する際の前記銅めっき膜の析出反応時における交換電流密度、ｉ_ａは前記Ｃｕ（Ｉ）種が存在する際の前記銅めっき膜の析出反応時における交換電流密度、ｉ_ｌは前記レベラーが存在する際の前記銅めっき膜の析出反応時における交換電流密度、Ｃ_ａは溶液バルクにおける前記促進剤の濃度、Ｃ_ｌは溶液バルクにおける前記レベラーの濃度、Ｔ_ｉは前記銅めっき膜の表面における前記抑制剤の飽和被覆量、ｋは吸着速度の相違によって前記抑制剤が前記Ｃｕ（Ｉ）種により経時的に置換される反応速度、ｋ_３は吸着速度の相違によって前記抑制剤が前記レベラーにより経時的に置換される反応速度、Ｒはガス定数、αは移動係数、Ｆはファラディ定数、ｄは銅のモル密度、ｎは銅の価数である。 In the electrolytic copper plating solution analysis method, in the analysis step, the relationship between the elapsed time measured in the potential measurement step and the potential is analyzed based on the following formulas (5) to (8), It is preferable to calculate i _i , i _a , i _l , C _a ^* / T _i , and k ₃ · C _l / T _i as parameters.

Where η is the potential, T is the constant temperature, I is the current density, t is the elapsed time, i _i is the exchange current density during the deposition reaction of the copper plating film when the inhibitor is present, i _a is the exchange current density during the deposition reaction of the copper plating film in the exchange current density during the deposition reaction of the copper plating film when there is the Cu (I) species, the i _l said leveler is present, C _a is the concentration of the accelerator in the solution bulk, C _l is the concentration of the leveler in the solution bulk, T _i is the saturation coating amount of the inhibitor on the surface of the copper plating film, and k is the suppression due to the difference in adsorption rate. the reaction rate, k ₃ is the reaction rate, R represents the gas constant, wherein the inhibitor by the difference in adsorption rate is over time replaced by the leveler agent is over time replaced by the Cu (I) species, alpha movement coefficient F is Faraday constant, d is the molar density of copper, n represents a valence of copper.

  According to the electrolytic copper plating apparatus and the electrolytic copper plating solution analysis method of the present invention, the potential between the working electrode immersed in the electrolytic copper plating solution sample and the reference electrode is measured, and the relationship between the elapsed time and the potential is measured. As the copper plating film deposition reaction proceeds, the leveler replaces the Cu (I) species or the inhibitor, and the Cu (I) species forms a complex with at least the accelerator and accelerates. Based on the reaction mechanism that shows the effect, in order to calculate the parameters representing the condition of the electrolytic copper plating solution, when controlling the state of the electrolytic copper plating solution containing additives using the constant current electrolysis method, it is more accurate There is an effect that it can be managed quantitatively.

It is the schematic which shows an example of a structure of the electrolytic copper plating solution analyzer of the 1st Embodiment of this invention. It is a figure which shows an example of the front-end | tip part of the working electrode used for the electrolytic copper plating solution analyzer of the 1st Embodiment of this invention. It is a graph which shows an example of the measurement data in Example 1, 2 using the electrolytic copper plating apparatus of the 1st Embodiment of this invention, and an analysis result. It is a graph which shows an example of the measurement data in Example 3, 4 using the electrolytic copper plating apparatus of the 2nd Embodiment of this invention, and an analysis result. It is a graph which shows an example of the measurement data and analysis result in the reference examples 1 and 2 using the electrolytic copper plating apparatus of a reference example.

Embodiments of the present invention will be described below with reference to the accompanying drawings. In all the drawings, even if the embodiments are different, the same or corresponding members are denoted by the same reference numerals, and common description is omitted.
The drawings used in the following description are for explaining the configuration of the embodiment of the present invention, and the sizes, thicknesses and dimensions of the respective parts shown in the drawings are different from the dimensional relationship of an actual electrolytic copper plating solution analyzer. There is a case.

[First Embodiment]
The electrolytic copper plating solution analyzer of the first embodiment of the present invention will be described.
FIG. 1 is a schematic diagram showing an example of the configuration of the electrolytic copper plating solution analyzer according to the first embodiment of the present invention. FIG. 2 is a diagram illustrating an example of a tip portion of a working electrode used in the electrolytic copper plating solution analyzer according to the first embodiment of the present invention.

  As shown in FIG. 1, the electrolytic copper plating solution analyzer 10 of this embodiment includes a stand 11, an analysis container 12, a temperature holding unit 15, an electrode support unit 16, a working electrode 18, and a reference electrode 19. A counter electrode 21, a rotation drive unit 23, a current generation unit 26, a potential measurement unit 28, a controller 25, and an analysis unit 31.

The stand 11 includes a stage unit 11A on which the analysis container 12 and the temperature holding unit 15 are mounted.
The analysis container 12 is a container for accommodating a part of the electrolytic copper plating solution 13 to be analyzed as an analysis sample. The analysis container 12 is disposed on the stage portion 11 </ b> A of the stand 11.
Examples of the electrolytic copper plating solution 13 to be analyzed include an electrolytic copper plating solution 13 used in an appropriate plating apparatus (not shown). However, the object of analysis is not limited to the used electrolytic copper plating solution 13. For example, the unused electrolytic copper plating solution 13 may be analyzed for the purpose of obtaining comparison data when conditions are good. Is possible.

Here, the electrolytic copper plating solution 13 will be described.
The electrolytic copper plating solution 13 can employ a configuration including at least Cu (II) ions and an additive.
In the additive, an accelerator, an inhibitor, and a component exhibiting the action of a leveler are mixed. These components are often added as separate compounds as accelerators, inhibitors, and levelers, but compounds that exhibit multiple actions with multiple functional groups may be used.
As the accelerator, for example, a sulfur-containing compound such as SPS [bis (sodiumsulfopropyl) disulfide] can be used.
As the inhibitor, for example, a water-soluble polymer such as polyethylene oxide or polypropylene oxide, PEG [poly (ethylene glycol)], or the like can be used.
As the leveler, for example, an organic compound such as polyamine, polyacrylamine, poly (N-methyldiallylamine), poly (N-vinylpyrrolidone), poly (N-vinyl-N′-methylimidazolium chloride) is used. it can.
The additive contained in the electrolytic copper plating solution 13 is supplied from many suppliers as a single substance or in various combinations.

The electrolytic copper plating solution 13 may contain an anion (for example, sulfate ion), an acid (for example, sulfuric acid), and a chlorine ion, which are counter ions of Cu (II) ions.
The amount of Cu (II) ions contained in the electrolytic copper plating solution 13 can be set, for example, in the range of 2 g / L to 70 g / L. The amount of sulfuric acid can be set, for example, within a range of 10 g / L to 200 g / L. The amount of chlorine is, for example, within a range of 1 g / L to 150 mg / L.
Each optimum amount may be determined by performing performance evaluation of the electrolytic copper plating solution 13 or the like. The concentration of the additive component is also the same.

The temperature holding unit 15 is placed on the stage unit 11 </ b> A so as to surround the outer peripheral side surface of the analysis container 12. The temperature holding unit 15 is for holding the temperature of the electrolytic copper plating solution 13 accommodated in the analysis container 12 at a constant temperature.
The temperature of the electrolytic copper plating solution 13 is preferably selected from, for example, 20 ° C to 35 ° C. The temperature fluctuation that can be regarded as constant is ± 1K.
For example, a constant temperature water tank can be used as the temperature holding unit 15.
By having such a temperature holding unit 15, the accuracy of analysis can be stabilized.
In FIG. 1, as an example, the temperature holding unit 15 surrounding the outer peripheral side surface of the analysis container 12 is illustrated. It is also possible to have a configuration covering.

The electrode support portion 16 is fixed to the upper end portion of the stand 11. The electrode support portion 16 is arranged so as to face the liquid surface of the electrolytic copper plating solution 13 accommodated in the analysis container 12.
The electrode support part 16 is a member for supporting the rear ends of a working electrode 18, a reference electrode 19, and a counter electrode 21, which will be described later.

In the present embodiment, the potential measured using the working electrode 18, the reference electrode 19, and the counter electrode 21 changes depending on the positional relationship among the working electrode 18, the reference electrode 19, and the counter electrode 21.
For this reason, it is preferable that the potential measurement is performed in a state where the positions of the working electrode 18, the reference electrode 19, and the counter electrode 21 are always fixed. For example, a configuration in which the positional relationship among the working electrode 18, the reference electrode 19, and the counter electrode 21 needs to be adjusted every time the electrolytic copper plating solution 13 (analysis sample) is replaced is not preferable.
Therefore, in order to measure potential data with better reproducibility, it is preferable to adopt a configuration in which the positional relationship among the working electrode 18, the reference electrode 19, and the counter electrode 21 can be fixed as the electrode support portion 16.

The working electrode 18 is supported by the electrode support 16 via a rotation driving unit 23 described later so that the tip of the working electrode 18 is immersed in the electrolytic copper plating solution 13.
The working electrode 18 is an electrode that exchanges electrons with the chemical species in the electrolytic copper plating solution 13.

As shown in FIG. 2, the working electrode 18 includes an exterior member 35, a working electrode body 37, and a conductive wire 39.
The exterior member 35 is an insulating member having a cylindrical shape.
A flat distal end surface 35 a is formed at the distal end of the exterior member 35. A working electrode main body accommodating portion 35A including a concave portion for accommodating the working electrode main body 37 is formed at the center of the distal end surface 35a.

The working electrode body 37 is made of a conductive material, and is accommodated in the working electrode body housing portion 35A.
The working electrode body 37 has a surface 37 a exposed from the exterior member 35. Thereby, when the working electrode body 37 is immersed in the electrolytic copper plating solution 13, the working electrode body 37 can contact the electrolytic copper plating solution 13 on the surface 37 a.
As the shape of the working electrode body 37, for example, a disk-shaped electrode is preferable, but is not limited thereto.
The surface area of the surface 37a, for example, is preferably set in the range of 0.01 cm ² 1 cm ^2.
As a material of the working electrode body 37, for example, an electrically stable noble metal material such as platinum can be used.
In addition, the shape of the exterior member 35, the working electrode body 37, and the surface 37a is not limited to the above shape or the illustrated shape.

  One end of the conducting wire 39 is connected to the working electrode main body 37 and is electrically connected to the current generator 26.

As shown in FIG. 1, the reference electrode 19 is supported by the electrode support 16 so that the tip of the reference electrode 19 is immersed in the electrolytic copper plating solution 13.
The reference electrode 19 is an electrode serving as a reference when determining the potential of the working electrode 18.
As a material of the reference electrode 19, for example, saturated calomel (Hg / Hg ₂ Cl ₂ ), silver / silver chloride (Ag / AgCl), or the like can be used.

The counter electrode 21 is supported by the electrode support 16 so that the tip of the counter electrode 21 is immersed in the electrolytic copper plating solution 13.
The counter electrode 21 is an electrode for causing a current to flow through the electrolytic copper plating solution 13 between the working electrode 18 and causing a reaction at the interface between the electrode and the electrolytic copper plating solution 13.
As the counter electrode 21, for example, a copper electrode that is a soluble electrode or a platinum-coated titanium electrode that is an insoluble electrode can be used.
The surface area of the counter electrode 21 is such that the surface area of the working electrode body 37 of the working electrode 18 can be immersed in the electrolytic copper plating solution 13 so that the total current is not limited by the reaction on this electrode. The surface area is preferably greater than or equal to the surface area. Specifically, the surface area that can be immersed in the electrolytic copper plating solution 13 in the counter electrode 21 is preferably, for example, 1 to 50 times the surface 37 a of the working electrode body 37.
The counter electrode 21 may be called a counter electrode or an auxiliary electrode.

The rotation drive unit 23 is accommodated in the electrode support unit 16 and connected to the rear end of the working electrode 18.
The rotation drive unit 23 is a device part that rotates the working electrode 18 at a constant speed.
The number of rotations (rotation speed) of the working electrode 18 by the rotation drive unit 23 can be set, for example, within a range of 10 rpm to 8000 rpm.
When the rotation speed of the working electrode 18 is changed by the rotation driving unit 23, the diffusion state of the additive in the electrolytic copper plating solution 13 changes. Therefore, depending on the difference in concentration of each component of the additive, the ease of appearance of a difference in potential measurement data, which will be described later, also changes depending on the rotation speed.
Therefore, by conducting a preliminary study such as by changing the number of revolutions, the number of revolutions that are relatively easy to see changes in the measurement data can be found in advance depending on the composition of each component of the additive. It is preferable to measure the potential described later.
The number of rotations of the working electrode 18 by the rotation driving unit 23 is preferably 10 rpm or more in which the effect of rotation appears. On the other hand, if the rotation speed of the working electrode 18 by the rotation drive unit 23 is greater than 8000 rpm, it is not preferable because it is difficult to control the rotation speed mechanically.

The current generator 26 is electrically connected to the working electrode 18 and the counter electrode 21.
The current generator 26 is a device part for allowing a current having a constant current density I in the working electrode 18 to flow between the working electrode 18 and the counter electrode 21.
As the current generator 26, for example, a DC current that is 10 A or less and 10 V or less can be controlled within a range of ± 10 mV or less with respect to a set voltage and within a range of ± 10 mA or less with respect to the set current. Is preferred.
As the current generator 26, for example, a DC stabilized power supply can be used.

The current density at the working electrode 18 I is ^preferably in the range of ^{0.1A / dm 2 ~20A / dm 2} , in the range of 0.5A ^/ dm ² ~5A ^/ dm 2 is more preferable.
If the current density I is smaller than 0.1 A / dm ² , the difference in the measurement result of the potential hardly appears. If the current density I is greater than 5 A / dm ² , the potential is difficult to stabilize.

The potential measurement unit 28 is communicably connected to the working electrode 18, the reference electrode 19, and an analysis unit 31 described later.
The potential measuring unit 28 measures the potential η between the working electrode 18 and the reference electrode 19 in a state where a current having a constant current density I flows between the working electrode 18 and the counter electrode 21. It is. Data relating to the potential η measured by the potential measuring unit 28 is transmitted to the analyzing unit 31.
As the potential measuring unit 28, for example, a potentiometer, a voltmeter, a multimeter, or the like that can be measured with a potential accuracy of about ± 10 mV during potential measurement can be used.
Before starting the measurement of the potential η, the working electrode 18 is rotated at a constant rotational speed.

The time for measuring the potential η (hereinafter referred to as “measurement time t _m ”) is preferably as short as possible within the range where the value of the potential η is stable.
If the measurement time t _m is too short, for example, 10 seconds or less, the copper plating film deposited on the surface 37a of the working electrode 18 is not stable, and it is difficult to obtain reliable parameters. .
The measurement time t _m is preferably set as appropriate within a range of 1 minute to 40 minutes, for example.

The controller 25 is communicably connected to the rotation drive unit 23, the current generation unit 26, and the potential measurement unit 28.
The controller 25 is for controlling the rotation drive unit 23, the current generation unit 26, and the potential measurement unit 28.
As shown in FIG. 1, the controller 25, the current generator 26, and the potential measurement unit 28 may be separated, or a plurality of units may be integrated.
The controller 25 may be configured integrally with an analysis unit 31 described later.

The analysis unit 31 includes an analysis unit main body 42, a display 43 that displays the analysis result, a keyboard 44, and a mouse (not shown). As a device configuration of the analysis unit 31, a computer including a CPU, a memory, an input / output interface, an external storage device, and the like, for example, a personal computer can be used.
The analysis unit main body 42 is communicably connected to the controller 25, the current generation unit 26, the potential measurement unit 28, the display 43, the keyboard 44, and a mouse (not shown).
Moreover, the analysis part main body 42 may be connected so that communication with the rotation drive part 23 is possible so that the rotational speed of the working electrode 18 can be controlled.

The analysis unit main body 42 includes a program for controlling the controller 25, the current generation unit 26, the potential measurement unit 28, and the display 43, a program for performing the electrolytic copper plating solution analysis method of the present embodiment, which will be described later, and the like. Stored.
The analysis unit main body 42 can perform various controls and data analysis by executing these programs.
For example, as an example of data analysis performed by the analysis unit main body 42, a parameter representing the condition of the electrolytic copper plating solution 13 is calculated based on the data of the potential η measured by the potential measurement unit 28, and this parameter is used. Data analysis for specifying the condition of the electrolytic copper plating solution 13 can be given.
The analysis unit main body 42 preferably has a function of controlling each series of measurement and analysis by integrating each function related to the analysis from the measurement of the potential η.
When the analysis unit main body 42 is connected to the rotation drive unit 23 so as to be communicable, a program for controlling the rotation drive unit 23 may be stored in the analysis unit main body 42.
Details of control and data analysis performed by the analysis unit 31 will be described together with an explanation of the operation of the electrolytic copper plating solution analyzer 10.

Next, operation | movement of the electrolytic copper plating solution analyzer 10 of this embodiment is demonstrated centering on the electrolytic copper plating solution analysis method of this embodiment.
In order to specify the condition of the electrolytic copper plating solution 13 used in an appropriate plating apparatus (not shown) by the electrolytic copper plating solution analyzer 10, the preparation process, potential in the electrolytic copper plating solution analysis method of the present embodiment The measurement process and the analysis process are performed in this order.

The preparation step is a step in which the working electrode 18, the reference electrode 19 and the counter electrode 21 are immersed in the electrolytic copper plating solution 13 maintained at a constant temperature, and the working electrode 18 is rotated at a constant speed.
Specifically, the electrolytic copper plating solution 13 is accommodated in the analysis container 12 and held in the temperature holding unit 15. Then, the working electrode 18, the reference electrode 19, and the counter electrode 21 are immersed in the electrolytic copper plating solution 13.
When the temperature of the electrolytic copper plating solution 13 reaches a constant temperature T, the controller 25 is operated to rotate the rotational drive unit 23 at a constant rotational speed that is predetermined for analysis. Thereby, the working electrode 18 supported by the rotation driving unit 23 starts to rotate at a constant rotational speed.
In addition, when the analysis part main body 42 of the analysis part 31 can control the rotation drive part 23, this operation can also be performed through the analysis part main body 42.
This completes the preparation process.

Next, a potential measurement step is performed. This step is a step of measuring the potential η between the working electrode 18 and the reference electrode 19 by passing a current having a constant current density I between the working electrode 18 and the counter electrode 21.
In this step, by operating the keyboard 44 or mouse, the analysis unit main body 42 activates a data analysis program and starts potential measurement.
As a result, a control signal is sent from the analysis unit main body 42 to the current generation unit 26 and the potential measurement unit 28, the current generation unit 26 and the potential measurement unit 28 operate, and potential measurement is started. Alternatively, the control signal may be sent from the analysis unit main body 42 to the current generation unit 26 and the potential measurement unit 28 via the controller 25, and the current generation unit 26 and the potential measurement unit 28 may operate to start the potential measurement. .
That is, a current having a constant current density I flows between the working electrode 18 and the counter electrode 21 by the current generator 26 and the potential η is measured by the potential measuring unit 28.
The potential η is measured at an appropriate measurement interval during a predetermined measurement time t _m , and measurement data of the potential η at an elapsed time t after the current starts flowing is acquired.
The acquired potential η for each elapsed time t is sent to the analysis unit 31.
Upon receiving the measurement data of the potential η, the analysis unit 31 displays a measurement data graph on the display 43.
This completes the potential measurement process.

Next, an analysis process is performed. This step is a step of analyzing the relationship between the elapsed time t and the potential η after the current is flown between the working electrode 18 and the counter electrode 21.
This process is automatically started by the analysis unit 31 when the measurement time t _m elapses and all measurement data measured by the potential measurement unit 28 is sent to the analysis unit 31 during the measurement time t _m. The
The time change of the potential η represents the progress of the precipitation reaction of the copper plating film in the electrolytic copper plating solution 13, and the temporal change in the effect of promoting and suppressing the precipitation reaction due to the additive in the electrolytic copper plating solution 13. It is reflected.
Therefore, the condition of the electrolytic copper plating solution 13 can be specified if, for example, a factor representing the precipitation reaction promotion effect, a factor representing the suppression effect, and the like can be obtained as quantitative parameters from the time change of the potential η. become.
In the electrolytic copper plating solution analyzer 10, each component of the plating solution (accelerator, inhibitor, parameter) (i _i , i _a , i _l , C _a ^* / T _i , k ₂ · C _l / T _i ) And the leveler) are quantified, and the state of the plating solution can be specified.
In order to calculate a parameter representing the condition of the electrolytic copper plating solution 13 from the time change of the electric potential η, the present inventor is based on the reaction mechanism of the precipitation reaction, a factor representing the precipitation reaction promoting effect, a factor representing the suppression effect, etc. The inventors have derived a theoretical relational expression that includes a parameter representing the constant as a constant coefficient, and applied the relational expression to the time change of the potential η to identify the parameter, and have reached the present invention.
Therefore, before describing the operation of the analysis unit 31, a reaction mechanism and relational expressions used in the analysis process of the present embodiment executed by the analysis unit 31 will be described.

First, the reaction mechanism of copper plating film deposition considered by the present inventor will be described.
The copper electroplating solution 13 includes Cu (II) ions, an additive in which components that act as inhibitors, accelerators and levelers are mixed, and an anion (for example, sulfuric acid) which is a counter ion of Cu (II) ions. Ion), an acid (for example, sulfuric acid), and a chlorine ion.
However, the promoter alone does not show a promoting effect, and forms a complex with the Cu (I) species generated on the surface 37a of the working electrode body 37 shown in FIG. 2 to form a chemically unstable Cu (I) species. Responsible for stabilization. A chemically unstable Cu (I) species forms a complex with at least an accelerator and exhibits a promoting effect. For example, a chemically unstable Cu (I) species forms a complex with a promoter, a decomposition product of the promoter, chlorine, and the like, and exhibits a promoting effect.

Immediately after the copper plating film starts to deposit on the cathode (cathode electrode) by electrolysis, the additive, the inhibitor, the accelerator, and the leveler are adsorbed to cover the surface of the copper plating film.
The copper plating film is deposited between the additive thin film layer adsorbed on the surface of the cathode and the cathode and is taken in as a metal film. Immediately after the copper plating film starts to deposit, the order in which the additive adsorption effect is strong is the order of the inhibitor, the accelerator, and the leveler.

The reduction reaction of Cu (II) ions to metallic copper (in other words, zero-valent Cu) passes through Cu (I) ions as an intermediate. Most Cu (I) ions are reduced to metallic copper, but some Cu (I) ions combine with chlorine or promoter components as by-products to form and stabilize Cu (I) species, Some remain on the surface of the deposited copper metal.
For this reason, as the precipitation reaction of the copper plating film proceeds, the surface concentration of the Cu (I) species on the surface of the copper plating film increases. As this Cu (I) seed | species, for example, it produces | generates from the Cu (I) ion produced by reaction with the promoter component and the electrode in the electrolytic copper plating solution 13, for example, Cu (I) complex etc. correspond, Since this has a catalytic action of electrode reaction, an accelerating effect appears.

Further, as the deposition reaction of the copper plating film proceeds, the concentration of Cu (I) species (for example, Cu (I) complex) in the vicinity of the surface of the cathode increases and immediately after the copper plating film starts to deposit, this Cu (I) Species replace the inhibitor adsorbed on the cathode. Further, in the process of depositing the copper plating film, the leveler replaces the Cu (I) species adsorbed on the cathode.
In the deposition of the copper plating film, an inhibitor component, a leveler component, and an accelerator component that is not complexed with Cu (I) ions are supplied from the electrolytic copper plating solution 13 to the cathode surface together with Cu (II) ions. On the other hand, desorption of the inhibitor component, leveler component, and accelerator component that existed on the cathode surface also occurs. These generations, adsorptions, and desorptions bring the balance of additive components on the cathode surface toward equilibrium.

According to “Reference-2” described later, in the reaction mechanism in which the Cu (I) species complex on the cathode surface exhibits a promoting effect, the Cu (I) species are produced on the cathode surface as described above, and In addition to those adhered to the cathode surface, there are those produced on the cathode surface and then desorbed from the cathode, and those produced with an electrolytic copper plating solution.
It is conceivable that such Cu (I) species not present on the cathode surface exhibit an accelerating effect different from that of the Cu (I) species on the cathode surface. When this Cu (I) species not present on the cathode surface moves to the cathode surface by diffusion, it participates in the copper plating deposition reaction of the cathode and exhibits an accelerating effect.

When the reaction mechanism of the precipitation reaction described above is applied to the reaction in the analytical container 12 of the electrolytic copper plating solution analyzer 10, the working electrode 18 which is the cathode in the process of the copper precipitation reaction during the measurement of the potential η. The Cu (I) species generated on the surface 37a replaces the inhibitor on the surface 37a as the precipitation reaction proceeds, and the leveler replaces the Cu (I) species. The reaction mechanism is to form a complex with at least an accelerator and exhibit a promoting effect. For example, Cu (I) species forms a complex with a promoter, a decomposition product of the promoter, chlorine, and the like, and exhibits a promoting effect.
In the present embodiment, the following formulas (1) to (4) are adopted as the relational expressions representing the time change of the potential η in such a reaction mechanism.

Here, exp represents an exponential function, and ln represents a natural logarithmic function. Further, eta potential, T is the temperature of the copper electroplating solution 13, I is the current density, t is the elapsed time, i _i is the exchange current density during the deposition reaction of the copper plating film due to presence of the inhibitor, i _a in exchange current density, i _l exchange current density during the deposition reaction of the copper plating film due to presence of levelers, C _a is the solution bulk during the deposition reaction of the copper plating film when there is Cu (I) species the concentration of the promoter, C _l is the concentration of the leveler in the solution bulk, T _i is the saturation coverage of inhibitors on the surface of the copper plating film, k is the time the inhibitor is Cu (I) species by the difference in adsorption rate The reaction rate to be substituted, k ₂ is the reaction rate at which Cu (I) species are displaced by the leveler over time due to the difference in adsorption rate, R is the gas constant, α is the transfer coefficient, F is the Faraday constant, and d is the copper Molar density, n is the valence of copper A.
The exchange current densities i _i , i _a and i _l are exchange current densities on the surface 37 a of the working electrode 18.

Next, the background of obtaining the above (1) to (4) will be described.
The formation of wiring on a semiconductor substrate using an electrolytic copper plating method is already a widely used technique, and many studies on the action of inhibitors and accelerators on the plating surface have already been reported.
For example, “Mechanistic Analysis of the Bottom-Up Fill in Copper Interconnect Metallization (Rohan Akolkarz and Uziel Landau)” described in D351-D359 of Journal of The Electrochemical Society (2009), 156 (9) (hereinafter referred to as this document) In order to simulate the embedding property by bottom-up deposition of the copper plating film with respect to the via hole and the trench formed in the semiconductor substrate, the diffusion of the additive composed of the inhibitor and the accelerator, and its The result of analyzing the adsorption behavior is described.
For example, “Surface Technology” Vol. 12, 2008, P857-P862, “Experimental Copper Plating Monitoring by Electrochemical Technique” (hereinafter referred to as “Reference 2”), in an electrolytic copper plating solution, an accelerator and Cu (I It is described that the Cu (I) complex which is a reaction product with) exhibits an accelerating effect.

In the above reference, it is considered that the inhibitor has a slower diffusion and faster adsorption than the accelerator, and the accelerator has a faster diffusion and slower adsorption.
Moreover, in the said reference document, the speed | rate of precipitation of a local copper plating film | membrane is simulated from the adsorption | suction behavior of the inhibitor component and promoter component in the inner surface and outer surface of a via hole.
At that time, the rate of deposition of the copper plating film on the inner and outer surfaces of the via hole is determined as the total current is distributed according to the adsorption behavior of the additive component on the electrode surface, that is, the coverage of the inhibitor and the accelerator. ing.
Furthermore, in the reference literature, since the speed of diffusion and adsorption described above differs between the inhibitor and the accelerator, it is considered that the accelerator replaces the inhibitor previously adsorbed with the passage of time. This interprets the mechanism in which the accelerator is preferentially adsorbed on the bottom surface of the via hole and bottom-up precipitation occurs.

The concept of these references regarding the accelerator and the inhibitor can be similarly applied to the phenomenon occurring on the surface 37a of the rotating working electrode 18 in the present embodiment.
However, in this embodiment, it is not necessary to consider the area | region which is not covered by any of the inhibitor and promoter which are assumed by the said reference.
In this embodiment, since the rotating working electrode 18 is used, it is considered that the additive component contained in the electrolytic copper plating solution 13 is sufficiently supplied to the surface of the electrode. There is no need.

The current I _i in the region occupied by the suppressor in the surface 37a is expressed by the following formula (9) from the Tafel equation which is the basic formula of electrochemistry, and the current I _i in the region occupied by the promoter in the surface 37a is current _{I a} is represented by the following formula (10), the current _{I l} of the area occupied by the leveler of the surface 37a is expressed by the following equation (11).

Here, transfer coefficient alpha _i are inhibitors, alpha _a movement coefficient of promoter, alpha _l is transfer coefficient leveler, theta _i is the coverage of the inhibitor on the surface 37a, theta _a the promoter at the surface 37a The coverage, θ _l, is the leveler coverage on the surface 37a.

Since the current density I on the surface 37a is the sum of the current densities I _i , I _a , and I _l , the current density I can be expressed as the following formula (12).

The values of the movement coefficients α _i , α _a and α _l are substantially equal. Since such a copper plating reaction is a reversible reaction, the transfer coefficients α _i , α _a , and α _l are all considered to be approximately 0.5. For this reason, it is possible to replace the movement coefficients α _i , α _a , and α _l with the movement coefficient α.
Therefore, when the movement coefficient α is used, the following expressions (13) and (14) are obtained from the above expression (12).

Regarding the changes in the coverages θ _i , θ _a , and θ _l , the inhibitor is adsorbed on the surface 37a at the initial stage of deposition of the copper plating film on the surface 37a based on the reaction mechanism of the present embodiment as described above. However, it is considered that the adsorbed inhibitor is replaced by the accelerator with time, and the accelerator adsorbed on the surface 37a is replaced by the leveler.
Since the accelerator coverage θ _a is replaced with the leveler coverage θ _l , the accelerator coverage with the amount replaced by the leveler added (in other words, the sum of the coverage θ _a and the coverage θ _l ). Is the coverage θ _a ′.
The coverages θ _i and θ _l can be expressed by the following equations (15) and (16) based on the diffusion equation, according to the model of the above-mentioned reference.

Since the sum of the coverage ratio θ _i and the coverage ratio θ _a ′ is “1”, the coverage ratio θ _a ′ can be expressed by the following formula (17).

Further, since the coverage θ _a ^′ is the sum of the coverage θ _a and the coverage θ _l , the coverage θ _a can be expressed by the following formula (18).

  When the above formulas (15) to (18) are substituted into the above formula (14), the following formula (19) is obtained.

In the above formula (19), when an inhibitor, an accelerator, and a leveler are included, the inhibitor adsorbed on the surface 37a is replaced by the accelerator over time due to the difference in adsorption speed of each component, and adsorbed on the surface 37a. It is a relational expression showing the time change of electric potential (eta) derived | led-out based on the model that the promoted accelerator is substituted with time by the leveler.
However, it was found that there is a large difference between the potential obtained by actual measurement and the potential η calculated by the above equation (19).
Therefore, as a result of various studies, the present inventor has found that it is better to assume another reaction mechanism than to think that the accelerator is brought from the electrolytic copper plating solution 13 by diffusion.
That is, in the course of the deposition reaction of the copper plating film, the Cu (I) species generated on the surface 37a of the working electrode 18 becomes an inhibitor of the surface 37a of the working electrode 18 as the deposition reaction of the copper plating film proceeds. Assuming a reaction mechanism in which the leveler replaces the Cu (I) species on the surface 37a of the working electrode 18, and the Cu (I) species itself forms a complex with at least an accelerator and exhibits a promoting effect. It was found that the measurement results can be explained better.
The reaction that Cu (I) species generated on the cathode surface by the copper deposition reaction replaces the inhibitor on the cathode surface as the deposition reaction progresses, and itself forms a complex with at least the promoter to show a promoting effect. Considering the mechanism, k in the above equation (19) is replaced with a factor including the current density. That is, it was considered that the reacting Cu (I) species increased in proportion to the current density, that is, the reaction rate increased.
Therefore, in the above formula (1), the reaction rate k in the above formula (19) is replaced with a factor including the current density I as shown in the following formula (20).

In the current density I, Cu (I) produced in the process of copper reduction reaction acts as _a solution bulk accelerator with _a concentration Ca, and the newly produced Cu (I) species was present on the electrode surface. Replace the agent layer. However, this Cu (I) species is not a single species, and the promoting effect exhibited by each species is different. However, since it is practically impossible to determine the concentration of each Cu (I) species, here, a factor C _a ^* that represents the promotion effect of the Cu (I) species as a whole including the concentration C _a is defined. Used as a parameter obtained from the measurement. This is also considered to be obtained by multiplying C _a by a coefficient representing the degree of promotion.
The coefficient B is a coefficient introduced for matching the dimensions, and is expressed by the above equation (3).
Since the Cu (I) species is composed of a plurality of compositions having different promoting effects, it is practically impossible to determine the concentration of each composition.
However, the promotion effect factor C _a ^* is a factor representing the promotion effect of the Cu (I) species as a whole in proportion to the concentration C _a of the promoter in the solution bulk. That is, it is a value indicating the total acceleration effect in the electrolytic copper plating solution 13 in consideration of the decomposition and alteration of the additive.

Next, operation | movement of the analysis part 31 using the said Formula (1) in an analysis process is demonstrated.
In the present embodiment, the analysis unit main body 42 stores an analysis program for calculating the parameters in the above equation (1). The analysis program calculates the parameters by fitting the measurement data of the potential η sent from the potential measuring unit 28 according to the above equation (1).
The analysis method used for the analysis program is not particularly limited. For example, it is possible to employ analysis methods such as curve fitting using the least square method, the gradient of the measured potential, and the average value of the measured potential.
In the present embodiment, curve fitting using a least square method is employed as an example.
Further, constants used for analysis, for example, constants necessary for the calculations of the above formulas (2) and (3) are stored in the analysis unit main body 42 in advance.

When the analysis unit body 42 executes the analysis _{program, p 1, p 2, p} 3 represented by the following formula as a parameter _{(21) ~ (25),} p 4, p 5 ( hereinafter, "parameter _p 1 ~p ₅ Is sometimes abbreviated as “.”).
In the present embodiment, since the least square method is used, the analysis unit main body 42 sets an appropriate initial value for the parameters p _{1 to} p ₅ and executes the analysis program, so that the deviation from the measurement data is the least square method. The parameters p _{1 to} p ₅ are changed repeatedly until convergence so as to be minimized. In the present embodiment, the residual sum of squares S is also calculated.

The calculated parameters p _{1 to} p ₅ , the function η (t) determined by curve fitting, and the residual square sum S are displayed on the display 43 together with the graph of the measurement data.

These parameters p _{1 to} p ₅ are parameters that allow the condition of the electrolytic copper plating solution 13, in other words, the state of the inhibitor, the Cu (I) species, and the leveler to be known.
For this reason, the combination of the parameters p _{1 to} p ₅ is a numerical value group that specifies the condition of the electrolytic copper plating solution 13.

The parameters p ₁ , p ₂ and p ₃ are the exchange current densities i _i , i _a and i _l , respectively. Inhibitors, Cu (I) species, and the respective effects of the leveler is large, the magnitude of the exchange current density _{i i, i a, i l} is changed.
Since the parameter p ₄ is C _a ^* / T _i , the parameter p ₄ is a parameter representing the ratio between the promotion effect and the suppression effect.
If the parameter p ₄ is increased it can be seen that the promoting effect is relatively increased with respect to suppressing effect. Further, the parameter p ₄ is reduced, it can be seen that the inhibitory effect is relatively increased with respect to promoting effect.
Parameter p ₅ are the _{k 2 · C l / T i} , the substitution reaction rate of the accelerator and leveler, which is a parameter representing a smoothing effect, a suppressive effect, the relationship.
If the parameter p ₅ increases, the smoothing effect increases. Further, when the parameter p ₅ becomes small, smooth effect is reduced. When the parameter p ₅ deviates from a certain range, each effect becomes excessive and a problem occurs.
For example, in the via filling plating, a phenomenon such as a decrease in the filling degree of the copper plating film in the via hole appears.

The condition of the electrolytic copper plating solution 13 specified by these parameters p _{1 to} p ₅ can be determined as to whether the condition is good or not by setting determination conditions in advance.
The determination condition may be set based on the correspondence between the value of each parameter and the evaluation result, for example, by performing a performance evaluation experiment as a plating solution using a sample of the electrolytic copper plating solution 13 in which each parameter is shaken. it can.
As the determination condition, for example, it is possible to obtain an allowable range of each parameter for which the performance is good.
In addition, the allowable range can be determined not by the allowable range for each parameter but by a numerical value of an evaluation formula obtained by combining or weighting a plurality of parameters.
Such a determination may be made by the measurer by looking at each parameter displayed on the display 43, but the determination condition is stored in the analysis unit main body 42, and the analysis unit main body 42 determines the value of each parameter. The determination may be made automatically by comparing the conditions. When the analysis unit main body 42 performs the determination, the determination result is also displayed on the display 43 together with the numerical value of each parameter.

In the present embodiment, since the residual square sum S is also calculated, the accuracy of curve fitting can be determined based on the magnitude of the residual square sum S. For example, when the residual sum of squares S is too large, for example, the influence of measurement error such as variation in measured data of the potential η may be considered. For this reason, it is possible to take measures such as re-measurement of the electric potential according to the magnitude of the residual sum of squares S, or re-analysis by removing obvious abnormal data.
This completes the analysis process.

According to the electrolytic copper plating solution analyzer 10 of the present embodiment, the potential η between the working electrode 18 and the reference electrode 19 immersed in the analysis sample of the electrolytic copper plating solution 13 is measured, and the elapsed time t and the potential η are measured. Can be calculated, and a parameter representing the condition of the electrolytic copper plating solution 13 can be calculated.
When performing the analysis, the Cu (I) species generated on the surface 37a of the working electrode 18 in the process of the deposition reaction of the copper plating film is restrained from being positioned on the surface 37a as the deposition reaction of the copper plating film proceeds. The leveler replaces the Cu (I) species located on the surface 37a as the deposition reaction of the copper plating film progresses, and the Cu (I) species is at least an accelerator and a complex. A parameter representing the condition of the electrolytic copper plating solution 13 can be obtained on the basis of a reaction mechanism that forms an accelerating effect and exhibits a promoting effect.
Since the parameters specified in this way are calculated based on the reaction mechanism model in the precipitation reaction represented by the above formula (1), the condition of the electrolytic copper plating solution 13 is specified accurately and quantitatively. be able to.
Moreover, using the parameters obtained in this manner, the physical properties and precipitation of the copper plating film can be stabilized by managing and maintaining the condition of the electrolytic copper plating solution 13 used in the plating apparatus (not shown). Can be maintained.

[Second Embodiment]
An electrolytic copper plating solution analyzer according to a second embodiment of the present invention will be described.
As shown in FIG. 1, the electrolytic copper plating solution analyzer 60 of the present embodiment includes an analysis unit 81 instead of the analysis unit 31 of the electrolytic copper plating solution analyzer 10 of the first embodiment.
The analysis unit 81 includes an analysis unit main body 92 instead of the analysis unit main body 42 of the analysis unit 31.
Hereinafter, a description will be given centering on differences from the first embodiment.

The analysis unit main body 92 uses the following formulas (5) to (8) instead of the above formulas (1) to (4) to analyze the measurement data of the potential η, as described in the first embodiment. And different.
The formulas (6), (7), and (8) are the same as the formulas (2), (3), and (4) in the first embodiment. In addition, among the constants and variables used in each mathematical expression, the description common to the first embodiment is omitted.

Here, k ₃ is the reaction rate inhibitor by the difference in adsorption rate is over time replaced by leveler.

The above formula (5) is a formula representing the change over time of the potential η when a reaction mechanism different from that of the first embodiment is assumed as the reaction mechanism of the precipitation reaction in the electrolytic copper plating solution 13.
Regarding the above formula (5), the reaction mechanism of the copper plating film deposition considered by the present inventor will be described.
When the copper electroplating solution 13 is energized, immediately after the copper plating film starts to be deposited on the cathode (cathode electrode) by electrolysis, the additive, the inhibitor, the accelerator, and the leveler are adsorbed on the negative electrode. Cover the surface of the copper plating film.
The copper plating film is deposited between the additive thin film layer adsorbed on the cathode surface and the cathode surface, and is taken in as a metal film. Note that immediately after the copper plating film starts to deposit, the order in which the additive adsorption effect is strong is the order of the inhibitor, the accelerator, and the leveler.

In the reduction reaction of Cu (II) ions to metallic copper (in other words, zero-valent Cu), Cu (I) ions are passed as an intermediate. Most Cu (I) is reduced to metallic copper, but some are combined with chlorine or promoter components as by-products to form and stabilize Cu (I) species, some of which are precipitated Stays on the metal copper surface.
For this reason, as the precipitation reaction of the copper plating film proceeds, the surface concentration of the Cu (I) species on the surface of the copper plating film increases. For example, this Cu (I) species corresponds to a Cu (I) complex formed from Cu (I) ions generated by the reaction between the promoter component in the electrolytic copper plating solution 13 and the electrode, and this is the electrode reaction. Since it has a catalytic action, a promoting effect appears.

Further, as the deposition reaction of the copper plating film proceeds, the concentration of Cu (I) species (for example, Cu (I) complex) in the vicinity of the surface of the cathode increases and immediately after the copper plating film starts to deposit, this Cu ( I) Displace the inhibitor with the species adsorbed on the cathode. Further, in the process of depositing the copper plating film, the leveler replaces the inhibitor adsorbed on the cathode.
In the deposition of the copper plating film, together with Cu (II) ions, an inhibitor component, a leveler component, and an accelerator component not complexed with Cu (I) ions are supplied from the electrolytic copper plating solution 13 to the surface of the cathode. On the other hand, desorption of the inhibitor component, leveler component, and accelerator component that existed on the cathode surface also occurs. The balance of the additive components on the electrode surface is balanced by these generation, adsorption, and desorption.

According to “Reference-2”, in the reaction mechanism in which the Cu (I) species complex on the cathode surface exhibits a promoting effect, the Cu (I) species are generated on the cathode surface as described above, and the cathode surface In addition to those adhered to the surface, there are those produced on the cathode surface and then desorbed from the cathode, and those produced in the electrolytic copper plating solution 13 (for example, the anode electrode surface in the electrolytic copper plating solution 13). .
Such a Cu (I) species not present on the cathode surface is considered to exhibit a different acceleration effect from the Cu (I) species on the cathode surface. When this Cu (I) species not present on the cathode surface moves to the cathode surface by diffusion, it participates in the copper plating deposition reaction of the cathode and exhibits an accelerating effect.

When the reaction mechanism of the precipitation reaction described above is applied to the reaction in the analytical container 12 of the electrolytic copper plating solution analyzer 60, the working electrode 18 which is the cathode in the process of the copper precipitation reaction during the measurement of the potential η. The Cu (I) species generated on the surface 37a replace the inhibitor on the surface 37a as the precipitation reaction progresses, and the leveler replaces the inhibitor, and this Cu (I) species is at least an accelerator. It becomes a reaction mechanism of forming a complex and showing a promoting effect.
In addition, a promoter does not show a promoting effect by itself, but forms a complex with a Cu (I) species and is responsible for stabilizing a chemically unstable Cu (I) species. A chemically unstable Cu (I) species forms a complex with at least an accelerator and exhibits a promoting effect. For example, a chemically unstable Cu (I) species forms a complex with a promoter, a decomposition product of the promoter, chlorine, and the like, and exhibits a promoting effect.

About the background which obtained said Formula (5)-(8), a different point from said Formula (1)-(4) in the said 1st Embodiment is demonstrated.
As described in the first embodiment, in the precipitation reaction in the electrolytic copper plating solution 13, the above formulas (13) and (14) are established for the current density I and the potential η.

Regarding changes in the coverages θ _i , θ _a , and θ _l , the inhibitor is adsorbed on the surface 37a at the initial stage of deposition of the copper plating film on the surface 37a based on the reaction mechanism of the present embodiment as described above. However, it is considered that the adsorbed inhibitor is replaced by the accelerator with time, and the inhibitor adsorbed on the surface 37a is replaced by the leveler.
Since the inhibitor coverage θ _i is replaced with the accelerator coverage θ _a and the leveler coverage θ _l , the inhibitor coverage with the amount replaced by the leveler (in other words, θ _i and θ _l ) is defined as θ _i ′. The coverage θ _i ′ is the coverage of the inhibitor before being replaced by the accelerator.
The coverages θ _i ′ and θ _l can be expressed as the following formulas (26) and (27) based on the diffusion formula, according to the model of the above-mentioned reference.

Since the sum of the coverage rate θ _i ′ and the coverage rate θ _a is “1”, the coverage rate θ _a can be expressed by the following equation (28).

Further, since the coverage ratio θ _i ′ is the sum of the coverage ratio θ _i and the coverage ratio θ _l , the coverage ratio θ _i can be expressed by the following formula (29).

  Substituting the above formulas (26) to (29) into the above formula (14), the following formula (30) is obtained.

In the above formula (30), when an inhibitor, an accelerator, and a leveler are included, the inhibitor adsorbed on the surface 37a is replaced by the accelerator over time due to the difference in adsorption speed of each component, and adsorbed on the surface 37a. It is a relational expression showing the time change of electric potential (eta) derived | led-out based on the model that the suppressed inhibitor was substituted by time by the leveler.
However, it has been found that there is a large difference between the potential obtained by actual measurement and the potential η calculated by the above equation (30).
Therefore, as a result of various studies, the present inventor has found that it is better to assume another reaction mechanism than to think that the accelerator is brought from the electrolytic copper plating solution 13 by diffusion.
For example, Cu (I) species generated on the surface 37a of the working electrode 18 in the process of the deposition reaction of the copper plating film may cause an inhibitor on the surface 37a of the working electrode 18 as the deposition reaction of the copper plating film proceeds. It is possible to explain the measurement results better by assuming a reaction mechanism in which the leveler replaces the inhibitor on the surface 37a of the working electrode 18 and the Cu (I) species itself exhibits a promoting effect. I understood.
Therefore, in the above formula (5), the reaction rate k in the above formula (30) is replaced with a factor including the current density I as shown in the above formula (20), as in the first embodiment.

Next, operation | movement of the electrolytic copper plating solution analyzer 60 of this embodiment is demonstrated centering on the electrolytic copper plating solution analysis method of this embodiment.
In order to specify the condition of the electrolytic copper plating solution 13 used in an appropriate plating apparatus (not shown) by the electrolytic copper plating solution analyzer 60, the preparation process, potential in the electrolytic copper plating solution analysis method of the present embodiment The measurement process and the analysis process are performed in this order.

  The preparation process and potential measurement process of the first embodiment are the same as the preparation process and potential measurement process of the first embodiment except that the electrolytic copper plating solution analyzer 60 is used instead of the electrolytic copper plating solution analyzer 10. It is the same process.

Next, the analysis process of this embodiment is performed. This step is different from the first embodiment in that it is performed by the analysis unit 81 instead of the analysis unit 31 of the first embodiment.
This process is automatically started by the analysis unit 81 when all the measurement data measured by the potential measurement unit 28 is transmitted to the analysis unit 81 during the measurement time t _m after the measurement time t _m has passed. The
In the present embodiment, the analysis unit main body 92 stores an analysis program for calculating parameters in the above equation (5). The analysis program calculates the parameters by fitting the measured data of the potential η sent from the potential measuring unit 28 by the above equation (5).
In copper electroplating solution analyzer, parameter _{(i i, i a, i} l, C a * / T i, k 3 · C l / T i) , each component of the plating solution (accelerator, inhibitor, and The effect of the leveler is quantified, and the state of the plating solution can be specified.
The analysis method used for the analysis program is not particularly limited. For example, it is possible to employ analysis methods such as curve fitting using the least square method, the gradient of the measured potential, and the average value of the measured potential.
In addition, constants used for analysis, for example, constants necessary for calculation of the above formulas (6) and (7) are stored in the analysis unit main body 92 in advance.

When the analysis unit body 92 executes the analysis program, _p 11 represented by the following formula as a parameter from _{(31) (35), p} 12, p 13, p 14, p 15 ( hereinafter, "parameter _p 11 _{~p 15} Is sometimes abbreviated as “.”).
In this embodiment, since the least square method is used, the analysis unit main body 92 sets an appropriate initial value for the parameters p _{11 to} p ₁₅ and executes the analysis program, so that the deviation from the measurement data is the least square method. The parameters p _{11 to} p ₁₅ are changed until it converges so as to be the smallest in FIG. In the present embodiment, the residual sum of squares S is also calculated.

The calculated parameters p _{11 to} p ₁₅ , the function η (t) determined by curve fitting, and the residual sum of squares S are displayed on the display 43 together with the graph of the measurement data.

These parameters _p 11 _{~p 15} is Condition copper electroplating solution 13, in other words, has a parameter that may be known inhibitor, Cu (I) species, and the state of the leveler.
For this reason, the combination of the parameters p _{11 to} p ₁₅ is a numerical value group that specifies the condition of the electrolytic copper plating solution 13.

The parameters p ₁₁ , p ₁₂ and p ₁₃ are the exchange current densities i _i , i _a and i _l , respectively. Inhibitors, Cu (I) species, and the respective effects of the leveler is large, the magnitude of the exchange current density _{i i, i a, i l} is changed.
Parameter _{p 14 are} the ^C a * / _{T i,} which is a parameter representing the ratio between the promoting effect and suppressing effect.
If the parameter p ₁₄ increases, it can be seen that the promoting effect is relatively increased with respect to suppressing effect. Further, the parameter p ₁₄ is reduced, it can be seen that the inhibitory effect is relatively increased with respect to promoting effect.
Parameter p ₁₅ are the _{k 3 · C l / T i} , the substitution reaction rate of the accelerator and leveler, which is a parameter representing a smoothing effect, a suppressive effect, the relationship.
If the parameter p ₁₅ increases, the smoothing effect increases. Further, when the parameter p ₁₅ is reduced, smoothing effect is reduced. The respective effects when departing from the range of the parameter p ₁₅ becomes excessive, problems occur.
For example, in the via filling plating, a phenomenon such as a decrease in the filling degree of the copper plating film in the via hole appears.

The condition of the electrolytic copper plating solution 13 specified by these parameters p _{11 to} p ₁₅ can be determined whether the condition is good or not by setting determination conditions in advance in the same manner as in the first embodiment. is there.
Such a determination may be made by the measurer by looking at each parameter displayed on the display 43, but the determination condition is stored in the analysis unit main body 92, and the analysis unit main body 92 determines the value of each parameter The determination may be made automatically by comparing the conditions. When the analysis unit main body 92 makes the determination, the determination result is displayed on the display 43 together with the numerical values of the respective parameters.
This completes the analysis process.

According to the electrolytic copper plating solution analyzer 60 of the present embodiment, the potential η between the working electrode 18 immersed in the analytical sample of the electrolytic copper plating solution 13 and the reference electrode 19 is measured, and the elapsed time t and the potential η are measured. Can be calculated, and a parameter representing the condition of the electrolytic copper plating solution 13 can be calculated.
When performing the analysis, the Cu (I) species generated on the surface 37a of the working electrode 18 in the process of the deposition reaction of the copper plating film is restrained from being positioned on the surface 37a as the deposition reaction of the copper plating film proceeds. The leveler replaces the inhibitor located on the surface 37a as the deposition reaction of the copper plating film proceeds, and the Cu (I) species forms a complex with at least the promoter. On the basis of the reaction mechanism indicating the acceleration effect, a parameter representing the condition of the electrolytic copper plating solution 13 can be obtained.
Since the parameters specified in this way are calculated based on the reaction mechanism model in the precipitation reaction represented by the above formula (5), the condition of the electrolytic copper plating solution 13 is specified accurately and quantitatively. be able to.
Moreover, using the parameters obtained in this manner, the physical properties and precipitation of the copper plating film can be stabilized by managing and maintaining the condition of the electrolytic copper plating solution 13 used in the plating apparatus (not shown). Can be maintained.

  As mentioned above, although 1st Embodiment and 2nd Embodiment were explained in full detail about preferable embodiment of this invention, this invention is not limited to this specific embodiment, and is described in the claim. Various modifications and changes can be made within the scope of the gist of the present invention.

  For example, in each of the above embodiments, the case of using an electrolytic copper plating solution analyzer separated from a plating apparatus (not shown) has been described as an example. For example, a plating tank (not shown) of a plating apparatus is used. 1) and the analytical container 12 shown in FIG. 1 are connected by a line (not shown), and the electrolytic copper plating solution in the plating tank is guided into the analytical container 12 through this line. Good.

In the description of each of the above embodiments, the leveler replacement target is different in the assumption of the reaction mechanism in the analysis step. That is, in the first embodiment, as the deposition reaction of the copper plating film using the electrolytic copper plating solution 13 proceeds, the leveler in the electrolytic copper plating solution 13 is Cu (positioned on the surface 37a of the working electrode 18). I) Assume a reaction mechanism to replace the species. On the other hand, in 2nd Embodiment, the reaction mechanism in which a leveler substitutes the inhibitor located in the surface 37a is assumed.
In the leveler used for the copper electroplating solution, it is considered that any substitution occurs, but depending on the type of the leveler and the type of each component in the copper electroplating solution 13, the rate at which each substitution occurs is different. Conceivable.
Therefore, in order to specify the condition of the electrolytic copper plating solution 13 with higher accuracy, the fitting error between the fitting curve and the measurement data when the parameters are calculated among the above formulas (1) and (5) is small. It is preferable that the relational expression can be selected.
For example, it is preferable that the analysis unit incorporates an analysis program based on both the formulas (1) and (5) so that the user can select which one to use.
At this time, as a selection criterion, a criterion of selecting a smaller residual sum of squares can be employed.
When the type of electrolytic copper plating solution 13 to be analyzed and analyzed is determined, an evaluation experiment can be performed in advance and an analysis program more suitable for the electrolytic copper plating solution 13 can be stored.

  In the description of the above embodiments, the electrolytic copper plating solution analyzer and the electrolytic copper plating solution analysis method have been described, but the present invention is not limited to the analysis of electrolytic copper plating. For example, it can be applied to the analysis of electroplating solutions other than copper plating containing additives including accelerators, inhibitors, and levelers using a constant current electrolysis method. For example, the present invention can be similarly applied to an electro nickel plating solution analyzer and an electro nickel plating solution analysis method. However, unlike the reaction mechanism of electrolytic copper plating, in the case of electrolytic nickel plating, the parameters for specifying the condition of the electrolytic nickel plating solution are calculated based on the reaction mechanism in which the added accelerator exhibits a promoting effect. To do. In this case, the coefficients of the above formulas (1) to (8) may be read as “during the precipitation reaction of the copper plating film” as “during the precipitation reaction of the nickel plating film”.

Examples of the above embodiments and reference examples will be described below, but the present invention is not limited to the following examples.
In Examples 1 to 4 and Reference Examples 1 and 2, the curve fitting properties are mainly compared.
Moreover, in Examples 5-14 and Reference Examples 3-7, the comparison which specifies the state of a plating solution is performed.
FIG. 3 is a graph showing an example of measurement data and analysis results in Examples 1 and 2 using the electrolytic copper plating apparatus of the first embodiment of the present invention. FIG. 4 is a graph showing an example of measurement data and analysis results in Examples 3 and 4 using the electrolytic copper plating apparatus of the second embodiment of the present invention. FIG. 5 is a graph showing an example of measurement data and analysis results in Reference Examples 1 and 2 using the electrolytic copper plating apparatus of the Reference Example.
In each graph, the horizontal axis represents elapsed time t (sec), and the vertical axis represents potential η (V). The potential η is a value converted to the copper redox potential standard.

  In Examples 1 to 14 and Reference Examples 1 to 7, the electrolytic copper plating solution was analyzed by the following method using the electrolytic copper plating solution 13 being used in a plurality of plating apparatuses (not shown).

<Measurement sample>
As measurement samples, measurement samples P ₁ and P ₂ were taken from the electrolytic copper plating solution 13 in use of a first plating apparatus (not shown). Samples for measurement P ₁ and P ₂ are electrolytic copper plating solutions 13 collected at different times. Therefore, the condition of the additives in the measurement samples P ₁ and P ₂ is not the same.
Measurement samples P _{3 to} P ₇ were collected from the electrolytic copper plating solution 13 in use in a second plating apparatus (not shown) different from the first plating apparatus. The compositions of the plating solutions of the first and second plating apparatuses are different.
Among the measurement samples P _{3 to} P ₇ , P ₃ and P ₄ are samples in which the state of the plating solution is bad, and P _{5 to} P ₇ are samples in which the state is good.
Here, whether the state of the plating solution was good or bad was determined based on whether the filling property by bottom-up deposition of via holes was good or bad. Specifically, by observing the cross-section of the via hole after plating, it was determined that “good” when the via hole was filled 50% or more, and “bad” when the via hole was filled less than 50%. .
In each measurement, the electrolytic copper plating solution 13 was separated from the measurement samples P _{1 to} P ₇ and used for measurement.
Samples 1-1, 1-2, and _1-3 were separated from the measurement sample P1. Therefore, the conditions of the samples 1-1, 1-2, and 1-3 as the electrolytic copper plating solution are the same.
Similarly, samples n-1, n-2, and n-3 were separated from the measurement samples P _n (n = 2,..., 7). For this reason, the conditions as an electrolytic copper plating solution of the samples n-1, n-2, and n-3 are the same.

[Examples 1 and 2]
In Examples 1 and 2, Samples 1-1 and 2-1 were analyzed using an electrolytic copper plating solution analyzer 10, respectively.
A platinum disk electrode was used as the working electrode 18. The area of the surface 37a was 4πmm ² .
As the reference electrode 19, an electrode made of silver / silver chloride (Ag / AgCl) was used. As the counter electrode 21, an electrode made of cylindrical copper having a diameter of 8 mm was used.
The measurement conditions of the potential η in the potential measurement unit 28 are as follows: the current density I at the working electrode 18 is 1 A / dm ² ; Was 30 ° C. (303.15 K).
The measurement data of Examples 1 and 2 are indicated by □ (sample 1-1) and Δ (sample 2-1) in the graph of FIG. In FIG. 3, the measurement data is thinned and displayed for easy viewing, but the actual measurement is performed at intervals of 1 second.
Among such measurement data, the conditions of samples 1-1 and 2-1 were analyzed by the analysis unit 31 using potential data in which the elapsed time t was in the range of 50 seconds to 1200 seconds.

The fitting curves fitted using the above equation (1) are shown as curves 101 and 102 in FIG. A curve 101 (solid line) is a fitting curve of measurement data of the sample 1-1, and a curve 102 (dashed line) is a fitting curve of measurement data of the sample 2-1.
In the electrolytic copper plating solution analyzer 10, the graph shown in FIG. 3 is sequentially displayed on the display 43.
The parameters p _{1 to} p ₅ calculated by the analysis unit 31 are shown in Table 1 below.
However, the units of parameters p _{1 to} p ₃ are all mA / cm ² , the unit of p ₄ is 1 / cm, and the unit of p ₅ is 1 / sec (the same applies to Examples 5 to 9).
As constants used for the calculation, the gas constant R was 8.314 J / (mol · K), the transfer coefficient α was 0.5 eq / mol, the Faraday constant F was 96480 C / eq, and the molar density d of copper was 0.141 mol / mol. The valence n of cm ³ and copper is 2 eq / mol (the same applies to Examples 3 to 14).

[Examples 3 and 4]
In Examples 3 and 4, samples 1-2 and 2-2 were analyzed using the electrolytic copper plating solution analyzer 60, respectively. The conditions for the working electrode 18, the reference electrode 19, and the counter electrode 21 and the conditions for measuring the potential were the same as in Example 1.
The measurement data of Examples 3 and 4 are indicated by □ (sample 1-2) and Δ (sample 2-2) in the graph of FIG. In FIG. 4, the measurement data is thinned and displayed for easy viewing, but the actual measurement is performed at intervals of 1 second.
Among such measurement data, the analysis of the condition of the samples 1-2 and 2-2 was performed by the analysis unit 81 using potential data having an elapsed time t in the range of 50 seconds to 1200 seconds.

The fitting curves fitted using the above equation (5) are shown as curves 103 and 104 in FIG. A curve 103 (solid line) is a fitting curve of the measurement data of the sample 1-2, and a curve 104 (broken line) is a fitting curve of the measurement data of the sample 2-2.
In the electrolytic copper plating solution analyzer 60, the graph shown in FIG. 4 is sequentially displayed on the display 43.
The parameters p _{11 to} p ₁₅ calculated by the analysis unit 81 are shown in Table 2 below.
However, the units of parameters p _{11 to} p ₁₃ are all mA / cm ² , the unit of p ₁₄ is 1 / cm, and the unit of p ₁₅ is 1 / sec (the same applies to Examples 10 to 14).

[Reference Examples 1 and 2]
In Reference Examples 1 and 2, Samples 1-3 and 2-3 were analyzed using the electrolytic copper plating solution analyzer of the Reference Example, respectively.
The electrolytic copper plating solution analyzer of the reference example includes the electrolytic copper plating solution analyzer 10 used in Examples 1 and 2 above, the electrolytic copper plating solution analyzer 60 used in Examples 3 and 4 above, and the analysis of the analysis unit. Only the program is different.
That is, in the apparatus configuration and analysis conditions of the electrolytic copper plating solution analyzer of the reference example, the working electrode, the reference electrode, the current density I at the working electrode, the rotational speed of the working electrode, and the sample 1-3 at the time of measuring the potential η, The temperature conditions of 2-3 were the same as those in Examples 1 and 2.
The analysis program of the electrolytic copper plating solution analyzer of the reference example performed an analysis using the following formula (36) as a relational expression representing the time change of the potential η assuming a reaction mechanism that does not consider the influence of the leveler in the precipitation reaction. .

  The above equation (36) is a relational expression similar to that obtained by deleting the third term of the above equation (1) and the third term of the above equation (5).

The measurement data of Reference Examples 1 and 2 are indicated by □ (sample 1-3) and Δ (sample 2-3) in the graph of FIG. In FIG. 5, the measurement data is thinned and displayed for easy viewing, but the actual measurement is performed at intervals of 1 second.
Among such measurement data, the conditions of samples 1-3 and 2-3 were analyzed by the analysis unit using potential data in which the elapsed time t was in the range of 50 seconds to 1200 seconds.

  The fitting curves fitted using the above equation (36) are shown as curves 201 and 202 in FIG. A curve 201 (solid line) is a fitting curve of measurement data of the sample 1-3, and a curve 202 (dashed line) is a fitting curve of measurement data of the sample 2-3.

Analysis results of Examples 1 and 3 and Reference Example 1 (curve 101 in FIG. 3, curve 103 in FIG. 4, curve 201 in FIG. 5) corresponding to the condition of the sample, and analysis in Examples 2 and 4 and Reference Example 2 In order to compare the results (curve 102 in FIG. 3, curve 104 in FIG. 4, curve 202 in FIG. 5), the following table 3 shows the residual sum of squares S (V ² ) in each analysis.

<Consideration of analysis results of Examples 1 to 4 and Reference Examples 1 and 2>
As shown in Table 1, the parameters p ₂ and p ₄ were larger in Example 1 than in Example 2.
This is presumably because the action of the Cu (I) species, which forms a complex with at least the accelerator with respect to the inhibitor and exhibits a promoting effect, was excessive in Example 1. According to “Reference 2”, when the function of Cu (I) species that forms a complex with at least an accelerator and exhibits an acceleration effect becomes excessive, the filling characteristics of the via hole are deteriorated. Therefore, according to the analysis using a copper electroplating solution analyzing device 10, the use of copper electroplating solution P _1, it is seen that the filling characteristics of the via hole deteriorates.
As shown in Table 2, the parameters p ₁₂ and p ₁₄ were larger in Example 3 than in Example 4.
This is presumably because the action of the Cu (I) species, which forms a complex with the accelerator and the like with respect to the inhibitor and exhibits a promoting effect, was excessive in Example 3. According to “Reference 2”, when the function of Cu (I) species that forms a complex with an accelerator or the like and exhibits a promoting effect becomes excessive, the filling characteristics of the via hole are deteriorated. Therefore, according to the analysis using a copper electroplating solution analyzing device 60, the use of copper electroplating solution P _1, it is seen that the filling characteristics of the via hole deteriorates.

As shown in Table 3, the residual sum of squares S in Examples 1 and 3 and Reference Example 1 using samples 1-1, 1-2, and _1-3 separated from the measurement sample P1 having the same condition , The residual sum of squares S of Examples 1 and 3 are substantially the same, and the residual sum of squares S of Reference Example 1 is about 10% larger than these.
It can be said that the smaller the residual sum of squares S is, the better the fitting curve approximates the measurement data, so that the calculated parameter represents the condition of the electrolytic copper plating solution 13 better. For this reason, the additive can be managed more accurately as the residual sum of squares S is smaller.
Therefore, in Examples 1 and 3, the analysis using the electrolytic copper plating solution analyzers 10 and 60 in consideration of the effect of the leveler is an analysis in which the effect of the leveler is not considered as in the electrolytic copper plating solution analyzer of the reference example. It was confirmed that the additive can be managed with higher accuracy than
Further, embodiments using Sample 2-1, 2-2, 2-3, which aside from the measurement sample _{P 2} having the same conditions Examples 2 and 4, when comparing the residual sum of squares S in Reference Example 2, implemented Examples 4 and 2 and Reference Example 1 increase in this order. In particular, Reference Example 1 is about 22% and about 10% larger than Examples 4 and 2, respectively.
Therefore, in Examples 2 and 4, the analysis using the electrolytic copper plating solution analyzers 10 and 60 in consideration of the effect of the leveler is an analysis in which the effect of the leveler is not considered as in the electrolytic copper plating solution analyzer of the reference example. It was confirmed that the additive can be managed with higher accuracy than

[Examples 5 to 9]
In Examples 5 to 9, Samples 3-1, 4-1, 5-1, 6-1 and 7-1 were analyzed using the electrolytic copper plating solution analyzer 10. The conditions for the working electrode 18, the reference electrode 19, and the counter electrode 21 and the conditions for measuring the potential were the same as in Example 1.
Among such measurement data, the sample data 3-1, 4-1, 5-1, 6-1, 7- is analyzed by the analysis unit 31 using potential data in which the elapsed time t is in the range of 50 seconds to 1200 seconds. The condition 1 was analyzed.

Tables 4 and 5 below show the parameters p _{1 to} p ₅ calculated by the analysis unit 31 and the determination results of the state of the plating solution.

[Examples 10 to 14]
In Examples 10 to 14, samples 3-2, 4-2, 5-2, 6-2, and 7-2 were analyzed using the electrolytic copper plating solution analyzer 60, respectively. The conditions for the working electrode 18, the reference electrode 19, and the counter electrode 21 and the conditions for measuring the potential were the same as in Example 1.
Among such measurement data, using the potential data in which the elapsed time t is in the range of 50 seconds to 1200 seconds, the analysis unit 81 causes the samples 3-2, 4-2, 5-2, 6-2, 7- The condition of 2 was analyzed.

Tables 6 and 7 below show the parameters p _{11 to} p ₁₅ calculated by the analysis unit 81 and the determination results of the state of the plating solution.

[Reference Examples 3 to 7]
In Reference Examples 3 to 7, Samples 3-3, 4-3, 5-3, 6-3, and 7-3, respectively, using the electrolytic copper plating solution analyzer of Reference Example, as in Reference Examples 1 and 2, respectively. Was analyzed.
Among the measurement data, the potential data of the elapsed time t in the range of 50 seconds to 1200 seconds is used to analyze the condition of the samples 3-3, 4-3, 5-3, 6-3, 7-3 by the analysis unit Analysis was performed.

In the electrolytic copper plating solution analyzer of the reference example, when the analysis program of the above formula (36) is executed, p ₂₁ , p ₂₂ and p ₂₃ represented by the following formulas (37) to (39) are calculated as parameters. .

Tables 8 and 9 below show the parameters p _{21 to} p ₂₃ calculated by the analysis unit and the determination results of the state of the plating solution.

<Determination of plating solution state>
In Examples 5 to 9, the parameters p _{1 to} p ₅ were specified, and “good” and “bad” of the state of the plating solution to be analyzed were determined by the combination of the parameters p _{1 to} p ₅ . For this reason, individual determination criteria for determining that the state of the plating solution to be analyzed is “good” is provided for each of the parameters p _{1 to} p ₅ . Further, as a combination criterion parameter p ₁ ~p _5, only if all of the individual criteria parameters p ₁ ~p ₅ is "good", and the state of the plating solution to be determined as "good". That is, if there is one or more parameters that do not satisfy the individual determination criteria among the parameters p _{1 to} p ₅ , the state of the plating solution is determined to be “bad”.
As shown in Table 5, "good" range in the individual criteria parameters _{p 1} is, 1.5 mA / cm ² or more, was 4.0 mA / cm ² or less.
The “good” range in the individual determination criterion of the parameter p ₂ was set to 0.08 mA / cm ² or more and 0.20 mA / cm ² or less.
"Good" range in the individual criteria parameter _{p 3} is, 0.07 mA / cm ² or more, it was 0.15 mA / cm ² or less.
"Good" range in the individual criteria parameter _{p 4} is, 20.0 cm ^-1 or more, and a 60.0cm ^-1 or less.
The “good” range in the individual determination criterion of the parameter p ₅ is set to 0.01 sec ⁻¹ or more and 0.1 sec ⁻¹ or less.
Table 5 shows the evaluation of “within range” and “out of range” with respect to the individual determination criteria in each example, and the “good” and “bad” evaluations based on the combination determination results are shown in the “analysis determination result” column. .
“Good” and “Bad” shown in the “Measurement determination result” column indicate the results of determining the via hole filling characteristics based on the measurement for each sample in advance.

In Examples 10 to 14, the parameters p _{11 to} p ₁₅ were specified, and “good” and “bad” of the state of the plating solution to be analyzed were determined by the combination of the parameters p _{11 to} p ₁₅ . For this reason, an individual determination criterion for determining that the state of the plating solution to be analyzed is “good” is provided for each of the parameters p _{11 to} p ₁₅ . Further, as a combination criterion parameter p ₁₁ ~p _15, only if all of the individual criteria parameters p ₁₁ ~p ₁₅ is "good", and the state of the plating solution to be determined as "good". That is, if there is one or more parameters that do not satisfy the individual determination criteria among the parameters p _{11 to} p ₁₅ , the state of the plating solution is determined to be “bad”.
As shown in Table 7, "good" range in the individual criteria parameters _{p 11} is, 0.20mA / cm ² or more, was 0.38mA / cm ² or less.
"Good" range in the individual criteria parameters _{p 12} is, 0.35 mA / cm ² or more, it was 0.46 mA / cm ² or less.
The “good” range in the individual determination criterion of the parameter p ₁₃ is set to 0.07 mA / cm ² or more and 0.12 mA / cm ² or less.
"Good" range in the individual criteria parameters _{p 14} is, 10.0 cm ^-1 or more, was 30.0 cm ^-1 or less.
The “good” range in the individual determination criterion of the parameter p ₁₅ is set to be −5.0 × 10 ⁻⁵ sec ⁻¹ or more and −1.5 × 10 ⁻⁵ sec ⁻¹ or less.
Table 7 shows the evaluation of “within range” and “out of range” with respect to the individual determination criteria in each example, and the evaluation of “good” and “bad” by the combination determination is shown in the “analysis determination result” column.
“Good” and “Bad” shown in the “Measurement determination result” column indicate the results of determining the via hole filling characteristics based on the measurement for each sample in advance.

In Reference Examples 3 to 7, the parameters p _{21 to} p ₂₃ were specified, and “good” and “bad” of the state of the plating solution to be analyzed were determined by the combination of the parameters p _{21 to} p ₂₃ . For this reason, individual determination criteria for determining that the state of the plating solution to be analyzed is “good” is provided for each of the parameters p _{21 to} p ₂₃ . Further, as a combination criterion parameter p ₂₁ ~p _23, only if all of the individual criteria parameters p ₂₁ ~p ₂₃ is "good", and the state of the plating solution to be determined as "good". That is, if there is one or more parameters that do not satisfy the individual determination criteria among the parameters p _{21 to} p ₂₃ , the state of the plating solution is determined to be “bad”.
As shown in Table 9, the “good” range in the individual determination criterion of the parameter p ₂₁ was set to 0.015 mA / cm ² or more and 0.023 mA / cm ² or less.
The “good” range in the individual determination criterion of the parameter p ₂₂ is set to 0.08 mA / cm ² or more and 0.20 mA / cm ² or less.
The “good” range in the individual determination criterion of the parameter p ₃₃ is set to 15.0 cm ⁻¹ or more and 30.0 cm ⁻¹ or less.
Table 9 shows “in range” and “out of range” evaluations for the individual determination criteria in each reference example, and “good” and “bad” evaluations by combination determination are shown in the “analysis determination result” column.
“Good” and “Bad” shown in the “Measurement determination result” column indicate the results of determining the via hole filling characteristics based on the measurement for each sample in advance.

<Consideration of judgment results>
According to Table 5, in Examples 5-9, the analysis determination result of each Example corresponds with the measurement determination result. Therefore, according to Examples 5 to 9, by specifying the parameters p ₁ to p ₅ , the case where the state of the plating solution is “good” and the case where it is “bad” can be separated.
According to Table 7, in Examples 10-14, the analysis determination result of each Example is in agreement with the actual measurement determination result. Therefore, according to Examples 10 to 14, by specifying the parameters p ₁₁ to p ₁₅ , the case where the state of the plating solution is “good” and the case where it is “bad” can be separated.
According to Table 9, in Reference Examples 3 to 7, the analysis determination results of each Reference Example are the same as the actual measurement determination results in Reference Examples 3 to 6, but in Reference Example 7 are the same as the actual measurement determination results. Absent. In Reference Example 7, the plating solution in the “good” state was erroneously determined as “bad”.
Thus, in the reference example, since the parameter based on the reaction mechanism that does not consider the leveler is specified, the state of the plating solution cannot be specified with high accuracy.
However, since the plating solution in a bad state is not erroneously determined as “good”, the evaluation is on the safety side.

  The present invention relates to an electrolytic copper plating solution used in various applications such as decoration, copper foil manufacturing, electronic parts, etc., particularly for high-density mounting substrates, semiconductor package substrates, and contact holes and via holes formed in semiconductor substrates. The present invention can be applied to an electrolytic copper plating solution analyzer and an electrolytic copper plating solution analysis method, which are analysis devices for an electrolytic copper plating solution used when forming a conductor.

DESCRIPTION OF SYMBOLS 10, 60 Electro copper plating solution analyzer 11 Stand 11A Stage part 12 Analytical container 13 Electro copper plating solution 18 Working electrode 19 Reference electrode 21 Counter electrode 23 Rotation drive part 25 Controller 26 Current generation part 28 Electric potential measurement part 31, 81 Analysis Part 35 Exterior member 35a Front end surface (front end of exterior member)
35A Working electrode body housing (recessed at the center of the tip surface)
37 working electrode body 37a surface (working electrode surface)
39 Lead wires 42 and 92 Analysis unit main body 43 Display 44 Keyboard t Elapsed time η Potential

Claims (8)

An electrolytic copper plating solution analyzer for performing analysis and analysis for specifying the condition of an electrolytic copper plating solution containing an additive including an accelerator, an inhibitor, and a leveler using a constant current electrolysis method,
A container for analysis containing a part of the electrolytic copper plating solution as a sample for analysis;
A working electrode that is immersed in the electrolytic copper plating solution contained in the analytical container and receives and receives electrons;
A reference electrode that is immersed in the electrolytic copper plating solution housed in the analytical container and serves as a reference when determining the potential of the working electrode;
A counter electrode immersed in the electrolytic copper plating solution housed in the analytical container;
A rotation drive unit for rotating the working electrode at a constant speed;
Between the working electrode and the counter electrode, a current generating unit for passing a current having a constant current density,
A potential measuring unit for measuring a potential between the working electrode and the reference electrode;
An analysis unit for analyzing a relationship between an elapsed time from the flow of the current and the potential;
Have
The analysis unit
When analyzing the relationship between the elapsed time and the electric potential, the Cu (I) species generated on the surface of the working electrode during the deposition reaction of the copper plating film is accompanied by the progress of the deposition reaction of the copper plating film. Then, the inhibitor located on the surface of the working electrode is replaced, and the Cu (I) located on the surface of the working electrode as the leveler progresses in the deposition reaction of the copper plating film. A parameter representing the condition of the copper electroplating solution is calculated based on a reaction mechanism in which the Cu (I) species forms a complex with at least the promoter and exhibits a promoting effect. Identify the condition of the electrolytic copper plating solution using parameters,
Electrolytic copper plating solution analyzer. The analysis unit
Analyzing the relationship between the elapsed time measured by the potential measuring unit and the potential based on the following formulas (1) to (4),
_2. The electrolytic copper plating solution analyzer according to claim 1, wherein i _i , i _a , i ₁ , C _a ^* / T _i , and k ₂ · C ₁ / T _i are calculated as the parameters.

Where η is the potential, T is the constant temperature, I is the current density, t is the elapsed time, i _i is the exchange current density during the deposition reaction of the copper plating film when the inhibitor is present, i _a is the exchange current density during the deposition reaction of the copper plating film in the exchange current density during the deposition reaction of the copper plating film when there is the Cu (I) species, the i _l said leveler is present, C _a is the concentration of the accelerator in the solution bulk, C _l is the concentration of the leveler in the solution bulk, T _i is the saturated coating amount of the inhibitor on the surface of the copper plating film, and k is the inhibitor depending on the difference in adsorption rate. Is the reaction rate at which the Cu (I) species is replaced with time by the Cu (I) species, k ₂ is the reaction rate at which the Cu (I) species are replaced by the leveler with time due to the difference in adsorption rate, R is the gas constant, α Is a mobile , F is Faraday constant, d is the molar density of copper, n represents a valence of copper. An electrolytic copper plating solution analyzer for performing analysis and analysis for specifying the condition of an electrolytic copper plating solution containing an additive including an accelerator, an inhibitor, and a leveler using a constant current electrolysis method,
A container for analysis containing a part of the electrolytic copper plating solution as a sample for analysis;
A working electrode that is immersed in the electrolytic copper plating solution contained in the analytical container and receives and receives electrons;
A reference electrode that is immersed in the electrolytic copper plating solution housed in the analytical container and serves as a reference when determining the potential of the working electrode;
A counter electrode immersed in the electrolytic copper plating solution housed in the analysis container; a rotation drive unit that rotates the working electrode at a constant speed;
Between the working electrode and the counter electrode, a current generating unit for passing a current having a constant current density,
A potential measuring unit for measuring a potential between the working electrode and the reference electrode;
An analysis unit for analyzing a relationship between an elapsed time from the flow of the current and the potential;
Have
The analysis unit
When analyzing the relationship between the elapsed time and the electric potential, the Cu (I) species generated on the surface of the working electrode during the deposition reaction of the copper plating film is accompanied by the progress of the deposition reaction of the copper plating film. Then, the inhibitor located on the surface of the working electrode is replaced, and the leveler replaces the inhibitor located on the surface of the working electrode as the deposition reaction of the copper plating film proceeds. Then, based on a reaction mechanism in which the Cu (I) species forms a complex with at least the promoter and exhibits a promoting effect, a parameter representing the condition of the electrolytic copper plating solution is calculated, and the parameter is used. To identify the condition of the copper electroplating solution,
Electrolytic copper plating solution analyzer. The analysis unit
Analyzing the relationship between the elapsed time measured by the potential measuring unit and the potential based on the following formulas (5) to (8),
4. The electrolytic copper plating solution analyzer according to claim 3, wherein i _i , i _a , i _l , C _a ^* / T _i , and k ₃ · C _l / T _i are calculated as the parameters. 5.

Where η is the potential, T is the constant temperature, I is the current density, t is the elapsed time, i _i is the exchange current density during the deposition reaction of the copper plating film when the inhibitor is present, i _a is the exchange current density during the deposition reaction of the copper plating film in the exchange current density during the deposition reaction of the copper plating film when there is the Cu (I) species, the i _l said leveler is present, C _a is the concentration of the accelerator in the solution bulk, C _l is the concentration of the leveler in the solution bulk, T _i is the saturation coating amount of the inhibitor on the surface of the copper plating film, and k is the suppression due to the difference in adsorption rate. the reaction rate, k ₃ is the reaction rate, R represents the gas constant, wherein the inhibitor by the difference in adsorption rate is over time replaced by the leveler agent is over time replaced by the Cu (I) species, alpha movement coefficient F is Faraday constant, d is the molar density of copper, n represents a valence of copper. An electrolytic copper plating solution analysis method for specifying a condition of an electrolytic copper plating solution containing an additive including a promoter, an inhibitor, and a leveler using a constant current electrolytic method,
A preparation step of immersing the working electrode, the reference electrode, and the counter electrode in the electrolytic copper plating solution maintained at a constant temperature, and rotating the working electrode at a constant speed;
A potential measuring step of measuring a potential between the working electrode and the reference electrode by passing a current having a constant current density between the working electrode and the counter electrode;
An analysis step for analyzing a relationship between an elapsed time from the flow of the current and the electric potential;
Have
In the analysis step,
When analyzing the relationship between the elapsed time and the electric potential, the Cu (I) species generated on the surface of the working electrode during the deposition reaction of the copper plating film is accompanied by the progress of the deposition reaction of the copper plating film. Then, the inhibitor located on the surface of the working electrode is replaced, and the Cu (I) located on the surface of the working electrode as the leveler progresses in the deposition reaction of the copper plating film. A parameter representing the condition of the copper electroplating solution is calculated based on a reaction mechanism in which the Cu (I) species forms a complex with at least the promoter and exhibits a promoting effect. Identify the condition of the electrolytic copper plating solution using parameters,
Electrolytic copper plating solution analysis method. In the analysis step,
Analyzing the relationship between the elapsed time measured in the potential measurement step and the potential based on the following formulas (1) to (4),
The electrolytic copper plating solution analysis method according to claim 5, wherein i _i , i _a , i _l , C _a ^* / T _i , and k ₂ · C _l / T _i are calculated as the parameters.

Where η is the potential, T is the constant temperature, I is the current density, t is the elapsed time, i _i is the exchange current density during the deposition reaction of the copper plating film when the inhibitor is present, i _a is the exchange current density during the deposition reaction of the copper plating film in the exchange current density during the deposition reaction of the copper plating film when there is the Cu (I) species, the i _l said leveler is present, C _a is the concentration of the accelerator in the solution bulk, C _l is the concentration of the leveler in the solution bulk, T _i is the saturation coating amount of the inhibitor on the surface of the copper plating film, and k is the suppression due to the difference in adsorption rate. The reaction rate at which the agent is displaced with time by the Cu (I) species, k ₂ is the reaction rate at which the Cu (I) species are replaced with time by the difference in adsorption rate, R is the gas constant, α is a shift Coefficient, F is Faraday constant, d is the molar density of copper, n represents a valence of copper. An electrolytic copper plating solution analysis method for specifying a condition of an electrolytic copper plating solution containing an additive including a promoter, an inhibitor, and a leveler using a constant current electrolytic method,
A preparation step of immersing the working electrode, the reference electrode, and the counter electrode in the electrolytic copper plating solution maintained at a constant temperature, and rotating the working electrode at a constant speed;
A potential measuring step of measuring a potential between the working electrode and the reference electrode by passing a current having a constant current density between the working electrode and the counter electrode;
An analysis step for analyzing a relationship between an elapsed time from the flow of the current and the electric potential;
Have
In the analysis step,
When analyzing the relationship between the elapsed time and the electric potential, the Cu (I) species generated on the surface of the working electrode during the deposition reaction of the copper plating film is accompanied by the progress of the deposition reaction of the copper plating film. Then, the inhibitor located on the surface of the working electrode is replaced, and the leveler replaces the inhibitor located on the surface of the working electrode as the deposition reaction of the copper plating film proceeds. Then, based on a reaction mechanism in which the Cu (I) species forms a complex with at least the promoter and exhibits a promoting effect, a parameter representing the condition of the electrolytic copper plating solution is calculated, and the parameter is used. A method for analyzing an electrolytic copper plating solution, wherein the condition of the electrolytic copper plating solution is specified. In the analysis step,
Analyzing the relationship between the elapsed time measured in the potential measuring step and the potential based on the following formulas (5) to (8),
The electrolytic copper plating solution analysis method according to claim 7, wherein i _i , i _a , i _l , C _a ^* / T _i , and k ₃ · C _l / T _i are calculated as the parameters.

Where η is the potential, T is the constant temperature, I is the current density, t is the elapsed time, i _i is the exchange current density during the deposition reaction of the copper plating film when the inhibitor is present, i _a is the exchange current density during the deposition reaction of the copper plating film in the exchange current density during the deposition reaction of the copper plating film when there is the Cu (I) species, the i _l said leveler is present, C _a is the concentration of the accelerator in the solution bulk, C _l is the concentration of the leveler in the solution bulk, T _i is the saturation coating amount of the inhibitor on the surface of the copper plating film, and k is the suppression due to the difference in adsorption rate. the reaction rate, k ₃ is the reaction rate, R represents the gas constant, wherein the inhibitor by the difference in adsorption rate is over time replaced by the leveler agent is over time replaced by the Cu (I) species, alpha movement coefficient F is Faraday constant, d is the molar density of copper, n represents a valence of copper.

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