JP5498874B2 - Positive photosensitive resin composition - Google Patents

Description

  The present invention relates to a positive photosensitive resin composition, and more particularly to a positive photosensitive resin composition used for an interlayer insulating film, a surface protective film and the like of a semiconductor element.

  Conventionally, polyimide-based resins having excellent heat resistance, mechanical properties, and the like have been widely used for interlayer insulating films, surface protective films, and the like used in semiconductor devices of electronic devices. In addition, in order to improve productivity and film formation accuracy, a photosensitive polyimide resin imparted with photosensitivity has been studied. For example, Patent Documents 1 and 2 disclose positive photosensitive compositions containing a polyimide precursor and an orthoquinonediazide compound. However, these positive photosensitive compositions have problems in heat resistance, electrical insulation, adhesion to the substrate, and the like.

  Therefore, in Patent Document 3, a positive photosensitive resin containing an alkali-soluble resin having a phenolic hydroxyl group, a compound having a quinonediazide group, a crosslinked fine particle, a compound having at least two alkyl etherified amino groups in the molecule, and a solvent. Insulating resin compositions have been proposed. According to this positive type photosensitive insulating resin composition, a cured product having good resolution, electrical insulating properties, adhesion to a substrate, and the like can be obtained. Such hardened | cured material is used as a permanent insulating film in a semiconductor element, for example.

JP-A-5-5996 JP 2000-98601 A JP 2003-215789 A

  By the way, in recent years, with the progress of miniaturization of integrated circuits, the distance between wirings in integrated circuits has become closer, and a photosensitive resin composition and a cured product thereof exhibiting a higher level of resolution and electrical insulation characteristics. It has been demanded. Moreover, the hardened | cured material produced with the positive photosensitive resin composition described in said each patent document has a hard and brittle property, and there was room for improvement as a permanent insulating film in a semiconductor element.

  The present invention has been made in view of the above situation, and provides a positive photosensitive resin composition that exhibits good resolution and good electrical insulation characteristics and strength in a cured product thereof. Objective.

  The inventors added an acrylic resin having a structural unit having a specific structure to a positive photosensitive resin composition containing an alkali-soluble resin having a phenolic hydroxyl group and a compound having a quinonediazide group. The present inventors have found that a cured product produced from the composition exhibiting good resolution and good electrical insulation properties and strength, and completed the present invention.

（上記一般式（１）中、Ｒ^１は水素原子又はアルキル基を表し、Ｒ^２は独立に炭化水素基を表し、ｐは０〜３を表す。） The present invention includes (A) an alkali-soluble resin having a phenolic hydroxyl group, (B) a compound having a quinonediazide group, (C) a compound having at least two alkyl etherified amino groups in the molecule, (D) An acrylic resin containing a structural unit (d1) represented by the formula (1) and a structural unit (d2) derived from an unsaturated carboxylic acid, and having a mass average molecular weight of 20,000 to 500,000, and (S) a solvent A positive photosensitive resin composition to be contained.

(In the general formula (1), R ¹ represents a hydrogen atom or an alkyl group, R ² independently represents a hydrocarbon group, and p represents 0 to 3).

  According to the present invention, a positive photosensitive resin composition is provided that exhibits good resolution and good electrical insulation properties and strength in a cured product thereof.

Hereinafter, an embodiment of the positive photosensitive resin composition of the present invention will be described.
The positive photosensitive resin composition according to the present embodiment includes (A) an alkali-soluble resin having a phenolic hydroxyl group, (B) a compound having a quinonediazide group, and (C) at least two alkyl etherified amino acids in the molecule. A compound having a group, (D) an acrylic resin having a structural unit having a specific structure and a weight average molecular weight of 20,000 to 500,000, and (S) a solvent. Hereinafter, each component contained in the positive photosensitive resin composition according to the present invention will be described in detail.

[(A) Alkali-soluble resin having phenolic hydroxyl group]
The alkali-soluble resin having a phenolic hydroxyl group (hereinafter also referred to as “component (A)”) is not particularly limited, but a novolak resin is preferable. Such a novolak resin can be obtained by addition condensation of phenols and aldehydes in the presence of an acid catalyst.

Examples of the phenols include phenol; cresols such as o-cresol, m-cresol, and p-cresol; 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, Xylenols such as 3,4-xylenol and 3,5-xylenol; o-ethylphenol, m-ethylphenol, p-ethylphenol, 2-isopropylphenol, 3-isopropylphenol, 4-isopropylphenol, o-butylphenol, alkylphenols such as m-butylphenol, p-butylphenol and p-tert-butylphenol; trialkylphenols such as 2,3,5-trimethylphenol and 3,4,5-trimethylphenol; resorcinol, catechol, hydroxy Polyhydric phenols such as chloroquinone, hydroquinone monomethyl ether, pyrogallol, and phloroglicinol; alkyl polyhydric phenols such as alkylresorcin, alkylcatechol, and alkylhydroquinone (all alkyl groups have 1 to 4 carbon atoms); α- Examples include naphthol, β-naphthol, hydroxydiphenyl, bisphenol A and the like. These phenols may be used alone or in combination of two or more.
Among these phenols, m-cresol and p-cresol are preferable, and it is more preferable to use m-cresol and p-cresol in combination. In this case, various characteristics such as sensitivity and heat resistance can be adjusted by adjusting the blending ratio of the two.

  Examples of the aldehydes include formaldehyde, paraformaldehyde, furfural, benzaldehyde, nitrobenzaldehyde, and acetaldehyde. These aldehydes may be used alone or in combination of two or more.

  Examples of the acid catalyst include inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, and phosphorous acid; organic acids such as formic acid, oxalic acid, acetic acid, diethylsulfuric acid, and paratoluenesulfonic acid; and metal salts such as zinc acetate. Can be mentioned. These acid catalysts may be used alone or in combination of two or more.

  Specific examples of the novolak resin thus obtained include phenol / formaldehyde condensed novolak resin, cresol / formaldehyde condensed novolak resin, phenol-naphthol / formaldehyde condensed novolak resin, and the like.

  Examples of alkali-soluble resins having phenolic hydroxyl groups other than novolak resins include polyhydroxystyrene and copolymers thereof, phenol-xylylene glycol condensed resins, cresol-xylylene glycol condensed resins, phenol-dicyclopentadiene condensed resins, etc. Is mentioned.

  The mass average molecular weight of these resins is preferably 1000 to 50000 from the viewpoints of resolution, thermal shock resistance of the resulting cured product, heat resistance, and the like.

The content of the component (A) is preferably 45 to 90% by mass and more preferably 50 to 80% by mass with respect to the solid content of the positive photosensitive resin composition. By making content of (A) component into the said range, the developability of positive type photosensitive resin composition can be made favorable.
Further, the content of the component (A) is preferably 70 to 90 parts by mass, and 80 to 88 parts by mass when the total of the component (A) and the component (D) described later is 100 parts by mass. Preferably there is. It is preferable for it to be in the above-mentioned range since it is excellent in chemical resistance and resolution.

[(B) Compound having quinonediazide group]
The compound having a quinonediazide group (hereinafter also referred to as “component (B)”) is not particularly limited, but is a complete esterified product or partial ester of a compound having one or more phenolic hydroxyl groups and a quinonediazide group-containing sulfonic acid. Compounds are preferred. Such a compound having a quinonediazide group is obtained by combining a compound having one or more phenolic hydroxyl groups and a sulfonic acid having a quinonediazide group in a suitable solvent such as dioxane, such as triethanolamine, carbonate, bicarbonate, etc. It can be obtained by condensation in the presence of an alkali compound and complete esterification or partial esterification.

Examples of the compound having one or more phenolic hydroxyl groups include polyhydroxybenzophenones such as 2,3,4-trihydroxybenzophenone and 2,3,4,4′-tetrahydroxybenzophenone;
Tris (4-hydroxyphenyl) methane, bis (4-hydroxy-3-methylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,3,5-trimethylphenyl) -2-hydroxyphenylmethane, Bis (4-hydroxy-3,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3-hydroxyphenylmethane, bis (4-hydroxy-3,5- Dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3-hydroxyphenylmethane, Bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyl Nylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, bis (4- Hydroxy-2,5-dimethylphenyl) -2,4-dihydroxyphenylmethane, bis (4-hydroxyphenyl) -3-methoxy-4-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) ) -4-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -2-hydroxyphenyl Methane, bis (5-cyclohexyl-4-hydro Shi-2-methylphenyl) -3,4-trisphenol compounds such dihydroxyphenyl methane;
Linear type 3 such as 2,4-bis (3,5-dimethyl-4-hydroxybenzyl) -5-hydroxyphenol, 2,6-bis (2,5-dimethyl-4-hydroxybenzyl) -4-methylphenol Nuclear phenolic compounds;
1,1-bis [3- (2-hydroxy-5-methylbenzyl) -4-hydroxy-5-cyclohexylphenyl] isopropane, bis [2,5-dimethyl-3- (4-hydroxy-5-methylbenzyl) ) -4-hydroxyphenyl] methane, bis [2,5-dimethyl-3- (4-hydroxybenzyl) -4-hydroxyphenyl] methane, bis [3- (3,5-dimethyl-4-hydroxybenzyl)- 4-hydroxy-5-methylphenyl] methane, bis [3- (3,5-dimethyl-4-hydroxybenzyl) -4-hydroxy-5-ethylphenyl] methane, bis [3- (3,5-diethyl- 4-hydroxybenzyl) -4-hydroxy-5-methylphenyl] methane, bis [3- (3,5-diethyl-4-hydroxybenzyl) -4- Loxy-5-ethylphenyl] methane, bis [2-hydroxy-3- (3,5-dimethyl-4-hydroxybenzyl) -5-methylphenyl] methane, bis [2-hydroxy-3- (2-hydroxy-) 5-methylbenzyl) -5-methylphenyl] methane, bis [4-hydroxy-3- (2-hydroxy-5-methylbenzyl) -5-methylphenyl] methane, bis [2,5-dimethyl-3- ( Linear tetranuclear phenolic compounds such as 2-hydroxy-5-methylbenzyl) -4-hydroxyphenyl] methane;
2,4-bis [2-hydroxy-3- (4-hydroxybenzyl) -5-methylbenzyl] -6-cyclohexylphenol, 2,4-bis [4-hydroxy-3- (4-hydroxybenzyl) -5 Linear type 5 such as -methylbenzyl] -6-cyclohexylphenol and 2,6-bis [2,5-dimethyl-3- (2-hydroxy-5-methylbenzyl) -4-hydroxybenzyl] -4-methylphenol Nuclear phenolic compounds;
Bis (2,3,4-trihydroxyphenyl) methane, bis (2,4-dihydroxyphenyl) methane, 2,3,4-trihydroxyphenyl-4′-hydroxyphenylmethane, 2- (2,3,4) -Trihydroxyphenyl) -2- (2 ', 3', 4'-trihydroxyphenyl) propane, 2- (2,4-dihydroxyphenyl) -2- (2 ', 4'-dihydroxyphenyl) propane, 2 -(4-hydroxyphenyl) -2- (4'-hydroxyphenyl) propane, 2- (3-fluoro-4-hydroxyphenyl) -2- (3'-fluoro-4'-hydroxyphenyl) propane, 2- (2,4-dihydroxyphenyl) -2- (4′-hydroxyphenyl) propane, 2- (2,3,4-trihydroxyphenyl) -2- (4′-hydroxyphenyl) ) Propane, 2- (2,3,4-trihydroxyphenyl) -2- (4′-hydroxy-3 ′, 5′-dimethylphenyl) propane, 4,4 ′-[1- [4- [1 Bisphenol type compounds such as-(4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] bisphenol;
1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene, 1- [1- (3-methyl-4-hydroxyphenyl) isopropyl]- Polynuclear branched compounds such as 4- [1,1-bis (3-methyl-4-hydroxyphenyl) ethyl] benzene;
And a condensed phenol compound such as 1,1-bis (4-hydroxyphenyl) cyclohexane.
These compounds may be used alone or in combination of two or more.

  Examples of the quinonediazide group-containing sulfonic acid include naphthoquinone-1,2-diazide-5-sulfonic acid, naphthoquinone-1,2-diazide-4-sulfonic acid, and orthoanthraquinonediazidesulfonic acid.

  The content of the component (B) is preferably 5 to 50 parts by mass and more preferably 5 to 25 parts by mass with respect to 100 parts by mass of the component (A). By making content of (B) component into the said range, the sensitivity of positive type photosensitive resin composition can be made favorable.

[(C) Compound having at least two alkyl etherified amino groups in the molecule]
A compound having at least two alkyl etherified amino groups in the molecule (hereinafter also referred to as “component (C)”) is subjected to the above (A) during the heat treatment after development of the positive photosensitive resin composition. It acts as a crosslinking agent that reacts with the components. As this compound, nitrogen containing all or part of active methylol groups such as (poly) methylolated melamine, (poly) methylolated glycoluril, (poly) methylolated benzoguanamine, (poly) methylolated urea, etc. Compounds. Examples of the alkyl group include a methyl group, an ethyl group, a butyl group, or a combination thereof, and may include an oligomer component that is partially self-condensed. Specific examples include hexamethoxymethylated melamine, hexabutoxymethylated melamine, tetramethoxymethylated glycoluril, and tetrabutoxymethylated glycoluril. These compounds may be used alone or in combination of two or more.

  The content of the component (C) is preferably 5 to 60 parts by mass and more preferably 10 to 50 parts by mass with respect to 100 parts by mass of the component (A). By setting the content of the component (C) within the above range, the curability and resolution (patterning characteristics) of the positive photosensitive resin composition, and the electrical insulation and heat resistance of the cured product may be improved. it can.

[(D) Acrylic resin]
The acrylic resin (hereinafter also referred to as “component (D)”) includes a structural unit (d1) represented by the following general formula (1) and a structural unit (d2) derived from an unsaturated carboxylic acid. The structural unit (d1) contained in the component (D) imparts good resolution to the positive photosensitive resin composition, and the strength (breaking elongation) and electrical insulation characteristics (dielectric constant) of the cured product. Improve. That is, in the present invention, by adding the acrylic resin containing the structural unit (d1) to the positive photosensitive composition, the resolution, strength, and dielectric constant of the positive photosensitive composition or its cured product are balanced. It was made based on the knowledge that it can be improved. Further, the structural unit (d2) contained in the component (D) imparts good developability to the positive photosensitive resin composition.

In the general formula (1), R ¹ is a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group. In the general formula (1), R ² is a hydrocarbon group, preferably a chain aliphatic hydrocarbon group, more preferably an alkyl group having 1 to 5 carbon atoms, and still more preferably. Is a methyl group, an ethyl group, a propyl group or a butyl group, particularly preferably an ethyl group. p is 0-3, preferably 0-2. When p is 2 or 3, R ² may be different from each other.

Preferred examples of the structural unit (d1) represented by the general formula (1) are shown below. In the following examples, R ¹ is the same as that in the above formula (1).

  The structural unit (d1) is preferably a structural unit represented by the following general formula (2).

（上記一般式（２）中、Ｒ^１及びＲ^２は、上記一般式（１）におけるものと同様である。）

(In the general formula (2), R ¹ and R ² are the same as those in the general formula (1).)

  The structural unit (d2) is derived from an unsaturated carboxylic acid. When component (D) contains such a structural unit (d2), alkali solubility is imparted to component (D), and good developability is imparted to the positive photosensitive resin composition. In addition, although (D) component is resin to which alkali solubility was provided as mentioned above, it does not correspond to the (A) component already demonstrated.

  Although it does not specifically limit in order to obtain (D) component, The monomer component for introduce | transducing structural unit (d1), The monomer component for introduce | transducing structural unit (d2), Other monomer components as needed Can be copolymerized according to a conventional method. Examples of such copolymerization methods include radical polymerization methods.

Examples of the monomer component for introducing the structural unit (d1) include substituted or unsubstituted hexyl esters of (meth) acrylic acid. Examples of such compounds include cyclohexyl (meth) acrylate, 1-methylcyclohexyl (meth) acrylate, 2-methylcyclohexyl (meth) acrylate, 3-methylcyclohexyl (meth) acrylate, 4-methylcyclohexyl (meth) acrylate, 1 -Ethylcyclohexyl (meth) acrylate, 2-ethylcyclohexyl (meth) acrylate, 3-ethylcyclohexyl (meth) acrylate, 4-ethylcyclohexyl (meth) acrylate, 1-propylcyclohexyl (meth) acrylate, 2-propylcyclohexyl (meth) ) Acrylate, 3-propylcyclohexyl (meth) acrylate, 4-propylcyclohexyl (meth) acrylate, 1-isopropylcyclohexyl (meth) acrylate 1,4-dimethylcyclohexyl (meth) acrylate, 1-ethyl-4-methylcyclohexyl (meth) acrylate, 4-tert-butylcyclohexyl (meth) acrylate, 3,4-dimethylcyclohexyl (meth) acrylate, 2 , 4-dimethylcyclohexyl (meth) acrylate and the like. These monomer components may be used alone or in combination of two or more.
In this specification, the term “(meth) acryl” or “(meth) acrylate” is used to mean “acryl or methacryl” or “acrylate or methacrylate”, respectively.

  Examples of the monomer component for introducing the structural unit (d2) include compounds having an ethylenically unsaturated bond and a carboxyl group. Examples of such compounds include (meth) acrylic acid, vinyl benzoic acid, vinyl acetic acid, α-bromo (meth) acrylic acid, β-furyl (meth) acrylic acid, crotonic acid, propiolic acid, cinnamic acid, α- Examples include cyanocinnamic acid, maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, monoisopropyl maleate, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, and the like. These monomer components may be used alone or in combination of two or more.

Examples of other monomer components include compounds having an ethylenically unsaturated bond. Examples of such compounds include vinyl compounds such as methyl vinyl ether and ethyl vinyl ether; methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meta ) Acrylate, i-butyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-hydroxypropyl ( (Meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-ethylhexyl (meth) ) Acrylate, ethylene glycol mono (meth) acrylate, glycerol (meth) acrylate, dipentaerythritol mono (meth) acrylate, methoxytriethylene glycol (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, Tetrahydrofurfuryl (meth) acrylate, glycidyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-trifluoropropyl (meth) acrylate, dicyclopentanyl (meta And (meth) acrylic ester compounds such as acrylate and adamantyl methacrylate. These monomer components may be used alone or in combination of two or more.
In the present invention, the component (D) is styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate. Nonylphenoxypolyethylene glycol mono (meth) acrylate, nonylphenoxypolypropylene mono (meth) acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-acryloyloxyethyl phthalate, 2-acryloyloxyethyl-2-hydroxyethyl phthalate It is preferable not to contain an aromatic compound such as 2-methacryloyloxyethyl-2-hydroxypropyl phthalate as a monomer.
When the component (D) includes a structural unit derived from the structural unit (d1), the structural unit (d2), and the other monomer components (vinyl compound, (meth) acrylic ester compound) exemplified above, a positive type Since the electrical insulation characteristic (dielectric constant) of the hardened | cured material of the photosensitive resin composition becomes favorable, it is preferable.

  The ratio of the structural unit (d1) to the structural unit (d2) in the component (D) is a molar ratio, preferably 15/1 to 4/1, and more preferably 10/1 to 4/1. In addition, the ratio of the total of the structural unit (d1) and the structural unit (d2) in the component (D) is preferably 30% or more, more preferably 40% or more in terms of molar ratio. The upper limit of the molar ratio may be 100%, preferably 85% or less, more preferably 70% or less. In addition, the ratio of the total of the structural unit (d1) and the structural unit (d2) in the component (D) means that the monomer component for introducing the structural unit (d1) and the structural unit (d2) are introduced. The total amount of the monomer component for introducing the structural unit (d1) and the monomer component for introducing the structural unit (d2) with respect to the total amount of the monomer components and other monomer components used as necessary It corresponds to the ratio.

  The weight average molecular weight of the component (D) is 20,000 to 500,000. When the mass average molecular weight of component (D) is within this range, the strength (breaking elongation) and electrical insulation properties (dielectric constant) of the cured product of the positive photosensitive resin composition should be good. In addition, the resolution (patterning characteristics) of the positive photosensitive resin composition can be improved. The mass average molecular weight of the component (D) is preferably 50,000 to 350,000, and more preferably 80,000 to 250,000.

  It is preferable that the glass transition temperature (Tg) of (D) component is -60-25 degreeC. When the glass transition temperature of the component (D) is within this range, the elongation at break (strength) of the cured product of the positive photosensitive resin composition can be improved. By the way, the range of the above Tg is a considerably low numerical value as compared with a general resin. The reason why the component (D) of the present invention exhibits such a low Tg is presumed to be because the component (D) contains the structural unit (d1).

The content of component (D) is preferably 10 to 30 parts by mass and more preferably 12 to 20 parts by mass with respect to 100 parts by mass of component (A). (D) By making content of a component into the said range, the intensity | strength (breaking elongation) and electrical insulation characteristic (dielectric constant) of the hardened | cured material of positive type photosensitive resin composition can be made favorable. The resolution (patterning characteristics) of the positive photosensitive composition can also be made favorable.
Further, the content of the component (D) is preferably 10 to 30 parts by mass, and 12 to 20 parts by mass when the total of the component (A) and the component (D) is 100 parts by mass. Is preferred. Within the above range, the effects of the present invention are excellent, and the chemical resistance and resolution are also excellent, which is preferable.

  In producing the component (D), as described above, in addition to the method of using the monomer as the structural unit (d1) and the monomer as the structural unit (d2) as a copolymer, for example, the structural unit A method of converting a part of the structural unit (d2) of the polymer into a structural unit (d1) by reacting a polymer containing (d2) with an alcohol such as 1-ethyl-1-cyclohexanol. It may be adopted. On the contrary, for the polymer containing the structural unit (d1), a method of converting a part of the structural unit (d1) of the polymer into the structural unit (d2) by hydrolysis is adopted. Also good.

[(S) solvent]
The solvent (hereinafter also referred to as “(S) component”) is not particularly limited, and a solvent widely used in this field can be used. For example, ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate and ethylene glycol monoethyl ether acetate; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether and propylene glycol monobutyl ether Alkyl ethers; propylene glycol dialkyl ethers such as propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether, propylene glycol dibutyl ether; propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, Propylene glycol monoalkyl ether acetates such as pyrene glycol monopropyl ether acetate and propylene glycol monobutyl ether acetate; cellosolves such as ethyl cellosolve and butyl cellosolve; carbitols such as butyl carbitol; methyl lactate, ethyl lactate, n-propyl lactate Lactic acid esters such as isopropyl lactate; ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, n-amyl acetate, isoamyl acetate, isopropyl propionate, n-butyl propionate, isobutyl propionate, etc. Aliphatic carboxylic acid esters of methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate Other esters such as methyl pyruvate and ethyl pyruvate; aromatic hydrocarbons such as toluene and xylene; ketones such as 2-heptanone, 3-heptanone, 4-heptanone and cyclohexanone; N-dimethylformamide, N- Examples include amides such as methylacetamide, N, N-dimethylacetamide, and N-methylpyrrolidone; and lactones such as γ-butyrolactone. These solvents may be used alone or in combination of two or more.

  The content of the component (S) is not particularly limited, but in general, the amount in which the solid content concentration of the positive photosensitive resin composition is 10 to 60% by mass is preferable, and the amount to be 20 to 50% by mass is more preferable. preferable.

[(E) Nitrogen-containing basic compound]
The positive photosensitive resin composition according to this embodiment preferably further contains (E) a nitrogen-containing basic compound (hereinafter also referred to as “component (E)”). The component (E) catalyzes that the component (A) is crosslinked by the component (C) when the photosensitive resin composition after development is heated and cured. As a result, the heating temperature during the thermosetting treatment can be lowered, and the obtained cured product has the same elongation at break as the cured product obtained by thermosetting at a high temperature, and also has chemical resistance. Can be improved. Although it is not particularly limited, specifically, by adding the component (E) to the positive photosensitive resin composition, the heating temperature of the thermosetting treatment of the positive photosensitive resin composition is reduced to about 180 ° C. or less. It becomes possible to make it. Lowering the heating temperature of the thermosetting treatment is preferable because the dielectric constant and the limit resolving power are improved.

  (E) A component is a compound containing a basic nitrogen atom. Examples of the component (E) include nitrogen-containing organic compounds, which are not particularly limited, but include hexylamine, heptylamine, octylamine, nonylamine, decylamine, aniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, ethylenediamine, tetramethylenediamine, hexamethylenediamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tripentylamine, Trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine Silamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine , Ethyldidecylamine, dicyclohexylmethylamine, triethanolamine, triisopropanolamine and other aliphatic amine compounds; aniline, N-methylaniline, diphenylamine, N, N-dimethylaniline, 2,6-isopropylaniline and other aromatics Amine compounds; piperidine, imidazole, piperidine, pyridine, 4-methylpyridine, 2-hydroxymethylpyridine, 2- (2-hydroxyethyl) pyridine, 2- 3-hydroxypropyl) pyridine, 4-methyl imidazole, heterocyclic compounds, and the like to the nitrogen of the bipyridine and heteroatoms. Among these, considering the storage stability of the positive photosensitive resin composition, a heterocyclic compound having nitrogen as a hetero atom is preferable, and 2-hydroxymethylpyridine, 2- (2-hydroxyethyl) pyridine or 2- ( 3-hydroxypropyl) pyridine is more preferred. These nitrogen-containing organic compounds may be used alone or in combination of two or more.

  The content of the component (E) is preferably 0.1 to 10 parts by mass and more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the component (A). (E) By making content of a component into the said range, the heating temperature in the thermosetting process of positive photosensitive resin composition can be reduced favorably, and the storage stability of positive photosensitive resin composition Can be good.

[Other ingredients]
The positive photosensitive resin composition of this embodiment may contain other monomers, additional resins, acid generators, plasticizers, stabilizers, colorants, surfactants, and the like as desired.
For example, by adding a (meth) acrylic monomer to the positive photosensitive resin composition, the residual stress in the cured product after thermosetting is reduced, and the occurrence of cracks in the cured product can be suppressed, or a substrate such as a wafer can be formed. This is preferable because warping and bending of the substrate and the cured product when the substrate is thinned can be suppressed.
Also, by adding an epoxy resin to the positive photosensitive resin composition, since the residual stress in the cured product after heat curing is reduced, the same effect as when the (meth) acrylic monomer is added can be obtained. Therefore, it is preferable. In addition, the effect of improving heat resistance and chemical resistance is also obtained, which is preferable.

  Next, the hardened | cured material which hardened the positive photosensitive resin composition of this embodiment is demonstrated. This cured product can be used as a permanent insulating film, and can be suitably used as, for example, an interlayer insulating film or a surface protective film of a semiconductor element.

  In order to form such a cured product, first, the positive photosensitive resin composition of the present embodiment is applied to a substrate such as a silicon wafer and dried to form a coating film. Examples of the coating method include a dipping method, a spray method, a bar coating method, a roll coating method, a spin coating method, and a curtain coating method. The thickness of the coating film can be appropriately controlled by adjusting the coating method and the solid content concentration and viscosity of the positive photosensitive resin composition.

Next, the coating film is exposed through a desired mask pattern. Examples of the radiation used for the exposure include ultraviolet rays, electron beams, and laser beams emitted from a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, a g-line stepper, an i-line stepper, and the like. The amount of exposure is about 500 to 1500 mJ / cm ² at a film thickness of 10 μm, although it varies depending on the light source used and the film thickness of the coating film.

  Next, the coating film is developed with an alkaline developer, and the exposed portion is dissolved and removed to obtain a desired resin pattern. Examples of the developing method include shower developing method, spray developing method, immersion developing method, paddle developing method and the like. Examples of the alkaline developer include an alkaline aqueous solution in which an alkaline compound such as sodium hydroxide, potassium hydroxide, aqueous ammonia, tetramethylammonium hydroxide, choline, etc. is dissolved in water so that the concentration is about 1 to 10% by mass. Is mentioned.

  Then, a cured film can be obtained by heating (thermosetting treatment) the obtained resin pattern. Although it does not specifically limit as heating conditions, It is about 30 minutes-about 10 hours at the temperature of 100-250 degreeC. At this time, heating may be performed in two stages. For example, the first stage may be heated at a temperature of 50 to 100 ° C. for 10 minutes to 2 hours, and the second stage may be heated at a temperature of 100 to 250 ° C. for 20 minutes to 3 hours. In addition, as already stated, when (E) component is contained in the positive photosensitive composition of this embodiment, this heating temperature can be made lower than the conventional positive photosensitive resin composition. For example, when the positive photosensitive resin composition of the present embodiment is used, the heating condition may be about 100 to 200 ° C., and in the case of two-stage heating, the first stage is 50 to 100 ° C., second The step may be about 100-200 ° C. The heating conditions may be set as appropriate by observing the state of the cured product to be produced.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the scope of the present invention is not limited to the following examples.

[Examples 1-14, Comparative Examples 1-11]
According to the formulations described in Tables 1 to 3 (unit is part by mass), an alkali-soluble resin having a phenolic hydroxyl group, a compound having a quinonediazide group, a crosslinking agent, an acrylic resin, a nitrogen-containing basic compound, a solvent, an acrylic monomer, and an epoxy resin Were mixed to prepare positive photosensitive resin compositions of Examples 1 to 14 and Comparative Examples 1 to 11. In addition, in Tables 1-3, it is meaning that it is not mix | blended in the case of preparation of the positive photosensitive resin composition about the component whose compounding quantity is blank. In Tables 1 to 3, for simplification, an alkali-soluble resin having a phenolic hydroxyl group is referred to as “phenol resin”, a compound having a quinonediazide group as “quinonediazide compound”, and a nitrogen-containing basic compound as “basic compound”. ". Details of each component in Tables 1 to 3 are as follows.

Phenol resin A: cresol novolak resin (mass average molecular weight 8000) obtained by addition of formalin to m-cresol and addition condensation by a conventional method
Phenol resin B: cresol novolak resin (mass) obtained by mixing m-cresol and p-cresol at m-cresol / p-cresol = 60/40 (mass ratio), adding formalin and addition-condensing by a conventional method. (Average molecular weight 20000)

Quinonediazide compound A: 2.0 mol% of hydrogen atoms of all hydroxyl groups of bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -3,4-dihydroxyphenylmethane, 1,2-naphthoquinonediazide-5 Compound substituted with sulfonyl group Quinonediazide compound B: 2.2 mol% of the total hydroxyl groups of 4,4 ′-[1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] bisphenol A compound in which the hydrogen atom is substituted with a 1,2-naphthoquinonediazide-4-sulfonyl group

  Cross-linking agent: 2,4,6-tris [bis (methoxymethylamino)]-1,3,5-triazine (manufactured by Sanwa Chemical Co., Ltd., Mw-100LM)

Acrylic resin A: A monomer mixed at a ratio of 1-ethylcyclohexyl acrylate / 2-methoxyethyl acrylate / n-butyl acrylate / acrylic acid = 44.1 / 36.8 / 12.3 / 6.8 was obtained by a conventional method. Acrylic resin obtained by radical polymerization (mass average molecular weight 100,000, Tg = −14.2 ° C.)
Acrylic resin B: A monomer mixed at a ratio of 1-ethylcyclohexyl acrylate / 2-methoxyethyl acrylate / n-butyl acrylate / acrylic acid = 44.1 / 36.8 / 12.3 / 6.8 was obtained by a conventional method. Acrylic resin obtained by radical polymerization (mass average molecular weight 220,000, Tg = −14.2 ° C.)
Acrylic resin C: Acrylic resin obtained by radical polymerization of monomers mixed in a ratio of 1-ethylcyclohexyl acrylate / 2-methoxyethyl acrylate / methacrylic acid = 43.5 / 48.3 / 8.2 by a conventional method ( (Mass average molecular weight 200000, Tg = -11.4 ° C.)

Acrylic resin D: A monomer mixed in a ratio of 1-ethylcyclohexyl acrylate / 2-methoxyethyl acrylate / methoxytriethylene glycol acrylate / acrylic acid = 44.1 / 36.8 / 12.3 / 6.8 Acrylic resin obtained by radical polymerization (mass average molecular weight 220,000, Tg = −14.4 ° C.)
Acrylic resin E: A monomer mixed in a ratio of 2-ethylcyclohexyl acrylate / 2-methoxyethyl acrylate / n-butyl acrylate / acrylic acid = 44.1 / 36.8 / 12.3 / 6.8 was prepared by a conventional method. Acrylic resin obtained by radical polymerization (mass average molecular weight 220,000, Tg = −14.2 ° C.)
Acrylic resin F: A monomer mixed at a ratio of 1-ethylcyclohexyl acrylate / 2-methoxyethyl acrylate / n-butyl acrylate / acrylic acid = 44.1 / 36.8 / 12.3 / 6.8 is obtained by a conventional method. Acrylic resin obtained by radical polymerization (mass average molecular weight 20000, Tg = −14.2 ° C.)

Acrylic resin G: Monomer mixed at a ratio of 1-ethylcyclohexyl acrylate / 2-methoxyethyl acrylate / methoxytriethylene glycol acrylate / acrylic acid = 44.1 / 36.8 / 12.3 / 6.8 Acrylic resin obtained by radical polymerization (mass average molecular weight 8000, Tg = −14.4 ° C.)
Acrylic resin H: A monomer mixed at a ratio of styrene / 2-methoxyethyl acrylate / methoxytriethylene glycol acrylate / acrylic acid = 44.1 / 36.8 / 12.3 / 6.8 was radically polymerized by a conventional method. Acrylic resin obtained (mass average molecular weight 220,000, Tg = 6.6 ° C.)
Acrylic resin I: benzyl methacrylate / 2-methoxyethyl acrylate / methoxytriethylene glycol acrylate / acrylic acid = 44.1 / 36.8 / 12.3 / 6.8 Acrylic resin obtained (mass average molecular weight 220,000, Tg = −5.8 ° C.)

Acrylic resin J: A monomer mixed in a ratio of dicyclopentanyl methacrylate / 2-hydroxyethyl methacrylate / 2-methoxyethyl acrylate / n-butyl acrylate / methacrylic acid = 65/7/4/4/20 by a conventional method Acrylic resin obtained by radical polymerization (mass average molecular weight 20000, Tg = 129.8 ° C.)
Acrylic resin K: radical polymerization of monomers mixed at a ratio of adamantyl methacrylate / 2-hydroxyethyl methacrylate / 2-methoxyethyl acrylate / n-butyl acrylate / methacrylic acid = 65/7/4/4/20 by a conventional method Acrylic resin obtained (mass average molecular weight 30000, Tg = 135 ° C.)
Acrylic resin L: Acrylic resin obtained by radical polymerization of monomers mixed at a ratio of 1-ethylcyclohexyl acrylate / 2-methoxyethyl acrylate / n-butyl acrylate = 44.1 / 36.8 / 19.1 by a conventional method Resin (mass average molecular weight 220,000, Tg = -22.0 ° C.)

Basic compound A: 2-hydroxymethylpyridine Basic compound B: 2- (2-hydroxyethyl) pyridine Basic compound C: 2- (3-hydroxypropyl) pyridine

Acrylic monomer A: Dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., DPHA)
Acrylic monomer B: pentaerythritol tetraacrylate (Toagosei Co., Ltd., Aronix M-450)
Acrylic monomer C: ethylene oxide-modified trimethylolpropane triacrylate (Aronix M-350, manufactured by Toagosei Co., Ltd.)
Epoxy resin: tetrafunctional cyclic epoxy resin (manufactured by Daicel Chemical Industries, Epolide GT-401)
Solvent: Propylene glycol monomethyl ether acetate

[Evaluation of strength of cured product]
As an evaluation of the strength of the cured product, the elongation at break of the cured product was measured.
For each of the positive photosensitive resin compositions of Examples 1 to 14 and Comparative Examples 1 to 11, the positive photosensitive resin composition was applied to the surface of a 6-inch silicon wafer by spin coating, and the coating was performed at 120 ° C. for 3 minutes. It dried and the coating film with a film thickness of 25 micrometers was obtained. Next, this coating film was heated at 180 ° C. for 2 hours to obtain a cured product having a thickness of 20 μm. The obtained cured product was cut into a size of 8 mm × 5 cm to obtain a strip-shaped sample. The breaking elongation (%) of this sample was evaluated using RTC-1210A TENDILON (manufactured by ORIENTEC). Specifically, an upward load is applied to the sample at a speed of 5 mm / min until the sample is cut by the weight, and (the length when the sample is cut−the length of the original sample) / (the original sample The elongation at break (%) was calculated by the formula of (length) × 100. The results are shown in Tables 1-3.

[Measurement of dielectric constant]
As an evaluation of the electrical insulation characteristics of the cured product, the dielectric constant of the cured product was measured.
For each of the positive photosensitive resin compositions of Examples 1 to 14 and Comparative Examples 1 to 11, the positive photosensitive resin composition was applied to the surface of a 6-inch silicon wafer by spin coating, and the coating was performed at 120 ° C. for 3 minutes. It dried and the coating film with a film thickness of 6 micrometers was obtained. Next, this coating film was heated at 180 ° C. for 2 hours to obtain a cured product having a thickness of 5 μm. About this hardened | cured material, the relative dielectric constant with respect to the vacuum of a film thickness direction was measured using the dielectric constant measuring apparatus SSM495 CVSystem (made by Solid State Measurement). The results are shown in Tables 1-3.

[Evaluation of resolution]
For each of the positive photosensitive resin compositions of Examples 1 to 14 and Comparative Examples 1 to 11, the positive photosensitive resin composition was applied to the surface of a 6-inch silicon wafer by spin coating, and the coating was performed at 120 ° C. for 3 minutes. It dried and the coating film with a film thickness of 6 micrometers was obtained. Using a Prisma ghi stepper device manufactured by Ultratech, the coating film is 1000 mJ / cm ² through a photomask on which a test pattern in which a circular pattern having a size of 1 μm is mixed is recorded from 1 to 20 μm. Exposure was performed. The exposed coating film is developed with a developer (NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.) to form a resin pattern, and the obtained resin pattern is further heated at 180 ° C. for 2 hours (however, Example 12 is 200). C. for 2 hours to obtain a cured product. The cross section of the obtained cured product was observed with an SEM, and the limit resolving power (unit: μm) was evaluated. The results are shown in Tables 1-3.

As understood from Tables 1 to 3, it includes the structural unit (d1) represented by the general formula (1) and the structural unit (d2) derived from unsaturated carboxylic acid, and has a mass average molecular weight of 20,000 to In the positive photosensitive resin compositions of Examples 1 to 14 including an acrylic resin (acrylic resin A to acrylic resin F) of 500,000, the resolution (limit resolution) of the positive photosensitive resin composition, and its The electrical insulation properties (dielectric constant) and strength (breaking elongation) of the cured product are improved in a well-balanced manner.
On the other hand, Comparative Examples 7 to 10 in which the acrylic resin does not contain the structural unit (d1) represented by the general formula (1), Comparative Example 6 in which the mass average molecular weight of the acrylic resin is less than 20,000, and the acrylic resin In the positive photosensitive resin composition of Comparative Example 11 that does not contain a structural unit (d1) derived from an unsaturated carboxylic acid, the resolution (limit resolution) of the positive photosensitive resin composition and its cured product The results were inferior in all or at least one of the electrical insulation characteristics (dielectric constant) and strength (breaking elongation).
In addition, by comparing Examples 9, 11 and 12, the inclusion of the component (E) improves the dielectric constant and the critical resolving power while maintaining good elongation at break of the positive photosensitive resin composition. It was confirmed that That is, the cured product of the positive photosensitive resin composition of Example 11 obtained by removing the component (E) from the positive photosensitive resin composition of Example 9 was cured of the positive photosensitive resin composition of Example 9. In order for the elongation at break to be smaller than that of the product and to be equivalent to the cured product of the positive photosensitive resin composition of Example 9, the thermosetting temperature needs to be 200 ° C., which is 20 ° C. higher than 180 ° C. It is understood that (see Example 12). However, in this case, as shown in Example 12, even when the elongation at break can be made equivalent to that in Example 9, the dielectric constant and the limit resolving power are lowered, and these characteristics are good. It is understood that it cannot be maintained.

Claims (3)

(A) an alkali-soluble resin having a phenolic hydroxyl group, (B) a compound having a quinonediazide group, (C) a compound having at least two alkyl etherified amino groups in the molecule, (D) the following general formula (1) A positive type containing an acrylic resin having a mass average molecular weight of 20,000 to 500,000, and a (S) solvent, comprising a structural unit (d1) represented by formula (1) and a structural unit (d2) derived from an unsaturated carboxylic acid Photosensitive resin composition.

(In the general formula (1), R ¹ represents a hydrogen atom or an alkyl group, R ² independently represents a hydrocarbon group, and p represents 0 to 3).   The positive photosensitive resin composition according to claim 1, further comprising (E) a nitrogen-containing basic compound. The positive photosensitive resin composition according to claim 1 or 2, wherein the (D) acrylic resin contains a structural unit represented by the following general formula (2) as the structural unit (d1).

(In the general formula (2), R ¹ and R ² are the same as those in the general formula (1).)