Conductive polymer composition, covering product, and pattern forming method

Abstract

The present invention aims to provide an electroconductive polymer composition which can be suitably used for a filter and a flat film forming property on an electron beam resist is excellent, and also shows excellent antistatic properties in an electron beam lithography process due to the property of a low volume resistivity (Ω·cm), and reduces the influence of an acid diffused from the film to a minimum to reduce the influence on lithography, and also has excellent stripping properties based on H2O or an alkaline developer after drawing for an antistatic film for electron beam lithography. The electroconductive polymer composition is characterized by containing: (A) a polyaniline-based electroconductive polymer having at least one or more repeating units represented by the following general formula (1), and (B) a carboxylic acid salt represented by the following general formula (2). [Chemical Formula 1] [Chemical Formula 2] [Chemical Formula 3]

Description

Technical Field

[0001] This invention relates to conductive polymer compositions comprising polyaniline-based conductive polymers, covers using the conductive polymer compositions, and methods for patterning. Background Technology

[0002] In the manufacturing processes of semiconductor devices such as ICs and LSIs, fine processing has traditionally been achieved using photolithography, a method that utilizes photoresist. This method involves inducing cross-linking or decomposition reactions in a thin film using light irradiation, thereby significantly altering the film's solubility. The resist pattern, obtained through solvent-based development, is then used as a mask to etch the substrate. In recent years, with the increasing integration of semiconductor devices, there has been a demand for high-precision processing using short-wavelength light beams. Electron beam photolithography, with its short-wavelength characteristics, has been developed as a next-generation technology.

[0003] One technical problem unique to electron beam lithography is the charging phenomenon during exposure (charge up). This occurs when the substrate being exposed to electron beam is covered by an insulating resist film, causing charge to accumulate on or within the resist film. Because this charging causes the trajectory of the incident electron beam to bend, the drawing accuracy is significantly reduced. Therefore, a release-type antistatic film coated on an electron beam resist is being investigated.

[0004] With the increasing refinement towards the <10nm generation, the positional accuracy of electron beam lithography for electron beam resists becomes even more critical for the aforementioned electron beam-based lithography. Regarding this etching technique, previous techniques such as high current or MBMW (multi-beam mask lighting) are under development, and the charged states on the resist are expected to further increase. Therefore, as a strategy to improve the antistatic properties of antistatic films in response to future etching technology developments, a conductive polymer with lower resistivity and higher charge dissipation capability is desired.

[0005] Patent Document 1 discloses that, in order to reduce the reduction in drawing accuracy caused by electrostatic phenomena on the resist, a π-conjugated conductive polymer with acidic substituents introduced into its structure is coated onto the resist. The resulting conductive polymer film exhibits an antistatic effect during electron beam lithography, eliminating various adverse effects caused by electrostatic phenomena, such as the adverse effects of static electricity on the positional accuracy of lithographic printing or deformation of the resist pattern during electron beam irradiation. Furthermore, it is stated that because the conductive polymer film remains water-soluble after high-dose electron beam lithography, it can be removed by washing with water.

[0006] Patent document 2 discloses a composition consisting of a polyaniline conductive polymer, a polybasic acid, and H2O. It also shows that the composite consisting of the polyaniline conductive polymer and the polybasic acid can achieve good spin-coating at 5-10% by mass, and an antistatic effect is confirmed when the film thickness is 150 nm, forming an antistatic film that can be peeled off and cleaned using H2O.

[0007] Patent document 3 discloses an antistatic film application technology for electron beam lithography of polythiophene-based conductive polymers, which shows the antistatic film function of the polythiophene-based conductive polymer and polyanionic compound due to the effect of adding gemini surfactants, etc.

[0008] Patent Document 4 proposes a compound in which at least one H atom in the benzene ring skeleton of aniline, a repeating unit of a polyaniline-based conductive polymer, is substituted with an acidic group, and self-doped within the polyaniline molecule. The polyaniline-based conductive polymers of Patent Documents 2 and 3 are complexes of aniline oligomers (π-conjugated polymers that govern charge carrier migration) and monomers or polymers with sulfonic acid ends, commonly referred to as dopants. Because these polymers exhibit particle movement and dispersion in H₂O, homogenization of the material requires high-power homogenizers or high-pressure dispersers, and the process of removing particle aggregates that form patterned defects after coating with an electron beam resist becomes complex. In contrast, the compound described in Patent Document 4, because it is solvated in H₂O and exhibits molecular movement, can drastically reduce these defect factors simply through filtration.

[0009] For compositions containing compounds that self-dope within polyaniline molecules, Patent Document 5, paragraphs 0045 to 0048, proposes a scheme to add a basic compound to the composition for the purpose of neutralizing acids, so as to avoid the acid present in the film on the electron beam resist from adversely affecting the resist pattern through interlayer diffusion during film formation. Examples of basic compounds include ammonium salts of hydroxides such as tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetrapentylammonium hydroxide, tetrahexylammonium hydroxide, and benzyltrimethylammonium hydroxide, as well as 1,5-diazabicyclo[4.3.0]-5-nonene (DBN), 1,8-diazabicyclo[5.4.0]-7-undecene (DBU), and their derivatives. However, while hydroxides are strongly basic and can neutralize acids derived from polyaniline, they also exhibit strong nucleophilicity, leading to side reactions. For example, acid-generating agents contained in EB resists typically include ester bonds as linking groups within their structure. However, these ester bonds are subject to nucleophilic attacks by hydroxyl ions, causing the sites that impart diffusion control or dissolution properties to detach. Therefore, after electron beam irradiation, the diffusion of sulfonate ions, which become small molecules, is promoted, resulting in photosensitivity fluctuations or pattern defects in lithography. On the other hand, although 1,5-diazabicyclo[4.3.0]-5-nonene (DBN) and 1,8-diazabicyclo[5.4.0]-7-undecene (DBU) are strong bases, they are considered to be weak nucleophilic and therefore unlikely to nucleophilically attack ester bonds. However, because they are small molecules, when the conductive composition is filmed on EB resist, diffusion occurs from the interface to the resist layer. After electron beam lithography, the acid generated by the acid-generating agent is quenched, resulting in problems such as photosensitivity fluctuations or pattern defects in lithography.

[0010] Existing technical documents

[0011] Patent documents

[0012] Patent Document 1: Patent Publication No. 2902727

[0013] Patent Document 2: US Patent No. 5,370,825

[0014] Patent Document 3: Japanese Patent Application Publication No. 2014-009342

[0015] Patent Document 4: Patent Publication No. 3631910

[0016] Patent Document 5: Japanese Patent Application Publication No. 2017-39927 Summary of the Invention

[0017] The technical problem to be solved by the present invention

[0018] Patent documents 1, 4, and 5 describe polyaniline compounds that incorporate acidic substituents within the π-conjugated conductive polymer monomer unit structure, with these acidic substituents self-doped into the π-conjugated conductive polymer chain. However, all the acidic substituents present within the polymer after polymerization are not doped into the π-conjugated system but exist as acids or their salts within the polymer. When in an acidic state, if this polyaniline is used as an antistatic film on an electron beam resist during electron beam irradiation, the acid diffuses into the resist layer, adversely affecting lithographic printing. Furthermore, to control the diffusion of this acid, if a strong base such as hydroxide is added as a neutralizing agent, not only is neutralization itself difficult, but unreacted strong base within the film can penetrate into the resist layer and undergo side reactions with nucleophilically attacked portions such as ester bonds in the resist composition, resulting in adverse effects on photosensitivity and lithographic printing. Furthermore, while the salt state refers to the state in which the monomer is polymerized after neutralizing the acidic groups contained in the monomer units with a strong base such as an amine before polymerization, and the product is not treated with cation exchange resins or the like, it is believed that some of the sulfonates on the polymer are acidic due to sulfuric acid, a byproduct of peroxydisulfate used as a polymerization reagent. Even after removing monomolecular impurities through purification methods such as ultrafiltration, the acid originating from the polyaniline chain will diffuse through the film formation. Therefore, when using this conductive polymer as an antistatic film for electron beam resist, additives other than strong bases must be used to control the diffusion of acid generated from the acidic ends in the polyaniline.

[0019] In tests conducted using PCD (Post Coating Delay), a method for assessing storage stability in a state where an antistatic film has formed on the resist but no electron beam irradiation has been performed, a significant effect of strong alkalis on the resist was observed. Specifically, during storage in the unirradiated state, strong alkali substances present within the antistatic film gradually penetrate and diffuse into the resist film, continuously nucleophilically attacking the resist polymer and acid-generating agents, severing the binding groups of the resist, and removing the acid terminals of the electron beam acid-generating agents. In subsequent electron beam lithography, the resist outside the depicted area continues to react, either generating small-molecule acids that react with the resist polymer at a faster diffusion rate than the original acid-generating agents. This leads to significant changes in photosensitivity, reduced film thickness, or pattern degradation in offset printing.

[0020] While polyaniline composites using unsubstituted aniline in their raw materials typically exhibit high electrical conductivity, their low hydrophilicity and poor dispersibility in H2O result in very poor film formation on substrates. In contrast, the composition described in Patent Document 2 improves the dispersibility of the polyaniline composite in H2O and its film formation on substrates by introducing various substituents into the aniline backbone of a composite consisting of a polyaniline-based conductive polymer and a polybasic acid. Even in the aforementioned electron beam lithographic printing antistatic film application, it exhibits rapid response in H2O-based peeling and cleaning processes. However, introducing substituents other than hydrogen atoms into the aniline backbone makes it difficult to impart high conductivity. That is, it is difficult to improve the reduction of resistivity, a physical property indicating antistatic performance, and in future drawing processes where a strong charged state of the resist layer as described above is expected, sufficient dispersion of charged charges cannot be adequately addressed.

[0021] Besides the aforementioned polyaniline-based conductive polymers, polythiophene-based conductive polymers, also used as π-conjugated conductive polymers in the antistatic film application process of electron beam lithography, are another type of conductive polymer. Polythiophene-based conductive polymers typically exhibit higher conductivity than polyaniline-based conductive polymers, but their affinity for H₂O is lower. Even when used as H₂O-dispersed materials, once formed into a film, they are difficult to peel off in H₂O-based stripping and cleaning processes. Even if peeled off, they cannot completely dissolve or redisperse in H₂O, instead flowing in a sheet-like or other solid state, which may cause severe pattern defects in lithography.

[0022] Patent Document 3 discloses an antistatic film application technology for electron beam lithography of polythiophene-based conductive polymers, demonstrating the antistatic film function of the polythiophene-based conductive polymer and polyanionic composite and good H2O peelability due to the effect of adding gemini surfactants, etc. Furthermore, since the composition described in Patent Document 3 uses a composite of polythiophene-based conductive polymer and polybasic acid as the base polymer, similar to the composite of polyaniline-based conductive polymer and polybasic acid described in Patent Document 2, the acidity derived from the polybasic acid may affect the resist film. To address this, the acidity is mitigated by using neutralizing agents such as amines, thereby minimizing the aforementioned impact on lithography. However, the addition of gemini surfactants and amines to mitigate acidity, intended to provide good coatability and peelability, has resulted in several issues. Firstly, the amines cause side reactions that negatively impact lithographic printing. Secondly, the surface resistivity (Ω / □), an indicator of antistatic properties, shows a relatively low value, failing to fully realize the intended antistatic effect. In conclusion, the polythiophene-based conductive polymer has failed to exhibit its inherent low resistivity. Therefore, there are concerns that it may be unable to handle sufficient charge dissipation in future painting processes requiring high antistatic properties.

[0023] Therefore, there is a need to develop an antistatic film for electron beam lithography that has good filtration properties, good film-forming properties on electron beam resist, and excellent antistatic properties in the electron beam lithography process due to its low resistivity. In order to minimize the influence of acid diffusion caused by the film, instead of using strong base-based neutralization which has an adverse effect on lithography, the diffusion rate of acid is controlled by adding carboxylic acid salts as additives and utilizing acid-salt exchange. Furthermore, the antistatic film for electron beam lithography has good peelability based on H2O or alkaline developer after application.

[0024] The present invention was made in view of the above circumstances, and its object is to provide a conductive polymer composition that is suitable for use as an antistatic film for electron beam lithography, exhibiting good film-forming properties on electron beam resist and planarity due to its low volume resistivity (Ω·cm), minimizing the influence of acid diffusion caused by the film and thus reducing the impact on lithography, and also exhibiting excellent peelability based on H2O or alkaline developer after application.

[0025] Technical means to solve technical problems

[0026] To address the aforementioned technical problems, the present invention provides a conductive polymer composition comprising:

[0027] (A) a polyaniline conductive polymer having at least one repeating unit represented by the following general formula (1), and (B) a carboxylate represented by the following general formula (2).

[0028] [Chemical Formula 1]

[0029]

[0030] In the formula, R1 to R4 each independently represent a hydrogen atom, an acidic group, a hydroxyl group, a nitro group, a halogen atom, a straight-chain or branched alkyl group with 1 to 24 carbon atoms, a straight-chain, branched, or cyclic hydrocarbon group with 1 to 24 carbon atoms containing heteroatoms, or a straight-chain, branched, or cyclic hydrocarbon group with 1 to 24 carbon atoms partially substituted by halogen atoms.

[0031] [Chemical Formula 2]

[0032]

[0033] In the formula, X + Represents lithium ions, sodium ions, potassium ions, or nitrogen compounds represented by the following general formula (3). L represents a single bond, or a straight-chain, branched, or cyclic saturated or unsaturated hydrocarbon chain with 1 to 8 carbon atoms that may contain heteroatoms. When L is a single bond, n = 0; when L is not a single bond, n = 1. R5 and R6 independently represent hydrogen atoms, heteroatoms, and -COO atoms, respectively. - X + The radical, hydroxyl group, a straight-chain, branched, or cyclic monovalent hydrocarbon group with 1 to 20 carbon atoms that can be inserted with heteroatoms, or a terminal group with -COO - X + The group consists of a straight-chain, branched, or cyclic saturated or unsaturated hydrocarbon group with 1 to 8 carbon atoms. R7 represents a hydrogen atom, a hydroxyl group, or -COO. - X + base.

[0034] [Chemical Formula 3]

[0035]

[0036] In the formula, R 101 R 102 R 103 R 104 These groups represent hydrogen atoms, linear, branched, or cyclic alkyl, alkenyl, oxoalkyl, or oxoalkenyl groups with 1 to 12 carbon atoms, aryl groups with 6 to 20 carbon atoms, or aralkyl or aryloxoalkyl groups with 7 to 12 carbon atoms, wherein some or all of the hydrogen atoms in these groups may be replaced by alkoxy groups. R 101 With R 102 R 101 With R102 and R 104 A ring can be formed; when a ring is formed, R 101 With R 102 and R 101 With R 102 and R 104 It represents an alkylene group having 3 to 10 carbon atoms, or an aromatic heterocycle having a nitrogen atom in the formula in the ring.

[0037] If the composition contains a carboxylate as represented by general formula (2) as component (B), the acidity of the polyaniline conductive polymer (A) having at least one repeating unit represented by general formula (1) can be mitigated, and the diffusion of acid to adjacent layers can be controlled.

[0038] Furthermore, the acidic group is preferably a sulfonyl group.

[0039] If the component is such as (A), the effects of the present invention can be obtained more fully.

[0040] Furthermore, the content of component (B) is preferably 1 to 70 parts by mass relative to 100 parts by mass of component (A).

[0041] If the content of component (B) is set to the above value, the diffusion of acid from the conductive film formed by the conductive polymer composition to the adjacent layers in contact can be further reduced.

[0042] Furthermore, the conductive polymer composition preferably contains (C) a nonionic surfactant.

[0043] Such a composition can improve the wettability of the conductive polymer composition to substrates and other processed materials.

[0044] Furthermore, the content of component (C) is preferably 0.1 to 10 parts by mass relative to 100 parts by mass of component (A).

[0045] Such a composition will result in better wettability on the surface of the workpiece and sufficient conductivity of the conductive film.

[0046] Furthermore, the conductive polymer composition preferably further contains (D) a water-soluble polymer.

[0047] Such a composition can improve the uniformity of the film when the conductive polymer composition is formed on a substrate or other workpiece.

[0048] Furthermore, the content of component (D) is preferably 30 to 150 parts by mass relative to 100 parts by mass of component (A).

[0049] If the content of such component (D) is high, the uniformity of the membrane can be improved, and at the same time, sufficient antistatic function can be reliably obtained.

[0050] Furthermore, the present invention provides a cover material formed by forming the above-mentioned conductive polymer composition into a film on a workpiece.

[0051] The conductive film formed from the conductive polymer composition of the present invention has excellent antistatic properties, so by covering various processed objects with such an antistatic film, high-quality coatings can be obtained.

[0052] Furthermore, the workpiece is preferably a substrate having a chemically amplified resist film.

[0053] Furthermore, the workpiece is preferably a substrate for obtaining a resist pattern by pattern irradiation with an electron beam.

[0054] Furthermore, it is preferred that the workpiece has a temperature of 20 μC / cm 2 The above-mentioned photosensitivity is achieved by using a chemically amplified electron beam resist film on a substrate.

[0055] If the conductive polymer composition of the present invention is used, it can be suitably used, especially in offset printing using electron beams, etc., and thus a resist pattern with high photosensitivity, high resolution and good pattern shape can be obtained.

[0056] Furthermore, the present invention provides a pattern forming method comprising the following steps: forming an antistatic film on a substrate having a chemically amplified resist film using the above-mentioned conductive polymer composition; irradiating the pattern with an electron beam; and developing the pattern using H2O or an alkaline developer to obtain the resist pattern.

[0057] If such a pattern formation method is used, the electron beam distortion caused by the charge on the resist surface during electron beam lithography can be prevented, and a resist pattern with high sensitivity, high resolution and good pattern shape can be obtained.

[0058] Invention Effects

[0059] If it is such a conductive polymer composition, it can be appropriately applied to an antistatic film exhibiting high-efficiency charge dissipation in the charged state during electron beam lithography, thereby improving the positional accuracy of electron beam lithography.

[0060] Furthermore, the composition containing component (A) with repeating units represented by general formula (1) and component (B) represented by general formula (2), after being deposited on a substrate, exhibits high electrical conductivity and high affinity for H2O, good filtration properties, and good planarity on electron beam resist. In addition, even in the post-deposition stripping process, stripping based on H2O or alkaline solution becomes easy. Such a composition containing component (A) and component (B) can form a conductive film with good film-forming properties and stripping properties based on H2O or alkaline solution, exhibiting high electrical conductivity, i.e., low surface resistivity (Ω / □), and providing an antistatic film with high positional accuracy in electron beam lithography against resist, good resist pattern shape, and no stripping flakes or insoluble residues on the resist pattern after resist development, which is suitable for electron beam lithography.

[0061] Furthermore, through component (B), the influence of acid diffusion from the film formed through the composition to adjacent layers can be controlled, resulting in a conductive film with high conductivity, high charge dissipation ability, and good film quality.

[0062] The composition of the present invention containing components (A) and (B) exhibits excellent peelability based on H2O or alkaline solutions after film formation. In electron beam lithography and patterning processes using electron beam resists, the film formed by this composition can be peeled off by H2O before post-drawing heat treatment. Furthermore, in the resist pattern development process after post-drawing heat treatment, it can also be peeled off by an alkaline solution (alkaline developer), similar to the elution portion of the resist pattern. Thus, film peeling based on H2O or alkaline solutions is easily performed, thereby reducing minor defects originating from film-forming material residues in the post-electron beam lithography peeling process.

[0063] Furthermore, for the composition of the present invention containing components (A) and (B), the nonionic surfactant (C) and the water-soluble polymer (D) do not hinder the peelability based on H2O or alkaline solution after film formation. The film formed by the composition containing the nonionic surfactant (C) and the water-soluble polymer (D) is easily peeled off by H2O or alkaline solution. It can be peeled off by H2O before the heat treatment after electron beam lithography. In addition, after the heat treatment after electron beam lithography, it can also be peeled off by alkaline solution (alkaline developer) in the resist pattern development process of offset printing, just like the elution part of the resist pattern. Thus, since film peeling based on H2O or alkaline solution is easy to perform, it also shows the effect of reducing extremely fine defects originating from film formation residue in the stripping process after electron beam lithography.

[0064] Furthermore, by covering various processed objects with an antistatic film formed using the conductive polymer composition of the present invention, high-quality coatings can be obtained. Detailed Implementation

[0065] As described above, there is a need for a conductive polymer composition that can form a conductive film with good coatability and film-forming properties on a substrate and good film quality, and is suitable for use in offset printing with resists such as electron beams, exhibiting excellent peelability based on H2O or alkaline solutions, high charge dissipation ability, and high conductivity, without the need for strong alkali to control the diffusion of acid generated by the film to adjacent layers.

[0066] The embodiments of the present invention will be described in detail below, but the present invention is not limited thereto.

[0067] Because the polyaniline compound, which uses only component (A) in its raw material and exhibits high conductivity, contains unconsumed sulfonyl groups during doping, its solution and even dispersion are acidic. If a liquid material using only component (A) in its raw material is used as an antistatic film on an electron beam resist during electron beam irradiation, the acid diffuses into the resist layer, adversely affecting lithographic printing. Furthermore, if a strong base such as hydroxide is added as a neutralizing agent to control the diffusion of this acid, not only is neutralization itself difficult, but when this composition is used as an antistatic film on an electron beam resist during electron beam irradiation, if there is an excess of strong base in the film, the strong base will penetrate into the resist layer and react with nucleophilically attacked sites such as ester bonds in the resist base polymer or acid-producing agent, or react with acids generated by the acid-producing agent in the resist after drawing, thus adversely affecting the drawing sensitivity and lithographic printing after development.

[0068] The inventors of this application have carefully studied the above-mentioned technical problems and found that by coating a composition of a polyaniline conductive polymer containing component (A) with repeating units represented by general formula (1) and a carboxylate of component (B) represented by general formula (2) onto a photoresist when irradiated with an electron beam, an antistatic film with good film-forming properties, film quality and film flatness can be formed, exhibiting low surface resistivity (Ω / □), i.e. high conductivity, good peelability based on H2O or alkaline solution, and the ability to suppress the diffusion of acid generated by component (A) into the photoresist.

[0069] Furthermore, it was found that by adding (C) a nonionic surfactant and (D) a water-soluble polymer or any one thereof to the above-mentioned conductive polymer dispersion, the composition containing the polyaniline conductive polymer (A) with the repeating unit represented by general formula (1) and the carboxylate of the component (B) represented by general formula (2) exhibits better wettability on the surface of the workpiece, improves film formation, and enhances film uniformity.

[0070] Furthermore, a conductive polymer composition suitable for the above-described uses of the present invention can be obtained, for example, by mixing a polyaniline polymer of component (A) with a carboxylate and solvent of component (B), and, if applicable, a surfactant of component (C) and a water-soluble polymer of component (D), and then filtering it with a filter or the like. Furthermore, a cover and substrate comprising a film formed using the conductive polymer composition of the present invention can be obtained, for example, by coating the conductive polymer composition of the present invention onto a substrate and subjecting it to heat treatment, IR irradiation, UV irradiation, or the like.

[0071] The present invention will now be described in further detail, but the invention is not limited thereto.

[0072] <Conductive Polymer Composition>

[0073] The present invention comprises (A) a polyaniline conductive polymer having at least one repeating unit represented by the following general formula (1), and (B) a conductive polymer composition comprising a carboxylate represented by the following general formula (2).

[0074] [(A) Polyaniline-based conductive polymers]

[0075] The conductive polymer composition of the present invention contains a polyaniline conductive polymer of component (A) which is a polyaniline conductive polymer having at least one repeating unit represented by the following general formula (1).

[0076] [Chemical Formula 4]

[0077]

[0078] In the formula, R1 to R4 each independently represent a hydrogen atom, an acidic group, a hydroxyl group, a nitro group, a halogen atom, a straight-chain or branched alkyl group with 1 to 24 carbon atoms, a straight-chain, branched, or cyclic hydrocarbon group with 1 to 24 carbon atoms containing heteroatoms, or a straight-chain, branched, or cyclic hydrocarbon group with 1 to 24 carbon atoms partially substituted by halogen atoms.

[0079] Polyaniline conductive polymers are π-conjugated polymers, organic polymers whose main chain is composed of aniline or aniline derivatives other than para-substituted derivatives. In this invention, component (A) is preferably a polymer containing a repeating unit (aniline monomer) represented by general formula (1) that includes at least one of R1 to R4 being a sulfonyl group. In addition, the sulfonyl group is included in the acidic group. Furthermore, as component (A), the sulfonyl group may not be present in the polymer structure, but may exhibit conductive function through doping with dopants such as acids or halide ions outside the molecule. However, considering the high affinity for H2O, high-efficiency filtration, peelability from H2O or alkaline developer after film formation, low defect rate in offset printing, ease of polymerization, low re-agglomeration during storage, and stability in air, self-doped, i.e., intramolecularly doped polyaniline conductive polymers having at least one repeating unit represented by general formula (1) are particularly effective as component (A).

[0080] The aforementioned intramolecularly doped polyaniline conductive polymer exhibits the highest conductivity when formed by aniline in which at least one of the repeating units R1 to R4 represented by the general formula (1) is substituted with a sulfonyl group. Furthermore, to enhance H2O affinity, hydrophilic substituents can be introduced into this polyaniline conductive polymer in addition to the sulfonyl groups in R1 to R4. As hydrophilic substituents, functional groups such as alkoxy, carboxyl, and hydroxyl groups can be introduced.

[0081] As a representative example of sulfonic acid-substituted aniline, aminobenzenesulfonic acid derivatives can be listed. Among the aminobenzenesulfonic acid derivatives, o-aminobenzenesulfonic acid, m-aminobenzenesulfonic acid, aniline-2,6-disulfonic acid, and aniline-3,5-disulfonic acid are preferred.

[0082] Examples of sulfonated anilines other than aminobenzenesulfonic acid include alkyl-substituted benzenesulfonic acids such as methylaminobenzenesulfonic acid, ethylaminobenzenesulfonic acid, n-propylaminobenzenesulfonic acid, isopropylaminobenzenesulfonic acid, n-butylaminobenzenesulfonic acid, sec-butylaminobenzenesulfonic acid, and tert-butylaminobenzenesulfonic acid; alkoxyaminobenzenesulfonic acids such as methoxyaminobenzenesulfonic acid, ethoxyaminobenzenesulfonic acid, and propoxyaminobenzenesulfonic acid; hydroxy-substituted aminobenzenesulfonic acids; nitro-substituted aminobenzenesulfonic acids; and halogen-substituted aminobenzenesulfonic acids such as fluoroaminobenzenesulfonic acid, chlorobenzenesulfonic acid, and bromobenzenesulfonic acid. Among these, alkoxyaminobenzenesulfonic acids and hydroxy-substituted aminobenzenesulfonic acids are suitable for use based on their H₂O affinity, conductivity, reactivity, and thermal stability of the products in the aforementioned intramolecularly doped polyaniline conductive polymers. Furthermore, these aminobenzenesulfonic acids can be used alone or in mixtures of two or more in any proportion.

[0083] Furthermore, the polyaniline conductive polymer of component (A) can also be formed by copolymerizing at least one of the repeating units R1 to R4 of the general formula (1) with a sulfonated aniline and an aniline without a sulfonated group. In this case, the affinity for H2O may sometimes decrease due to the reduced presence of sulfonated groups within the resulting polymer. To compensate for this, it is desirable to introduce substituents with a strong affinity for H2O into the aniline without a sulfonated group. It is desirable that the strongly hydrophilic substituents be functional groups such as alkoxy, carboxyl, or hydroxyl groups.

[0084] Specific examples of aniline monomers with high affinity for H2O that are desired when copolymerizing aniline without a sulfonyl group as a repeating unit include 2-methoxyaniline, 2-isopropoxyaniline, 3-methoxyaniline, 2-ethoxyaniline, 3-ethoxyaniline, 3-isopropoxyaniline, 3-hydroxyaniline, 2,5-dimethoxyaniline, 2,6-dimethoxyaniline, 3,5-dimethoxyaniline, 2,5-diethoxyaniline, 2-methoxy-5-methylaniline, 5-tert-butyl-2-methoxyaniline, 2-hydroxyaniline, and 3-hydroxyaniline.

[0085] Among them, considering the affinity for H2O, conductivity, reactivity, and thermal stability of the product, when copolymerizing with at least one sulfonated aniline monomer of R1 to R4 in general formula (1), 2-methoxyaniline, 3-methoxyaniline, 2-ethoxyaniline, 3-ethoxyaniline, 2-isopropoxyaniline, 3-isopropoxyaniline, and 3-hydroxyaniline are suitable.

[0086] [(B) carboxylates]

[0087] In the carboxylic acid salts represented by the following general formula (2), component (B) contained in the conductive polymer composition of the present invention can be a compound containing one or more carboxyl groups in the aliphatic, aromatic, cyclic aliphatic, or similar types. Furthermore, in the following general formula (2), X... + It forms salts with carboxylate ions.

[0088] [Chemical Formula 5]

[0089]

[0090] In the formula, X + Represents lithium ions, sodium ions, potassium ions, or nitrogen compounds represented by the following general formula (3). L represents a single bond, or a straight-chain, branched, or cyclic saturated or unsaturated hydrocarbon chain with 1 to 8 carbon atoms that may contain heteroatoms. When L is a single bond, n = 0; when L is not a single bond, n = 1. R5 and R6 independently represent hydrogen atoms, heteroatoms, and -COO atoms, respectively. - X +The radical, hydroxyl group, a straight-chain, branched, or cyclic monovalent hydrocarbon group with 1 to 20 carbon atoms that can be inserted with heteroatoms, or a terminal group with -COO - X + The group consists of a straight-chain, branched, or cyclic saturated or unsaturated hydrocarbon group with 1 to 8 carbon atoms. R7 represents a hydrogen atom, a hydroxyl group, or -COO. - X + base.

[0091] [Chemical Formula 6]

[0092]

[0093] In the formula, R 101 R 102 R 103 R 104 These groups represent hydrogen atoms, linear, branched, or cyclic alkyl, alkenyl, oxoalkyl, or oxoalkenyl groups with 1 to 12 carbon atoms, aryl groups with 6 to 20 carbon atoms, or aralkyl or aryloxoalkyl groups with 7 to 12 carbon atoms, wherein some or all of the hydrogen atoms in these groups may be replaced by alkoxy groups. R 101 With R 102 R 101 With R 102 and R 104 A ring can be formed; when a ring is formed, R 101 With R 102 and R 101 With R 102 and R 104 It represents an alkylene group having 3 to 10 carbon atoms, or an aromatic heterocycle having a nitrogen atom in the formula in the ring.

[0094] In terms of operation, component (B) is preferred to have high water solubility. Furthermore, from the perspective of conductivity when combined with component (A) to form a composition of polyaniline-based conductive polymer, dispersibility in the composition, and dispersibility within the film after film formation, the molecular weight of the carboxylic acid is preferably 250 or less.

[0095] As represented by general formula (2) X +Representative examples of carboxylic acids that form salts include formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, neovaleric acid, 2-methylbutyric acid, isovaleric acid, hexanoic acid, 2-methylvaleric acid, 3-methylvaleric acid, 4-methylvaleric acid, 2,2-dimethylbutyric acid, 2,3-dimethylbutyric acid, 3,3-dimethylbutyric acid, 2-ethylbutyric acid, heptanoic acid, octanoic acid, methacrylic acid, crotonic acid, isoctanoic acid, benzoic acid, oxalic acid, malonic acid, fumaric acid, succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, lactic acid, pyruvic acid, tartaric acid, citric acid, isocitrate, aspartic acid, glutamic acid, chloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, nitroacetic acid, triphenylacetic acid, etc.

[0096] [Other ingredients]

[0097] (surfactant)

[0098] To improve the wettability to substrates and other workpieces, a surfactant may be added in this invention. Various nonionic, cationic, and anionic surfactants can be listed as such surfactants, but from the perspective of the stability of conductive polymers, (C) nonionic surfactants are particularly preferred. Specifically, suitable examples include nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene carboxylate esters, sorbitan esters, and polyoxyethylene sorbitan anhydride esters; cationic surfactants such as alkyltrimethylammonium chloride and alkylbenzylammonium chloride; anionic surfactants such as alkyl or alkyl allyl sulfates, alkyl or alkyl allyl sulfonates, and dialkyl sulfosuccinates; and amphoteric surfactants such as amino acid-type and betaine-type surfactants.

[0099] Such a composition can improve the wettability of the conductive polymer composition to substrates and other processed materials.

[0100] (Water-soluble polymer)

[0101] Furthermore, to improve the uniformity of the film when formed on a substrate or other workpiece, the present invention may further add (D) a water-soluble polymer. Such a water-soluble polymer is preferably a homopolymer or copolymer of hydrophilic repeating units. Moreover, it is preferable that such hydrophilic repeating units have vinyl groups on their polymeric functional groups, and further, in the sense of controlling the diffusion of acid generated by component (A), compounds containing nitrogen atoms within the molecule are preferred. In this case, as long as the nitrogen atom within the molecule is not nucleophilic, there is no need to worry about side reactions occurring with the ester groups contained in the resist polymer or acid-generating agent in the resist composition, as described above, due to nucleophilic attack on functional groups, which is therefore more preferable. Therefore, as the repeating unit, nitrogen-containing heterocyclic compounds are more desirable than compounds with nitrogen atoms at the ends, such as acrylamides. Furthermore, it is more preferable that the nitrogen atom is bonded to an alkenyl group in the main chain forming the cyclic structure. Examples of such repeating units include N-vinyl-2-pyrrolidone and N-vinylcaprolactam.

[0102] Such a composition can improve the uniformity of the film when the conductive polymer composition is formed on a substrate or other workpiece.

[0103] <Preparation Methods of Polyaniline-Based Conductive Polymers>

[0104] Patent document 4 (Patent Publication No. 3631910) discloses a self-doped sulfonated polyaniline that exhibits conductivity without forming a complex with dopants or polymer dopants, and its synthesis method. Many previous polyaniline materials, although doped, were almost insoluble in all organic solvents. Even with H2O as the solvent, the solubility of the purified polymer was generally low. Even if polymer dopants were used to disperse it in H2O, it would still be particulate. Therefore, in applications such as mounting as transparent films in electronic devices or forming semiconductor-related thin films, it was difficult to remove the agglomerates of particles, which could be a major cause of defects. Furthermore, in filtration purification, which is commonly used for polymer purification, the agglomerates are filtered out, leading to changes in the solid composition. Moreover, there are limitations to reducing the pore size of filters, posing problems for stable manufacturing.

[0105] When component (A) used in this invention is a self-doped polyaniline, for example, the repeating unit represented by the above general formula (1) (i.e., component (A)) can be obtained by adding an oxidizing agent to an aqueous solution or a mixture of water and an organic solvent and then performing oxidative polymerization. The polymerization method for component (A) can be any known method and is not particularly limited. Specifically, the monomer used to obtain the repeating unit represented by general formula (1) can be polymerized by various synthesis methods such as chemical oxidation and electrolytic oxidation. For example, the methods described in Patent Publication No. 3154460 and Patent Publication No. 2959968 can be used.

[0106] Thus, the polyaniline conductive polymer of component (A) generated by the above polymerization method is soluble in H2O and organic solvents due to its molecular properties, making it easy to filter and purify. In addition, it reduces the formation of aggregates, which are the main cause of defects, and improves the removal efficiency based on filtration.

[0107] As a polymerization initiator for the polymerization of component (A), persulfates such as ammonium persulfate, sodium persulfate, and potassium persulfate, as well as peroxides such as hydrogen peroxide and ozone, organic peroxides such as benzoyl peroxide, and oxygen can be used.

[0108] As the reaction solvent used in oxidative polymerization, water or a mixture of water and solvent can be used. Preferably, the solvent used here is miscible with water and can dissolve or disperse components (A) and (B). Examples include alcohols such as methanol, ethanol, propanol, and butanol; polyaliphatic alcohols such as ethylene glycol, propylene glycol, 1,3-propanediol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, D-glucose, D-glucanol, isopentyl glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,9-nonanediol, and neopentanediol; chain ethers such as dialkyl ethers, ethylene glycol monoalkyl ethers, ethylene glycol dialkyl ethers, propylene glycol monoalkyl ethers, propylene glycol dialkyl ethers, polyethylene glycol dialkyl ethers, and polypropylene glycol dialkyl ethers; cyclic ether compounds such as dioxane and tetrahydrofuran; and cyclohexanone, methylpentyl ketone, ethyl acetate, and butanediol monomethyl ether. Polar solvents such as ethers, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, butanediol monoethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, propylene glycol monotert-butyl ether acetate, γ-butyrolactone, N-methyl-2-pyrrolidone, N,N'-dimethylformamide, N,N'-dimethylacetamide, dimethyl sulfoxide, and hexamethylenetetramine; carbonate compounds such as ethylene carbonate and propylene carbonate; heterocyclic compounds such as 3-methyl-2-oxazolidinone; and nitrile compounds such as acetonitrile, glutaronitrile, methoxyacetonitrile, propionitrile, and benzonitrile. These solvents can be used alone or in mixtures of two or more. The amount of these water-miscible solvents incorporated is preferably less than 50% by mass of the total reaction solvent.

[0109] The polymerization of polyaniline-based conductive polymers of component (A) can be carried out by dissolving the monomer used to obtain the repeating unit represented by the above general formula (1) in a solvent and adding a polymerization initiator dropwise. When the solubility of the monomer is low, the initial concentration is sometimes low in order to form a homogeneous reaction system. This reduction in initial concentration will cause the polymerization reaction to weaken, and the resulting polymer will not have the molecular weight required to have sufficient conductivity or film-forming properties. Therefore, in order to sufficiently increase the initial concentration of the monomer during polymerization, it is desirable to add a base to the monomer to form a salt with the sulfonyl group in the monomer, thereby increasing the solubility and carrying out polymerization.

[0110] The initial concentration of the monomer used to obtain the repeating unit of general formula (1) during polymerization is preferably 1.0 to 2.0 mol / L, and more preferably 1.5 to 1.8 mol / L.

[0111] More preferably, the repeating unit represented by the above general formula (1) is subjected to oxidative polymerization in the presence of an oxidant. The sulfonyl group in the monomer used to obtain the repeating unit of general formula (1) in the polymerization forms a salt by the above-mentioned alkali. The acidity of the solution at this time is preferably pH < 7.0.

[0112] Furthermore, during the above polymerization, in an aqueous solution or a mixed solution of water and an organic solvent, an organic cation represented by the following general formula (4), or an ion of an alkali metal or alkaline earth metal, which is a coexisting base, is used to form a salt with the acidic group in the repeating unit of general formula (1).

[0113] The organic cation represented by the following general formula (4) is preferably an organic cation generated by contacting ammonia, aliphatic amines, cyclic saturated amines, or cyclic unsaturated amines with an acid.

[0114] [Chemical Formula 7]

[0115]

[0116] In the formula, R 201 R 202 R 203 R 204 These groups represent hydrogen atoms, linear, branched, or cyclic alkyl, alkenyl, oxoalkyl, or oxoalkenyl groups with 1 to 12 carbon atoms, aryl groups with 6 to 20 carbon atoms, or aralkyl or aryloxoalkyl groups with 7 to 12 carbon atoms, wherein some or all of the hydrogen atoms in these groups may be replaced by alkoxy groups. R 201 With R 202 R 201 With R 202 and R 204 A ring can be formed; when a ring is formed, R 201 With R 202 and R 201 With R202 and R 204 It represents an alkylene group having 3 to 10 carbon atoms, or an aromatic heterocycle having a nitrogen atom in the formula in the ring.

[0117] The polyaniline-based conductive polymer of component (A) polymerized in this manner is separated as a precipitate in the reaction solution by filtration. As a filtration method, vacuum filtration, pressure filtration, centrifugation, and centrifugal filtration can be used, but considering the simplicity of the method and its adaptability to large-scale synthesis, vacuum filtration is more suitable, as the precipitate can be washed with a weak solvent on a funnel.

[0118] Furthermore, the polyaniline conductive polymer of component (A) obtained in this manner can be redissolved in H2O after drying and impurities can be removed by methods such as ultrafiltration.

[0119] Ultrafiltration methods include pressurized and cross-flow methods, but from the perspective of productivity and the scale of purified materials, cross-flow is preferred. Furthermore, even within the cross-flow method, depending on the approach, there are continuous circulation (purification is time-controlled, with appropriate solvent additions during the purification process to address the high viscosity caused by the concentration of the original solution) and sequential processing (dilution is performed at the point where the original solution is concentrated to twice its original concentration, and this process is repeated until the target purity is achieved). Both methods can be used for processing.

[0120] Furthermore, the membrane structures used in ultrafiltration include flat membranes, hollow fiber membranes, tubular membranes, and spiral membranes. The materials used for separation membranes include cellulose, cellulose acetate, polysulfone, polypropylene, polyester, polyethersulfone, and polyvinylidene fluoride. In this process, any combination of these materials can be used without restriction. However, when the solvent for purifying the material is H2O or an acidic solution, a separation membrane made of polyethersulfone is preferred. From the perspective of the scale of the treated liquid and the treatment efficiency, hollow fiber membranes are the preferred membrane structure.

[0121] Given that the substances removed in the ultrafiltration process are small molecules of unreacted substances or polymerization byproducts, the molecular weight cutoff of the membrane is preferably in the range of 1,000 to 150,000, and more preferably in the range of 5,000 to 30,000.

[0122] Furthermore, at this point, considering that the purified stock solution is concentrated to twice its original concentration and the efficiency of dialysis based on the filtration membrane, the stock solution concentration is preferably 0.5 to 1.5 by weight.

[0123] In ultrafiltration, when purification is performed using a cross-flow successive process, impurity ions in the filtrate can be quantified using ion chromatography at each stage. The ions that can be quantified in this analysis include SO42-. 2- NH4+ Na + While other ions can also serve as suitable quantitative targets, SO4 at the end of ultrafiltration purification is another example. 2- NH4 + Na + The concentration is preferably below 10 ppm, and more preferably below 1 ppm.

[0124] Although the polyaniline conductive polymer (component A) purified by ultrafiltration is an H2O solution at the end of the purification process, it can be further purified by precipitation using a weak, water-soluble solvent such as acetone. The precipitated polyaniline conductive polymer (component A) is then filtered under reduced pressure, and the filtered precipitate can be washed again with a weak solvent.

[0125] <Preparation Method of Conductive Polymer Composition>

[0126] The conductive polymer composition suitable for use in the above-described applications of the present invention can be obtained, for example, by mixing a polyaniline polymer of component (A) with a carboxylate and solvent of component (B), and further, if applicable, a nonionic surfactant of component (C) and a water-soluble polymer of component (D), and then filtering it with a filter or the like.

[0127] At this point, given that the polyaniline conductive polymer of component (A), the carboxylate of component (B), and, further depending on the circumstances, the nonionic surfactant of component (C) and the water-soluble polymer of component (D) are all dissolved, and considering the effect of the electron beam resist being stripped or mixed on the substrate on which the film is formed on the resist lithography, H2O is preferably used as the main solvent.

[0128] The amount of solid component (A) in the composition varies depending on the charge dissipation and film thickness required by the electron beam resist antistatic film, but is preferably 0.05 to 1.0 wt% in view of the high stripping efficiency during stripping or development immediately after electron beam lithography, and more preferably 0.1 to 0.3 wt%.

[0129] Furthermore, at this time, the content of component (B) is preferably 1 to 70 parts by mass relative to 100 parts by mass of component (A). Further, the content of component (B) is preferably 3 to 40 parts by mass relative to 100 parts by mass of component (A), and even more preferably 5 to 30 parts by mass. Additionally, the content of component (B) can be 10 to 70 parts by mass, or 10 to 50 parts by mass relative to 100 parts by mass of component (A).

[0130] If the contents of components (A) and (B) are set within the above range, acid diffusion from the conductive film formed by the conductive polymer composition to adjacent contact layers can be further reduced. When the workpiece formed from such a conductive film is a substrate with a chemically amplified resist film, and the purpose is to achieve antistatic effects during electron beam lithography, in addition to the conductive film exhibiting antistatic effects and enabling high-precision marking, the influence of acid diffusion from the conductive film to the resist is reduced, resulting in high-resolution resist patterns.

[0131] Furthermore, when (C) nonionic surfactant is added, its content is preferably 0.1 to 10 parts by mass relative to 100 parts by mass of component (A), and more preferably 0.5 to 5 parts by mass.

[0132] Furthermore, when water-soluble polymer (D) is added, its content relative to 100 parts by mass of component (A) is preferably 30 to 150 parts by mass, and more preferably 90 to 120 parts by mass.

[0133] If the conductive polymer composition described above is used, it can form a suitable antistatic film with good filterability and coatability in electron beam lithography.

[0134] The conductive polymer composition obtained in this way can be coated onto workpieces such as electron beam resists or even substrates using various methods to form an antistatic film. Specifically, methods include coating using spin coaters, rod coating, dip coating, comma coating, spraying, roller coating, screen printing, aniline printing, gravure printing, and inkjet printing. After coating, heat treatment using hot air circulating ovens, heating plates, IR irradiation, or UV irradiation can be performed to form a conductive film.

[0135] Furthermore, the conductive polymer composition of the present invention can be suitably used not only as an antistatic film related to offset printing, but also as a material for forming laminated films as a device component in organic thin-film devices. Furthermore, due to its excellent conductivity, film-forming properties, and transparency, it can also be suitably used as an electrode film forming material for transparent electrodes in organic EL displays, organic EL lighting, solar cells, etc., or, due to its high-efficiency carrier migration characteristics originating from a π-conjugated network, it can also be suitably used as a carrier migration film forming material for carrier injection layers, carrier migration layers, etc., in organic EL displays, organic EL lighting, solar cells, etc.

[0136] When component (B) is used in the conductive polymer composition of the present invention, it will not cause adverse effects of acid on adjacent layers in the stacked structure when used as a forming layer in the multilayer structure of the organic thin film device. Therefore, after the device is constructed, side reactions and deterioration caused by deterioration of the structural materials at the interface of adjacent layers or acid can be avoided.

[0137] <Covering>

[0138] Furthermore, the present invention provides a coating made from the conductive polymer composition of the present invention, which forms a film on a workpiece. Because the conductive film formed from the conductive polymer composition of the present invention has excellent antistatic properties, high-quality coatings can be obtained by covering various workpieces with such an antistatic film.

[0139] Examples of substrates that can be processed include glass substrates, quartz substrates, photomask blank substrates, resin substrates, silicon wafers, gallium arsenide wafers, indium phosphide wafers and other compound semiconductor wafers, as well as flexible substrates such as resin films, ultra-thin film glass, and metal foils. For the purposes of planarization or insulation, and to prevent the permeation of gas and moisture, organic or inorganic thin film layers can be further coated on the surface of these substrates.

[0140] Examples of covers that are coated with a conductive film obtained by using the conductive polymer composition of the present invention include glass substrates, resin films, and photoresist substrates coated with the conductive polymer composition of the present invention for use as antistatic films.

[0141] Furthermore, the conductive polymer composition of the present invention is suitable for use in separate antistatic film stripping steps or antistatic film stripping steps included in the development process of electron beam lithography. Therefore, it can be suitably used even when the workpiece is a substrate having a chemically amplified resist film. Even more suitable results can be obtained when the workpiece is a substrate used to obtain resist patterns by patterning with an electron beam. In addition, the workpiece can also have a resist film with a temperature of 20 μC / cm². 2 The above-mentioned photosensitivity is achieved by using a chemically amplified electron beam resist film on a substrate.

[0142] <Pattern Formation Method>

[0143] Furthermore, the present invention provides a pattern forming method comprising the following steps: forming an antistatic film on a substrate having a chemically amplified resist film using the conductive polymer composition of the present invention; irradiating the pattern with an electron beam; and developing the pattern using H2O or an alkaline developer to obtain the resist pattern.

[0144] In addition to using the conductive polymer composition of the present invention, the above-described pattern formation method can be carried out according to conventional methods. The antistatic film formed by the conductive polymer composition can be stripped off by H2O after electron beam lithography and before heat treatment, or it can be stripped off by a developer during the resist pattern development process after heat treatment. Of course, etching or other various processes can also be performed after resist pattern development.

[0145] This pattern-forming method can prevent electrical charge during exposure, resulting in patterns with high sensitivity, high resolution, and good shape.

[0146] Example

[0147] The present invention will now be specifically described using manufacturing examples, embodiments, and comparative examples, but the present invention is not limited thereto.

[0148] Synthesis of self-doped polyaniline-based conductive polymers

[0149] In the polyaniline-based conductive polymer of component (A) used in this invention, from the perspectives of solubility, conductivity, and raw material cost, it is particularly preferred to polymerize methoxyaminobenzenesulfonic acids individually, especially 3-amino-4-methoxybenzenesulfonic acid, in the aforementioned repeating units. Furthermore, from the perspectives of operation, cost, alkalinity, and harmlessness to the resist components, pyridine is preferably the coexisting base during polymerization. Since it is also included in the polymer as a residual ion after polymerization and formation, the impact on lithographic printing can be minimized when this composition is coated onto an electron beam resist.

[0150] (Preparation Example) Synthesis of Polyaniline-based Conductive Polymers

[0151] 114.1 g of ammonium persulfate was dissolved in 400 ml of an acetonitrile / H₂O mixture (acetonitrile / H₂O = 1 / 1) and cooled to 0°C. Under these conditions, a solution prepared by completely dissolving 101.6 g of 3-amino-4-methoxybenzenesulfonic acid in 300 ml of an acetonitrile / H₂O mixture (acetonitrile / H₂O = 1 / 1) in 2 mol / L pyridine and cooling to 0°C was added dropwise at a rate of 1.5 ml / min. After the entire addition was completed, the reaction system was heated to 25°C and stirred for 12 hours. After stirring, the precipitate was obtained by filtration through a Kiriyama funnel, washed with methanol, and dried to obtain 45 g of powdered conductive polymer. The obtained conductive polymer was redissolved in H₂O to a concentration of 1.0 wt%, and purified by ultrafiltration (hollow fiber type, MWCO = 1000) until the NH₄⁺ in the dialysate was reduced. + SO4 2- Ion concentration < 1.0 ppm. Ultrafiltration conditions are as follows.

[0152] Ultrafiltration membrane molecular weight cutoff: 10K

[0153] Cross-flow

[0154] Liquid supply flow rate: 3,000 mL / min

[0155] Membrane partial pressure: 0.12 Pa

[0156] The purified solution was concentrated and added dropwise to 4,000 mL of acetone to obtain a powder. The powder was then redispersed in 2,000 mL of ultrapure water and added dropwise to 4,000 mL of acetone to allow recrystallization. The powder was then dried to obtain a brown conductive polymer.

[0157] Ultrafiltration can be performed using either a continuous circulation method (purification is controlled by time, with appropriate solvent added for dilution during the purification process to address the high viscosity caused by the concentration of the original solution) or a sequential process method (dilution is performed at the point where the original solution is concentrated to twice its original concentration, and this process is repeated until the target purity is achieved). To observe the progression of impurity ion removal during the purification process, a sequential process method can be used. In the sequential process purification, the concentration of impurity ions in the discharged dialysate was quantitatively analyzed using ion chromatography, and the results are shown in Table 1.

[0158] [Table 1] [ppm]

[0159] sample <![CDATA[SO4 2+ ]]> <![CDATA[Na + ]]> <![CDATA[NH4 + ]]> First process 630 0.4 200 Second process 440 0.1 150 Third process 220 <0.1 74 Fourth process 95 <0.1 29 Fifth process 29 <0.1 9.0 Sixth process 6.1 <0.1 2.7 Seventh process 1.0 <0.1 1.0 Eighth process 0.5 <0.1 0.9 Ninth process 0.3 <0.1 0.8 Tenth process 0.2 <0.1 0.7

[0160] [Preparation of conductive polymer compositions containing polyaniline-based conductive polymers]

[0161] (Example 1)

[0162] 1.00 g of the brown powder of the polyaniline conductive polymer obtained in the preparation example was dissolved in ultrapure water containing 0.051 g of ammonium acetate to prepare the polymer with a solid component concentration of 0.20 wt%. After stirring at room temperature for 2 hours, the mixture was filtered through a hydrophilic polyethylene filter as Example 1.

[0163] (Example 2)

[0164] Except for replacing the ammonium acetate in Example 1 with 0.088 g of tetramethylammonium acetate, the conductive polymer composition was prepared in the same manner as in Example 1 to obtain a conductive polymer composition.

[0165] (Example 3)

[0166] Except that the ammonium acetate in Example 1 was replaced with 0.200 g of tetra-n-butylacetic acid ammonium, the conductive polymer composition was prepared in the same manner as in Example 1 to obtain the conductive polymer composition.

[0167] (Example 4)

[0168] Except for replacing the ammonium acetate in Example 1 with 0.072 g of sodium methacrylate, the conductive polymer composition was prepared in the same manner as in Example 1 to obtain a conductive polymer composition.

[0169] (Example 5)

[0170] Except for replacing the ammonium acetate in Example 1 with 0.096g of sodium benzoate, the conductive polymer composition was prepared in the same manner as in Example 1 to obtain a conductive polymer composition.

[0171] (Example 6)

[0172] Except for replacing the ammonium acetate in Example 1 with 0.092g of ammonium benzoate, the conductive polymer composition was prepared in the same manner as in Example 1 to obtain a conductive polymer composition.

[0173] (Example 7)

[0174] Except that the ammonium acetate in Example 1 was replaced with 0.24 g of tetra-n-butylbenzoate, the conductive polymer composition was prepared in the same manner as in Example 1 to obtain the conductive polymer composition.

[0175] (Example 8)

[0176] Except for replacing the ammonium acetate in Example 1 with 0.045g of sodium oxalate, the conductive polymer composition was prepared in the same manner as in Example 1 to obtain a conductive polymer composition.

[0177] (Example 9)

[0178] Except for replacing ammonium acetate in Example 1 with 0.047g of ammonium oxalate, the conductive polymer composition was prepared in the same manner as in Example 1 to obtain a conductive polymer composition.

[0179] (Example 10)

[0180] Except for replacing the ammonium acetate in Example 1 with 0.054 g of sodium succinate, the conductive polymer composition was prepared in the same manner as in Example 1 to obtain a conductive polymer composition.

[0181] (Example 11)

[0182] Except for replacing the ammonium acetate in Example 1 with 0.080 g of dipotassium phthalate, the conductive polymer composition was prepared in the same manner as in Example 1 to obtain a conductive polymer composition.

[0183] (Example 12)

[0184] Except for replacing the ammonium acetate in Example 1 with 0.065g of trisodium citrate, the conductive polymer composition was prepared in the same manner as in Example 1 to obtain a conductive polymer composition.

[0185] (Example 13)

[0186] Except for replacing the ammonium acetate in Example 1 with 0.054g of triammonium citrate, the conductive polymer composition was prepared in the same manner as in Example 1 to obtain a conductive polymer composition.

[0187] (Example 14)

[0188] In ultrapure water containing 0.051 g of ammonium acetate, 0.03 g of acetylene glycol surfactant SURFYNOL 465 (manufactured by Nissin Chemical Co., Ltd.) as a nonionic surfactant was dissolved, and 1.00 g of brown powder of the polyaniline conductive polymer obtained in the preparation example was further dissolved to achieve a solid content concentration of 0.20 wt%. After stirring at room temperature for 2 hours, the mixture was filtered through a hydrophilic polyethylene filter as Example 14.

[0189] (Example 15)

[0190] Except that the ammonium acetate in Example 14 was replaced with 0.088 g of tetramethylammonium acetate, the conductive polymer composition was prepared in the same manner as in Example 14 to obtain the conductive polymer composition.

[0191] (Example 16)

[0192] Except that the ammonium acetate in Example 14 was replaced with 0.200 g of tetra-n-butylacetic acid ammonium, the conductive polymer composition was prepared in the same manner as in Example 14 to obtain the conductive polymer composition.

[0193] (Example 17)

[0194] Except for replacing the ammonium acetate in Example 14 with 0.072 g of sodium methacrylate, the conductive polymer composition was prepared in the same manner as in Example 14 to obtain the conductive polymer composition.

[0195] (Example 18)

[0196] Except for replacing the ammonium acetate in Example 14 with 0.096 g of sodium benzoate, the conductive polymer composition was prepared in the same manner as in Example 14 to obtain the conductive polymer composition.

[0197] (Example 19)

[0198] Except for replacing the ammonium acetate in Example 14 with 0.092 g of ammonium benzoate, the conductive polymer composition was prepared in the same manner as in Example 14 to obtain the conductive polymer composition.

[0199] (Example 20)

[0200] Except that the ammonium acetate in Example 14 was replaced with 0.24 g of tetra-n-butylbenzoate, the conductive polymer composition was prepared in the same manner as in Example 14 to obtain the conductive polymer composition.

[0201] (Example 21)

[0202] Except for replacing the ammonium acetate in Example 14 with 0.045 g of sodium oxalate, the conductive polymer composition was prepared in the same manner as in Example 14 to obtain the conductive polymer composition.

[0203] (Example 22)

[0204] Except that the ammonium acetate in Example 14 was replaced with 0.047 g of ammonium oxalate, the conductive polymer composition was prepared in the same manner as in Example 14 to obtain the conductive polymer composition.

[0205] (Example 23)

[0206] Except for replacing the ammonium acetate in Example 14 with 0.054 g of sodium succinate, the conductive polymer composition was prepared in the same manner as in Example 14 to obtain the conductive polymer composition.

[0207] (Example 24)

[0208] Except for replacing the ammonium acetate in Example 14 with 0.080 g of dipotassium phthalate, the conductive polymer composition was prepared in the same manner as in Example 14 to obtain the conductive polymer composition.

[0209] (Example 25)

[0210] Except for replacing the ammonium acetate in Example 14 with 0.065 g of trisodium citrate, the conductive polymer composition was prepared in the same manner as in Example 14 to obtain the conductive polymer composition.

[0211] (Example 26)

[0212] Except that the ammonium acetate in Example 14 was replaced with 0.054 g of triammonium citrate, the conductive polymer composition was prepared in the same manner as in Example 14 to obtain the conductive polymer composition.

[0213] (Example 27)

[0214] In ultrapure water containing 0.051 g of ammonium acetate, 0.03 g of acetylene glycol surfactant SURFYNOL 465 (manufactured by Nissin Chemical Co., Ltd.) as a nonionic surfactant and 0.90 g of polyvinylpyrrolidone (manufactured by Nacalai Corporation) as a water-soluble polymer were dissolved, and 1.00 g of the brown powder of the polyaniline conductive polymer obtained in the preparation example was further dissolved to achieve a solid content concentration of 0.200 wt%. After stirring at room temperature for 2 hours, the mixture was filtered through a hydrophilic polyethylene filter as Example 27.

[0215] (Example 28)

[0216] Except for replacing the ammonium acetate in Example 27 with 0.088 g of tetramethylammonium acetate, the conductive polymer composition was prepared in the same manner as in Example 27 to obtain the conductive polymer composition.

[0217] (Example 29)

[0218] Except for replacing the ammonium acetate in Example 27 with 0.20 g of tetra-n-butylacetic acid, the conductive polymer composition was prepared in the same manner as in Example 27 to obtain a conductive polymer composition.

[0219] (Example 30)

[0220] Except for replacing the ammonium acetate in Example 27 with 0.072 g of sodium methacrylate, the conductive polymer composition was prepared in the same manner as in Example 27 to obtain the conductive polymer composition.

[0221] (Example 31)

[0222] Except for replacing the ammonium acetate in Example 27 with 0.096 g of sodium benzoate, the conductive polymer composition was prepared in the same manner as in Example 27 to obtain the conductive polymer composition.

[0223] (Example 32)

[0224] Except for replacing the ammonium acetate in Example 27 with 0.092 g of ammonium benzoate, the conductive polymer composition was prepared in the same manner as in Example 27 to obtain the conductive polymer composition.

[0225] (Example 33)

[0226] Except for replacing the ammonium acetate in Example 27 with 0.24 g of tetra-n-butylbenzoate, the conductive polymer composition was prepared in the same manner as in Example 27 to obtain the conductive polymer composition.

[0227] (Example 34)

[0228] Except for replacing the ammonium acetate in Example 27 with 0.045 g of sodium oxalate, the conductive polymer composition was prepared in the same manner as in Example 27 to obtain the conductive polymer composition.

[0229] (Example 35)

[0230] Except for replacing the ammonium acetate in Example 27 with 0.047 g of ammonium oxalate, the conductive polymer composition was prepared in the same manner as in Example 27 to obtain the conductive polymer composition.

[0231] (Example 36)

[0232] Except for replacing the ammonium acetate in Example 27 with 0.054 g of sodium succinate, the conductive polymer composition was prepared in the same manner as in Example 27 to obtain the conductive polymer composition.

[0233] (Example 37)

[0234] Except for replacing the ammonium acetate in Example 27 with 0.080 g of dipotassium phthalate, the conductive polymer composition was prepared in the same manner as in Example 27 to obtain the conductive polymer composition.

[0235] (Example 38)

[0236] Except for replacing the ammonium acetate in Example 27 with 0.065 g of trisodium citrate, the conductive polymer composition was prepared in the same manner as in Example 27 to obtain the conductive polymer composition.

[0237] (Example 39)

[0238] Except for replacing the ammonium acetate in Example 27 with 0.054 g of triammonium citrate, the conductive polymer composition was prepared in the same manner as in Example 27 to obtain the conductive polymer composition.

[0239] (Comparative Example 1)

[0240] 1.00 g of brown powder of polyaniline conductive polymer obtained in the preparation example was dissolved in ultrapure water containing 0.067 g of triethylamine, so that the concentration of the solid component of the polymer was 0.20 wt%. After stirring at room temperature for 2 hours, the mixture was filtered through a hydrophilic polyethylene filter as Comparative Example 1.

[0241] (Comparative Example 2)

[0242] In ultrapure water containing 0.17 g of tetra-n-butylammonium hydroxide, 1.00 g of brown powder of polyaniline conductive polymer obtained in the preparation example was dissolved to make the concentration of the solid component of the polymer 0.20 wt%. After stirring at room temperature for 2 hours, the mixture was filtered through a hydrophilic polyethylene filter as Comparative Example 2.

[0243] (Comparative Example 3)

[0244] In ultrapure water containing 0.10 g of diazabicycloundecene (DBU), 1.00 g of brown powder of the polyaniline conductive polymer obtained in the preparation example was dissolved to make the concentration of the solid component of the polymer 0.20 wt%. After stirring at room temperature for 2 hours, the mixture was filtered through a hydrophilic polyethylene filter as Comparative Example 3.

[0245] (Comparative Example 4)

[0246] In ultrapure water containing 0.067 g of triethylamine, 0.03 g of acetylene glycol surfactant SURFYNOL 465 (manufactured by Nissin Chemical Co., Ltd.) as a nonionic surfactant was dissolved, and 1.00 g of brown powder of the polyaniline conductive polymer obtained in the preparation example was further dissolved to achieve a solid content concentration of 0.20 wt%. After stirring at room temperature for 2 hours, the mixture was filtered through a hydrophilic polyethylene filter as Comparative Example 4.

[0247] (Comparative Example 5)

[0248] In ultrapure water containing 0.17 g of tetra-n-butylammonium hydroxide, 0.03 g of acetylene glycol surfactant SURFYNOL 465 (manufactured by Nissin Chemical Co., Ltd.) as a nonionic surfactant was dissolved, and further 1.00 g of brown powder of the polyaniline conductive polymer obtained in the preparation example was dissolved to achieve a solid content concentration of 0.20 wt%. After stirring at room temperature for 2 hours, the mixture was filtered through a hydrophilic polyethylene filter as Comparative Example 5.

[0249] (Comparative Example 6)

[0250] In ultrapure water containing 0.10 g of diazabicycloundecene (DBU), 0.03 g of acetylene glycol surfactant SURFYNOL 465 (manufactured by Nissin Chemical Co., Ltd.) as a nonionic surfactant was dissolved, and further 1.00 g of the brown powder of the polyaniline conductive polymer obtained in the preparation example was dissolved to achieve a solid content concentration of 0.20 wt%. After stirring at room temperature for 2 hours, the mixture was filtered through a hydrophilic polyethylene filter as Comparative Example 6.

[0251] (Comparative Example 7)

[0252] In ultrapure water containing 0.067 g of triethylamine, 0.03 g of acetylene glycol surfactant SURFYNOL 465 (manufactured by Nissin Chemical Co., Ltd.) as a nonionic surfactant and 0.90 g of polyvinylpyrrolidone (manufactured by Nacalai Corporation) as a water-soluble polymer were dissolved, and 1.00 g of the brown powder of the polyaniline conductive polymer obtained in the preparation example was further dissolved to achieve a solid content concentration of 0.200 wt%. After stirring at room temperature for 2 hours, the mixture was filtered through a hydrophilic polyethylene filter as Comparative Example 7.

[0253] (Comparative Example 8)

[0254] In ultrapure water containing 0.17 g of tetra-n-butylammonium hydroxide, 0.03 g of acetylene glycol surfactant SURFYNOL 465 (manufactured by Nissin Chemical Co., Ltd.) as a nonionic surfactant and 0.90 g of polyvinylpyrrolidone (manufactured by Nacalai Corporation) as a water-soluble polymer were dissolved, and 1.00 g of the brown powder of the polyaniline conductive polymer obtained in the preparation example was further dissolved to achieve a solid content concentration of 0.200 wt%. After stirring at room temperature for 2 hours, the mixture was filtered through a hydrophilic polyethylene filter as Comparative Example 8.

[0255] (Comparative Example 9)

[0256] In ultrapure water containing 0.10 g of diazabicycloundecene (DBU), 0.03 g of acetylene glycol surfactant SURFYNOL 465 (manufactured by Nissin Chemical Co., Ltd.) as a nonionic surfactant and 0.90 g of polyvinylpyrrolidone (manufactured by Nacalai Corporation) as a water-soluble polymer were dissolved, and 1.00 g of the brown powder of the polyaniline conductive polymer obtained in the preparation example was further dissolved to achieve a solid content concentration of 0.200 wt%. After stirring at room temperature for 2 hours, the mixture was filtered through a hydrophilically treated polyethylene filter as Comparative Example 9.

[0257] (Evaluation of corrosion resist)

[0258] In the evaluation of antistatic films for electron beam-based offset printing (electron beam resist), Shin-Etsu Chemical Co., Ltd.'s positive chemical amplification electron beam resist (RP-1) was used as the simultaneously used positive chemical amplification electron beam resist. Furthermore, Shin-Etsu Chemical Co., Ltd.'s negative chemical amplification electron beam resist (RP-2) was used.

[0259] [Positive resist composition (R-1)]

[0260] A positive resist composition was prepared by dissolving polymer (RP-1) (100 parts by mass), acid-generating agent P-1 (8 parts by mass), acid diffusion control agent Q-1 (4 parts by mass), and surfactant in an organic solvent and filtering the resulting solutions through a 0.02 μm UPE filter.

[0261] [Negative type corrosion resist composition (R-2)]

[0262] A negative resist composition was prepared by dissolving polymer (RP-2) (100 parts by mass), acid-generating agent P-1 (5 parts by mass), fluorinated polymer D1 (3 parts by mass), diffusion control agent Q-1 (7 parts by mass), and surfactant in an organic solvent and filtering the resulting solutions through a 0.02 μm UPE filter.

[0263] In addition, PF-636 (manufactured by OMNOVA SOLUTIONS INC.) is added as a surfactant in each resist composition, and a mixed solvent of 1,204 parts by weight of propylene glycol monomethyl ether acetate (PGMEA), 1,204 parts by weight of ethyl lactate (EL) and 1,606 parts by weight of propylene glycol monomethyl ether (PGME) is used as an organic solvent.

[0264] [Chemical Formula 8]

[0265] Polymer (RP-1)

[0266]

[0267] [Chemical Formula 9]

[0268] Polymer (RP-2)

[0269]

[0270] [Chemical Formula 10]

[0271]

[0272] [Chemical Formula 11]

[0273]

[0274] [Chemical Formula 12]

[0275] Polymer D1

[0276] (a=0.80, b=0.20, Mw=6,000)

[0277]

[0278] (Electron beam resist and conductive polymer composition deposited on silicon wafer)

[0279] (R-1) and (R-2) were formed by spin-coating a 6-inch (150 mm) diameter silicon wafer using a CLEAN TRACK MARK VIII coater (manufactured by Tokyo Electron Limited). The films were then baked at 110°C for 240 seconds using a precision thermostat to remove the solvent. 2.0 mL of the conductive polymer compositions of Examples 1-39 and Comparative Examples 1-9 were then dropped onto the top layer, and the mixture was spin-coated onto the entire resist film using a spin coater. The spin-coating conditions were adjusted to achieve a film thickness of 80 ± 5 nm. The films were then baked at 90°C for 5 minutes using a precision thermostat to remove the solvent, thus obtaining an antistatic film. The resist film thickness and antistatic film thickness were determined using a VASE variable incident angle ellipsometry (manufactured by JAWOOLLAM JAPAN).

[0280] (Film-forming properties of conductive compositions)

[0281] In the film-forming process of the electron beam resist and the conductive polymer composition described above, cases where a uniform film of the conductive polymer composition is formed on the electron beam resist are marked as ○, and cases where defects or partial scratches from particles are generated on the film even though the refractive index can be measured are marked as ×. Evaluation is based on this standard. The evaluation results are shown in Table 2.

[0282] (Water washability)

[0283] The formed conductive polymer membrane was rinsed with ion-exchanged water from the wash bottle. The condition where the antistatic membrane peeled off uniformly within 10 seconds was marked with ◎, and the condition where the antistatic membrane peeled off uniformly between 10 and 20 seconds was marked with ○. Evaluation was based on this standard. The results are shown in Table 2.

[0284] (pH measurement)

[0285] The pH of the conductive polymer compositions of Examples 1-39 and Comparative Examples 1-9 was determined using a pH meter D-52 (manufactured by HORIBA, Ltd.). The results are shown in Table 2.

[0286] (Volume resistivity)

[0287] The volume resistivity (Ω·cm) of the conductive polymer films obtained by the above film formation method based on Examples 1-39 and Comparative Examples 1-9 was measured using a Loresta-GP MCP-T610 or a Hiresta-UP MCP-HT450 (both manufactured by Mitsubishi Chemical Corporation). The results are shown in Table 2.

[0288] [Table 2]

[0289]

[0290] (Evaluation of the rate of change in film thickness reduction)

[0291] When using a positive resist, the developed film exhibits the effect of acid diffusion from the conductive polymer film to the resist film, or the diffusion of additives to the resist film. Hereinafter, conductive polymer compositions from Examples 1-39 and Comparative Examples 1-9 were deposited on a positive resist (R-1), and after electron beam lithography, these conductive polymer compositions were developed through a PEB pre-peeling process or a PEB post-peeling process to obtain resist patterns. The rate of decrease in film thickness of the resist film was then measured.

[0292] PEB pre-peeling process evaluation

[0293] Using a Mark VIII (manufactured by Tokyo Electron Limited, CLEAN TRACK coating and developing machine), (R-1) as a positive chemical amplification resist was spin-coated onto a 6-inch silicon wafer, and pre-baked at 110°C for 240 seconds on a hot plate to create an 80 nm resist film <film thickness (T1)>. Similarly, using a Mark VIII, a conductive polymer composition was spin-coated onto the resulting resist-coated wafer, and baked at 90°C for 90 seconds on a hot plate to create a 20 nm conductive polymer film. Furthermore, exposure was performed using an electron beam exposure apparatus (manufactured by Hitachi High-Technologies Corporation, HL-800D, accelerating voltage 50keV), followed by rinsing with pure water for 15 seconds, peeling off the conductive polymer film, and baking at 90°C for 240 seconds (PEB: post-exposure bake). When developed with a 2.38% by mass tetramethylammonium hydroxide solution, a positive pattern <film thickness of the unexposed portion (T3)> was obtained.

[0294] Evaluation of PEB Post-Peeling Process

[0295] Using a Mark VIII (manufactured by Tokyo Electron Limited, CLEAN TRACK coating and developing machine), (R-1) as a positive chemical amplification resist was spin-coated onto a 6-inch silicon wafer, and pre-baked at 110°C for 240 seconds on a hot plate to create an 80 nm resist film <film thickness (T1)>. Similarly, using a Mark VIII, a conductive polymer composition was spin-coated onto the resulting resist-coated wafer, and baked at 90°C for 90 seconds on a hot plate to create a 20 nm conductive polymer film. Further, after exposure using an electron beam exposure apparatus (manufactured by Hitachi High-Technologies Corporation, HL-800D, accelerating voltage 50 keV), a post-exposure bake (PEB) was performed at 90°C for 240 seconds, followed by development with a 2.38% by mass tetramethylammonium hydroxide solution, resulting in a positive pattern <film thickness of unexposed areas (T3)>.

[0296] The same operation as the PEB post-peeling process is performed on the resist film without conductive polymer film. The optimal exposure amount after exposure and development and the resist film thickness (T2) of the unexposed part are determined. The film thickness reduction rate (film thickness change rate) in the PEB pre-peeling process and PEB post-peeling process of conductive polymer film are respectively calculated by the following formula.

[0297] Film thickness reduction rate (%) = {(T1-T3)-(T1-T2) / (T1-T2)}×100

[0298] The results are shown in Table 3.

[0299] [Table 3]

[0300]

[0301] (Electron beam lithography resolution evaluation)

[0302] The resist patterns obtained from resist films and conductive films deposited on a mask blank using the following process are evaluated.

[0303] PEB pre-peeling process evaluation

[0304] The resist composition prepared above was spin-coated onto a 152 mm square mask blank with a chromium oxynitride film on its outermost surface using an ACT-M (manufactured by Tokyo Electron Limited). The mask blank was pre-baked at 110°C for 600 seconds on a hot plate to produce an 80 nm resist film. The film thickness of the obtained resist film was measured using an optical measuring instrument, Nanospec (manufactured by Nano Matrix Co., Ltd.). Measurements were taken at 81 points in the plane of the substrate blank, excluding the outer edge portion from the outer perimeter of the blank to the inner 10 mm side, and the average film thickness and film thickness range were calculated. The conductive polymer compositions of Examples 1-39 and Comparative Examples 1-9 were then spin-coated onto the resulting mask blank with the resist film, and baked at 90°C for 90 seconds on a hot plate to produce a 20 nm conductive polymer film. Next, exposure was performed using an electron beam exposure apparatus (EBM-5000plus manufactured by NuFlare Technology, Inc., with an accelerating voltage of 50kV). After a 20-second water-based wash stripping, PEB was applied at 110°C for 600 seconds, followed by development with 2.38% by mass TMAH solution to obtain patterns of positive resist (R-1) and negative resist (R-2).

[0305] The obtained resist pattern was evaluated as follows. The patterned mask blank was observed from above using a SEM (scanning electron microscope). The optimal exposure (sensitivity) (μC / cm) was set to an exposure of 1:1 linewidth spacing (LS) at a resolution of 200 nm. 2 The minimum size in the exposure of a 200nm LS at a 1:1 resolution was set as the resolution (limiting resolution), and the edge roughness (LER) of the 200nm LS was measured using SEM. The shape of the pattern was visually determined to be rectangular. The results for the positive resist (R-1) are shown in Table 4, and the results for the negative resist are shown in Table 5.

[0306] [Table 4]

[0307]

[0308] [Table 5]

[0309]

[0310] Evaluation of PEB Post-Peeling Process

[0311] The resist composition prepared above was spin-coated onto a 152 mm square mask blank with a chromium oxynitride film on its outermost surface using an ACT-M (manufactured by Tokyo Electron Limited). The blank was pre-baked at 110°C for 600 seconds on a hot plate to produce an 80 nm resist film. The film thickness of the obtained resist film was measured using an optical measuring instrument, Nanospec (manufactured by Nano Matrix Co., Ltd.). Measurements were taken at 81 points in the plane of the blank substrate, excluding the outer edge portion from the outer perimeter of the blank to the inner 10 mm side, and the average film thickness and film thickness range were calculated. The conductive polymer compositions of Examples 1-39 and Comparative Examples 1-9 were then spin-coated onto the resulting wafers with resist films, and baked at 90°C for 90 seconds on a hot plate to produce 20 nm conductive polymer films. Next, exposure was performed using an electron beam lithography apparatus (EBM-5000plus manufactured by NuFlare Technology, Inc., with an accelerating voltage of 50kV), with PEB applied at 110°C for 600 seconds, followed by development with 2.38% by mass TMAH solution to obtain patterns of positive resist (R-1) and negative resist (R-2).

[0312] The obtained resist pattern was evaluated as follows. The patterned mask blank was observed from above using a SEM (scanning electron microscope). The optimal exposure (sensitivity) (μC / cm) was set to an exposure of 1:1 linewidth spacing (LS) at a resolution of 200 nm. 2 The minimum size in the exposure of a 200nm LS at a 1:1 resolution was set as the resolution (limiting resolution), and the edge roughness (LER) of the 200nm LS was measured using SEM. The shape of the pattern was visually determined to be rectangular. The results for the positive resist (R-1) are shown in Table 6, and the results for the negative resist are shown in Table 7.

[0313] [Table 6]

[0314]

[0315] [Table 7]

[0316]

[0317] In Table 2, Examples 1-39 and Comparative Examples 1-9 all exhibited good spin-coating properties on the electron beam resist and formed uniform films. On the other hand, regarding water-washable peelability, Examples 27-39 and Comparative Examples 7-9, which contained polyvinylpyrrolidone (manufactured by Nacalai Corporation) as a water-soluble (D) polymer, showed the highest peelability. Although there were no significant differences between the Examples and Comparative Examples, the effectiveness of adding the water-soluble (D) polymer was confirmed for water-washable peelability.

[0318] In Examples 1-39, since a carboxylate as component (B) was added to the polyaniline polymer compound of component (A) to form a conductive polymer composition, component (B) undergoes ion exchange with the sulfonic acid terminus of component (A), resulting in a weakly acidic region with a pH of 4.5-5.3. In contrast, in Comparative Examples 1-9, since component (B) is a strongly alkaline substance, it neutralizes the sulfonic acid terminus of component (A), resulting in a region with a higher pH and approaching neutrality. Since this result is an evaluation of the solution properties before film formation, the effectiveness of the examples relative to the comparative examples is not yet clear. However, these conductive polymer compositions, when coated and film-formed on an electron beam resist and subjected to electron beam lithography and PEB processes, produce significant differences in offset printing.

[0319] Furthermore, in Examples 1-39, the volume resistivity (Ω·cm) of the conductive polymer film showed a relatively low value, indicating that the antistatic function could be fully utilized. However, in Comparative Examples 1-9, because a strongly alkaline substance was added to replace the carboxylate of component (B), a side reaction occurred on the resist film, resulting in a larger volume resistivity (Ω·cm) of the conductive polymer film, which could not fully perform the antistatic function.

[0320] In Table 3, the conductive polymer compositions of Examples 1-39 and Comparative Examples 1-9 were formed into films on a positive electron beam resist (R-1) and subjected to a PEB pre-stripping process followed by PEB pattern development, or the resist pattern was developed after PEB without a PEB pre-stripping process and then lithographic printing. The film thickness reduction rate was compared based on the lithographic printing results. In Examples 1-39, regardless of the type of resist or the resist patterning process, the film thickness reduction rate was as low as 15-25%. In contrast, the film thickness reduction rate of Comparative Examples 1-9 was very high, at 30-50%. The (B) component of Examples 1-39 had a small effect on the chemical reactions of the constituent elements of the electron beam resist. In contrast, the strongly alkaline substances in Comparative Examples 1-9 not only neutralized the acid but also performed nucleophilic attacks on the constituent elements of the electron beam resist, thus altering the function of the electron beam resist and increasing the film thickness reduction rate after development.

[0321] In Tables 4-7, the conductive polymer compositions of Examples 1-39 and Comparative Examples 1-9 were formed into films on positive electron beam resist (R-1) and negative electron beam resist (R-2), and then subjected to a PEB pre-peeling process and PEB for resist pattern development, or the resist pattern was developed after PEB without a PEB pre-peeling process and then lithographic printing was performed. The optimal exposure (μC / cm) was compared based on the lithographic printing results. 2 Regarding the photosensitivity, resolution (limited resolution), edge roughness (LER), and pattern shape in Examples 1-39, regardless of the type of resist used or the resist patterning process, the changes were minimal. The limited resolution and edge roughness (LER) were also the same as those of offset printing with only resist and no conductive polymer composition. The pattern shape after development also maintained a rectangular shape, without any damage to the resist performance. On the other hand, in Comparative Examples 1-9, as described above, the chemical reactions of the constituent elements of the electron beam resist had a significant impact. The strongly alkaline substances not only neutralized the acid in the conductive polymer composition but also carried out nucleophilic attacks on the constituent elements of the electron beam resist after film formation, thus affecting the photosensitivity and offset printing performance of the electron beam resist, resulting in a deterioration in resolution, edge roughness (LER), and pattern shape.

[0322] (Electron beam offset printing evaluation and PCD (Post Coating Delay) evaluation)

[0323] Next, the time-dependent changes caused by the influence of the conductive polymer film on the resist film before electron beam irradiation were measured. The resist film and the conductive polymer film, coated using the method described below, were placed in an electron beam lithography apparatus for 7, 14, and 30 days immediately after film formation. Resist patterns were then obtained through a PEB pre-peeling process or a PEB post-peeling process for the conductive polymer film, as described below. The fluctuation in pattern linewidth at the same photosensitivity was calculated for both the newly formed resist and the conductive polymer film.

[0324] PEB pre-peeling process evaluation

[0325] Using a Mark VIII (manufactured by Tokyo Electron Limited, CLEAN TRACK coating and developing machine), a positive chemically amplified resist (R-1) was spin-coated onto a 6-inch silicon wafer and pre-baked at 110°C for 240 seconds on a hot plate to create a resist film with a thickness of 80 nm. Similarly, using a Mark VIII, a conductive polymer composition was spin-coated onto the resulting wafer with the resist film and baked at 90°C for 90 seconds on a hot plate to create a conductive polymer film. For wafers coated with both the resist film and the conductive polymer film, resist patterns were obtained immediately after coating, at 7 days, 14 days, and 30 days later, using the following methods. First, the freshly coated wafer was exposed using an electron beam exposure apparatus (Hitachi High-Technologies Corporation, HL-800D, accelerating voltage 50keV). Then, it was rinsed with pure water for 20 seconds to strip the conductive polymer film. It was then baked at 110°C for 240 seconds (PEB: post-exposure bake) and developed with a 2.38% by mass tetramethylammonium hydroxide solution. The patterned wafer was observed from above using a scanning electron microscope (SEM). The optimal exposure (sensitivity) (μC / cm²) was set at a 1:1 resolution linewidth spacing of 400 nm. 2 The minimum size in the optimal exposure is set as the resolution. Furthermore, resist patterns were obtained in the same manner for wafers after 7, 14, and 30 days following coating. For wafers immediately after coating, the exposure (optimal exposure (sensitivity)) at a 1:1 resolution of 200 nm linewidth intervals was measured. 2 The fluctuation of the pattern linewidth in the diagram is shown in Table 8.

[0326] Evaluation of PEB Post-Peeling Process

[0327] Using the same method as the PEB pre-peeling process, wafers coated with both a resist film and a conductive polymer film were fabricated. For wafers that had been coated for 7, 14, and 30 days, after electron beam exposure, instead of rinsing with pure water for 20 seconds to peel off the conductive polymer film, they were baked at 110°C for 240 seconds (PEB: postexposure bake), and developed with a 2.38% by mass tetramethylammonium hydroxide solution to obtain the resist pattern. For the wafers immediately after coating, the exposure amount (optimal exposure amount (sensitivity)) at a 1:1 resolution of 200 nm linewidth intervals was measured (μC / cm²). 2 The fluctuation of the pattern linewidth in the diagram is shown in Table 9.

[0328] For the negative resist (R-2), the PEB pre-stripping and post-stripping processes were evaluated in the same manner as for the positive resist (R-1). The results are shown in Tables 10 and 11.

[0329] [Table 8]

[0330] Positive resist (R-1) PEB pre-stripping process PcD

[0331]

[0332] [Table 9]

[0333] Positive resist (R-1) PEB post-stripping process PCD

[0334]

[0335] [Table 10]

[0336] Negative resist (R-2) PEB pre-stripping process PcD

[0337]

[0338] [Table 11]

[0339] Post-PEP stripping process PCD with negative resist (R-2) PEB

[0340]

[0341] As shown in Tables 8-11, in the PCD (Post Coating Delay) evaluation, the compositions of Examples 1-39, which effectively suppressed the influence of acid from the conductive polymer film to the electron beam resist layer, maintained good storage stability of the resist film even after it was formed into a conductive film on top of the resist. This implies that by suppressing the diffusion of acid from the conductive polymer film in the resist film and its superposition of the conductive polymer film (antistatic film) before electron beam lithography, good lithographic printing results can be obtained in the processes of drawing, peeling off the conductive polymer film (antistatic film), and pattern development. On the other hand, for the compositions of Comparative Examples 1-9, the addition of strong alkaline substances to the compositions resulted in a high efficiency in neutralizing acidity, exhibiting a near-neutral solution nature. However, after film formation, these strong alkaline substances caused side reactions such as nucleophilic attacks on the constituent elements of the electron beam resist and a decrease in the amplification efficiency of acid production after painting. Excessive acid diffusion or localized excessive acid quenching occurred within the resist film, adversely affecting lithographic printing. The longer the film formation time on top of the resist layer, the greater the impact, even in the case of a PEB pre-peeling process.

[0342] As described above, the conductive polymer composition of the present invention can form an antistatic film with excellent antistatic properties when drawn on an electron beam resist, and minimizes the influence of acid on the resist. Compositions with such conductivity and the ability to prevent the effects of acid are also effective as constituent films for organic thin-film devices. As long as the influence of acid on adjacent layers can be suppressed, and the composition functions as a conductive or carrier migration medium within the laminated structure, it can be suitably used as a device constituent material.

[0343] Furthermore, the present invention is not limited to the above-described embodiments. The above embodiments are illustrative examples, and any technical solution having a substantially identical structure and achieving the same effect as the technical concept described in the claims of the present invention is included within the technical scope of the present invention.

Claims

1. A conductive polymer composition, characterized in that, It comprises: (A) a polyaniline conductive polymer having at least one repeating unit represented by the following general formula (1), and (B) a carboxylate represented by the following general formula (2). The conductive polymer composition further contains (D) a water-soluble polymer. The content of component (D) is 30 to 150 parts by mass relative to 100 parts by mass of component (A). In the formula, R1 to R4 each independently represent a hydrogen atom, an acidic group, a hydroxyl group, a nitro group, a halogen atom, a straight-chain or branched alkyl group with 1 to 24 carbon atoms, a straight-chain, branched, or cyclic hydrocarbon group with 1 to 24 carbon atoms containing heteroatoms, or a straight-chain, branched, or cyclic hydrocarbon group with 1 to 24 carbon atoms partially substituted by a halogen atom. In the formula, X + The following represents lithium ions, sodium ions, potassium ions, or nitrogen compounds represented by the general formula (3) below. L represents a single bond, or a straight-chain, branched, or cyclic saturated or unsaturated hydrocarbon chain with 1 to 8 carbon atoms that can be intercalated with heteroatoms. When L is a single bond, n = 0; when L is not a single bond, n = 1. R5 and R6 independently represent hydrogen atoms, heteroatoms, and -COO atoms, respectively. - X + The radical, hydroxyl group, a straight-chain, branched, or cyclic monovalent hydrocarbon group with 1 to 20 carbon atoms that can be inserted with heteroatoms, or a terminal group with -COO - X + The radical is a straight-chain, branched, or cyclic saturated or unsaturated hydrocarbon group with 1 to 8 carbon atoms, where R7 represents a hydrogen atom, a hydroxyl group, or -COO. - X + base, In the formula, R 101 R 102 R 103 R 104 These groups represent hydrogen atoms, linear, branched, or cyclic alkyl, alkenyl, oxoalkyl, or oxoalkenyl groups with 1 to 12 carbon atoms, aryl groups with 6 to 20 carbon atoms, or aralkyl or aryloxoalkyl groups with 7 to 12 carbon atoms, wherein some or all of the hydrogen atoms in these groups may be replaced by alkoxy groups, R 101 With R 102 R 101 With R 102 and R 104 A ring can be formed; when a ring is formed, R 101 With R 102 and R 101 With R 102 and R 104 It represents an alkylene group having 3 to 10 carbon atoms, or an aromatic heterocycle having a nitrogen atom in the formula in the ring.

2. The conductive polymer composition according to claim 1, characterized in that, The acidic group is a sulfonyl group.

3. The conductive polymer composition according to claim 1, characterized in that, The content of component (B) is 1 to 70 parts by mass relative to 100 parts by mass of component (A).

4. The conductive polymer composition according to claim 2, characterized in that, The content of component (B) is 1 to 70 parts by mass relative to 100 parts by mass of component (A).

5. The conductive polymer composition according to claim 1, characterized in that, The conductive polymer composition further contains (C) a nonionic surfactant.

6. The conductive polymer composition according to claim 2, characterized in that, The conductive polymer composition further contains (C) a nonionic surfactant.

7. The conductive polymer composition according to claim 3, characterized in that, The conductive polymer composition further contains (C) a nonionic surfactant.

8. The conductive polymer composition according to claim 4, characterized in that, The conductive polymer composition further contains (C) a nonionic surfactant.

9. The conductive polymer composition according to claim 5, characterized in that, The content of component (C) is 0.1 to 10 parts by mass relative to 100 parts by mass of component (A).

10. The conductive polymer composition according to claim 6, characterized in that, The content of component (C) is 0.1 to 10 parts by mass relative to 100 parts by mass of component (A).

11. The conductive polymer composition according to claim 7, characterized in that, The content of component (C) is 0.1 to 10 parts by mass relative to 100 parts by mass of component (A).

12. The conductive polymer composition according to claim 8, characterized in that, The content of component (C) is 0.1 to 10 parts by mass relative to 100 parts by mass of component (A).

13. A covering, characterized in that, It is formed by forming a film on the workpiece using any one of the conductive polymer compositions according to claims 1 to 12.

14. The covering according to claim 13, characterized in that, The workpiece being processed is a substrate with a chemically amplified resist film.

15. The covering according to claim 14, characterized in that, The workpiece is a substrate used to obtain a resist pattern by patterning an electron beam.

16. The covering according to claim 14, characterized in that, The workpiece being processed has a temperature of 20 μC / cm. 2 The above-mentioned photosensitivity is achieved by using a chemically amplified electron beam resist film on a substrate.

17. The covering according to claim 15, characterized in that, The workpiece being processed has a temperature of 20 μC / cm. 2 The above-mentioned photosensitivity is achieved by using a chemically amplified electron beam resist film on a substrate.

18. A method for forming a pattern, characterized in that, It includes: a step of forming an antistatic film on a substrate having a chemically amplified resist film using the conductive polymer composition of any one of claims 1 to 12; a step of patterning by electron beam irradiation; and a step of developing the resist pattern using H2O or an alkaline developer.

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