JPH11209613A - Photosensitive polyimide precursor composition and production of pattern by using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition which has excellent photosensitive characteristics and can therefore form a good pattern even in a low exposure by including a polyimide precursor containing photosensitive groups with a photoinitiator comprising a coumarin compound and a hexaarylbisimidazole compound in a specified ratio. SOLUTION: There is provided a composition comprising 100 pts.wt. polyimide precursor having photosensitive groups and comprising repeating units represented by formula I; a photoinitiator comprising 0.01-5 pts.wt. coumarin compound represented by formula II such as 7-N,N-ethylamino-4-methylcoumarin and 0.1-10 pts.wt. hexaarylbisimidazole compound represented by formula III; 0.1-15 pts.wt. arylglycine compound such as N-phenylglycine; and 5-50 pts.wt. addition-polymerizable compound. In the formula, R<1> is a tetravalent organic group; R<2> is a tri- or tetra-valent organic group containing an aromatic ring; A is an acidic monovalent group, and n is 1 or 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive material suitable for a protective film such as a surface coat film of a semiconductor element and an interlayer insulating film of a thin-film multilayer wiring board, and more particularly to a photosensitive material containing a heat-resistant polyimide precursor, The present invention also relates to a negative photosensitive polyimide precursor composition that can be developed with a basic aqueous solution as well as a method for producing a pattern.

[0002]

2. Description of the Related Art Conventionally, as a photosensitive heat-resistant material for obtaining a heat-resistant polymer, an aromatic tetracarboxylic dianhydride described in JP-B-5-67026 is reacted with an olefinically unsaturated alcohol. To synthesize an olefin aromatic tetracarboxylic acid diester, and polymerize the compound and a diamine by a dehydration condensation reaction using carbodiimide to introduce a photosensitive group through a covalent bond, and JP-B-63-31939. It is known that an aromatic tetracarboxylic dianhydride described above is reacted with an aromatic diamine compound to introduce a photosensitive group by ionic bonding.

In each of these prior arts, a varnish dissolved in an appropriate organic solvent is applied to a substrate, dried to form a film, and then irradiated with ultraviolet rays through an appropriate photomask to expose the exposed portion to light. By curing, developing and rinsing with an organic solvent, a negative relief pattern is obtained.

In addition to these materials, as a material that can be developed with an aqueous liquid, for example, a positive polymer in which a naphthoquinonediazidosulfonylamide group is introduced into a carboxyl group of a polyamic acid has been proposed (Japanese Patent Laid-Open No. 6-1994). 2
No. 58835). This polymer has a feature that the naphthoquinonediazidosulfonylamide group is changed to a carboxyl group by light irradiation, so that the exposed portion is solubilized in a basic aqueous solution, and is used as a positive photosensitive material. However, at present, such a positive photosensitive polyimide precursor composition has not been obtained which has high sensitivity, excellent pattern shape, and performance for practical use.

However, these photosensitive polyimide precursors use an aromatic monomer having excellent heat resistance and mechanical properties as a basic skeleton, and have low light transmittance in the ultraviolet region due to absorption of the polyimide precursor itself. In addition, the photochemical reaction in the exposed portion cannot be performed sufficiently effectively, resulting in a problem that the sensitivity is low or the pattern shape is deteriorated. In recent years, with the increasing integration of semiconductors, processing rules have become increasingly smaller, and higher resolutions have been required.

For this reason, a conventional contact / proximity exposure machine using parallel rays has been replaced by a 1: 1 projection exposure machine called a mirror projection and a reduction projection exposure machine called a stepper. The stepper utilizes a monochromatic light such as an excimer laser and a high-power oscillation line of an ultra-high pressure mercury lamp. Until now, g-line steppers using visible light (wavelength: 435 nm) called g-line of an ultra-high pressure mercury lamp have been the mainstream stepper. However, in order to respond to the demand for finer processing rules, a stepper to be used is used. Needs to be shortened. Therefore, the exposure equipment used is from a g-line stepper (wavelength: 435 nm) to an i-line stepper (wavelength: 3).
65 nm).

However, as described above, a photosensitive polyimide base polymer generally has low transparency, and particularly has little transmittance at i-line (wavelength: 365 nm).
Even if an i-line stepper is used, it is very difficult to obtain a proper pattern. In addition, a polyimide film for surface protection is required to be a thicker film corresponding to LOC (lead-on-chip), which is a high-density mounting method of a semiconductor element. The problem gets worse. Therefore, there is a strong demand for a photosensitive polyimide which has sufficient sensitivity even at the bottom where the illuminance by the i-line stepper is extremely low and which can obtain a good pattern shape. This is the same for the negative photosensitive polyimide precursor composition.

Therefore, a photoinitiator having high sensitivity and excellent internal curability is required. Hexaarylbisimidazole compounds have been used as a highly sensitive initiator. For example, JP-A-61-123603 discloses a high-sensitivity photoinitiator system using a 3-keto-substituted coumarin compound and a heterocyclic thiol compound in addition to hexaarylbisimidazole. A photoinitiator system using 3,3'-carbonylbis (7-diethylamino) coumarin as a photosensitizer in a recording material is disclosed. Such a 3-keto-substituted coumarin compound is a compound having good intersystem crossing to a triplet and is known as an effective sensitizer in various photoinitiator systems.
However, in the photosensitive polyimide precursor composition,
Even if these conventional compounds were used, no effect was observed, and no satisfactory sensitivity could be obtained in any case.

In Japanese Patent Application Laid-Open No. Hei 8-297367,
A benzoxazolyl group, a benzothiazolyl group, and a benzimidazolyl group are introduced as a substituent at the 3-position to achieve high sensitivity. However, these compounds have a longer absorption wavelength by a 3-position substituent so as to absorb at 400 nm or more, which is a laser wavelength, and are suitable for photocuring using i-line which is becoming mainstream. Not.

[0010]

SUMMARY OF THE INVENTION It is a first object of the present invention to provide a photosensitive polyimide precursor composition having excellent photosensitive characteristics and capable of obtaining a good pattern having an excellent shape even at a low exposure dose. It is. It is still another object of the present invention to provide a photosensitive polyimide precursor resin composition that can be developed not only with an organic solvent but also with an alkaline aqueous solution. A second object of the present invention is to provide a method for producing a polyimide pattern exhibiting excellent heat resistance and chemical resistance.

The present invention relates to (A) a polyimide precursor having a photosensitive group, (B) a coumarin compound represented by the general formula (I),

Embedded image(Where R¹¹And R¹²Are each independently a hydrogen atom or an alkyl
And R represents¹³And R ¹⁴Are each independently a hydrogen atom or
A ring having 4 to 22 carbon atoms which represents or is bonded to an alkyl group
And (b2) represented by the general formula (II)
Hexaarylbisimidazole compounds,

Embedded image (Where X is an alkyl group, a halogen atom, a trihalomethyl group, a nitro group, an alkoxy group, or COR ′, CO
The present invention relates to a photosensitive polyimide precursor composition containing OR ″ (R ′ and R ″ represent a substituent represented by an alkyl group).

Further, the present invention provides a polyimide precursor having a photosensitive group represented by the following general formula (III):

Embedded image (Where R ¹ is a tetravalent organic group, R ² is a trivalent or tetravalent organic group containing an aromatic ring, and two R ³ are each independently a monovalent organic group having a photosensitive group. , A is an acidic monovalent group, and n is 1 or 2.) The photosensitive polyimide precursor composition has a repeating unit represented by the following formula:

Further, the present invention provides the above-mentioned photosensitive composition, comprising 0.01 to 5 parts by weight of the component (b1) and 0.1 to 10 parts by weight of the component (b2) based on 100 parts by weight of the component (A). The present invention relates to a polyimide precursor composition.

The present invention further comprises (b3) an aromatic mercapto compound having a heterocycle or an arylglycine compound and (C) an ethylenically unsaturated compound having a boiling point of 100 ° C. or more at normal pressure. The photosensitive polyimide precursor composition described above.

Further, the present invention provides a step of forming a film using the above photosensitive polyimide precursor composition, a step of irradiating the film with light through a mask having a predetermined pattern, and a step of irradiating the film with the light. And a method for developing a pattern using an organic solvent or a basic aqueous solution.

[0016]

DETAILED DESCRIPTION OF THE INVENTION The polyimide precursor having a photosensitive group used in the photosensitive polyimide precursor composition of the present invention is generally a polyamide having a structural unit formed from a tetracarboxylic acid residue and a diamine residue. An acid or a derivative thereof. A photosensitive group is a group that is eliminated by light irradiation,
These are groups that can be dimerized or copolymerized by light irradiation. The photosensitive group may be bonded to a tetracarboxylic acid residue, or may be bonded to a diamine residue. The photosensitive group is
It may be introduced via a covalent bond such as an ester bond or an amide bond, or may be introduced via an ionic bond. As the photosensitive group, a group containing a carbon-carbon unsaturated double bond is preferable since good photosensitivity can be imparted, and a group having an acryloyl group or a methacryloyl group is more preferable. The polyimide precursor having a photosensitive group is preferably a polyimide precursor having a photosensitive group and an acidic group, since it can be easily developed with a basic aqueous solution. Among these, the photosensitive polyimide precursor used in the present invention exhibits good photosensitive properties and developability in a basic aqueous solution, so that a photosensitive group is covalently bonded to a tetracarboxylic acid residue and a diamine residue. A polyimide precursor in which an acidic group is covalently bonded is preferable, and specifically, the above-mentioned general formula (II)
Those having the structural unit represented by I) are more preferable because they are easy to produce and have particularly excellent photosensitive characteristics when used in combination with the component (B). In the structural unit represented by the general formula (III), the tetravalent organic group represented by R ¹ is a residue of a tetracarboxylic acid or a derivative thereof capable of reacting with a diamine to form a polyimide precursor. It is preferably a tetravalent organic group having 4 or more carbon atoms from the viewpoint of mechanical properties, heat resistance and adhesiveness of the polyimide film obtained by curing. Preferred examples thereof are shown in the following structural formula group. Among tetravalent organic groups having 4 or more carbon atoms, a total of 6 carbon atoms including an aromatic ring (benzene ring, naphthalene ring, etc.)
More preferably, it is an organic group of from 30 to 30. Further, it is preferable that the binding sites of the four carboxyl groups of the tetracarboxylic acid consist of two pairs of two binding sites at the ortho or peri position of the aromatic ring. In the polyimide precursor molecule, in the plurality of repeating units, all R ¹ are
They may be the same or different.

Embedded image

In the general formula (III), the group exhibiting acidity, that is, the group represented by A is a sulfonic acid group (--SO
₃ H), sulfinic acid group (-SO ₂ H), carboxyl group (-COO
It is preferable to use either H) or a phenolic hydroxyl group because of good solubility, and a carboxyl group and a phenolic hydroxyl group are more preferable because the synthesis of the polyimide precursor is easy. In the polyimide precursor molecule, all of the A
May be the same or different. General formula (I
In II), the group R ² to which the acidic group A is bonded is preferably a diamine residue capable of forming a polyimide precursor by reacting with a tetracarboxylic acid or a derivative thereof, and is preferably a polyimide film obtained by curing. From the viewpoint of mechanical properties, heat resistance and adhesiveness, an organic group containing an aromatic ring is preferable, and from the viewpoint of mechanical properties, heat resistance and adhesiveness of a polyimide film obtained by curing, containing an aromatic ring. Total carbon number 6
More preferably, it is an organic group of from 30 to 30. Specific preferred examples are shown in the following structural formula groups. In the polyimide precursor molecule, in the plurality of repeating units, all R ² may be the same or different.

Embedded image

In the general formula (III), the monovalent organic group having a photosensitive group represented by R ³ is preferably a group having a polymerizable carbon-carbon unsaturated double bond. General formula

Embedded image (However, R ⁴ , R ^5, and R ⁶ are each independently selected from hydrogen, an alkyl group, a phenyl group, a vinyl group, and a propenyl group, and R ⁷ represents a divalent organic group.) The organic group to be used is preferable because it can impart high-sensitivity photosensitivity. The alkyl group preferably has 1 to 4 carbon atoms. The divalent organic group represented by R ⁷ is preferably an alkylene group having 1 to 20 carbon atoms such as a methylene group, an ethylene group, and a propylene group. In particular, a methacryloyloxyalkyl group and an acryloyloxyalkyl group (having an alkyl group having 1 to 20 carbon atoms) are suitable for the present invention because they not only realize high sensitivity but also are easy to synthesize. The polyimide precursor used in the present invention,
It may contain a repeating unit other than the repeating unit represented by the general formula (III), which is represented by the general formula (III)
A unit having no group corresponding to A in the repeating unit represented by
A unit in which R ^{3 of the} repeating unit represented by the general formula (III) is a hydrogen atom or an organic group containing no photosensitive group. As the repeating unit having no group corresponding to A of the repeating unit represented by the general formula (III), a repeating unit represented by the general formula (III)
And the group corresponding to R ² includes the following repeating units.

Embedded image

Embedded image

Embedded image

In the polyimide precursor of the present invention, the proportion of the repeating unit represented by the general formula (III) is preferably 10 to 100 mol% in terms of mol percentage of all the repeating units. It is preferable because it is excellent in balance between developability and a good pattern shape, and more preferably 80 to 100 mol%. The molecular weight of the polyimide precursor in the present invention is 10,000 to 200, in terms of weight average molecular weight, from the viewpoint of cured film properties after imidization.
000 is preferable, and 20,000 to 80,000 is more preferable. The weight average molecular weight can be measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene. The polyimide precursor used in the present invention is prepared by mixing and reacting a tetracarboxylic dianhydride and a hydroxy group-containing compound to produce a half ester of tetracarboxylic acid, and then acid chloride with thionyl chloride, followed by reaction with a diamine. And a method of reacting the tetracarboxylic acid half ester with a diamine using a carbodiimide as a condensing agent. As the tetracarboxylic dianhydride, for example, oxydiphthalic acid, pyromellitic acid,
3,3 ', 4,4'-benzophenonetetracarboxylic acid, 3,3', 4,4'-biphenyltetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid,
2,3,6,7-naphthalenetetracarboxylic acid, 1,
4,5,8-naphthalenetetracarboxylic acid, 2,3
5,6-pyridinetetracarboxylic acid, 3,4,9,10
-Perylene tetracarboxylic acid, sulfonyl diphthalic acid,
m-terphenyl-3,3 ', 4,4'-tetracarboxylic acid, p-terphenyl-3,3', 4,4'-tetracarboxylic acid, 1,1,1,3,3,3- Hexafluoro-2,2-bis (2,3- or 3,4-dicarboxyphenyl) propane, 2,2-bis (2,3- or 3,4
-Dicarboxyphenyl) propane, 2,2-bis {4 '-(2,3- or 3,4-dicarboxyphenoxy) phenyl} propane, 1,1,1,3,3,3-hexafluoro-2 , 2-bis {4 '-(2,3- or 3,4-dicarboxyphenoxy) phenyl} propane, having the following general formula (IV)

Embedded image (Wherein, R ¹¹ and R ¹² each represent a monovalent hydrocarbon group, and may be the same or different, and s is an integer of 1 or more). Examples include tetracarboxylic dianhydrides such as acids, which are used alone or in combination of two or more. Examples of the diamine to give a general formula (III) a diamine residue R ² in the structural unit represented by the 3,5-diaminobenzoic acid, 4,4'-dihydroxy-3,3'-diamino biphenyl, 3,4-diamino Benzoic acid, 3,
3'-dihydroxy-4,4'-diaminobiphenyl,
2,3-diamino-4-hydroxypyridine, 2,2-
Bis (4-hydroxy-3-aminophenyl) hexafluoropropane, 2,4-diaminophenol, 2,4
-Diaminobenzoic acid, 3-carboxy-4,4'-diaminodiphenylether, 3,3'-dicarboxy-
4,4'-diaminodiphenyl ether, 3-carboxy-4,4'-diaminodiphenylmethane, 3,3'-
Dicarboxy-4,4'-diaminodiphenylmethane,
3,3′-dicarboxy-4,4′-diaminobiphenyl, 3,3 ′, 5,5′-tetracarboxy-4,4 ′
-Diaminobiphenyl, 3-carboxy-4,4'-diaminodiphenylsulfone, 3,3'-dicarboxy-
4,4′-diaminodiphenyl sulfone, 1,1,1,
3,3,3-hexafluoro-2,2-bis (3-carboxy-4-aminophenyl) propane and the like. As the diamine providing a diamine residue other than the structural unit represented by the general formula (III), 4,4 ′-(or 3,
4'-, 3,3'-, 2,4'-, 2,2'-) diaminodiphenyl ether, 4,4'- (or 3,4'-,
3,3 '-, 2,4'-, 2,2 '-) diaminodiphenylmethane, 4,4'- (or 3,4'-, 3,3 '
-, 2,4 '-, 2,2'-) diaminodiphenylsulfone, 4,4'- (or 3,4'-, 3,3'-, 2,
4 '-, 2,2'-) diaminodiphenyl sulfide,
Paraphenylenediamine, metaphenylenediamine, p
-Xylylenediamine, m-xylylenediamine, o-
Trizine, o-tolidine sulfone, 4,4'-methylene-bis- (2,6-diethylaniline), 4,4'-methylene-bis- (2,6-diisopropylaniline),
2,4-diaminomesitylene, 1,5-diaminonaphthalene, 4,4'-benzophenonediamine, bis- @ 4
-(4'-aminophenoxy) phenyl} sulfone,
1,1,1,3,3,3-hexafluoro-2,2-bis (4-aminophenyl) propane, 2,2-bis ｛4
-(4'-aminophenoxy) phenyl} propane,
3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3 ', 5,5'-tetramethyl-4,4'-
Diaminodiphenylmethane, bis {4- (3'-aminophenoxy) phenyl} sulfone, 2,2-bis (4-
Aminophenyl) propane and the like, and these are used alone or in combination of two or more. Others
The diamine residue is represented by the following general formula (V) in order to improve adhesion.

Embedded image (Wherein, R ¹³ and R ¹⁴ each represent a divalent hydrocarbon group, which may be the same or different, and R ¹⁵ and R ¹⁶ each represent a monovalent hydrocarbon group, each of which may be the same or different. Often, t is an integer of 1 or more.) It is also possible to use a diamine such as diaminopolysiloxane. R
^{Examples of 13} and R ¹⁴ include an alkylene group such as a methylene group, an ethylene group and a propylene group, an arylene group such as a phenylene group, and a bonding group thereof, and R ¹⁵ and R ¹⁶ include a methyl group, an ethyl group, and the like. And an aryl group such as a phenyl group. When these are used, it is preferable to use 1 to 30 mol% based on all amine components. Further, as a diamine, 4,4′-diaminodiphenylether-3-sulfonamide, 3,4′-diaminodiphenylether-
4-sulfonamide, 3,4'-diaminodiphenylether-3'-sulfonamide, 3,3'-diaminodiphenylether-4-sulfonamide, 4,4'-diaminodiphenylether-3-carboxamide, 3,
Use of a diamine compound having a sulfonamide group or a carboxamide group such as 4'-diaminodiphenylether-4-carboxamide, 3,4'-diaminodiphenylether-3'-carboxamide, and 3,3'-diaminodiphenylether-4-carboxamide. Can also. When these are used, 1 to all amine components
Preferably, it is used in an amount of up to 30 mol%. These diamines are used alone or in combination of two or more.

The above-mentioned polyimide precursor used in the present invention is used as a raw material for a negative photosensitive material in which exposed portions are cured. Components other than the polyimide precursor of the photosensitive polyimide precursor composition containing the polyimide precursor used in the present invention will be described below.

The photosensitive polyimide precursor composition of the present invention contains (B) a specific coumarin compound represented by the following general formula (I) as a photoinitiator system.

Embedded image(Where R¹¹And R¹²Are each independently a hydrogen atom or an alkyl
And R represents¹³And R ¹⁴Are each independently a hydrogen atom or
A ring having 4 to 22 carbon atoms which represents or is bonded to an alkyl group
Form)

The alkyl group represented by R ^{11 to} R ¹⁴ includes one having 1 carbon atom such as a methyl group, an ethyl group and a propyl group.
To 20 alkyl groups. Preferred specific examples of these coumarin compounds include the following compounds.

Embedded image

Embedded image

Embedded image The compounds represented by the formulas (C1), (C2) and (C138) are respectively 7-N, N-diethylamino-4-methylcoumarin (hereinafter referred to as C1) and 7-N, N-ethylamino-4-methyl Coumarin (hereinafter C2) and 7
—N, N-diethylaminocyclopenta [c] coumarin (hereinafter C138). The content of the coumarin compound in the composition is preferably 0.01 to 5.0 parts by weight based on 100 parts by weight of the polyimide precursor.
More preferably, the content is 0.05 to 3.0 parts by weight.

In the present invention, the following general formula (I)
It is characterized by using the hexaarylbisimidazole compound (b2) represented by I).

Embedded image (Wherein X is an alkyl group (preferably an alkyl group having 1 to 10 carbon atoms), a halogen atom, a trihalomethyl group, a nitro group, an alkoxy group, or COR ′, COOR ″).
(R ′ and R ″ are alkyl groups (preferably having 1 to 10 carbon atoms)
Examples of 2) -bis (o-fluorophenyl) -4,
4 ′, 5,5′-tetraphenylbisimidazole,
2,2'-bis (o-trifluoromethylphenyl)-
4,4 ′, 5,5′-tetraphenylbisimidazole, 2,2′-bis (o-chlorophenyl) -4,
4 ′, 5,5′-tetraphenylbisimidazole,
2,2′-bis (o-bromophenyl) -4,4 ′,
5,5′-tetraphenylbisimidazole, 2,2 ′
-Bis (o-iodophenyl) -4,4 ', 5,5'-
Tetraphenylbisimidazole, 2,2′-bis (o
-Nitrophenyl) -4,4 ', 5,5'-tetraphenylbisimidazole, 2,2'-bis (o-methoxyphenyl) -4,4', 5,5'-tetraphenylbisimidazole, 2, 2′-bis (o- (carboxymethyl) phenyl) -4,4 ′, 5,5′-tetraphenylbisimidazole, 2,2′-bis (o- (methoxycarbonyl) phenyl) -4,4 ′, 5,5′-tetraphenylbisimidazole, and the like. These are used alone or in combination of two or more. The content of the hexaarylbisimidazole compound in the composition is 0.1 to 100 parts by weight of the polyimide precursor.
10.0 parts by weight, preferably 0.3 to 8.0 parts by weight.
It is more preferred to be parts by weight.

The present invention is characterized in that high sensitivity is realized by combining the above coumarin compound and hexaarylbisimidazole compound as an initiator system component, and a hydrogen donor such as an amine is added to the initiator system. By adding, it is possible to further increase the sensitivity. Particularly preferred compounds as the hydrogen donor include an aromatic mercapto compound having a heterocyclic ring and an arylglycine-based compound.

As the aromatic mercapto compound, mercaptobenzoxazole (MBO), mercaptobenzothiazole (MBT), mercaptobenzimidazole,
2,5-dimercapto-1,3,4-thiadiazole,
1-phenyl-5-mercapto-1H-tetrazole,
5-methyl-1,3,4-thiadiazole, 3-mercapto-4-methyl-4H-1,2,4-triazole and the like. On the other hand, examples of the arylglycine-based compound include N-phenylglycine (NPG), N- (p-chlorophenyl) glycine, and N- (p-bromophenyl).
Glycine, N- (p-cyanophenyl) glycine, N-
(P-methylphenyl) glycine, N-methyl-N-phenylglycine, N- (p-bromophenyl) -N-methylglycine, N- (p-chlorophenyl) -N-ethylglycine and the like. The content of the hydrogen donor in the present composition is based on 100 parts by weight of the polyimide precursor.
The amount is preferably 0.1 to 15 parts by weight, more preferably 1 to 10 parts by weight.

In the photosensitive resin composition of the present invention, it is preferable to use an addition polymerizable compound having a boiling point of 100 ° C. or more at normal pressure, since good photosensitive characteristics can be obtained. When the boiling point is lower than 100 ° C. at normal pressure, when the solvent contained in the system is removed by drying or the like or when irradiating with an actinic ray, the addition-polymerizable compound tends to be volatilized and adversely affect the properties.

Examples of the addition polymerizable compound having a boiling point of 100 ° C. or more at normal pressure include polyhydric alcohol and α, β-
A compound obtained by condensing an unsaturated carboxylic acid, for example, ethylene glycol di (meth) acrylate (meaning diacrylate or dimethacrylate, the same applies hereinafter),
Triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, 1,2-propylene glycol di (meth) acrylate, di ( 1,2
-Propylene glycol) di (meth) acrylate, tri (1,2-propylene glycol) di (meth) acrylate, tetra (1,2-propylene glycol) di (meth) acrylate, dimethylaminoethyl (meth)
Acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate,
Diethylaminopropyl (meth) acrylate, 1,4
-Butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, pentaerythritol tri (meth) acrylate, etc.), styrene, divinylbenzene, 4-vinyltoluene, 4-vinylpyridine, N-vinylpyrrolidone , 2-hydroxyethyl (meth) acrylate, 1,3- (meth) acryloyloxy-2-hydroxypropane, methylenebisacrylamide, N, N-dimethylacrylamide, N-methylolacrylamide, neopentylglycol di (meth) acrylate, Pentaerythritol di (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tetramethylolpropanetetra (meth)
Acrylates and the like are preferred, and these are used alone or in combination of two or more. When these are used, it is preferable to mix 1 to 100 parts by weight with respect to 100 parts by weight of the polyimide precursor.
It is more preferable to mix by weight, and it is even more preferable to mix 10 to 30 parts by weight.

The addition polymerizable compound is preferably soluble in the organic solvent contained in the composition of the present invention. Examples of the organic solvent include acetone, methyl ethyl ketone, diethyl ketone, toluene, chloroform, methanol, ethanol, 1-propanol, 2-propanol, 1-
Butanol, 2-butanol, t-butanol, ethylene glycol monomethyl ether, xylene, tetrahydrofuran, dioxane, cyclopentanone, N, N-
Dimethylacetamide, N, N-dimethylformamide, N-methyl-2-pyrrolidone, N-acetyl-2-
Pyrrolidone, N-benzyl-2-pyrrolidone, γ-butyrolactone, dimethylsulfoxide, ethylene carbonate, propylene carbonate, sulfolane, hexamethylenephosphortriamide, N-acetyl-ε-caprolactam, dimethylimidazolidinone, diethylene glycol dimethyl ether, triethylene glycol Dimethyl ether is a preferred example. These may be used alone or as a mixed system. The amount of the organic solvent is not particularly limited, but is preferably 100 to 300 parts by weight based on 100 parts by weight of the polyimide precursor.

The photosensitive polyimide precursor composition of the present invention may contain other additives, for example, additives such as a plasticizer and an adhesion promoter.

In the method for producing a pattern of the present invention, a polyimide film composed of a cured product of the photosensitive polyimide precursor composition of the present invention is formed by photolithography using the composition.

In the pattern manufacturing method of the present invention, first, a film made of the photosensitive polyimide precursor composition of the present invention is formed on the surface of a supporting substrate. In the pattern manufacturing method of the present invention, the surface of the support substrate may be treated in advance with an adhesion aid in order to improve the adhesion between the film or the polyimide film after heat curing and the support substrate.

The coating comprising the photosensitive polyimide precursor composition is formed, for example, by forming a varnish film of the photosensitive polyimide precursor composition and then drying it. The varnish film is formed by a method appropriately selected from means such as spin coating using a spinner, dipping, spray printing, and screen printing, depending on the viscosity of the varnish. The thickness of the film can be adjusted by the application conditions, the solid content concentration of the present composition, and the like. In addition, the film formed on the support is peeled off from the support to form a sheet made of the polyimide precursor composition, and the sheet is attached to the surface of the support substrate to form the film described above. May be.

Next, after irradiating the film with light (such as ultraviolet rays) through a photomask having a predetermined pattern, the unexposed portion is dissolved and removed with an organic solvent or a basic aqueous solution to form a desired relief pattern. obtain. The composition of the present invention is particularly suitable for i-line exposure. The developing step may be performed using a normal photoresist developing device. In the present invention, when a polyimide precursor having the repeating unit represented by the general formula (III) is used, a basic aqueous solution is preferable.

The resulting relief pattern is a polyimide precursor of the present invention which is usually partially imidized.
By heating this relief pattern at a temperature selected from the range of 150 ° C. to 450 ° C., a pattern made of polyimide can be obtained with high resolution. This pattern has high heat resistance and excellent mechanical properties. Therefore,
It is used as a surface protective film of a semiconductor element, an interlayer insulating film of a thin multilayer wiring board and the like.

[0035]

The present invention will be described below with reference to examples. Synthesis Example 1 Synthesis of polyimide precursor (1) Synthesis of acid chloride In a 200 ml four-necked flask, 3,3 ′, 4,4′-
Biphenyltetracarboxylic dianhydride (BPDA) 9.
42 g (0.032 mol), 8.32 g (0.064 mol) of 2-hydroxyethyl methacrylate (HEMA), 5.06 g (0.064 mol) of pyridine, 0.03 g of t-butylcatechol, N-methyl-2 When 70 ml of pyrrolidone (NMP) was added and stirred at 60 ° C., a clear solution was obtained in 2 hours. After stirring the solution at room temperature for 7 hours, the flask was cooled with ice and 9.88 g (0.083 mol) of thionyl chloride was added dropwise over 10 minutes. Thereafter, the mixture was stirred at room temperature for 1 hour to obtain a solution containing acid chloride.

(2) Synthesis of polyimide precursor (polyamic acid ester) In another 200 ml four-necked flask, 4.72 g (0.031 mol) of 3,5-diaminobenzoic acid and 5.25 g of pyridine were added.
06 g (0.064 mol), t-butyl catechol 0.
03 g, N-methyl-2-pyrrolidone (NMP) 50 m
The acid chloride solution obtained above was slowly added dropwise over 1 hour while the flask was cooled with ice and stirred (maintaining 10 ° C. or lower). Thereafter, the mixture was stirred at room temperature for 1 hour, poured into 1 liter of water, and the precipitated polymer was collected by filtration, washed twice with water, and dried under vacuum to obtain 22 g of a polyamic acid ester. The weight average molecular weight of this polyamic acid ester was measured by gel permeation chromatography (GPC) and found to be 44 in terms of polystyrene.
000.

Examples 1 to 5 and Comparative Examples 1 to 4 (1) Preparation of a polyimide precursor composition 10 g of the obtained polymer was dissolved in 16 g of γ-butyrolactone and 2 g of cyclopentanone. After blending 5 g and the photosensitive agent shown in Table 1, the mixture was filtered under pressure using a filter having a pore size of 3 μm to obtain a photosensitive polyimide precursor composition in the form of a solution.

(2) Pattern formation The photosensitive polyimide precursor composition prepared in Example 2 (1) was spin-coated on a silicon wafer and heated on a hot plate at 80 ° C. for 200 seconds to form a 10 μm thick coating. A membrane was obtained. This coating film was subjected to 40 (mJ / c) using an i-line stepper.
m ² ) steps from 40 to 360 (mJ / cm ² ), 10
0 (mJ / cm ²⁾ 100~900 in step (mJ /
cm ² ) Exposure was performed. Thereafter, immersion development was performed with a 2.38% by weight aqueous solution of tetramethylammonium hydroxide, followed by rinsing with water.

The pattern shape after development was measured and observed for each exposure dose. Table 1 shows the sensitivity and the degree of development obtained therefrom.
It was shown to. The sensitivity is determined by setting the development time (coating dissolution time × 1.5 to 2) at which the finest pattern is obtained, and observing the obtained pattern for each exposure with an optical microscope. It showed the lowest possible exposure (exposure required to obtain 80% film thickness). Further, the resolution indicates the interval between the finest line and space where the pattern was obtained at that time.

[Table 1]

The structure of the coumarin compound used in the comparative example is shown below.

Embedded image

Embedded image The compounds represented by the formulas (C314T) and (DETC) are coumarin 314T (C314T) and 7-
N, N-diethylamino-3-thenoylcoumarin (DE
TC).

Example 6 Using the patterns obtained in Examples 1 to 5, under a nitrogen atmosphere at 100 ° C. for 30 minutes, at 200 ° C. for 30 minutes,
Heating was performed at 0 ° C. for 60 minutes to obtain a polyimide pattern. A good polyimide pattern was obtained.

[0042]

The photosensitive polyimide precursor composition of the present invention is excellent in sensitivity, resolution and cured film properties. Further, according to the method for producing a pattern of the present invention, a polyimide pattern having excellent heat resistance and chemical resistance and having a good shape can be obtained.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 21/312 H01L 21/312 D 21/30 502R

Claims (5)

[Claims] (A) Before a polyimide having a photosensitive group
(B) Photoinitiator system (b1) General formula
A coumarin compound represented by the formula (I):(Where R¹¹And R¹²Are each independently a hydrogen atom or an alkyl
And R represents¹³And R ¹⁴Are each independently a hydrogen atom or
A ring having 4 to 22 carbon atoms which represents or is bonded to an alkyl group
And (b2) represented by the general formula (II)
Hexaarylbisimidazole compound,(Wherein X is an alkyl group, a halogen atom, a trihalomethyl
Group, nitro group, alkoxy group, or COR ', CO
A substituent represented by OR "(R 'and R" are alkyl groups)
The photosensitive polyimide precursor composition contains: 2. A polyimide precursor having a photosensitive group,
The following general formula (III) (Where R ¹ is a tetravalent organic group, R ² is a trivalent or tetravalent organic group containing an aromatic ring, and two R ³ are each independently a monovalent organic group having a photosensitive group. And A is an acidic monovalent group, and n is 1 or 2.) The photosensitive polyimide precursor composition according to claim 1, which has a repeating unit represented by the following formula: 3. An amount of (b) based on 100 parts by weight of the component (A)
1) 0.01 to 5 parts by weight of component, (b2) 0.1 to 1 component
The photosensitive polyimide precursor composition according to claim 1, which contains 0 parts by weight. 4. The composition according to claim 1, further comprising (b3) an aromatic mercapto compound or an arylglycine compound having a heterocyclic ring, and (C) an ethylenically unsaturated compound having a boiling point of 100 ° C. or more at normal pressure. 1, 2, or 3
The photosensitive polyimide precursor composition as described in the above. 5. A step of forming a film using the photosensitive polyimide precursor composition according to claim 1, 2, 3 or 4, irradiating the film with light through a mask having a predetermined pattern, and A method for producing a pattern, comprising a step of developing a film after irradiation with an organic solvent or a basic aqueous solution.