JPH01129246A - Photosensitive heat resistant resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin compsn. making treatment at a high temp. after pattern formation unnecessary and having improved resolution, superior heat resistance and high sensitivity by incorporating specified components derived from carboxylic acid and amine into the skeleton of photosensitive polyamide resin. CONSTITUTION:A component derived from dicarboxylic acid and represented by formula I (where Ar is an arom. cyclic group, R* is a photosensitive group and n=1 or 2) and a component derived from diamine and represented by formula II are incorporated into the skeleton of photosensitive polyamide resin. The dicarboxylic acid having the arom. cyclic group Ar in formula I may be isophthalic acid or 3,3'-methylenebisbenzoic acid. The component represented by formula II may be 3,3'-diaminobenzophenone or 4,4'-diaminobenzophenone. By using the polyamide resin, a resin compsn. not requiring baking at a high temp. after pattern formation and having superior heat resistance and high sensitivity is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a photosensitive heat-resistant resin composition containing a photosensitive polyamide resin component which itself has a sensitizing effect.

[Background technology]

Today, photosensitive polyamide resin compositions and photosensitive polyimide resin compositions, which are both photosensitive and have excellent heat resistance, are used as protective films for semiconductors and insulating films between the eyebrows of multilayer circuit boards. Research and development of photosensitive resin precursors and the like is actively progressing, and they are already being used, and the demand for them is increasing.

In general, when photosensitive polymers are used as photosensitive materials such as photoresists for patterning integrated circuits, etc., the main focus is on film strength, including sensitivity, resolution, film-forming ability, and heat resistance. Performance such as (stability) is required. Nowadays, as the pattern size becomes finer due to the higher density of integrated circuits, these requirements are
First of all, it's getting tougher.

However, since such resist performances generally tend to have a contradictory relationship, it is an important issue how to overcome this point. For example, its heat resistance,
Regarding resolution, the photosensitive polyamide/polyimide resins and the like still have contradictory problems as described below.

■ After pattern formation, high-temperature treatment at around 400℃ (high-temperature beta) is required to increase heat resistance, but the film decreases significantly after beta, resulting in blurring.
Resolution deteriorates and it is difficult to obtain a desired pattern.

(2) Even if the above-mentioned high-temperature treatment is not necessary, and therefore resolution may be satisfactory, heat resistance is lacking.

On the other hand, in terms of sensitivity, resist materials with even higher sensitivity are required, but it is not easy to meet this demand. As described above, at this stage, a resist material with a well-balanced performance such as photosensitivity and heat resistance has not yet been developed.

[Purpose of the invention]

In view of the above circumstances, the present invention provides a photosensitive heat-resistant material that does not require high-temperature processing after pattern formation, has good resolution, has excellent heat resistance, and can obtain a highly sensitive pattern. The purpose is to provide a resin composition.

[Disclosure of the invention]

As a result of repeated studies to achieve the above objective, we discovered a new heat-resistant polyamide resin that has a photosensitive group (photosensitive group) in its side chain and has a sensitizing effect on its own, and completed this invention. I ended up letting it happen.

That is, the present invention provides a photosensitive heat-resistant resin composition containing a photosensitive polyamide resin component, in which a carboxylic acid-derived component represented by the following general formula (I) and a general formula (II) are added to the photosensitive polyamide resin skeleton. ) The photosensitive heat-resistant resin composition O is characterized by containing an amine-derived component represented by the following.

The present invention will be explained in detail below.

The above-mentioned polyamide resin skeleton according to the present invention contains at least a dicarboxylic acid having an aromatic cyclic group Ar as shown in the formula (1), that is, a component derived from an aromatic dicarboxylic acid. is necessary. (Here, a dicarboxylic acid is a "compound having two carboxyl groups in one molecule," and the same interpretation applies to the name diamine.) Such dicarboxylic acids include isophthal Examples include, but are not limited to, acids such as 3,3'-methylenebisbenzoic acid. From the viewpoint of reactivity with the amino group described below, the carboxylic acid as a raw material is preferably derivatized into an acyl halide or the like.

The photosensitive group R* bonded to the aromatic ring of the dicarboxylic acid via an amide bond may be any group that is photosensitive, that is, has photoreactivity such as crosslinking or dimerization with light, or polymerization. It is not limited. For example, from vinyl groups, allyl groups, isopropenyl groups, styryl groups, cinnamoyl groups, groups derived from compounds with these olefinic double bonds, and compounds with multi-nitrogen characteristic groups such as azide groups and diazo groups. derived groups, benzalacetophenone, coumarin, pyrone.

Examples include groups derived from photosensitive compounds such as anthracene, benzophenone, benzoin, stilbene, and cyclopropene. This photosensitive group R* represents each dicarboxylic acid 1
It is necessary that one or two fIm be introduced per molecule. If these photosensitive groups R* are of a type that causes photocrosslinking or photopolymerization, photoresists containing them will be used as negative type photoresists that are poorly soluble in exposed areas.

If the above-mentioned photosensitive group R* has been introduced into the aromatic dicarboxylic acid in advance at the monomer stage, the dicarboxylic acid having this photosensitive group R* or its derivative component and the diamine component described below are combined. By polycondensing, a polyamide resin containing the carboxylic acid-derived component of the formula (1) can be reliably obtained. Here, as a method for introducing the photosensitive group R*, for example,
Through a condensation reaction between a carboxylic acid chloride having R* and a dicarboxylic acid having an amino group in its aromatic ring, such as 5-aminoisophthalic acid, the two are easily integrated via an amide bond. An example is shown below.

OOH OOH OOH Next, the diamine-derived component of the formula (■) contained in the polyamide resin has one amino group on each benzene ring of the benzophenone skeleton.
．． Examples include 3'-diaminobenzophenone and 4,4'-diaminobenzophenone, but of the two, the former has the advantage of higher reactivity with acid derivatives such as acid chloride.

The skeleton of the polyamide resin in this invention may be composed only of the acid of formula (1) and the amine-derived component of formula (II) as described above, but it may be copolymerized with other acid components and amine components. May be condensed. In that case, each component of the formulas (I) and (II) is 0% relative to the total amount of acid and amine components constituting the resin skeleton.
．． It is preferable that it accounts for 1 mol% or more.

Other acid components are not particularly limited as long as they can be polycondensed with amines, but from the standpoint of heat resistance, examples include isophthalic acid, terephthalic acid, and derivatives of these acids (acid chlorides, etc.). Preferably, it is an aromatic acid such as Furthermore, it is not limited to carboxylic acids (for example, it may include sulfonic acids and may form a sulfamide bond with the amine.On the other hand, other amine components include , for the same reason, for example, m + or p-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-
Aromatic amines such as diaminodiphenyl ether and 4,4'-diaminodiphenylsulfone are suitable;
It is not limited to these. Incidentally, these other acid and amine components may be used alone or in combination.

The polyamide resin, which is a feature of this invention, is synthesized from the acid component and amine component as described above, and the synthesis (polycondensation) method thereof includes, for example,
Conventional cold solution methods are suitable. That is, first, a diamine component containing a diamine serving as the component of the formula (■) is mixed with a polar solvent such as dimethylformamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone (NMP), or dimethylacetamide (hereinafter referred to as "polar solvent A"). ). To this, an acid component containing a dicarboxylic acid or an easily reactive derivative component thereof such as an acid chloride, which is a component of formula (1), was added and mixed while maintaining a low temperature state of about -20 to 5°C, and the mixture was mixed for 30 minutes. The polycondensation reaction proceeds by continuing stirring for ~ several hours.

The obtained polyamide resin solution is poured into a poor solvent such as alcohol or water (hereinafter referred to as "poor solvent B") to cause precipitation, and the deposited precipitate is filtered.

By drying, a polyamide resin having the components of formulas (1) and (If) in its skeleton can be obtained. Note that the method for polycondensing the acid component and the amine component is not limited to this, and it goes without saying that interfacial polycondensation or the like may be used for synthesis.

The molecular weight of the polyamide resin synthesized in this way is not particularly limited, but from the viewpoint of film-forming ability and strength, the logarithmic viscosity of this resin in a 0.5% by weight NMP solution at 30°C is 0.5%. It is preferable that it is 1 or more.

Up to now, the photosensitive polyamide resin synthesized by polymerizing a monomer having a photosensitive group R* in its molecular structure has been exemplified, but in this invention, the process for forming this resin is as follows. It is not limited to this. That is, the photosensitive group R* may be formed by pendant to the existing polyamide resin by a polymer reaction, and the photosensitive group R* may be formed by a polymer reaction or a polymerization reaction.
It may be of a type in which the structure appears for the first time. In short, it is sufficient to obtain a photosensitive polyamide resin containing in its skeleton the component of formula (1) and the component (II) having the photosensitive group R*.

The photosensitive heat-resistant resin composition according to the present invention containing the photosensitive polyamide resin as described above contains a benzophenone skeleton, which is effective as a sensitizer, in the resin skeleton, so it is particularly difficult to add a sensitizer. However, if necessary, at least one of a sensitizer, a photopolymerization initiator, a photopolymerizable additive, etc. may be added. You can leave it there. Furthermore, thermal polymerization inhibitors, colorants such as various dyes and pigments, plasticizers, solvents, and the like may be included.

The sensitizer and polymerization initiator used are not particularly limited, and include, for example, benzoin methyl ether, benzoin ethyl ether, benzoin dimethyl ether,
Benzoins such as benzoin diethyl ether and benzoin isopropyl ether, thioxanthone such as thioxanthone, chlorothioxanthone, and alkylthioxanthone, xanthone, benzophenone, benzophenone such as 4,4'-bisdimethylaminobenzophenone, acetophenone, oxime, anthraquinone Common quinones such as polynuclear quinones can be used.

Photopolymerizable materials include mono (meth)acrylates such as methyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and ethylene glycol. Di(meth)acrylate, diethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, etc.
meth)acrylates, trimethylolpropane tri
(meth)acrylate, tetramethylolmethanetri
Examples include trifunctional or higher functional (meth)acrylates such as (meth)acrylate and tetramethylolmethanetetra(meth)acrylate, but the present invention is not limited thereto. That is, the photopolymerizable group may be an acrylamide group, an allyl group, a vinyl ether group, a vinylamino group, a glycidyl group, an acetylenically unsaturated group, etc. other than the above-mentioned (meth)acryloyl group.

The above sensitizer, photopolymerization initiator and photopolymerizable polymer are:
They may be used alone or in combination. The amount of the sensitizer and photopolymerization initiator added to the polyamide resin is preferably 0.01 to 20% by weight, more preferably 0.1 to 10% by weight. If the blending amount exceeds 20% by weight, the physical properties of the cured resin tend to deteriorate significantly.
If the amount is less than 0.01% by weight, the purpose of adding them, that is, improving photoreactivity, may not be fully achieved.

Regarding the photopolymerizable additive, it is 0.01 to 200% by weight, more preferably 0.1 to 50% by weight based on the polyamide resin.
It is appropriate that the amount is blended within a range of % by weight. If the amount is less than 0.01% by weight, the purpose of adding it, that is, improvement in sensitivity, will not be achieved sufficiently, and 200% by weight.
If it exceeds % by weight, the heat resistance of the cured product may deteriorate significantly.

The photosensitive heat-resistant resin composition of the present invention as described above is used as a pattern forming material for integrated circuits in the same way as conventional photoresists. It is good to use it in a state. The solution concentration is preferably 1 to 40% by weight, but is not limited thereto. However, if the concentration of the solution is less than 1% by weight, the concentration may be too low and a sufficient film thickness, that is, a coating film with sufficient film function, may not be obtained.On the other hand, if it exceeds 40% by weight, , the solubility in solvents tends to be poor.

As a patterning method, first, the above solution is applied onto a substrate using a spinner, roll coater, spray, or the like. At this time, it is recommended that the coating be applied uniformly to avoid pinholes, striations (striped patterns due to variations in film thickness), etc., and to form a highly accurate coating film.

Next, the substrate is heated and dried to remove the solvent from the applied solution, and then a photomask with a predetermined pattern drawn thereon is closely attached and exposed to electromagnetic waves such as ultraviolet rays. A relief pattern can then be obtained by performing development with a solvent or the like using a conventional method and dissolving and removing the unexposed portions. Note that if the heating temperature for removing the solvent at this time exceeds 100° C., there is a risk that the polyamide resin will gel, so it is preferable to perform the heating at a temperature lower than that. In addition, good results can be obtained when a mixed solution of the polar solvent A and poor solvent B is used as the developer during development.

The obtained relief pattern already has sufficient heat resistance as it is, but in order to further improve it, it can be heat-treated at about 100 to 300° C. after development. Here, it goes without saying that film thinning and the like do not become a problem at this temperature.

In the photosensitive heat-resistant resin composition according to the present invention, which has been explained above, the following three points can be listed as its characteristics. Namely; First, since it contains polyamide (aramid) containing an aromatic ring in the main chain as a constituent component, it has excellent heat resistance. This aramid has a flat, highly symmetrical aromatic ring in its main chain, which reduces the degree of freedom of the polymer chain and makes it a rigid molecule, improving heat resistance. Because of the hydrogen bonds that originate from it, it becomes stronger.

Second, since the photosensitive group R* is directly bonded to the heat-resistant polyamide resin skeleton via an amide bond, it is more thermally stable than conventional photosensitive groups. Therefore, a relief pattern with high heat resistance can be formed even though it is not necessary to remove it by baking after development. In other words, a pattern can be obtained that satisfies both resolution and heat resistance, which have been problems in the past. Incidentally, since the conventional photosensitive group was bonded to the resin skeleton mainly through a thermally unstable ester bond, it was necessary to decompose this ester moiety by heating.

Thirdly, since it contains a composition with a sensitizing effect, that is, a benzophenone skeleton, it also has the advantage of high sensitivity.

Note that the application of the photosensitive heat-resistant resin composition according to the present invention is not limited to the photoresist for buttering as described above, but also for other applications in the electronics industry, such as It can be widely used as photoresists and dry films for processing precision parts such as printed wiring boards, as various plate-making materials in the printing industry, and as photosensitive materials or copying materials in other industrial fields.

Next, examples and comparative examples of the present invention will be described.

(Example 1) ■ 10 g of 5-aminoisophthalic acid for boamide
11.5 g of methacrylic chloride while stirring while keeping the temperature at °C.
was added dropwise over 20 minutes.

Thereafter, the mixture was stirred at 5 to 10° C. for 2 hours, and the resulting reaction solution was poured into a 5% aqueous hydrochloric acid solution to obtain a precipitate.

This was collected by filtration and recrystallized from a water/ethanol mixed solution to obtain 7.5 g of 5-methacrylamidoisophthalic acid.

Add 30 d of thionyl chloride to 7.0 g of the obtained product,
The mixture was refluxed for about 1 hour to carry out a chlorination reaction of the dicarboxylic acid portion of the product. After the reaction was completed, unreacted thionyl chloride was removed using an evaporator, and the remaining solid was recrystallized from n-hebutane to obtain 7.0 g of 5-methacrylamidoisophthalic acid chloride.

Next, 2.12 g of 3.3'-diaminobenzophenone
was dissolved in 14.6 g of NMP and cooled to -5°C. While maintaining the temperature, 2.86 g of the above 5-methacrylamidoisophthalic acid chloride was added while stirring, and stirring was continued for 15 minutes. Furthermore, the reaction was completed by stirring at room temperature for 3 hours, and 30 g of NMP was added thereto to obtain a reaction solution.

This reaction solution was dropped into a water/methanol (1/1) mixed solution 11 with vigorous stirring to precipitate the synthesized polyamide. The precipitate was collected by filtration, washed several times with water, and then vacuum dried at 50°C.
was obtained (yield: 4.0 g).

■ Polyamide (X) (U of A composition was prepared.

(Examples 2 to 7) In the same manner as in Example 1, a polyamide was synthesized by reacting the dicarboxylic acid component and the diamine component shown in Table 1,
Polyamide resin compositions were prepared in the same manner. In Examples 2.5 and 7, 4.4' was used as the sensitizer.
-0.04 g of diethylaminobenzophenone was also used.

(Comparative Example 1.2) Using only p-methylene dianiline as the diamine component, polyamide was synthesized in the same manner as in Example 1 above, and each component shown in Table 1 was blended to form a resin composition. I prepared something.

■ N-heat dyeing The solutions of the resin compositions obtained in the above Examples and Comparative Examples were applied onto a silicon wafer using a spinner.
Drying was carried out at 0°C for 3 hours to obtain a coating film with a thickness of about 20p.

A 500 W ultra-high pressure mercury lamp (light intensity at the irradiation part: 5 m W /
cJ) was irradiated with ultraviolet light for 6 minutes.

The resin film after irradiation with light was subjected to thermogravimetric analysis and glass transition point (Tg) measurement using a viscoelastic method to examine heat resistance.

The results are shown in Table 1.

■ A gray scale with stepwise differences in the amount of transmitted light as a photomask on a silicon wafer substrate on which a coating film was formed in the same manner as above (Kodak Photographic Step Tablet Floor 2) were placed in close contact with each other, and UV rays were irradiated in the same manner. After that, this substrate was subjected to NMP/
Developing was performed for 2 minutes using an isopropyl alcohol (5/2 parts by weight) mixed solution, and the maximum number of gray scale steps (plate number) at which a residual film was obtained was determined. In other words, the minimum amount of light that leaves the film on the substrate due to exposure is determined, and as the number of stages increases, the amount of transmitted light in the gray scale decreases, and therefore, the sensitivity is evaluated as high.

The results are also shown in Table 1.

As shown in Table 1, the examples using the photosensitive heat-resistant resin composition of the present invention have excellent heat resistance and good sensitivity despite not undergoing beta testing at high temperatures. found.

〔Effect of the invention〕

The photosensitive heat-resistant resin composition according to the present invention is as described above, and has a photosensitive group in the side chain as seen in the skeleton components represented by formulas (I) and (II), and
It is characterized by containing a novel aromatic polyamide resin that itself has a sensitizing effect. So, for example,
By applying this composition to pattern formation as a photoresist, it is possible to obtain a pattern that has excellent heat resistance and good sensitivity without requiring high-temperature beta after pattern formation.

Agent: Patent Attorney Takehiko Matsumoto

Claims (1)

[Claims] (1) In a photosensitive heat-resistant resin composition containing a photosensitive polyamide resin component, the photosensitive polyamide resin skeleton has a carboxylic acid-derived component represented by the following general formula (I) and a component represented by the general formula (II). A photosensitive heat-resistant resin composition characterized by containing an amine-derived component. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) However, in the formula, Ar represents an aromatic cyclic group, R* represents a photosensitive group, and n represents an integer of 1 or 2.