JP3163748B2 - Actinic radiation sensitive polymer composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actinic radiation-sensitive polymer composition, and more particularly to an improvement in a photosensitive polyimide composition having excellent sensitivity.

[0002]

2. Description of the Related Art As a photosensitive polyimide composition, a polyamic acid which can be dimerized or polymerized by actinic radiation is used.
A composition to which a compound containing a carbon double bond and an amino group or a quaternary salt thereof is added (for example, JP-B-59-5282).
No. 2) or a polyimide precursor composition in which photosensitivity is introduced into a polyamic acid by an ester group (for example, US Pat.
No. 12, US Pat. No. 4,408,831) are known.

However, the sensitivity of such a conventional composition is not always sufficiently high, and the exposure time becomes long when performing exposure by a step-and-repeat method (stepper) which is currently mainstream. However, it has been pointed out that there is a problem in further improving productivity.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to overcome the disadvantages of the prior art and to provide a high-sensitivity actinic radiation-sensitive polymer composition.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
This is achieved by the following configuration.

(1) a polymer having a structural unit represented by the following general formula [1]:

Embedded image (R ₁ is a trivalent or tetravalent organic group having at least 2 or more carbon atoms, R ₂ is a divalent organic group having at least 2 or more carbon atoms, R ₃ is hydrogen, an alkali metal ion or ammonium And n represents 1 or 2.) (2) a compound [2] containing an unsaturated bond and an amino group or a quaternary salt thereof, and (3) 1 to 10% by weight of light based on the polymer. An actinic radiation-sensitive polymer composition comprising the charge transfer compound [3].

The polymer having the structural unit [1] in the present invention is represented by the following general formula:

Embedded image (R ₁ is a trivalent or tetravalent organic group having at least 2 or more carbon atoms, R ₂ is a divalent organic group having at least 2 or more carbon atoms, R ₃ is hydrogen, an alkali metal ion or ammonium Represents an ion, and n is 1 or 2.), and can be a polymer having an imide ring or other cyclic structure (hereinafter simply referred to as a polyimide-based polymer) by heating or an appropriate catalyst. Is preferred.

In the above structural unit [1], R ₁ is a trivalent or tetravalent organic group having at least two or more carbon atoms. From the viewpoint of the heat resistance of the polyimide-based polymer, R ₁ preferably has a structure in which the bond to the carbonyl group of the polymer main chain is made directly from the aromatic heterocycle. Therefore, R
_{As 1} , a trivalent or tetravalent group containing an aromatic ring or an aromatic heterocyclic ring and having 6 to 30 carbon atoms is preferable.

Preferred specific examples of R ₁ include a pyromellitic acid residue, a 3,3 ', 4,4'-benzophenonetetracarboxylic acid residue, and a 3,3', 4,4'-biphenyltetracarboxylic acid residue. Acid residue, 3,3 ′, 4,4′-diphenylethertetracarboxylic acid residue, 3,3 ′, 4,4
And '-diphenylsulfonetetracarboxylic acid residue.

[0010] R ₁ may be used alone or may be a copolymer.

R ₂ is preferably a divalent group containing an aromatic ring or an aromatic heterocyclic ring and having 6 to 30 carbon atoms.

Preferable specific examples of R ₂ include 4,
4'-diaminodiphenylether residue, 4,4'-diaminodiphenylsulfide residue, 4,4'-diaminodiphenylmethane residue, 4,4'-diaminodiphenylsulfone residue, paraphenylenediamine residue, meta Examples thereof include a phenylenediamine residue, a benzidine residue, and a bisaminophenoxypropane residue. Of course, many others can be used.

In the polymer having the structural unit [1], R ₂ may be composed of only one of these,
Copolymers composed of more than one kind may be used. Furthermore, in order to improve the adhesiveness of the polyimide polymer,
It is also possible to copolymerize an aliphatic group having a siloxane bond as R ₂ as long as the heat resistance is not reduced. Preferred specific examples include bis (3-aminopropyl) tetramethyldisiloxane.

Specific examples of the polymer having the structural unit [1] as a main component include pyromellitic dianhydride and 4,4 ′
-Diaminodiphenyl ether, 3,3 ', 4,4'-
Benzophenonetetracarboxylic dianhydride and 4,4'-
Diaminodiphenyl ether, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and 4,4'-diaminodiphenyl ether, pyromellitic dianhydride and 3,3
3 '-(or 4,4') diaminodiphenyl sulfone, pyromellitic dianhydride and 3,3 ', 4,4'
-Benzophenonetetracarboxylic dianhydride and 3,3 '
-(Or 4,4 ') diaminodiphenyl sulfone,
3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride and 3,3'-(or 4,4 ') diaminodiphenylsulfone, 3,3', 4,4'-biphenyltetracarboxylic dianhydride Object and 3,3'- (or 4,4 ')
Diaminodiphenyl sulfone, pyromellitic dianhydride and 4,4'-diaminodiphenyl sulfide, 3,3
', 4,4'-benzophenonetetracarboxylic dianhydride and 4,4'-diaminodiphenyl sulfide, 3,3
', 4,4'-biphenyltetracarboxylic dianhydride and 4,4'-diaminodiphenyl sulfide, 3,3',
4,4'-benzophenonetetracarboxylic dianhydride and paraphenylenediamine, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and paraphenylenediamine, pyromellitic dianhydride and 3,3' , 4,4 '
-Benzophenonetetracarboxylic dianhydride and paraphenylenediamine, pyromellitic dianhydride and 3,3
', 4,4'-biphenyltetracarboxylic dianhydride and paraphenylenediamine, 3,3', 4,4'-diphenylethertetracarboxylic dianhydride and 4,4'-diaminodiphenylether , 3,3 ', 4,4'-diphenylethertetracarboxylic dianhydride and paraphenylenediamine, pyromellitic dianhydride and 4,4'-diaminodiphenylether and bis (3-aminopropyl A) Polyamic acid synthesized from, for example, tetramethyldisiloxane.

The polymer having the structural unit [1] may be composed of only the structural unit [1], or may be a copolymer or a blend with another structural unit. It is desirable that the type and amount of the structural unit used for copolymerization be selected within a range that does not significantly impair the heat resistance of the polyimide polymer obtained by the final heat treatment.

The compound [2] containing an unsaturated bond and an amino group or a quaternized salt thereof includes a compound containing a carbon-carbon double bond and an amino group or a quaternized amino group in one molecule. .

Preferred specific examples include dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, diethylaminoethyl methacrylate, diethylaminoethyl acrylate, dimethylaminopropyl methacrylamide, vinylpyridine and the like. But
It is not limited to these.

From the standpoint of actinic radiation sensitivity, an amino compound having an acryl group or a methacryl group as an unsaturated group is particularly desirable.

In the case of a compound in which the amino group is not quaternized, it is desirable to combine with a compound in which R ₃ of the structural unit [1] is hydrogen. In the case of a compound in which the amino group is quaternized, it is desirable that R ₃ of the structural unit [1] be combined with an alkali metal ion or an ammonium ion.

The compound [2] contains 0.1% of all carboxyl groups (or salts thereof) of the polymer having the structural unit [1] as a main component.
It is desirable that the polymer is mixed with the polymer in an amount of at least 05 equivalent, preferably at least 0.3 equivalent, and not more than twice equivalent. If the ratio is out of this range, the photosensitivity may be deteriorated, or the allowable range of the developing conditions such as the developing time and the temperature may be narrowed.

As the photocharge transfer compound [3], if it is a compound usually used as a positive charge transfer agent for electrophotography,
Any one can be preferably used. Examples of such are bis (diethylaminophenyl) -1,3,4-oxadiazol, diphenylbenzidine, 2,3-bis (dimethylaminophenyl)-
4- (2-chlorophenyl) oxazole, N, N, N
Many are known, such as', N'-tetrakis (3-methylphenyl) -metaphenylenediamine, α-phenyl-4-N, N'-diphenylaminostilbene, paradiethylaminophenyl-diphenylhydrozide (for example, , Electrochemistry 60, No. 4, 273 (1992)),
Any material that stably holds a positive charge can be used effectively.

In the present invention, the photocharge transfer compound [3]
Causes a charge transfer reaction between the polymer and the polymer main chain, thereby generating an anion radical in the polymer main chain. The anion radical chemically reacts with the compound [2] to form an image. You. For this reason, it is preferable to efficiently generate anion radicals in the main chain in order to improve sensitivity.

The light charge transfer compound is preferably in the al,
It is added in an amount of 1 to 10% by weight based on the polymer. If the amount is out of this range, no effective sensitivity will be exhibited if the amount is too small, and if the amount is too large, it will remain after the polyimide is formed by applying heat to the polymer, adversely affecting the electrical properties, mechanical properties, adhesiveness and the like.

In order to further improve the sensitivity, a sensitizer such as Michler's ketone can be added.

Such a sensitizer is added to the polymer in an amount of 0.1%.
It is preferable to add in the range of -5% by weight. If the ratio is outside this range, the photosensitivity is reduced and the mechanical properties of the polymer are reduced.

An example of the method for producing the composition of the present invention will be described. First, a diamine compound and an acid dianhydride are reacted in a solvent to obtain a polymer mainly containing the structural unit [1]. Next, compounds [2] and [3] and, if necessary, other additives can be dissolved in this solution to prepare a solution. As the above-mentioned polymer, a solid polyamic acid polymer or a polymer separated and purified from a solution after the reaction may be used after being dissolved again.

As the solvent used in the above production method, a polar solvent is preferably used from the viewpoint of solubility of the polymer, and an aprotic polar solvent is particularly preferable. Examples of the aprotic polar solvent include N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide,
Dimethyl sulfoxide, hexamethyl phosphorotriamide, γ-butyrolactone, dimethylaminoacrylamide and the like are preferably used. As other additives, a copolymer monomer or a material having good adhesion to a substrate may be contained as long as the sensitivity and heat resistance are not significantly reduced.

Next, the method of using the composition of the present invention will be described. The composition of the present invention can be patterned by a well-known fine processing technique using actinic radiation.

First, the composition of the present invention is coated on a suitable support. Examples of the coating method include spin coating using a spinner, spray coating using a spray coater, immersion, printing, roll coating, and the like. The coating thickness can be adjusted by the coating means, the solid content concentration of the composition, and the viscosity.

Examples of the material of the support on which the composition of the present invention is applied include metals, glass, semiconductors, metal oxide insulators, and silicon nitride.

In order to improve the adhesion between the coating film of the composition of the present invention or the polyimide film after the heat treatment and the support, an adhesion aid may be appropriately used.

As an adhesion aid, an organosilicon compound such as oxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, or aluminum monoethyl Aluminum chelate compounds such as acetoacetate diisopropylate and aluminum tris (acetylacetonate) or titanium bis (acetylacetonate)
Titanium chelate compounds and the like are preferably used.

Next, the composition of the present invention, which has been formed into a coating film on the support, is irradiated with actinic radiation in a desired pattern. Examples of the actinic ray include X-rays, electron beams, ultraviolet rays, and visible rays, but ultraviolet rays and short-wavelength visible rays, that is, 200 to 500 nm in a wavelength range are preferable.

Then, the non-irradiated portion is dissolved and removed with a developing solution to obtain a relief pattern. An appropriate developer is selected according to the structure of the polymer.

As a developer, N- solvent which is a solvent of the present composition is used.
Methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide, hexamethylphosphortriamide, etc., alone or in methanol, ethanol, isopropyl alcohol , Water, methyl carbitol, ethyl carbitol, toluene, xylene, and the like as a mixture with a non-solvent.
In many cases, aqueous ammonia or other alkaline aqueous solutions can be used.

The development can be carried out by spraying the above-mentioned developing solution on the coating film surface, dipping in the developing solution, or applying ultrasonic waves while dipping. The relief pattern formed by development is desirably washed with a rinse solution. As the rinsing liquid, methanol, ethanol, isopropyl alcohol, butyl acetate, and the like having good miscibility with the developing solution are preferably used.

The relief pattern polymer obtained by the above treatment is a precursor of a polyimide polymer having heat resistance, and becomes a heat resistant polymer having an imide ring or other cyclic structure by heat treatment. The heat treatment temperature is 135-
Performed at 400 ° C. The heat treatment is usually performed stepwise or continuously while increasing the temperature.

The actinic radiation-sensitive polymer composition of the present invention can be used as a passivation film of a semiconductor, a buffer coat film of a passivation film, an interlayer insulating film of a multilayer integrated circuit, or an interlayer insulating film of a hybrid integrated circuit. And surface protective films, soldering protective films for printed circuits, liquid crystal alignment films, interlayer insulating films for mounting boards, and the like. Further, it is also possible to apply a metal as a highly heat-resistant photoresist or a dry etching process. It can be applied to other known uses of polyimide.

[0039]

According to the present invention, as described above, the structural unit [1]
Actinic radiation comprising: a polymer mainly composed of: a compound [2] containing an unsaturated bond capable of being dimerized or polymerized by actinic radiation and an amino group or a quaternized salt thereof; and a photocharge transfer material [3] By forming a composition having a high sensitivity, an actinic ray-sensitive polymer composition having a high sensitivity, which has not been seen in the past, can be obtained.

[0040]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.

[Synthesis of Polyimide Stock Solution] 100.1 g of 4,4′-diaminodiphenyl ether was added to N-methyl-2.
-Dissolved in 670 g of pyrrolidone at room temperature, 3,3 ',
4,4'-benzophenonetetracarboxylic acid 157.5
g was added together with 103 g of N-methyl-2-pyrrolidone, followed by vigorous stirring. At this time, the liquid temperature rises rapidly and reaches 50 ° C., after which it enters a steady state. The reaction was continued at 30 ° C. for 1 hour, and the reaction temperature was further raised to 60 ° C. for 4 hours.

[Synthesis of Photosensitive Polyimide Stock Solution] When the temperature of the polyimide stock solution returned to room temperature, 157 g of dimethylaminoethyl methacrylate was added together with 70 g of N-methyl-2-pyrrolidone, and the mixture was stirred at room temperature for 2 hours.

Example 1 A photosensitive polyimide prepared by adding 1.0 g of bis (diethylaminophenyl) -1,3,4-oxadiazol (4.9% by weight to the polymer) to 100 g of the above photosensitive polyimide stock solution. A solution was made.

This solution was applied on a silicon wafer by spin coating. The coating thickness was 10 μm after baking at 80 ° C. for 1 hour. After the wafer was baked at 80 degrees for 1 hour, the wafer was baked using a Nikon step-and-repeat type exposure apparatus NSR-1505G6E.
Exposure processing was performed in an exposure range of 50 to 1000 milliseconds, and development was performed using a developer consisting of 60 parts by weight of N-methyl-2-pyrrolidone and 40 parts by weight of methanol.

As a result, a pattern could be obtained when the exposure time was 100 milliseconds (exposure energy: 50 mJ / cm ² (436 nm)), and it was found that the sensitivity was extremely high.

Example 2 0.6 g of N, N, N was added to 100 g of the photosensitive polyimide stock solution.
A photosensitive polyimide solution to which ', N'-tetrakis (3-methylphenyl) -metaphenylenediamine (2.9% by weight based on the polymer) was added was prepared.

This solution was applied on a silicon wafer by spin coating. The coating thickness was 10 μm after baking at 80 ° C. for 1 hour. After the wafer was baked at 80 degrees for 1 hour, the wafer was baked using a Nikon step-and-repeat type exposure apparatus NSR-1505G6E.
Exposure processing was performed in an exposure range of 50 to 1000 milliseconds, and development was performed with a developer consisting of 60 parts by weight of N-methyl-2-pyrrolidone and 40 parts by weight of xylene.

As a result, a pattern could be obtained when the exposure time was 150 milliseconds (exposure energy -75 mJ / cm ² (436 nm)), and it was found that the sensitivity was extremely high.

Example 3 A photosensitive polyimide solution obtained by adding 0.6 g of α-phenyl-4-N, N′-diphenylaminostilbene (2.9% by weight to the polymer) to 100 g of the photosensitive polyimide stock solution. Created.

This solution was applied on a silicon wafer by a spin coating method. The coating thickness was 10 μm after baking at 80 ° C. for 1 hour. After the wafer was baked at 80 degrees for 1 hour, the wafer was baked using a Nikon step-and-repeat type exposure apparatus NSR-1505G6E.
Exposure processing was performed in an exposure range of 50 to 1000 milliseconds, and development was performed using a developer consisting of 60 parts by weight of N-methyl-2-pyrrolidone and 40 parts by weight of methanol.

As a result, a pattern was obtained at an exposure time of 200 milliseconds (exposure energy: 100 mJ / cm ² (436 nm)) or more, and it was found that the sensitivity was very high.

Example 4 A photosensitive polyimide solution was prepared by adding 0.6 g of para-diethylaminophenyl-diphenylhydrazide (2.9% by weight to the polymer) to 100 g of the photosensitive polyimide stock solution.

This solution was applied on a silicon wafer by a spin coating method. The coating thickness was 10 μm after baking at 80 ° C. for 1 hour. After the wafer was baked at 80 degrees for 1 hour, the wafer was baked using a Nikon step-and-repeat type exposure apparatus NSR-1505G6E.
Exposure processing was performed in an exposure range of 50 to 1000 milliseconds, and development was performed using a developer consisting of 60 parts by weight of N-methyl-2-pyrrolidone and 40 parts by weight of methanol.

As a result, a pattern was obtained at an exposure time of 200 milliseconds (exposure energy: 100 mJ / cm ² (436 nm)) or more, and it was found that the sensitivity was very high.

Comparative Example 1 A photosensitive polyimide solution was prepared by adding 1.0 g of "IRGACURE" 907 (a photopolymerization initiator manufactured by Ciba-Geigy Corporation) (4.9% by weight to the polymer) to 100 g of the photosensitive polyimide stock solution. did. This solution was applied on a silicon wafer by a spin coat method. The coating thickness was 10 μm after baking at 80 ° C. for 1 hour. This wafer is placed at 80 degrees for 1
After performing the time baking process, the exposure process is performed in the exposure range of 50 to 1000 milliseconds using a Nikon step and repeat type exposure apparatus NSR-1505G6E to obtain N-methyl-2- 60 parts by weight of pyrrolidone,
When development was carried out with a developing solution comprising 40 parts by weight of methanol, all the regions were dissolved.

As a result, it was found that this sensitizer had no practical sensitivity to g-line.

Comparative Example 2 A polyimide solution was prepared by adding 1.5 g of bis (diethylaminophenyl) -1,3,4-oxadiazol (6.0% by weight to the polymer) to 100 g of a stock solution of polyimide.

This solution was applied on a silicon wafer by spin coating. The coating thickness was 10 μm after baking at 80 ° C. for 1 hour. After the wafer was baked at 80 degrees for 1 hour, the wafer was baked using a Nikon step-and-repeat type exposure apparatus NSR-1505G6E.
Exposure was performed in an exposure range of 50 to 1000 milliseconds, and development was performed with a developer consisting of 60 parts by weight of N-methyl-2-pyrrolidone and 40 parts by weight of methanol. did.

As described above, it can be seen that the photosensitivity is reduced when the compound [2] is not present.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-160140 (JP, A) JP-A-3-37652 (JP, A) JP-A-56-62247 (JP, A) JP-A-1- 210944 (JP, A) JP-A-2-90166 (JP, A) JP-A-3-87743 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03F 7/038 G03F 7 / 027 G03F 7/028 H01L 21/027 H01L 21/312

Claims (2)

(57) [Claims] 1. A polymer having a structural unit represented by the following general formula [1]: (R ₁ is a trivalent or tetravalent organic group having at least 2 or more carbon atoms, R ₂ is a divalent organic group having at least 2 or more carbon atoms, R ₃ is hydrogen, an alkali metal ion or ammonium And n represents 1 or 2.) (2) a compound [2] containing an unsaturated bond and an amino group or a quaternary salt thereof, and (3) 1 to 10% by weight of light based on the polymer. An actinic radiation-sensitive polymer composition comprising the charge transfer compound [3]. 2. Bis (diethylaminophenyl) -1,
3,4-oxadiazole, diphenylbenzidine,
2,3-bis (dimethylaminophenyl) -4- (2-
Chlorophenyl) oxazole, N, N, N ', N'-
Tetrakis (3-methylphenyl) -metaphenylene
Amine, α-phenyl-4-N, N′-diphenylamido
Nostilbene, para-diethylaminophenyl-diphenyl
At least one photocharge transfer selected from ruhydrozide
2. The actinic radiation according to claim 1, comprising a compound.
A responsive polymer composition.