JP2010113142A - Positive photosensitive composition and method for forming electrically conductive pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive photosensitive composition which, when used as a resist material, can be decomposed and removed at a low temperature and ensures a very small residual amount of undecomposed components, and a method for forming an electrically conductive pattern using the positive photosensitive composition. <P>SOLUTION: The positive photosensitive composition contains a resin (A) having a noncyclic acetal structural unit of a specific structure and a photoacid generator (B), wherein the ratio of the number of carbon atoms to the number of oxygen atoms in the resin (A) having the noncyclic acetal structural unit of a specific structure is 2.3-6.0. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a positive photosensitive composition that can be decomposed and removed at a low temperature when used as a resist material and has a very small residual amount of undecomposed components. The present invention also relates to a method for forming a conductive pattern using the positive photosensitive composition.

In the manufacturing process of a substrate for an electronic device such as a silicon wafer for semiconductor, generally, a photoresist composition is applied on a semiconductor wafer such as a silicon substrate to form a resist film, and exposed through a mask having a predetermined pattern. A photolithography process is used in which a mask pattern is transferred to a resist film to form a resist pattern by performing development. In the photolithography process, a process for removing organic substances adhering to the surface of the substrate, such as removal of resist and general organic substances such as resist residues, is indispensable. In particular, the removal of the resist is an extremely important step in the entire production of the electronic device substrate.

When a circuit is formed on a semiconductor substrate such as a silicon substrate or a gallium arsenide substrate, when a plurality of colored pixels having different hues are formed in a pattern on a liquid crystal substrate, or a circuit pattern to be formed on a semiconductor substrate or the like When manufacturing a mask substrate having a corresponding mask pattern, a photolithography process is essential. For example, when forming a circuit on a silicon substrate, a resist is coated on a silicon wafer, a resist pattern is formed by a normal photolithography process, and a sputtering method, a plating method, or the like is used for the formed resist pattern. After the conductive film is formed, the resist that is no longer needed is removed to form a conductive pattern, and in order to form the next conductive pattern, the resist is applied again to form a resist pattern—the conductive film. The cycle of forming and removing the resist is repeated.

In the step of removing the resist that is no longer needed, for example, a method of removing the resist using a solvent, chemicals, ozone, or the like is used. In Patent Document 1, the resist pattern is stripped using an alkaline solution. A method is disclosed.
However, when solvents, chemicals, ozone water, etc. are used to remove the resist, a large amount of waste liquid is generated, and the waste liquid cannot be discarded as it is. There was a profit.
Japanese Patent Laid-Open No. 06-258832

An object of the present invention is to provide a positive photosensitive composition that can be decomposed and removed at a low temperature when used as a resist material and has a very small amount of undecomposed components. Another object of the present invention is to provide a method for forming a conductive pattern using the positive photosensitive composition.

The present invention is a positive photosensitive composition comprising a resin (A) having an acyclic acetal structural unit and a photoacid generator (B), the resin having the acyclic acetal structural unit (A). Is a resin (A1) having a structural unit represented by the following general formula (1), a resin (A2) having a structural unit represented by the following general formulas (3) and (4), or the following general formula ( The number of carbon atoms relative to the number of oxygen atoms in the resin (A3) having the structural units represented by 1), (2), (3) and (4) and having the acyclic acetal structural unit Is a positive photosensitive composition having a ratio of 2.3 to 6.0.

In general formulas (1) to (4), R ¹ , R ² , and R ³ represent a divalent organic group, a to d represent an integer of 1 or more, and c / d is 0.8. ~ 1.2.
The present invention is described in detail below.

In recent years, a method for removing a resist by thermally decomposing the resist at a high temperature has been developed as disclosed in Japanese Patent Application Laid-Open No. 2007-171311 in place of the resist removal step by etching or the like. Such a method is an excellent method from the viewpoint of environmental protection.
However, when a conventionally used sinterable composition is used as a resist material, there is a problem that undecomposed components remain after the resist removal step due to low thermal decomposability.
As a method for preventing the remaining of undecomposed components, it is conceivable to raise the heating temperature in the resist removal process. However, if thermal decomposition is performed at a high temperature of 350 ° C. or higher, a substrate such as a silicon wafer is damaged by heat. There was a problem.
Therefore, the present inventors have found that by using a positive photosensitive composition containing a resin having a specific structure and a photoacid generator as a resist material, it can be decomposed and removed at a low temperature. It came to complete.

The positive photosensitive composition of the present invention contains a resin (A) having an acyclic acetal structural unit.
The resin (A) having the acyclic acetal structural unit includes the resin (A1) having the structural unit represented by the general formula (1) and the structural units represented by the general formulas (3) and (4). Resin (A2) or a resin (A3) having a structural unit represented by the general formulas (1), (2), (3) and (4).
By containing the resin (A) having the acyclic acetal structural unit, the positive photosensitive composition of the present invention can be decomposed and removed at a low temperature when used as a resist material. The residual amount of undecomposed components after the removing step can be greatly reduced.

In the general formulas (1) to (4), a to d represent an integer of 1 or more, and c / d is 0.8 to 1.2. When the c / d is out of the above range, the number average molecular weight of the resin (A) having the acyclic acetal structural unit may be remarkably reduced.

In the above general formulas (1) to (4), R ¹ , R ² , and R ³ are divalent organic groups. R ¹ , R ² , and R ³ are preferably at least one selected from the group consisting of structural units represented by the following general formulas (5) to (14). By having the structural unit described above, it is possible to easily control the low-temperature decomposability and rheological properties of the resulting positive photosensitive composition.
Further, R ¹ , R ² , and R ³ represent hydrogen in the structural units represented by the following general formulas (5) to (14) as alkyl groups, hydroxyl groups, carboxyl groups, ester groups, alkoxy groups, amino groups, It may be substituted with an amide group or the like.

e represents an integer of 3 or more, and f and g represent an integer of 1 or more.

In the structural unit represented by the general formula (5), e represents an integer of 3 or more. When the e is less than 3, the polarity of the resin (A) having the acyclic acetal structural unit is increased, and the time required for thermal decomposition of the obtained positive photosensitive composition may be increased. The preferable upper limit of the above e is 12. When the above e exceeds 12, the content of acetal groups in the resin is remarkably reduced, and the time required for thermal decomposition of the resulting positive photosensitive composition may be prolonged. The preferable lower limit of e is 4.

In the structural unit represented by the general formula (7), f is an integer of 1 or more, and a preferable lower limit of f is 10 and a preferable upper limit is 500. When f is less than 10, the flexibility of the resin (A) having the acyclic acetal structural unit may not be sufficiently obtained. When the above f exceeds 500, the proportion of acetal units in the resin decreases, and the resulting positive photosensitive composition may not be sufficiently heat-decomposable at low temperatures.

In the structural unit represented by the general formula (8), g is an integer of 1 or more, and the preferable lower limit of g is 5 and the preferable upper limit is 500. When the g is less than 5, the cohesiveness of the resin (A) having the acyclic acetal structural unit may not be sufficiently obtained. When g exceeds 500, the ratio of the acetal unit in the resin (A) having the acyclic acetal structural unit decreases, and the resulting positive photosensitive composition has sufficient thermal decomposability at low temperatures. It may not be possible.

The lower limit of the ratio of the number of carbon atoms to the number of oxygen atoms (number of carbon atoms / number of oxygen atoms) in the resin (A) having the acyclic acetal structural unit is 2.3, and the upper limit is 6.0. When the ratio of the number of carbon atoms to the number of oxygen atoms is less than 2.3, the polarity of the resin (A) having the acyclic acetal structural unit is increased and water in the air is easily absorbed. It is difficult to apply the resulting positive photosensitive composition because the viscosity of the photosensitive composition becomes insufficient or the time required for thermal decomposition of the resulting positive photosensitive composition becomes longer. become. When the ratio of the number of carbon atoms to the number of oxygen atoms exceeds 6.0, the acetal group content ratio in the resin (A) having the acyclic acetal structural unit is decreased, and the heat of the positive photosensitive composition obtained is increased. It takes longer time to decompose. The preferable lower limit of the ratio of the number of carbon atoms to the number of oxygen atoms is 2.5, and the preferable upper limit is 5.0.

The number average molecular weight of the resin (A) having the acyclic acetal structural unit is not particularly limited, but a preferable lower limit is 1000 and a preferable upper limit is 1,000,000. When the number average molecular weight of the resin (A) having an acyclic acetal structural unit is less than 1000, the resulting positive photosensitive composition has insufficient viscosity, and the resulting positive photosensitive composition is applied. Can be difficult. When the number average molecular weight of the resin (A) having the acyclic acetal structural unit exceeds 1,000,000, the viscosity of the resulting positive photosensitive composition is remarkably increased, and the resulting positive photosensitive composition is applied. Can be difficult.
In addition, in this specification, the said number average molecular weight is measured using a gel permeation chromatography (GPC), and is calculated | required by polystyrene conversion.

The resin (A1) having the structural unit represented by the general formula (1) is, for example, a polymerizable composition containing a compound (a1) having one vinyloxy group and one hydroxyl group in one molecule. Can be obtained by the method of polyaddition.

The compound (a1) having one vinyloxy group and one hydroxyl group in one molecule is not particularly limited, and examples thereof include 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, 9-hydroxynonyl vinyl ether, diethylene glycol mono Examples include vinyl ether, triethylene glycol monovinyl ether, tetraethylene glycol monovinyl ether, 4-hydroxycyclohexyl vinyl ether, cyclohexane-1,4-dimethanol monovinyl ether, and the like.

The resin (A2) having the structural unit represented by the general formulas (3) and (4) includes, for example, a compound (a2) having two vinyloxy groups in one molecule and two resins in one molecule. It can be obtained by a method of polyadding a polymerizable composition containing a compound (a3) having a hydroxyl group.

In this case, the preferable lower limit of the molar ratio of vinyloxy group to hydroxyl group in the polymerizable composition containing the compound (a2) and the compound (a3) is 0.8, and the preferable upper limit is 1.2. When the molar ratio is out of the above range, the stoichiometric ratio between the vinyloxy group and the hydroxyl group may be significantly shifted, and the number average molecular weight of the resin (A) having the acyclic acetal structural unit may be significantly reduced.

The compound (a2) having two vinyloxy groups in one molecule is not particularly limited, and examples thereof include divinyl ether, 1,4-butanediol divinyl ether, 1,9-nonanediol divinyl ether, 1,4-cyclohexane. Examples include diol divinyl ether, 1,4-cyclohexanedimethanol divinyl ether, ethylene glycol divinyl ether, diethylene glycol divinyl ether, and triethylene glycol divinyl ether.

The compound (a3) having two hydroxyl groups in one molecule is not particularly limited. For example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyethylene glycol-polypropylene glycol copolymer, polyethylene glycol-polytetramethylene glycol copolymer, polypropylene glycol- A polytetramethylene glycol copolymer, polyester diol, etc. are mentioned.

The resin (A3) having the structural units represented by the general formulas (1), (2), (3) and (4) has, for example, one vinyloxy group and one hydroxyl group in one molecule. A polymerizable composition containing a compound having a compound (a1), a compound (a2) having two vinyloxy groups in one molecule, and a compound (a3) having two hydroxyl groups in one molecule Obtained by the method.

In this case, the preferable lower limit of the molar ratio of the vinyloxy group to the hydroxyl group in the polymerizable composition containing the compound (a1), the compound (a2) and the compound (a3) is 0.8, and the preferable upper limit is 1.2. It is. When the molar ratio is out of the above range, the stoichiometric ratio between the vinyloxy group and the hydroxyl group may be significantly shifted, and the number average molecular weight of the resin (A) having the acyclic acetal structural unit may be significantly reduced.

A polymerizable composition containing the above (a1), a polymerizable composition containing the compound (a2) and the compound (a3), and the compound (a1), the compound (a2) and the compound (a3). The polymerizable composition to be contained preferably further contains a resin (a4) having a hydroxyl group in one molecule and having a number average molecular weight of 1,000 to 500,000. By containing the resin (a4), the resin (A) having the acyclic acetal structural unit is grafted or blocked to the resin (a4), whereby a comb-shaped resin or a block copolymer is obtained. Therefore, it becomes easy to control the rheological properties of the positive photosensitive composition obtained.

The resin (a4) is not particularly limited, and examples thereof include polyvinyl acetal resins, cellulose derivatives, hydroxyl group-containing (meth) acrylate copolymers, polyether polyols, polyester polyols, and polycarbonate polyols. Of these, polyvinyl acetal resins, cellulose derivatives, and hydroxyl group-containing (meth) acrylate copolymers are preferred.

The polyvinyl acetal resin is not particularly limited, and examples thereof include polyvinyl formal, polyvinyl propanal, and polyvinyl butyral.
The cellulose derivative is not particularly limited, and examples thereof include ethyl cellulose and nitrocellulose.
The hydroxyl group-containing (meth) acrylate copolymer is not particularly limited. For example, 2-hydroxyethyl (meth) acrylate copolymer, 4-hydroxybutyl (meth) acrylate copolymer, 1,4-cyclohexanedimethanol mono (Meth) acrylate copolymer, polyethylene glycol mono (meth) acrylate copolymer, polypropylene glycol mono (meth) acrylate copolymer, polytetramethylene glycol mono (meth) acrylate copolymer, and the like.

A polymerizable composition containing the above (a1), a polymerizable composition containing the compound (a2) and the compound (a3), and the compound (a1), the compound (a2) and the compound (a3). The polymerizable composition to be contained preferably further contains a compound (a5) having 3 or more hydroxyl groups in one molecule and having a number average molecular weight of 80 or more and less than 1000. By containing the compound (a5) in the polymerization reaction solution, the resin (A) having the acyclic acetal structural unit can be made into a radial shape, and the resulting positive photosensitive composition can be dried at the time of solvent drying. The thickening behavior can be controlled.

The compound (a5) having 3 or more hydroxyl groups in one molecule and having a number average molecular weight of 80 or more and less than 1000 is not particularly limited, and examples thereof include glycerin and polyglycerin.

A polymerizable composition containing the above (a1), a polymerizable composition containing the compound (a2) and the compound (a3), and the compound (a1), the compound (a2) and the compound (a3). The polymerizable composition to be contained may contain a polymerization solvent for adjusting the viscosity of the reaction solution and stabilizing the polymerization temperature.
The above-mentioned polymerization solvent is a solvent that can make each of the above-described components into a uniform polymerization reaction system, and a solvent that does not have a functional group containing active hydrogen such as a hydroxyl group, a phenolic hydroxyl group, a carboxyl group, and an amino group. Is preferred.
The polymerization solvent is not particularly limited, and examples thereof include aromatic solvents, aliphatic solvents, ester solvents, ether solvents, ketone solvents, and terpene solvents.

The aromatic solvent is not particularly limited, and examples thereof include benzene, toluene, xylene, mesitylene, ethylbenzene, amylbenzene, and anisole.
The aliphatic solvent is not particularly limited, and examples thereof include pentane, isopentane, hexane, heptane, cyclohexane, methylcyclohexane, dimethylcyclohexane, and petroleum ether.
The ester solvent is not particularly limited, and examples thereof include ethyl formate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, and butyl acetate.
The ether solvent is not particularly limited, for example, diethyl ether, methyl tert-butyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, triethylene glycol dibutyl ether, Examples include propylene glycol dimethyl ether and butyl carbitol acetate.
The ketone solvent is not particularly limited, and examples thereof include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.
The terpene solvent is not particularly limited. For example, α-pinene, β-pinene, camphene, p-cymene, limonene, terpinolene, α-terpinene, γ-terpinene, isobornyl acetate, α-terpinyl acetate, Examples include camphor, pinan, menthane, and menten.

A polymerizable composition containing the above (a1), a polymerizable composition containing the compound (a2) and the compound (a3), and the compound (a1), the compound (a2) and the compound (a3). It is preferable that the polymerizable composition to contain contains a molecular weight modifier.
The molecular weight modifier is not particularly limited. For example, water, monovinyl ether not containing a hydroxyl group, methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, 2-ethylhexyl vinyl ether, octadecyl vinyl ether Cyclohexyl vinyl ether, 2-chloroethyl vinyl ether, and the like.

Moreover, monool can be used as said molecular weight regulator.
The monool is not particularly limited. For example, methanol, ethanol, propanol, isopropanol, butanol, sec-butanol, tert-butanol, hexanol, n-octanol, 2-ethylhexanol, cyclohexanol, benzyl alcohol, diethylene glycol monomethyl ether, Examples include polyethylene glycol monomethyl ether, polypropylene glycol monomethyl ether, polytetramethylene glycol monomethyl ether, diethylene glycol monobutyl ether, polyethylene glycol monobutyl ether, polypropylene glycol monobutyl ether, polytetramethylene glycol monobutyl ether.

A polymerizable composition containing the above (a1), a polymerizable composition containing the compound (a2) and the compound (a3), and the compound (a1), the compound (a2) and the compound (a3). The upper limit with the preferable water content of the polymeric composition to contain is 1000 ppm. If it exceeds 1000 ppm, the addition reaction with water increases, and the number average molecular weight of the resin (A) having the acyclic acetal structural unit may be significantly reduced.

The resin (A) having the acyclic acetal structural unit is a polymerizable composition containing the above (a1), a polymerizable composition containing the compound (a2) and the compound (a3), or the above compound ( Although it can be obtained by polyaddition of a polymerizable composition containing a1), compound (a2) and compound (a3), it is preferable to use an acid catalyst when performing the above polyaddition.
The acid catalyst is not particularly limited. For example, methanesulfonic acid, ethanesulfonic acid, trifluoromethanesulfonic acid, camphorsulfonic acid, p-toluenesulfonic acid, benzenesulfonic acid, naphthalenesulfonic acid, sulfonated polystyrene and its crosslinked resin, Examples include sulfuric acid, trifluoroacetic acid, trichloroacetic acid, tribromoacetic acid, methyl phosphoric acid, dimethyl phosphoric acid, ethyl phosphoric acid, diphenyl phosphate, phosphoric acid, and hydrogen iodide.

Although the reaction temperature at the time of manufacturing the resin (A) having the acyclic acetal structural unit may be appropriately adjusted, it is preferably -78 to 70 ° C. In this case, the pressure during the reaction is usually normal pressure, but may be increased or decreased.
Further, when the resin (A) having the acyclic acetal structural unit is produced, a dehydrating agent such as molecular sieves or silica gel having a low reactivity with a hydroxyl group or a silica gel or a water absorbing agent are appropriately used in order to keep the water content during polymerization low. It may be added.
After completion of the reaction, the polymerization solvent and residual monomers are removed under reduced pressure by a conventional method, and the obtained resin (A) having the acyclic acetal structural unit is taken out or reprecipitated using a solvent in which the resin is insoluble. By performing the treatment, the resin (A) having the acyclic acetal structural unit can be isolated.

The positive photosensitive composition of the present invention contains a photoacid generator (B).
The photoacid generator (B) is not particularly limited, but halogen-containing s-triazine derivatives, halogen-substituted paraffin hydrocarbons, halogen-substituted cycloparaffin hydrocarbons, halogen-containing benzene derivatives, halogen-containing sulfone compounds, halogen-containing isocyanurates Derivatives, sulfonium salts, iodonium salts, oxime sulfonates, sulfonate esters, disulfones, carbonylsulfonyldiazomethanes, bissulfonylmethanes, bissulfonyldiazomethanes, o-nitrobenzyl esters, sulfone hydrazides, and iminosulfonates It is preferable that it is at least one selected from the group consisting of a group.

The halogen-containing s-triazine derivative is not particularly limited, and examples thereof include tris (trichloromethyl) -s-triazine, tris (tribromomethyl) -s-triazine, tris (dibromomethyl) -s-triazine, 2,4- Bis (tribromomethyl) -6-p-methoxyphenyl-s-triazine and the like can be mentioned.
The halogen-substituted paraffinic hydrocarbon is not particularly limited, and examples thereof include 1,2,3,4-tetrabromobutane, 1,1,2,2-tetrabromoethane, carbon tetrabromide, iodoform and the like.
The halogen-substituted cycloparaffinic hydrocarbon is not particularly limited, and examples thereof include hexabromocyclohexane, hexachlorocyclohexane, hexabromocyclododecane and the like.
The halogen-containing benzene derivative is not particularly limited, and examples thereof include bis (trichloromethyl) benzene and bis (tribromomethyl) benzene.
The halogen-containing sulfone compound is not particularly limited, and examples thereof include tribromomethylphenyl sulfone, trichloromethylphenyl sulfone, 2,3-dibromosulfolane, and the like.
The halogen-containing isocyanurate derivative is not particularly limited, and examples thereof include tris (2,3-dibromopropyl) isocyanurate.
The sulfonium salt is not particularly limited. For example, triphenylsulfonium chloride, triphenylsulfonium methanesulfonate, triphenylsulfonium trifluoromethylsulfonate, triphenylsulfonium, p-toluenesulfonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexa Examples include fluoroarsenate, triphenylsulfonium hexafluorophosphonate, 4,4 ′-[di (β-hydroxyethoxyphenylsulfonio)] phenyl sulfide-bis-hexafluorophosphonate.
The iodonium salt is not particularly limited, and examples thereof include diphenyliodonium trifluoromethyl sulfonate, diphenyliodonium p-toluenesulfonate, diphenyliodonium tetrafluoroborate, diphenyliodonium hexafluoroarsenate, and diphenyliodonium hexafluorophosphonate.
The sulfonic acid esters are not particularly limited. For example, methyl p-toluenesulfonate, ethyl p-toluenesulfonate, butyl p-toluenesulfonate, phenyl p-toluenesulfonate, 1,2,3-tri (p -Toluenesulfonyloxy) benzene, p-toluenesulfonic acid benzoin ester, methyl methanesulfonate, ethyl methanesulfonate, butyl methanesulfonate, 1,2,3-tri (methanesulfonyloxy) benzene, phenyl methanesulfonate, methane Sulfonic acid benzoin ester, methyl trifluoromethanesulfonate, ethyl trifluoromethanesulfonate, butyl trifluoromethanesulfonate, 1,2,3-tri (trifluoromethanesulfonyloxy) benzene, phenyl trifluoromethanesulfonate Trifluoromethanesulfonic acid benzoin ester.
The oxime sulfonates are not particularly limited, and examples include α- (p-chlorobenzenesulfonyloxyimino) phenylacetonitrile.
The disulfones are not particularly limited, and examples thereof include diphenyl disulfone.
The carbonylsulfonyldiazomethanes are not particularly limited, and examples thereof include phenylcarbonylphenylsulfonyldiazomethane.
The bissulfonylmethanes are not particularly limited, and examples thereof include bis (phenylsulfonyl) methane and bis (cyclohexylsulfonyl) methane.
The bissulfonyldiazomethanes are not particularly limited. For example, bis (phenylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, (cyclohexylsulfonyl) (4-methoxyphenylsulfonyl) diazomethane, (cyclohexylsulfonyl) (2-naphthylsulfonyl) And diazomethane.
The o-nitrobenzyl esters are not particularly limited, and examples thereof include o-nitrobenzyl-p-toluenesulfonate.
The sulfone hydrazides are not particularly limited, and examples thereof include N, N′-di (phenylsulfonyl) hydrazide.
The iminosulfonates are not particularly limited, and examples thereof include phthaliminotrifluoromethylsulfonate, phthalimino p-toluenesulfonate, and phthaliminocamphorsulfonate.
Among the photoacid generators, compounds that generate sulfonic acid after exposure are preferable.

Although content of the said photo-acid generator (B) is not specifically limited, A preferable minimum is 1 weight part and a preferable upper limit is 10 weight part with respect to 100 weight part of resin (A) which has the said acyclic acetal structural unit. is there. When the content of the photoacid generator (B) is less than 1 part by weight, it may take time to develop the resist pattern. When content of the said photo-acid generator (B) exceeds 10 weight part, the time concerning thermal decomposition of the negative photosensitive composition obtained may become long. The minimum with more preferable content of the said photo-acid generator (B) is 2 weight part, and a more preferable upper limit is 6 weight part.

The positive photosensitive composition of the present invention preferably further contains a decomposition accelerator (C).
The decomposition accelerator (C) has a role of improving the thermal decomposability of the positive photosensitive composition of the present invention. The decomposition accelerator (C) is not particularly limited, and examples thereof include radical generators such as acids, azo compounds, and peroxides.

The acid is not particularly limited, and examples thereof include inorganic acid, phosphoric acid, sulfonic acid, and carboxylic acid.
The said inorganic acid is not specifically limited, For example, a sulfuric acid, hydrochloric acid, nitric acid etc. are mentioned.
The phosphoric acid is not particularly limited, and examples thereof include dimethyl phosphoric acid, methyl phosphoric acid, ethyl phosphoric acid, diethyl phosphoric acid, butyl phosphoric acid, dibutyl phosphoric acid, phosphoric acid and the like.
The sulfonic acid is not particularly limited, and examples thereof include methanesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid and the like.
The carboxylic acid is not particularly limited, and examples thereof include acetic acid, lactic acid, butyric acid, butanoic acid, heptanoic acid, 2-ethylhexanoic acid, octylic acid, benzoic acid, and trifluoroacetic acid.
The above acids may be used alone or in combination. Moreover, you may use the compound which has multiple types of different acidic group in 1 molecule.

The azo compound is not particularly limited. For example, azobisisobutyronitrile (AIBN), 2,2-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2-azobis (2-cyclohexane) Propylpropionitrile), 2,2-azobis (2-methylbutyronitrile), 1,1-azobis (cyclohexane-1-carbonitrile) and the like.

The peroxide is not particularly limited, and examples thereof include hydrogen peroxide, potassium persulfate, sodium persulfate, and organic peroxides.
The organic peroxide is not particularly limited, but when it is necessary to impart storage stability to the positive photosensitive composition of the present invention, an organic peroxide having a 10-hour half-life temperature of 100 ° C. or higher is used. It is preferable to use it.
The organic peroxide having a 10-hour half-life temperature of 100 ° C. or higher is not particularly limited, and examples thereof include hydroxy peroxide, dialkyl peroxide, peroxy ketal, and peroxy ester.

The hydroxy peroxide is not particularly limited, and examples thereof include P-menthane hydroxy peroxide, diisopropylbenzene hydroxy peroxide, 1,1,3,3-tetramethylbutyl hydroxy peroxide, cumene hydroxy peroxide, t-hexyl hydroxyperoxide. Examples thereof include oxide and t-butylhydroxyperoxide.
The dialkyl peroxide is not particularly limited, and examples thereof include dicumyl peroxide, α, α′-bis (t-butylperoxy-m-isopropylbenzene), 2,5-dimethyl-2,5-bis (t- Butylperoxy) hexane, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3, and the like.
The peroxyketal is not particularly limited. For example, 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, , 1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) cyclododecane, 2,2-bis (t-butylperoxy) butane, n-butyl 4,4-bis (t-butylperoxy) valerate, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) Examples include propane.
The peroxyester is not particularly limited. For example, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy3,5,5-trimethylhexanoate, t-butylperoxy Laurate, 2,5-dimethyl-2,5-bis (m-toluylperoxy) hexane, t-butylperoxyisopropyl monocarbonate, t-hexylperoxybenzoate, 2,5-dimethyl-2,5-bis (M-Benzoylperoxy) hexane, t-butylperoxyacetate, t-butylperoxybenzoate, bis-t-butylperoxyisophthalate, t-butylperoxyallyl monocarbonate and the like.

The content of the decomposition accelerator (C) is not particularly limited, but a preferable lower limit is 0.1 parts by weight and a preferable upper limit is 10 parts by weight with respect to 100 parts by weight of the resin (A) having the acyclic acetal structural unit. It is. When the content of the decomposition accelerator (C) is less than 0.1 parts by weight, the effect of improving the thermal decomposability of the positive photosensitive composition of the present invention may not be sufficiently obtained. If the content of the decomposition accelerator (C) exceeds 10 parts by weight, the dimension of the resist pattern may not be stable. The minimum with more preferable content of the said decomposition accelerator (C) is 1 weight part, and a more preferable upper limit is 5 weight part.

The positive photosensitive composition of the present invention preferably further contains a solubility inhibitor (D). The solubility inhibitor (D) is a compound that acts as a base with respect to an acid, and has a role to prevent the acid generated during exposure or pre-baking from moving to change the size of the resist pattern.

The solubility inhibitor (D) is not particularly limited as long as it is a compound that neutralizes the acid generated from the photoacid generator (B), and examples thereof include organic amine compounds. Specific examples include pyrimidine compounds, pyridine compounds, amines substituted with a hydroxyalkyl group having 1 to 4 carbon atoms, and aminophenols.

The pyrimidine compounds are not particularly limited. For example, pyrimidine, 2-aminopyrimidine, 4-aminopyrimidine, 5-aminopyrimidine, 2,4-diaminopyrimidine, 2,5-diaminopyrimidine, 4,5-diaminopyrimidine, 4,6-diaminopyrimidine, 2,4,5-triaminopyrimidine, 2,4,6-triaminopyrimidine, 4,5,6-triaminopyrimidine, 2,4,5,6-tetraaminopyrimidine, 2 -Hydroxypyrimidine, 4-hydroxypyrimidine, 5-hydroxypyrimidine, 2,4-dihydroxypyrimidine, 2,5-dihydroxypyrimidine, 4,5-dihydroxypyrimidine, 4,6-dihydroxypyrimidine, 2,4,5-trihydroxy Pyrimidine, 2,4,6-trihydroxypyrimidine, 4, , 6-trihydroxypyrimidine, 2,4,5,6-tetrahydroxypyrimidine, 2-amino-4-hydroxypyrimidine, 2-amino-5-hydroxypyrimidine, 2-amino-4,5-dihydroxypyrimidine, 2- Amino-4,6-dihydroxypyrimidine, 4-amino-2,5-dihydroxypyrimidine, 4-amino-2,6-dihydroxypyrimidine, 2-amino-4-methylpyrimidine, 2-amino-5-methylpyrimidine, 2 -Amino-4,5-dimethylpyrimidine, 2-amino-4,6-dimethylpyrimidine, 4-amino-2,5-dimethylpyrimidine, 4-amino-2,6-dimethylpyrimidine, 2-amino-4-methoxy Pyrimidine, 2-amino-5-methoxypyrimidine, 2-amino-4,5-dimethoxypyrimidine 2-amino-4,6-dimethoxypyrimidine, 4-amino-2,5-dimethoxypyrimidine, 4-amino-2,6-dimethoxypyrimidine, 2-hydroxy-4-methylpyrimidine, 2-hydroxy-5 Methylpyrimidine, 2-hydroxy-4,5-dimethylpyrimidine, 2-hydroxy-4,6-dimethylpyrimidine, 4-hydroxy-2,5-dimethylpyrimidine, 4-hydroxy-2,6-dimethylpyrimidine, 2-hydroxy -4-methoxypyrimidine, 2-hydroxy-4-methoxypyrimidine, 2-hydroxy-5-methoxypyrimidine, 2-hydroxy-4,5-dimethoxypyrimidine, 2-hydroxy-4,6-dimethoxypyrimidine, 4-hydroxy- 2,5-dimethoxypyrimidine, 4-hydroxy-2,6-di And methoxypyrimidine.

The pyridine compounds are not particularly limited, and examples thereof include pyridine, methylpyridine, N, N-dimethylaminopyridine, 2,6-dimethylpyridine and the like.

The amines substituted with a hydroxyalkyl group having 1 to 4 carbon atoms are not particularly limited. For example, diethanolamine, triethanolamine, triisopropanolamine, tris (hydroxymethyl) aminomethane, bis (2-hydroxyethyl) Examples include iminotris (hydroxymethyl) methane.

The said aminophenol is not specifically limited, For example, 2-aminophenol, 3-aminophenol, 4-aminophenol etc. are mentioned.

Although content of the said solubility inhibitor (D) is not specifically limited, A preferable minimum is 0.1 mol% with respect to content of the said photo-acid generator (B), and a preferable upper limit is 100 mol%. When the content of the solubility inhibitor (D) is less than 0.1 mol%, the effect of neutralizing the acid generated from the photoacid generator (B) cannot be sufficiently obtained, and at the time of exposure or prebaking The generated acid may move to change the dimension of the resist pattern. When the content of the solubility inhibitor (D) exceeds 100 mol%, it may take time to develop the resist pattern. The minimum with more preferable content of the said solubility inhibitor (D) is 1 mol%, and a more preferable upper limit is 50 mol%.

The positive photosensitive composition of the present invention preferably further contains a solvent.
The solvent is not particularly limited, and propylene carbonate, tetrahydrofuran, ethylene glycol ethyl ether, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoisobutyl ether, trimethylpentanediol monoisobutyrate. Butyl carbitol, butyl carbitol acetate, terpineol, terpineol acetate, dihydroterpineol, dihydroterpineol acetate texanol, isophorone, butyl lactate, dioctyl phthalate, dioctyl adipate, benzyl alcohol, phenylpropylene glycol, cresol, propylene glycol Monomethyl ether acetate and the like.
Among them, terpineol acetate, dihydroterpineol, dihydroterpineol acetate, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoisobutyl ether, butyl carbitol, butyl carbitol acetate, texanol, propylene glycol monomethyl ether acetate are preferable, terpineol, terpineol acetate Dihydroterpineol, dihydroterpineol acetate, and propylene glycol monomethyl ether acetate are more preferable. In addition, these organic solvents may be used independently and may use 2 or more types together.
The organic solvent preferably has a boiling point of 100 ° C. or higher. If it is lower than 100 ° C., the solvent may be volatilized during the process of applying the sinterable resist composition, which may make it impossible to apply.

Although content of the said solvent is not specifically limited, A preferable minimum is 1 weight part with respect to 100 weight part with respect to 100 weight part of resin (A) which has the said acyclic acetal structural unit, A preferable upper limit is 200 weight part It is. When the content of the solvent is less than 1 part by weight, the viscosity becomes too high, so that application may not be possible. When the content of the solvent exceeds 200 parts by weight, the time for drying the solvent may become long. The more preferable lower limit of the content of the solvent is 5 parts by weight, and the more preferable upper limit is 100 parts by weight.

The positive photosensitive composition of the present invention can be used as necessary in plasticizers, dispersants, leveling agents, water repellents, oil repellents, antifoaming agents, lubricants, peptizers, mold release agents, sintering aids. Contains additives such as additives, antistatic agents, antiseptics, antibacterial agents, thixo materials, diluents, thickeners, UV absorbers, antioxidants, foaming agents, corrosion inhibitors, compatibilizers, and volatilizers May be. These additives may be used alone or in combination of two or more.

The method for producing the positive photosensitive composition of the present invention is not particularly limited, and includes conventionally known stirring methods. Specifically, for example, the resin (A) having the acyclic acetal structural unit and the photoacid Examples include a method of stirring the generator (B) and other components added as necessary. The stirring method is not particularly limited. For example, stirring is performed using a two-roll mill, a three-roll mill, a bead mill, a ball mill, a disper, a planetary mixer, a rotation / revolution stirrer, a kneader, an extruder, a mix rotor, a stirrer, or the like. And the like.
Further, during stirring, the pressure may be reduced to remove bubbles, or the temperature of the positive photosensitive composition may be adjusted as appropriate in order to increase the mixing efficiency.

The residual rate (hereinafter also referred to as 300 ° C. residual rate) when the positive photosensitive composition of the present invention is heated to 300 ° C. at a rate of temperature increase of 10 ° C./min is not particularly limited, but a preferred upper limit is 10%. . When the 300 ° C. residual ratio exceeds 10%, when the positive photosensitive composition of the present invention is used as a resist material, it may be necessary to increase the temperature in order to remove the resist.

The method for applying the positive photosensitive composition of the present invention is not particularly limited. For example, spin coating, spray coating, bar coating, die coating, curtain coating, roll coating, casting, screen printing Method, offset printing method, gravure printing method, flexographic printing, stencil printing method, micro gravure printing method, ink jet printing method, dispenser method, stamp method, imprint method and the like.

Although the use of the positive photosensitive composition of the present invention is not particularly limited, it can be used for semiconductors, liquid crystals, MEMS and the like.

A method for forming a conductive pattern using the positive photosensitive composition of the present invention is also one aspect of the present invention.
The method for forming a conductive pattern of the present invention includes a step of forming a resist pattern on a substrate by performing a photolithography process using the positive photosensitive composition of the present invention.

The following method is suitably used for the photolithography process.
That is, first, the positive photosensitive composition of the present invention is coated on a substrate by a conventionally known method such as a screen printing method, a curtain coating method, a spin coating method, or a spray coating method, and a resist having a predetermined thickness is applied. Form a layer.
In addition, the positive photosensitive composition of the present invention was formed into a sheet in advance instead of the method of coating the positive photosensitive composition of the present invention on a substrate and forming a resist layer having a predetermined thickness. A method of attaching a resist sheet on a substrate may be used. The method for producing the resist sheet is not particularly limited. For example, the resist solution is applied on the release sheet so as to have a predetermined thickness to form a resist layer having a predetermined thickness. Examples include a peeling method.

Next, the resist layer is exposed to ultraviolet rays using a positive mask that covers only the portion to be patterned.
Although the exposure amount of the said ultraviolet-ray is not specifically limited, 100-10,000 mJ / cm < ² > is preferable.

Then, using a developing solution such as a dilute alkaline aqueous solution (for example, 1% sodium carbonate aqueous solution, 1% caustic soda aqueous solution, etc.), water, or an ethanol solution at a liquid temperature of 10 to 60 ° C., development is performed by means such as spraying. Thus, a resist pattern having a predetermined pattern can be formed.

The said board | substrate is not specifically limited, For example, liquid crystal substrates, such as semiconductor substrates, such as a silicon wafer, a glass plate, etc. are mentioned.

The conductive pattern forming method of the present invention includes a step of forming a conductor film on a resist pattern formed on a substrate.

Although the material which comprises the said conductor film will not be specifically limited if it has electroconductivity, For example, metals, such as tungsten, gold | metal | money, copper, are used suitably.

The method for forming the conductor film is not particularly limited, and conventionally known methods such as sputtering, vapor deposition, and plating can be used.

The conductive pattern forming method of the present invention includes a step of decomposing and removing the resist pattern by heat treatment.

The method for performing the heat treatment is not particularly limited, and examples thereof include a method using a hot plate, a heating press apparatus, a drying oven, a heat gun, an infrared heating apparatus, a dielectric heating apparatus, an induction heating apparatus, an ultrasonic heating apparatus, and the like.

The heat treatment can also be performed in an inert gas. By performing the heat treatment in an inert gas, the conductor film can be prevented from being oxidized.
The inert gas is not particularly limited, and examples thereof include nitrogen, helium, and argon.

The heating temperature in the step of decomposing and removing the resist pattern by the heat treatment is not particularly limited, but a preferred lower limit is 250 ° C. and a preferred upper limit is 300 ° C. If the heating temperature is less than 250 ° C., the resist pattern may not be sufficiently decomposed and may remain on the substrate. When the heating temperature exceeds 300 ° C., the substrate may be damaged by heat.

According to the present invention, it is possible to provide a positive photosensitive composition that can be decomposed and removed at a low temperature when used as a resist material and has a very small amount of undecomposed components. Moreover, according to this invention, the formation method of the conductive pattern which uses this positive photosensitive composition can be provided.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

Example 1
In a 2 L separable flask equipped with a stirrer, cooler, thermometer, hot water bath and nitrogen gas inlet,
100 parts by weight of fully dehydrated tetrahydrofuran and 100 parts by weight of fully dehydrated 4-hydroxybutyl vinyl ether (manufactured by Maruzen Petrochemical Co., Ltd.) were added, stirred, cooled to 0 ° C., and then paratoluenesulfonic acid monohydrate. 10 parts by weight of a 1% ethyl acetate solution of the product was slowly added dropwise while paying attention to heat generation. After dripping, it was made to react for 5 hours. After confirming that the peak in the vicinity of 3500 cm ⁻¹ derived from a hydroxyl group had almost disappeared by infrared absorption analysis (IR), distilled water was added to stop the reaction. Thereafter, 10 parts by weight of an ion exchange resin (manufactured by Organo Corporation, “IRA 96SB AG”) was added to remove paratoluenesulfonic acid. Finally, the ion exchange resin was filtered to obtain a resin (A) having an acyclic acetal structural unit.

Next, 100 parts by weight of the resin (A) having an acyclic acetal structural unit obtained, 20 parts by weight of propylene carbonate as a solvent, 130 parts by weight of propylene glycol monomethyl ether acetate, and as a photoacid generator (B) 4,4 ′-[di (β-hydroxyethoxyphenylsulfonio)] phenyl sulfide-bis-hexafluorophosphonate (manufactured by ADEKA, “Adekaoptomer SP150”) 4 parts by weight was added to form a positive photosensitive composition I got a thing.

The obtained positive photosensitive composition was applied onto a silicon wafer by spin coating. Next, the solvent is dried by pre-baking on a hot plate at 120 ° C. for 4 minutes, and using a positive photomask of L / S (line and space) 100 μm / 100 μm, an ultrahigh pressure mercury lamp is used for 500 mJ / cm ² . UV irradiation was performed, and then development was performed using a mixed solution of 50 parts by weight of ethanol and 50 parts by weight of an aqueous 2.38 mass% tetramethylammonium hydroxide to form a resist pattern on the silicon wafer. Next, a thin copper layer was formed by vapor deposition. Then, heat treatment at 300 ° C. is performed in a nitrogen atmosphere, and the resist pattern is thermally decomposed and completely disappeared to lift off the metal portion on the resist pattern, and is made of a copper electrode having L / S of 100 μm / 100 μm. A conductive pattern was formed.

(Example 2)
In a 2 L separable flask equipped with a stirrer, cooler, thermometer, hot water bath and nitrogen gas inlet,
100 parts by weight of fully dehydrated ethyl acetate and 100 parts by weight of fully dehydrated 4-hydroxybutyl vinyl ether (manufactured by Maruzen Petrochemical Co., Ltd.) were stirred and cooled to 0 ° C. 20 parts by weight of a 1% ethyl acetate solution of the Japanese product was slowly added dropwise while paying attention to heat generation. After dripping, it was made to react for 4 hours. After confirming that the peak in the vicinity of 3500 cm ⁻¹ derived from a hydroxyl group has almost disappeared by infrared absorption analysis (IR), ammonia water and a saturated aqueous sodium chloride solution were added, and a resin solution having an acyclic acetal structural unit was obtained. Extracted. Finally, ethyl acetate was removed by reducing the pressure to obtain a resin (A) having an acyclic acetal structural unit.

Next, 100 parts by weight of the resin (A) having an acyclic acetal structural unit obtained, 20 parts by weight of propylene carbonate as a solvent, 130 parts by weight of propylene glycol monomethyl ether acetate, and as a photoacid generator (B) 4,4 ′-[di (β-hydroxyethoxyphenylsulfonio)] phenyl sulfide-bis-hexafluorophosphonate (Adeka Optomer SP150, manufactured by Asahi Denka Kogyo Co., Ltd.) and 4 parts by weight of the positive photosensitive composition I got a thing.
Next, a conductive pattern was formed on a silicon wafer in the same manner as in Example 1 using the obtained positive photosensitive composition.

(Example 3)
In addition to 100 parts by weight of fully dehydrated ethyl acetate and 100 parts by weight of fully dehydrated 4-hydroxybutyl vinyl ether, a 2 L separate flask equipped with a stirrer, cooler, thermometer, hot water bath and nitrogen gas inlet A resin (A) having an acyclic acetal structural unit and a positive photosensitive composition were obtained in the same manner as in Example 2 except that 0.4 parts by weight of distilled water was added.
Next, a conductive pattern was formed on a silicon wafer in the same manner as in Example 1 using the obtained positive photosensitive composition.

Example 4
Instead of 100 parts by weight of fully dehydrated 4-hydroxybutyl vinyl ether 40 weights of fully dehydrated 4-hydroxybutyl vinyl ether in a 2 L separable flask equipped with a stirrer, cooler, thermometer, hot water bath and nitrogen gas inlet And a resin (A) having an acyclic acetal structural unit in the same manner as in Example 2 except that 60 parts by weight of fully-dehydrated cyclohexyldimethanol monovinyl ether (manufactured by BASF) was added, and positive type A photosensitive composition was obtained.
Next, a conductive pattern was formed on a silicon wafer in the same manner as in Example 1 using the obtained positive photosensitive composition.

(Example 5)
In place of 100 parts by weight of fully dehydrated 4-hydroxybutyl vinyl ether, fully dehydrated 1,4-butanediol dihydrate in a 2 L separable flask equipped with a stirrer, cooler, thermometer, hot water bath and nitrogen gas inlet Resin (A) having an acyclic acetal structural unit in the same manner as in Example 1 except that 61 parts by weight of vinyl ether and 39 parts by weight of fully dehydrated 1,4-butanediol were added, and positive photosensitive Sex composition was obtained.
Next, a conductive pattern was formed on a silicon wafer in the same manner as in Example 1 using the obtained positive photosensitive composition.

(Example 6)
In place of 100 parts by weight of fully dehydrated 4-hydroxybutyl vinyl ether, 1,4-cyclohexyldimethanol sufficiently dehydrated in a 2 L separable flask equipped with a stirrer, cooler, thermometer, hot water bath and nitrogen gas inlet Example 1 was repeated except that 38 parts by weight of monovinyl ether, 38 parts by weight of sufficiently dehydrated 1,4-butanediol divinyl ether and 24 parts by weight of sufficiently dehydrated 1,4-butanediol were added. Thus, a resin (A) having an acyclic acetal structural unit and a positive photosensitive composition were obtained.
Next, a conductive pattern was formed on a silicon wafer in the same manner as in Example 1 using the obtained positive photosensitive composition.

(Example 7)
In the same manner as in Example 2, a resin (A) having an acyclic acetal structural unit was obtained. Positive type in the same manner as in Example 2, except that 20 parts by weight of tetrahydrofuran was used instead of 20 parts by weight of propylene carbonate, and 4 parts by weight of α- (p-chlorobenzenesulfonyloxyimino) phenylacetonitrile was used as the photoacid generator. A photosensitive composition was obtained.
Next, a conductive pattern was formed on a silicon wafer in the same manner as in Example 1 using the obtained positive photosensitive composition.

(Comparative Example 1)
Instead of 100 parts by weight of the acetal resin (A) having an acyclic acetal structural unit, 100 parts by weight of a positive resist (manufactured by Tokyo Ohka Kogyo Co., Ltd., “THMR-iP3000”) was added, and the components described in Table 1 were added. A mold photosensitive composition was obtained.
Next, a conductive pattern was formed on a silicon wafer in the same manner as in Example 1 using the obtained positive photosensitive composition.

<Evaluation>
The following evaluation was performed about resin (A) which has the acyclic acetal structural unit obtained by the Example and the comparative example, positive photosensitive composition, and a resist pattern. The results are shown in Table 1.

(1) Number average molecular weight The resin (A) having an acyclic acetal structural unit obtained in the examples is analyzed by gel permeation chromatography (GPC) using LF-804 (manufactured by SHOKO) as a column. Thus, the number average molecular weight in terms of polystyrene was measured.

(2) Pattern thickness About the resist pattern obtained by the Example and the comparative example, pattern thickness was measured using the surface roughness shape measuring instrument "SURFCOM1400D-R" (made by Tokyo Seimitsu Co., Ltd.).

(3) Thermal decomposability (300 ° C residual rate)
With respect to the positive photosensitive compositions obtained in Examples and Comparative Examples, using a thermal decomposition apparatus (“simultaneous SDT 2960” manufactured by TA Instruments) at a heating rate of 10 ° C./min in air and in a nitrogen atmosphere. The residual ratio of the positive photosensitive composition when heated to 300 ° C. was measured.

According to the present invention, it is possible to provide a positive photosensitive composition that can be decomposed and removed at a low temperature when used as a resist material and has a very small amount of undecomposed components. Moreover, according to this invention, the formation method of the conductive pattern which uses this positive photosensitive composition can be provided.

Claims (7)

A positive photosensitive composition containing a resin (A) having an acyclic acetal structural unit and a photoacid generator (B),
The resin (A) having the acyclic acetal structural unit includes a resin (A1) having a structural unit represented by the following general formula (1), and a structural unit represented by the following general formulas (3) and (4). Or resin (A3) having structural units represented by the following general formulas (1), (2), (3) and (4),
The positive photosensitive composition, wherein a ratio of the number of carbon atoms to the number of oxygen atoms in the resin (A) having an acyclic acetal structural unit is 2.3 to 6.0.

In general formulas (1) to (4), R ¹ , R ² , and R ³ represent a divalent organic group, a to d represent an integer of 1 or more, and c / d is 0.8. ~ 1.2. ^2. The positive type according to claim ¹ , wherein R ¹ , R ² , and R ³ are at least one selected from the group consisting of structural units represented by the following general formulas (5) to (14): Photosensitive composition.

e represents an integer of 3 or more, and f and g represent an integer of 1 or more. The positive photosensitive resin according to claim 1 or 2, wherein the resin (A) having an acyclic acetal structural unit has a number average molecular weight in terms of polystyrene measured by gel permeation chromatography of 1,000 to 1,000,000. Composition. The photoacid generator (B) includes halogen-containing s-triazine derivatives, halogen-substituted paraffin hydrocarbons, halogen-substituted cycloparaffin hydrocarbons, halogen-containing benzene derivatives, halogen-containing sulfone compounds, halogen-containing isocyanurate derivatives, sulfonium salts, From the group consisting of iodonium salts, oxime sulfonates, sulfonate esters, disulfones, carbonylsulfonyldiazomethanes, bissulfonylmethanes, bissulfonyldiazomethanes, o-nitrobenzyl esters, sulfone hydrazides, and iminosulfonates The positive photosensitive composition according to claim 1, wherein the positive photosensitive composition is at least one selected. The positive photosensitive composition according to claim 1, 2, 3, or 4, further comprising a decomposition accelerator (C). Furthermore, a solubility inhibitor (D) is contained, The positive photosensitive composition of Claim 1, 2, 3, 4 or 5 characterized by the above-mentioned. A step of forming a resist pattern on a substrate by performing a photolithography process using the positive photosensitive composition according to claim 1, and a conductor on the resist pattern formed on the substrate A method for forming a conductive pattern, comprising: a step of forming a film; and a step of decomposing and removing the resist pattern by heat treatment.