JP2005266757A - Photosensitive resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition providing a polyimide resin film having extremely low residual stress after curing, and also to provide a method for forming a cured relief pattern by using the composition. <P>SOLUTION: The photosensitive resin composition contains: (a) 100 parts by mass of polyamide acid ester having 3,000 to 100,000 number average molecular weight expressed by the general formula (1), the polyamide acid ester containing a block 1 composed of m of unit 1 (amide acid ester) prepared by condensation of X carboxylic acid and Y amine, and a block 2 composed of n of unit 2 (amide acid ester) prepared by condensation of X' carboxylic acid and Y' amine; (b) 1 to 20 parts by mass of a photopolymerization initiator; and (c) 30 to 600 parts by mass of solvent. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a heat-sensitive photosensitive resin useful for the production of electrical / electronic materials such as semiconductor devices and multilayer wiring boards. More specifically, the present invention relates to a photosensitive polyamic acid ester composition in which a cured polyimide coating film has extremely low residual stress and high heat resistance.

Polyimide resin is attracting attention as a material for microelectronics due to its high thermal and chemical stability, low dielectric constant, and excellent planarization ability, and is used as a semiconductor surface protective film, interlayer insulating film, or Widely used as a material for multi-chip modules.
In the case of manufacturing a semiconductor device using a polyimide resin, conventionally, a non-photosensitive polyimide precursor is applied on a substrate to form a coating film, and after heating to convert to a polyimide resin, a lithography technique is used. Thus, a method for forming a desired pattern has been used. Specifically, on the polyimide resin film, a photoresist relief pattern is formed using a photoresist and a photomask having a pattern, and then the polyimide resin film is patterned by etching. A relief pattern forming method has been used. However, in this method, first, a relief pattern of a photoresist to be a mask is formed on the polyimide resin film, and then the polyimide resin film is etched, and finally the unnecessary photoresist is removed. The process was complicated because it had to be done. In addition, since it is an indirect relief pattern forming method, the resolution is low, and it is necessary to use a toxic substance such as hydrazine as a solvent for etching.

  In recent years, in order to overcome the above problems, a method for introducing a photopolymerizable photosensitive group into a polyimide precursor and directly forming a relief pattern on the polyimide precursor coating has been developed and put into practical use. . For example, a polyimide precursor obtained by bonding a compound having a double bond to a polyamic acid derivative via an ester bond, an amide bond, an ionic bond, or the like (hereinafter also referred to as a photosensitive polyimide precursor), and a photopolymerization initiator. The polyimide precursor of the exposed part of the coating film is formed by forming a coating film by applying a photosensitive resin composition containing etc. on the substrate and exposing the coating film through a photomask having a pattern. A method is proposed in which a relief pattern made of a polyimide precursor is formed by insolubilization and then subjected to a development treatment, and then converted to a cured relief pattern made of polyimide resin by heating to remove the photosensitive group component. (See Non-Patent Document 1). This technology is generally called photosensitive polyimide technology. Since the photosensitive polyimide technology overcomes the problems associated with the conventional process using a non-photosensitive polyimide precursor, in recent years, a relief pattern made of a polyimide resin is frequently formed by the photosensitive polyimide technology.

However, when the photosensitive polyimide precursor is formed on a silicon wafer and converted into a polyimide resin by heating, there may be a problem that the entire silicon wafer is warped due to residual stress at the time of curing. Moreover, this tendency is becoming more problematic in the case of a silicon wafer having a large diameter that has recently been used. In addition, when a polyimide thin film is formed as a buffer coat film on a passivation film made of silicon nitride or the like used for LSIs with a large amount of heat, such as MPU, if the residual stress of the polyimide film is large, the change with time and thermal history Since there is a possibility that cracks may occur in the lower passivation film due to the application of, it is required to reduce the residual stress in the polyimide resin film.
In general, the residual stress of a thin film is the room temperature from the glass transition temperature (hereinafter also referred to as Tg) of the product of the Young's modulus (hereinafter also referred to as E) and the thermal expansion coefficient (hereinafter also referred to as CTE) of the thin film. It is known to be proportional to the value integrated over the range up to. Accordingly, it has been proposed to reduce the value of E or CTE as a method of reducing the residual stress of the polyimide resin film while maintaining heat resistance. For example, there has been proposed a photosensitive resin composition comprising a polyamic acid obtained by copolymerizing 5 to 50% by weight of a silicone-based diamine as a diamine component, a polyfunctional acrylate having a molecular weight of 500 or less, and a sensitizer as essential components ( Patent Document 1), there is a description that a polyimide resin film obtained by curing the composition has a low elastic modulus (E is a kind of elastic modulus). However, in the polyimide resin film obtained by this method, E decreases as the copolymerization amount of the silicone diamine increases, but Tg also decreases at the same time. That is, another problem arises that the heat resistance of the thin film also decreases.

Further, a precursor 1 that becomes a polyimide resin having a CTE of 2 × 10 ⁻⁵ / K or less after curing, and a precursor 2 that becomes a polyimide resin having a CTE of 2 × 10 ⁻⁴ / K or less and a Tg of less than 350 ° C. after curing. And a photosensitive resin composition obtained by block copolymerization of the precursor 1 and the precursor 2 have been proposed (see Patent Document 2), and the composition is cured. There is a description that the resulting polyimide resin film has low residual stress. However, since the polyimide coating film obtained by this method has a low CTE and a high E and Tg, there is an insufficient point in terms of a decrease in residual stress. In addition, since the CTE is lowered by causing a high degree of packing between polyimide molecules, local stress concentration is unavoidable, and as a result, the crack problem of the passivation film may not be avoided. there were.
Further, 15 to 70 mol% of the total aromatic tetracarboxylic acid is derived from pyromellitic dianhydride and 15 to 50 mol% is derived from oxydiphthalic dianhydride, and the polyimide thin film remains after curing. A polyamic acid ester having a stress of 33 MPa or less has been proposed (see Patent Document 3), and there is a description that it has Tg in a region of 220 to 280 ° C and a region of 320 to 380 ° C. The invention described in Patent Document 3 achieves both high Tg and low residual stress by block copolymerization, but further reduction of residual stress is required.

Japanese Patent Publication No. 05-049215 JP 2002-040658 A International Publication No. 00/43439 Pamphlet Yamaoka, Omote, “Polyfile”, 1990, 27, No. 2, pp. 14-18

  The present invention provides a polyamic acid ester composition in which a cured polyimide coating film is homogeneous, has low residual stress and high heat resistance at the same time, and gives a uniform relief relief pattern, and curing using the composition It is an object to provide a method for forming a relief pattern.

As a result of studying the above-described problems of the prior art, the present inventor has found that it is difficult for Tg and E to move together to achieve both low residual stress and high heat resistance. That is, in a polyimide obtained by curing a polyamic acid ester obtained by randomly copolymerizing a unit unit A which gives polyimide A having a high E and Tg and a unit unit B giving a polyimide B having a low E and Tg, both E and Tg Only intermediate materials between polyimide A and polyimide B can be obtained.
The present inventor uses a polyimide obtained by curing a polyamic acid ester obtained by block copolymerization of the unit unit A and the unit unit B, E is between the polyimide A and the polyimide B, and the higher Tg is the polyimide A. The idea was that an equivalent product could be obtained and sufficient heat resistance could be developed to withstand the manufacturing process of the semiconductor device. And it discovered that E was reduced significantly by using the polyimide B which made Tg 0 degrees C or less, and also by making Tg of polyimide A 150 degrees C or more, it discovered that the said idea was realizable and came to this invention.

（式中、ＸとＸ’はそれぞれ独立して炭素数６〜３２の４価の有機基であり、Ｙは炭素数４〜３０の２価の有機基であり、Ｙ’は炭素数４〜３０の２価の有機基およびケイ素数２〜５０の２価のケイ素含有基からなる群から選ばれる基であり、ＲおよびＲ’はそれぞれ独立してオレフィン性二重結合を有する１価の基である。） That is, the present invention is the following photosensitive resin composition and method for forming a cured relief pattern.
1) (a) Block 1 consisting of m unit units 1 (amidate ester) obtained by condensing at least X carboxylic acid represented by the following general formula (1) and Y amine, X ′ carboxylic acid and Y ′ amine A polyamic acid ester having a number average molecular weight of 3,000 to 100,000, comprising a block 2 composed of n unit units 2 (amide acid ester) condensed with bismuth, and obtained by heat curing Has at least one glass transition temperature obtained from a temperature dispersion curve by a dynamic viscoelasticity measurement method in each of the region A of −150 to 0 ° C. and the region B of 150 to 380 ° C. In region C between the region B and the region B, 100 parts by mass of a polyamic acid ester having no glass transition temperature, (b) 1 to 20 parts by mass of a photopolymerization initiator, and (c) 30 to 600 parts by mass of a solvent A photosensitive resin composition which comprises.

(In the formula, X and X ′ are each independently a tetravalent organic group having 6 to 32 carbon atoms, Y is a divalent organic group having 4 to 30 carbon atoms, and Y ′ is 4 to 4 carbon atoms. 30 is a group selected from the group consisting of 30 divalent organic groups and 2 to 50 silicon-containing divalent silicon-containing groups, and R and R ′ are each independently a monovalent group having an olefinic double bond .)

（式中、Ｒ₁は２価の有機基であり、Ｒ₂、Ｒ₃、及びＲ₄は、それぞれ独立して１価の有機基、及びハロゲン基からなる群から選ばれる基である。）
３）溶媒が、１５０〜３００℃に沸点を有する有機溶媒を１０〜１００質量％含有する溶媒であることを特徴とする上記１）又は２）に記載の感光性樹脂組成物。
４）上記１）〜３）のいずれかに記載の感光性樹脂組成物を基材に塗布して乾燥することにより該基材上に塗膜を形成する工程、パターンを有するフォトマスクを介して、又は直接に該塗膜に紫外線を照射する工程、現像液で現像することにより該塗膜の露光されなかった部分を除去して該基材上にレリーフパターンを形成する工程、該レリーフパターンを加熱することによりポリイミド樹脂からなる硬化レリーフパターンを該基材上に形成する工程、の各工程を包含することを特徴とする硬化レリーフパターンの形成方法。 2) The photosensitive resin composition as described in 1) above, wherein the solvent is a solvent containing 10 to 100% by mass of a solvent represented by the following general formula (2).

(Wherein R ₁ is a divalent organic group, and R ₂ , R ₃ , and R ₄ are each independently a group selected from the group consisting of a monovalent organic group and a halogen group.)
3) The photosensitive resin composition as described in 1) or 2) above, wherein the solvent is a solvent containing 10 to 100% by mass of an organic solvent having a boiling point at 150 to 300 ° C.
4) A step of forming a coating film on the substrate by applying the photosensitive resin composition according to any one of 1) to 3) above to a substrate and drying, through a photomask having a pattern Or a step of directly irradiating the coating film with ultraviolet light, a step of removing an unexposed portion of the coating film by developing with a developer and forming a relief pattern on the substrate, and the relief pattern A method of forming a cured relief pattern comprising the steps of: forming a cured relief pattern comprising a polyimide resin on the substrate by heating.

  In the photosensitive resin composition of the present invention, the cured polyimide resin film is homogeneous and excellent in surface smoothness, and simultaneously exhibits low residual stress and high heat resistance. Furthermore, according to the pattern forming method of the present invention, a cured relief pattern having both low residual stress and high heat resistance can be formed on the substrate.

（式中、ＸとＸ’はそれぞれ独立して炭素数６〜３２の４価の有機基であり、Ｙは炭素数４〜３０の２価の有機基であり、Ｙ’は炭素数４〜３０の２価の有機基およびケイ素数２〜５０の２価のケイ素含有基からなる群から選ばれる基であり、ＲおよびＲ’はそれぞれ独立してオレフィン性二重結合を有する１価の基である。） The present invention will be specifically described below.
(A) Polyamic acid ester The polyimide resin film obtained by heat-curing the photosensitive resin composition of the present invention has a glass transition temperature in each of the region A of −150 to 0 ° C. and the region B of 150 to 380 ° C. At least one is provided, and the region C between the region A and the region B does not have a glass transition temperature (hereinafter, this feature is referred to as “Tg requirement”). In addition, the glass transition temperature in this invention shall be defined with the peak of Tandelta obtained from the temperature dispersion curve by a dynamic viscoelasticity measuring method.
The polyamic acid ester (hereinafter referred to as a blocky polyamic acid ester) contained in the photosensitive resin composition of the present invention is a unit unit 1 whose main chain is a condensation of X carboxylic acid of formula (1) and Y amine. And a block 2 mainly comprising a unit unit 2 obtained by condensing the X ′ carboxylic acid and Y ′ amine of the following formula (1). Further, as long as the Tg requirement is not violated, another unit having a molecular weight smaller than that of both blocks (hereinafter referred to as unit unit 3) may be further included.

(In the formula, X and X ′ are each independently a tetravalent organic group having 6 to 32 carbon atoms, Y is a divalent organic group having 4 to 30 carbon atoms, and Y ′ is 4 to 4 carbon atoms. 30 is a group selected from the group consisting of 30 divalent organic groups and 2 to 50 silicon-containing divalent silicon-containing groups, and R and R ′ are each independently a monovalent group having an olefinic double bond .)

The block 1 and the block 2 described above may be directly coupled or may be coupled via the unit unit 3. Further, the same type or different types of unit units 3 may be bonded to both ends of the main chain. The block polyamic acid ester can be synthesized by subjecting a plurality of different tetracarboxylic acid diesters to a condensation reaction with diamines as described later.
The above-mentioned block 1 is a part for expressing Tg in the region B at 150 to 380 ° C. in a polyimide resin film obtained by heat-curing a block polyamic acid ester. Therefore, it is preferable that the block is composed of only repetitions of the unit unit 1 described above, but it is not excluded to include a small amount of units other than the unit unit 1 as long as the Tg requirement is not violated.
Similarly, the above-mentioned block 2 is a portion for reducing E and expressing Tg in the region A at −150 to 0 ° C. in a polyimide resin film obtained by heat-curing a block polyamic acid ester. . Therefore, although it is preferable that the block is composed of only repetitions of the unit unit 2 described above, it is not excluded to include a small amount of units other than the unit unit 2 as long as the Tg requirement is not violated.
Moreover, the unit unit 3 described above does not have an active role for expressing Tg or E in a polyimide resin film obtained by heat-curing a block polyamic acid ester. Therefore, as the polyimide resin film, any unit unit or content that does not express Tg in the region C can be used.

In the block polyamic acid ester, the X group in the unit unit 1 and the X ′ group in the unit unit 2 are derived from a tetracarboxylic dianhydride used as a raw material.
The tetracarboxylic dianhydride that can be suitably used as the main raw material of the block polyamic acid ester is a tetracarboxylic dianhydride in which the X and X ′ groups are tetravalent aromatic groups having 6 to 32 carbon atoms ( Hereinafter, simply referred to as aromatic tetracarboxylic dianhydride), for example, pyromellitic dianhydride, 4,4′-oxydiphthalic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic Acid dianhydride, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ) Ether dianhydride, bis (3,4-dicarboxyphenyl) sulfide dianhydride, bis (4- (4-aminophenoxy) phenyl) sulfone, bis (3,4-dicarboxyphenyl) sulfone Hong dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (3,4-di Carboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 1,3-bis (3,4-dicarboxyphenoxy) benzene dianhydride, 1,4-bis (3 4-dicarboxyphenoxy) benzene dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) biphenyl dianhydride, 2,2-bis [(3,4-dicarboxyphenoxy) phenyl] propane Anhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, and the like can be given. These aromatic tetracarboxylic dianhydrides can be used alone or in combination of two or more.

When patterning the photosensitive resin composition of the present invention with i-line, use an aromatic tetracarboxylic dianhydride having good i-line permeability such as 4,4′-oxydiphthalic dianhydride. Is preferred. Moreover, when using for the use which requires higher heat resistance, aromatic tetracarboxylic dianhydride which has rigid structures, such as a pyromellitic dianhydride, is preferable.
In addition to the aromatic tetracarboxylic dianhydride used as the main raw material, an aliphatic tetracarboxylic dianhydride can also be used. Specific examples include, for example, butane-1,2,3,4-tetracarboxylic dianhydride, pentane-1,2,4,5-tetracarboxylic dianhydride, cyclobutane tetracarboxylic dianhydride. , Cyclopentane-1,2,3,4-tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, cyclohex-1-ene-2,3,5,6- Tetracarboxylic dianhydride, 3-ethylcyclohex-1-ene-3- (1,2), 5,6-tetracarboxylic dianhydride, 1-methyl-3-ethylcyclohexane-3- (1, 2), 5,6-tetracarboxylic dianhydride, 1-methyl-3-ethylcyclohex-1-ene-3- (1,2), 5,6-tetracarboxylic dianhydride, 1-ethyl Cyclohexane-1- (1,2), 3,4 Tetracarboxylic dianhydride, 1-propylcyclohexane-1- (2,3), 3,4-tetracarboxylic dianhydride, 1,3-dipropylcyclohexane-1- (2,3), 3- ( 2,3) -tetracarboxylic dianhydride, dicyclohexyl-3,4,3 ′, 4′-tetracarboxylic dianhydride, bicyclo [2.2.1] heptane-2,3,5,6-tetra Carboxylic dianhydride, bicyclo [2.2.2] octane-2,3,5,6-tetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene-2,3,5 , 6-tetracarboxylic dianhydride, 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, and the like. These aliphatic tetracarboxylic dianhydrides can be used alone or in combination of two or more.

In the block polyamic acid ester, the amount of the X group derived from the aliphatic tetracarboxylic dianhydride is 0 to 30 mol% with respect to the amount of the X group derived from all the tetracarboxylic dianhydrides in the block 1. It is preferably within the range, more preferably within the range of 0 to 10 mol%, and most preferably 0 mol%. When the amount of the X group derived from the aliphatic tetracarboxylic dianhydride is more than 30 mol%, the heat resistance of the cured polyimide resin may be lowered.
In the block polyamic acid ester, R in the unit unit 1 and R ′ group in the unit unit 2 are derived from alcohols used in the esterification reaction of the tetracarboxylic dianhydride. In order to impart photosensitivity, the alcohol preferably uses an alcohol having an olefinic double bond as a main component.
Specifically, 2-methacryloyloxyethyl alcohol, 2-acryloyloxyethyl alcohol, 1-acryloyloxy-2-propyl alcohol, 2-methacrylamide ethyl alcohol, 2-acrylamidoethyl alcohol, methylol vinyl ketone, 2-hydroxyethyl Examples include vinyl ketone, 2-hydroxyethyl methacrylate, glycerol monomethacrylate, and glycerol monoacrylate. These alcohols having an olefinic double bond can be used alone or in combination of two or more.

Examples of the alcohol having an olefinic double bond include polyethylene glycol monomethacrylate, polyethylene glycol monoacrylate, polyethylene glycol polypropylene glycol monomethacrylate, polyethylene glycol polypropylene glycol monoacrylate, and poly (ethylene glycol-tetramethylene glycol) mono. Long chain polyalkylene glycol acrylates such as acrylates can also be used.
Furthermore, alcohols having two or more olefinic double bonds in the molecule can also be suitably used for synthesizing the block polyamic acid ester. Specifically, glycerol dimethacrylate, glycerol diacrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, and the like can be given.
Further, as disclosed in JP-A-06-080776, an olefinic double bond such as methyl alcohol, ethyl alcohol, n-propyl alcohol, or isopropyl alcohol is added to the alcohol having an olefinic double bond. You may mix and use alcohols which do not have a coupling | bonding.

In the block polyamic acid ester, the amount of R groups derived from alcohols having no olefinic double bond is in the range of 0 to 30 mol% with respect to the amount of R groups derived from all alcohols in block 1. It is preferably within the range, more preferably within the range of 0 to 10 mol%, and most preferably 0 mol%. When the amount of the R group derived from the alcohol having no olefinic double bond is more than 30 mol%, the lithography performance may be deteriorated. For the same reason, the amount of R ′ group derived from alcohols having no olefinic double bond is also in the range of 0 to 30 mol% with respect to the amount of R ′ group derived from alcohols in block 2. It is preferably within the range, more preferably within the range of 0 to 10 mol%, and most preferably 0 mol%.
Stoichiometrically, the amount of alcohol used for esterification of tetracarboxylic dianhydride is 1.00 equivalent (monovalent) per 1.00 equivalent (0.50 mol) of tetracarboxylic dianhydride. However, when synthesizing a block polyamic acid ester, 1.01 to 1.10 equivalents of alcohol is used per 1.00 equivalent of tetracarboxylic dianhydride. The synthesis of a carboxylic acid diester is preferable because the storage stability of the finally obtained photosensitive resin composition is improved.

Next, the Y group in the unit unit 1 will be described.
The Y group is a divalent organic group having 4 to 30 carbon atoms and is derived from diamines used as raw materials. As the diamine, aromatic diamines are preferably mainly used. In Block 1, by introducing an aromatic group into the diamine together with the tetracarboxylic dianhydride described above, the heat resistance of the cured polyimide resin film is improved. Can be increased.
Specific examples of aromatic diamines include paraphenylene diamine, metaphenylene diamine, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfide, 4,4′-diaminobenzophenone, 3,4′-. Diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfone, 3,3′-diaminodiphenyl sulfone, 4,4′-diaminodiphenyl sulfoxide, 3,3′-dimethyl-4,4′-diaminobiphenyl, 2,2 '-Dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl, 1,4-bis (4- Aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) ) Benzene, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, 4,4′-bis (4-aminophenoxy) biphenyl, 4,4′- Bis (3-aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) phenyl] ether, 1,4-bis (4-aminophenyl) benzene, 9,10-bis (4-aminophenyl) anthracene, 1 1,1,1,3,3,3-hexafluoro-2,2-bis (4-aminophenyl) propane, 1,1,1,3,3,3-hexafluoro-2,2-bis [4- (4-Aminophenoxy) phenyl] propane, 1,1,1,3,3,3-hexafluoro-2,2-bis (3-amino-4-methylphenyl) propane, 1,4-bis ( 3-aminopropyldimethylsilyl) benzene or a part of the hydrogen atoms directly bonded to the aromatic ring of these aromatic diamines is substituted with a group selected from the group consisting of a methyl group, an ethyl group, and a halogen group. Etc.

Among these, more preferred aromatic diamines have two non-condensed benzene rings such as 4,4′-diaminodiphenyl ether or 3,3′-dimethyl-4,4′-diaminobiphenyl. And aromatic diamines. A photosensitive resin composition containing a block polyamic acid ester using such aromatic diamines has improved temporal stability. Any of the above aromatic diamines can be used alone or in admixture of two or more.
When patterning the photosensitive resin composition of the present invention with i-line, it is preferable to use an aromatic diamine having good i-line permeability such as bis (4- (4-aminophenoxy) phenyl) sulfone. .
The Y ′ group in the unit unit 2 is derived from diamines used as raw materials, as in the case of the Y group. The diamine is preferably a diamine having a group selected from the group consisting of a divalent organic group having 4 to 30 carbon atoms and a divalent silicon-containing group having 2 to 50 silicon atoms. Examples of the divalent organic group having 4 to 30 carbon atoms include aliphatic diamines having an acyclic structure (hereinafter simply referred to as aliphatic diamines) or diamines having an alicyclic structure (hereinafter simply referred to as fats). Cyclic diamines) can be preferably used.

  Specific examples of the aliphatic diamines include ethylene glycol diamines such as bis (aminomethyl) ether, bis (2-aminoethyl) ether, bis (3-aminopropyl) ether, and bis (2-aminomethoxy) ethyl. ] Ether, bis [2- (2-aminoethoxy) ethyl] ether, bis [2- (3-aminoprotoxy) ethyl] ether, 1,2-bis (aminomethoxy) ethane, 1,2-bis (2 -Aminoethoxy) ethane, 1,2-bis [2- (aminomethoxy) ethoxy] ethane, 1,2-bis [2- (2-aminoethoxy) ethoxy] ethane, ethylene glycol bis (3-aminopropyl) ether , Diethylene glycol bis (3-aminopropyl) ether, triethylene glycol bis (3-aminopropyl) Ether, methylenediamine, ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diamino Examples include octane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane and the like. These aliphatic diamines may be used alone or in combination of two or more.

  Specific examples of the alicyclic diamines include, for example, isophorone diamine, 4,4′-diaminodicyclohexylmethane, 1,8-diamino-p-menthane, 1,4-cyclohexanebis (methylamine), 1,3- Cyclohexanebis (methylamine), 2,5-diaminomethyl-bicyclo [2,2,2] octane, 2,5-diaminomethyl-7,7-dimethylbicyclo [2,2,1] heptane, 2,5- Diaminomethyl-7,7-difluorobicyclo [2,2,1] heptane, 2,5-diaminomethyl-7,7,8,8-tetrafluorobicyclo [2,2,2] octane, 2,5-diamino Methyl-7,7-bis (hexafluoromethyl) bicyclo [2,2,1] heptane, 2,5-diaminomethyl-7-oxabicyclo [2,2,1] hepta 2,5-diaminomethyl-7-thiabicyclo [2,2,1] heptane, 2,5-diaminomethyl-7-oxobicyclo [2,2,1] heptane, 2,5-diaminomethyl-7-azabicyclo [2,2,1] heptane, 2,6-diaminomethyl-bicyclo [2,2,2] octane, 2,6-diaminomethyl-7,7-dimethylbicyclo [2,2,1] heptane, 2, 6-diaminomethyl-7,7-difluorobicyclo [2,2,1] heptane, 2,6-diaminomethyl-7,7,8,8-tetrafluorobicyclo [2,2,2] octane, 2,6 -Diaminomethyl-7,7-bis (hexafluoromethyl) bicyclo [2,2,1] heptane, 2,6-diaminomethyl-7-oxybicyclo [2,2,1] heptane, 2,6-diaminomethyl 7-thiobicyclo [2,2,1] heptane, 2,6-diaminomethyl-7-oxobicyclo [2,2,1] heptane, 2,6-diaminomethyl-7-iminobicyclo [2,2,1] Heptane, 2,5-diamino-bicyclo [2,2,1] heptane, 2,5-diamino-bicyclo [2,2,2] octane, 2,5-diamino-7,7-dimethylbicyclo [2,2 , 1] heptane, 2,5-diamino-7,7-difluorobicyclo [2,2,1] heptane, 2,5-diamino-7,7,8,8-tetrafluorobicyclo [2,2,2] Octane, 2,5-diamino-7,7-bis (hexafluoromethyl) bicyclo [2,2,1] heptane, 2,5-diamino-7-oxabicyclo [2,2,1] heptane, 2,5 -Diamino-7-thiabicyclo [2,2,1] heptane, 2,5-diamino-7-oxobicyclo [2,2,1] heptane, 2,5-diamino-7-azabicyclo [2,2,1] heptane, 2,6- Diamino-bicyclo [2,2,1] heptane, 2,6-diamino-bicyclo [2,2,2] octane, 2,6-diamino-7,7-dimethylbicyclo [2,2,1] heptane, 2 , 6-Diamino-7,7-difluorobicyclo [2,2,1] heptane, 2,6-diamino-7,7,8,8-tetrafluorobicyclo [2,2,2] octane, 2,6- Diamino-7,7-bis (hexafluoromethyl) bicyclo [2,2,1] heptane, 2,6-diamino-7-oxybicyclo [2,2,1] heptane, 2,6-diamino-7-thiobicyclo [2,2,1] heptane, 2,6 Diamino-7-oxobicyclo [2,2,1] heptane, 2,6-diamino-7-iminobicyclo [2,2,1] heptane, 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1, 4-diaminocyclohexane, 1,2-di (2-aminoethyl) cyclohexane, 1,3-di (2-aminoethyl) cyclohexane, 1,4-di (2-aminoethyl) cyclohexane, bis (4-aminocyclohexyl) ) Methane, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraoxaspiro [5,5] undecane, bicyclo [2,2,1] heptanebismethylamine and the following formula What is done. These alicyclic diamines may be used alone or in combination of two or more.

（式中、Ｒ₁およびＲ₄は二価の炭化水素基を示し、それぞれ同一でも異なっていてもよく、Ｒ₂およびＲ₃は一価の炭化水素基を示し、それぞれ同一でも異なっていてもよく、ｐは１以上の整数を表す。） As the diamine having a divalent silicon-containing group having 2 to 50 silicon atoms (hereinafter simply referred to as silicon-containing diamine), for example, a diamino (poly) siloxane represented by the following formula can be preferably used. .

(Wherein R ₁ and R ₄ represent a divalent hydrocarbon group, which may be the same or different, and R ₂ and R ₃ represent a monovalent hydrocarbon group, which may be the same or different, respectively. Well, p represents an integer of 1 or more.)

Preferred examples of R ₁ and R ₄ include a methylene group, an ethylene group, a propylene group, a butylene group, and a phenylene group. Preferred examples of R ₂ and R ₃ include a methyl group, an ethyl group, a propyl group, a butyl group, and a phenyl group.
In Block 2, by introducing any of the above-mentioned aliphatic diamines, alicyclic diamines, or silicon-containing diamines as diamines, reducing E of the cured polyimide resin film Can do. Moreover, about these diamines, all can be used individually or in mixture of 2 or more types. In these diamines, it is more preferable to contain at least silicon-containing diamines from the viewpoint of improving adhesion to the substrate.
In the block polyamic acid ester, the repeating number of the unit unit 1 in the block 1 and the repeating number of the unit unit 2 in the block 2 is an average per molecule, and the preferable range of the unit unit 1 is 1.1 to 500. More preferably, it is 1.1-300, Most preferably, it is 1.2-200. The preferable range of the unit unit 2 is 1.1 to 300, more preferably 1.1 to 200, and most preferably 1.2 to 100. When the value of the unit unit 1 exceeds 500, and when the value of the unit unit 2 exceeds 300, the solubility of the block polyamic acid ester in the photosensitive resin composition is not preferable.

The ratio defined by the value obtained by dividing the number of repeating unit units 1 in block 1 by the number of repeating unit units 2 in block 2 (hereinafter referred to as unit ratio) depends on the type and molecular weight of the raw materials used. 0.5-50 are preferable, 1-20 are more preferable, and 3-10 are the most preferable. If the above unit ratio value is smaller than 0.5, the proportion of the block 2 having a low Tg is too high, and the heat resistance of the cured polyimide resin film becomes too low. The ratio of 1 is too large to reduce the residual stress. From the viewpoint of heat resistance, the Tg derived from the block 1 is more preferably in the region B ′ at 200 to 380 ° C., and more preferably in the region B ″ at 240 to 380 ° C.
The number average molecular weight of the block polyamic acid ester is preferably 3000 to 100,000, more preferably 3000 to 50000. When the molecular weight is less than 3000, the heat resistance and strength are not preferred, and when it is more than 100,000, the solubility in a solvent is not preferred.

As described above, the Tg in the region B of the cured polyimide resin film is controlled by controlling the constituent units of each block constituting the block polyamic acid ester, the number of repetitions thereof, and the molecular weight of the entire block polyamic acid ester. Thus, the physical property that cannot be achieved by the conventionally known photosensitive polyimide technology is achieved, in which E can be remarkably reduced while maintaining high.
That is, when the photosensitive resin composition of the present invention is used, it has a high-temperature Tg of 150 ° C. to 380 ° C. as heat resistance that can withstand the actual manufacturing process of a semiconductor device, and 2 GPa when E is suitable. The following polyimide resin film can be obtained. In a more preferred embodiment, when Tg is 240 to 380 ° C. and E is suitably, a polyimide resin film lower than 2 GPa can be obtained. In the polyimide resin film obtained by curing the photosensitive resin composition of the present invention, the Tg on the low temperature side at −150 to 0 ° C. is not more than room temperature, so that the heat resistance required in the actual semiconductor device manufacturing process is required. Does not affect sex.
Thus, although the polyimide resin film obtained by heat-curing the photosensitive resin composition of the present invention maintains a high Tg in the region B, the reason for developing a low E is not clear, but the polyimide resin film It is presumed that the portion derived from block 1 and the portion derived from block 2 were microphase-separated and functional separation of each block was highly achieved. This is suggested by the fact that the resin film is composed of two block structures, and a clear Tg peak is observed in each of the regions A and B due to the single structure of each block.

Next, a method for synthesizing the block polyamic acid ester will be described.
When the block polyamic acid ester is composed of two blocks, block 1 and block 2, for example, the polyamic acid ester corresponding to each block is prepared separately by the method shown in Patent Document 3 described above. The block polyamic acid ester can be obtained by mixing them and subjecting them to a condensation reaction. Here, in order that both blocks can be subjected to a condensation reaction, when the terminal group of one polyamic acid ester is a carboxylic acid, the terminal group of the other polyamic acid ester is an amino group. It is necessary to adjust the molar ratio of tetracarboxylic dianhydride and diamine. In this method, it is possible to synthesize a blocky polyamic acid ester having a more preferable complete block property. Here, having a complete block property means that the block 1 is composed only of the unit unit 1 and the block 2 is composed only of the unit unit 2 except for a small amount of impurities derived from unreacted substances.

On the other hand, tetracarboxylic dianhydride, which is a constituent raw material, is common between block 1 and block 2, and aromatic diamines are used as raw materials for block 1, and aliphatic diamines having higher reactivity as raw materials for block 2 In some cases, a synthesis method utilizing the reactivity difference between the two diamines may be possible. For example, a block polyamic acid ester can be produced by simultaneously adding an aromatic diamine and an aliphatic diamine to a previously prepared tetracarboxylic acid diester and subjecting it to a condensation reaction. In this method, it is not possible to synthesize a blocky polyamic acid ester having complete blocking properties, but it is possible to synthesize a blocky polyamic acid ester having blocking properties. Here, having the block property means that the block 1 mainly includes the unit unit 1 and the block 2 mainly includes the unit unit 2.
As described above, the block polyamic acid ester which is a component of the photosensitive resin composition of the present invention is a polyimide resin film obtained by heat curing, and Tg is recognized in the high temperature region B and the low temperature region A, respectively. What is necessary is just to have the block property of a grade, and it does not make it a prerequisite to have perfect block property. Further, if Tg is not recognized in the region C between the region A and the region B, units other than the block 1 and the block 2 may be contained.

(B) Photopolymerization initiator Although the photosensitive resin composition of the present invention has photosensitivity derived from the double bond of the block polyamic acid ester, the photosensitivity can be further improved by adding a photopolymerization initiator. It is preferable to improve.
Specific examples of the photopolymerization initiator include, for example, benzophenone, methyl O-benzoylbenzoate, 4-benzoyl-4′-methyldiphenylketone, dibenzylketone, benzophenone derivatives such as fluorenone, 2,2′-diethoxyacetophenone, Acetophenone derivatives such as 2-hydroxy-2-methylpropiophenone, 1-hydroxycyclohexyl phenyl ketone, thioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, thioxanthone derivatives such as diethylthioxanthone, benzyl, benzyldimethyl ketal, benzyl-β -Benzyl derivatives such as methoxyethyl acetal, benzoin derivatives such as benzoin methyl ether, 2,6-di (4'-diazidobenzal) -4-methylcyclohexanone, 2,6'-di Azides such as 4′-diazidobenzal) cyclohexanone, 1-phenyl-1,2-butanedione-2- (O-methoxycarbonyl) oxime, 1-phenylpropanedione-2- (O-methoxycarbonyl) oxime, 1-phenyl Propanedione-2- (O-ethoxycarbonyl) oxime, 1-phenylpropanedione-2- (O-benzoyl) oxime, 1,3-diphenylpropanetrione-2- (O-ethoxycarbonyl) oxime, 1-phenyl- Oximes such as 3-ethoxypropanetrione-2- (O-benzoyl) oxime, N-arylglycines such as N-phenylglycine, peroxides such as benzoyl peroxide, aromatic bisimidazoles, titanocenes, etc. Oximes are preferred in terms of photosensitivity. Arbitrariness. As for the addition amount of these photoinitiators, 1-20 mass parts is preferable with respect to 100 mass parts of block polyamic acid ester.

(C) Solvent In the composition of the present invention, it is preferable to adjust the viscosity by adding a solvent as described below, since there is no undissolved material in the composition and the composition becomes homogeneous. As a result, the coating film after application and after curing becomes homogeneous and has excellent surface smoothness.
As the solvent, it is more preferable to use an organic solvent (hereinafter referred to as a good solvent) having good solubility in either block 1 or block 2 of the block polyamic acid ester or both.
Preferred examples of a good solvent for block 1 (hereinafter referred to as solvent 1) include N, N-dimethylformamide, N-methylpyrrolidone (hereinafter also referred to as NMP), N-ethyl-2-pyrrolidone, and N, N. -Dimethylacetamide, diethylene glycol dimethyl ether, cyclopentanone, γ-butyrolactone, α-acetyl-γ-butyrolactone, tetramethylurea, 1,3-dimethyl-2-imidazolinone, N-cyclohexyl-2-pyrrolidone, etc. These can be used alone or in combination of two or more.

（式中、Ｒ₁は２価の有機基であり、Ｒ₂、Ｒ₃、及びＲ₄は、それぞれ独立して１価の有機基、及びハロゲン基からなる群から選ばれる基である。） As a good solvent for the block 2 (hereinafter referred to as solvent 2), a solvent having a specific structure represented by the following general formula (2) is preferable.

(Wherein R ₁ is a divalent organic group, and R ₂ , R ₃ , and R ₄ are each independently a group selected from the group consisting of a monovalent organic group and a halogen group.)

  Specifically, benzyl alcohol, benzhydrol, 3-chlorobenzyl alcohol, 4-chlorobenzyl alcohol, 2-chlorobenzyl alcohol, 3,4-dimethoxybenzyl alcohol, 4-fluorobenzyl alcohol, 2-methoxybenzyl alcohol, 3-methoxybenzyl alcohol, 2-nitrobenzyl alcohol, phenethyl alcohol, phenoxyethanol, N-phenyldiethanolamine, α, β-dihydroxyethylbenzene, 2-phenyl-propanol-2, 3,4,5-trimethoxybenzyl alcohol, cinnamon Alcohol, 1-phenyl-1-propanol, 4-methylbenzyl alcohol, 2- (N-ethyl-m-toluidino) ethanol, triphenylmethanol, 4-methoxybenzyl alcohol , 3-phenyl-1-propanol, N-hydroxyethylaniline, 2-fluorobenzyl alcohol, β-ethylphenethyl alcohol, 1-naphthalenemethanol, 3-iodobenzyl alcohol, 2-methylphenethyl alcohol, 3-methylphenethyl Alcohol, 4-methylbenzyl alcohol, 3-methylbenzyl alcohol, 3,4-dimethylbenzyl alcohol, 2,5-dimethylbenzyl alcohol, 2-methylbenzhydrol, 4-ethoxybenzyl alcohol, 2-ethoxybenzyl alcohol, 3 -(N-benzyl-N-methylamino) -1,2-propanediol, ethyl DL-mandelate, 1-phenoxy-2-propanol, 1- (4-methylphenyl) ethanol, α, β-dihydroxyethylben 1,2-dihydroxy-3-phenoxypropane, α-hydroxyethylbenzene, 1,3-bis (hexafluoro-2-hydroxyisopropyl) benzene, 2- (benzyloxy) ethanol, N-ethyl-N- (2 -Hydroxyethyl) aniline, ethyl-2-hydroxy-4-phenylbutyrate, 3- (2-methoxyphenoxy) -1,2-propanediol, p-methoxyphenethyl alcohol, 2-hydroxybutyl-p-tosylate and the like. These can be used alone or in combination of two or more.

The solvent 2 is preferably an organic solvent having a boiling point in the range of 150 to 300 ° C. When the boiling point is in this range, when the polyamic acid ester of the present invention is converted to a polyimide resin by heating by a method as described later, the solvent remains in the coating film appropriately, and phase separation of the block 2 portion results. It is preferable because devitrification of the coating does not occur.
The above solvent 2 has particularly good solubility in the block 2, so that a homogeneous composition can be obtained as described above, combined with the effect of high boiling point, the coating film after coating and curing becomes homogeneous, and the surface smoothness It will be excellent.
Other preferred examples of the solvent 2 include lactic acid esters such as ethyl lactate and butyl lactate, propylene glycol monoalkyl ethers, 2-hydroxyisobutyric acid esters, methyl benzoate, ethyl benzoate, propyl benzoate, and benzoic acid. Hydrocarbons such as butyl, benzyl benzoate, diethylbenzene, diamylbenzene, triamylbenzene, amyltoluene, p-cymene, alcohols such as n-heptanol, n-octanol, n-decanol, ethylphenyl ether, n-butyl Examples thereof include ethers such as phenyl ether and ketones such as methyl-n-hexyl ketone and diisobutyl ketone.
It is preferable that the above solvent 2 is 10-100 mass% with respect to the total mass of a solvent. If the content of the solvent 2 is less than 10% by mass, the coating film may be devitrified, which is not preferable.

Moreover, a nonionic alcohol-type surfactant can be used for a solvent as an additive. Specific examples in this case include surfactants obtained by addition polymerization of an alkylene oxide to an aliphatic higher alcohol, such as polyoxyethylene lauryl ether, polyoxypropylene lauryl ether, polyoxyethylene oleyl ether, polyoxypropylene oleyl. Ether, polyoxyethylene cetyl ether, polyoxypropylene cetyl ether, polyoxyethylene stearyl ether, polyoxypropylene stearyl ether and the like are included.
Furthermore, a block copolymer type surfactant is also suitable. Specifically, binary block copolymers such as polyethylene glycol polypropylene glycol and polyethylene glycol polybutylene glycol, and linear chains such as polyethylene glycol polypropylene glycol polyethylene glycol, polypropylene glycol polyethylene glycol polypropylene glycol, and polyethylene glycol polybutylene glycol polyethylene glycol. And polyether block copolymers such as ternary block copolymers.

Furthermore, as a branched block copolymer, a structure in which at least three hydroxyl groups contained in sugar chains typified by glycerol, erythritol, pentaerythritol, pentitol, pentose, hexitol, hexose, heptose and the like are combined with a polymer chain And / or a structure in which at least three of hydroxyl groups and carboxyl groups contained in hydroxyl acid are bonded to the block copolymer chain. Specifically, a compound in which a polyethylene glycol polypropylene glycol block copolymer is bonded to three hydroxyl groups of glycerol, a compound in which polyethylene glycol polypropylene glycol polyethylene glycol polypropylene glycol block copolymer is bonded to three or four hydroxyl groups of erythritol are included. .
Specific examples of the sugar chain used to obtain the above branched block copolymer include sorbitol, mannitol, xylitol, threitol, maltitol, arabitol, lactitol, adonitol, cellobiitol, glucose, fructose, sucrose, lactose, Mannose, galactose, erythrose, xylulose, allulose, ribose, sorbose, xylose, arabinose, isomaltose, dextrose, glucoheptose and the like can be mentioned.

Specific examples of hydroxyl acid include citric acid, malic acid, tartaric acid, gluconic acid, glucuronic acid, glucoheptonic acid, glucooctanoic acid, threonic acid, saccharic acid, galactonic acid, galactaric acid, galacturonic acid, glyceric acid. And hydroxysuccinic acid.
These solvents (including the above-mentioned solvent additives) can be appropriately added to the photosensitive resin composition of the present invention not only for obtaining a uniform composition but also depending on the coating film thickness and viscosity. However, it is preferable to use in the range of 30-600 mass parts with respect to 100 mass parts of block polyamic acid ester.
Furthermore, in order to improve the storage stability over time of the photosensitive resin composition of the present invention, in addition to the solvent 1 and / or the solvent 2, the following specific alcohols are used as the solvent. can do.

Specific examples of the specific alcohol include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, t-butyl alcohol, ethyl lactate, butyl lactate, propylene glycol-1 -Methyl ether, propylene glycol-2-methyl ether, propylene glycol-1-ethyl ether, propylene glycol-2-ethyl ether, propylene glycol-1- (n-propyl) ether, propylene glycol-2- (n-propyl) Ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, monoalcohols such as ethylene glycol-n-propyl ether, dia, such as ethylene glycol and propylene glycol Mention may be made of the call class. Among these, ethyl lactate, butyl lactate, propylene glycol-1-methyl ether, propylene glycol-1-ethyl ether, and propylene glycol-1- (n-propyl) ether are more preferable. Of these, those having a boiling point in the range of 150 to 300 ° C. also have the effect as the solvent 2 described above.
The content of the specific alcohol in the solvent is preferably 0.1 to 80% by mass, more preferably 10 to 70% by mass. When the content of the specific alcohol is less than 0.1% by mass, the storage stability of the photosensitive resin composition is deteriorated. For example, when the composition is allowed to stand for 2 weeks at room temperature, Precipitates may be observed inside. Moreover, when it exceeds 80 mass%, the solubility of block property polyamic acid ester will worsen.

(D) Other components In order to further improve the photosensitivity, a compound having a reactive carbon-carbon double bond that does not correspond to the component (a) can be added to the photosensitive resin composition of the present invention. . Such compounds include 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, ethylene glycol diacrylate, polyethylene glycol diacrylate (2-20 moles of ethylene monomer units), pentaerythritol diacrylate, dipenta Examples include erythritol hexaacrylate, tetramethylolmethane tetraacrylate, methylenebisacrylamide, N-methylolacrylamide, and compounds obtained by substituting the above acrylate or acrylamide with methacrylate or methacrylamide. The compound having such a reactive carbon-carbon double bond is preferably added in an amount of 1 to 90 parts by mass with respect to 100 parts by mass of the block polyamic acid ester.

A sensitizer can be added to the photosensitive resin composition of the present invention in order to further improve the photosensitivity. Examples of the sensitizer include Michler's ketone, 4,4′-bis (diethylamino) benzophenone, 2,5-bis (4′-diethylaminobenzal) cyclopentane, and 2,6-bis (4′-diethylaminobenzal) cyclohexanone. 2,6-bis (4′-diethylaminobenzal) -4-methylcyclohexanone, 4,4′-bis (dimethylamino) chalcone, 4,4′-bis (diethylamino) chalcone, p-dimethylaminocinnamylidene Indanone, p-dimethylaminobenzylidene indanone, 2- (p-dimethylaminophenylbiphenylene) -benzothiazole, 2- (p-dimethylaminophenylvinylene) benzothiazole, 2- (p-dimethylaminophenylvinylene) isonaphth Thiazole, 1,3-bis (4′-dimethylamino) Nobenzal) acetone, 1,3-bis (4′-diethylaminobenzal) acetone, 3,3′-carbonyl-bis (7-diethylaminocoumarin), 3-acetyl-7-dimethylaminocoumarin, 3-ethoxycarbonyl-7 -Dimethylaminocoumarin, 3-benzyloxycarbonyl-7-dimethylaminocoumarin, 3-methoxycarbonyl-7-diethylaminocoumarin, 3-ethoxycarbonyl-7-diethylaminocoumarin, N-phenyl-N'-ethylethanolamine, N- Phenyldiethanolamine, Np-tolyldiethanolamine, N-phenylethanolamine, 4-morpholinobenzophenone, isoamyl dimethylaminobenzoate, isoamyl diethylaminobenzoate, 2-mercaptobenzimidazole, 1-pheny -5-mercaptotetrazole, 2-mercaptobenzothiazole, 2- (p-dimethylaminostyryl) benzoxazole, 2- (p-dimethylaminostyryl) benzthiazole, 2- (p-dimethylaminostyryl) naphtho (1,2 -D) thiazole, 2- (p-dimethylaminobenzoyl) styrene and the like.
From the viewpoint of sensitivity, it is preferable to use a combination of a sensitizer having a mercapto group and a sensitizer having a dialkylaminophenyl group. These can be used alone or in combination of 2 to 5 kinds. The sensitizer for improving the photosensitivity is preferably used in an amount of 0.1 to 50 parts by mass with respect to 100 parts by mass of the block polyamic acid ester.

  In addition, an adhesion aid can be added to the photosensitive resin composition of the present invention in order to improve the adhesion to the substrate. Adhesion aids include γ-aminopropyldimethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, 3- Methacryloxypropyldimethoxymethylsilane, 3-methacryloxypropyltrimethoxysilane, dimethoxymethyl-3-piperidinopropylsilane, diethoxy-3-glycidoxypropylmethylsilane, N- (3-diethoxymethylsilylpropyl) succinimide N- [3- (triethoxysilyl) propyl] phthalimidic acid, benzophenone-3,3′-bis (N- [3-triethoxysilyl] propylamide) -4,4′-dicarboxylic acid, benzene-1, 4-bis (N- [3-trie Silane coupling agents such as (toxisilyl) propylamide) -2,5-dicarboxylic acid, and aluminum-based adhesion assistants such as aluminum tris (ethyl acetoacetate), aluminum tris (acetylacetonate), ethyl acetoacetate aluminum diisopropylate Etc. In these, it is more preferable to use a silane coupling agent from the point of adhesive force. The addition amount of the adhesion assistant is preferably in the range of 0.5 to 50 parts by mass with respect to 100 parts by mass of the block polyamic acid ester.

In addition, a thermal polymerization inhibitor can be added to the photosensitive resin composition of the present invention in order to improve the viscosity of the composition solution during storage and the stability of photosensitivity. Examples of thermal polymerization inhibitors include hydroquinone, N-nitrosodiphenylamine, p-tert-butylcatechol, phenothiazine, N-phenylnaphthylamine, ethylenediaminetetraacetic acid, 1,2-cyclohexanediaminetetraacetic acid, glycol etherdiaminetetraacetic acid, 2,6 -Di-tert-butyl-p-methylphenol, 5-nitroso-8-hydroxyquinoline, 1-nitroso-2-naphthol, 2-nitroso-1-naphthol, 2-nitroso-5- (N-ethyl-N- Sulfopropylamino) phenol, N-nitroso-N-phenylhydroxylamine ammonium salt, N-nitroso-N- (1-naphthyl) hydroxylamine ammonium salt and the like are used. The amount of the thermal polymerization inhibitor is preferably in the range of 0.005 to 30 parts by mass with respect to 100 parts by mass of the block polyamic acid ester.
The photosensitive resin composition of the present invention can be obtained by mixing the above-described components in any order. Moreover, components other than the block polyamic acid ester may be dissolved in a solvent in advance, and then the block polyamic acid ester may be dissolved.

(E) Method for forming cured relief pattern As one aspect of a method for forming a cured relief pattern comprising a polyimide resin from the photosensitive resin composition of the present invention, the following steps are preferred.
(I) A coating film formed on the substrate is obtained by applying the photosensitive resin composition to the substrate and drying;
(Ii) The coating film is exposed to ultraviolet rays through a photomask having a pattern or directly, and then treated with a solvent to remove unexposed portions of the coating film, thereby Forming a polyamic acid ester pattern on the material;
(iii) The polyamic acid ester pattern is heated to imidize the polyamic acid ester in the pattern, thereby forming a cured relief pattern made of a polyimide resin on the substrate.
Examples of the substrate that can be used in the method for forming a cured relief pattern of the present invention include a silicon wafer, a metal, glass, a semiconductor, a metal oxide insulating film, and silicon nitride. A silicon wafer is preferably used. The thickness of the substrate is preferably 200 μm to 800 μm, but is not limited thereto.

As a method for coating the photosensitive resin composition of the present invention on a substrate, methods conventionally used for coating a photosensitive resin composition, for example, spin coater, bar coater, blade coater, curtain coater, screen, etc. A method of applying with a printing machine or the like, a method of spraying with a spray coater, or the like can be used.
As a method for drying the coating film, methods such as air drying, heat drying with an oven or hot plate, and vacuum drying are used. Moreover, it is desirable that the coating film be dried under conditions such that imidation of the block polyamic acid ester in the composition does not occur. Specifically, when air drying or heat drying is performed, it is preferably performed at 20 ° C. to 140 ° C. for 1 minute to 1 hour.
The coating film thus obtained is subjected to pattern exposure with an ultraviolet light source or the like using an exposure apparatus such as a contact aligner, mirror projection, or stepper, and then developed.

The developer used for development is preferably a good solvent for the polyimide precursor or a combination of a good solvent and a poor solvent. The selection of the good solvent and the poor solvent is affected by the chemical structure of the block unit in the block polyamic acid ester, the length of each block unit, the molecular weight of the ester, and the like.
Preferable good solvents include N-methylpyrrolidone, N-cyclohexyl-2-pyrrolidone, N, N-dimethylacetamide, cyclopentanone, cyclohexanone, γ-butyrolactone, α-acetyl-γ-butyrolactone, and the like. As the poor solvent, toluene, xylene, methanol, ethanol, isopropyl alcohol, ethyl lactate, propylene glycol methyl ether acetate, water and the like are preferable. When a good solvent and a poor solvent are mixed and used, the ratio of the poor solvent to the good solvent is adjusted depending on the solubility of the polymer. Moreover, several types of solvents can be used in combination.

As a method used for development, an arbitrary method can be selected and used from conventionally known photoresist development methods such as a rotary spray method, a paddle method, and an immersion method involving ultrasonic treatment.
By heating the relief pattern of the polyamic acid ester obtained as described above and dispersing and imidizing the photopolymerized group having an olefinic double bond, a cured relief pattern made of a polyimide resin is obtained. Convert. Various methods such as a method using a hot plate, a method using an oven, and a method using a temperature rising oven capable of setting a temperature program can be selected as a method for heat conversion. Heating can be performed at 280 ° C. to 450 ° C. for 30 minutes to 5 hours. Air may be used as the atmospheric gas for heat conversion, and an inert gas such as nitrogen or argon may be used.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.
The properties of the polyamic acid ester or the coating film were measured and evaluated according to the following method.
(1) Measurement of number average molecular weight (Mn) of polyamic acid ester The number average molecular weight (Mn) of the polyamic acid ester was measured by a gel permeation chromatography method (standard polystyrene conversion).
(2) Measurement of glass transition temperature (Tg) of polyimide coating film On a 5-inch silicon wafer (produced by Fujimi Electronics Co., Ltd., Japan) having a thickness of 625 μm ± 25 μm as a substrate, the film thickness after curing is about 10 μm. After the photosensitive resin composition was spin-coated so as to be, a heat-cured polyimide coating film was obtained by heating at 350 ° C. for 2 hours in a nitrogen atmosphere. The obtained polyimide coating film was peeled from the silicon wafer using hydrofluoric acid to obtain a polyimide tape.
The obtained polyimide tape was measured for a temperature distribution curve of Tanδ with a dynamic viscoelasticity measuring device (ORIENTEC, RHEOVIBRON MODEL RHEO-1021) in the range of −150 to 400 ° C., and obtained as the temperature at which the peak appeared. . Here, the load was 3 g, the frequency was 110 Hz, and the heating rate was 4 ° C./min.
Here, the peak means that Tan δ has a maximum value, the difference between the maximum value and the value of Tan δ at a temperature 20 ° C. higher than the temperature at which the maximum value is shown, and the temperature at which the maximum value and the maximum value are at 20 ° C. The value with the larger difference from the value of Tan δ at low temperature is 0.005 or more.

(3) Measurement of Young Modulus (E) of Polyimide Coating Film E of a polyimide tape obtained in the same manner as in the above (2) was measured according to ASTM-D-882-88.
(4) Measurement of residual stress of polyimide coating film Photosensitive on a 5-inch silicon wafer (made by Fujimi Electronics Co., Ltd., Japan) having a thickness of 625 μm ± 25 μm as a substrate so that the film thickness after curing is about 10 μm. After spin-coating the conductive resin composition, a thermally cured polyimide coating film was obtained by heating at 350 ° C. for 2 hours in a nitrogen atmosphere. The obtained polyimide coating film was measured at 25 ° C. with a stress measuring device (Model FLX-2320, manufactured by Tencor).

(5) Relief patterning of polyimide and evaluation of resolution The photosensitive resin composition was spin-coated on a 5-inch silicon wafer and dried to form a 10 μm thick coating film. This coating film was irradiated with energy of 300 mJ / cm ² by a g-line stepper NSR1505g2 (manufactured by Nikon Corporation, Japan) using a reticle with a test pattern. Subsequently, the coating film formed on the wafer is spray-developed with a developing machine (D-SPIN636 type, manufactured by Dainippon Screen Mfg. Co., Ltd.) using cyclopentanone, rinsed with propylene glycol methyl ether acetate, and polyamide A relief pattern comprising an acid ester was obtained.
The wafer on which the relief pattern was formed was heat-treated in a nitrogen atmosphere at 200 ° C. for 1 hour and subsequently at 350 ° C. for 2 hours using a temperature rising programmed curing furnace (VF-2000 type, manufactured by Koyo Lindberg, Japan). As a result, a cured relief pattern made of polyimide resin having a thickness of 5 μm was obtained on the silicon wafer.
About the obtained hardening relief pattern, the pattern shape and the width | variety of the pattern part were observed under the optical microscope, and the resolution was calculated | required. Regarding the resolution, a pattern having a plurality of openings with different areas is formed by exposure through a reticle with a test pattern in the same manner as described above, and the area of the resulting polyimide resin pattern openings corresponds to the resolution. If the pattern reticle opening area is ½ or more, it is regarded as resolved, and the length of the opening side of the reticle corresponding to the resolved opening having the smallest area is defined as the resolution. A resolution of 10 μm or less was considered good.
(6) Evaluation of surface smoothness Photosensitive resin composition on a 5-inch silicon wafer (manufactured by Fujimi Electronics Co., Ltd., Japan) having a thickness of 625 μm ± 25 μm as a substrate so that the film thickness after curing is about 10 μm. After spin-coating the product, it was heated at 350 ° C. for 2 hours under a nitrogen atmosphere to obtain a thermally cured polyimide coating film. Surface smoothness was determined to be good if the film thickness after curing was measured at any 30 locations on the surface of the coating film using Nanospec, model 5100 manufactured by Nanometrics, and the standard deviation was within 200 nm. .

<Synthesis Example 1> (Synthesis of blocky polyamic acid ester)
Pyromellitic dianhydride (PMDA) (112.4 g) was put in a 2 liter separable flask, 2-hydroxyethyl methacrylate (HEMA) (136.8 g) and γ-butyrolactone (400 ml) were added and stirred at room temperature. While adding 81.5 g of pyridine, a reaction mixture was obtained. After completion of the exothermic reaction, the mixture was allowed to cool to room temperature and left for 16 hours. Next, under ice cooling, a solution obtained by dissolving 210.4 g of dicyclohexylcarbodiimide (DCC) in 180 ml of γ-butyrolactone was added to the reaction mixture over 40 minutes with stirring. This reaction solution was added to a 5 liter separable flask in which 112.6 g of 4,4′-diaminodiphenyl ether (DADPE) was suspended in 200 ml of γ-butyrolactone with stirring under ice cooling over 60 minutes ( Reaction solution 1).

  Next, 28.22 g of pyromellitic dianhydride (PMDA) was placed in a 2 liter separable flask, 35.9 g of 2-hydroxyethyl methacrylate (HEMA) and 100 ml of γ-butyrolactone were added and stirred at room temperature. While stirring, 21.0 g of pyridine was added to obtain a reaction mixture. After completion of the exothermic reaction, the mixture was allowed to cool to room temperature and left for 16 hours. Next, under ice cooling, a solution obtained by dissolving 54.8 g of dicyclohexylcarbodiimide (DCC) in 60 ml of γ-butyrolactone was added to the reaction mixture over 40 minutes with stirring. Subsequently, α, ω- with a number average molecular weight of 1000 was added. A solution prepared by dissolving 78.1 g of aminopropylpolydimethylsiloxane (manufactured by Chisso Corporation, Silaplane, FM3311) in 312 ml of γ-butyrolactone and 78 ml of butyl benzoate was added over 60 minutes while stirring (reaction liquid 2).

  The reaction solution 2 was added to the reaction solution 1 over 60 minutes with stirring under ice-cooling, and further stirred at room temperature for 4 hours. Then, 240 ml of ethyl alcohol was added and stirred for 1 hour, and then 7000 ml of γ-butyrolactone. Was added. The precipitate generated in the reaction mixture was removed by filtration to obtain a reaction solution. The obtained reaction solution was added to 10 liters of ethyl alcohol to produce a precipitate consisting of a crude polymer. The produced crude polymer was separated by filtration and dissolved in 1.5 liter of tetrahydrofuran to obtain a crude polymer solution. The crude polymer solution was dropped into 28 liters of water to precipitate the polymer, and the resulting precipitate was filtered off and dried under vacuum to obtain a powdered polymer (polyamic acid ester A). It was 20000 when the number average molecular weight (Mn) of the polyamic acid ester was measured by gel permeation chromatography (standard polystyrene conversion).

<Example 1>
Using the obtained polyamic acid ester A, a polyamic acid ester composition was prepared by the following method, and the physical properties of the prepared composition were measured and evaluated. Polyamic acid ester A 100 g, diphenylpropanetrione-2- (O-ethoxycarbonyl) oxime 4 g, tetraethylene glycol dimethacrylate 4 g, 1-phenyl-5-mercaptotetrazole 2 g, N-phenyldiethanolamine 4 g, N- [3- (tri Ethoxysilyl) propyl] phthalamic acid 3 g and 2-nitroso-1-naphthol 0.02 g were dissolved in a solvent consisting of 70 g of NMP and 80 g of benzyl alcohol. The viscosity of the obtained solution was adjusted to about 3 Pa · s by adding a small amount of NMP and benzyl alcohol while maintaining the quantitative ratio of NMP and benzyl alcohol to obtain a photosensitive resin composition.
Next, polyimide resin films for residual stress measurement and resolution measurement were formed by the methods described above.
The resolution and surface smoothness of the obtained resin film were good, and Tg was recognized at −90 ° C. and 330 ° C., but not between them. E was as low as 1.7 GPa and the residual stress was as low as 20.3 MPa.

<Example 2>
A photosensitive resin composition was obtained in the same manner as in Example 1 except that the benzyl alcohol in Example 1 was changed to phenoxyethanol. Next, polyimide resin films for residual stress measurement and resolution measurement were formed by the methods described above.
The resolution and surface smoothness of the obtained resin film were good, and Tg was observed at −85 ° C. and 330 ° C., but not between them. E was as low as 1.7 GPa and the residual stress was sufficiently low at 20.5 MPa.
<Example 3>
A photosensitive resin composition was prepared in the same manner as in Example 1 except that only NMP was used instead of benzyl alcohol in Example 1, and a polyimide resin film was further formed. Glass transition temperatures were found at -88 ° C and 328 ° C, E was 1.8 GPa and residual stress was sufficiently low at 21 MPa, but foreign matter was scattered in the thin film, and the surface smoothness was sufficiently satisfactory. It wasn't.

<Comparative Example 1>
Pyromellitic dianhydride (PMDA) 140.6g was put in a 5 liter separable flask, 172.7g of 2-hydroxyethyl methacrylate (HEMA) and γ-butyrolactone 500ml were stirred at room temperature and stirred. While adding 102.5 g of pyridine, a reaction mixture was obtained. After completion of the exothermic reaction, the mixture was allowed to cool to room temperature and left for 16 hours. Next, under ice cooling, a solution prepared by dissolving 265.2 g of dicyclohexylcarbodiimide (DCC) in 240 ml of γ-butyrolactone was added to the reaction mixture over 40 minutes with stirring. This reaction solution was charged with 107.4 g of 4,4′-diaminodiphenyl ether (DADPE) and 62.0 g of α, ω-aminopropylpolydimethylsiloxane (manufactured by Chisso Corporation, Silaplane, FM3311) having a number average molecular weight of 1000. The solution suspended in 512 ml of butyrolactone was added over 60 minutes with stirring under ice cooling. After further stirring at room temperature for 4 hours, 240 ml of ethyl alcohol was added and stirred for 1 hour, and then 700 ml of γ-butyrolactone was added.

The precipitate generated in the reaction mixture was removed by filtration to obtain a reaction solution. The obtained reaction solution was added to 10 liters of ethyl alcohol to produce a precipitate consisting of a crude polymer. The produced crude polymer was separated by filtration and dissolved in 1.5 liter of tetrahydrofuran to obtain a crude polymer solution. The crude polymer solution was dropped into 28 liters of water to precipitate the polymer, and the resulting precipitate was filtered off and dried under vacuum to obtain a powdered polymer (polyamic acid ester B). It was 20000 when the number average molecular weight (Mn) of the polyamic acid ester B was measured by gel permeation chromatography (standard polystyrene conversion).
Next, a photosensitive resin composition was obtained in the same manner as in Example 1. The obtained photosensitive composition was an opaque liquid. Next, polyimide resin films for residual stress measurement and resolution measurement were formed by the methods described above. The surface of the obtained resin film was not smooth and devitrified. Tg is observed not only at −110 ° C. and 330 ° C. but also at 208 ° C., which is not suitable as a polyimide film for semiconductors. E was 2.1 GPa and the residual stress was 24 MPa.

  The polyimide resin film obtained by heat-curing the photosensitive resin composition of the present invention can be suitably used in the field of materials such as semiconductor surface protective films, interlayer insulating films, and multichip modules.

Claims (4)

(A) At least a block 1 consisting of m unit units 1 (amidate ester) obtained by condensing X carboxylic acid and Y amine represented by the following general formula (1), and X ′ carboxylic acid and Y ′ amine are condensed. A polyimide resin film, which is a polyamic acid ester having a number average molecular weight of 3,000 to 100,000, comprising a block 2 composed of n unit units 2 (amidate ester), Each of the region A of 150 to 0 ° C. and the region B of 150 to 380 ° C. has at least one glass transition temperature obtained from a temperature dispersion curve obtained by a dynamic viscoelasticity measurement method. Region C between region B includes 100 parts by weight of a polyamic acid ester having no glass transition temperature, (b) 1 to 20 parts by weight of a photopolymerization initiator, and (c) 30 to 600 parts by weight of a solvent. The photosensitive resin composition characterized by.

(In the formula, X and X ′ are each independently a tetravalent organic group having 6 to 32 carbon atoms, Y is a divalent organic group having 4 to 30 carbon atoms, and Y ′ is the number of carbon atoms. A group selected from the group consisting of a divalent organic group having 4 to 30 and a divalent silicon-containing group having 2 to 50 silicon atoms, wherein R and R ′ each independently have an olefinic double bond 1 Valent group.) The photosensitive resin composition according to claim 1, wherein the solvent is a solvent containing 10 to 100% by mass of a solvent represented by the following general formula (2).

(Wherein R ₁ is a divalent organic group, and R ₂ , R ₃ , and R ₄ are each independently a group selected from the group consisting of a monovalent organic group and a halogen group.)   The photosensitive resin composition according to claim 1 or 2, wherein the solvent is a solvent containing 10 to 100% by mass of an organic solvent having a boiling point at 150 to 300 ° C.   The process of forming the coating film on this base material by apply | coating to the base material the photosensitive resin composition in any one of Claims 1-3, and drying, via the photomask which has a pattern, or directly A step of irradiating the coating film with ultraviolet light, a step of developing an unexposed portion of the coating film by developing with a developing solution to form a relief pattern on the substrate, and heating the relief pattern A method for forming a cured relief pattern comprising the steps of: forming a cured relief pattern comprising a polyimide resin on the substrate.