JPH10326011A - Photosensitive resin composition, production of polyimide pattern and production of semiconductor element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin compsn. which has excellent i line transmittability and the adhesiveness to a substrate, a process for producing polyimide patterns having high adhesiveness, dry etching resistance, good resolution and dimensional accuracy and a process for producing semiconductor elements. SOLUTION: This photosensitive resin compsn. contains a polyimide precursor which has the repeating unit expressed by formula (where X denotes a quadrivalent org. group contg. a silicon atom, Y denotes a bivalent org. group and R<1> and R<2> denote photosensitive groups) and has transparency to the extent of not hindering the curing reaction by light of a wavelength 365 nm. The coefft. of thermal expansion of the film after polyimidation is specified to <=20 ppm/ deg.C. This process for producing the compsn. consists in applying such photosensitive resin compsn. on a base material, drying the coating, exposing the coating to a pattern form and removing the unexposed parts by development to obtain relief patterns, then heating the relief patterns. The semiconductor elements are produced by forming the polyimide patterns on the base material by this process for production.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a photosensitive resin composition, a method for producing a polyimide pattern, and a method for producing a semiconductor element.

[0002]

2. Description of the Related Art In recent years, in the semiconductor industry, an organic material having excellent heat resistance, such as a polyimide resin, has been used as an interlayer insulating material, which has conventionally been formed using an inorganic material, taking advantage of its characteristics. Have been. However, formation of a circuit pattern on a semiconductor integrated circuit or a printed circuit board is complicated and diversified, such as forming a resist material on the base material surface, removing unnecessary portions by exposing and etching predetermined portions, and cleaning the substrate surface. Therefore, development of a heat-resistant photosensitive material that can use a necessary portion of a resist as an insulating material as it is even after pattern formation by exposure and development is desired.

As these materials, for example, heat-resistant photosensitive materials using photosensitive polyimide, cyclized polybutadiene or the like as a base polymer have been proposed. Particularly, photosensitive polyimide has excellent heat resistance and elimination of impurities. Has attracted particular attention because of its ease of use. As such a photosensitive polyimide, a system comprising a polyimide precursor and a dichromate (Japanese Patent Publication No. 49-17374) was first proposed, but this material has practical photosensitivity. In addition, it has advantages such as high film-forming ability, but has disadvantages such as lack of storage stability and chromium ions remaining in polyimide, and thus has not been put to practical use.

[0004] In order to avoid such a problem, for example, a method of mixing a compound having a photosensitive group with a polyimide precursor (Japanese Patent Application Laid-Open No. 54-109828) discloses a method in which a functional group and a photosensitive group in the polyimide precursor are mixed. A method of reacting with a functional group of a compound having a compound to give a photosensitive group (JP-A-56-2
No. 4343, Japanese Unexamined Patent Publication No. 60-100143)
And so on. However, these photosensitive polyimide precursors use a basic skeleton for an aromatic monomer having excellent heat resistance and mechanical properties.Because of the absorption of the polyimide precursor itself, the light transmittance in the ultraviolet region is low and the exposure is low. However, the photochemical reaction in the portion cannot be performed sufficiently effectively, resulting in a problem that the sensitivity is low and the shape of the pattern 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 apparatus using parallel rays has been replaced by a 1: 1 projection exposure apparatus called a mirror projection and a reduction projection exposure apparatus 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 ultra-high pressure mercury lamps have been the mainstream stepper. However, in order to respond to the demand for finer processing rules, the stepper used has been used. Needs to be shortened. Therefore, the exposure machine used is from a g-line stepper (wavelength: 435 nm) to an i-line stepper (wavelength: 36 nm).
5 nm).

However, conventional photosensitive polyimide base polymers designed for contact / proximity exposure machines, mirror projection projection exposure machines, and g-line steppers have low transparency due to the above-mentioned reasons, especially i-line. (Wavelength: 365 nm) because there is almost no transmittance.
With a line stepper, a decent pattern cannot be obtained. 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 having a high i-line transmittance and a polyimide pattern having a good pattern shape by an i-line stepper. As photosensitive polyimides suitable for an i-line stepper, those described in JP-A-6-342411, JP-A-8-36264, JP-A-8-234433, and the like are known.

On the other hand, the diameter of a silicon wafer serving as a substrate is
Each year, silicon wafers tend to be thinner. The thickness of the polyimide is large due to the above mounting method. Under such circumstances, there is a problem that the warpage of the silicon wafer on which the polyimide as the surface protective film is formed becomes larger than before due to the difference in thermal expansion coefficient between the polyimide and the silicon wafer. Therefore, there is a strong demand for a photosensitive polyimide having a lower thermal expansion property than conventional polyimides. Generally, low thermal expansion can be achieved by making the molecular structure rigid. However, in the case of the rigid structure, i-line is hardly transmitted, so that the photosensitive characteristics deteriorate. In addition, as the operation speed of the element increases, a signal delay proportional to the square root of the dielectric constant becomes a problem. Therefore, a photosensitive polyimide having a lower dielectric constant is strongly demanded.

[0008]

The object of the present invention is to provide a photosensitive resin composition having excellent i-line transmittance, adhesion to a substrate, and low thermal expansion after imidization. . The invention according to claim 2 provides a photosensitive resin composition having excellent i-line transmittance, adhesiveness to a substrate, low thermal expansion after imidization, and obtaining a good pattern even at a low exposure dose. To provide. The invention according to claim 3 is
An object of the present invention is to provide a photosensitive resin composition having the effects of the invention described in claim 1 and having particularly excellent adhesion to a substrate. The invention according to claim 4 has the effect of the invention according to claim 1,
Particularly, the present invention provides a photosensitive resin composition having excellent i-line transmittance. The invention described in claim 5 has the effects of the invention described in claim 1 and provides a photosensitive resin composition that is particularly excellent in low thermal expansion.

According to a sixth aspect of the present invention, a polyimide pattern having high mechanical properties, high heat resistance, low thermal expansion, low thermal stress, high adhesiveness and dry etching resistance can be obtained with good resolution and size. An object of the present invention is to provide a method for producing a polyimide pattern having accuracy and a pattern shape. According to a seventh aspect of the present invention, there is provided a method of manufacturing a semiconductor device having a polyimide pattern having the effects of the sixth aspect of the invention.

[0010]

The present invention provides a compound represented by the general formula (I):

Embedded image (Wherein, X represents a tetravalent organic group containing a silicon atom, Y represents a divalent organic group, and R ¹ and R ² represent a photosensitive group). The present invention relates to a photosensitive resin composition containing a polyimide precursor having a degree of transparency that does not hinder the curing reaction caused by light having a wavelength of 365 nm and having a coefficient of thermal expansion of 20 ppm / ° C. or less after the polyimide treatment.

The present invention also includes a polyimide precursor having a repeating unit represented by the general formula (I) and having a light transmittance of 5% or more per 10 μm of film thickness at a wavelength of 365 nm of the film. The present invention relates to a photosensitive resin composition comprising a polyimide film having a coefficient of thermal expansion of 20 ppm / ° C. or less. In the present invention, X in the general formula (I) is represented by the following formula X ¹ :

Embedded image (Wherein, R ³ and R ⁴ represent a monovalent hydrocarbon group and may be the same or different, and n is 0 or an integer of 1 or more). About things.

Further, the present invention relates to a photosensitive resin composition wherein the divalent organic group represented by Y in the general formula (I) contains a fluorine atom. Further, the present invention provides a compound represented by the following formula Y ¹ , wherein the divalent organic group represented by Y in the general formula (I) is:

Embedded image A photosensitive resin composition selected from the group consisting of:

Further, the present invention is characterized in that the photosensitive resin composition is coated on a substrate, dried, exposed in a pattern, an unexposed portion is removed by development, a relief pattern is obtained, and then heating is performed. To a method for producing a polyimide pattern. Furthermore, the present invention relates to a method for manufacturing a semiconductor device, wherein a polyimide pattern is formed on a substrate by the above-described method.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The polyimide precursor used in the photosensitive resin composition of the present invention has a repeating unit represented by the above general formula (I). The polyimide precursor of the general formula (I) is obtained by reacting a tetracarboxylic acid containing a silicon atom or a tetracarboxylic acid containing a derivative thereof with a diamine in an organic solvent used as required, and further introducing a photosensitive group. Alternatively, it can be synthesized by reacting a tetracarboxylic acid derivative into which a reactive group has been introduced in advance with a diamine in an organic solvent used as required.

[0015] X in the general formula (I) is a tetravalent organic group, is a residue of a tetracarboxylic acid or its derivative containing a silicon atom and has a group represented by the formula X ¹ Is preferable because the balance between the adhesiveness and other properties is excellent. R ³ and R ⁴ are monovalent hydrocarbon groups such as an alkyl group such as a methyl group, an ethyl group, and a propyl group;
There are aryl groups such as a phenyl group and a naphthyl group, etc., preferably having 1 to 10 carbon atoms, particularly preferably an alkyl group, and particularly preferably a methyl group.
Further, n representing the number of repetitions is preferably 0 or 1, because it is excellent in the balance between adhesiveness and other properties.

The polyimide precursor used in the present invention comprises:
In addition to X, it is preferable to have a repeating unit containing a tetravalent organic group containing no silicon atom. As the tetravalent organic group, a tetravalent aromatic group or an aliphatic group is preferable, and a tetravalent aromatic group is more preferable. From the viewpoint of the number of carbon atoms, those having 4 to 24 are preferable, and those having 6 to 12 are more preferable. The tetravalent aromatic group preferably includes an aromatic ring (a benzene ring, a naphthalene ring, etc.), and all four binding sites are formed from an aromatic ring. These binding sites are divided into two sets of two,
It is preferred that the two binding sites are located on adjacent carbons of the aromatic ring (ie, located at the ortho or peri position). The two sets may be from the same aromatic ring, or may be from separate aromatic rings linked through various bonds.

In particular, in terms of the mechanical properties of the film,

Embedded image Is preferred,

Embedded image Is more preferable,

Embedded image Are particularly preferred.

Y in the general formula (I) is a divalent organic group and is a residue of a diamine compound, and examples thereof include an aromatic group, an aliphatic group, a group containing an alicyclic ring, and a group containing a siloxane bond. In the case of a group containing an aromatic group, an aliphatic group, and an alicyclic ring, those having 6 to 18 carbon atoms are preferable, and an aromatic group having the above carbon number is more preferable. Here, the aromatic group preferably contains an aromatic ring (benzene ring, naphthalene ring, etc.), and its two bonding sites are directly from the aromatic ring. In this case, the two bonding sites are the same. Or from different aromatic rings.

In the general formula (I), R ¹ and R ² are photosensitive groups, preferably an organic group having an unsaturated double bond at a terminal through a covalent bond or an ionic bond.

Embedded image (Wherein, R ⁵ is a divalent organic group). Examples of R ⁵ include an alkylene group and an arylene group, and those having 1 to 10 carbon atoms are preferable.

In the polyimide precursor used in the present invention, the repeating unit represented by the general formula (I) has an adhesive property,
From the viewpoint of transparency, mechanical strength, etc., 1 to 8 of all repeating units
0 mol% is preferable, and 5 to 70 mol% is more preferable,
10 to 60 mol% is more preferable, and 20 to 60 mol%.
Is particularly preferred.

The polyimide precursor used in the photosensitive resin composition of the present invention may also have a light (i.
Line), and a polyimide precursor having a thermal expansion coefficient of 20 ppm / ° C. or less after the polyimide film of the photosensitive resin composition containing the precursor is obtained. is there. It is necessary that the polyimide precursor has such a degree of transparency that does not hinder the curing reaction by light (i-line) having a wavelength of 365 nm. If the above-mentioned resin having no transparency is used, a photosensitive resin composition capable of forming a good pattern cannot be obtained.

As one guideline of transparency, a polyimide precursor film having a thickness of 10 μm at a wavelength of 365 nm is used.
It is possible to use the light transmittance per unit as a reference, and the light transmittance is preferably 5% or more, more preferably 10% or more, still more preferably 20% or more, and 30% or more. % Is particularly preferable. When the transmittance is less than 5%, the i-line transmittance of the polyimide precursor itself is low, so that the photosensitive characteristics of the photosensitive resin composition are reduced, and the resolution and patternability particularly when a thick film is formed tend to be inferior. is there. When the light transmittance at a wavelength of 365 nm is 10% or more, particularly 20% or more, for example, a good pattern can be formed on a film having a thickness of 20 μm even at a low exposure dose of about 300 mJ / cm ^2. To play.

The film for measuring the light transmittance can be obtained by applying a resin solution of a polyimide precursor on a substrate such as a silicon wafer with a spin coater or the like, and drying it to remove the solvent. . The solvent removal conditions for measuring the light transmittance are preferably drying at 150 ° C. for 1 to 3 minutes. The dry film thickness in this measurement is 10 μm
However, the adjustment can be performed by adjusting the spin speed, the concentration of the polyimide precursor, and the like.

The polyimide precursor used in the present invention must be selected so that the film obtained by imidizing the photosensitive resin composition has a coefficient of thermal expansion of 20 ppm / ° C. or less. And more preferably 15 ppm / ° C. or less. For this purpose, as the polyimide precursor, it is preferable to select a polyimide precursor having a thermal expansion coefficient of 20 ppm / ° C. or less, and 18 ppm / ° C. or less. More preferably, it is more preferable to select so as to be 15 ppm / ° C. or less. When the coefficient of thermal expansion of the polyimide film obtained by imidizing the photosensitive resin composition exceeds 20 ppm / ° C., stress is generated due to the difference in the coefficient of thermal expansion from the silicon wafer, and the reliability as a semiconductor element is poor. For measuring the coefficient of thermal expansion, the imidized film is coated with a resin solution of a polyimide precursor or a photosensitive resin composition on a substrate such as a silicon wafer by a spin coater or the like, dried, and dried to remove the solvent. After removal, it can be obtained by heating to polyimide. The coefficient of thermal expansion is measured for a film that has been imidized under the same heating conditions as those for finally leaving the film on the substrate. The heating conditions are preferably from 300 to 400 ° C. for 60 to 120 minutes. The measurement of the coefficient of thermal expansion is performed using a thermophysical analyzer (Thermo Mechanical Anal
yzer, TMA).

The polyimide precursor used in the present invention has a repeating unit represented by the general formula (I), has the above light transmittance, and has the above coefficient of thermal expansion after polyimide of the photosensitive resin composition. Is not limited as long as it gives

The tetracarboxylic acid having a silicon atom, which is used as a material of the polyimide precursor in the present invention, includes:

Embedded image (Wherein R ³ , R ⁴ and n are the same as those described above), and bis (3,4-dicarboxyphenyl) dimethylsilane or dianhydride thereof is particularly preferable. And 1,3-bis (3,4-dicarboxyphenyl) tetramethylsilane or a dianhydride thereof are more preferred. Other tetracarboxylic acids, 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 and the like. These are used alone or in combination of two or more.

Among these other tetracarboxylic acids, since the light transmittance and the coefficient of thermal expansion are easily adjusted,
Oxydiphthalic acid, pyromellitic acid, 3,3 ', 4
4'-benzophenonetetracarboxylic acid and 3,3 ',
4,4'-biphenyltetracarboxylic acid is preferred, oxydiphthalic acid, pyromellitic acid and 3,3 ', 4,4
4'-biphenyltetracarboxylic acid is more preferred, and oxydiphthalic acid is particularly preferred. Examples of the derivative of tetracarboxylic acid include tetracarboxylic dianhydride, tetracarboxylic acid chloride and the like. As a reaction partner of the diamine, tetracarboxylic dianhydride is preferable from the viewpoint of reactivity and the like. The mixing ratio of the tetracarboxylic acid having a silicon atom to the other tetracarboxylic acid is preferably from 1/99 to 80/20 in terms of the former / the latter molar ratio, from the viewpoint of the balance between adhesion and other properties. / 95-
70/30 is more preferred, and 10/90 to 60/40 is even more preferred.

As the diamine, 2,2'-difluoro-4,4'-diaminobiphenyl, 2,2 ', 6,6'
-Tetrafluoro-4,4'-diaminobiphenyl,
3,3 ', 5,5'-tetrafluoro-4,4'-diaminobiphenyl, 2,2', 3,3 ', 5,5', 6
6'-octafluoro-4,4'-diaminobiphenyl, 2,2'-di (perfluoromethyl) -4,4'-
Diamines containing a fluorine atom such as diaminobiphenyl, 2,2 ', 6,6'-tetra (perfluoromethyl) -4,4'-diaminobiphenyl, 4,4'-(or 3,
4'-, 3,3'-, 2,4'- or 2,2'-)
Diaminodiphenyl ether, 4,4 '-(or 3,
4'-, 3,3'-, 2,4'- or 2,2 '
-) Diaminodiphenylmethane, 4,4'- (or 3,
4'-, 3,3'-, 2,4'- or 2,2 '
-) Diaminodiphenyl sulfone, 4,4'- (or 3,4'-, 3,3'-, 2,4'- or 2,
2'-) diaminodiphenyl sulfide, paraphenylenediamine, metaphenylenediamine, p-xylylenediamine, m-xylylenediamine, o-tolidine, 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-bis (4-aminophenyl) propane and the like, which are used alone or in combination of two or more.

Of these, the use of a diamine containing a fluorine atom is preferred because the light transmittance and the coefficient of thermal expansion are easily adjusted and the balance is excellent.
2'-difluoro-4,4'-diaminobiphenyl,
2,2 ', 6,6'-tetrafluoro-4,4'-diaminobiphenyl, 3,3', 5,5'-tetrafluoro-4,4'-diaminobiphenyl, 2,2 ', 3
3 ', 5,5', 6,6'-octafluoro-4,4 '
-Diaminobiphenyl, 2,2'-di (perfluoromethyl) -4,4'-diaminobiphenyl and 2,2 ',
6,6'-tetra (perfluoromethyl) -4,4'-
Diaminobiphenyl is more preferred, and 2,2'-difluoro-4,4'-diaminobiphenyl, 2,2 ', 6
6'-tetrafluoro-4,4'-diaminobiphenyl is particularly preferred. That is, the divalent organic group represented by Y in the general formula (I) is preferably one selected from the group represented by the formula Y ^1.

The amount of the diamine containing a fluorine atom is preferably in the range of 10 to 100 mol%, more preferably 30 to 100 mol% of the total amount of the diamine.
More preferably, it is 50 to 100 mol%. If the amount is less than 10 mol%, the transmittance tends to decrease, and the mechanical and thermal properties of the polyimide film tend to decrease.

The above-mentioned diamines may also have the following general formula (IV) for improving adhesion:

Embedded image (Wherein, R ⁶ and R ⁷ each represent a divalent hydrocarbon group and may be the same or different, and R ⁸ and R ⁹ each represent a monovalent hydrocarbon group, and may each be the same or different. Often, t is an integer of 1 or more.) It is also possible to use an aliphatic diamine such as diaminopolysiloxane. Examples of R ⁶ and R ⁷ include an alkylene group such as a methylene group, an ethylene group and a propylene group, an arylene group such as a phenylene group, a bonding group thereof, and the like. As R ⁸ and R ⁹ , a methyl group, an ethyl group And an aryl group such as a phenyl group. The groups represented by R ⁶ , R ⁷ , R ⁸ and R ⁹ preferably have a total carbon number of 1 to 10. When used in combination, these are preferably used in an amount of 20 mol% or less, more preferably 10 mol% or less, based on the total amount of the diamine compound.

In order to improve heat resistance, 4,4'-diaminodiphenyl ether-3-sulfonamide,
4'-diaminodiphenylether-4-sulfonamide, 3,4'-diaminodiphenylether-3'-sulfonamide, 3,3'-diaminodiphenylether-4-sulfonamide, 4,4'-diaminodiphenylether-3-carboxamide, 3,4'-diaminodiphenyl ether-4-carboxamide, 3,4'-diaminodiphenyl ether-3'-carboxamide,
Diamine compounds having a sulfonamide group or a carboxamide group such as 3,3'-diaminodiphenyl ether-4-carboxamide can be used alone or in combination of two or more. When used in combination, they are preferably used in an amount of not more than 20 mol% based on the total amount of the diamine compounds.
More preferably, it is used in a range of not more than mol%.

The organic solvent used for the reaction of the tetracarboxylic acid or its derivative and the diamine is preferably a polar solvent which completely dissolves the polyimide precursor to be produced, for example, N-methyl-2-pyrrolidone, N, N- Dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, tetramethylurea, hexamethylphosphoric triamide, and γ-butyrolactone are preferred.

In addition to the polar solvent, ketones, esters, lactones, ethers, halogenated hydrocarbons, hydrocarbons and the like can also be used. For example, acetone, diethyl ketone, methyl ethyl ketone, methyl Isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether,
Examples include tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, xylene and the like. These organic solvents can be used alone or
Used in combination of more than one type.

In the reaction of the tetracarboxylic acid or a derivative thereof and the diamine, it is preferable to mix both of them in an amount of 90 to 110 mol%, particularly preferably in an equimolar amount. The amount of the solvent is preferably 3 to 9 times the weight of the total amount of the tetracarboxylic acid or its derivative and the diamine. The reaction is
In the case of an acid anhydride and a diamine, the reaction is preferably performed at room temperature for 10 to 50 hours.

As a method for introducing a photosensitive group into the polyimide precursor, for example, a vinyl group is added to a side chain (for example, a carboxyl group) of the polyimide precursor by a covalent bond such as an ester bond, an amide bond or a urea bond. And acryloyl groups, methacryloyl groups, and the like, and a method of introducing a compound having an acryloyl group or a methacryloyl group having an amino group in a carboxyl group of a polyimide precursor by ionic bonding. From the viewpoint of easy volatilization of the photosensitive group at the time of ring closure of the thermal imide, ease of production of the photosensitive composition, etc., a method of introducing a compound having an amino group to the carboxylic acid group of the polyimide precursor by an ionic bond is preferable. .

Examples of compounds having an acryloyl group having an amino group or a methacryloyl group used for introducing ionic bonds include, for example, N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, N, N- Dimethylaminopropyl methacrylate, N, N-diethylaminopropyl methacrylate, N, N-dimethylaminoethyl acrylate, N, N-diethylaminoethyl acrylate,
Examples include N-dimethylaminopropyl acrylate, N, N-diethylaminopropyl acrylate, N, N-dimethylaminoethyl acrylamide, N, N-dimethylaminoethyl acrylamide and the like. These are used alone or in combination of two or more.

The amount of the compound having an acryloyl group having an amino group or the compound having a methacryloyl group may be 1 to 2 with respect to the amount of the polyimide precursor before introducing a photosensitive group.
It is preferably set to 00% by weight, more preferably 5 to 150% by weight. If the amount is less than 1% by weight, the photosensitivity tends to be inferior, and if it exceeds 200% by weight, the heat resistance and the mechanical properties of the film tend to be inferior. As described above, the polyimide precursor used in the present invention is obtained.

The polyimide precursor obtained as described above can be mixed with a photoinitiator, if necessary, to form a photosensitive resin composition. Examples of the photoinitiator include Michler's ketone, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, 2-t-butylanthraquinone, 2-ethylanthraquinone, 4,4, -bis (diethylamino) benzophenone, acetophenone, benzophenone, and thioxanthone 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenyl ketone,
2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propanone, benzyl, diphenyl disulfide, phenanthrenequinone, 2-isopropylthioxanthone, riboflavin tetrabutyrate, 2,
6-bis (p-diethylaminobenzal) -4-methyl-4-azacyclohexanone, N-ethyl-N- (p-
(Chlorophenyl) glycine, N-phenyldiethanolamine, 2- (o-ethoxycarbonyl) oxyimino-1,3-diphenylpropanedione, 1-phenyl-
2- (o-ethoxycarbonyl) oxyiminopropan-1-one, 3,3,4,4, -tetra (t-butylperoxycarbonyl) benzophenone, 3,3, -carbonylbis (7-diethylaminocoumarin), Bis (cyclopentadienyl) -bis- [2,6-difluoro-
3- (pyrid-1-yl) phenyl] titanium and the like. These are used alone or in combination of two or more.

The amount of the photoinitiator used is preferably 0.01 to 30% by weight, more preferably 0.05 to 10% by weight, based on the amount of the polyimide precursor.
If the amount is less than 0.01% by weight, the photosensitivity tends to be inferior, and if it exceeds 30% by weight, the mechanical properties of the film tend to be inferior.

Further, the photosensitive resin composition of the present invention may contain an addition polymerizable compound, if necessary. Examples of the addition polymerizable compound include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, trimethylolpropane diacrylate, and trimethylolpropane. Triacrylate, trimethylolpropane dimethacrylate, trimethylolpropane trimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol methacrylate, Pentaerythritol triacrylate, pentaerythritol tetraacrylate, Data pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, styrene, divinylbenzene, 4-vinyl toluene, 4-vinyl pyridine, N- vinylpyrrolidone, 2-
Hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 1,3-acryloyloxy-2-hydroxypropane, 1,3-methacryloyloxy-2
-Hydroxypropane, methylenebisacrylamide,
N, N-dimethylacrylamide, N-methylolacrylamide and the like can be mentioned. These are used alone or in combination of two or more.

The amount of the addition polymerizable compound used is preferably 1 to 200% by weight, more preferably 5 to 100% by weight, based on the amount of the polyimide precursor.
When the amount is less than 1% by weight, the photosensitive characteristics including solubility in a developer tend to be inferior, and when it exceeds 200% by weight, the mechanical characteristics of the film tend to be inferior.

The photosensitive resin composition of the present invention may contain an azide compound, if necessary.

As the azide compound, for example,

Embedded image

Embedded image And the like. These are used alone or in combination of two or more.

The amount of the azide compound to be used is preferably 0.01 to 30% by weight, more preferably 0.05 to 10% by weight, based on the amount of the polyimide precursor. If the amount is less than 0.01% by weight, the photosensitivity tends to be poor, and if it exceeds 30% by weight, the mechanical properties of the film tend to be inferior.

Further, the photosensitive resin composition of the present invention may contain a radical polymerization inhibitor or a radical polymerization inhibitor in order to enhance the stability during storage. As the radical polymerization inhibitor or the radical polymerization inhibitor, for example,
p-methoxyphenol, diphenyl-p-benzoquinone, benzoquinone, hydroquinone, pyrogallol, phenothiazine, resorcinol, orthodinitrobenzene, paradinitrobenzene, metadinitrobenzene, phenanthraquinone, N-phenyl-1-naphthylamine, N-phenyl-2- Examples include naphthylamine, cuperon, phenothiazine, 2,5-toluquinone, tannic acid, parabenzylaminophenol, nitrosamines and the like. These are used alone or in combination of two or more.

The amount of the radical polymerization inhibitor or the radical polymerization inhibitor to be used is 0.0 to the amount of the polyimide precursor.
1 to 30% by weight, preferably 0.05 to 10% by weight.
It is more preferable to set the weight%. This usage amount is 0.
If it is less than 01% by weight, stability during storage tends to be poor, and if it exceeds 30% by weight, photosensitivity and mechanical properties of the film tend to be inferior.

Each of the above-mentioned materials is dissolved or dispersed in an organic solvent as necessary to form a photosensitive resin composition. As the organic solvent, a polar solvent that completely dissolves the polyimide precursor is preferable. For example, N-methyl-2-pyrrolidone, N,
N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, tetramethylurea, hexamethylphosphoric triamide, γ-butyrolactone, and the like are preferred. In addition to these polar solvents,
Ketones, esters, lactones, ethers, halogenated hydrocarbons, hydrocarbons and the like can also be used, for example, acetone, diethyl ketone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone,
Methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, diethyl malonate, diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, dichloromethane,
Examples thereof include 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene, o-dichlorobenzene, hexane, heptane, octane, benzene, toluene, and xylene. These organic solvents are used alone or in combination of two or more. The amount used is not particularly limited, but may be 1 to 1% by weight of the polyimide precursor.
It is preferable to use a 0-fold solvent.

The obtained photosensitive resin composition of the present invention is applied onto a base material such as a silicon wafer, a metal substrate, a ceramic substrate or the like by a dipping method, a spray method, a screen printing method, a spin coating method or the like. By heating and drying the portion, a coating film having no tackiness can be obtained. There is no particular limitation on the thickness of this coating film.
The thickness is preferably from 50 to 50 μm, more preferably from 6 to 40 μm, particularly preferably from 10 to 40 μm, and most preferably from 20 to 35 μm. On this coating film, after exposure to a pattern by irradiating actinic rays or actinic rays through a mask on which a desired pattern is drawn, the unexposed portion is developed and dissolved with an appropriate developing solution,
By removing, a desired relief pattern can be obtained.

The photosensitive resin composition of the present invention is designed to be suitable for exposure with an i-line stepper. For example, a contact / proximity exposure machine using an ultra-high pressure mercury lamp, a mirror projection exposure machine, a g-ray stepper, other ultraviolet rays, a visible light source, X
Wires, electron beams and the like can also be used. As the developer, for example, a good solvent (N, N-dimethylformamide,
N, N-dimethylacetamide, N-methyl-2-pyrrolidone, etc.), a mixed solvent of the above good solvent and a poor solvent (lower alcohol, ketone, water, aromatic hydrocarbon, etc.), and a basic solution (tetramethyl hydroxide) Aqueous ammonium solution, aqueous triethanolamine solution).

After the development, if necessary, it is preferable to wash with water or a poor solvent and dry at about 100 ° C. to make the pattern stable. In addition, the relief pattern is heated to close the imide ring by heating to form a patterned highly heat-resistant polyimide film. The heating temperature at this time is preferably from 150 to 500 ° C, more preferably from 200 to 400 ° C. If the heating temperature is lower than 150 ° C., the mechanical and thermal properties of the polyimide film tend to decrease, and if it exceeds 500 ° C., the mechanical and thermal properties of the polyimide film tend to decrease. The heating time at this time is 0.05
It is preferably set to 10 to 10 hours. This heating time
If less than 0.05 hours, the mechanical properties and thermal properties of the polyimide film tend to decrease, and if more than 10 hours,
The mechanical and thermal properties of the polyimide film tend to decrease.

As described above, the photosensitive resin composition of the present invention can be used for a surface protective film of a semiconductor element, an interlayer insulating film of a multilayer wiring board, and the like. In particular, a polyimide pattern is obtained on a base material on which a passivation film is formed by the above method, and the passivation film is etched and processed using the polyimide pattern as a mask. Can be.

Here, the processing of the passivation film usually means that SiO, S
This is a process for opening a conduction portion of a passivation film formed using an inorganic substance such as iN. Note that the polyimide pattern remaining on the passivation film prevents physical influence from the sealing agent and functions as a surface protection film. In addition, the processing of the passivation film is preferably a processing of removing the passivation film on the bonding pad and on the compensation circuit by dry etching or the like, from the viewpoint of improving yield.

[0054]

The present invention will be described below with reference to examples. Examples 1 to 7 and Comparative Examples 1 to 3 In a 100 ml flask equipped with a stirrer and a thermometer, Table 1 was added.
The diamine component and N-methyl-2-pyrrolidone shown in (1) were added, and the mixture was stirred and dissolved at room temperature. The acid component shown in Table 1 was added to this solution, and the mixture was stirred for 30 hours to give a viscous polyimide precursor solution. Obtained. Further, this solution was heated at 70 ° C. for 5 hours, the viscosity was adjusted to 80 poise (solid content: 25% by weight), and the polyimide precursor solution (PI-1 to PI-10)
And In addition, a diamine component, an acid component and N-methyl-
The amounts of 2-pyrrolidone used are shown in Table 1.

The viscosity was measured using an E-type viscometer (Toki Sangyo Co., Ltd.)
, EHD type) at a temperature of 25 ° C and a rotation speed of 2.
It was measured at 5 rpm. The dried polyimide precursor solution (PI-1 to PI-10) was dried with K
By the Br method, an infrared absorption spectrum (manufactured by JEOL Ltd.,
(JIR-100 type) were measured.
The absorption of C = O of the amide group around 00 cm-1 and 3300 cm
The absorption of NH was confirmed near ^-1 .

[0056]

[Table 1]

* Abbreviations ODPA: oxydiphthalic dianhydride, PMDA: pyromellitic dianhydride s-BPDA: biphenyltetracarboxylic dianhydride,
SIDA: bis (3,4-dicarboxyphenyl) dimethylsilane dianhydride SXDA: 1,3-bis (3,4-dicarboxyphenyl) tetramethyldisiloxane dianhydride DFAP: 2,2'-difluoro-4 , 4'-Diaminobiphenyl TFAP: 2,2 ', 5,5'-tetrafluoro-4,
4'-diaminobiphenyl TFDB: 2,2'-bis (trifluoromethyl)-
4,4'-diaminobiphenyl DDE: diaminodiphenyl ether PPD: p-phenylenediamine

With respect to 10 g of the solution of each of the polyimide precursors (PAA-1 to PAA-10) obtained above,
0.027 g of 2,6-bis (4'-azidobenzal) -4-carboxycyclohexanone (CA), 4,4'-
Bis (diethylamino) benzophenone (EAB)
027 g and 1-phenyl-2- (o-ethoxycarbonyl) oxyiminopropan-1-one (PDO).
054 g was added, and further, dimethylaminopropyl methacrylate (MDAP) equivalent to the carboxyl group of the polyimide precursor was added, followed by stirring and mixing to provide a uniform photosensitive resin composition to be used in Examples 1 to 7 and Comparative Examples 1 to 3. A solution was obtained.

[0059]

Embedded image

The obtained photosensitive resin composition solution was filtered through a filter, and each solution was spin-coated on a silicon wafer. Next, the coating was heated at 100 ° C. for 150 seconds using a hot plate to form a coating film of 23 μm, followed by pattern masking and exposure with an i-line stepper at an exposure of 200 mJ / cm ² . This is further heated at 100 ° C. for 60 seconds,
Paddle development was performed using a mixed solution of N-methyl-2-pyrrolidone / water (75/25 (weight ratio)).
00 ° C for 30 minutes, 200 ° C for 30 minutes, 350 ° C for 6 minutes
After heating for 0 minutes, a polyimide relief pattern was obtained. An infrared absorption spectrum of a part of the obtained polyimide relief pattern was measured by the KBr method. As a result, characteristic absorption of the imide was confirmed at around 1780 cm ^-1 .

Each of the obtained polyimide precursors (PAA-1)
To PAA-10), the coefficient of thermal expansion of the polyimide film obtained above, the residual stress on the silicon wafer, the adhesion rate, and the resolution of the relief pattern were evaluated by the following methods. The results are shown in Table 2. The transmittance was measured by spin-coating the obtained resin solution of each polyimide precursor having a photosensitive group and drying at 85 ° C. for 3 minutes and further at 105 ° C. for 3 minutes to obtain a coating film (10 μm).
Was measured with a spectrophotometer. Thermal expansion coefficient is 10μ
m polyimide film at a heating rate of 10 ° C./min.
It was measured by TMA under the condition of 0 g. The residual stress was measured by forming a polyimide film on a 6-inch silicon wafer and using a stress measuring device (type FLX-2320) manufactured by Tencor Corporation. The adhesion rate was determined by forming a polyimide film on a silicon wafer and performing a grid-peeling test using a cellophane tape to evaluate the remaining rate as the adhesion rate. The resolution was evaluated as the minimum size of a developable through hole using a through hole test pattern.

Next, the above Examples 1 to 7 and Comparative Examples 1 to
The relief pattern obtained in 3 at 100 ° C. for 30 minutes,
The polyimide pattern was obtained by heating at 200 ° C. for 30 minutes and under a nitrogen atmosphere at 350 ° C. for 60 minutes. The polyimide patterns obtained from the relief patterns of Examples 1 to 7 had a good trapezoidal pattern shape reflecting that the pattern shape of the relief pattern was rectangular and had good resolution. The polyimide patterns obtained from the relief patterns of Examples 1 to 3 had an undesired inverted trapezoidal pattern shape reflecting that the pattern shape of the relief pattern was inverted trapezoidal and the resolution was poor.

[0063]

[Table 2]

A 10 μm-thick polyimide film prepared using only a resin solution of each polyimide precursor to which a photosensitive group was provided was subjected to a thermal expansion coefficient measurement using TMA at a temperature rising rate of 10 ° C./min and a load of 10 g. As a result of the measurement, the same values as those in Table 2 were obtained.

Example 8 Example 1 except that 2,6-bis (4'-azidobenzal) -4-carboxycyclohexanone was not used.
As a result, the same good results as in Example 1 were obtained.

Example 9 Example 4 except that 2,6-bis (4'-azidobenzal) -4-carboxycyclohexanone was not used.
As a result, the same good results as in Example 4 were obtained.

[0067]

The photosensitive resin composition according to claim 1 has excellent i-line transmittance, adhesiveness to a substrate, and low thermal expansion after imidization. The photosensitive resin composition according to claim 2,
It has excellent i-line transmittance, adhesiveness to a substrate, and low thermal expansion after imidization, and a good pattern can be obtained even at a low exposure dose. The photosensitive resin composition according to the third aspect has the effects of the invention according to the first aspect, and is particularly excellent in adhesiveness to a substrate. The photosensitive resin composition according to the fourth aspect has the effects of the invention according to the first aspect, and is particularly excellent in i-line transmittance. The photosensitive resin composition according to the fifth aspect has the effects of the invention according to the first aspect, and is particularly excellent in low thermal expansion.

According to the method for producing a polyimide pattern of the present invention, a polyimide pattern having high mechanical properties, high heat resistance, low thermal expansion, low thermal stress, and high adhesiveness and dry etching resistance can be obtained. It provides a polyimide pattern with high resolution, dimensional accuracy and pattern shape. According to the method of manufacturing a semiconductor device according to the seventh aspect, a semiconductor device having a polyimide pattern exhibiting the effects of the invention described in the sixth aspect is obtained.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 21/027 H01L 21/312 B 21/312 21/30 502R

Claims (7)

[Claims] 1. A compound of the general formula (I) (Wherein, X represents a tetravalent organic group containing a silicon atom, Y represents a divalent organic group, and R ¹ and R ² represent a photosensitive group). A photosensitive resin composition containing a polyimide precursor having a degree of transparency that does not inhibit the curing reaction by light having a wavelength of 365 nm, and having a coefficient of thermal expansion of 20 ppm / ° C. or less after the polyimide treatment. 2. A compound of the general formula (I) (Wherein, X represents a tetravalent organic group containing a silicon atom, Y represents a divalent organic group, and R ¹ and R ² represent a photosensitive group). Wavelength of the film 36
A photosensitive resin composition comprising a polyimide precursor having a light transmittance of 5% or more per 10 μm of film thickness at 5 nm, and having a coefficient of thermal expansion of 20 ppm / ° C. or less after the polyimide treatment. 3. X in the general formula (I) is the following formula X ¹ : (Wherein, R ³ and R ⁴ each represent a monovalent hydrocarbon group and may be the same or different, and n is 0 or an integer of 1 or more). 3. The photosensitive resin composition according to 2. 4. The photosensitive resin composition according to claim 1, wherein the divalent organic group represented by Y in the general formula (I) contains a fluorine atom. 5. The divalent organic group represented by Y in the general formula (I) is represented by the following formula Y ¹ : The photosensitive resin composition according to claim 1, which is selected from the group consisting of: 6. A photosensitive resin composition according to any one of claims 1 to 5, which is coated on a substrate, dried, exposed in a pattern, and unexposed portions are removed by development to obtain a relief pattern. A method for producing a polyimide pattern, which is followed by heating. 7. A method for manufacturing a semiconductor device, comprising forming a polyimide pattern on a substrate by the method according to claim 6.