JP2001081138A - Acid sensitive resin, resin composition for active energy ray comprising the acid sensitive resin and method for forming pattern using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an acid sensitive vinyl resin useful as a material for high performance photoresists of a chemical amplification type by bringing a monomer to contain a hydroxybicycloalkanesulfonate residue having acid propagating function for generating acids by the action of the acid in its side chain. SOLUTION: A monomer is brought to contain a 2-hydroxybicycloalkane-1- sulfonate residue having an acid propagating function to generate acids by the action of the acid and expressed by formula I (R1 and R2 are each H or methyl; m+n is 2 and m is 1 or 2) in its side chain. The objective acid sensitive resin is obtained by radically (co)polymerizing the acid propagating monomer expressed by formula II (R3 is nothing or a divalent residue; R4 is H or methyl), (e.g. a monomer expressed by formula III or the like). This resin composition sensitive to active energy rays is obtained by adding an acid generating agent for generating a strong acid by active energy rays and further an acid propagating agent for generating new acids by the action of the acid to the aforesaid resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acid-sensitive resin, a resin composition for active energy rays comprising the acid-sensitive resin, and a pattern forming method using the same. More specifically, the present invention relates to the generation of an acid by the action of an acid. -Sensitive resin obtained by bonding a molecular group (hereinafter, referred to as an acid-proliferating group) and a process for producing the same, and an activity comprising a substance that generates an acid by the action of an actinic ray (hereinafter, referred to as an acid generator) The present invention relates to an energy ray resin composition and a pattern forming method using the same.

[0002]

2. Description of the Related Art A resin or its composition which is sensitive to active energy rays such as light, infrared rays, electron beams or X-rays can be used as a pattern forming material, or a monomer or prepolymer caused by irradiation with light or electron beams. It has been put to practical use in various fields, such as using curing for surface coating treatment.
Among the actinic rays, light is most widely used, and hereinafter, the actinic rays will be specified and described as light. However, the acid-sensitive resin of the present invention or the active-energy ray resin composition comprising the acid-sensitive resin is described below. Is not limited to light.

The photosensitive speed, photosensitive wavelength range, and resolution of these resins or their compositions are various. Appropriate properties are selected according to the purpose, and a suitable photosensitive resin or composition is selected. It is. However, each had the following essential problems. Large-scale and high-resolution photosensitive materials have been used in a wide range of photosensitive resins mainly composed of high-molecular materials (edited by Ao Yamaoka and Mototaro Nagamatsu, "Photopolymer Technology", Nikkan) Kogyo Shimbun (1988)). The polymer-based photosensitive material has not only excellent resolution but also many advantages such that a wide range of photosensitive wavelength can be set by selecting a photoreaction, and it can be manufactured at relatively low cost. On the other hand, it is desired to shorten the time required to form an image or a pattern while maintaining excellent resolution, and to improve productivity. For this purpose, development of a photosensitive material having high sensitivity is desired.

Until now, various attempts have been made to improve the photosensitive speed of a photosensitive resin material. The most widely developed object is a photopolymerization system that uses a radical species generated by the action of light as an initiator to polymerize many vinyl monomers in a chain. In addition, a cationic polymerization system that generates an acid by the action of light and uses the acid as a catalyst is also actively developed. In cationic polymerization,
Unlike radical polymerization, there is no effect of terminating the reaction by oxygen, so high sensitivity is expected.However, due to moisture in the air and network structure formation, the photosensitivity is actually lower than that of radical polymerization. It is.

On the other hand, in a polymer photosensitive material incorporating an acid-catalyzed reaction utilizing an acid generated by light as a catalyst, a heat treatment is performed after the acid is generated by light, and the polymer substance itself or a high-molecular-weight material is heated. A chemical change of a low-molecular substance dissolved and dispersed in a molecule is induced, and the resulting change in solubility is used for image formation. Because a variety of acid-catalyzed reactions are available,
This type of photosensitive resin composition called a chemically amplified photoresist is widely used. Furthermore, since the reaction involves an acid-catalyzed reaction, it is possible in principle to increase the sensitivity. However, in practice, no remarkable increase in sensitivity has been achieved due to restrictions due to diffusion in a solid.

[0006] Despite the use of an acid-catalyzed reaction, the photosensitivity of a chemically amplified photoresist not only does not become so high, but also the acid generated by light irradiation contains a trace amount of a basic substance present in the environment. It has been pointed out that since the neutralization is carried out, the shape of the formed relief pattern is impaired, and the resolution is substantially reduced. As a method for solving such a situation, there has been proposed a method of adding a substance having the following characteristics to this kind of polymer photosensitive material (Japanese Patent Laid-Open No. Hei 8-248561).
No.). That is, the characteristic is that the acid generated by the photoreaction generates the acid by itself and multiplies the acid autocatalytically. Such a substance having an acid multiplying function will be referred to as an acid multiplying agent here. If this reaction occurs in a chain, the generation of acid will increase in a mouse. If an acid multiplying agent having such properties is added, the acid rapidly increases, so that the stop of the acid catalyzed reaction by the basic substance can be prevented, the disappearance of the acid by the side reaction can be prevented, and further, the acid catalyzed reaction can be prevented. Can be greatly accelerated.

[0007]

It has been reported that the sensitivity can be improved by adding an acid multiplying agent to a conventional chemically amplified photoresist. However, higher performance and higher sensitivity have been reported. Was desired. The present invention has been made with a view to fundamentally solving such a problem. A first object of the present invention is to provide an acid-sensitive resin used for a chemically amplified photoresist having high performance and high sensitivity. A second object of the present invention is to provide a high-sensitivity resin comprising the acid-sensitive resin. It is an object of the present invention to provide a resin composition for an active energy ray having high performance and high sensitivity, and a third object of the present invention is to provide a pattern forming method using the resin composition for an active energy ray.

[0008]

In a solution obtained by adding a catalytic amount of an acid to an acid multiplying agent, the acid multiplying reaction proceeds efficiently and the acid concentration increases by an amount corresponding to the acid multiplying agent (K. Ar
imitsu et al. , J. et al. Am. Chem. So
c. , 120, 37 (1998)). However, it was found that when the acid growth reaction was carried out in the resin solid, the reaction rate was significantly reduced. For this reason, the diffusion behavior of acid molecules in a resin solid has been investigated. As a result, it has been confirmed that diffusion of acid molecules functioning as a catalyst in the resin solid is greatly suppressed. That is, the process in which the acid diffuses in the acid-reactive resin and reaches the acid multiplying agent is a rate-determining step, and thus the acid multiplying reaction is not sufficiently induced. Therefore, in order to cause the acid multiplication reaction to occur efficiently in the solid resin, it is conceivable to increase the concentration of the acid multiplication agent as much as possible.

[0009] Since the conventional acid proliferating agent has a low molecular weight and does not have a self-supporting property by itself, a method of adding it to an acid-reactive resin having film forming properties has been adopted (Kyohei Hei 8-2).
No. 48561). In this method, the glass transition temperature of the acid-reactive resin having a film-forming property is remarkably reduced when a large amount of the low-molecular acid proliferating agent is added, so that the amount added is limited. Therefore, a molecular group having an acid amplifying ability to generate an acid by the action of an acid, that is, an acid amplifying group is bonded to the resin itself, thereby retaining the acid amplifying ability and imparting a film forming property to itself. I thought. The present invention has been completed as a result of intensive studies based on such considerations.

[0010] In order to solve the above-mentioned problems of the prior art, a first aspect of the present invention is to provide a 2-hydroxybicycloalkane represented by the following general formula (1) having the ability to generate an acid by the action of an acid. A vinyl acid-sensitive resin characterized by having a 1-sulfonate residue in a side chain.

[0011]

Embedded image

(Wherein R ₁ is a hydrogen atom or a methyl group,
R ₂ is a hydrogen atom or a methyl group, m + n is 2, m
Represents 1 or 2)

According to a second aspect of the present invention, there is provided the acid-sensitive resin according to the first aspect, wherein the acid-sensitive resin is represented by the following general formula (2):
It is characterized by containing a vinyl polymerizable monomer unit having a hydroxybicycloalkane-1-sulfonate residue and a vinyl polymerizable monomer unit that generates a carboxyl group by a deprotection reaction with an acid.

[0014]

Embedded image

(Wherein R ₁ is a hydrogen atom or a methyl group,
R ₂ is a hydrogen atom or a methyl group, R ₃ is nothing or a divalent residue, m + n is 2, m is 1 or 2
Indicates)

According to a third aspect of the present invention, there is provided an active energy ray resin composition comprising the acid sensitive resin according to the first or second aspect and a substance which generates an acid by an active energy ray. .

According to a fourth aspect of the present invention, there is provided an acid-sensitive resin according to the first or second aspect, a substance capable of generating an acid by an active energy ray, and an acid proliferating agent capable of generating an acid by the action of an acid. An active energy ray resin composition comprising:

According to a fifth aspect of the present invention, there is provided a pattern forming method using the active energy ray resin composition according to the third or fourth aspect.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. A 2-hydroxybicycloalkane-1-sulfonate represented by the following general formula (3), which is a model compound of the acid-proliferative residue represented by the general formula (1) according to claim 1 of the present invention, comprises: , cause pinacol type transfer reaction in the presence of an acid to generate an acid (Y-SO ₂ 0H).

[0020]

Embedded image

[0021] (Formula (3) in, R _1, R _2, m, n are the same as R _1, R _2, m, n in the general formula (1),
Y represents an alkyl group, a phenyl group, or a substituted phenyl group)

[0022] In order to have sufficient acid strength to cause transfer reaction of the acid (Y-SO ₂ 0H) itself hydroxy bicycloalkane-1-sulfonates, autocatalytic reactions, i.e. Excessive acid growth reaction. In the absence of p-toluenesulfonic acid, no reaction occurs, but in the presence, decomposition occurs after an induction period, and the time change of the reaction becomes a sigmoidal curve, confirming that the reaction is autocatalytic. it can.

In the acid-sensitive resin of the present invention, a sulfonic acid residue is formed on the resin by an acid-catalyzed reaction, so that the solubility in a polar solvent or an alkaline aqueous solution is improved. Further, the bicycloalkyl group also has a feature that it is superior in oxygen plasma etching resistance as compared with a single-chain alkyl group. The acid-sensitive resin of the present invention can be produced by radical polymerization of an acid-proliferating monomer represented by the following general formula (4).

[0024]

Embedded image

(In the general formula (4), R ₁ , R ₂ , R ₃ ,
m and n are R ₁ in the general formulas (1) and (2),
The same as R ₂ , R ₃ , m and n, and R ₄ represents a hydrogen atom or a methyl group)

FIG. 1 shows an example of the acid-proliferating monomer suitably used in the present invention, but the acid-proliferating monomer used in the present invention is not limited to these. They are,
It can be produced by selectively monosulfonating the corresponding 1,2-diol.

The acid-sensitive resin of the present invention can be produced not only by homopolymerization of the acid-proliferating monomer represented by the above formula (4) but also by copolymerization with another radically polymerizable monomer.

The copolymerizable monomers include hydrophilic monomers such as maleic anhydride, p-hydroxystyrene, acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate, and the hydrophobic monomers include adamantyl acrylate. , Adamantyl methacrylate, phenyl acrylate, phenyl methacrylate and the like can be used.

In the case of a monomer having a large hydrophobicity, it is necessary to keep the copolymerization ratio of the acid-proliferating monomer represented by the general formula (4) to at least 0.3 or more. If the copolymerization ratio is less than this, the resin after decomposition with an acid is not preferred because the solubility in a polar solvent or an aqueous alkali solution is significantly reduced.

The acid-sensitive resin according to the second aspect of the present invention comprises a vinyl polymerizable monomer unit having a 2-hydroxybicycloalkane-1-sulfonate residue represented by the above general formula (1), and a depolymerization by an acid. It comprises a vinyl polymerizable acid-reactive monomer unit that generates a carboxyl group by a protection reaction. As the vinyl polymerizable acid-reactive monomer suitably used in the present invention, a known acrylate or methacrylate which causes an acid-catalyzed deprotection reaction, and further, a polycyclic aliphatic monomer having a radically polymerizable ethylene group may be used. Can be.

FIG. 2 illustrates these vinyl-polymerizable acid-reactive monomers. The copolymerization ratio of the acid-proliferating monomer and the vinyl polymerizable acid-reactive monomer is 0.05 to 0.80 and 0.3 to 0.95, more preferably 0.10 to 0.6.
0 and ranges from 0.40 to 0.90. If the copolymerizability of the acid-proliferating monomer is less than this, no improvement in sensitivity as an active energy ray resin is observed, and no further increase in sensitivity is observed at a copolymerization ratio exceeding this range.

Further, in addition to these monomers, hydrophilic monomers such as maleic anhydride, acrylic acid and methacrylic acid can be copolymerized.

The active energy ray resin composition according to the third aspect of the present invention is obtained by adding an acid generator which generates a strong acid by the action of active energy rays to the above-mentioned acid-sensitive resin. . Although many acid generators are known, as an acid generator that generates an acid by the action of light,
A photo-acid generator used for chemically amplified photoresist and cationic photopolymerization is used (see “Organic Materials for Imaging”, edited by Research Institute for Organic Electronics Materials, Bunshin Publishing (1993), pp. 187-192).

Examples of compounds suitable for the present invention are shown below. In order to expand the photosensitive wavelength range of these photoacid generators, a photosensitizer can be appropriately used. The acid generated by the photolysis of these substances acts on the acid multiplying agent together with the photoreactive substance to promote the generation of the acid. FIG. 3 illustrates the photoacid generator used in the present invention.

These acid generators are mixed in an amount of 1 to 30 parts by weight, preferably 2 to 15 parts by weight, based on 100 parts by weight of the acid-sensitive resin.
If the amount is less than 1 part by weight, practical sensitivity cannot be obtained and 3
If the addition amount exceeds 0 parts by weight, image formation becomes difficult because the acid generator itself has a great effect on the solubility of the resin.

The active energy ray-sensitive resin composition according to claim 4 of the present invention comprises an acid generator which generates a strong acid by the action of the above-described acid-sensitive resin and the active energy ray.
Further, an acid proliferating agent which generates a new acid by the action of an acid is added. The addition of the acid proliferating agent further enhances the acid proliferating reaction, thereby improving the sensitivity.

FIG. 4 shows an acid multiplying agent suitably used in the present invention.
Shown in The amount of addition of these acid proliferating agents depends on the acid-sensitive resin 1
1 part by weight to 30 parts by weight, particularly preferably 2 parts by weight to 20 parts by weight with respect to 00 parts by weight. If the amount is less than 1 part by weight, no improvement in sensitivity due to the addition of the acid proliferating agent is observed.

The pattern formation using the active energy ray resin composition of the present invention is performed as follows. The active energy ray resin composition of the present invention is dissolved in a solvent to form a uniform solution, and impurities are removed by an appropriate method such as filtration. Next, this solution is applied to the substrate surface in a conventional manner to form a thin film, the solvent is removed by a pre-baking heat treatment, and pattern exposure is performed to generate an acid. Then
A heating (post-bake) treatment is performed to promote the chain decomposition of the acid proliferating agent. The conditions of the heat treatment vary depending on the exposure energy, the type of acid proliferating agent active for the acid to be used, the type of the alkali-soluble resin, and the like.
It is in the range of 50 ° C, more preferably in the range of 80 ° C to 130 ° C. The heating time is from 10 seconds to 10 minutes, more preferably from 30 seconds to 5 minutes. This is immersed in a solvent that causes a difference in solubility between the exposed part and the unexposed part and developed to obtain a pattern.

[0039]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples unless departing from the gist of the present invention. Example 1 22.9 g of 2,3-pinanediol, 16.3 g of triethylamine and 4.02 g of 4-dimethylaminopyridine were dissolved in 258 ml of dichloromethane, and p-styrenesulfonyl chloride 30 dissolved in 110 ml of dichloromethane was added to this solution. 0.0 g of the solution was slowly added dropwise. After stirring at room temperature for 24 hours, the solution was neutralized with dilute hydrochloric acid to remove the aqueous layer. The organic layer was washed with an aqueous solution of saturated sodium bicarbonate, washed with saturated saline, and then dried over anhydrous magnesium sulfate. The oily residue obtained by distilling off the solvent was purified by silica gel column chromatography,
21.1 g of 2-hydroxy-3- (p-styrenesulfonyloxy) pinane (A-1 in FIG. 1) was obtained. 1.05 g of 2-hydroxy-3- (p-styrenesulfonyloxy) pinane thus obtained and 9 mg of azobisisobutyronitrile were dissolved in 10.5 ml of THF, and after degassing and sealing, the mixture was reacted at 67 ° C. for 14 hours. Was. The polymerization solution was poured into petroleum ether to precipitate the resin, which was collected by filtration, dried in vacuo, and 0.69 g of the vinyl acid-sensitive resin of the present invention (Mw = 18,000, Mw / Mn = 5. 9) was obtained.

Example 2 The 2-hydroxy-3- (p-styrenesulfonyloxy) pinane and tert-butyl methacrylate obtained in Example 1 were dissolved in THF at a molar ratio of 50:50. A radical polymerization reaction was performed under the same conditions. The polymer was separated by precipitation in petroleum ether and dried in vacuo. The monomer molar ratio of the obtained vinyl acid-sensitive resin of the present invention was determined by NMR spectrum to be 42:58. The obtained vinyl acid-sensitive resin of the present invention is dissolved in cyclohexanone to form a 10 wt% solution, and diphenyl- (4-phenylthiophenyl) sulfonium hexafluoroantimonate as a photoacid generator is added to the resin in an amount of 5 wt%. % Was added. This solution is spin-coated on a silicon wafer,
A pre-bake treatment was performed at 100 ° C. for 1 minute. Xe
Irradiating light of 313 nm from a Hg lamp at 100 ° C.
And then developed with a 2.5 wt% aqueous solution of tetramethylammonium hydroxide, washed with water for 20 seconds, dried, and the film thickness was measured. As a result, 2.5m
It was completely dissolved at an exposure dose of J / cm.

(Embodiment 3) As in Embodiment 2, 16: 8
By radical polymerization of 2-hydroxy-3- (p-styrenesulfonyloxy) pinane and tert-butyl methacrylate in a molar ratio of 4, a vinyl acid-sensitive resin of the present invention having a molar ratio of 10:90 was obtained. As a photoacid generator, diphenyl- (4-
Example 2 (5% by weight of phenylthiophenyl) sulfonium hexafluoroantimonate was added to the resin.
Exposure was performed in the same manner as described above.
It was completely dissolved in a 2.5 wt% aqueous solution of tetramethylammonium hydroxide at an exposure dose of m ² .

Example 4 Diphenyl- (4-phenylthiophenyl) sulfonium hexafluoroantimonate as a photoacid generator was added to the cyclohexane solution of the vinyl acid-sensitive resin of the present invention obtained in Example 2 with respect to the resin. 5
wt%, and 2-hydroxy-3-octanesulfonyloxypinane, which is an acid proliferating agent, was added to the resin at 5 wt%, 10 wt%, and 20 wt%. These solutions are spin-coated on a silicon wafer and 313 nm
When exposed to light of 0.9 mJ / cm, respectively.
² , and completely dissolved at 0.9 mJ / cm ² and 0.3 mJ / em ² .

(Example 5) Diphenyl- (4-phenylthiophenyl) sulfonium hexafluoroantimonate as a photoacid generator was added to the cyclohexane solution of the vinyl acid-sensitive resin of the present invention obtained in Example 3 using the resin. 5 for
5%, 10% and 20% by weight of 2-hydroxy-3-octanesulfonyloxypinane, which is an acid enriching agent, was added to the resin. These solutions are spin-coated on a silicon wafer and 313 nm
Exposure to 0.5 mJ / cm
² , completely dissolved at 0.4 mJ / cm ² and 0.1 mJ / cm ² .

Example 6 The active energy ray-sensitive resin composition of the present invention prepared in Example 5 was spin-coated on a silicon wafer, prebaked, and then dried through a photomask.
Light was irradiated to 13 nm. After the irradiation, post-baking was performed at 100 ° C. for 1 minute, and development was performed with a 2.5 wt% aqueous solution of tetramethylammonium hydroxide. As a result, a clear positive image was obtained.

[0045]

In the vinyl acid-sensitive resin according to the first aspect of the present invention, since a sulfonic acid residue is formed on the resin by an acid catalyzed reaction, the solubility in a polar solvent or an aqueous alkali solution is improved. Further, a bicycloalkyl group is more excellent in oxygen plasma etching resistance than a single-chain alkyl group. Since the sensitivity of the chemically amplified photosensitive material is improved, it can be used as a high-sensitivity pattern forming material. Since the amount of generated acid is greatly increased by the acid propagating group, the neutralizing effect of the photogenerated acid by the basic substance existing in the environment can be reduced. Therefore, a good relief pattern is formed.

The vinyl acid-sensitive resin according to the second aspect of the present invention has much higher sensitivity.

The active energy ray resin composition according to the third aspect of the present invention is obtained by adding an acid generator which generates a strong acid by the action of active energy rays to a vinyl acid-sensitive resin. The acid generated by the decomposition acts on the acid multiplying agent together with the photoreactive substance to promote the generation of the acid, thereby improving the sensitivity.

The active energy ray-sensitive resin composition according to claim 4 of the present invention is a vinyl acid-sensitive resin, a substance capable of generating an acid by an active energy ray, and an acid capable of generating an acid by the action of an acid and having an acid-proliferating ability. It consists of a proliferating agent, and the sensitivity is further improved by adding an acid proliferating agent.

According to the pattern forming method of the present invention, a pattern can be easily formed with high sensitivity on the substrate surface.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a molecular structure of an example of an acid-proliferating monomer suitably used in the present invention.

FIG. 2 (B-1) to (B-20) are explanatory diagrams showing the molecular structures of examples of a vinyl polymerizable acid-reactive monomer suitably used in the present invention.

FIGS. 3 (C-1) to (C-11) are explanatory views showing the molecular structures of examples of a photoacid generator suitably used in the present invention.

FIG. 4 is an explanatory diagram showing a molecular structure of an example of an acid proliferating agent suitably used in the present invention.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H025 AA01 AA02 AB16 AC01 AD03 BE00 BE10 BG00 CB14 CB41 CB45 FA12 4J100 AB07P AL04Q AL08Q AL19Q BA03P BA11Q BA12Q BA51Q BA55P BC02P BC02Q BC03Q BC04Q BC33Q CA01 JA04

Claims (5)

[Claims] 1. A side chain comprising a 2-hydroxybicycloalkane-1-sulfonate residue represented by the following general formula (1) having an acid-proliferating ability to generate an acid by the action of an acid. Vinyl acid-sensitive resin. Embedded image (Wherein R ₁ is a hydrogen atom or a methyl group, R ₂ is a hydrogen atom or a methyl group, m + n is 2, m is 1 or 2
Indicates) 2. A vinyl polymerizable monomer unit having a 2-hydroxybicycloalkane-1-sulfonate residue represented by the following general formula (2), and a vinyl polymerizable monomer which generates a carboxyl group by a deprotection reaction with an acid. 2. The acid-sensitive resin according to claim 1, comprising units. Embedded image (Wherein, R ₁ is a hydrogen atom or a methyl group, R ₂ is a hydrogen atom or a methyl group, R ₃ is nothing or a divalent residue, m + n is 2, and m represents 1 or 2) ) 3. An active energy ray resin composition comprising the acid-sensitive resin according to claim 1 and a substance generating an acid by active energy rays. 4. An acid-sensitive resin according to claim 1 or 2, comprising a substance capable of generating an acid by an active energy ray and an acid proliferating agent capable of generating an acid by the action of an acid. Characteristic active energy ray resin composition. 5. A method for forming a pattern, comprising using the active energy ray resin composition according to claim 3 or 4.