JP3365497B2 - Hydrogen peroxide electrode and hydrogen peroxide sensor and measuring device using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a technique for detecting and quantifying hydrogen peroxide in a chemical solution, and in particular,
The present invention relates to a technique for quantitatively determining with high accuracy and reproducibility hydrogen peroxide contained in various chemicals used in the manufacture of semiconductor devices and chemicals used in sterilization and disinfection steps in food manufacturing processes.

[0002]

2. Description of the Related Art A chemical liquid using hydrogen peroxide as a reducing agent is widely used in various processes for manufacturing semiconductor devices. Further, in the food manufacturing process, a chemical solution containing hydrogen peroxide is used for the purpose of sterilization and disinfection. In these processes, when the hydrogen peroxide concentration fluctuates, the properties of the chemical solution fluctuate significantly, so in terms of quality control,
It is necessary to strictly control the concentration of hydrogen peroxide in the chemical solution.

As a method for measuring the concentration of hydrogen peroxide in a chemical solution, conventionally, concentration measurement by absorbance measurement has been generally performed. That is, the concentration of hydrogen peroxide was quantified by measuring the absorbance in the absorption band of hydrogen peroxide of the chemical solution to be measured and comparing it with the calibration curve data. Japanese Patent Application Laid-Open No. 8-136450 discloses an example of a hydrogen peroxide concentration measuring device that measures by such a method. The schematic structure of this device is shown in FIG. In this apparatus, pure water is constantly sent by the pump 61, and the absorbance at a predetermined wavelength in the ultraviolet region is continuously measured by the ultraviolet absorption measuring unit 86 including the flow cell 86b. Ultraviolet absorption measurement shows that absorption by ammonia is negligible at 240 nm
It is said that it is desirable to perform at the above wavelength. The measurement is performed in the following four steps. In the first step, the flow path switching valve 62 and the flow path switching valve 72 are set to a solid line state, the pump 63 causes the cleaning chemical solution to be in the loop 66, and the pump 73 causes the sulfuric acid solution to be in the loop 76a.
Liquid is sent to 76b, and the loop is filled with each liquid.
The cleaning chemical solution heated to 60 ° C. is cooled by the cooler 81, and the bubbles entering the pipe together with the cleaning chemical solution are removed by the defoamer 8
Excluded by 2. In the second step, the flow path switching valve 62 and the flow path switching valve 72 are set in the broken line state. As a result, the pure water flowing out of the pump 61 is looped 76
a, loop 66, loop 76b, and then mixer 8
Enter 5. The cleaning chemical solution and the sulfuric acid solution are mixed in the mixer 85 by the flow inside the thin tube, and then enter the ultraviolet absorption measurement unit 86. The absorbance at this time depends only on the hydrogen peroxide concentration in the cleaning liquid, and A or C in FIG. 11 is an example of the signal at this time. In the third step, only the flow path switching valve 62 is returned to the solid line, and the loop 66 is filled with the cleaning chemical liquid again. The loop 76a and the loop 76b are washed with pure water and filled with pure water. In the fourth step, the flow path switching valve 62
To the broken line. The cleaning chemical solution in the loop 66 is diluted with pure water and sent to the ultraviolet absorption measuring unit 86. The absorbance at this time is the absorbance of the cleaning chemical solution diluted with pure water, and depends on the concentrations of both hydrogen peroxide and ammonia. B or D in FIG. 11 is an example of the signal at this time. After that, the flow path switching valves 62 and 72 are returned to the state of the first step again.
Bring back. The absorbances of the obtained signals A and B are compared with the calibration curve data which is created by measuring the absorbances of several kinds of chemical liquids having known compositions and different compositions, and data processing is performed. Quantify hydrogen peroxide and ammonia in the chemical solution. It has been said that continuous monitoring of the chemical composition can be performed by repeating steps 1 to 4.

Another method is disclosed in Japanese Patent Laid-Open No. 3-175.
As disclosed in Japanese Patent No. 341, the near-infrared absorption spectrum of the chemical-processing aqueous solution for semiconductor process is compared with that of pure water, and an absorption band having a significant difference between the two is provided in the wavelength band of 800 to 1400 nm. Select the wavelength λi.
And 800 to 1400 nm of a standard sample of known concentration
The absorption spectrum was measured in determined absorbance A _i at wavelength lambda _i, calibration formula by analyzing the relationship between the concentration C and the absorbance A _i: Create a C = Σα _i A _i. In this equation, the constant α _i is determined by the type of drug, the wavelength λ _i , and the selected number of wavelengths λ _i . And 8 of the sample solution of unknown concentration
By measuring the absorption spectrum at 00 to 1400 nm to obtain the absorbance at the wavelength λ _i and substituting it into the calibration formula,
It is said that the concentration of the sample solution can be calculated quickly and accurately.

As a method other than the absorbance measurement, there is a measurement method using a hydrogen peroxide quantitative electrode. Fair fair 6-43
Japanese Patent No. 734 discloses an electrode member made of a metal having a catalytic action for decomposition of hydrogen peroxide and a connecting member to a power supply device to measure a current value after application, and mainly to a solution in a food field. A method of measuring the hydrogen peroxide concentration in a sample is disclosed.

[0006]

However, the above-mentioned prior art has the following problems.

First, the problems associated with measurement using absorbance analysis will be described. When measuring the concentration of hydrogen peroxide by absorption, it is difficult to prevent the influence of interference substances. Typical interfering substances include impurities such as precipitates such as slurries, titanium compounds, and organic acids, which affect the absorption of hydrogen peroxide and reduce the measurement accuracy. Specifically, the precipitate interferes with the absorption of light, and the titanium compound and the organic acid overlap with the absorption value of hydrogen peroxide.
FIG. 15 shows the light absorption curves of hydrogen peroxide, slurry and hydrogen peroxide added slurry. As shown in the figure, the slurry and hydrogen peroxide have absorption bands in almost the same wavelength region, and it can be seen that it is difficult to quantify hydrogen peroxide in the hydrogen peroxide-added slurry.

Further, the method described in Japanese Patent Laid-Open No. 8-136450 is, as shown in FIG. 10, a pump, a flow cell, a flow path switching valve, a loop, a cooler, a pipe, a defoamer, a mixer, and an ultraviolet absorber. Since a measuring unit and a computer used for data processing are required, the device is complicated, has a large number of parts, and is expensive to manufacture. The above method has room for improvement in this respect.

On the other hand, in the measurement using the hydrogen peroxide quantitative electrode as disclosed in Japanese Utility Model Publication No. 6-43734, impurities contained in the measurement sample react with the electrode member to lower the measurement accuracy, There was a problem of contaminating the electrodes. Further, when hydrogen peroxide is present at a high concentration in the measurement sample, the sensitivity of the electrode is saturated, which makes accurate measurement difficult.

Although the hydrogen peroxide concentration itself is not measured, various biosensors having a structure in which a multilayer film including an immobilized enzyme layer is formed on a hydrogen peroxide quantitative electrode have been developed. This type of sensor is
For example, it is a system in which glucose is converted into hydrogen peroxide by an enzymatic reaction and the produced hydrogen peroxide is quantified. Japanese Laid-Open Patent Publication No. 10-26601 discloses an example of this type of biosensor. The structure of this biosensor is shown in FIG. A hydrogen peroxide electrode 32 is formed on an insulating substrate 31, and a γ-aminopropyltriethoxysilane film 33, an acetyl cellulose film 34, a perfluorocarbon sulfonic acid resin film 35, and an organic substance on which an enzyme having a catalytic function is immobilized. The polymer film 36 and the polyalkylsiloxane film 37 are formed in this order. However, this biosensor still has room for improvement in the following points.

This biosensor has a limited permeation membrane made of polyalkylsiloxane, and by this membrane,
By limiting the permeation of hydrogen peroxide in the solution to the hydrogen peroxide electrode, it is possible to measure even high-concentration hydrogen peroxide of about 1 mM. However, since the limited permeation membrane is not strong enough, the durability was not always sufficient when the electrode was used for a long period of time.

As described above, the present situation is that no hydrogen peroxide concentration measuring technique has been found which has sufficient measurement accuracy, quick response, and excellent stability in repeated measurement.
Therefore, various process problems exist in the fields of semiconductor device manufacturing and food processing. These problems will be specifically described below.

First, problems in manufacturing a semiconductor device will be described.

In manufacturing a semiconductor device, it is necessary to clean the wafer at various stages before or after element formation. So-called RCA cleaning is widely used as a typical technique for cleaning wafers, and a mixed solution of an acid or a base and hydrogen peroxide is usually used as a cleaning solution for the steps included in the RCA cleaning. The acid or base dissolves a part of the silicon substrate,
It plays the role of lifting off particles. On the other hand, hydrogen peroxide plays a role of preventing surface roughness due to excessive progress of dissolution of the silicon substrate. When such a cleaning liquid is used for a long period of time, the hydrogen peroxide concentration in the liquid decreases due to exhaustion of hydrogen peroxide, and as a result, the action of preventing the surface roughness of the substrate decreases. Therefore, in order to continuously use the surface liquid, it is necessary to appropriately supplement the hydrogen peroxide solution to restore the surface roughness preventing ability. Conventionally, a predetermined amount of hydrogen peroxide solution is replenished in the stripping solution at regular time intervals or at a constant number of treatments based on an empirically determined reference with reference to the inspection result of the substrate after cleaning. However, since the degree of deterioration of the cleaning liquid is not always uniform over a certain period of time or a certain number of treatments, the surface roughness preventing ability does not recover sufficiently with repeated replenishment of a fixed amount of hydrogen peroxide water, and the inside of the stripping tank In many cases, the renewal of all liquids had to be done at an early stage. For this reason, the amount of the cleaning liquid used is increased more than necessary, which is one of the causes of increasing the cost. Further, it is difficult to finely replenish the hydrogen peroxide solution, which may cause fluctuations in the cleaning performance of the cleaning liquid.

Strict control of the hydrogen peroxide concentration is also required in the resist stripping process. The photoresist on the semiconductor substrate is usually subjected to an ashing treatment with oxygen plasma, followed by a treatment using SPM (a mixed solution of sulfuric acid and hydrogen peroxide solution) as a stripping solution, and further, an APM (ammonia, Peeling is performed by performing a treatment using a mixed solution of hydrogen peroxide water. These stripping solutions oxidize and decompose the photoresist to strip it from the substrate, but at this time, hydrogen peroxide is consumed and the concentration of hydrogen peroxide in the solution drops, resulting in a rapid drop in stripping ability. A resist residue is generated on the processed substrate. Therefore, in order to continuously use the above-mentioned stripping solution, it is necessary to replenish the hydrogen peroxide solution appropriately to recover the stripping ability. Conventionally, a predetermined amount of hydrogen peroxide solution is replenished to the stripping solution at regular time intervals or at constant processing numbers based on an empirically determined reference with reference to the inspection results of the substrate after stripping. However,
Since the degree of deterioration of the stripping solution for a certain period of time or for a certain number of treatments is not always uniform, the stripping ability will not be sufficiently recovered by repeating the replenishment of a fixed amount of hydrogen peroxide solution, and the total amount of all solutions in the stripping tank will not be recovered. In many cases, the update had to be done early. For this reason, the amount of the stripping solution used becomes unnecessarily large, which is one of the causes of cost increase.
Further, it is difficult to finely replenish the hydrogen peroxide solution, which may cause variations in the stripping performance of the stripping solution. Furthermore, strict control of the hydrogen peroxide concentration is also required in the chemical mechanical polishing (CMP) process. CMP is a technique for flattening a bare wafer or a wafer on which a silicon oxide film is formed. It is basic to use solid abrasive grains and a polishing liquid containing an oxidizing substance as the main component, and to oxidize the surface of the object to be polished by the oxidizing action of the oxidizing substance while mechanically removing the oxide by the solid abrasive grains. CMP mechanism. The oxidizing substance usually contains hydrogen peroxide (H2O2) as an essential component. In addition to this, ferric nitrate (Fe (NO
₃ ) ₃ ) etc. are added as appropriate. Since the polishing rate and polishing accuracy in CMP vary greatly due to subtle differences in the composition of the polishing liquid, the CMP polishing liquid must always be controlled and managed to have an optimum composition. However, conventional CM
In P, it was difficult to measure the hydrogen peroxide concentration with sufficient accuracy, so it was not easy to realize the strict control of the polishing liquid as described above, and the composition of the polishing liquid changed with time. However, there is a problem in that the performance of the polishing liquid, and thus the polishing rate, fluctuates.

Further, for example, in metal CMP for forming copper wiring, it is known that problems such as dicing and erosion occur due to the difference in polishing rate between the copper film, the barrier metal film and the interlayer insulating film. In order to solve these problems, the composition of the polishing liquid is optimally designed, and further, several kinds of polishing liquids having different compositions are used together at each stage of CMP. That is, CM
The composition of the P polishing liquid is highly controlled so that the polishing rate becomes appropriate according to the type of the film to be polished. Therefore, even if the composition of the polishing liquid slightly changes, the polishing rate for each of the copper film, the barrier metal film, and the interlayer insulating film changes, and the effect of preventing dicing and erosion is lost. When the dishing or erosion becomes remarkable, various problems such as a decrease in electromigration resistance, an increase in contact resistance of the interlayer connection plug, and a deterioration in flatness of the wiring structure are caused. From the above, Metal CM
In P, it is particularly important to keep the composition of the polishing liquid constant.

As described above, in wafer cleaning, resist stripping, and CMP processes in the manufacture of semiconductor devices, it is a particularly important technical problem to control and manage the chemical solution to be used with high accuracy. Various studies have been conducted to maintain a constant composition or chemical performance. However, regarding the measurement of hydrogen peroxide concentration, at present, no high-level measurement technique has been found that achieves the above-mentioned object, and a technique for measuring the hydrogen peroxide concentration quickly, accurately, and stably. Was strongly demanded. In addition, regarding the use of the resist stripping solution and the cleaning solution, the processing temperature should be 5
In many cases, the temperature is 0 ° C. or higher, and stability of measurement at high temperature is also required. In conventional electrochemical measurement using a hydrogen peroxide quantitative electrode, sufficient stability at high temperature was not obtained, and there was room for improvement in this respect as well.

The problems in the process of manufacturing the semiconductor device have been described above. However, also in the field of food manufacturing, there has been a demand for improvement in measurement accuracy and measurement stability. A chemical solution containing hydrogen peroxide is used in the disinfection process and the sterilization process of food production. It is necessary to strictly control and manage the hydrogen peroxide concentration in this chemical solution. However, since proteins and the like contained in food easily adhere to the electrodes, the measurement accuracy may be lowered, and the sensitivity may be remarkably lowered particularly during long-term use. Further, in the prior art, a restricted permeation membrane showing good restricted permeability has not been found, and therefore, it is difficult to obtain a sufficiently wide measurement range, and particularly high concentration hydrogen peroxide is measured. Was difficult.

The present invention has been made in view of the above circumstances, and has high measurement accuracy, good responsiveness, durability for long-term use, and high-temperature stability, and under a wide range of use conditions. An object is to provide a measurable hydrogen peroxide electrode, a sensor using the same, and a measuring instrument.

[0020]

According to the present invention for solving the above problems, there is provided an electrode provided on an insulating substrate, and a limited transmission layer covering at least a part of the electrode. Provides a hydrogen peroxide electrode, which is mainly composed of a polymer in which a pendant group containing at least a fluoroalkylene block is bonded to a vinyl polymer containing no fluorine.

That is, the hydrogen peroxide electrode of the present invention comprises an electrode (electrode layer) provided on an insulating substrate and a plurality of layers provided on the electrode and having various functions.
The limited transmission layer is formed so as to cover at least a part of the electrode, but it is desirable that the limited transmission layer covers a large area of the electrode. The shape of the electrode is usually such that the upper surface has a larger area than the side surface as shown in FIG. 1. In this case, it is desirable to form the limited permeation layer at least on the upper part of the electrode.

The hydrogen peroxide electrode of the present invention detects and quantifies the hydrogen peroxide concentration by measuring the oxidation current flowing when hydrogen peroxide reaches the surface of the electrode (electrode layer). The limited permeation layer serves to limit the amount of hydrogen peroxide reaching the electrode surface. In the electrode of the present invention, since the limited permeation layer is composed of the polymer having the above-mentioned specific structure, good limited permeation is obtained, and it becomes possible to measure high concentration hydrogen peroxide, and the measurement range is expanded. To do.

The polymer constituting the above-mentioned restricted permeation layer is a fluoroalkylene block (fluoroalkylene unit).
It has a pendant group containing For this reason, adhesion of contaminants such as slurry and organic acids is suppressed, and a hydrogen peroxide electrode exhibiting stable output characteristics even when used for a long period of time can be obtained. Further, since fluoroalkylene does not dissolve in most non-fluorine-based solvents and detergents such as surfactants, a hydrogen peroxide electrode having good chemical resistance can be obtained. Furthermore, even under a temperature of about 100 ° C., stable measurement is possible without damaging the electrodes.

Since this polymer has a fluorine-free vinyl polymer as the main chain, it has good adhesion to other organic polymer layers. Therefore, no gap is generated between the electrode surface and the limited permeation layer. Therefore, it is possible to speed up the response speed and shorten the time required for cleaning. Further, since the adhesion is good, the durability of the layer structure is improved, and a hydrogen peroxide electrode that can withstand a temperature of about 100 ° C. and is not easily damaged even when used for a long period of time can be obtained. Here, in addition to the pendant group containing the fluoroalkylene block, other suitable side chains and functional groups may be bonded. For example, by having a functional group having an appropriate polarity such as —OH group or —COOH group, the adhesion with the electrode or another organic polymer layer can be further enhanced.

Further, since the polymer constituting the restricted permeation layer has a unique structure in which a pendant group containing at least a fluoroalkylene block is bonded to a vinyl polymer containing no fluorine, a high concentration of the polymer is obtained. Hydrogen peroxide can be directly measured without dilution, and the range of measurement concentration can be greatly expanded. Further, since the limited permeation property is good, the layer thickness of the limited permeation layer can be reduced, and for example, the layer thickness can be set to 0.1 μm or less. Therefore, the response speed can be increased and the time required for cleaning can be shortened. The limited permeation layer is capable of producing a uniform thin film by a simple process such as a dipping method, a spin coating method, or a spraying method, and is excellent in mass productivity.

Further, according to the present invention, there is provided an electrode provided on an insulating substrate, and a limited permeation layer covering at least a part of the electrode, and the limited permeation layer comprises fluorocarbon of polycarboxylic acid (A). Provided is a hydrogen peroxide electrode, which is mainly composed of alcohol ester.

Further, according to the present invention, there is provided an electrode provided on an insulating substrate, and a restricted permeation layer covering at least a part of the electrode, and the restricted permeation layer is a fluorocarbon of polycarboxylic acid (A). A hydrogen peroxide electrode comprising an alcohol ester and an alkyl alcohol ester of polycarboxylic acid (B) is provided.

Further, according to the present invention, there is provided an electrode provided on an insulating substrate, and a restricted permeation layer covering at least a part of the electrode, the restricted permeation layer comprising an alkyl alcohol ester group and a fluoroalcohol ester. Provided is a hydrogen peroxide electrode, which is mainly composed of a polycarboxylic acid ester compound having a group.

These hydrogen peroxide electrodes are composed of an electrode (electrode layer) provided on an insulating substrate and a plurality of layers provided on the electrode and having various functions. The limited transmission layer is formed so as to cover at least a part of the electrode,
Desirably, the limited permeation layer covers a large area of the electrode. The shape of the electrode is usually such that the upper surface has a larger area than the side surface as shown in FIG. 1. In this case, it is desirable to form the limited permeation layer at least on the upper part of the electrode.

The hydrogen peroxide electrode of the present invention detects and quantifies the hydrogen peroxide concentration by measuring the oxidation current flowing when hydrogen peroxide reaches the surface of the electrode (electrode layer). The limited permeation layer serves to limit the amount of hydrogen peroxide reaching the electrode surface. In the electrode of the present invention, since the restricted permeation layer is composed of the polymer having the specific structure as described above, good restricted permeation is obtained, and it becomes possible to measure high concentration hydrogen peroxide, and the measurement range is expanded. To do.

The hydrogen peroxide electrode uses a fluoroalcohol ester of polycarboxylic acid as a constituent material of the restricted permeation layer. Here, the fluoroalcohol ester of polycarboxylic acid is an ester of a part or all of the carboxyl groups of polycarboxylic acid esterified with fluoroalcohol. Fluoroalcohol is one in which all or at least one of the hydrogen atoms in the alcohol is replaced with fluorine.

Since the constituent material of the restricted permeation layer has a fluoroalcohol ester group, adhesion of contaminants such as slurry and organic acid is suppressed, and a hydrogen peroxide electrode exhibiting stable output characteristics even when used for a long period of time. Is obtained. Also, since the fluoroalcohol ester group does not dissolve in most non-fluorine-based solvents and detergents such as surfactants,
A hydrogen peroxide electrode with good chemical resistance can be obtained. further,
Even under a temperature condition of about 100 ° C., a hydrogen peroxide electrode showing a stable output can be obtained without being damaged.

These hydrogen peroxide electrodes use a polymer having a polycarboxylic acid main chain in the restricted permeation layer. Further, fluoroalcohol is bound to this main chain through an ester group. Good adhesion with electrodes,
No gap is formed between the limited permeation layer formed on the electrode surface. Therefore, it is possible to speed up the response speed and shorten the time required for cleaning. Moreover, since the adhesion is good, the durability of the layer structure is improved, and a hydrogen peroxide electrode that is less likely to be damaged even when used for a long period of time can be obtained. Here, an appropriate functional group other than the fluoroalcohol ester group may be bonded to the main chain composed of the polycarboxylic acid. By having a functional group having an appropriate polarity, it is possible to further improve the adhesiveness to another organic polymer layer such as an adjacent immobilized enzyme layer.

Further, the polymer constituting the restricted permeation layer has a unique structure in which a part or all of the carboxyl groups of polycarboxylic acid are esterified with fluoroalcohol, and therefore, for example, a hydrogen peroxide sensor or the like. When used for, it is possible to greatly expand the measurement concentration range. In addition, since the limited permeability is good, it is possible to reduce the layer thickness of the limited permeability layer. For example, the layer thickness can be 0.1 μm or less. Therefore, the response speed can be increased and the time required for cleaning can be shortened.

The limited permeation layer is capable of producing a uniform thin film by a simple process such as a dipping method, a spin coating method and a spraying method, and is excellent in mass productivity.

The restricted permeation layer comprises (i) a fluoroalcohol ester of polycarboxylic acid (A) and an alkyl alcohol ester of polycarboxylic acid (B), or (ii) an alkyl alcohol ester group. In addition to the effects described above, the advantage that the stability at high temperature becomes good is obtained when the structure is mainly composed of a polycarboxylic acid ester compound having a fluoroalcohol ester group. The hydrogen peroxide electrode may be stored and used at a relatively high temperature (for example, about 60 ° C.). The hydrogen peroxide electrode provided with the limited permeation layer having the above structure has excellent stability because the measurement sensitivity hardly changes even when it is left at high temperature.

In the hydrogen peroxide electrode of the present invention described above, the electrode and the restricted permeation layer may be formed so as to be in direct contact with each other, or another layer may be interposed therebetween. For example, a structure having a bonding layer mainly composed of a silane coupling agent between the electrode and the limited permeation layer,
An ion exchange resin layer mainly composed of an ion exchange resin having a perfluorocarbon skeleton may be provided between the bonding layer and the restricted permeation layer. Similarly, other layers may be interposed between them.

The hydrogen peroxide electrode of the present invention is for directly quantifying hydrogen peroxide contained in a measurement sample,
It is different from the enzyme electrode used in biosensors and the like. The enzyme electrode is for quantifying the concentration of a measurement target component such as glucose by converting a measurement target component such as glucose into hydrogen peroxide by an enzyme and quantifying the hydrogen peroxide. The hydrogen peroxide electrode of the present invention is
It differs from such an enzyme electrode in the following points. (i) The enzyme electrode targets a specific component such as glucose in a measurement sample as a measurement target, whereas the hydrogen peroxide electrode of the present invention targets hydrogen peroxide in a measurement sample. (ii) In the enzyme electrode, the layer containing the above enzyme is essential, but in the hydrogen peroxide electrode of the present invention, the layer containing such enzyme is not necessary, but rather becomes a factor that lowers the measurement sensitivity and responsiveness. Therefore, it is preferable not to have such a layer.

Further, according to the present invention, there is provided a hydrogen peroxide sensor using the above hydrogen peroxide electrode as a working electrode. Since this hydrogen peroxide sensor has a limited permeation layer made of a polymer having the above-mentioned unique structure on the surface of the hydrogen peroxide electrode, it has excellent measurement accuracy, responsiveness, high-temperature stability and long-term use stability, and can be used in a wide range. It can be used under measurement conditions.

Further, according to the present invention, various measuring instruments using the above hydrogen peroxide sensor are provided. That is, according to the present invention, there is provided a measuring instrument comprising the hydrogen peroxide sensor and a data notifying unit for notifying an electric signal obtained from the hydrogen peroxide sensor.

Further, the hydrogen peroxide sensor, and an electrochemical measurement circuit section for obtaining an electric signal from the hydrogen peroxide sensor,
A data processing unit that calculates a measurement value based on the electric signal,
There is provided a measuring instrument comprising: a data notifying unit for notifying the measured value. These instruments are
Since it has a hydrogen peroxide sensor having a working electrode of a specific structure, it is excellent in high-temperature stability and long-term stability and can be used under a wide range of measurement conditions. Moreover, the operation method is simple, and even a person unfamiliar with the device can easily handle it.

According to the present invention, the step of forming an electrode on an insulating substrate, and at least a fluoroalkylene block is added to the fluorine-free vinyl polymer directly on the electrode or through another layer. After applying a liquid containing a polymer having a pendant group contained therein, it is dried,
And a step of forming a limited permeation layer.

In this method for producing a hydrogen peroxide electrode, the limited permeation layer is formed by applying and drying a liquid containing a polymer having the above-mentioned specific structure. Therefore, stability during repeated measurement, adhesion with adjacent layers, durability,
It is possible to form a limited permeation layer having excellent limited permeation properties and the like with good film thickness controllability. Further, since the above liquid has a low viscosity, the limited permeation layer can be easily formed with a thin film thickness. Specifically, 0.01 to 3 μm after drying
The limited permeation layer can be formed well.

[0044]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the "hydrogen peroxide electrode" is an electrode for measuring the concentration of hydrogen peroxide in a sample, and has a constitution in which a limited permeation layer is provided on the electrode. Say something. The “hydrogen peroxide sensor” refers to an element portion including the hydrogen peroxide electrode, and includes a counter electrode and a reference electrode as necessary. Further, the "measuring device" in the present invention means a system including the above hydrogen peroxide sensor, and means one provided with various means for notifying and processing an electric signal obtained from the hydrogen peroxide sensor.
Hereinafter, the hydrogen peroxide electrode, the hydrogen peroxide sensor, and the measuring device according to the present invention will be described in detail. The hydrogen peroxide electrode of the present invention is used to determine the presence or absence of hydrogen peroxide in a measurement target and to quantify the hydrogen peroxide concentration in the measurement target. Especially effective for. This is because the hydrogen peroxide electrode of the present invention has high measurement sensitivity and a wide measurement range.

The first hydrogen peroxide electrode according to the present invention has an electrode provided on an insulating substrate and a limiting permeation layer covering at least a part of the electrode, and the limiting permeation layer contains fluorine. It is characterized by being mainly composed of a polymer in which a pendant group containing at least a fluoroalkylene block is bonded to a vinyl-based polymer not containing it.

The term "predominantly" means that the above-mentioned polymer is a main component constituting the restricted permeation layer. For example, the content of the above-mentioned polymer in the restricted permeation layer is 5.
It means 0 mass% or more.

Here, the "vinyl-free polymer containing no fluorine" is a part having a role of improving the adhesion to the electrode, and therefore, the structure is not particularly limited, but it does not contain fluorine. Don't If fluorine is contained in the polymer portion excluding the pendant group, the adhesion to the electrode and other organic polymer layers is reduced, it becomes difficult to prepare a solution, and it becomes difficult to form the limited permeation layer as a thin film.

The fluorine-free vinyl polymer is a polymer having a main skeleton composed of carbon-carbon bonds, and preferred examples thereof include unsaturated hydrocarbons, unsaturated carboxylic acids,
And homopolymers or copolymers of one or more monomers selected from the group consisting of unsaturated alcohols. Of these, polycarboxylic acids are particularly preferable. By selecting such a polymer, the adhesion with the electrode or another organic polymer layer becomes particularly good, and a limited permeation layer having excellent durability can be obtained. Further, it is preferable that the fluoroalkylene block is bonded to the vinyl polymer via an ester group. Since the ester group has an appropriate polarity, the adhesion with the electrode and other organic polymer layers is further improved. As an example, polymethacrylic acid 1H, 1
H-perfluorooctyl and polyacrylic acid 1H, 1
H, 2H, 2H-perfluorodecyl etc. are mentioned. The pendant group containing a fluoroalkylene block refers to a pendant group containing fluoroalkylene as a constituent unit. Fluoroalkylene refers to an alkylene group in which some or all of the hydrogen atoms are replaced with fluorine. X / (x +) where x is the number of fluorine atoms contained in the pendant group, and y is the number of hydrogen atoms contained in the pendant group.
The value of y) is preferably 0.3 to 1, and more preferably 0.8 to 1. By doing so, adhesion of contaminants to the restricted permeation layer is suppressed, and good restricted permeability is obtained. The pendant group preferably has 3 to 15 carbon atoms, more preferably 5 to 10 carbon atoms, and most preferably 8 to 10 carbon atoms. By doing so, the length of the pendant group becomes appropriate, good film-forming properties and limited permeability can be obtained, and good adhesion with the electrode and the adjacent polymer layer is also maintained.

The bonding rate of the pendant group to the vinyl polymer, that is, the content of the pendant group is not particularly limited, and can be set to an appropriate value according to other polymer layer materials and applications. For example, it is 0.1 to 30%. By setting the content ratio of the pendant group having water repellency to an appropriate range as described above, good restricted permeability and good adhesion to the electrode and the adjacent polymer layer can be obtained. Here, the bond ratio of the pendant group means the ratio of the pendant group to all the groups bonded to the carbon-carbon bond which is the main skeleton of the vinyl polymer. For example, the vinyl-based polymer serving as the main chain is polyacrylic acid, and the number of -COOH groups is 1
When 0% is esterified to become a pendant group, the bond rate of -COOH group is 25% and the esterification rate is 10%.
2.5% obtained by multiplying by is the pendant group bonding rate.

The molecular weight of the polymer constituting the restricted permeation layer is preferably 1,000 to 50,000, more preferably 3,000 to 30,000. If the molecular weight is too large, it becomes difficult to adjust the solution, and it becomes difficult to make the limiting permeation layer thin. If the molecular weight is too small, sufficient limiting permeability cannot be obtained. The molecular weight referred to here is the number average molecular weight, and can be measured by GPC (gel permeation chromatography), for example.

The second hydrogen peroxide electrode according to the present invention has an electrode provided on an insulating substrate and a limiting permeation layer covering at least a part of the electrode, and the limiting permeation layer is made of polycarboxylic acid. It is mainly composed of a fluoroalcohol ester of acid (A). The term “mainly comprises” means that the above-mentioned polymer is a main component constituting the restricted permeation layer, and for example, the content of the above-mentioned polymer in the restricted permeation layer is 50% by mass or more.

The third hydrogen peroxide electrode according to the present invention has an electrode provided on an insulating substrate and a limiting permeation layer covering at least a part of the electrode. A fluoroalcohol ester of polycarboxylic acid (A),
It is characterized by comprising an alkyl alcohol ester of polycarboxylic acid (B).

The fourth hydrogen peroxide electrode according to the present invention has an electrode provided on an insulating substrate and a limiting permeation layer covering at least a part of the electrode, and the limiting permeation layer is It is mainly composed of a polycarboxylic acid ester compound having an alkyl alcohol ester group and a fluoroalcohol ester group. The term “mainly comprises” means that the above-mentioned polymer is a main component constituting the restricted permeation layer, and for example, the content of the above-mentioned polymer in the restricted permeation layer is 50% by mass or more.

The polycarboxylic acid (A), (B) and the polycarboxylic acid constituting the above polycarboxylic acid ester compound are polymers having a structural unit of carboxylic acid such as acrylic acid, methacrylic acid, fumaric acid and itaconic acid. Say. Examples thereof include polymethacrylic acid, polyacrylic acid, and copolymers thereof. The polycarboxylic acid (A) and the polycarboxylic acid (B) may be the same or different.

When the number of fluorine atoms contained in the fluoroalcohol ester group is x and the number of hydrogen atoms is y, x
The fluorine content of the fluoroalcohol ester group represented by / (x + y) is preferably 0.3 to 1, and more preferably 0.8 to 1. By doing so, adhesion of contaminants to the restricted permeation layer is suppressed, and good restricted permeability is obtained.

The fluoroalcohol constituting the fluoroalcohol ester preferably has 3 to 15 carbon atoms, more preferably 5 to 10 carbon atoms, and most preferably 8 to 10 carbon atoms.
And By doing so, the length of the pendant group becomes appropriate, good film-forming properties and limited permeability can be obtained, and good adhesion with the electrode and the adjacent polymer layer is also maintained. The esterification rate of the fluoroalcohol ester of polycarboxylic acid is not particularly limited, and can be set to an appropriate value according to other polymer layer materials and applications. For example,
0.1 to 30%. The esterification rate refers to the rate at which the carboxyl group of the main chain polyacrylic acid is esterified. By setting the esterification rate in the above range,
The content of the fluoroalcohol ester group having water repellency becomes appropriate, and good restricted permeability and good adhesion to the electrode and the adjacent polymer layer can be obtained.

In the present invention, the fluoroalcohol constituting the fluoroalcohol ester is preferably a primary alcohol. This is because the adhesion of contaminants to the limited permeation layer is effectively suppressed, and high chemical resistance to acids, alkalis and various organic solvents can be obtained. For example, polymethacrylic acid 1H, 1H-perfluorooctyl and polyacrylic acid 1H, 1H, 2H, 2H-
Perfluorodecyl can be preferably used.

The restricted permeation layer comprises a fluoroalcohol ester of polycarboxylic acid (A) and an alkyl alcohol ester of polycarboxylic acid (B), or has an alkyl alcohol ester group and a fluoroalcohol ester group. When it is mainly composed of a polycarboxylic acid ester compound, a hydrogen peroxide electrode having good high temperature stability can be obtained.

The preferable form of the "fluoroalcohol ester" is as described above.

The alkyl alcohol of the alkyl alcohol ester portion means a chain or cyclic alcohol represented by C _n H _{n + 2} OH- (n is a natural number). n is an integer of 1 or more, preferably 2 to 10, more preferably 4 to 8, and most preferably 6. For example, a hexyl group and a cyclohexyl group are preferably used. By doing so, the stability becomes even better when the hydrogen peroxide electrode is left under high temperature.

When the restricted permeation layer comprises a fluoroalcohol ester of polycarboxylic acid (A) and an alkyl alcohol ester of polycarboxylic acid (B), the polycarboxylic acid (A) for the restricted permeation layer The content of the fluoroalcohol ester is preferably 50 to
The amount is 99% by mass, more preferably 75 to 99% by mass, and most preferably 80 to 95% by mass. If the content is too low, the durability of the restricted permeation layer may decrease. If the content is too high, it may not be possible to obtain sufficient stability when left at high temperature. On the other hand, the content of the alkyl alcohol ester of the polycarboxylic acid (B) in the restricted permeation layer is preferably 1 to 50% by mass, more preferably 1 to 2%.
5% by mass, most preferably 5 to 20% by mass. If the content is too low, the stability when left at high temperature may not be sufficiently obtained. Further, if the content is too high, the durability of the limited permeation layer may decrease. The alkyl alcohol ester of polycarboxylic acid (B) is obtained by esterifying at least a part of the polycarboxylic acid (B) with the alkyl alcohol, and a preferable example thereof is polycyclohexyl methacrylate. .

When the restricted permeation layer is constituted by using a polycarboxylic acid ester compound having an alkyl alcohol ester group and a fluoroalcohol ester group, the preferable form of each ester group is as described above, and various combinations thereof are available. Things can be adopted. The ratio of the alkyl alcohol ester group to the fluoro alcohol ester group is not particularly limited, but a / is the number of the fluoro alcohol ester group in the above ester compound is a and the number of the alkyl alcohol ester group is b.
The value of b is preferably 50/50 to 99/1, more preferably 75/25 to 99/1, most preferably 80/2.
0 to 95/5.

Examples of such polycarboxylic acid ester compounds include compounds having a repeating unit represented by the following formula (1). When the COO-R group is polycyclohexyl methacrylate, the high temperature stability is particularly good. Also, the limited permeability becomes good.

[0064]

[Chemical 1] (N is an integer of 2 or more, X is an integer of 0 or more, and Y is an integer of 1 or more.) As such a compound, a copolymer of 1H, 1H-perfluorooctyl methacrylate and cyclohexyl methacrylate, or , Acrylic acid 1H, 1H, 2H, 2H
Examples thereof include a copolymer of perfluorodecyl and cyclohexyl methacrylate. For example, a compound having a repeating unit of 1H, 1H, 2H, 2H-perfluorodecyl acrylate and cyclohexyl methacrylate as represented by the following formula (2) is preferably used.

[0065]

[Chemical 2] (N represents an integer of 2 or more.) When the above copolymer is used, the high temperature stability is particularly good, and other properties such as the restricted permeability layer are also good.

As described above, the restricted permeation layer of the hydrogen peroxide electrode of the present invention is composed of a polymer having a specific structure, but may be composed of a mixture of two or more kinds of polymers having different structures or molecular weights. .

In the hydrogen peroxide electrode described above, the molecular weight of the polycarboxylic acid ester compound having a fluoroalcohol ester and an alkyl alcohol ester group and a fluoroalcohol ester group of the polycarboxylic acid (A) constituting the restricted permeation layer is preferably Is 1000 ~
It is 50,000, and more preferably 3000 to 30,000. If the molecular weight is too large, it will be difficult to adjust the solution,
It may be difficult to reduce the thickness of the limited permeation layer. If the molecular weight is too small, sufficient limiting permeability may not be obtained. The molecular weight referred to here is the number average molecular weight.

In the hydrogen peroxide electrode described above, the thickness of the restricted permeation layer is preferably 0.01 to 3 μm, more preferably 0.01 to 1 μm, and most preferably 0.01.
˜0.1 μm. With such a thickness, the response speed can be improved and the cleaning time can be shortened.

An example of the sensor for quantifying hydrogen peroxide of the present invention is shown in FIG. In this example, a hydrogen peroxide electrode is used as the working electrode 7, and a counter electrode 8 and a reference electrode 9 are further provided on the quartz substrate. The working electrode 7 and the counter electrode 8 are platinum electrodes, and the reference electrode 9 is a silver / silver chloride electrode. On the working electrode 7, a bonding layer 4 containing γ-aminopropyltriethoxysilane as a main component and a limiting permeation layer 3 made of a fluoroalcohol ester layer of methacrylic acid resin are sequentially formed. The working electrode 7, the counter electrode 8, and the reference electrode 9 are electrically connected to the measurement system.

In the above hydrogen peroxide sensor, the working electrode, the counter electrode and the reference electrode are provided on the same insulating substrate 1, but they may be formed on different substrates. An example of such a hydrogen peroxide sensor is shown in FIGS. Figure 5
In the hydrogen peroxide sensor, the working electrode 7, the counter electrode 8 and the reference electrode 9 are formed on different insulating substrates 1.
On the working electrode 7, a bonding layer 4 containing γ-aminopropyltriethoxysilane as a main component and a limited permeation layer 3 made of a fluoroalcohol ester layer of methacrylic acid resin are sequentially formed. In the hydrogen peroxide sensor of FIG. 6, the working electrode 7 and the counter electrode 8 are formed on the same insulating substrate 1, and the reference electrode 9 is formed on the other insulating substrate 1. On the working electrode 7 and the counter electrode 8, a binding layer 4 containing γ-aminopropyltriethoxysilane as a main component and a restricted permeation layer 3 made of a fluoroalcohol ester layer of methacrylic acid resin are sequentially formed. Although an example of an amperometric type sensor is shown in the drawing, it goes without saying that the hydrogen peroxide electrode of the present invention can also be applied to an ion sensitive field effect transistor type sensor.

The hydrogen peroxide sensor according to the present invention has high measurement accuracy, good responsiveness, good durability for long-term use, and can be measured under a wide range of use conditions. It is preferably used in various applications where such performance is required. For example, wafer cleaning liquid, resist stripping liquid, C
It can be preferably used for controlling and managing the composition of a chemical liquid such as an MP polishing liquid. When used for these purposes, the hydrogen peroxide concentration can be measured with unprecedentedly high precision and quick response, so that the required hydrogen peroxide can be quickly and accurately replenished. . Therefore, as compared with the conventional technology, it becomes possible to maintain the chemical composition and the chemical performance at a considerably excellent accuracy, and cleaning of each batch when a plurality of wafers are processed, resist stripping or polishing. The variation can be effectively reduced. Moreover, since the frequency of total exchange of the chemical liquid can be reduced, the chemical liquid cost can be significantly reduced. In particular, when it is used for controlling and managing the composition of a CMP polishing liquid, phenomena such as dishing and erosion can be stably prevented, and variation between batches related to these phenomena can be effectively reduced. Furthermore, when used as a resist stripping solution or a wafer cleaning solution, the temperature range where these chemicals are normally used,
For example, there is an advantage that stable measurement can be performed even in a temperature range of 40 ° C. or higher. This is because the sensor of the present invention can stably measure at high temperature.

The measuring instrument of the present invention is preferably provided with a hydrogen peroxide sensor detachably. This is because it is desirable to have a structure that can be easily replaced when the hydrogen peroxide electrode is damaged or damaged. Here, in addition to the form in which only the part of the hydrogen peroxide sensor is removable, the wiring connecting the hydrogen peroxide sensor and other parts and the part including the hydrogen peroxide sensor are also removable. It may be in the form. For example, in the measuring instrument having the configuration shown in FIG. 7A, the wiring 14 between the hydrogen peroxide sensor 10 and the electrochemical measurement circuit section 11 may be detachable.
The portion including the hydrogen peroxide sensor 10, the wiring 14, and the electrochemical measurement circuit unit 11 may be detachable. The data processing unit in the measuring instrument of the present invention has a function of calculating a measurement value based on an electric signal obtained from the hydrogen peroxide sensor. For example, the electric signal is an analog signal and / or a digital signal. It operates by converting to and calculating the measured value.

The method for producing a hydrogen peroxide electrode of the present invention comprises a step of forming an electrode on an insulating substrate, and a vinyl polymer containing no fluorine, directly on the electrode or through another layer. And applying a liquid containing a polymer having at least a fluoroalkylene block-containing pendant group bonded thereto, followed by drying to form a restricted permeation layer. Regarding preferred embodiments of the "polymer in which a pendant group containing at least a fluoroalkylene block is bonded to a vinyl polymer containing no fluorine", the first to fourth hydrogen peroxide electrodes according to the present invention are described. It is the same as described in the description part, and examples thereof include fluoroalcohol esters of polycarboxylic acids, and polymethacrylic acid 1H, 1H-
Perfluorooctyl, polyacrylic acid 1H, 1H, 2
H, 2H-perfluorodecyl or a copolymer of 1H, 1H-perfluorooctyl methacrylate and cyclohexyl methacrylate, 1H, 1H, 2 acrylate
Examples thereof include copolymers of H, 2H-perfluorodecyl and cyclohexyl methacrylate.

Embodiments of the present invention will be further described below with reference to the drawings.

(First Embodiment) This embodiment will be described with reference to FIG. In the hydrogen peroxide electrode of this embodiment, an electrode 2 functioning as a working electrode is provided on an insulating substrate 1, and a limited permeation layer 3 made of a fluoroalcohol ester layer of methacrylic acid resin is sequentially formed on the electrode 2. ing.

As the material of the insulating base material 1, a material mainly made of a material having a high insulating property such as ceramics, glass, quartz, or plastic can be used. water resistant,
It is preferable that the material has excellent heat resistance, chemical resistance, and adhesion to the electrode.

The material of the electrode 2 is, for example, platinum,
Those mainly composed of gold, silver, carbon and the like can be used, and of these, platinum, which is excellent in chemical resistance and hydrogen peroxide detection characteristics, is preferably used. The electrode 2 on the insulating base material 1 is formed by a sputtering method, an ion plating method, a vacuum deposition method, a chemical vapor deposition method,
It can be formed by an electrolytic method or the like, of which the sputtering method is preferable. This is because the adhesion with the insulating base material 1 is good and the platinum layer can be easily formed. In order to improve the adhesion between the insulating base material 1 and the electrode 2,
A titanium layer, a chromium layer, or the like may be sandwiched between them.

The fluoroalcohol ester of the methacrylic acid resin constituting the restricted permeation layer 3 is a part or the whole of the methacrylic acid resin esterified with fluoroalcohol, and the fluoroalcohol means all of hydrogen in the alcohol, or At least one of them is replaced with fluorine. For example, polymethacrylic acid 1H, 1H
-Perfluorooctyl or polyacrylic acid 1H, 1H,
2H, 2H-perfluorodecyl can be used. In the present invention, for example, polymethacrylic acid 1H, 1H-perfluorooctyl means a polymer in which a part or all of methacrylic acid is esterified with 1H, 1H-perfluorooctyl alcohol.

For the restricted permeation layer 3, a solution of fluoroalcohol ester of methacrylic acid resin diluted with a solvent of perfluorocarbon such as perfluorohexane is used for the electrode 2.
It can be formed by a spin coating method by dropping onto the surface.

The concentration of the methacrylic acid resin fluoroalcohol ester in the solution depends on the substance to be measured, but is 0.1.
The amount is preferably -5% by mass, more preferably about 0.3% by mass. This is because when the content is within this range, good restricted permeability is exhibited.

Regarding the method of forming the restricted transmission layer 3,
There is no limitation as long as it is a method capable of obtaining a layer having a uniform thickness, and a spray coating method, a dipping method, or the like can be used in addition to the spin coating method.

When the hydrogen peroxide electrode of this embodiment is used as a constituent member of a hydrogen peroxide sensor, the outermost layer, the permeation limiting layer 3, limits the diffusion rate of hydrogen peroxide, and hydrogen peroxide reaches the electrode 2. The concentration of hydrogen peroxide can be known by measuring the oxidation current at the time. For the electrode system during measurement, an existing reference electrode is externally used in the case of the two-pole method, and both the counter electrode and the reference electrode are simultaneously immersed in the measurement solution in the case of the three-pole method.

(Second Embodiment) Next, the present embodiment will be described with reference to FIG. The hydrogen peroxide electrode of this embodiment is an electrode 2 that functions as a working electrode on an insulating substrate 1.
And a bonding layer 4 mainly made of γ-aminopropyltriethoxysilane is formed thereon. Further, the limited permeation layer 3 composed of a fluoroalcohol ester layer of methacrylic acid resin is sequentially formed thereon.

The bonding layer 4 formed on the electrode 2 improves the adhesion (bonding force) between the limited permeation layer 3 thereon and the insulating base material 1 and the electrode 2. It also has the effect of improving the wettability of the surface of the insulating base material 1 and improving the uniformity of the film thickness of the limited permeation layer 3. The bonding layer 4 is mainly composed of a silane coupling agent. Examples of the type of silane coupling agent include aminosilane, vinylsilane, and epoxysilane. Of these, γ-aminopropyltriethoxysilane, which is one type of aminosilane, is preferable from the viewpoint of adhesion and selective permeability. The bonding layer 4 can be formed by, for example, spin coating a silane coupling agent solution. At this time, the concentration of the silane coupling agent is preferably about 1 v / v% (volume / volume%). This is because sufficient adhesion can be obtained at this concentration.

(Third Embodiment) Next, the present embodiment will be described with reference to FIG. The hydrogen peroxide electrode of this embodiment is an electrode 2 that functions as a working electrode on an insulating substrate 1.
And a bonding layer 4 mainly made of γ-aminopropyltriethoxysilane is formed thereon. Then, an ion exchange resin layer 5 containing a perfluorocarbon sulfonic acid resin (Nafion) as a main component and a restricted permeation layer 3 including a fluoroalcohol ester layer of a methacrylic acid resin are sequentially formed thereon.

The ion-exchange resin layer 6 containing a perfluorocarbon sulfonic acid resin (Nafion) as a main component was prepared by dissolving perfluorocarbon sulfonic acid resin in ethanol diluted to 50% with pure water to obtain γ-aminopropyltriethoxy. It is dropped on the bonding layer 3 made of silane and formed by spin coating. As the solvent, alcohols such as isopropyl alcohol and ethyl alcohol are used. The concentration of the dropped perfluorocarbon sulfonic acid resin is preferably 1 to 10 w / v%, more preferably 5 to 7 w / v%. This is because the effect of eliminating the influence of the substance interfering with the electrode reaction of hydrogen peroxide becomes remarkable by setting the content in such a range.

(Fourth Embodiment) Next, the present embodiment will be described with reference to the drawings. In the hydrogen peroxide electrode of this embodiment, as shown in FIG. 4, a working electrode 7, a counter electrode 8 and a reference electrode 9 are provided on an insulating substrate 1, and a bond mainly composed of γ-aminopropyltriethoxysilane is provided thereon. Layer 4 has been formed. Further, the limited permeation layer 3 composed of a fluoroalcohol ester layer of methacrylic acid resin is sequentially formed thereon. The materials of the working electrode 7 and the counter electrode 8 may be the same as those of the electrode 2 in the first and second embodiments. The material of the reference electrode 9 is silver / silver chloride.

With this structure, the working electrode, the counter electrode,
Since the reference electrode is formed on one insulating substrate, accurate electrochemical measurement by the three-electrode method becomes possible, and it becomes possible to realize a particularly minute current detection type hydrogen peroxide electrode.
Further, similarly to the second embodiment, it is possible to form the ion exchange resin layer 5 made of perfluorocarbon sulfonic acid resin between the bonding layer 4 and the restricted permeation layer 3.

(Fifth Embodiment) This embodiment shows an example of a method for manufacturing a hydrogen peroxide electrode according to the present invention.

First, a working electrode and a counter electrode made of platinum and a reference electrode made of silver / silver chloride are formed on a substrate made of quartz.

Next, the surface of each electrode and the surface of the substrate are washed. As a cleaning method, a method of cleaning with an organic solvent, an acid or the like, or a method of cleaning with an ultrasonic cleaner can be used, and these methods can be used in combination. As the organic solvent and the acid, those which do not damage the electrode material are used. A polar solvent is preferably used as the organic solvent, and a ketone solvent such as acetone or an alcohol solvent such as isopropyl alcohol can be used. Further, dilute sulfuric acid or the like is used as the acid. In addition, electrolytic cathode water may be used. Electrolytic cathode water refers to a liquid generated on the cathode side when pure water or the like is electrolyzed. Since electrolyzed cathode water has a high reducing property while being neutral to weakly alkaline, it is possible to make the potentials of the substrate surface and the surface of the adhered particles both negative while suppressing damage to the substrate and electrodes. Can be suppressed. Of the above, for example, a method of sequentially washing with acetone and dilute sulfuric acid is preferably used.

Then, bonding layers are formed on the surfaces of the working electrode, the counter electrode and the reference electrode. As described above, a silane coupling agent such as γ-aminopropyltriethoxysilane is preferably used as the material forming the bonding layer.

As a method of applying the coupling agent liquid, etc.,
Spin coating method, spraying method, dipping method, heated air flow method and the like are used. The spin coating method is a method in which a liquid in which constituent materials of the bonding layer such as a coupling agent are dissolved or dispersed is applied by a spin coater. According to this method, it is possible to form a thin coupling layer with good film thickness controllability. The spray method is a method of spraying a coupling agent solution or the like onto a substrate, and the dipping method is a method of immersing the substrate in the coupling agent solution or the like. According to these methods, the bonding layer can be formed by a simple process without requiring a special device. The heated air flow method is a method in which a substrate is placed in a heating atmosphere and vapor of a coupling agent liquid or the like is caused to flow therein. Also by this method, the bonding layer having a small film thickness can be formed with good film thickness controllability.

After applying the coupling agent liquid or the like, it is dried. The drying temperature is not particularly limited, but usually room temperature (25
C.) to 170.degree. C. Although the drying time depends on the temperature, it is usually 0.5 to 24 hours. The drying may be performed in air, but may be performed in an inert gas such as nitrogen. For example, a nitrogen blowing method in which nitrogen is blown onto the substrate to dry it can be used.

After forming the binding layer, a fluoroalcohol ester solution of polycarboxylic acid or the like is applied to form a limited permeation layer. As a method for applying the solution, a spin coating method,
A dip method, a spray method, a brush coating method or the like is used, and among these, a spin coating method, which is excellent in film thickness controllability, is preferably used. When using the spin coating method, 0.01 to 3
It is possible to form the limited permeation layer that is a thin film having a thickness of about μm with good controllability. Alternatively, a method may be used in which the substrate is applied by a dipping method of immersing the substrate in the above-mentioned volume, and then dried while blowing nitrogen gas. According to this method
The restricted permeation layer can be formed by a simple method.

As described above, a hydrogen peroxide electrode in which various layers having specific functions are formed on the electrode is manufactured. In the present embodiment, the working electrode, the counter electrode, and the reference electrode are described as examples in which the coupling layer and the limited permeation layer are provided, but the configuration of the present invention is not limited to this. It is also possible to provide a binding layer and a limited permeation layer on the counter electrode, and sequentially laminate a binding layer and a protective layer for protecting the reference electrode on the reference electrode. In addition, although the hydrogen peroxide sensor including the working electrode, the counter electrode, and the reference electrode has been described in the present embodiment, the working electrode and the reference electrode made of platinum may be provided on the quartz substrate.

(Sixth Embodiment) The present embodiment shows an example of the measuring instrument of the present invention equipped with a hydrogen peroxide sensor, an electrochemical measuring circuit section, a data processing section and a data notifying section. Hereinafter, description will be given with reference to FIG.

This measuring device, as shown in FIG.
The hydrogen peroxide sensor 10, the electrochemical measurement circuit unit 11, the data processing unit 12, and the data notification unit 13 are connected by wiring 14.

The hydrogen peroxide sensor 10 is, for example, the first
The one including the hydrogen peroxide electrode described in the fourth to fourth embodiments can be used. It is preferable that the hydrogen peroxide sensor 10 is a detachable type that can be easily replaced. This is because it is possible to reduce the running cost by replacing only the hydrogen peroxide sensor 10 when the breakage occurs.

As the electrochemical measurement circuit section 11, a potentiostat is used in this embodiment, but the hydrogen peroxide sensor 1
There is no particular limitation as long as it is a circuit that can apply a constant potential to 0 and measure a current value.

A personal computer (hereinafter referred to as a personal computer) is used as the data processing unit 12, but it is not particularly limited as long as it has an arithmetic unit such as a microprocessor capable of processing the signal from the electrochemical measurement circuit unit 11. . The signal processed by the data processing unit 12 is converted into a measurement value and displayed by the data notification unit 13 as the measurement value.

Although the data notifying section 13 uses a display for a personal computer in this embodiment, the data processing section 1
There is no particular limitation as long as it has a function of notifying the data processed by 2. The data processed by the data processing unit 52 is a measurement value calculated by the data processing unit 52.

The wire 54 may be an electric wire that can connect these.

In this embodiment, as shown in FIG. 7A, the hydrogen peroxide sensor 10, the electrochemical measurement circuit section 11,
The data processing unit 12 and the data notification unit 13 are connected to the wiring 14.
However, as shown in FIG. 7B, the data notifying section 1 is provided without the electrochemical measurement circuit section 11.
It is also possible to adopt a configuration in which 3 is directly connected. In this case, the analog signal obtained from the hydrogen peroxide sensor 10 is sent to the data notifying unit 13 as it is, and the measured value is displayed by a display method using a scale and a needle. In this case, it is convenient to attach a table or the like for converting the displayed value into the hydrogen peroxide concentration.

[0105]

The present invention will be described in more detail with reference to the following examples.

Example 1 First, on a 10 mm × 6 mm quartz substrate, a working electrode (area 7 mm ² ) made of platinum and a counter electrode (area 4 mm ² ) and a reference electrode made of silver / silver chloride (area 1) were prepared.
mm ² ) was formed. Next, 1v / v% of γ− on the entire surface
An aminopropyltriethoxysilane solution was spin coated to form a tie layer.

Then, the following two types of hydrogen peroxide electrodes were prepared by changing the configuration of the outermost layer (limited permeation layer). (1) A fluoroalcohol ester of methacrylic acid resin adjusted to 0.3% by mass with perfluorohexane was spin-coated on the entire surface of the bonding layer, and then dried to form a restricted permeation layer. One hydrogen peroxide electrode was produced. The spin coating conditions were 3000 rpm and 30 seconds. As the fluoroalcohol ester of the methacrylic acid resin, Fluorard 722 manufactured by Sumitomo 3M Ltd. was used. Fluorard 722 is polymethacrylic acid 1H, 1H
-Perfluorooctyl, and the average molecular weight (Mn) measured by GPC is about 7,000. As perfluorohexane as a diluting solution, Fluorard 726 manufactured by Sumitomo 3M Ltd. was used. In addition, similarly, the film thickness was measured for the sample in which the fluoroalcohol ester of methacrylic acid resin was directly spin-coated on the quartz substrate.
After the film formation, a part of the film was peeled off with an ultrasonic cutter to generate unevenness, and then the unevenness was measured with an atomic force microscope (SPI3800 manufactured by Seiko Instruments Inc.) to measure the film thickness. The thickness of the fluoroalcohol ester film of the methacrylic acid resin was about 50 nm. (2) A fluoroalcohol ester of an acrylic acid resin adjusted to 0.3% by mass with xylene hexafluoride was applied by spin coating and then dried to form a restricted permeation layer. The hydrogen peroxide electrode was produced as described above. The spin coating conditions were 3000 rpm and 30 seconds. The coating liquid is polyacrylic acid 1H, 1H, 2H,
2H-perfluorodecyl xylene hexafluoride solution (acrylic acid resin content 17%, xylene hexafluoride content 83%, viscosity 20 cps (25
C))) was further adjusted in concentration by adding xylene hexafluoride as described above. In addition, similarly, film thickness measurement was performed on a sample in which fluoroalcohol ester of acrylic acid resin was directly spin-coated on a quartz substrate. After the film formation, a part of the film was peeled off with an ultrasonic cutter to generate unevenness, and then the unevenness was measured with an atomic force microscope (SPI3800 manufactured by Seiko Instruments Inc.) to measure the film thickness. The thickness of the fluoroalcohol ester film of acrylic acid resin is about 100 nm
Met. (3) Spectrophotometer (U-2010 manufactured by Hitachi, Ltd.) and 2 ml
Of quartz glass was prepared and ready for UV absorption measurement at 300 nm. Prepare a slurry containing no hydrogen peroxide, and set the final concentration of hydrogen peroxide to 0.1, 0.5, 1.0,
It was added so as to be 1.5, 2.0 and 2.5 mass%.
Then, the calibration curves of the above-mentioned three kinds of measuring methods were prepared and the measured values were evaluated. The applied potential is the working electrode with respect to the reference electrode.
It was set to 700 mV. As a result of measuring the hydrogen peroxide concentration using the hydrogen peroxide electrode, the correlation coefficient between the actual final concentration of hydrogen peroxide and the measured value of the hydrogen peroxide electrode is obtained by spinning the polyfluoro alcohol ester of methacrylic acid resin. The coated hydrogen peroxide electrode showed 0.991 (Fig. 8 (a)), and the hydrogen peroxide electrode spin-coated with polyfluoroalcohol ester of acrylic acid resin showed 0.987 (Fig. 8 (b)). )). However, the correlation coefficient with the value measured by the absorptiometer was 0.970 (FIG. 8 (c)), and the measurement accuracy was significantly lower than that when the hydrogen peroxide electrode was used. It is considered that the reason why the high correlation coefficient could not be obtained is that the metal and the organic acid in the slurry have the same absorption as hydrogen peroxide. Furthermore, when the response time until the measured value was obtained was also evaluated, the measured value was obtained in 10 seconds for the hydrogen peroxide sensor, whereas the time required for the absorptiometric device to develop color was about 3 minutes. Needed The hydrogen peroxide sensor was able to measure almost in real time. Therefore, the hydrogen peroxide electrode according to the present invention was able to measure hydrogen peroxide in the slurry with high accuracy.

Example 2 First, on a 10 mm × 6 mm quartz substrate, a working electrode (area 7 mm ² ) made of platinum and a counter electrode (area 4 mm ² ) and a reference electrode (area 1) made of silver / silver chloride were prepared.
mm ² ) was formed. Next, 1v / v% of γ− on the entire surface
An aminopropyltriethoxysilane solution was spin coated to form a tie layer.

Using xylene hexafluoride,
A fluoroalcohol ester of acrylic acid resin adjusted to 3% by mass was applied by spin coating and then dried to form a restricted permeation layer. The hydrogen peroxide electrode was produced as described above. Spin coating conditions are 3000 rpm, 3
It was set to 0 seconds. The coating solution is polyacrylic acid 1H, 1H,
Xylene hexafluoride solution of 2H, 2H-perfluorodecyl (acrylic acid resin content 17%, xylene hexafluoride content 83%, viscosity 20 cps (2
5 ° C.)), the concentration of which was further adjusted by adding xylene hexafluoride as described above.

The sensor equipped with the hydrogen peroxide electrode produced as described above was immersed in a slurry containing 1.8% by mass of hydrogen peroxide, and measured once a day for 20 days. The applied potential was 700 mV at the working electrode with respect to the reference electrode. Also,
The surface of the limited permeation layer was observed with a scanning electron microscope (JSM-5410 LV manufactured by JEOL Ltd.) to confirm the state of crack generation. As a result, a stable sensor output was given for at least 20 days, and no cracks were observed on the surface of the restricted permeation layer. FIG. 9 shows the fluctuation of the sensor output for 20 days.

Example 3 First, on a 10 mm × 6 mm quartz substrate, a working electrode (area 7 mm ² ) made of platinum and a counter electrode (area 4 mm ² ) and a reference electrode (area 1) made of silver / silver chloride were prepared.
mm ² ) was formed. Subsequently, 1v / v% γ-aminopropyltriethoxysilane solution was spin-coated on the entire surface to form a bonding layer, and then 5v / v% perfluorocarbon sulfonic acid resin solution was spin-coated to form a perfluorocarbon sulfonic acid resin. An ion exchange resin layer containing (Nafion) as a main component was formed.

Then, a methacrylic acid resin fluoroalcohol ester solution having a concentration of 0.3% by mass was formed thereon by a spin coating method. The conditions for spin coating are 300
It was set to 0 rpm for 30 seconds. As the fluoroalcohol ester of the methacrylic acid resin, Fluorard 722 manufactured by Sumitomo 3M Ltd. was used. The undiluted solution of Florard 722 is 2 when converted to fluoroalcohol ester of methacrylic acid resin.
It is% by mass. Perfluorohexane, which is a diluent,
Fluorard 726 manufactured by Sumitomo 3M Ltd. was used. The film-forming conditions for the fluoroalcohol ester of the methacrylic acid resin are the concentrations appropriately diluted with Florard 726.

A sensor equipped with the hydrogen peroxide electrode manufactured as described above was used, containing 1.8 mass% hydrogen peroxide,
Dipped in the slurry adjusted to 3, 5, and 7
The measurement was performed once for 20 days. The applied potential was 700 mV at the working electrode with respect to the reference electrode. As a result, a stable sensor output was shown regardless of pH (Fig. 13).

Example 4 First, on a 10 mm × 6 mm quartz substrate, a working electrode (area 7 mm ² ) made of platinum and a counter electrode (area 4 mm ² ) and a reference electrode made of silver / silver chloride (area 1) were prepared.
mm ² ) was formed. Subsequently, 1 v / v% γ-aminopropyltriethoxysilane solution was spin-coated to form a bonding layer, and then 5 w / v% perfluorocarbon sulfonic acid resin solution was spin-coated to form a perfluorocarbon sulfonic acid resin (Nafion 2) was formed as a main component.

(1) The entire surface of the bonding layer was spin-coated with a fluoroalcohol ester of a methacrylic acid resin adjusted to 0.3% by mass with perfluorohexane to prepare a first hydrogen peroxide electrode. did. The spin coating conditions were 3000 rpm and 30 seconds. As the fluoroalcohol ester of the methacrylic acid resin, Fluorard 722 manufactured by Sumitomo 3M Ltd. was used. Florard 722
Is 1H, 1H-perfluorooctyl polymethacrylate and has an average molecular weight (Mn) of about 7 measured by GPC.
It is about 000. As perfluorohexane as a diluting solution, Fluorard 726 manufactured by Sumitomo 3M Ltd. was used.

(2) Acrylic acid 1 is formed on the entire surface of the bonding layer.
A xylene hexafluoride solution containing 1.7% by mass of a copolymer of H, 1H, 2H, 2H-perfluorodecyl and cyclohexyl methacrylate was prepared, and this solution was spin-coated to form a second hydrogen peroxide electrode. It was made. The copolymerization ratio of 1H, 1H, 2H, 2H-perfluorodecyl acrylate and cyclohexyl methacrylate is about 8: 2, and the number a of 1H, 1H, 2H, 2H-perfluorodecyl acrylate and the methacrylic acid The ratio a / b of the number b of cyclohexyl groups was about 8/2.

The first or the second produced as described above
Two types of hydrogen peroxide sensors equipped with hydrogen peroxide electrodes of 1.8% by mass hydrogen peroxide at a temperature of 25, 60
The sample was immersed in a slurry adjusted to 0 ° C. and measured once a day for 20 days. The measurement results are shown in (a) and (b) of FIG. 14, respectively. The applied potential was 700 mV at the working electrode with respect to the reference electrode. As a result, the hydrogen peroxide sensor shows stable sensor output regardless of temperature, and in particular, a hydrogen peroxide sensor having a limited permeation layer composed of a copolymer of 1H, 1H, 2H, 2H-perfluorodecyl acrylate and cyclohexyl methacrylate, A particularly stable sensor output was shown at high temperature (Fig. 14).

Example 5 (1) First, a working electrode (area: 7 mm ² ) made of platinum on a quartz substrate of 5 mm × 6 mm, a counter electrode (area: 4 mm ² ) also made of platinum on a quartz substrate of the same area, and Reference electrode made of silver / silver chloride on a quartz substrate of the same area (area 1 mm ² ).
Were formed respectively. (2) Continued, 10 mm x 6
Working electrode made of platinum (area 7 mm
² ), a counter electrode (area: 4 mm ² ), and a reference electrode (area: 1 mm ² ) made of silver / silver chloride on a 5 × 5 mm ² quartz substrate. Subsequently, a 1 v / v% γ-aminopropyltriethoxysilane solution was spin-coated to form a binding layer on the working electrode of (1) and the working electrode of (2) and a counter electrode. A fluorocarbon sulfonic acid resin solution was spin-coated to form an ion exchange resin layer containing a perfluorocarbon sulfonic acid resin (Nafion) as a main component.

(1) Subsequently, the entire surface of the bonding layer, that is, the entire surface of the working electrode, was permeated with perfluorohexane to give 0.1.
A fluoroalcohol ester of methacrylic acid resin adjusted to 3% by mass was spin-coated to prepare a first hydrogen peroxide electrode. Spin coating conditions are 3000 rpm,
It was set to 30 seconds. As the fluoroalcohol ester of the methacrylic acid resin, Fluorard 722 manufactured by Sumitomo 3M Ltd. was used. Fluorard 722 is polymethacrylic acid 1
It is H, 1H-perfluorooctyl, and the average molecular weight (Mn) measured by GPC is about 7,000. As perfluorohexane as a diluting solution, Fluorard 726 manufactured by Sumitomo 3M Ltd. was used.

(2) Subsequently, the entire surface of the bonding layer, that is, the entire surface of the working electrode and the counter electrode was spin-coated with the fluoroalcohol ester of methacrylic acid resin adjusted to 0.3% by mass as in (1). Then, the second hydrogen peroxide electrode was prepared. Two types of hydrogen peroxide sensors each having the first or second hydrogen peroxide electrode manufactured as described above are
Immersing in a slurry containing 1.8 mass% hydrogen peroxide,
The measurement was repeated 10 times continuously to determine the repeatability. The reproducibility was evaluated by determining the coefficient of variation (CV value) of the measured values during repeated measurements. The coefficient of variation refers to a value represented by standard deviation / average value × 100. The applied potential is 70 at the working electrode with respect to the reference electrode.
It was set to 0 mV. As a result, the C.I.
V. The value is 2.8%, and the C.I. V.
The value was 2.4%, and all showed stable sensor output.

(Embodiment 6) This embodiment shows an example of a measuring instrument having the configuration of FIG. 7 (a).

First, the procedure for producing the hydrogen peroxide sensor section of the measuring instrument according to this example will be described. First 10 mm
Working electrode made of platinum (area 7 m on a 6 mm quartz substrate)
m ²⁾ and the counter electrode (area 4 mm ^2), to form a reference electrode of silver / silver chloride (area 1 mm ^2). Next, 1v / v on the whole surface
% Γ-aminopropyltriethoxysilane solution was spin coated to form a tie layer. And 1.7 on it
A limited permeation layer was formed by spin-coating a polyfluoroalcohol ester solution of acrylic acid resin in a mass%. As the polyfluoroalcohol ester of acrylic acid resin, polyacrylic acid 1H, 1H, 2H, 2H-perfluorodecyl was used. Xylene hexafluoride was used as the diluent. Spin coating conditions are 3000 rpm, 3
It was set to 0 seconds.

Using the hydrogen peroxide sensor having the electrode portion formed as described above, a measuring instrument having the structure shown in FIG. 7A was manufactured. The electrode part and the flexible substrate were connected by wire bonding, and the flexible substrate and the electrochemical measurement circuit part were connected using a pin-jack type electric wire.

The electrochemical measuring circuit is a potentiostat HOKUTODENKO POTENTIOSTAT / GALVANOSTAT manufactured by Hokuto Denko.
HA150G was used. As the data processing device, a personal computer PC-9821RaII23 manufactured by NEC Corporation was used. As the data notification unit 53, a display PC-KP531 manufactured by NEC Corporation was used. The electrochemical measurement circuit, the data processing device, and the data notification unit 53 were connected by a pin-jack type electric wire. The hydrogen peroxide sensor equipped with the hydrogen peroxide electrode manufactured as described above was used to monitor hydrogen peroxide in the cleaning liquid containing the actual semiconductor slurry. As the monitoring conditions, the sensor was immersed in a cleaning liquid having a bypass passage, and the hydrogen peroxide concentration converted from the sensor output value was recorded in the memory or the hard disk of the personal computer once every hour. The monitoring took place for 7 days. The applied potential was 700 mV at the working electrode with respect to the reference electrode. As a result, you can monitor the hydrogen peroxide concentration for 7 days,
It was possible to grasp the fluctuations in the hydrogen peroxide concentration for one day and for seven days. It was also possible to analyze the obtained data at a later date.

Further, since the hydrogen peroxide sensor, the electrochemical measurement circuit, and the data processing device are all connected by a pin-jack type electric wire, they can be easily attached and detached between them, and they can be replaced if necessary. It was also shown to be possible.

(Embodiment 7) This embodiment is an example in which the sensor of the present invention is used to control the composition of the CMP polishing liquid. Hereinafter, a manufacturing process of a copper wiring structure using the CMP process performed in this embodiment will be described with reference to the drawings. First, FIG.
As shown in (a), a silicon oxide film 21 is formed on a silicon substrate (not shown), and a silicon nitride film 22 (having a film thickness of about 100 nm) and a silicon oxide film 23 are further formed thereon.
Then, a plurality of wiring trenches 20 reaching the silicon nitride film 22 are formed by dry etching.

Next, as shown in FIG. 16B, the T
A barrier metal film 24 made of aN was formed by a sputtering method. The thickness of the flat portion was about 20 nm. Subsequently, the copper film 25 was formed by the plating method. The film thickness of the copper film 25 was set to about 900 nm in the flat portion having no wiring groove. Subsequently, after performing an annealing treatment, CMP was performed. CM
P was performed using the polishing apparatus shown in FIG. In the figure, the wafer 40 refers to a wafer having a film formed on the surface of the substrate as described above. Wafer 40 formed as described above
Are installed on the lower surface of the wafer carrier 41. While bringing the surface of the wafer 40 into contact with the polishing pad 42, both the wafer carrier 41 and the polishing pad 42 are rotated at a constant speed. The first polishing liquid 44 is supplied between the wafer 40 and the polishing pad 42 from the supply port 43a by the pump 45a.

The first polishing liquid 44 is a solution containing hydrogen peroxide solution and iron nitrate to which alumina particles are added. The hydrogen peroxide concentration of the first polishing liquid 44 is determined by the hydrogen peroxide sensor 4
9a, hydrogen peroxide is replenished based on the measured value obtained. As the hydrogen peroxide sensor 49a, the same sensor as the sensor manufactured and evaluated in Example 2 was used. The hydrogen peroxide sensor 49a is connected to the processing unit 47a that processes the measurement data. The processing unit 47a is a liquid delivery pump 48.
a is controlled, whereby the replenishment amount of the hydrogen peroxide solution 46a to the first polishing liquid 44 is controlled. The hydrogen peroxide solution was replenished when the concentration exceeded a preset range.

When the polishing was continued for a certain period of time using the above polishing apparatus, the rotational torque of CMP increased. At this time, the cross-sectional structure of the substrate is in the state shown in FIG.
That is, the copper plating film 25 on the flat portion of the insulating film is removed and the barrier metal film 24 is exposed.
TaN forming the barrier metal film 24 is the copper plating film 2
It is harder than the copper that constitutes 5 and is less likely to be polished by CMP. Therefore, when TaN is exposed as shown in FIG. 16C, the rotation torque increases.

When the rotational torque increased, the second polishing liquid 50 was supplied between the wafer 40 and the polishing pad 42 by the pump 45b from the supply port 43b of the polishing apparatus shown in FIG. The second polishing liquid 50 is a solution containing hydrogen peroxide water, and has a hydrogen peroxide concentration different from that of the first polishing liquid. The first polishing liquid is a slurry having a composition suitable for polishing a metal film, and the second polishing liquid is a slurry having a composition suitable for polishing a barrier metal film and an insulating film. By thus using the polishing liquids having different compositions together, a wiring structure with less dishing and erosion can be obtained.

The hydrogen peroxide concentration of the second polishing liquid 50 is measured by the hydrogen peroxide sensor 49b, and the hydrogen peroxide is replenished based on the obtained measured value. As the hydrogen peroxide sensor 49b, the same sensor as the sensor manufactured and evaluated in Example 2 was used. The hydrogen peroxide sensor 49b is connected to the processing unit 47b that processes the measurement data. Processing unit 47b
Controls the liquid feed pump 48b, which controls the replenishment amount of the hydrogen peroxide solution 46b to the second polishing liquid 50. The hydrogen peroxide solution 46b was replenished by a method of replenishing when the concentration range exceeded a preset range.

Then, polishing was continued for a predetermined time to form a copper wiring 26 as shown in FIG. 16 (d).
The end point of CMP was determined using a method of detecting a change in the rotational torque of CMP.

The above process is repeated a plurality of times,
The CMP process was performed on a plurality of wafers. During the CMP process, the hydrogen peroxide concentrations of the first polishing liquid 44 and the second polishing liquid 50 change with time. In this embodiment, the hydrogen peroxide sensors 49a and 49b are used to measure the hydrogen peroxide concentration. Since hydrogen peroxide was replenished appropriately, it was possible to maintain the liquid composition of the polishing liquid constant and maintain the polishing performance excellent.
Therefore, the wiring structure with less dishing and erosion could be stably manufactured.

(Embodiment 8) This embodiment is an example in which the sensor of the present invention is used for controlling the composition of the resist stripping solution. FIG. 18 is a schematic diagram of the resist stripping apparatus used in this example. The processing bath 58 is filled with the stripping solution 52,
A silicon wafer 51 to be processed is arranged in a dipped state. The stripping solution 52 is composed of a mixed solution (APM) containing ammonia and hydrogen peroxide, and is kept at 60 ° C. by a heater (not shown). A hydrogen peroxide sensor 53 is immersed in the stripping solution 52. This hydrogen peroxide sensor 53 was manufactured and evaluated in Example 4, and acrylic acid 1
The same hydrogen peroxide sensor (sensor corresponding to the evaluation result of FIG. 14B) having a restricted permeation layer composed of a copolymer of H, 1H, 2H, 2H-perfluorodecyl and cyclohexyl methacrylate was used. .

The hydrogen peroxide sensor 53 is connected to the processing unit 54 which processes the measurement data. The processing unit 54 controls the liquid feed pump 55, and thereby controls the replenishment amount of the hydrogen peroxide solution 56 from the storage tank 57 in which the hydrogen peroxide solution is stored to the processing tank 58.

Using the stripping apparatus having the above-described structure, the resist stripping of a plurality of wafers was continuously performed. For the replenishment of hydrogen peroxide, the relationship between the hydrogen peroxide concentration and the resist stripping ability was previously obtained, and the hydrogen peroxide solution 56 was replenished when the resist stripping ability became a certain reference value or less.

In this embodiment, since the sensor provided with the hydrogen peroxide electrode having the specific structure was used, the hydrogen peroxide concentration in the stripping solution could be accurately quantified. Therefore, it is possible to appropriately replenish an appropriate amount of hydrogen peroxide based on the measured value of hydrogen peroxide concentration, and strictly control and manage the liquid composition,
The resist could be peeled off stably.

(Example 9) A plurality of sheets were prepared in the same manner as in Example 8 except that the stripping solution was changed to a substrate cleaning solution (a mixed solution of ammonia and hydrogen peroxide solution) and the resist stripping apparatus was changed to a cleaning apparatus. Part of the RCA cleaning process was performed on the bare wafer. The schematic configuration of the cleaning device has the same configuration as the resist stripping device of FIG. The treatment temperature was 60 ° C. as in Example 8. Regarding the replenishment of hydrogen peroxide, the relationship between the concentration of hydrogen peroxide and the cleaning ability was previously obtained, and when the cleaning ability was below a certain reference value, the hydrogen peroxide solution was replenished.

In this example, since the sensor provided with the hydrogen peroxide electrode having the specific structure was used, the hydrogen peroxide concentration in the cleaning liquid could be accurately quantified. Therefore, it is possible to appropriately replenish an appropriate amount of hydrogen peroxide based on the measured value of hydrogen peroxide concentration, and strictly control and manage the liquid composition,
Stable washing could be performed.

As described above, the hydrogen peroxide sensor of the present invention is particularly effective when applied to the manufacture of semiconductor devices. The present invention provides a hydrogen peroxide electrode, a hydrogen peroxide sensor using the same, and the like. Further, the following methods and devices are also provided. (i) A method for measuring hydrogen peroxide concentration, which comprises measuring the hydrogen peroxide concentration in a CMP polishing liquid using the hydrogen peroxide sensor of the present invention. (ii) A polishing apparatus for chemically and mechanically polishing a semiconductor wafer using a polishing liquid containing hydrogen peroxide, comprising the hydrogen peroxide sensor of the present invention. (iii) In the polishing apparatus of (ii), the replenishment amount of hydrogen peroxide to the polishing liquid is controlled based on the hydrogen peroxide concentration in the polishing liquid measured by the hydrogen peroxide sensor of the present invention. Characteristic polishing device. (iv) A method for measuring hydrogen peroxide concentration, which comprises measuring the hydrogen peroxide concentration in a resist stripping solution using the hydrogen peroxide sensor of the present invention. (v) A resist stripping apparatus for removing a resist film provided on a semiconductor wafer by using a resist stripping solution containing hydrogen peroxide, wherein the resist stripping apparatus comprises the hydrogen peroxide sensor of the present invention. . (vi) In the resist stripping apparatus of (v), the replenishment amount of hydrogen peroxide to the resist stripping solution is controlled based on the hydrogen peroxide concentration in the resist stripping solution measured by the hydrogen peroxide sensor of the present invention. A resist stripping device characterized by the above. (vii) A method for measuring hydrogen peroxide concentration, which comprises measuring the hydrogen peroxide concentration in a wafer cleaning liquid using the hydrogen peroxide sensor of the present invention. (viii) A cleaning device for cleaning a semiconductor wafer using a cleaning liquid containing hydrogen peroxide, comprising the hydrogen peroxide sensor of the present invention. (ix) In the cleaning device of (viii), the replenishment amount of hydrogen peroxide to the cleaning liquid is controlled based on the hydrogen peroxide concentration in the cleaning liquid measured by the hydrogen peroxide sensor of the present invention. Cleaning equipment.

[0141]

As described above, the hydrogen peroxide electrode of the present invention and the hydrogen peroxide sensor using the same have the following effects because they have a restricted permeation layer composed of a polymer having a specific structure. Play.

The first effect is that sufficiently high precision measurement values can be obtained. In addition to suppressing the attachment of pollutants,
This is because the influence of substances that interfere with the determination of hydrogen peroxide can be effectively eliminated.

The second effect is that adhesion of contaminants is suppressed and stable output characteristics can be obtained even after long-term use. This is because a pendant group containing a fluoroalkylene block such as a fluoroalcohol ester group is hardly soluble in most non-fluorine-based solvents and detergents such as surfactants. Therefore, stable repeated measurement results can be obtained even in a component system containing various chemical substances such as precipitates such as CMP slurries and organic acids.

The third effect is that good adhesion to the electrode and other organic polymer layers can be obtained, the response speed can be increased, the time required for cleaning can be shortened, and the durability of the layer structure can be improved. Is obtained, and a hydrogen peroxide electrode that is less likely to be damaged even when used for a long period of time is obtained. The reason why good adhesion is obtained is that the polymer constituting the restricted permeation layer has a main chain made of a vinyl polymer containing no fluorine. The pendant group has a structure in which it is bonded to the main chain via an ester group, so that the adhesion can be further improved.

The fourth effect is that good limiting permeability can be obtained and the measurement concentration range can be greatly expanded. The reason why good restricted permeability is obtained is that the polymer constituting the restricted permeability layer is a fluorine-free vinyl polymer,
By having a unique structure in which a pendant group containing at least a fluoroalkylene block is bonded.

The fifth effect is that since the limited permeability is good, the layer thickness of the limited permeation layer can be made thin, and the response speed can be increased and the time required for cleaning can be shortened. .

The sixth effect is that the hydrogen peroxide electrode and the hydrogen peroxide sensor of the present invention are applied to the determination of the hydrogen peroxide concentration of various chemicals used in the manufacture of semiconductor devices, whereby the cost of the chemicals is greatly reduced. In addition, it is possible to reduce variations in processes such as cleaning, resist stripping, and polishing for each batch.

The seventh effect is that the concentration of hydrogen peroxide used in the disinfection and sterilization steps of the food manufacturing process can be continuously monitored. The reason is that proteins and the like contained in food hardly adhere to the electrodes, and therefore high measurement accuracy can be maintained.

Further, according to the present invention, a hydrogen peroxide electrode and a hydrogen peroxide sensor having excellent mass productivity can be obtained. Since the hydrogen peroxide electrode of the present invention can be formed by applying its various layer structures by spin coating or the like,
This is because most of the existing planar manufacturing process can be used, and mass production can be performed at low cost.

Further, since the measuring instrument of the present invention has the hydrogen peroxide sensor having the working electrode of the specific structure, it is excellent in long-term stability and can be used under a wide range of measuring conditions. . Moreover, the operation method is simple, and even a person unfamiliar with the device can easily handle it.

Further, in the method for producing a hydrogen peroxide electrode of the present invention, since the limited permeation layer is formed by applying and drying a liquid containing a polymer component having a specific structure, stability during repeated measurement, and adjacent layers It is possible to form a limited permeation layer having excellent adhesion, durability, limited permeation property, etc. with good film thickness controllability.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a hydrogen peroxide electrode of the present invention.

FIG. 2 is a sectional view of a hydrogen peroxide electrode of the present invention.

FIG. 3 is a cross-sectional view of a hydrogen peroxide electrode of the present invention.

FIG. 4 is a sectional view of a hydrogen peroxide electrode of the present invention.

FIG. 5 is a diagram showing an example of the configuration of a hydrogen peroxide sensor of the present invention.

FIG. 6 is a diagram showing an example of the configuration of a hydrogen peroxide sensor of the present invention.

FIG. 7 is a diagram showing an example of the configuration of a measuring instrument of the present invention.

FIG. 8 is a diagram showing the measurement accuracy of the hydrogen peroxide electrode of the present invention.

FIG. 9 is a diagram showing the stability of repeated measurements of the hydrogen peroxide electrode of the present invention.

FIG. 10 is a diagram showing a conventional device for measuring the concentration of hydrogen peroxide.

FIG. 11 is a diagram showing characteristics of a conventional device for measuring hydrogen peroxide concentration.

FIG. 12 is a cross-sectional view of a conventional hydrogen peroxide electrode.

FIG. 13 is a diagram showing the stability of the hydrogen peroxide electrode of the present invention.

FIG. 14 is a diagram showing the stability of the hydrogen peroxide electrode of the present invention.

FIG. 15 is a diagram showing data showing the absorbance of hydrogen peroxide by a conventional device.

FIG. 16 is a process sectional view explaining the manufacturing process of the copper wiring structure using the CMP process.

FIG. 17 is a diagram showing a schematic configuration of a CMP polishing apparatus equipped with the hydrogen peroxide sensor of the present invention.

FIG. 18 is a diagram showing a schematic configuration of a resist stripping apparatus equipped with the hydrogen peroxide sensor of the present invention.

[Explanation of symbols]

1 Insulation board 2 electrodes 3 Restricted transmission layer 4 Bonding layer 5 Ion exchange resin layer 7 Working pole 8 opposite poles 9 reference pole 10 Hydrogen peroxide sensor 11 Electrochemical measurement circuit 12 Data processing unit 13 Data notification section 14 wiring 20 wiring groove 21 Silicon oxide film 22 Silicon nitride film 23 Silicon oxide film 24 Barrier metal film 25 copper film 26 copper wiring 31 insulating substrate 32 Hydrogen peroxide electrode 33 γ-aminopropyltriethoxysilane film 34 Acetyl cellulose membrane 35 Perfluorocarbon sulfonic acid resin membrane 36 Organic polymer membrane with immobilized enzyme having catalytic function 37 Polyalkyl siloxane film 40 wafers 41 Wafer carrier 42 polishing pad 43 Supply port 44 First polishing liquid 45a, 45b pump 46a, 46b Hydrogen peroxide water 47a, 47b Processing unit 48a, 48b Liquid transfer pump 49a, 49b Hydrogen peroxide sensor 50 Second polishing liquid 51 Silicon wafer 52 Stripper 53 Hydrogen peroxide sensor 54 Processing Unit 55 Liquid Delivery Pump 56 Hydrogen peroxide water 57 Storage tank 58 treatment tank 61 pumps 62 flow path switching valve 63 pumps 66 loops 72 Flow path switching valve 73 pumps 76a loop 76b loop 81 Cooler 82 Defoamer 84 Check valve 85 Mixer 86 Ultraviolet absorption measurement unit 86a UV light source 86b flow cell 86c UV detector 89 Degassing device

Continuation of the front page (56) References JP 2000-146896 (JP, A) JP 2000-81409 (JP, A) JP 2000-81410 (JP, A) JP 2001-41919 (JP, A) Special Kaihei 3-277960 (JP, A) JP 10-26601 (JP, A) JP 8-136450 (JP, A) JP 3-175341 (JP, A) JP-B 6-43734 ( JP, B2) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01N 27/416 G01N 27/333 JISC file (JOIS)

Claims (41)

(57) [Claims] 1. An electrode provided on an insulating substrate, and a limited permeation layer covering at least a part of the electrode, wherein the limited permeation layer is at least fluororesin with respect to a fluorine-free vinyl polymer. A hydrogen peroxide electrode, which is mainly composed of a polymer having pendant groups containing an alkylene block bonded thereto. 2. The vinyl polymer is a homopolymer or copolymer of one or more monomers selected from the group consisting of unsaturated hydrocarbons, unsaturated carboxylic acids, and unsaturated alcohols. The hydrogen peroxide electrode according to claim 1. 3. The hydrogen peroxide electrode according to claim 1, wherein the vinyl polymer is a polycarboxylic acid. 4. The hydrogen peroxide electrode according to claim 1, wherein the fluoroalkylene block is bonded to the vinyl polymer via an ester group. 5. When the number of fluorine atoms contained in the pendant group is x and the number of hydrogen atoms contained in the pendant group is y, the fluorine content of the pendant group represented by x / (x + y). The hydrogen peroxide electrode according to any one of claims 1 to 4, wherein the rate is 0.3 to 1. 6. The hydrogen peroxide electrode according to claim 1, wherein the pendant group has 3 to 15 carbon atoms. 7. The molecular weight of the polymer is from 1000 to 5
The hydrogen peroxide electrode according to any one of claims 1 to 6, which is 0000. 8. An electrode provided on an insulating substrate, and a limited permeation layer covering at least a part of the electrode. The limited permeation layer is mainly composed of fluoroalcohol ester of polycarboxylic acid (A). A hydrogen peroxide electrode characterized in that 9. An electrode provided on an insulating substrate, and a limited permeation layer covering at least a part of the electrode, the limited permeation layer comprising a fluoroalcohol ester of polycarboxylic acid (A) and A hydrogen peroxide electrode comprising an alkyl alcohol ester of carboxylic acid (B). 10. The hydrogen peroxide electrode according to claim 9, wherein the polycarboxylic acid (B) is polymethacrylic acid, polyacrylic acid, or a copolymer of acrylic acid and methacrylic acid. 11. The alkyl alcohol ester of polycarboxylic acid (B) is an ester compound obtained by esterifying at least a part of a carboxyl group of polycarboxylic acid (B) with an alkyl alcohol having 2 to 10 carbon atoms. The hydrogen peroxide electrode according to claim 9, wherein the hydrogen peroxide electrode is present. 12. The hydrogen peroxide electrode according to claim 11, wherein the alkyl alcohol ester of polycarboxylic acid (B) is cyclohexyl polymethacrylate. 13. The polymer according to claim 8, wherein the polycarboxylic acid (A) is polymethacrylic acid, polyacrylic acid, or a copolymer of acrylic acid and methacrylic acid. Hydrogen oxide electrode. 14. When the number of fluorine atoms in the fluoroalcohol ester group contained in the fluoroalcohol ester of the polycarboxylic acid (A) is x and the number of hydrogen atoms is y, it is represented by x / (x + y). The hydrogen peroxide electrode according to any one of claims 8 to 13, wherein the fluorine content of the fluoroalcohol ester group is 0.3 to 1. 15. The carbon number of fluoroalcohol constituting the fluoroalcohol ester group contained in the fluoroalcohol ester of the polycarboxylic acid (A) is 3 to 1.
15. The hydrogen peroxide electrode according to claim 8, wherein the hydrogen peroxide electrode is 5. 16. The fluoroalcohol constituting the fluoroalcohol ester group contained in the fluoroalcohol ester of the polycarboxylic acid (A) is a primary alcohol, and the fluoroalcohol according to any one of claims 8 to 15. Hydrogen oxide electrode. 17. The fluoroalcohol ester of polycarboxylic acid (A) is polymethacrylic acid 1H, 1H-
It is perfluorooctyl, It is characterized by the above-mentioned.
The hydrogen peroxide electrode according to item 6. 18. The fluoroalcohol ester of polycarboxylic acid (A) is polyacrylic acid 1H, 1H, 2
The hydrogen peroxide electrode according to claim 16, which is H, 2H-perfluorodecyl. 19. The molecular weight of the fluoroalcohol ester of the polycarboxylic acid (A) is 1,000 to 50,000.
The hydrogen peroxide electrode according to any one of claims 8 to 18, which is 20. An electrode provided on an insulating substrate, and a restricted permeation layer covering at least a part of the electrode, wherein the restricted permeation layer is a polycarboxylic acid having an alkyl alcohol ester group and a fluoro alcohol ester group. A hydrogen peroxide electrode, which is mainly composed of an acid ester compound. 21. When the number of fluorine atoms in the fluoroalcohol ester group is x and the number of hydrogen atoms is y, x
The hydrogen peroxide electrode according to claim 20, wherein the fluorine content of the fluoroalcohol ester group represented by / (x + y) is 0.3 to 1. 22. The hydrogen peroxide electrode according to claim 20, wherein the fluoroalcohol constituting the fluoroalcohol ester group has 3 to 15 carbon atoms. 23. The hydrogen peroxide electrode according to claim 20, wherein the fluoroalcohol constituting the fluoroalcohol ester group is a primary alcohol. 24. The hydrogen peroxide electrode according to claim 23, wherein the fluoroalcohol ester group is 1H, 1H-perfluorooctyl polymethacrylate. 25. The hydrogen peroxide electrode according to claim 23, wherein the fluoroalcohol ester group is a polyacrylic acid 1H, 1H, 2H, 2H-perfluorodecyl group. 26. The hydrogen peroxide electrode according to claim 20, wherein the alkyl alcohol ester group has 2 to 10 carbon atoms. 27. The hydrogen peroxide electrode according to claim 26, wherein the alkyl alcohol ester group is polycyclohexyl methacrylate. 28. The limited permeation layer has a thickness of 0.01 μm.
The hydrogen peroxide electrode according to any one of claims 1 to 27, which has a thickness of 3 m or more and 3 m or less. 29. Between the electrode and the limited permeation layer,
The hydrogen peroxide electrode according to any one of claims 1 to 28, which has a bonding layer mainly composed of a silane coupling agent. 30. The hydrogen peroxide electrode according to claim 29, wherein the silane coupling agent is γ-aminopropyltriethoxysilane. 31. The peroxide according to claim 29, wherein an ion exchange resin layer mainly composed of an ion exchange resin having a perfluorocarbon skeleton is provided between the binding layer and the restricted permeation layer. Hydrogen electrode. 32. A hydrogen peroxide sensor using the hydrogen peroxide electrode according to claim 1 as a working electrode. 33. The hydrogen peroxide sensor according to claim 32, which is used for measuring a hydrogen peroxide concentration of a polishing liquid used for chemical mechanical polishing of a semiconductor wafer. 34. The method according to claim 32, which is used for measuring a hydrogen peroxide concentration of a resist stripping solution used for removing a resist film provided on a semiconductor wafer.
Hydrogen peroxide sensor described in. 35. The hydrogen peroxide sensor according to claim 32, which is used for measuring a hydrogen peroxide concentration of a cleaning liquid used for cleaning a semiconductor wafer. 36. A measurement comprising the hydrogen peroxide sensor according to any one of claims 32 to 35, and a data notifying unit for notifying an electric signal obtained from the hydrogen peroxide sensor. vessel. 37. The hydrogen peroxide sensor according to claim 32, an electrochemical measuring circuit section for obtaining an electric signal from the hydrogen peroxide sensor, and a measurement value is calculated based on the electric signal. A measuring instrument comprising a data processing unit and a data notifying unit for notifying the measured value. 38. A step of forming an electrode on an insulating substrate,
A liquid containing a polymer in which a pendant group having at least a fluoroalkylene block is bonded to a fluorine-free vinyl polymer is applied to the electrode directly or through another layer, followed by drying, and then the limited permeation layer. And a step of forming a hydrogen peroxide electrode. 39. The method for producing a hydrogen peroxide electrode according to claim 38, wherein the liquid is applied by a spin coating method. 40. The method for producing a hydrogen peroxide electrode according to claim 38, which comprises applying the liquid by a dipping method and then performing drying while spraying nitrogen gas. 41. The method for producing a hydrogen peroxide electrode according to claim 38, wherein the thickness of the limited permeation film is 0.01 μm or more and 3 μm or less after drying.