JP5181444B2 - Crosslinkable fluorine-containing aromatic prepolymer and cured product thereof - Google Patents

Description

  The present invention relates to a crosslinkable fluorine-containing aromatic prepolymer and a cured product thereof.

  With the miniaturization and high integration of electronic devices and multilayer wiring boards, an insulating film having a lower relative dielectric constant is required. In recent years, it has been proposed to apply organic materials as these insulating films because the manufacturing process of electronic devices and the like can be simplified. In particular, aromatic resin compositions having both good heat resistance and low dielectric constant represented by a high glass transition temperature (Tg) have been proposed (see, for example, Patent Documents 1 to 3).

JP-A-10-247646 International Publication No. 03/008483 Pamphlet JP 2005-105115 A

  However, in the technique of Patent Document 1, the heat resistance temperature of the cured product is low and the chemical resistance is insufficient. On the other hand, the techniques of Patent Documents 2 and 3 have a problem that the heating temperature (curing temperature) for causing a crosslinking reaction to obtain a cured product is high. That is, heating at a certain temperature or higher is necessary to obtain a cured product having sufficient physical properties.

  An object of the present invention is to obtain a cured product having sufficiently balanced physical properties even when the curing temperature is low. That is, an object of the present invention is to obtain a composition capable of obtaining a cured product having practically sufficient heat resistance and sufficiently low relative dielectric constant even when heating during production is performed at a low temperature.

  The present invention provides the following crosslinkable fluorine-containing aromatic prepolymer in order to solve the above problems. The crosslinkable fluorine-containing aromatic prepolymer of the present invention has the following formula (1)

[Wherein, R ¹ represents a monovalent organic group having a crosslinkable functional group, and R ² represents a haloalkyl group having 8 or less carbon atoms. And a hydrocarbon aromatic compound (A) represented by the following formula (2):

[Wherein, n is an integer of 0 to 3; a and b each independently represents an integer of 0 to 3, and Rf ¹ and Rf ² may be the same or different and each may contain 8 or less carbon atoms. F represents a fluorine alkyl group, and F in the aromatic ring represents that all hydrogen atoms in the aromatic ring are substituted with fluorine atoms. And a compound having three or more phenolic hydroxyl groups (C) in the presence of a dehydrohalogenating agent to obtain a crosslinkable functional group and an ether. It has a bond and has a number average molecular weight of 1,000 to 500,000.

Here, R ² is —R ³ —X [wherein R ³ represents an alkylene group having 8 or less carbon atoms, and X represents a chlorine atom or a bromine atom. It is preferable that it is a haloalkyl group represented by this. Further, R ³ is preferably an alkylene group having 4 or less carbon atoms. R ¹ is preferably a group selected from the group consisting of a vinyl group, a methacryloyl group, a methacryloyloxy group, an acryloyl group, an acryloyloxy group, and an ethynyl group.
The hydrocarbon aromatic compound (A) is preferably a compound selected from the group consisting of chloromethylstyrene, chloroethylstyrene, chloropropylstyrene, and bromomethylstyrene. The fluorine-containing aromatic compound (B) is perfluorobenzene, perfluorotoluene, perfluoroxylene, perfluorobiphenyl, perfluoroterphenyl, perfluoro (1,3,5-triphenylbenzene), and perfluoro (1,2,4-triphenyl). It is preferably a compound selected from the group consisting of (phenylbenzene). The compound (C) having three or more phenolic hydroxyl groups is trihydroxybenzene, trihydroxybiphenyl, trihydroxynaphthalene, 1,1,1-tris (4-hydroxyphenyl) ethane, tris (4-hydroxyphenyl) benzene. And a compound selected from the group consisting of tetrahydroxybenzene, tetrahydroxybiphenyl, tetrahydroxybinaphthyl, and tetrahydroxyspiroindane.

Further, the present invention provides a cured product formed by curing the crosslinkable fluorine-containing aromatic prepolymer, a method for producing a cured product, wherein the crosslinkable fluorine-containing aromatic prepolymer is cured at 40 to 250 ° C., Provided are a coating composition containing a crosslinkable fluorine-containing aromatic prepolymer and a solvent, and an electronic component, electrical component or optical component having the cured product.

  The crosslinkable fluorine-containing aromatic prepolymer of the present invention (hereinafter sometimes simply referred to as prepolymer) can be cured at a low temperature. Therefore, the process temperature at the time of producing electronic devices such as semiconductor elements can be lowered. Thereby, the manufacturing process of the element can be simplified, and the reliability of the element can be improved by reducing the thermal load applied to the element.

  If the prepolymer of this invention is used, the hardened | cured material which satisfies a low dielectric constant and high heat resistance simultaneously with sufficient balance will be obtained. In addition, since the prepolymer of the present invention can form a cured film having excellent flexibility, a film resistant to external force such as bending can be obtained. A thick film can also be easily formed.

[Prepolymer]
The prepolymer of the present invention has the following formula (1)

[Wherein, R ¹ represents a monovalent organic group having a crosslinkable functional group, and R ² represents a haloalkyl group having 8 or less carbon atoms. And a hydrocarbon aromatic compound (A) represented by the following formula (2):

[Wherein, n is an integer of 0 to 3; a and b each independently represents an integer of 0 to 3, and Rf ¹ and Rf ² may be the same or different and each may contain 8 or less carbon atoms. F represents a fluorine alkyl group, and F in the aromatic ring represents that all hydrogen atoms in the aromatic ring are substituted with fluorine atoms. And a compound having three or more phenolic hydroxyl groups (C) in the presence of a dehydrohalogenating agent to obtain a crosslinkable functional group and an ether. It has a bond and has a number average molecular weight of 1,000 to 500,000 (1 × 10 ^{3 to} 5 × 10 ⁵ ).

  The prepolymer of the present invention is produced using the compound (C) having 3 or more phenolic hydroxyl groups and has a crosslinkable functional group, thereby satisfying low dielectric constant, low water absorption and high heat resistance at the same time. A cured product (fluorinated aromatic polymer) is obtained. That is, by using the compound (C) having three or more phenolic hydroxyl groups, a branched structure is introduced into the polymer chain, and the molecular structure is made three-dimensional, thereby increasing the free volume of the polymer and reducing the density. That is, a low dielectric constant is achieved. In general, a linear polymer having an aromatic ring tends to cause molecular orientation due to stacking of aromatic rings, but the cured product of the present invention can suppress molecular orientation by introducing a branched structure. Birefringence is reduced.

  By having a crosslinkable functional group, in the obtained cured product, crosslinking or chain extension reaction between prepolymer molecules can proceed, and as a result, heat resistance is greatly improved. At the same time, it has the effect of improving the solvent resistance and chemical resistance of the cured product.

  Furthermore, by using the fluorine-containing aromatic compound (B) represented by the formula (2), a cured product having good flexibility can be obtained. Compared to fluorine-containing aromatic polymers produced from fluorine-containing aromatic compounds that themselves have a branched structure, the density of ether bonds can be increased, and the flexibility of the main chain is improved, resulting in flexibility. A good cured product is obtained. Good flexibility is particularly advantageous when the cured product is in the form of a cured film.

[Hydrocarbon aromatic compound (A)]
The hydrocarbon aromatic compound (A) according to the present invention has the following formula (1):

[Wherein, R ¹ represents a monovalent organic group having a crosslinkable functional group, and R ² represents a haloalkyl group having 8 or less carbon atoms. ].

  The crosslinkable functional group does not substantially react during the production of the prepolymer, and reacts by applying external energy at the time of producing a cured product such as a film, a film, or a molded product, or at any time after the production. , Reactive functional groups that cause cross-linking or chain extension between prepolymer molecules.

  As the external energy, heat, light, an electron beam, etc., and a combination thereof are preferable because of excellent applicability in the manufacturing and / or mounting process of an electronic device, a multilayer wiring board or an optical transmission body. When heat is used as external energy, a reactive functional group that reacts at a temperature of 40 to 250 ° C. is preferable. The preferred temperature range is more preferably from 60 to 200 ° C, particularly preferably from 70 to 200 ° C. If it is too low, it is difficult to ensure the stability of the prepolymer or the coating composition containing the prepolymer during storage. On the other hand, if it is too high, thermal decomposition of the prepolymer itself occurs during the reaction. When light is used as the external energy, it is also preferable to add a photo radical generator, a photo acid generator, a sensitizer, or the like to the prepolymer or a coating composition containing the prepolymer described later. In addition, since the crosslinkable functional group containing no polar group does not increase the relative dielectric constant of the cured film, the crosslinkable functional group containing no polar group is particularly used when the prepolymer of the present invention is applied to the production of an insulating film. Is preferably used.

  Specific examples of the crosslinkable functional group include a vinyl group, an allyl group, a methacryloyl group, a methacryloyloxy group (hereinafter collectively referred to as a methacryloyl (oxy) group, and other groups are the same), an acryloyl (oxy) group. , Vinyloxy group, trifluorovinyl (oxy) group, ethynyl group, 1-oxocyclopenta-2,5-dien-3-yl group, cyano group, alkoxysilyl group, diarylhydroxymethyl group, hydroxyfluorenyl group, etc. Is mentioned. A vinyl group, a methacryloyl (oxy) group, an acryloyl (oxy) group, and an ethynyl group are preferable because of high reactivity and high crosslink density. A vinyl group and an ethynyl group are the most preferable because they have high reactivity and the resulting cured product has good heat resistance.

R ¹ is a monovalent organic group having these crosslinkable functional groups. That is, a single bond or a divalent organic group (for example, an alkylene group or an arylene group) may be present between the functional group and the aromatic ring. In the present invention, R ¹ is preferably a group selected from the group consisting of a vinyl group, a methacryloyl (oxy) group, an acryloyl (oxy) group, and an ethynyl group.

  The content of the crosslinkable functional group in the prepolymer of the present invention is preferably from 0.1 to 4 mmol, more preferably from 0.2 to 3 mmol, based on 1 g of the prepolymer. When this range is exceeded, the brittleness of the cured product increases and the relative dielectric constant may increase. Moreover, when less than this range, the heat resistance and solvent resistance of hardened | cured material may fall.

R ² is a haloalkyl group having 8 or less carbon atoms, and is preferably a haloalkyl group represented by —R ³ —X. However, R ³ represents an alkylene group having 8 or less carbon atoms, preferably 4 or less carbon atoms, and X represents a chlorine atom or a bromine atom.

  As such a hydrocarbon aromatic compound (A), styrenes can be preferably exemplified. That is, chloromethyl styrene, chloroethyl styrene, chloropropyl styrene, bromomethyl styrene and the like are preferable, and chloromethyl styrene can be particularly preferably exemplified. These are preferable in that the reactivity of the crosslinkable functional group is high and the curing temperature of the prepolymer can be lowered.

[Fluorine-containing aromatic compound (B)]
In the present invention, the fluorine-containing aromatic compound (B) is a fluorine-containing aromatic compound represented by the formula (2). In the formula (2), Rf ¹ and Rf ² are fluorine-containing alkyl groups having 8 or less carbon atoms. From the viewpoint of heat resistance, a perfluoroalkyl group is preferred. Specific examples include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluorohexyl group, and a perfluorooctyl group.

When the amount of Rf ¹ and Rf ² increases, the production of the fluorinated aromatic compound (B) becomes difficult. Therefore, the number of Rf ¹ and Rf ² (a and b) is preferably 0 to 2, and 0 is the most. preferable.

  As the fluorine-containing aromatic compound (B), (when n = 0) perfluorobenzene, perfluorotoluene, perfluoroxylene; (when n = 1) perfluorobiphenyl; (when n = 2) perfluoroterphenyl; (n = 3) Perfluoro (1,3,5-triphenylbenzene) and perfluoro (1,2,4-triphenylbenzene) are preferable, and perfluorobenzene and perfluorobiphenyl are particularly preferable. These may be used alone or in combination of two or more. Perfluorobiphenyl is most preferable as the fluorine-containing aromatic compound (B) in that the obtained cured product is excellent in the balance between the dielectric constant and heat resistance and the flexibility of the cured product is increased.

[Compound (C) having 3 or more phenolic hydroxyl groups]
In the present invention, polyfunctional phenols are preferred as the compound (C) having three or more phenolic hydroxyl groups. Although the number of phenolic hydroxyl groups in the compound (C) is 3 or more, it is practically preferably 3-6, and particularly preferably 3-4. Specific examples include trihydroxybenzene, trihydroxybiphenyl, trihydroxynaphthalene, 1,1,1-tris (4-hydroxyphenyl) ethane, tris (4-hydroxyphenyl) benzene, tetrahydroxybenzene, tetrahydroxybiphenyl, tetra Examples thereof include hydroxybinaphthyl and tetrahydroxyspiroindanes. Since the flexibility of the obtained cured film becomes high, the compound (C) is preferably a compound having three phenolic hydroxyl groups. Among them, trihydroxybenzene and 1,1,1-tris (4-hydroxyphenyl) ethane are particularly preferable because the resulting cured product has a low dielectric constant.

[Prepolymer production method]
The prepolymer of the present invention comprises a dehydrohalogenating agent comprising the hydrocarbon aromatic compound (A), the fluorine-containing aromatic compound (B), and the compound (C) having three or more phenolic hydroxyl groups. Obtained by a condensation reaction in the presence.

  In the condensation reaction, the hydrocarbon aromatic compound (A), the fluorine-containing aromatic compound (B), and the compound (C) having three or more phenolic hydroxyl groups may be reacted at the same time. However, from the viewpoint of reaction efficiency, the hydrocarbon aromatic compound (A) and the compound (C) having three or more phenolic hydroxyl groups are reacted first, and before or after the reaction is completed, the fluorine-containing aromatic compound ( B) is preferably added and reacted. For example, a hydrocarbon aromatic compound (A) and a compound (C) having 3 or more phenolic hydroxyl groups are reacted in the presence of a dehydrohalogenating agent, and the fluorine-containing aromatic compound (B) is subsequently added to the reaction system. A method of adding and reacting can be suitably exemplified.

  In the condensation reaction, a phenoxy group derived from a phenolic hydroxyl group attacks a carbon atom to which a halogen atom in the haloalkyl group of the hydrocarbon aromatic compound (A) is bonded, and then a reaction mechanism in which the halogen atom is eliminated. An ether bond is formed. Further, similarly, the phenoxy group derived from the phenolic hydroxyl group attacks the carbon atom to which the fluorine atom of the fluorine-containing aromatic compound (B) is bonded, and then the ether bond is similarly formed by the reaction mechanism in which the fluorine atom is eliminated. Generate. Depending on the positional relationship of the aromatic rings in the condensation reaction, a dioxin skeleton may be generated.

  The dehydrohalogenating agent is preferably a basic compound, particularly preferably an alkali metal carbonate, bicarbonate or hydroxide. Specific examples include sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium hydroxide, potassium hydroxide and the like.

  The amount of the dehydrohalogenating agent used is required to be 1 or more times in terms of the molar ratio with respect to the number of moles of the phenolic hydroxyl group of the compound (C), and preferably 1.1 to 3 times.

  In the production method, the condensation reaction is preferably performed in a polar solvent. As the polar solvent, a solvent containing an aprotic polar solvent such as N, N-dimethylacetamide, N, N-dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane and the like is preferable. The polar solvent may contain toluene, xylene, benzene, tetrahydrofuran, benzotrifluoride, xylene hexafluoride, and the like as long as the solubility of the prepolymer to be produced is not lowered and the condensation reaction is not adversely affected. . By containing these, the polarity (dielectric constant) of the solvent changes, and the reaction rate can be controlled.

The condensation reaction conditions are preferably 10 to 200 ° C. and 1 to 80 hours. More preferably 2
It is 2 to 60 hours at 0 to 180 ° C, and most preferably 3 to 24 hours at 50 to 160 ° C.

The number average molecular weight of the prepolymer of the present invention is 1,000 to 500,000 (1 × 10 ^{3 to} 5 × 10 ⁵ ). More preferably, it is the range of 1,500-100,000. When in this range, the coating properties of the composition containing the prepolymer described later are good, and the resulting cured film has good heat resistance, mechanical properties, solvent resistance, and the like. In the case of insulating films for electronic devices, when a property of sufficiently penetrating between minute spaces of the base and smoothing the surface (so-called embedded flatness) is required, the number average molecular weight of the prepolymer is 1,500. A range of ˜50,000 is most preferred.

  The number average molecular weight of the prepolymer can be controlled by changing the charging ratio of the total of the hydrocarbon aromatic compound (A) and the fluorine-containing aromatic compound (B) and the compound (C). Here, it is preferable that no hydroxyl group remains in the prepolymer since the relative dielectric constant of the cured product is lowered. In the condensation reaction in the present invention, the fluorine-containing aromatic compound (B) usually serves as a bifunctional compound. Therefore, molecular weight control is such that the total number of moles of hydroxyl groups in compound (C) does not exceed the sum of the number of moles of fluorine-containing aromatic compound (B) and the number of moles of hydrocarbon aromatic compound (A). It is preferable to adjust within the range.

  Specifically, the amount of the compound (C) used is preferably 0.5 to 2 times, more preferably 0.6 to 1.5 times in terms of a molar ratio to the fluorine-containing aromatic compound (B). The amount of the hydrocarbon aromatic compound (A) used is preferably 0.1 to 2 times, more preferably 0.2 to 1.5 times in terms of molar ratio to the fluorine-containing aromatic compound (B). Each value within this range is preferable because the obtained prepolymer has both a low dielectric constant and high heat resistance.

  In the present invention, when the heat resistance of the cured product of the prepolymer is insufficient or the film or film made of the cured product is brittle, the heat resistance of the cured product is improved and the flexibility is improved. For this purpose, a cocondensation component can be added during the preparation of the prepolymer.

  As a co-condensation component, a compound (Z) having two phenolic hydroxyl groups for improving the flexibility of the cured film, and an aromatic compound (Y) having a crosslinkable functional group for improving the heat resistance of the cured film. ) (The hydrocarbon aromatic compound (A) is not included).

  Examples of the compound (Z) having two phenolic hydroxyl groups include dihydroxybenzene, dihydroxybiphenyl, dihydroxyterphenyl, dihydroxynaphthalene, dihydroxyanthracene, dihydroxyphenanthracene, dihydroxy-9,9-diphenylfluorene, dihydroxydibenzofuran, dihydroxydiphenyl ether. And bifunctional phenols such as dihydroxydiphenyl thioether, dihydroxybenzophenone, dihydroxy-2,2-diphenylpropane, dihydroxy-2,2-diphenylhexafluoropropane, and dihydroxybinaphthyl. These may be used alone or in combination of two or more.

  As the aromatic compound (Y) having a crosslinkable functional group, a compound (Y-1) having a crosslinkable functional group and a phenolic hydroxyl group, and a compound having a crosslinkable functional group and a fluorine atom-substituted aromatic ring (Y -2).

  Examples of the compound (Y-1) include 4-hydroxystyrene, 3-ethynylphenol, 4-phenylethynylphenol, 4- (4-fluorophenyl) ethynylphenol, 2,2′-bis (phenylethynyl) -5,5. Examples include '-dihydroxybiphenyl, 2,2'-bis (phenylethynyl) -4,4'-dihydroxybiphenyl, 4,4'-dihydroxytolane, 3,3'-dihydroxytolane and the like.

  As the compound (Y-2), pentafluorostyrene, pentafluorobenzyl acrylate, pentafluorobenzyl methacrylate, pentafluorophenyl acrylate, pentafluorophenyl methacrylate, perfluorostyrene, pentafluorophenyl trifluorovinyl ether, 3- (pentafluorophenyl) ) Pentafluoropropene-1, pentafluorobenzonitrile, pentafluorophenylacetylene, nonafluorobiphenylacetylene, phenylethynylpentafluorobenzene, phenylethynylnonafluorobiphenyl, decafluorotolane and the like.

  The prepolymer of the present invention is purified by a method such as neutralization, reprecipitation, extraction or filtration after the condensation reaction or solution. The purification is preferably performed in a state where a polar solvent that is preferably used during production is present or in a state where it is dissolved or dispersed in a solvent described later, because it is more efficient. In applications as insulating films for electronic devices and insulating films for multilayer wiring boards, metals such as potassium and sodium, which are condensation reaction catalysts, and free halogen atoms can cause transistor malfunction and wiring corrosion. Therefore, it is preferable to purify it sufficiently.

[Additives used in combination with prepolymers]
In the present invention, during the crosslinking reaction for curing, various catalysts or additives can be used in combination with the prepolymer for the purpose of increasing the reaction rate or reducing reaction defects.

  When the prepolymer contains an ethynyl group as a crosslinkable functional group, the catalyst is an organic metal containing amines such as aniline, triethylamine, aminophenyltrialkoxysilane, aminopropyltrialkoxysilane, molybdenum, nickel, etc. A compound etc. can be illustrated.

  As the additive, a biscyclopentadienone derivative is preferable. An ethynyl group and a cyclopentadienone group (1-oxocyclopenta-2,5-dien-3-yl group) form an adduct by Diels-Alder reaction with heat, and then decarbonize to form an aromatic ring. Form. Therefore, when a biscyclopentadienone derivative is used, crosslinking or chain extension in which an aromatic ring is a binding site can be performed.

  Specific examples of the biscyclopentadienone derivative include 1,4-bis (1-oxo-2,4,5-triphenyl-cyclopenta-2,5-dien-3-yl) benzene, 4,4′- Bis (1-oxo-2,4,5-triphenyl-cyclopenta-2,5-dien-3-yl) biphenyl, 4,4′-bis (1-oxo-2,4,5-triphenyl-cyclopenta -2,5-dien-3-yl) 1,1'-oxybisbenzene, 4,4'-bis (1-oxo-2,4,5-triphenyl-cyclopenta-2,5-diene-3- Yl) 1,1′-thiobisbenzene, 1,4-bis (1-oxo-2,5-di- [4-fluorophenyl] -4-phenyl-cyclopenta-2,5-dien-3-yl) Benzene, 4,4′-bis (1-oxo-2,4, -Triphenyl-cyclopenta-2,5-dien-3-yl) 1,1 '-(1,2-ethanediyl) bisbenzene, 4,4'-bis (1-oxo-2,4,5-triphenyl) -Cyclopenta-2,5-dien-3-yl) 1,1 '-(1,3-propanediyl) bisbenzene and the like.

  Among these biscyclopentadienone derivatives, biscyclopentadienone derivatives having a wholly aromatic skeleton are preferable from the viewpoint of heat resistance. These may be used alone or in combination of two or more.

[Coating composition]
The present invention provides a cured product obtained by curing the prepolymer. In order to obtain this cured product, it is preferable to use a coating composition containing the prepolymer and a solvent. After this coating composition is applied to a substrate, the solvent is removed (dried) to generally obtain a prepolymer film (resin film). This prepolymer is cured to obtain a cured product (cured film). This curing is performed by applying external energy such as heat, light, and electron beam. That is, by applying external energy, a crosslinking reaction or chain extension reaction between prepolymer molecules is caused to advance the curing reaction.

  When heat is used as external energy, the final heating temperature for obtaining a cured product is preferably 40 to 250 ° C, more preferably 60 to 200 ° C. In particular, in the present invention, by using a specific hydrocarbon aromatic compound (A) as a raw material for the prepolymer, it can be cured at a low temperature without using a radical initiator or the like. 150-200 degreeC is suitable for the suitable heating temperature when not using a radical initiator.

  Further, a radical initiator or the like may be added to the coating composition in order to sufficiently cure by heat and to cure at a low temperature. The radical initiator is not particularly limited, and examples thereof include radical initiators used for ordinary radical reactions such as azo compounds, organic peroxycarbonates, and organic peroxides.

  Specific examples of the radical initiator include 4,4′-azobis (4-cyanopentanoic acid), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 1,1′-azobis ( Azo compounds such as 1-cyclohexanecarbonitrile); organic peroxycarbonates such as diisopropylperoxydicarbonate; organic peroxides such as perfluorobenzoyl peroxide, perfluorobenzoyl peroxide, perfluorononanoyl peroxide, and methyl ethyl ketone peroxide. These may be used alone or in combination of two or more.

  The amount of the coating composition in the case of using the radical initiator is preferably 0.01 to 10 parts by mass and more preferably 1 to 10 parts by mass with respect to 100 parts by mass of the prepolymer.

[solvent]
The solvent used in the coating composition of the present invention is only required to dissolve or disperse the prepolymer and, if necessary, the catalyst or additives to be added. Further, the type of solvent is not particularly limited as long as a cured film having a desired film thickness, uniformity, or embedded flatness can be obtained by a desired method. Examples include aromatic hydrocarbons, dipolar aprotic solvents, ketones, esters, ethers, and halogenated hydrocarbons. The solvent may be the same as or different from the reaction solvent used in the production of the prepolymer described above. When a different solvent is used, the prepolymer is once recovered from the reaction solution by a reprecipitation method or the like and dissolved or dispersed in a different solvent, or a known method such as an evaporation method or an ultrafiltration method is used. Thus, solvent replacement can be performed.

  Aromatic hydrocarbons include benzene, toluene, xylene, ethylbenzene, cumene, mesitylene, tetralin, methylnaphthalene and the like. Examples of the dipole aprotic solvents include N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, γ-butyrolactone, dimethyl sulfoxide and the like.

  Examples of ketones include cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, methyl amyl ketone, and the like. Examples of ethers include tetrahydrofuran, pyran, dioxane, dimethoxyethane, diethoxyethane, diphenyl ether, anisole, phenetole, diglyme, and triglyme.

  Esters include ethyl lactate, methyl benzoate, ethyl benzoate, butyl benzoate, benzyl benzoate, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether Propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate and the like.

  Examples of halogenated hydrocarbons include carbon tetrachloride, chloroform, methylene chloride, tetrachloroethylene, chlorobenzene, dichlorobenzene and the like.

[Composition of coating composition, etc.]
In the coating composition, the concentration of the prepolymer in the composition is preferably 1 to 50% by mass, and more preferably 5 to 30% by mass. In addition to the prepolymer and the solvent, this composition may contain at least one additive selected from various additives well known in the coating field such as a plasticizer and a thickener. Moreover, when forming the film | membrane or film which has a void | hole, the substance etc. which can be removed after hollow body mentioned later and thin film formation can be mix | blended suitably.

  When the prepolymer of the present invention contains a low molecular weight substance having a vapor pressure, a part of the crosslinkable functional group can be reacted in the solution in order to prevent volatilization during baking. The method is preferably heating. Heating conditions are preferably 50 to 250 ° C. and 1 to 50 hours, more preferably 70 to 200 ° C. and 1 to 20 hours. The reaction rate of the crosslinkable functional group in the solution is preferably less than 50%, more preferably less than 30%, from the viewpoint of preventing gelation of the prepolymer in the solution.

[Photosensitive composition]
A photosensitive composition can be obtained by adding a photosensitive agent to the coating composition according to the present invention. This photosensitive composition is excellent in the following points. When a resin film having a concavo-convex shape is obtained by a photolithographic method, a resist is unnecessary because the resin composition itself has photosensitivity. The obtained resin film simultaneously satisfies a low dielectric constant, a low water absorption rate and a high heat resistance. For this reason, the electrical characteristics of the element can be improved. In addition, since it is less susceptible to moisture and heat, it can improve reliability as well as electrical characteristics.

  The photosensitive composition contains the prepolymer, at least one photosensitive agent, and at least one solvent.

[Photosensitive agent]
The photosensitive agent used in the photosensitive composition refers to one that lowers the solubility in a developing solution when a reaction such as crosslinking or polymerization proceeds by light irradiation and the prepolymer has a high molecular weight. In this case, a photoinitiator or a sensitizer can be used in combination when the sensitizer itself has no or low sensitivity to irradiation light. Photosensitizers include photoinitiators (photoradical generators), photoacid generators, photobase generators, photocrosslinkers, and the like.

  Photoinitiators include benzoin alkyl ether derivatives, benzophenone derivatives, α-aminoalkylphenone series, oxime ester derivatives, thioxanthone derivatives, anthraquinone derivatives, acylphosphine oxide derivatives, glyoxyester derivatives, organic peroxides, trihalomethyltriazines Derivatives, titanocene derivatives and the like. Specifically, IRGACURE 651, IRGACURE 184, DAROCURE 1173, IRGACURE 500, IRGACURE 2959, IRGACURE 754, IRGACURE 907, IRGACURE 369, IRGACURE 1300, IRGACURE 819, IRGACURE 819, IRGACURE 819, IRGACURE 819, IRGACURE 819, IRGACURE 819 IRGACURE 784, IRGACURE OXE01, IRGACURE OXE02, IRGACURE 250 (Ciba Specialty Chemicals), KAYACURE DETX-S, KAYACURE CTX, KAYACURE BMS, KAYACURE 2-EAQ (Japan) Honka Pharmaceutical Co., Ltd.), TAZ-101, TAZ-102, TAZ-103, TAZ-104, TAZ-106, TAZ-107, TAZ-108, TAZ-110, TAZ-113, TAZ-114, TAZ-118, TAZ-122, TAZ-123, TAZ-140, TAZ-204 (Midori Chemical Co., Ltd.) etc. are mentioned.

  These photoinitiators can be used alone or in combination of two or more. Highly sensitive initiators are desirable because they can be cured with low irradiation energy. IRGACURE 907 (α-aminoalkylphenone type), IRGACURE 369 (α-aminoalkylphenone type), DAROCURE TPO (acylphosphine oxide type), IRGACURE OXE01 (oxime ester derivative), IRGACURE OXE02 (oxime ester derivative) are preferable, and DAROCURE OXE02 TPO, IRGACURE OXE01, and IRGACURE OXE02 are particularly preferable.

  Examples of the photoacid generator include diazodisulfone, triphenylsulfonium, iodonium salt, disulfone, and sulfone. Specifically, TPS-105, DPI-102, DPI-105, DPI-106, DPI-109, DPI-201, BI-105, MPI-103, MPI-105, MPI-106, MPI-109, BBI -102, BBI-103, BBI-105, BBI-106, BBI-109, BBI-110, BBI-201, BBI-301, TPS-102, TPS-103, TPS-105, TPS-106, TPS-109 , TPS-1000, MDS-103, MDS-105, MDS-109, MDS-205, BDS-109, DTS-102, DTS-103, DTS-105, NDS-103, NDS-105, NDS-155, NDS159 , NDS-165, DS-100, DS-101, SI-101, SI- 05, SI-106, SI-106, SI-109, PI-105, PI-105, PI-109, NDI-101, NDI-105, NDI-106, NDI-109, PAI-101, PAI-106, PAI-1001, NAI-100, NAI-1002, NAI-1003, NAI-1004, NAI-101, NAI-105, NAI-106, NAI-109, DAM-101, DAM-102, DAM-103, DAM- 105, DAM-201, Benzoin tosylate, MBZ-101, MBZ-201, MBZ-301, PYR-100, DNB-101, NB-101, NB-201, TAZ-100, TAZ-101, TAZ-102, TAZ -103, TAZ-104, TAZ-106, TAZ-1 07, TAZ-108, TAZ-109, TAZ-110, TAZ-113, TAZ-114, TAZ-118, TAZ-122, TAZ-123, TAZ-140, TAZ-201, TAZ-203, TAZ-204, NI-101, NI-1002, NI-1003, NI-1004, NI-101, NI-105, NI-106, NI-109 (Midori Chemical), WPAG-145, WPAG-170, WPAG-199, WPAG -281, WPAG-336, WPAG-367 (Wako Pure Chemical Industries, Ltd.) and the like.

  Examples of the photobase generator include Co amine complex, oxime carboxylic acid ester, carbamic acid ester, quaternary ammonium salt, and the like. Specifically, TPS-OH, NBC-101, ANC-101 ( Midori Chemical Co.).

  Examples of the photocrosslinking agent include bisazide series. The bisazide-based photocrosslinking agent decomposes the azide group upon irradiation with light to generate active nitrene, causes the addition of a prepolymer to a double bond and the insertion reaction to a C—H bond, thereby causing a crosslinking reaction. Bisazide photocrosslinking agents are preferred because of their high sensitivity. Specifically, 2,6-bis [3- (4-azidophenyl) -2-propenylidene] cyclohexanone, 2,6-bis [3- (4-azidophenyl) -2-propenylidene] -4-methylcyclohexanone 2,6-bis [3- (4-azidophenyl) -2-propenylidene] -4-ethylcyclohexanone, 2,6-bis [3- (4-azidophenyl) -2-propenylidene] -4-propylcyclohexanone P-azidophenylsulfone, m-azidophenylsulfone, 4,4′-diazidostilbene, 4,4′-diazidobenzalacetophenone, 2,3′-diazido-1,4-naphthoquinone, 4,4 ′ -Diazide diphenylmethane etc. are mentioned. Of these, 2,6-bis [3- (4-azidophenyl) -2-propenylidene] -4-methylcyclohexanone is particularly preferred.

  The photoinitiator aid is used in combination with a photoinitiator to promote the initiation reaction more than when the photoinitiator is used alone. Specific examples include amines, sulfones and phosphines. More specifically, triethanolamine, methyldiethanolamine, triisopropanolamine, Michler's ketone, 4,4'-diethylaminophenone, ethyl 4-dimethylaminobenzoate and the like can be mentioned.

  A sensitizer absorbs a radiation spectrum that is not absorbed by a photoinitiator and excites it, and energy transfer of the absorption energy to the photoinitiator causes an initiation reaction from the photoinitiator. Examples of sensitizers include benzophenone derivatives, anthraquinone derivatives, acetophenone derivatives and the like.

  The addition amount of the photosensitive agent is not particularly limited as long as the polymer is insolubilized at the time of development. If the amount is too small, a large amount of light irradiation energy is required. If the amount is too large, an adverse effect on the electrical properties and mechanical properties of the cured film appears. Desirably, it is 0.1-30 mass parts with respect to 100 mass parts of a prepolymer, More preferably, it is 1-10 mass parts.

[Method for forming uneven shape]
The photosensitive composition is coated on a substrate to form a photosensitive composition film, exposed to light, and developed to obtain a resin film having an uneven shape. The resin film finally obtained below is also simply referred to as a cured film.

[Film formation]
In the method of coating the photosensitive composition on a substrate to form a photosensitive composition film, first, the photosensitive composition is applied on the substrate to form a wet film. This wet film is pre-baked and dried to form a photosensitive composition film.

  As a method for forming this wet film, it is preferable to employ a coating method. Examples thereof include known coating methods such as spin coating, dip coating, spray coating, die coating, bar coating, doctor coating, extrusion coating, scan coating, brush coating, and potting. When used as an insulating film for an electronic device, the spin coating method or the scan coating method is preferable from the viewpoint of film thickness uniformity.

  The thickness of the wet film formed from the photosensitive composition can be appropriately set according to the shape of the cured film to be produced. For example, for the purpose of producing an insulating film or film, it is preferable to form a wet film of about 0.01 to 500 μm on the substrate, and more preferably 0.1 to 300 μm.

  After forming the wet film, pre-baking is performed to volatilize the solvent. The heating condition is preferably a temperature at which the solvent is volatilized and the additive such as the crosslinkable functional group of the prepolymer, the photosensitizer, the photoinitiator, and the sensitizer does not substantially react. Tenth quantile is desirable.

[exposure]
In the exposure, actinic radiation is applied to a desired pattern shape. X-rays, electron beams, ultraviolet rays, visible rays, and the like can be used as actinic rays, but those having a wavelength of 200 to 500 nm are desirable.

Actinic radiation that is irradiated to pattern a part of the film that is insoluble and includes light that has a wavelength that is absorbed by a photosensitizer, etc., and suitable light sources include X-rays, electron beams, ultraviolet rays, and visible rays it can. More preferred light sources are ultraviolet light and visible light, and the most preferred light source is an ultra high pressure mercury arc. The dose varies depending on the film thickness and the type of photosensitive agent used. For a 10 μm thick film, a suitable dose is 100 to 2,000 mJ / cm ² . By using an exposure apparatus such as an aligner or a stepper and exposing through a mask in a pressure mode, a vacuum contact mode, a proximity mode, or the like, a pattern of an exposed portion and an unexposed portion can be formed on the film composition.

  Subsequent to exposure, a bake step can be applied as needed. This step increases the reaction rate of the photochemically generated long-lived intermediate. Since these intermediates increase mobility during this step, they can move to increase the probability of contact with the reaction site and increase the reaction rate. As another method for increasing the mobility of these reactive intermediates, heating can be performed during exposure. Such a technique increases the sensitivity of the photosensitizer and the like. The baking temperature varies depending on the type of intermediate, but is preferably 50 to 180 ° C.

[developing]
The exposed film is developed with a solvent. Examples of the developing method include spraying, paddle, dipping, and ultrasonic methods. When the resin in the unexposed area is dissolved, the wafer is rinsed with a rinsing liquid as necessary, and is spun at a high speed to dry the film.

  As the developing solvent, the resin in the exposed area is insoluble or only slightly soluble, and the resin in the unexposed area uses a soluble solvent. That is, it is preferable to dissolve the unexposed resin. Aromatic hydrocarbons, dipolar aprotic solvents, ketones, esters, ethers and halogenated hydrocarbons can be mentioned.

  Aromatic hydrocarbons include benzene, toluene, xylene, ethylbenzene, cumene, mesitylene, tetralin, methylnaphthalene and the like. Examples of the dipole aprotic solvents include N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, γ-butyrolactone, dimethyl sulfoxide and the like. Examples of ketones include cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, methyl amyl ketone, and the like.

  Examples of ethers include tetrahydrofuran, pyran, dioxane, dimethoxyethane, diethoxyethane, diphenyl ether, anisole, phenetole, diglyme, and triglyme. Esters include ethyl lactate, methyl benzoate, ethyl benzoate, butyl benzoate, benzyl benzoate, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether Propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate and the like. Examples of halogenated hydrocarbons include carbon tetrachloride, chloroform, methylene chloride, tetrachloroethylene, chlorobenzene, dichlorobenzene and the like.

  Rinse is carried out as necessary, but the rinsing solution is not as highly soluble as the prepolymer as the developing solution, and is not particularly limited as long as it is compatible with the developing solution. Examples include ketones and esters.

  Examples of alcohols include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, 3-pentanol, tert-amyl alcohol, cyclohexanol and the like. It is done.

  The solvent-developed film is baked to remove the solvent as necessary. Baking can be performed on a hot plate or in an oven, preferably at 80 to 150 ° C. for 0.5 to 60 minutes.

  After forming a desired pattern, a heat resistant final pattern (cured film) is obtained by heat treatment. The heating condition is preferably about 150 to 250 ° C. for about 1 to 120 minutes, more preferably about 160 to 200 ° C. for about 2 to 60 minutes.

  As the heating device, a hot plate, an oven, and a furnace (furnace) are preferable, and examples of the heating atmosphere include an inert gas atmosphere such as nitrogen and argon, air, oxygen, reduced pressure, and the like, and an inert gas atmosphere and reduced pressure are preferable. In order to ensure the surface smoothness of the thin film and improve the fine space embedding property of the thin film, it is preferable to add a prebaking process of about 50 to 180 ° C. or to carry out the heating process in several stages. . The reaction rate of the crosslinkable functional group (A) in the cured film is preferably 30 to 100%. By setting the reaction rate to 30% or more, the heat resistance and chemical resistance of the cured film are improved. From this viewpoint, the reaction rate is more preferably 50% or more, and most preferably 70% or more.

[Descam]
Depending on the exposure and development conditions, a slight residual film may be observed in the unexposed area, and descum may be performed as necessary. Examples of the descum etching gas include oxygen gas, argon gas, and fluorocarbon gas. As etching conditions, it is preferable that the remaining film can be removed and the influence on the film of the exposed portion is minimized. The gas flow rate is 10 to 200 sccm (the unit is a volume (cm ³ ) flow rate per minute at a specified temperature), the processing pressure is 1 to 50 Pa, the output is 10 to 1,000 W, the processing time is 1 to 600 seconds, and the like. .

[Additive]
A cured film obtained from the coating composition (which may be a photosensitive composition or a non-photosensitive composition) may be used as an insulating film or the like while being adhered on a substrate. it can. In this case, an adhesion promoter can be used to improve the adhesion between the cured film and the substrate. Examples of the adhesion promoter include silane coupling agents, titanate coupling agents, aluminum coupling agents, and the like, and silane coupling agents such as epoxy silanes, aminosilanes, and vinyl silanes are more preferable. Epoxy silanes include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane. Illustrated. Examples of aminosilanes include aliphatic aminosilanes such as 3-aminopropylmethyldiethoxysilane and 3-aminopropyltriethoxysilane, aminophenyltrimethoxysilane, aminophenyltriethoxysilane, and N-phenyl-3-aminopropyltrimethoxy. Aromatic group aminosilanes such as silane are exemplified. Examples of vinyl silanes include vinyl trichlorosilane, vinyl trimethoxy silane, vinyl triethoxy silane, and styryl trimethoxy silane.

  As a method for applying the adhesion promoter, a method of treating the substrate with the adhesion promoter before application of the coating composition or a method of adding the adhesion promoter to the coating composition is preferable. As a method for treating the substrate with an adhesion promoter, in the case of aminosilanes, a method of spin-coating the substrate as a 0.01 to 3 mass% alcohol-based solution can be mentioned. As the alcohol, methanol, ethanol, 2-propanol, and propylene glycol monomethyl ether are preferable. In the method of adding the adhesion promoter to the prepolymer solution, the addition amount of the adhesion promoter is preferably 0.05 to 10% by mass, more preferably 0.1 to 5% by mass with respect to the prepolymer contained. If the addition amount of the adhesion promoter is small, the effect of improving the adhesiveness is not sufficient, and if it is too much, the electrical characteristics and heat resistance are lowered.

[Use of cured film]
Applications of the cured film produced using the prepolymer of the present invention include protective films, film materials for various batteries such as fuel cells, photoresists, optical waveguides, nonlinear optical materials, coating materials, electronic members, sealing Agents, overcoat agents, transparent film materials, heat-resistant and low moisture-absorbing film materials, weather-resistant paints, water-repellent agents, oil-repellent agents, moisture-proof coating agents, non-adhesive coating agents, and the like. In particular, the use of an insulating film, a film, or an optical transmission body for an electronic device or a multilayer wiring board is preferable. The present invention provides an electronic component, an electrical component, or an optical component having a cured film manufactured using the composition containing the prepolymer.

  Among electronic components, electrical components, and optical components to which the cured film according to the present invention can be applied, electronic devices include individual semiconductors such as diodes, transistors, compound semiconductors, thermistors, varistors, thyristors, and DRAMs (dynamic random access). Memory, SRAM (Static Random Access Memory), EPROM (Erasable Programmable Read Only Memory), Mask ROM (Mask Read Only Memory), EEPROM (Electrically Eraseable Programmable Read Memory) Only memory), memory elements such as flash memory, theoretical circuit elements such as microprocessors, DSPs and ASICs, and integrated circuit elements such as compound semiconductors represented by MMIC (monolithic microwave integrated circuits) , Hybrid integrated circuits (Hybrid IC), light emitting diode, a photoelectric conversion element such as a charge coupled device, an amorphous silicon TFT (thin film transistor), a display element such as a polysilicon TFT and the like.

  Among the electronic / electrical components to which the cured film (mainly insulating film) according to the present invention can be applied, the multilayer wiring board includes various substrates for mounting electronic devices and the like, and includes a printed wiring board and a build-up wiring board. And high-density wiring boards such as MCM substrates and interposers. Examples of the insulating film in these electronic / electrical parts include a buffer coat film, a passivation film, an interlayer insulating film, a rewiring insulating film, and an alpha ray shielding film.

  The optical transmission body refers to a member that transmits light and has functions such as transmission, branching, amplification, and demultiplexing / multiplexing. Optical transmitters include, for example, optical fibers, rod lenses, optical waveguides, optical splitters, optical multiplexers, optical demultiplexers, optical attenuators, optical switches, optical isolators, optical transmission modules, optical reception modules, couplers, and deflections. This means the optical element, the optical wavelength conversion element, the optical modulation element, the optical integrated circuit, the optical / electrical hybrid circuit, the substrate itself, or the optical transmission portion thereof.

  The wavelength of light used in the optical transmission body is preferably in the range of 600 to 1,600 nm. Among these, since it is easy to obtain components such as a laser, the 650 nm band, the 850 nm band, the 1,300 nm band, or the 1,550 nm band is preferable.

  When the optical transmitter is used as a so-called electro-optic (EO) material that modulates and controls the propagation of light with an external electric field and performs phase change, directional coupling, mode conversion, guided wave path conversion, etc., a nonlinear optical dye It is preferable to dope. As the nonlinear optical dye, a compound having a push-pull electronic structure having a long π electron conjugated system and having an electron donating group and an electron withdrawing group is preferable. Specific examples include azobenzene dyes and polyene dyes.

[Improvement of cured film properties]
In the application of the insulating film for electronic devices or the insulating film for multilayer wiring boards using the cured film, it is preferable to provide pores in the insulating film in order to obtain an insulating film having a lower relative dielectric constant. Examples of the method for introducing pores include the following methods (a) and (b).

  (A) In the coating composition, the prepolymer of the present invention and a polymer having a low thermal decomposition temperature (hereinafter referred to as a “thermally decomposable polymer”) are combined, and the thermally decomposable polymer portion is added at the time of forming a cured film. How to remove.

  (B) A method in which fine particles are added to the coating composition and the fine particle portions are removed during or after the formation of the cured film.

  In the method (a), examples of the thermally decomposable polymer include aliphatic polyethers, aliphatic polyesters, acrylic polymers, and styrene polymers. The molecular weight of the thermally decomposable polymer is preferably 1,000 to 100,000, more preferably 1,000 to 50,000. When the molecular weight is within this range, the compatibility with the prepolymer of the present invention can be secured in the coating composition, which is preferable. As a method of combining the prepolymer of the present invention and the thermally decomposable polymer, a coating composition containing the prepolymer and the thermally decomposable polymer is prepared, and this is applied onto a substrate, and then the solvent is volatilized. Examples thereof include a method of obtaining a composite film by heat treatment, a method of forming a composite by blocking or grafting a prepolymer and a thermally decomposable polymer, and blending this composite into a coating composition. A known method can be applied as the method of blocking or grafting. For example, a method in which a thermally decomposable polymer having a fluorine-containing aromatic ring or a phenolic hydroxyl group at the terminal is prepared and co-condensed during the condensation reaction of prepolymer synthesis can be exemplified. Since the condensation reaction of the prepolymer proceeds by the reaction mechanism of the above formula (2) or (3), the terminal fluorine-containing aromatic ring or phenolic hydroxyl group is bonded to the prepolymer chain. Here, when the thermally decomposable polymer has a fluorine-containing aromatic ring or a phenolic hydroxyl group at one end, a prepolymer grafted with the thermally decomposable polymer can be obtained. When the thermally decomposable polymer has a fluorine-containing aromatic ring or a phenolic hydroxyl group at both ends, a block body of a prepolymer and a thermally decomposable polymer can be obtained.

  Since the thermal decomposition temperature of the thermally decomposable polymer is low, it is selectively decomposed and removed by heating during the formation of the cured film, and the removed part becomes a void. The porosity can be controlled by the amount of the thermally decomposable polymer added to the coating composition. The amount of the thermally decomposable polymer added is usually preferably from 5 to 80% by volume, more preferably from 10 to 70% by volume, based on the prepolymer.

  In the method (b), inorganic fine particles are preferable as fine particles dispersed in the coating composition according to the present invention. Examples of the inorganic fine particles include silica and metal fine particles. The fine particles are dissolved and removed by acid treatment or the like after film formation, and the removed portions become pores. The porosity can be controlled by the amount of fine particles added. The addition amount of the fine particles is usually preferably 5 to 80% by volume, more preferably 10 to 70% by volume with respect to the prepolymer.

  The cured film according to the present invention is preferably combined with another film. For example, when applied as a semiconductor element passivation film or an interlayer insulating film for a semiconductor element, it is preferable to form an inorganic film in the lower layer and / or upper layer of the cured film.

  As the inorganic film, a so-called PSG film or BPSG film formed by atmospheric pressure, reduced pressure, plasma chemical vapor deposition (CVD) method or coating method, for example, a silicon oxide film doped with phosphorus and / or boron as necessary, Examples thereof include a silicon oxide film, a silicon nitride film, a silicon oxynitride film, a SiOC film, and a spin-on-glass (SOG) film.

  By forming the inorganic film between the cured film and the metal wiring, the metal wiring can be prevented from being peeled off, and an etching process such as a damascene shape can be easily performed. The inorganic film is preferably formed on the upper layer of the cured film after partially removing the cured film by an etch back method or a CMP (Chemical Mechanical Polishing) method.

  When forming an inorganic film on the upper layer of the cured film, if the adhesion between the cured film and the inorganic film is not sufficient, or if the film is reduced when forming the inorganic film, the following (I) or (II) It is preferable to apply the method.

  (I) Method for forming a multilayer inorganic film: When a silicon oxide film is formed by a plasma CVD method, when film loss occurs due to the gas composition used, a film such as a silicon nitride film or an atmospheric pressure CVD-silicon oxide film is first used A thin film of an inorganic film that does not decrease is formed. Next, a silicon oxide film is formed using this thin film as a barrier layer.

  (II) Method of treating a cured film with energy rays: In some cases, the adhesion at the interface between the cured film and the inorganic film can be improved by treatment with energy rays. As energy beam processing, electromagnetic waves in a broad sense including light, that is, UV light irradiation, laser light irradiation, microwave irradiation, or the like, or processing using an electron beam, that is, electron beam irradiation, glow discharge processing, corona discharge processing. Examples of the treatment include plasma treatment. Among these, UV light irradiation, laser light irradiation, corona discharge processing, and plasma processing are preferable as a processing method suitable for the mass production process of semiconductor elements.

  Plasma treatment is more preferable because it causes less damage to the semiconductor element. The apparatus for performing the plasma treatment is not particularly limited as long as a desired gas can be introduced into the apparatus and an electric field can be applied, and a commercially available barrel type or parallel plate type plasma generator can be used as appropriate. The gas introduced into the plasma apparatus is not particularly limited as long as it effectively activates the surface, and examples thereof include argon, helium, nitrogen, oxygen, and a mixed gas thereof. Further, examples of the gas that activates the surface of the cured film and has almost no film loss include a mixed gas of nitrogen and oxygen and nitrogen gas.

  The present invention will be described more specifically with reference to the following examples and comparative examples, but the present invention is not limited thereto. Each measurement item was measured by the following method.

[Molecular weight]
The number average molecular weight in terms of polystyrene was determined from the vacuum-dried prepolymer powder by gel permeation chromatography (GPC). Tetrahydrofuran was used as the carrier solvent.

[Reaction rate of crosslinkable functional group]
The resin film on the wafer was measured by Raman spectroscopy (manufactured by Thermo, ALMEGA), and the reaction rate was calculated from the amount of crosslinkable functional groups (double bonds in the following examples). As a reference sample, a resin film before exposure was used.

[Crosslinking start temperature]
It calculated | required using the differential scanning calorimetry (Differential Scanning Calorimetry) (the SII nanotechnology company make, DSC6220). The dried (prepolymer) sample powder was used, and the measurement conditions were a heating rate of 10 ° C./min and a nitrogen stream. The temperature at which the exothermic peak was maximized was taken as the crosslinking initiation temperature.

[Relative permittivity]
A 20% by mass solution obtained by dissolving the vacuum-dried prepolymer powder in cyclohexanone was filtered through a PTFE filter having a pore diameter of 5.0 μm. Using the obtained solution, a wet film having a thickness of about 1 μm was formed on a 4-inch silicon wafer by spin coating. The spin conditions were 1,000 to 5,000 revolutions per minute for 30 seconds, and final baking was performed in a nitrogen atmosphere using a vertical furnace at 190 ° C. for 60 minutes. Subsequently, a relative dielectric constant of 1 MHz was obtained by performing CV measurement using a mercury prober (SSM-495, manufactured by SSM). As the cured film thickness, a value obtained by a spectroscopic ellipsometer was used.

[exposure]
The exposure was performed by irradiating a high-pressure mercury lamp using UL-7000 (manufactured by Quintel). In addition, about the unexposed part, the light-shielding part was formed using metal foil or a mask.

[Example 1]
To a 100 mL glass four-necked flask equipped with a Dimroth condenser, thermocouple thermometer, and mechanical stirrer, parachloromethylstyrene (0.58 g), 1,1,1-tris (4-hydroxyphenyl) ethane (1.1 g) ), Dimethylacetamide (hereinafter referred to as DMAc) (15.2 g). The mixture was heated on an oil bath with stirring, and potassium carbonate (2.3 g) was quickly added when the liquid temperature reached 60 ° C. The mixture was heated at 60 ° C. for 14 hours while stirring was continued. Next, a solution of perfluorobiphenyl (1.4 g) in DMAc (15.2 g) was added, and the mixture was further heated at 60 ° C. for 28 hours. Thereafter, the reaction solution was cooled to room temperature and gradually added dropwise to about 250 mL of vigorously stirred 0.5N aqueous hydrochloric acid for reprecipitation. After filtration, and further washed twice with pure water, vacuum drying was performed at 50 ° C. for 12 hours to obtain a white powdery prepolymer (2.6 g).

  The obtained prepolymer had an ether bond and a vinyl group which is a crosslinkable functional group, and had a molecular weight of 5,383. The crosslinking temperature of the prepolymer was 170 ° C. The relative dielectric constant of the cured film formed by the above-described method using the prepolymer was 2.7.

[Example 2]
Chloromethylstyrene (17.5 g), 1,1,1-tris (4-hydroxyphenyl) ethane (50.7 g) in a 2 L glass four-necked flask equipped with a Dimroth condenser, thermocouple thermometer, and mechanical stirrer DMAc (612.3 g) was charged. The mixture was heated on an oil bath with stirring, and potassium carbonate (102.5 g) was quickly added when the liquid temperature reached 60 ° C. The mixture was heated at 60 ° C. for 17 hours while stirring was continued. Next, a solution of perfluorobiphenyl (72.0 g) in DMAc (648.4 g) was added, and the mixture was further heated at 60 ° C. for 22 hours. Thereafter, the reaction solution was cooled to room temperature and gradually dropped into about 5 L of vigorously stirred 0.5 N hydrochloric acid aqueous solution for reprecipitation. After filtration, and further washed twice with pure water, vacuum drying was performed at 50 ° C. for 12 hours to obtain a white powdery prepolymer (122.6 g). The obtained prepolymer had an ether bond and a vinyl group which is a crosslinkable functional group, and had a molecular weight of 6,494.

[Example 3]
In a sample bottle, 1.35 g of the prepolymer synthesized in Example 1, 1.66 g of propylene glycol monomethyl ether acetate (hereinafter referred to as PGMEA), and 0.0402 g of DAROCUR TPO as a photosensitizer were dissolved. The prepolymer solution was spin-coated on a Si wafer at 1,000 revolutions per minute for 30 seconds, and heated on a hot plate at 100 ° C. for 90 seconds. This was exposed to an irradiation energy of 1,530 mJ / cm ² . Paddle development was performed for 20 seconds using PGMEA, and spin drying was performed at 2,000 rpm for 30 seconds. Thereafter, curing was performed at 190 ° C. for 1 hour in a nitrogen stream. The film thickness was 12.53 μm. This film thickness was 58% of the reference film thickness not subjected to the development process after exposure. The reaction rate of the crosslinkable functional group was 100% (the signal of the crosslinkable functional group had disappeared).

By using the crosslinkable fluorine-containing aromatic prepolymer of the present invention, curing is possible at a low temperature, and the production of a semiconductor element or the like is facilitated.

Claims (11)

Following formula (1)

[Wherein, R ¹ represents a monovalent organic group having a crosslinkable functional group, and R ² represents a haloalkyl group having 8 or less carbon atoms. And a hydrocarbon aromatic compound (A) represented by the following formula (2):

[Wherein, n is an integer of 0 to 3; a and b each independently represents an integer of 0 to 3, and Rf ¹ and Rf ² may be the same or different and each may contain 8 or less carbon atoms. F represents a fluorine alkyl group, and F in the aromatic ring represents that all hydrogen atoms in the aromatic ring are substituted with fluorine atoms. And a compound having three or more phenolic hydroxyl groups (C) in the presence of a dehydrohalogenating agent to obtain a crosslinkable functional group and an ether. A crosslinkable fluorine-containing aromatic prepolymer having a bond and a number average molecular weight of 1,000 to 500,000. R ² represents —R ³ —X [wherein R ³ represents an alkylene group having 8 or less carbon atoms, and X represents a chlorine atom or a bromine atom. The crosslinkable fluorine-containing aromatic prepolymer according to claim 1, which is a haloalkyl group represented by the formula: The crosslinkable fluorine-containing aromatic prepolymer according to claim 2, wherein R ³ is an alkylene group having 4 or less carbon atoms. The crosslinkable group according to any one of claims 1 to 3, wherein R ¹ is a group selected from the group consisting of a vinyl group, a methacryloyl group, a methacryloyloxy group, an acryloyl group, an acryloyloxy group, and an ethynyl group. Fluoroaromatic prepolymer.   The bridge according to any one of claims 1 to 4, wherein the hydrocarbon aromatic compound (A) is a compound selected from the group consisting of chloromethylstyrene, chloroethylstyrene, chloropropylstyrene, and bromomethylstyrene. Fluorinated aromatic prepolymer.   The fluorine-containing aromatic compound (B) is perfluorobenzene, perfluorotoluene, perfluoroxylene, perfluorobiphenyl, perfluoroterphenyl, perfluoro (1,3,5-triphenylbenzene), and perfluoro (1,2,4-triphenyl). The crosslinkable fluorine-containing aromatic prepolymer according to any one of claims 1 to 5, which is a compound selected from the group consisting of phenylbenzene). The compound (C) having three or more phenolic hydroxyl groups is trihydroxybenzene, trihydroxybiphenyl, trihydroxynaphthalene, 1,1,1-tris (4-hydroxyphenyl) ethane, tris (4-hydroxyphenyl) benzene. The crosslinkable fluorine-containing aromatic prepolymer according to claim 1, wherein the crosslinkable fluorine-containing aromatic prepolymer is selected from the group consisting of tetrahydroxybenzene, tetrahydroxybiphenyl, tetrahydroxybinaphthyl, and tetrahydroxyspiroindane. Cured product formed by curing the crosslinkable fluorinated aromatic prepolymer according to any one of claims 1-7. The manufacturing method of hardened | cured material which hardens the crosslinkable fluorine-containing aromatic prepolymer as described in any one of Claims 1-7 at 40-250 degreeC. Coating composition comprising a crosslinkable fluorinated aromatic prepolymer and a solvent according to any one of claims 1-7. An electronic component, an electrical component or an optical component having the cured product according to claim 8 .