JP2018199809A - Detergent - Google Patents

Abstract

To provide a detergent that has low metal corrosiveness, is less likely to foam during cleaning, prevents monomer contamination of a substrate, and has no restrictions in pH at the time of use.SOLUTION: A detergent contains an aniline polymer having an acidic group, and water, and is suitable as a detergent for a flat panel display substrate or semiconductor device substrate, wherein the content of raw material monomer for the aniline polymer is 500 mass ppm or less.SELECTED DRAWING: None

Description

  The present invention relates to a cleaning agent suitable for cleaning flat panel display substrates, semiconductor device substrates, and the like.

  In a flat panel display (FPD) manufacturing process, a metal film and a resist film are sequentially formed on a substrate such as glass, and then the resist film is exposed, developed, and patterned to form a resist pattern. Things have been done. After the resist pattern is formed, a portion on which the resist is not formed is selectively etched, and the metal scrap and resist film generated by the etching are removed to obtain a substrate on which the resist pattern is formed.

A semiconductor device has a flattened surface by forming a metal film or the like on a substrate such as a silicon wafer and then performing a surface flattening process by chemical mechanical polishing (CMP) using an abrasive. Manufactured by stacking new layers on top.
Since the abrasive used in the CMP process and metal polishing residue are likely to remain on the surface of the substrate after the CMP process, it is necessary to clean the substrate.

Conventionally, a cleaning agent containing an anionic surfactant has been used for cleaning an FPD substrate or a semiconductor device substrate.
However, the cleaning agent containing an anionic surfactant sometimes corrodes the metal film formed on the substrate. There is also a problem that bubbles are easily formed during cleaning, and the bubbles remain on the substrate.

Therefore, as a detergent that does not easily foam, for example, Patent Document 1 discloses sulfamic acid, an anionic surfactant having a sulfonic acid group in the molecule and a mass average molecular weight of 1,000 to 2,000,000, a chelating agent, and water. A cleaning agent containing and having a pH of 3 or less is disclosed.
In addition, as a detergent that does not contain a surfactant, for example, Patent Document 2 discloses a detergent that contains aminobenzenesulfonic acid, a water-miscible organic solvent, and water and has a pH of 6 to 11. ing.

JP 2010-163609 A JP 2009-224782 A

  However, the cleaning agent described in Patent Document 1 uses a high molecular weight anionic surfactant and thus is relatively difficult to foam, but does not necessarily satisfy the foaming prevention property and is inferior in corrosion prevention. Moreover, there was a restriction of pH during use.

On the other hand, since the cleaning agent described in Patent Document 2 does not contain an anionic surfactant, it is difficult to foam and has low corrosiveness to metals.
However, aminobenzenesulfonic acid contained in the cleaning agent is difficult to dissolve in water and tends to be suspended even when mixed with water. Therefore, aminobenzenesulfonic acid was easy to adhere on the substrate. If the cleaning agent is made alkaline, aminobenzenesulfonic acid can be easily dissolved in water. However, if divalent metal ions (such as copper ions) are present in water, the metal ions and aminobenzenesulfonic acid are A precipitate is formed by the reaction, and the precipitate is deposited on the substrate.
Thus, the cleaning agent described in Patent Document 2 has a problem of monomer contamination on the substrate. Moreover, there was a restriction of pH during use.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a cleaning agent that has low corrosiveness to metals, is difficult to foam during cleaning, can prevent monomer contamination on a substrate, and has no pH restriction during use. And

The present invention has the following aspects.
[1] A cleaning agent comprising an aniline polymer having an acidic group and water, wherein the content of the raw material monomer of the aniline polymer is 500 mass ppm or less.
[2] The cleaning agent according to [1], wherein the aniline polymer has a unit represented by the following general formula (1).

In formula (1), R ^{1 to} R ⁴ each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 24 carbon atoms, a linear or branched alkoxy group having 1 to 24 carbon atoms, or an acidic group. , A hydroxy group, a nitro group, and a halogen atom, and at least one of R ^{1 to} R ⁴ is an acidic group. Here, the acidic group is a sulfonic acid group or a carboxy group.

[3] The cleaning agent according to [1] or [2], which is for a flat panel display substrate or a semiconductor device substrate.

  According to the cleaning agent of the present invention, the corrosiveness to metal is low, it is difficult to foam during cleaning, monomer contamination to the substrate can be prevented, and there is no restriction of pH during use.

Hereinafter, the present invention will be described in detail.
In the present invention, “cleaning” includes not only removing an object to be cleaned (for example, metal shaving residue, polishing residue, abrasive), but also removing (stripping) a resist film, for example.
In the present invention, “water-soluble” and “solubility” mean that 0.1 g or more is uniformly dissolved in 10 g of water or a mixed solvent of water and a water-soluble organic solvent (liquid temperature: 25 ° C.). To do.

[Washing soap]
The cleaning agent of the present invention contains an aniline polymer having an acidic group and water.

<Aniline polymer>
An aniline-based polymer has an acidic group. The aniline polymer is water-soluble and has excellent solubility in water.
Here, the “acidic group” is a sulfonic acid group (—SO ₃ H) or a carboxy group (—COOH).
The sulfonic acid group includes a substituent having a sulfonic acid group (—R ⁵ SO ₃ H), an alkali metal salt, an ammonium salt, or a substituted ammonium salt of the sulfonic acid group.
On the other hand, the carboxy group includes a substituent having a carboxy group (—R ⁵ COOH), an alkali metal salt, an ammonium salt or a substituted ammonium salt of the carboxy group.
R ⁵ represents a linear or branched alkylene group having 1 to 24 carbon atoms, an arylene group or an aralkylene group.

The aniline polymer is not particularly limited as long as it has an acidic group, and a known aniline polymer can be used.
Specifically, any one of the following (i) to (iii) is placed on a skeleton in a π-conjugated polymer such as polyaniline or polydiaminoanthraquinone having an unsubstituted or substituted group or a nitrogen atom in the π-conjugated polymer. The polymer which has is mentioned.
(I) Acid group (ii) Alkali metal salt, ammonium salt or substituted ammonium salt of acid group (iii) Alkyl group substituted with any of acid group, alkali metal salt of acid group, ammonium salt or substituted ammonium salt or Alkyl group containing an ether bond

Among these, a polymer containing a polyaniline skeleton is preferable from the viewpoint of excellent solubility in water.
In particular, a polymer containing 20 to 100 mol% of a unit represented by the following general formula (2) in all units (100 mol%) constituting the polymer is preferable from the viewpoint of expressing high solubility.

式（２）中、Ｒ^６〜Ｒ^１０は各々独立に、水素原子、炭素数１〜２４の直鎖もしくは分岐のアルキル基、炭素数１〜２４の直鎖もしくは分岐のアルコキシ基、酸性基、ヒドロキシ基、ニトロ基、ハロゲン原子、−Ｎ(Ｒ^１１)_２、−ＮＨＣＯＲ^１１、−ＳＲ^１１、−ＯＣＯＲ^１１、−ＣＯＯＲ^１１、−ＣＯＲ^１１、−ＣＨＯ、および−ＣＮからなる群より選ばれ、Ｒ^１１は炭素数１〜２４の直鎖もしくは分岐のアルキル基、アリール基またはアラルキル基を表す。
ただし、Ｒ^６〜Ｒ^１０のうちの少なくとも１つは酸性基である。

In formula (2), R ^{6 to} R ¹⁰ are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 24 carbon atoms, a linear or branched alkoxy group having 1 to 24 carbon atoms, an acidic group, A hydroxy group, a nitro group, a halogen atom, —N (R ¹¹ ) ₂ , —NHCOR ¹¹ , —SR ¹¹ , —OCOR ¹¹ , —COOR ¹¹ , —COR ¹¹ , —CHO, and —CN; R ¹¹ represents a linear or branched alkyl group, aryl group or aralkyl group having 1 to 24 carbon atoms.
However, at least one of R ^{6 to} R ¹⁰ is an acidic group.

  As the aniline-based polymer, a polymer having a unit represented by the following general formula (1) is preferable from the viewpoint of superior solubility in water among the polymers having the unit represented by the general formula (2).

In formula (1), R ^{1 to} R ⁴ each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 24 carbon atoms, a linear or branched alkoxy group having 1 to 24 carbon atoms, or an acidic group. , A hydroxy group, a nitro group, and a halogen atom, and at least one of R ^{1 to} R ⁴ is an acidic group.
As the acidic group, a sulfonic acid group is preferable.

As the unit represented by the general formula (1), one of R ^{1 to} R ⁴ is a linear or branched alkoxy group having 1 to 4 carbon atoms in terms of easy production, Any one of these is a sulfonic acid group, and the remainder is a hydrogen atom.

From the viewpoint of excellent solubility in water regardless of pH, the aniline polymer contains 10 to 100 mol% of units represented by the general formula (1) among all units (100 mol%) constituting the aniline polymer. It is preferable to contain, it is more preferable to contain 50-100 mol%, and it is especially preferable to contain 100 mol%.
The aniline polymer preferably contains 10 or more units represented by the general formula (1) in one molecule.

  In addition, from the viewpoint of improving solubility, the aniline-based polymer preferably has 70% or more, more preferably 80% or more of the number of aromatic rings to which acidic groups are bonded to the total number of aromatic rings in the polymer. Preferably, it is 90% or more.

  Furthermore, the aniline-based polymer is a structural unit other than the unit represented by the general formula (1) as long as it does not affect the solubility or the like, and is substituted or unsubstituted aniline, thiophene, pyrrole, phenylene, vinylene, diene. One or more units selected from the group consisting of a valent unsaturated group and a divalent saturated group may be included.

  As the aniline-based polymer, a compound having a structure represented by the following general formula (3) is preferable from the viewpoint of exhibiting high solubility.

In formula (3), R ^{12 to} R ²⁷ are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 24 carbon atoms, a linear or branched alkoxy group having 1 to 24 carbon atoms, or an acidic group. , A hydroxy group, a nitro group, and a halogen atom, and at least one of R ^{12 to} R ²⁷ is an acidic group. N represents the degree of polymerization.

  Among the compounds having the structure represented by the general formula (3), poly (2-sulfo-5-methoxy-1,4-iminophenylene), poly (2-methoxyaniline-5) are excellent in solubility. -Sulfonic acid) is particularly preferred.

The mass average molecular weight of the aniline-based polymer is preferably 3000 to 1000000, more preferably 5000 to 80000, and particularly preferably 10,000 to 70000.
Here, the mass average molecular weight of the aniline polymer is a mass average molecular weight (in terms of sodium polystyrene sulfonate) measured by gel permeation chromatography (GPC).

(Method for producing aniline polymer)
The aniline polymer can be produced by a known method. For example, at least one compound (raw material monomer) selected from the group consisting of acidic group-substituted anilines, alkali metal salts, ammonium salts and substituted ammonium salts thereof is polymerized using an oxidizing agent in the presence of a basic reaction aid. It is obtained by doing.

Examples of the acidic group-substituted aniline include sulfonic acid group-substituted anilines having a sulfonic acid group as an acidic group.
Typical examples of the sulfone group-substituted aniline are aminobenzene sulfonic acids, specifically 2-aminobenzene sulfonic acid, 3-aminobenzene sulfonic acid, 4-aminobenzene sulfonic acid, aniline-2,6-disulfone. Acid, aniline-2,5-disulfonic acid, aniline-3,5-disulfonic acid, aniline-2,4-disulfonic acid, aniline-3,4-disulfonic acid and the like are preferably used.

Examples of sulfone group-substituted anilines other than aminobenzenesulfonic acids include methylaminobenzenesulfonic acid, ethylaminobenzenesulfonic acid, n-propylaminobenzenesulfonic acid, iso-propylaminobenzenesulfonic acid, n-butylaminobenzenesulfonic acid, alkyl group-substituted aminobenzenesulfonic acids such as sec-butylaminobenzenesulfonic acid and t-butylaminobenzenesulfonic acid; methoxyaminobenzenesulfonic acid (for example, 2-methoxyaniline-5-sulfonic acid, 2-methoxyaniline-3-sulfone) Acid, 3-methoxyaniline-2-sulfonic acid, 3-methoxyaniline-5-sulfonic acid, etc.), alkoxy group-substituted aminobenzes such as ethoxyaminobenzenesulfonic acid, propoxyaminobenzenesulfonic acid, etc. Hydroxy group-substituted aminobenzenesulfonic acids; Nitro group-substituted aminobenzenesulfonic acids; Halogen-substituted aminobenzenesulfonic acids such as fluoroaminobenzenesulfonic acid, chloroaminobenzenesulfonic acid, bromoaminobenzenesulfonic acid, etc. .
Among these, an alkyl group-substituted aminobenzene sulfonic acid, an alkoxy group-substituted aminobenzene sulfonic acid, a hydroxy group-substituted aminobenzene sulfonic acid, or a halogen-substituted aminobenzene sulfone is obtained in that an aniline polymer having particularly excellent solubility is obtained. Acids are preferred, and alkoxy group-substituted aminobenzenesulfonic acids, alkali metal salts, ammonium salts and substituted ammonium salts thereof are particularly preferred in terms of easy production.
Each of these sulfonic acid group-substituted anilines may be used alone or in a mixture of two or more at any ratio.

Examples of the basic reaction aid used in the production of the aniline polymer include inorganic bases, ammonia, fatty amines, cyclic saturated amines, cyclic unsaturated amines, and the like.
As the basic reaction aid, an inorganic base is preferable, and specific examples include sodium hydroxide, potassium hydroxide, lithium hydroxide and the like.
In addition to inorganic bases, fatty amines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethylmethylamine, ethyldimethylamine, diethylmethylamine; pyridine, α-picoline, β-picoline, γ -Cyclic unsaturated amines such as picoline are preferably used as basic reaction aids.
Each of these basic reaction aids may be used alone or in admixture of two or more at any ratio.

The oxidizing agent used in the production of the aniline polymer is not limited as long as the standard electrode potential is 0.6 V or more. For example, peroxodisulfuric acid, ammonium peroxodisulfate, sodium peroxodisulfate, peroxodisulfuric acid It is preferable to use peroxodisulfuric acid such as potassium; hydrogen peroxide or the like.
Each of these oxidizing agents may be used alone, or two or more kinds thereof may be mixed and used in an arbitrary ratio.

  As a polymerization method, for example, a method of dropping a mixed solution of a raw material monomer and a basic reaction aid into an oxidant solution, a method of dropping an oxidant solution into a mixed solution of a raw material monomer and a basic reaction aid, reaction Examples thereof include a method in which a mixed solution of a raw material monomer and a basic reaction aid and an oxidizing agent solution are dropped simultaneously in a container or the like.

  After the polymerization, the solvent is usually filtered off with a centrifugal separator or the like to obtain a polymer (aniline polymer).

There are cases where unreacted monomers (raw material monomers) remain in the aniline polymer thus obtained. This raw material monomer may adhere to the substrate during cleaning of an FPD substrate, a semiconductor device substrate, or the like, which causes contamination of the monomer on the substrate.
Therefore, when the raw material monomer remains in the aniline polymer, it is preferable to purify and remove the raw material monomer.
In the purified aniline-based polymer, the raw material monomer is sufficiently removed, so that it is possible to prevent monomer contamination on the substrate when used as a cleaning agent.

Examples of the purification method of the aniline polymer include a cleaning method using a solvent and a membrane filtration method.
Examples of the solvent used for the washing method include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, 2-butanol, 3-butanol, t-butanol, 1-pentanol, and 3-methyl-1-butanol. , 2-pentanol, n-hexanol, 4-methyl-2-pentanol, 2-ethylbutynol, benzyl alcohol, furfuryl alcohol, tetrahydrofurfuryl alcohol, and the like; ethylene glycol monomethyl ether, ethylene glycol monoethyl Polyhydric alcohol derivatives such as ether, methoxymethoxyethanol, propylene glycol monoethyl ether, glyceryl monoacetate; acetone; acetonitrile; N, N-dimethylformamide; N-methylpyrrole Emissions; dimethyl sulfoxide, preferably for high-purity aniline polymer is obtained. In particular, methanol, ethanol, isopropanol, acetone, and acetonitrile are effective.

When purifying an aniline polymer by a membrane filtration method, it is preferable to perform membrane filtration after dissolving the aniline polymer in a solvent.
Examples of the solvent used in the membrane filtration method include water. Water may contain one or more of basic salts, acids, and alcohols soluble in water.
As the separation membrane used in the membrane filtration method, an ultrafiltration membrane is preferable in consideration of the raw material monomer removal efficiency.
Examples of the material of the separation membrane include organic membranes using polymers such as cellulose, cellulose acetate, polysulfone, polypropylene, polyester, polyethersulfone, and polyvinylidene fluoride; inorganic materials using inorganic materials typified by ceramics A membrane can be used, and there is no particular limitation as long as it is normally used as a material for the ultrafiltration membrane.

If the washed aniline polymer is dried, a solid aniline polymer from which the raw material monomer has been sufficiently removed can be obtained.
The aniline-based polymer after membrane filtration is in a state dissolved in water. Therefore, if the water is removed with an evaporator or the like and dried, a solid aniline polymer from which the raw material monomer has been sufficiently removed can be obtained, but the aniline polymer can be used as a cleaning agent in a state dissolved in water. Good.

The content of the aniline polymer in the cleaning agent is calculated in terms of pure content (converted to solid content), preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and more preferably 1% by mass with respect to the total mass of the cleaning agent % Or more is more preferable. If the content of the aniline polymer is 0.1% by mass or more, the FPD substrate, the semiconductor device substrate and the like can be sufficiently cleaned.
The content of the aniline polymer in the cleaning agent is calculated in terms of pure content (solid content conversion), preferably 20% by mass or less, more preferably 15% by mass or less, and further preferably 10% by mass or less, based on the total mass of the cleaning agent. preferable.

<Water>
Examples of water include tap water, ion exchange water, pure water, and distilled water.
When purifying the aniline polymer by membrane filtration and using the purified aniline polymer dissolved in water, concentrate it so that the content of the aniline polymer in the cleaning agent is within the above range. Or may be diluted by adding water.

The content of water in the cleaning agent is preferably 80 to 99.9% by mass, more preferably 85 to 99.5% by mass, and still more preferably 90 to 99% by mass with respect to the total mass of the cleaning agent.
In addition, the sum total of content of the aniline polymer and water contained in a cleaning agent shall not exceed 100 mass% with respect to the total mass of a cleaning agent.

<Optional component>
The cleaning agent may contain components (optional components) other than the aniline polymer and water.
Examples of optional components include organic solvents and various additives.

The organic solvent is preferably a water-soluble organic solvent that is soluble in water. The water-soluble organic solvent is an organic solvent soluble in water, for example, alcohols such as methanol, ethanol, 2-propanol, 1-propanol and 1-butanol; ketones such as acetone, methyl ethyl ketone, ethyl isobutyl ketone and methyl isobutyl ketone Ethylene glycols such as ethylene glycol, ethylene glycol methyl ether and ethylene glycol mono-n-propyl ether; propylene glycols such as propylene glycol, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol butyl ether and propylene glycol propyl ether Amides such as dimethylformamide and dimethylacetamide; pyrrolidones such as N-methylpyrrolidone and N-ethylpyrrolidone; milk Methyl, ethyl lactate, beta-methoxyisobutyrate methyl butyrate, hydroxypropyl esters such as α- hydroxy methyl isobutyrate and the like.
1-99 mass% is preferable with respect to the total mass of a cleaning agent, as for content of the organic solvent in a cleaning agent, 3-95 mass% is more preferable, and 5-90 mass% is further more preferable.

Examples of the additive include known additives contained in cleaning agents used for cleaning FPD substrates, semiconductor device substrates, and the like. Specifically, antioxidants, rust inhibitors, pH adjusters, buffers, Examples include foaming agents, preservatives, and hydrotropes.
Note that it is preferable that the cleaning agent does not substantially contain a surfactant such as an anionic surfactant in consideration of prevention of corrosion of the metal film and prevention of foaming at the time of cleaning the FPD substrate and the semiconductor device substrate. Here, “substantially free” means 0.1 mass% or less with respect to the total mass of the cleaning agent.

  When the cleaning agent contains optional components, the total content of the aniline polymer, water and optional components contained in the cleaning agent does not exceed 100% by mass with respect to the total mass of the cleaning agent.

<Manufacturing method of cleaning agent>
The cleaning agent of the present invention can be produced by mixing the above-mentioned aniline polymer, water, and optional components as necessary.
In addition, as described above, when the aniline polymer is purified by the membrane filtration method, the purified aniline polymer is in a state dissolved in water, so the purified aniline polymer dissolved in water is used as a cleaning agent. It may be used as a cleaning agent by concentrating as necessary, diluting with water, or adding an optional component.

In the cleaning agent thus obtained, the content of the raw material monomer is sufficiently reduced. Specifically, a cleaning agent having a raw material monomer content of 500 mass ppm or less with respect to the total mass of the cleaning agent is obtained. The content of the raw material monomer is preferably 300 mass ppm or less, more preferably 250 mass ppm or less, and further preferably 200 mass ppm or less with respect to the total mass of the cleaning agent. The content of the raw material monomer in the cleaning agent is preferably as small as possible, and the lower limit is preferably 0 mass ppm.
Here, the content of the raw material monomer in the cleaning agent can be measured by ion chromatography.

<Effect>
The cleaning agent of the present invention described above contains an aniline polymer having an acidic group and water.
Since the raw material monomer (for example, aminobenzenesulfonic acid) of the aniline polymer having an acidic group is difficult to dissolve in water, when the raw material monomer is used as a cleaning agent such as an FPD substrate or a semiconductor device substrate, the raw material monomer adheres to the substrate, It causes monomer contamination on the substrate. If the cleaning agent is made alkaline, the raw material monomer is easily dissolved in water. However, if divalent metal ions (such as copper ions) are present in the water, the metal ions react with the raw material monomer and precipitate. As a result, a deposit is deposited on the substrate, which contaminates the substrate.

However, in the cleaning agent of the present invention, the content of the raw material monomer is 500 ppm by mass or less with respect to the total mass of the cleaning agent, and the content of the raw material monomer is sufficiently reduced. Therefore, the cleaning agent of the present invention can prevent monomer contamination on the substrate.
In addition, the aniline-based polymer having an acidic group contained in the cleaning agent of the present invention easily forms a chelate with a divalent metal ion such as a copper ion. Therefore, even if a divalent metal ion is present in water or the like, an aniline-based polymer having an acidic group tends to maintain a dissolved state in water and is difficult to precipitate. Therefore, contamination of the substrate can be prevented.

  Moreover, since the cleaning agent of the present invention does not need to contain a surfactant, it is hard to foam and has low corrosiveness to metals.

Further, as described above, the conventional cleaning agent has a restriction on pH during use. For example, it is considered that the cleaning agent described in Patent Document 2 needs to be adjusted to pH 6 to 11 in order to dissolve aminobenzenesulfonic acid as a monomer in water.
However, since the aniline-based polymer having an acidic group contained in the cleaning agent of the present invention is water-soluble, it can be dissolved in water without adjusting the pH. Therefore, the cleaning agent of the present invention can be used in an acidic state as well as alkaline, and there is no restriction on pH during use.

<Application>
The cleaning agent of the present invention can be used as a cleaning agent for cleaning electronic materials.
Examples of electronic materials to be cleaned (objects to be cleaned) include an FPD substrate, a semiconductor device substrate, a magnetic disk substrate, a photomask substrate, a solar cell substrate, a printed circuit board, and an electronic component. Among these, the cleaning agent of the present invention is suitable as a cleaning agent for FPD substrates and semiconductor device substrates.

For example, when the cleaning agent of the present invention is used for an FPD substrate, it is applied as a cleaning agent used in a cleaning process for the purpose of removing metal scraps and resist films generated by etching in the FPD manufacturing process. Is preferred.
When the cleaning agent of the present invention is used for a semiconductor device substrate, it should be applied as a cleaning agent used in a cleaning process for the purpose of removing metal debris and abrasives generated by CMP in a semiconductor device manufacturing process. Is preferred.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, a following example does not limit the scope of the present invention.
The various measurement / evaluation methods in Examples and Comparative Examples are as follows.

<Measurement and evaluation method>
(Measurement of content of raw material monomer)
A cleaning solution was dissolved in the following eluent to prepare a test solution. About the obtained test solution, the density | concentration of the raw material monomer was measured on the following ion chromatograph (IC) measurement conditions, and the chromatogram was obtained. The peak area or height corresponding to the raw material monomer on this chromatogram was read, and the content of the raw material monomer relative to the total mass of the detergent was determined from a calibration curve prepared in advance.
<< IC measurement conditions >>
Apparatus: Ion chromatograph IC-2010 (manufactured by Tosoh Corporation)
-Column: TSK guard Column Super IC-Anion HS C-No W00052
Eluent: A mixed solution of an aqueous sodium carbonate solution having a solid content concentration of 1.8 mmol / L and a sodium hydrogen carbonate solution having a solid content concentration of 1.7 mmol / L (mass ratio 1: 1).
・ Flow rate: 1.5 ml / min ・ Measurement temperature: 40 ° C.
-Sample injection volume: 30 μL

(Evaluation of corrosion prevention)
As a test piece, an aluminum substrate (ISO 7075-T6 equivalent product) that was previously degreased and surface-polished was used. The mass and material density of the specimen were measured.
After immersing the test piece in 100 parts by mass of the cleaning agent and holding it at 55 ° C. ± 1 ° C. for 7 days, the test piece was taken out from the cleaning agent. After removing the cleaning agent adhering to the test piece and drying the test piece, the mass of the test piece was measured. This was the mass of the test piece after immersion, and the degree of erosion of the test piece was determined from the following formula (I).
X = {(W ₁ −W ₂ ) × 10 × 365)} / (d × S × T) (I)
(In formula (I), “X” is the erosion degree [mm / year] of the test piece, “W ₁ ” is the mass [g] of the test piece before dipping in the cleaning agent, and “W ₂ ”. Is the mass [g] of the test piece after immersion, “d” is the material density [g / cm ² ] of the test piece before being immersed in the cleaning agent, and “S” is the immersion area [cm] of the test piece. ² ], and “T” is the number of immersion days (retention days).)

The corrosion resistance against metals was evaluated according to the following evaluation criteria.
○: Erosion degree is less than 6.25 mm / year.
X: Erosion degree is 6.25 mm / year or more.

(Evaluation of foaming prevention)
10 g of the cleaning agent was put into a 30 mL glass sample bottle, vigorously shaken for 30 seconds, and then left for 1 minute. The state of the foam after standing was visually observed, and the antifoaming property was evaluated according to the following evaluation criteria.
○: No bubbles can be confirmed.
X: A bubble is confirmed.

(Evaluation of monomer contamination prevention)
A silicon wafer was used as an object to be cleaned.
The object to be cleaned was immersed in 100 parts by mass of the cleaning agent and held at 25 ° C. for 2 hours, and then the object to be cleaned was taken out from the cleaning agent. After removing the cleaning agent adhering to the object to be cleaned and drying the object to be cleaned, the surface condition of the object to be cleaned was visually observed and the monomer contamination prevention property by the raw material monomer was evaluated according to the following evaluation criteria. .
A: Adherence of foreign matter cannot be confirmed.
○: A very small amount of foreign matter is confirmed.
X: The residue of a cleaning agent component is confirmed.

"Example 1"
<Production of aniline-based polymer having acidic group>
100 mmol of 2-methoxyaniline-5-sulfonic acid was dissolved in 300 mL of a 4 mol / L triethylamine solution (solvent: water / acetonitrile = 5/5) at 25 ° C. to obtain a monomer solution.
Separately, 100 mmol of ammonium peroxodisulfate was dissolved in a solution of water / acetonitrile = 5/5 to obtain an oxidant solution.
Subsequently, the oxidizing agent solution was dropped into the monomer solution. After completion of the dropwise addition, the mixture was further stirred at 25 ° C. for 12 hours, and then the reaction product was separated by a centrifugal filter. Further, the reaction product was washed with methanol and dried to obtain 15 g of a powdery polymer (poly (2-methoxyaniline-5-sulfonic acid)).

<Manufacture of cleaning agent>
2 parts by mass of poly (2-methoxyaniline-5-sulfonic acid) and 98 parts by mass of water were mixed to obtain a cleaning agent.
The content of the raw material monomer with respect to the total mass of the obtained cleaning agent was measured. The results are shown in Table 1.
Moreover, about the obtained cleaning agent, corrosion prevention property, foaming prevention property, and monomer contamination prevention property were evaluated. These results are shown in Table 1.

"Example 2"
In the same manner as in Example 1, poly (2-methoxyaniline-5-sulfonic acid) was obtained.
A cleaning agent was obtained by mixing 5 parts by mass of poly (2-methoxyaniline-5-sulfonic acid), 5 parts by mass of propylene glycol methyl ether, and 90 parts by mass of water.
The content of the raw material monomer with respect to the total mass of the obtained cleaning agent was measured. The results are shown in Table 1.
Moreover, about the obtained cleaning agent, corrosion prevention property, foaming prevention property, and monomer contamination prevention property were evaluated. These results are shown in Table 1.

"Example 3"
In the same manner as in Example 1, poly (2-methoxyaniline-5-sulfonic acid) was obtained.
8.3 parts by mass of poly (2-methoxyaniline-5-sulfonic acid), 1.7 parts by mass of propylene glycol methyl ether, and 90 parts by mass of water were mixed to obtain a cleaning agent.
The content of the raw material monomer with respect to the total mass of the obtained cleaning agent was measured. The results are shown in Table 1.
Moreover, about the obtained cleaning agent, corrosion prevention property, foaming prevention property, and monomer contamination prevention property were evaluated. These results are shown in Table 1.

"Comparative Example 1"
2 parts by mass of sulfamic acid (manufactured by Wako Pure Chemical Industries, Ltd.), 0.2 part by mass of sodium polystyrene sulfonate (manufactured by Tosoh Organic Chemical Co., Ltd., “Polynas PS-5”) as an anionic surfactant, and 97. 8 parts by mass was mixed to obtain a cleaning agent.
Table 1 shows the content of the monomer component (sulfamic acid) relative to the total mass of the obtained cleaning agent. In Comparative Example 1, the content of the monomer component was determined from the blending amount.
Moreover, about the obtained cleaning agent, corrosion prevention property, foaming prevention property, and monomer contamination prevention property were evaluated. These results are shown in Table 1.

"Comparative Example 2"
<Production of aniline-based polymer having acidic group>
100 mmol of sodium 3-aminobenzenesulfonate was dissolved in 300 mL of a 4 mol / L aqueous ammonia solution at 25 ° C. to obtain a monomer solution.
Separately, 50 mmol of ammonium peroxodisulfate was dissolved in 1 L of a solution of water / acetonitrile = 3/7 to obtain an oxidant solution.
Then, the oxidant solution was added dropwise to the monomer solution while being cooled to 5 ° C. After completion of the dropwise addition, the mixture was further stirred at 25 ° C. for 12 hours, and then the reaction product was separated by a centrifugal filter. Further, the reaction product was dried to obtain 5 g of a powdery polymer (sodium poly (3-aminobenzenesulfonate)).

<Manufacture of cleaning agent>
5 parts by mass of poly (sodium 3-aminobenzenesulfonate), 5 parts by mass of propylene glycol methyl ether, and 90 parts by mass of water were mixed to obtain a cleaning agent.
The content of the raw material monomer with respect to the total mass of the obtained cleaning agent was measured. The results are shown in Table 1.
Moreover, about the obtained cleaning agent, corrosion prevention property, foaming prevention property, and monomer contamination prevention property were evaluated. These results are shown in Table 1.

“Comparative Example 3”
2 parts by mass of sodium 3-aminobenzenesulfonate and 98 parts by mass of water were mixed to obtain a cleaning agent.
Table 1 shows the content of the monomer component (sodium 3-aminobenzenesulfonate) relative to the total mass of the obtained cleaning agent. In Comparative Example 3, the monomer component content was determined from the blending amount.
Moreover, about the obtained cleaning agent, corrosion prevention property, foaming prevention property, and monomer contamination prevention property were evaluated. These results are shown in Table 1.

  In Table 1, “content of monomer in cleaning agent” is the content (mass%) of the raw material monomer of the aniline polymer contained in the cleaning agent relative to the total mass of the cleaning agent, or blended in the cleaning agent. It is the content (mass%) of the monomer component.

As is apparent from Table 1, the cleaning agents obtained in Examples 1 to 3 had an erosion degree of less than 6.25 mm / year and low corrosiveness to metals. Moreover, the cleaning agents obtained in Examples 1 to 3 were difficult to foam. Furthermore, the cleaning agents obtained in Examples 1 to 3 were able to prevent monomer contamination on the objects to be cleaned.
As described above, the cleaning agents obtained in Examples 1 to 3 are suitable as cleaning agents for electronic materials because they are low in corrosiveness to metals, hardly foam during cleaning, and can prevent monomer contamination on the substrate.

On the other hand, the cleaning agent obtained in Comparative Example 1 was inferior in corrosion prevention and foaming prevention. Although the cleaning agent obtained in Comparative Example 1 contains 2% by mass of the monomer component (sulfamic acid), sulfamic acid is water-soluble, so it is considered that monomer contamination to the object to be cleaned could be prevented. .
The cleaning agent obtained in Comparative Example 2 had low corrosiveness to metals and was difficult to foam, but the content of the raw material monomer (sodium 3-aminobenzenesulfonate) in the cleaning agent was as high as 1000 mass ppm, and it was a monomer contamination. It was inferior in prevention.
The cleaning agent obtained in Comparative Example 3 had low corrosiveness to metals and was difficult to foam. However, since the monomer component (sodium 3-aminobenzenesulfonate) was blended as it was, the content of the monomer component in the cleaning agent was 2 It was as high as mass%, and was inferior in preventing monomer contamination.

  The cleaning agent of the present invention is useful as a cleaning agent for electronic materials such as FPD substrates and semiconductor device substrates.

Claims (3)

Containing an aniline-based polymer having an acidic group and water,
The cleaning agent whose content of the raw material monomer of the said aniline-type polymer is 500 mass ppm or less. The cleaning agent according to claim 1, wherein the aniline polymer has a unit represented by the following general formula (1).

In formula (1), R ^{1 to} R ⁴ each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 24 carbon atoms, a linear or branched alkoxy group having 1 to 24 carbon atoms, or an acidic group. , A hydroxy group, a nitro group, and a halogen atom, and at least one of R ^{1 to} R ⁴ is an acidic group. Here, the acidic group is a sulfonic acid group or a carboxy group.   The cleaning agent according to claim 1 or 2, which is for a flat panel display substrate or a semiconductor device substrate.