JPH09211866A - Chemical amplification positive type resist material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resist material having high sensitivity to high energy beams such as far UV, electron beams or X-rays, capable of forming a pattern by development with an aq. alkali soln. and fit for a fine working technique. SOLUTION: This resist material contains an org. solvent, a high molecular compd. having a wt. average mol.wt. of 3,000-300,000 represented by the formula, an acid generating agent and a dissolution controlling agent. In the formula, R<1> is H or CH3 , each of R<2> and R<3> is an acid-unstable group, 0.02<=p(p+q+r)<=0.5, 0.01<=q/(p+q+r)<=0.3, 0<(p+q)/(p+q+r)<=0.8 and (a) is 1-3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable for fine processing technology which has high sensitivity to high energy rays such as far ultraviolet rays, electron beams and X-rays, and can form a pattern by developing with an alkaline aqueous solution. The present invention relates to a chemically amplified positive resist material.

[0002]

2. Description of the Related Art In recent years,
Along with the high integration and high speed of LSIs, the miniaturization of pattern rules is required, and in the photoexposure currently used as a general-purpose technique, the essential resolution limit derived from the wavelength of the light source is approached. It's starting. In photoexposure using a g-line (436 nm) or an i-line (365 nm) as a light source, the pattern rule of about 0.5 μm is the limit, and the integration degree of an LSI manufactured using this is 16 Mbit D
Up to RAM equivalent. However, LSI prototypes have already been made at this stage, and there is an urgent need to develop further miniaturization techniques.

[0003] Against this background, far-ultraviolet lithography is expected as a next-generation microfabrication technology. The deep-UV lithography is capable of processing 0.3 μm or less, and when a resist material having low light absorption is used, it becomes possible to form a pattern having a side wall that is nearly vertical to the substrate.

A recently developed acid-catalyzed chemically amplified positive resist material (Japanese Patent Publication No. 2-27660,
3-27829, etc.) uses a high-intensity KrF excimer laser as a light source for far-ultraviolet rays, and is particularly promising for far-ultraviolet lithography having excellent sensitivity, resolution, and dry etching resistance. It is expected as a resist material.

As such a chemically amplified positive type resist material, a two-component system comprising an alkali-soluble base resin and an acid generator, and a three-component system comprising a base resin, an acid generator and a dissolution inhibitor having an acid labile group. Ingredient systems are known.

For example, Japanese Laid-Open Patent Publication No. 62-115440 proposes a resist material comprising poly-p-tert-butoxystyrene and an acid generator, and Japanese Patent Laid-Open Publication No. 3-223858 discloses a resist material similar to this proposal. T in the molecule
A two-component resist material comprising an ert-butoxy group-containing resin and an acid generator, and further, JP-A-4-21158 discloses a methyl group, an isopropyl group, a tert-butyl group, a tetrahydropyranyl group, and a trimethylsilyl group-containing poly. A two-component resist material composed of hydroxystyrene and an acid generator has been proposed.

Further, JP-A-6-100488 discloses poly [3,4-bis (2-tetrahydropyranyloxy) styrene], poly [3,4-bis (tert-butoxycarbonyloxy) styrene], poly A resist material comprising a polydihydroxystyrene derivative such as [3,5-bis (2-tetrahydropyranyloxy) styrene] and an acid generator has been proposed.

However, the base resin of these resist materials has a single acid labile group, and the acid labile group is decomposed by a strong acid such as tert-butyl group and tert-butoxycarbonyl group. Then, the pattern shape of the resist material is likely to be a T-top shape, and on the other hand, an alkoxyalkyl group such as an ethoxyethyl group is decomposed by a weak acid. Therefore, with the passage of time from exposure to heat treatment, There are problems that the pattern shape is extremely thin, and that sensitivity and resolution are not satisfactory, and all of them have problems, and it is the current situation that they have not been put to practical use, and improvement of these problems is desired. .

The present invention has been made in view of the above circumstances,
An object of the present invention is to provide a chemically amplified positive resist material having high sensitivity and resolution, exposure margin, and process adaptability, which are higher than those of conventional resist materials when added to a resist material as a base resin.

[0010]

Means for Solving the Problems and Modes for Carrying Out the Invention As a result of extensive studies conducted by the present inventor to achieve the above-mentioned object, the repeating unit represented by the following general formula (1) obtained by the method described below was selected. Having a weight average molecular weight of 3,000 to
300,000 polymer compounds are effective as the base resin of the chemically amplified positive resist material, and the chemically amplified positive resist material containing the polymer compound, the acid generator and the organic solvent, and more preferably further dissolved therein. A chemically amplified positive resist material containing a control agent enhances the dissolution contrast of the resist film, especially the dissolution rate after exposure, and has high resolution, exposure margin, and process adaptability, and is highly practical. It has been found that it is advantageous for precise microfabrication and is very effective as a resist material for VLSI.

[0011]

Embedded image (However, in the formula, R ¹ is a hydrogen atom or a methyl group, and R ² ,
R ³ is an acid labile group different from each other. p, q, and r are positive numbers, and 0.02 ≦ p / (p + q + r) ≦ 0.5, 0.0
1 ≦ q / (p + q + r) ≦ 0.3, 0 <(p + q) /
It is a number that satisfies (p + q + r) ≦ 0.8. a is 1
It is a positive number of 3. )

Here, in the polymer compound of the general formula (1), a part of the phenolic hydroxyl group is protected by two types of acid labile groups. When such a polymer compound is used as a base resin in a resist material, especially 2
As a heterogeneous acid labile group of various types, R ² is represented by the above general formula (2).
An alkoxyalkyl group such as an ethoxyethyl group, an ethoxypropyl group, a butoxyethyl group and the like, R
^{When 3} is a group having a carbonyl group such as a tert-butoxycarbonyl group (t-BOC group) represented by the following general formula (3), a tetrahydropyranyl group, a tetrahydrofuranyl group or a trialkylsilyl group, its resist The material has the advantages as a resist material that each acid labile group has, such as alkali dissolution inhibition by an acid labile group such as a carbonyl group of R ⁵ and ease of elimination by an alkoxyalkyl group of R ^{4 and} the like. The drawbacks that result when the stabilizing group is introduced alone can be complemented with each other.

[0013]

Embedded image (However, in the formula, R ⁴ and R ⁵ are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms,
R ⁶ is a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms. R ⁷ is a linear or branched alkyl group having 1 to 6 carbon atoms, and b is 0 or 1. )

That is, when the alkoxyalkyl group represented by the general formula (2) alone is used, it is difficult to form a T-top shape because the elimination reaction proceeds with a weak acid, but as described above, the T-top shape does not occur. Due to its sensitivity, the pattern shape remarkably narrows with the lapse of time from exposure to heat treatment, and its dissolution inhibiting effect on alkali is low, so a high substitution rate material must be used to obtain dissolution contrast. However, it has a drawback that it lacks heat resistance.

On the other hand, when the phenolic hydroxyl group of the above-mentioned polymer compound is protected by, for example, only t-BOC group and is blended in the resist material, the alkali dissolution inhibiting property is good, and the dissolution contrast can be obtained at a low substitution rate. Although it has the advantage of good heat resistance, it is necessary to allow the presence of a strong acid such as trifluoromethanesulfonic acid in order to eliminate it and make it alkali-soluble. In addition, it has a drawback that it tends to have a T-top shape.

In contrast to such a polymer compound, a resist material using a polymer compound in which a phenolic hydroxyl group is protected by two kinds of acid labile groups having different properties as described above is used. Complement each other's drawbacks without losing their advantages.

Further, when a dissolution control agent is added, the dissolution contrast of the resist film is enhanced, and especially the dissolution rate after exposure is increased. That is, when the above dissolution control agent is added,
By being well compatible with the base resin of the general formula (1) and the acid generator, increasing the dispersibility of the acid generator, densifying the matrix, and evenly controlling the migration of the acid generated after exposure, Improves image quality and rectangularity. Further, in the patterning process of exposure, heating, and development, the dissolution rate of the alkali-soluble resin that is the matrix is suppressed in the unexposed area, and the acid labile groups of the alkali-soluble resin that is the matrix are decomposed in the exposed area. Therefore, the dissolution rate in the alkaline aqueous solution is promoted, the permeation of the alkaline aqueous solution into the film is increased, and the dissolution control agent is rapidly dissolved to block the alkali-soluble resin that is not yet sufficiently dissolved. Apparent alkali dissolution rapidly increases due to release into the alkaline aqueous solution.

From these facts, the chemically amplified positive resist material using the polymer compound of the general formula (1) as a base resin is apt to have a T-top shape, the pattern shape is thin, and the heat resistance is lacking. It has much less problems than conventional ones, and as a result has high sensitivity and high resolution,
Further, the inventors have found that a chemically amplified positive resist material having excellent process adaptability can be achieved by arbitrarily controlling pattern dimensions and pattern shape depending on the composition, and thus the present invention has been accomplished. Is.

Therefore, the present invention has (I) (A) an organic solvent (B) as a base resin, which has a repeating unit represented by the following general formula (1) and has a weight average molecular weight of 3,000 to 30.
Polymer compound (C) having an amount of 10,000 (C) A chemically amplified positive resist composition containing an acid generator, and (II) further comprising (D) a dissolution control agent (I)
A chemically amplified positive resist material as described is provided.

[0020]

Embedded image (However, in the formula, R ¹ is a hydrogen atom or a methyl group, and R ² ,
R ³ is an acid labile group different from each other. p, q, and r are positive numbers, and 0.02 ≦ p / (p + q + r) ≦ 0.5, 0.0
1 ≦ q / (p + q + r) ≦ 0.3, 0 <(p + q) /
It is a number that satisfies (p + q + r) ≦ 0.8. a is 1
It is a positive number of 3. )

The present invention will be described in more detail below. The chemically amplified positive resist composition of the present invention is a resist composition containing (A) an organic solvent, (B) a base resin, and (C) an acid generator as main components. A (D) dissolution control agent is blended therein.

Here, as the organic solvent (A), (B)
Any organic solvent can dissolve the acid generator, the base resin, the dissolution control agent, and the like of the component (D). Examples of such an organic solvent include cyclohexanone and methyl-
Ketones such as 2-n-amyl ketone, alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol and 1-ethoxy-2-propanol, propylene glycol monomethyl ether, ethylene Ethers such as glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, Examples include esters such as methyl-3-methoxypropionate and ethyl-3-ethoxypropionate. It can be used alone or as a mixture of species, but is not limited thereto. In the present invention, among these organic solvents, diethylene glycol dimethyl ether and 1-ethoxy-2 which have the best solubility of the acid generator in the resist component are used.
-Propanol is preferably used.

The amount of the organic solvent used is 200 to 1,000 parts with respect to 100 parts of the base resin (parts by weight, the same applies hereinafter).
Particularly, 400 to 800 parts is preferable. If the amount is less than 200 parts, the compatibility may be deteriorated and the film formability may be deteriorated.
If it exceeds 00 parts, it becomes a thin film when a resist film is formed, and it may not be used.

The (B) base resin of the present invention is a copolymer having each unit represented by the following general formula (1).

[0025]

Embedded image

In the above formula (1), R ¹ is a hydrogen atom or a methyl group. R ² and R ³ are different acid labile groups, and various acid labile groups are selected. In particular, R ² is a group represented by the following formula (2), and R ³ is A group represented by the formula (3), a tetrahydropyranyl group,
It is preferably a tetrahydrofuranyl group or a trialkylsilyl group.

[0027]

Embedded image (However, in the formula, R ⁴ and R ⁵ are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms,
R ⁶ is a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms. R ⁷ is a linear or branched alkyl group having 1 to 6 carbon atoms, and b is 0 or 1. )

Examples of the linear or branched alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an iso-butyl group, a tert-butyl group, and the like. A cyclohexyl group etc. can be illustrated as an alkyl group.

Specific examples of the acid labile group represented by the above formula (2) include methoxyethyl group, ethoxyethyl group, n-propoxyethyl group, iso-propoxyethyl group and n-butoxy group. Ethyl group, iso-butoxyethyl group, tert-butoxyethyl group, cyclohexyloxyethyl group, methoxypropyl group, ethoxypropyl group, 1-methoxy-1-methyl-ethyl group, 1-
Examples thereof include an ethoxy-1-methyl-ethyl group, and examples of the acid labile group of the above formula (3) include a tert-butoxycarbonyl group and a tert-butoxycarbonylmethyl group. Examples of the trialkylsilyl group include those having 1 to 6 carbon atoms in each alkyl group such as trimethylsilyl group and tri-tert-butyldimethylsilyl group. Among these, considering the characteristics of the resist material in which the polymer compound of the present invention is used as the base resin, 2 of the polymer compounds represented by the above formula (1) are considered.
Examples of the acid labile group include an alkoxyalkyl group represented by the above formula (2) as R ² and a tert-group as R ^3.
It is desirable to combine it with a butoxycarbonyl group.

Further, p, q, and r are positive numbers, respectively.
02 ≦ p / (p + q + r) ≦ 0.5, preferably 0.0
4 ≦ p / (p + q + r) ≦ 0.4, 0.01 ≦ q / (p
+ Q + r) ≦ 0.3, preferably 0.05 ≦ q / (p +
q + r) ≦ 0.25, 0 <(p + q) / (p + q + r)
≦ 0.8, preferably 0.07 ≦ (p + q) / (p + q
+ R) ≦ 0.5. When any of p, q, and r becomes 0 and the polymer compound of the above formula (1) has a structure not containing any unit, the contrast of the alkali dissolution rate decreases and the resolution deteriorates. When the ratio of p to the whole (p + q + r, the same applies below) is less than 0.02 and the ratio of q to the whole is less than 0.01, it is not possible to bring out the merits of each acid labile group, and the ratio of p to the whole is low. Exceeds 0.5, p and q
When the total ratio of the total amount of and is more than 0.8, the glass transition temperature of the polymer compound is lowered, the heat resistance is deteriorated, and the change in film thickness or the generation of film stress or bubbles during alkali development may occur. In some cases, since the hydrophilic group is reduced, the adhesion to the substrate may be poor. Furthermore, by appropriately selecting the values of p, q, and r within the above range, it is possible to arbitrarily control the pattern size and the pattern shape. In addition, a of the said Formula (1) is a positive number of 1-3.

In the base resin of the present invention, the content of the acid labile group affects the contrast of the dissolution rate of the resist film and is related to the characteristics of the resist material such as pattern size control and pattern shape.

The base resins of the present invention each have a weight average molecular weight (measurement method is as described below) of 3,000 to
300,000, preferably 3,000 to 30,000
Needs to be If the weight average molecular weight is less than 3,000, the resist material will be inferior in heat resistance.
If it exceeds 50,000, the alkali solubility is lowered, and the trailing phenomenon is likely to occur after pattern formation.

Further, in the base resin of the present invention, when the molecular weight distribution (Mw / Mn) is wide, there are low molecular weight and high molecular weight polymers, and when there are many low molecular weight polymers, the heat resistance may deteriorate. If a large amount of high-molecular weight polymer is present, it may include a substance that is difficult to dissolve in an alkali, which may cause skirting after pattern formation. Therefore, as the pattern rule becomes finer, the influence of such a molecular weight and the molecular weight distribution is likely to become large. Therefore, in order to obtain a resist material suitable for a fine pattern dimension, the base resin has a molecular weight distribution of 1. 0 to
The monodispersion is preferably 1.5, particularly 1.0 to 1.3.

The base resin of the present invention can be produced by using a monomer of the following formula according to a conventional radical polymerization method.

[0035]

Embedded image (However, in the formula, R ¹ , R ² , R ³ and a have the same meanings as described above.)

Further, when it is applied to a resist material having a fine pattern rule, a monodisperse polymer compound is preferable for the above reason, and in order to obtain a monodisperse polymer compound, the above radical is used. The polymer with a broad molecular weight distribution polymerized by polymerization is fractionated to obtain a molecular weight distribution of 1.
Monodispersion is obtained by obtaining 0 to 1.5.

Specifically, first, radical polymerization of the monomer of the above formula is carried out by a usual method using a polymerization initiator. In this case, as the polymerization initiator, those usually used can be used in a usual amount, but an organic peroxide, particularly an organic peroxide having a 10-hour half-life of 40 ° C to 90 ° C (for example, lauroyl). Peroxide and the like) are more preferably used.

The radical polymerization is preferably carried out in an organic solvent. Specific examples of the organic solvent used include aromatic hydrocarbons, cyclic ethers, and aliphatic hydrocarbon solvents (for example, benzene, toluene, tetrahydrofuran (THF), dioxane, tetrahydropyran, dimethoxyethane, n-hexane, cyclohexane, etc.) Although these mixed solvents are mentioned, it is particularly preferable to use acetone. The amount of the organic solvent used is usually preferably 10 to 50% by weight in terms of monomer concentration.

The radical polymerization conditions can be adjusted appropriately, but it is preferable to carry out the reaction for 3 to 10 hours at a temperature 20 to 50 ° C. higher than the 10-hour half-life of the organic peroxide.

Further, the polymer compound of the present invention is obtained by radical-polymerizing or addition-polymerizing (living anion polymerization) a monomer represented by the following structural formula (4), and then hydrolyzing the resulting hydroxyl group. It can be prepared, for example, by protection by a chemical reaction with a first acid labile group of the above formula (2) and a second acid labile group of the above formula (3).

[0041]

Embedded image (However, in the formula, R ¹ has the same meaning as above.)

Here, in order to obtain a monodispersed polymer compound, generally, in addition to the method of monodispersion by radical polymerization using each of the above-mentioned monomers, the method of monodispersion by addition polymerization is adopted. However, since the former method of monodispersion complicates the process, the latter method of monodispersion by addition polymerization is preferably used. However, since some of the copolymers cannot undergo addition polymerization, radical polymerization is also suitably used for some copolymers.

When the base resin of the present invention is produced by radical polymerization using the monomer of the above formula (4), it can be carried out in the same manner as the above radical polymerization.

On the other hand, when the base resin of the present invention is produced by living anionic polymerization using the monomer of the above formula (4), it can be carried out by using a known living anionic polymerization initiator. In order to obtain the polymer compound, it is preferable to use an organometallic compound among living anion polymerization initiators. Examples of the organometallic compound include organic alkali metals such as n-butyllithium, sec-butyllithium, tert-butyllithium, sodium naphthalene, naphthalene potassium, anthracene sodium, α-methylstyrene tetramerge sodium, cumyl potassium, cumyl cesium, and the like. No. The amount of living anionic polymerization initiator added is the designed molecular weight (= monomer weight / mol of initiator).
Calculated from the relationship.

Living anionic polymerization of the above monomers is
It is generally carried out in an organic solvent. Examples of the organic solvent to be used include the same solvents as in the case of the radical polymerization, and it is particularly preferable to use tetrahydrofuran.

The concentration of the monomer used for the polymerization is appropriately 1 to 30% by weight, and the reaction is preferably carried out under high vacuum or in an atmosphere of an inert gas such as argon or nitrogen with stirring. The reaction temperature can be freely selected from −78 ° C. to the boiling temperature of the reaction solution used, but in particular, a tetrahydrofuran solvent is −78 ° C. to 0 ° C., and a room temperature is preferable when a benzene solvent is used.

The polymerization reaction can be carried out for about 10 minutes to 7 hours, and a polymer having a repeating unit represented by the following general formula (5) can be obtained by this reaction. The polymerization reaction can be stopped by adding a stopping agent such as methanol, water or methyl bromide to the reaction system.

[0048]

Embedded image (However, in the formula, R ¹ has the same meaning as above.)

In the above living anionic polymerization reaction, 100% of the monomers react and the molecular weight can be adjusted appropriately, so that the molecular weight distribution of the obtained polymer is monodisperse (Mw).
/Mn=1.0 to 1.5).

Here, the weight average molecular weight (Mw)
Can be easily calculated from the weight of the monomer used and the number of moles (number of molecules) of the initiator, and can be measured by the light scattering method. The number average molecular weight (Mn) can be measured using a membrane osmometer. Furthermore, the molecular structure is infrared absorption (IR)
It can be easily confirmed by the spectrum and ¹ H-NMR spectrum, and the molecular weight distribution can be evaluated by gel permeation chromatography (GPC).

Further, in the present invention, it is obtained by the above method and preferably has a weight average molecular weight of 3,000 to 300,
000, the tert-butyl group of the polymer of the above formula (5) having a molecular weight distribution of 1.0 to 1.5 is hydrolyzed to obtain polyhydroxystyrenes represented by the following formula,
As shown in the following formula, a part of the hydroxyl groups generated by hydrolysis is sequentially protected by the acid labile groups represented by R ² and R ³ to obtain the desired monodisperse (that is, the molecular weight distribution is 1.
0 to 1.5) and the weight average molecular weight (that is, 3,
000 to 300,000) can be obtained.

[0052]

Embedded image (However, in the formula, R ¹ , R ² , R ³ , p, q, and r have the same meanings as described above.)

That is, in the compound of the above formula (5), when the tert-butyl group, which is a protective group for the hydroxyl group, is hydrolyzed, hydrochloric acid, odor, etc. are added in a mixed solvent of dioxane, acetone, acetonitrile, benzene, water and the like. It can be easily carried out by dropping an appropriate amount of acid such as hydrofluoric acid. According to such a method, the main chain of the polymer compound is not cleaved during the reaction and a cross-linking reaction does not occur between the molecules, so that the polyhydroxystyrene derivative having a hydroxyl group whose molecular weight distribution is easily controlled. Can be obtained.

The protection by the acid labile groups R ² and R ³ is
After removing the hydroxyl-protecting group by hydrolysis as described above, the acid labile groups R ² and R ³ can be introduced by a chemical reaction.

This reaction is particularly effective for obtaining a polymer compound in which R ² is an alkoxyalkyl group. This alkoxyalkylation reaction is carried out by adding a hydrogen atom of a hydroxyl group of polyhydroxystyrene of the above formula to a vinyl group of an ether compound represented by the following formula using an acid as a catalyst to give a hydroxyl group of polyhydroxystyrene as shown by the following formula. A part (ratio of p mol to 1 mol of all hydroxyl groups) is protected with an alkoxyalkyl group.

[0056]

Embedded image (However, in the formula, R ¹ , R ⁴ , and R ⁶ have the same meanings as described above, and R ⁵¹ is a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms.)

Here, examples of the ether compound include vinyl ether, propenyl ether and the like. This reaction is preferably carried out in the presence of a solvent such as dimethylformamide, tetrahydrofuran, dimethylacetamide, and the acid is hydrochloric acid, sulfuric acid, p-
Toluenesulfonic acid, methanesulfonic acid, p-toluenesulfonic acid pyridinium salt and the like are used, and the amount thereof is preferably 0.1 to 10 mol% with respect to 1 mol of all hydroxyl groups of polyhydroxystyrene to be reacted. The reaction temperature is preferably room temperature to 60 ° C., and the reaction time is usually 1 to 20.
Time.

When part of the hydroxyl groups of the polyhydroxystyrene is methoxymethylated, Na is added in the presence of a solvent such as dimethyl sulfoxide or tetrahydrofuran.
It is preferable to react polyhydroxystyrene with an alkali hydride such as H and a halomethyl ether such as chloromethyl ether. In this case, it is preferable that the amount of alkali hydride used is such that a predetermined methoxymethyl group is introduced with respect to 1 mol of all hydroxyl groups of polyhydroxystyrene that reacts. The reaction temperature is preferably 0 to 50 ° C., and the reaction time is usually 1 to 20 hours.

After carrying out the alkoxyalkylation reaction in this way, a tert-butoxycarbonylation reaction, a tert-butoxycarbonylmethylation reaction, etc. are carried out for the introduction of the acid labile group R ³ .

The tert-butoxycarbonylation reaction can be carried out by reacting the partially alkoxyalkylated polyhydroxystyrene with di-tert-butyl dicarbonate in a solvent such as pyridine or tetrahydrofuran. In this case, dicarbonic acid di-tert-
Butyl is the total hydroxyl group of polyhydroxystyrene of the above formula 1
It is used in an amount such that q mol of a tert-butoxycarbonyl group is introduced with respect to mol. The reaction temperature is preferably room temperature to 50 ° C., and the reaction time is usually 30 minutes to 4 hours.

Further, the tert-butoxycarbonylmethylation reaction is carried out by adding potassium-tert-butoxide and t-butoxide to the partially alkoxyalkylated polyhydroxystyrene in a solvent such as dimethyl sulfoxide or tetrahydrofuran.
It can be carried out by reacting with ert-butoxycarbonylmethyl bromide. In this case, the amount of potassium-tert-butoxide used is tert-but with respect to 1 mol of all hydroxyl groups of the polyhydroxystyrene of the above formula.
It is the amount by which q mol of butoxycarbonylmethyl group is introduced. The amount of tert-butoxycarbonylmethyl bromide used is equimolar to potassium-tert-butoxide, the reaction temperature is preferably room temperature to 50 ° C, and the reaction time is usually 20 minutes to 10 hours.

Further, the tetrahydropyranylation reaction can be carried out by reacting with dihydropyran in tetrahydrofuran, and the tetrahydrofuranylation reaction can be carried out by reacting with dihydrofuran in tetrahydrofuran. The trialkylsilylation reaction can be carried out by reaction with a trialkylsilyl chloride in the presence of imidazole. In these cases, the reaction temperature is preferably room temperature to 50 ° C., and the reaction time is usually 1 to 5 hours.

Of these, particularly in this method, tert
It is preferable to introduce a -butoxycarbonyl group or a tert-butoxycarbonylmethyl group, whereby a polymer compound represented by the following general formula can be obtained.

[0064]

Embedded image (However, in the formula, R ¹ , R ^{4 to} R ⁶ , p, q, r, and b are the same as above.)

Examples of the (C) acid generator of the chemically amplified positive resist composition of the present invention include onium salts, sulfonic acid ester derivatives, diazosulfonic acid derivatives, etc. Since it has a group such as alkoxyalkyl, the glass transition temperature (Tg) tends to be lowered, and in order to prevent this, an onium salt having a high acid generation efficiency and a large dissolution inhibiting effect is particularly preferable.

Examples of the acid generator as the component (C) include diphenyliodonium trifluoromethanesulfonate,
Trifluoromethanesulfonic acid (p-tert-butoxyphenyl) phenyliodonium, p-toluenesulfonic acid diphenyliodonium, p-toluenesulfonic acid (p-tert-butoxyphenyl) phenyliodonium, trifluoromethanesulfonic acid triphenylsulfonium, trifluoromethanesulfone Acid (p-te
rt-butoxyphenyl) diphenylsulfonium, bis (p-tert-butoxyphenyl) phenylsulfonium trifluoromethanesulfonate, tris (p-tert-butoxyphenyl) sulfonium trifluoromethanesulfonate, triphenylsulfonium p-toluenesulfonate, p- Toluenesulfonic acid (p-ter
t-butoxyphenyl) diphenylsulfonium, p-
Bis (p-tert-butoxyphenyl) phenylsulfonium toluenesulfonate, tris (p-tert-butoxyphenyl) sulfonium p-toluenesulfonate, triphenylsulfonium nonafluorobutanesulfonate, triphenylsulfonium butanesulfonate,
Trimethylsulfonium trifluoromethanesulfonate, trimethylsulfonium p-toluenesulfonate,
Cyclohexylmethyl (2-oxocyclohexyl) sulfonium trifluoromethanesulfonate, cyclohexylmethyl (2-oxocyclohexyl) sulfonium p-toluenesulfonate, dimethylphenylsulfonium trifluoromethanesulfonate, dimethylphenylsulfonium p-toluenesulfonate, trifluoromethanesulfonic acid Dicyclohexylphenylsulfonium, p-toluenesulfonic acid dicyclohexylphenylsulfonium, trifluoromethanesulfonic acid (pt
ert-butoxycarbonylmethoxyphenyl) diphenylsulfonium, trifluoromethanesulfonate tris (p-tert-butoxycarbonylmethoxyphenyl) sulfonium, bis (p-dimethylaminophenyl) trifluoromethanesulfonate (p-tert-butoxyphenyl) sulfonium, trifluoromethane Bis (p-tert-butoxyphenyl) methanesulfonate (p-
Dimethylaminophenyl) sulfonium, p-toluenesulfonic acid (p-tert-butoxycarbonylmethoxyphenyl) diphenylsulfonium, p-toluenesulfonic acid tris (p-tert-butoxycarbonylmethoxyphenyl) sulfonium, p-toluenesulfonic acid bis (p -Dimethylaminophenyl) (p-tert
-Butoxyphenyl) sulfonium, bis (p-tert-butoxyphenyl) p-toluenesulfonate (p-
Dimethylaminophenyl) sulfonium, p-toluenesulfonic acid (m-tert-butoxyphenyl) diphenylsulfonium, p-toluenesulfonic acid bis (m-)
tert-butoxyphenyl) phenylsulfonium,
Tris (m-tert-butoxyphenyl) sulfonium p-toluenesulfonate, (m-Tetrahydropyranyloxyphenyl) diphenylsulfonium p-toluenesulfonate, Bis (m-tetrahydropyranyloxyphenyl) phenylsulfonium p-toluenesulfonate , P-toluenesulfonate tris (m-tetrahydropyranyloxyphenyl) sulfonium, p-toluenesulfonate (p-tetrahydropyranyloxyphenyl) diphenylsulfonium, p-toluenesulfonate bis (p-tetrahydropyranyloxyphenyl) Phenylsulfonium, tris (p-toluenesulfonate) (p
-Tetrahydropyranyloxyphenyl) sulfonium, p-toluenesulfonic acid (p-tetrahydrofuranyloxyphenyl) diphenylsulfonium, p-toluenesulfonic acid bis (p-tetrahydrofuranyloxyphenyl) phenylsulfonium, p-toluenesulfonic acid tris (p -Tetrahydrofuranyloxyphenyl) sulfonium, pentafluorobenzenesulfonic acid (p-tert-butoxyphenyl) diphenylsulfonium, pentafluorobenzenesulfonic acid bis (p-)
tert-butoxyphenyl) phenylsulfonium,
Pentafluorobenzenesulfonic acid tris (p-ter)
t-Butoxyphenyl) sulfonium, 10-camphorsulfonic acid (p-tert-butoxyphenyl) diphenylsulfonium, 10-camphorsulfonic acid bis (p-tert-butoxyphenyl) phenylsulfonium, 10-camphorsulfonic acid tris (p-ter)
an onium salt such as t-butoxyphenyl) sulfonium,
Β-ketosulfone derivatives such as 2-cyclohexylcarbonyl-2- (p-toluenesulfonyl) propane and 2-iso-propylcarbonyl-2- (p-toluenesulfonyl) propane, bis (benzenesulfonyl) diazomethane, bis (cyclohexylsulfonyl) Diazomethane, diazomethane derivatives such as bis (tert-butylsulfonyl) diazomethane, disulfone derivatives such as diphenyldisulfone and dicyclohexyldisulfone, 2,6-dinitrobenzyl p-toluenesulfonate, and 2,4-dinitrobenzyl p-toluenesulfonate. Nitrobenzyl sulfonate derivative, 1,2,3-tris (methanesulfonyloxy) benzene, 1,2,3-tris (trifluoromethanesulfonyloxy) benzene,
1,2,3-tris (p-toluenesulfonyloxy)
Sulfonate derivatives such as benzene, phthalimido-yl-triflate, phthalimido-yl-tosylate, 5-norbornene-2,3-dicarboximide-
Imido-yl-sulfonate derivatives such as yl-triflate, 5-norbornene-2,3-dicarboximido-yl-tosylate and 5-norbornene-2,3-dicarboximido-yl-n-butylsulfonate; But triphenylsulfonium trifluoromethanesulfonate, trifluoromethanesulfonate (p-
tert-butoxyphenyl) diphenylsulfonium, tris (p-ter
(t-butoxyphenyl) sulfonium, triphenylsulfonium p-toluenesulfonate, (p-tert-butoxyphenyl) diphenylsulfonium, p-toluenesulfonate tris (pt)
ert-butoxyphenyl) sulfonium, trifluoromethanesulfonic acid (p-tert-butoxycarbonylmethoxyphenyl) diphenylsulfonium, bis (p-dimethylaminophenyl) trifluoromethanesulfonate (p-tert-butoxyphenyl) sulfonium, p-toluenesulfone Acid tris (m-tert-butoxyphenyl) sulfonium, p-toluenesulfonic acid tris (m-tetrahydropyranyloxyphenyl)
Sulfonium, tris (p-tert-butoxyphenyl) sulfonium pentafluorobenzenesulfonate,
10-camphorsulfonic acid (p-tert-butoxyphenyl) diphenylsulfonium and the like are preferably used.

The above acid generators may be used alone or in combination of two or more.

Here, as the onium salt, the one synthesized and purified according to the following reaction formula (i) or (ii) is
When blended in a resist material, it is preferable from the viewpoint of solving the problems of storage stability deterioration such as sensitivity change and particle generation. That is, since the methods of the following reaction formulas (i) and (ii) are direct synthesis in an alkaline reaction solution, there is no mixing of acidic impurities causing the above problems, and therefore storage for 6 months or more. However, it has sufficient stability.

[0069]

Embedded image (In the formula, R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ represent an unsubstituted or substituted aromatic group. X represents a sulfonate derivative.)

The amount of the acid generator added is based on the base resin 1
1 to 20 parts, especially 2 to 10 parts is desirable with respect to 00 parts.

The chemical amplification positive type resist material of the present invention further contains (D) a dissolution control agent.

Here, as the dissolution controlling agent, (D) -1: the phenolic compound having a molecular weight of 100 to 1,000, preferably 150 to 800, and having two or more phenolic hydroxyl groups in the molecule. A compound in which hydrogen atoms of a hydroxyl group are substituted with an acid labile group at an average ratio of 10 to 100%, and (D) -2: the weight average molecular weight exceeds 1,000 and 3.0
A compound having a phenolic hydroxyl group of not more than 00 and having a hydrogen atom of the phenolic hydroxyl group in the molecule partially substituted by an acid labile group at an average of more than 0% and not more than 60% is preferably used. . in this case,
The dissolution control agent of (D) -1 alone, the dissolution control agent of (D) -2 alone, or the dissolution control agent of (D) -1 and the dissolution control agent of (D) -2 are used. And may be used in combination.

In the dissolution control agent (D) -1, the compounds having a molecular weight of 100 to 1,000 and having two or more phenolic hydroxyl groups in the molecule are represented by the following general formulas (6) to ( 16) can be illustrated.

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[0075]

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[0076]

[Chemical 21] (Wherein R ¹² and R ¹³ are each a hydrogen atom or a linear or branched alkyl group or alkenyl group having 1 to 8 carbon atoms, and R ¹⁴ is a hydrogen atom or a linear chain having 1 to 8 carbon atoms. Linear or branched alkyl group or alkenyl group, or-
(R ¹⁸⁾ is _s -COOH, R ¹⁵ is - (CH _{2) t} -
(T = 2 to 10), C6 to C10 arylene group, carbonyl group, sulfonyl group, oxygen atom or sulfur atom, R
¹⁶ is an alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, a carbonyl group, a sulfonyl group, an oxygen atom or a sulfur atom, R ¹⁷ is a hydrogen atom, a straight chain or branched chain having 1 to 8 carbon atoms An alkyl group, an alkenyl group, a phenyl group or a naphthyl group each substituted with a hydroxyl group, R ¹⁸
Is a linear or branched alkylene group having 1 to 10 carbon atoms. Further, k is an integer of 0 to 5, and s is 0 or 1. m, n, m ′, n ′, m ″ and n ″ satisfy m + n = 8, m ′ + n ′ = 5 and m ″ + n ″ = 4, respectively, and at least 1 is present in each phenyl skeleton. It is a number having one hydroxyl group. α is a number that makes the molecular weight of the compounds of the formulas (13) and (14) 100 to 1,000. )

In the above formula, R ¹² and R ¹³ are, for example, hydrogen atom, methyl group, ethyl group, butyl group, propyl group, ethynyl group, cyclohexyl group and R ¹⁴ are, for example, R
¹² , the same as R ¹³ , or —COOH, —CH ₂
COOH and R ¹⁵ are, for example, ethylene group, phenylene group, carbonyl group, sulfonyl group, oxygen atom, sulfur atom and the like, and R ¹⁶ is, for example, methylene group or R ¹⁵
Examples of R ¹⁷ similar to those described above include a hydrogen atom, a methyl group, an ethyl group, a butyl group, a propyl group, an ethynyl group, a cyclohexyl group, a phenyl group substituted with a hydroxyl group, a naphthyl group, and the like.

Here, as the acid labile group of the dissolution control agent of (D) -1, the groups represented by the above general formulas (2) and (3), a tert-butyl group, a tetrahydropyranyl group, Tetrahydrofuranyl group, trialkylsilyl group,
Examples include β-ketoalkyl groups.

In the dissolution control agent (D) -1,
The rate of substitution of the hydrogen atom of the phenolic hydroxyl group with the acid labile group is 10% or more, preferably 30% or more of the whole phenolic hydroxyl group on average, and if it is less than 10%, the edge roughness mainly occurs. The upper limit is 100%,
It is more preferably 80%.

On the other hand, in the dissolution control agent (D) -2,
The partial substitution rate of the hydrogen atom of the enolic hydroxyl group by the acid labile group exceeds 0% of the whole phenolic hydroxyl group on average and 6
It is 0% or less, preferably more than 0% and 40% or less. 0
%, A sufficient dissolution control effect cannot be obtained, and if it exceeds 60%, phase separation occurs between the polymers and the compatibility is lost.

In this case, as the compound in which the hydrogen atom of the phenolic hydroxyl group is partially substituted by such an acid labile group,
One or more compounds selected from compounds having a repeating unit represented by the following general formula (17) are preferable.

[0082]

Embedded image (However, in the formula, R represents an acid labile group, and c and d are numbers satisfying 0 ≦ c / (c + d) ≦ 0.6.)

Here, the acid labile group of the dissolution control agent of the above (D) -2 has an alkoxyalkyl group represented by the above general formula (2) and a carbonyl group represented by the above general formula (3). Group, a tert-butyl group, a tetrahydropyranyl group, a trialkylsilyl group, and a β-ketoalkyl group.

The above (D) dissolution control agent is
It can be synthesized by chemically reacting a compound having a phenolic hydroxyl group with an acid labile group as in the base resin.

The amount of the above-mentioned dissolution control agent to be added is based on the base resin 1
It is 3 to 50 parts, preferably 3 to 30 parts per 100 parts, and can be used alone or in combination of two or more.
If the blending amount is less than 3 parts, the resolution may not be improved, and if it exceeds 50 parts, the pattern film may be reduced and the resolution may be lowered.

Further, the resist material of the present invention comprises (E)
A basic compound can be added.

As the basic compound (E), a compound capable of suppressing the diffusion rate when the acid generated from the acid generator diffuses in the resist film is suitable, and such a basic compound is blended. This suppresses the acid diffusion rate in the resist film and improves resolution, suppresses sensitivity changes after exposure, reduces substrate and environment dependence, and improves exposure margin and pattern profile. It is possible to improve the sex. Such basic compounds include the first
, Secondary and tertiary aliphatic amines, hybrid amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxyl group, nitrogen-containing compounds having a sulfonyl group, nitrogen-containing compounds having a hydroxyl group , A nitrogen-containing compound having a hydroxyphenyl group, an alcoholic nitrogen-containing compound, an amide derivative and the like.

Specifically, as the primary aliphatic amine, ammonia, methylamine, ethylamine, propylamine, butylamine, pentylamine, amylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, laurylamine, Cetylamine, methylenediamine, ethylenediamine, tetraethylenediamine and the like are exemplified, and as the secondary aliphatic amine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine,
Examples thereof include dinonylamine, didecylamine, dimethylmethylenediamine, dimethylethylenediamine and dimethyltetraethylenediamine. As tertiary aliphatic amines, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, tetramethylmethylenediamine, tetramethylethylenediamine, tetramethyltetraethylenediamine, etc. Is exemplified.

Examples of the mixed amine include dimethylethylamine and methylethylpropylamine.
Specific examples of aromatic and heterocyclic amines include benzylamine, phenethylamine, benzyldimethylamine, aniline derivatives (eg, aniline, N-methylaniline,
N-ethylaniline, N-propylaniline, N, N-
Dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, ethylaniline, propylaniline, trimethylaniline, 4-nitroaniline, dinitroaniline, etc., toluidine derivatives (for example, toluidine, N, N-dimethyltoluidine). Etc.), quinoline, aminobenzoic acid, N-phenylphenyltolylamine, N-methyldiphenylamine, triphenylamine, phenylenediamine, naphthylamine, diaminonaphthalene, pyrrole derivatives (for example, pyrrole, methylpyrrole, dimethylpyrrole, N-methylpyrrole, etc.). ), An imidazole derivative (eg, imidazole, 4-
Methylimidazole, 4-methyl-2-phenylimidazole, etc.), oxazole derivative, thiazole derivative,
Pyrazole derivative, pyrrolidine derivative (eg, pyrrolidine, N-methylpyrrolidone, N-methylpyrrolidine, etc.), pyrroline derivative, pyridine derivative (eg, pyridine, methylpyridine, ethylpyridine, propylpyridine, butylpyridine, 5-butyl-2-methyl) Pyridine, trimethylpyridine, triethylpyridine, phenylpyridine, 3-methyl-2-phenylpyridine, te
rt-Butylpyridine, diphenylpyridine, benzylpyridine, methoxypyridine, butoxypyridine, dimethoxypyridine, 1-methyl-2-pyridone, 4-pyrrolidinylpyridine, 1-methyl-4-phenylpyridine, 2- (1-ethyl) Propyl) pyridine etc.), piperidine derivative, pyrimidine derivative, purine derivative, quinoline derivative, carbazole derivative, indole derivative, nicotinic acid amide derivative, adenosine derivative, adenine derivative, thiabenzol, diaminosulfone and the like.

Further, as nitrogen-containing compounds having a carboxyl group, amino acid derivatives (eg, nicotinic acid, alanine, arginine, aspartic acid, glutamic acid, glycine, histidine, isoleucine, glycylleucine,
Examples include leucine, methionine, phenylalanine, threonine, lysine, 3-aminopyrazine-2-carboxylic acid, methoxyalanine, etc., a nitrogen-containing compound having a sulfonyl group, a nitrogen-containing compound having a hydroxyl group,
As a nitrogen-containing compound having a hydroxyphenyl group and an alcoholic nitrogen-containing compound, 2-hydroxypyridine, aminocresol, thiaminenaphthalene disulfonate,
Pyridinesulfonic acid, ethanolamine, diethanolamine, triethanolamine, diisopropylamine, triisopropylamine, tripropylamine, 1
-Aminobutane-2-diol, 1-aminopropane-
Examples include 3-ol and 1-aminobutane-2-diol. Examples of the amide derivative include formamide and N-
Methylformamide, N, N-dimethylformamide,
Examples include acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide and the like.

The amount of the above basic compound to be added depends on the amount of the acid generator 1 used.
0.001-10 parts, preferably 0.01-
It is one copy. If the amount is less than 0.001 part, the effect as an additive may not be sufficiently obtained, and if it exceeds 10 parts, the resolution and sensitivity may be lowered.

In addition to the above components, the resist composition of the present invention may contain, as an optional component, a surfactant for improving the coating property, a light absorbing material for reducing the influence of irregular reflection from the substrate, and the like. . In addition, the addition amount of the optional component can be a normal amount as long as the effect of the present invention is not impaired.

In this case, examples of the surfactant include perfluoroalkyl polyoxyethylene ethanol, fluorinated alkyl ester, perfluoroalkylamine oxide, and perfluoroalkyl EO adduct, and examples of the light absorbing material include diarylsulfone. Oxide,
Diaryl sulfone, 9,10-dimethylanthracene, 9-fluorenone and the like can be mentioned.

A pattern can be formed by using the positive resist composition of the present invention by employing a known lithography technique. For example, a silicon wafer is spin-coated with 0.5 to 2.0 μm. Apply to 8
After prebaking at 0-120 ℃, deep UV, electron beam,
After exposure by irradiating high energy rays such as X-rays, 70 to 12
30-200 seconds post exposure bake (P
EB), and then development with an alkaline aqueous solution. The material of the present invention is particularly suitable for fine patterning with deep ultraviolet rays of 254 to 193 nm and electron beams among high energy rays.

[0095]

Industrial Applicability The chemically amplified positive resist composition of the present invention is sensitive to high energy rays such as deep ultraviolet rays, electron beams and X-rays, particularly KrF excimer laser, and is excellent in sensitivity, resolution and plasma etching resistance. Moreover, the heat resistance of the resist pattern is also excellent. Further, the pattern is unlikely to be overhanging, and has excellent dimensional controllability. Therefore,
The chemically amplified positive type resist material of the present invention can be a resist material having particularly small absorption at the exposure wavelength of a KrF excimer laser due to these characteristics, has high resolution, is fine, and is perpendicular to the substrate. Since it can easily form various patterns, it is suitable as a fine pattern forming material for VLSI manufacturing.

[0096]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Synthesis Examples, Examples, and Comparative Examples, but the present invention is not limited to the following Examples.

[Synthesis Example 1] 0.5 g of lauryl peroxide, 10 g of p-tert-butoxycarbonyloxystyrene, 28 g of p-1-ethoxyethoxystyrene, 62 g of p-vinylphenol and 1,000 ml of acetone were placed in a flask. After charging, the flask was purged with nitrogen, and this mixture was reacted at 90 ° C. for 5 hours to carry out a polymerization reaction. After the completion of the polymerization reaction, the obtained polymer was washed with methanol and dried, and 90 g of a powder solid was obtained. The powder solid obtained was a polymer represented by the following rational formula Poly1, and the yield was 90%. Weight average molecular weight (Mw) and molecular weight distribution (Mw) of this polymer
/ Mn) is as shown in Table 1. When analyzed by ¹ H-NMR, a peak of methylene derived from an alkoxyalkyl group was observed at 5.3 ppm, and a peak derived from a t-BOC group was observed at 1.5 ppm. .. Further, as a result of calculation from the ¹ H-NMR integration ratio, p-1-ethoxyethoxystyrene unit (p), p-tert-butoxycarbonyloxystyrene unit (q), p-vinylphenol unit (r)
The composition ratio of was as shown in Table 1.

[Synthesis Examples 2 and 3] In Synthesis Example 1, p-
Poly2 was prepared in the same manner as in Synthesis Example 1 except that p-1-methoxyethoxystyrene (Synthesis Example 2) and p-1-n-butoxyethoxystyrene (Synthesis Example 3) were used instead of 1-ethoxyethoxystyrene. Got 3.

The structure of the obtained polymer is shown by the following rational formula Po.
ly2 and 3 as described above, and the respective weight average molecular weights,
The molecular weight distribution was as shown in Table 1.

[Synthesis Example 4] Monodisperse poly (p-1-ethoxyethoxystyrene-p)
-Tert-butoxycarbonyloxystyrene-p-
(Hydroxystyrene) was synthesized in a 2 L flask using 700 ml of tetrahydrofuran as a solvent and 7 × sec-butyllithium as an initiator.
10 ⁻³ mol was charged. P-at this mixed solution at -78 ° C
100 g of -tert-butoxystyrene was added and polymerized while stirring for 1 hour. The reaction solution turned red. The polymerization was completed by adding methanol to the reaction solution.

Then the reaction mixture is poured into methanol,
The polymer obtained was precipitated, separated, and dried to obtain 99 g of a white polymer (poly p-tert-butoxystyrene). The number average molecular weight was 1.4 × 10 ⁴ g / mol as measured by the membrane osmometry. GPC
Very monodisperse (Mw /
It was confirmed that the polymer was high in Mn = 1.07).

Next, 90 g of the above poly-p-tert-butoxystyrene was dissolved in 900 ml of acetone, a small amount of concentrated sulfuric acid was added at 60 ° C., the mixture was stirred for 7 hours, poured into water to precipitate the polymer, washed and dried. , 60 g of polymer were obtained. The number average molecular weight of the obtained polymer is 1.0.
× 10 ⁴ g / mol. In addition, ¹ H-NMR
Since no peak derived from t-butyl group was observed, it was confirmed that the obtained polymer was poly (hydroxystyrene) having a narrow molecular weight distribution.

100 g of the obtained polyhydroxystyrene
Was dissolved in 1000 ml of dimethylformamide, a catalytic amount of pyridinium p-toluenesulfonate was added, and then 30 g of ethyl vinyl ether was added while stirring at 30 ° C.
Was added. After reacting for 16 hours, the mixture was neutralized with concentrated aqueous ammonia, and the neutralization reaction solution was added dropwise to 10 L of water to obtain a white solid. After filtering this, acetone 50
It was dissolved in 0 ml, added dropwise to 10 L of water, filtered, and vacuum dried. It was confirmed from ¹ H-NMR that the hydrogen atom of the hydroxyl group of polyhydroxystyrene was 27% ethoxyethylated in the obtained polymer.

Further, 50 g of the partially ethoxyethylated polyhydroxystyrene obtained was dissolved in 500 ml of pyridine, and 7 g of di-tert-butyl dicarbonate was added while stirring at 45 ° C. After reacting for 1 hour, the reaction solution was added dropwise to 3 L of water to obtain a white solid. After filtration, this was dissolved in 50 ml of acetone, dropped into 2 L of water, filtered, and dried under vacuum to obtain a polymer. The obtained polymer has a structure represented by the following rational formula Poly4, ¹ H
From NMR, the ethoxyethylation rate of hydrogen atoms of hydroxyl groups of polyhydroxystyrene is 27%, the t-BOC conversion rate of hydrogen atoms of hydroxyl groups is 8% (Poly4), and the weight average molecular weight (Mw) and molecular weight distribution (Mw). / Mn) is as shown in Table 1, and the GPC elution curve is as shown in FIG.

Synthesis Example 5 Monodisperse poly (p-1-ethoxypropoxystyrene)
p-tert-butoxycarbonyloxystyrene-p
-Hydroxystyrene) 50 g of polyhydroxystyrene obtained in the same manner as in Synthesis Example 4 above was dissolved in 500 ml of dimethylformamide, and a catalytic amount of p-toluenesulfonic acid pyridinium salt was added to the solution, followed by stirring at 40 ° C. 27 g of ethoxypropenyl was added. After reacting for 12 hours, the mixture was neutralized with concentrated aqueous ammonia, and the neutralization reaction liquid was added dropwise to 10 L of water to obtain a white solid. This was filtered, dissolved in 500 ml of acetone, added dropwise to 10 L of water, filtered, and vacuum dried. It was confirmed from ¹ H-NMR of the obtained polymer that the hydrogen atoms of the hydroxyl groups of polyhydroxystyrene were 24% ethoxypropylated.

Further, 50 g of the partially ethoxypropoxylated polyhydroxystyrene thus obtained was dissolved in 500 ml of pyridine, and di-tert-dicarbonate was stirred at 45 ° C.
8 g of butyl were added. After reacting for 1 hour, the reaction solution was added dropwise to 3 L of water to obtain a white solid. After filtration, this was dissolved in 50 ml of acetone, dropped into 2 L of water, filtered, and dried under vacuum to obtain a polymer. The obtained polymer has a structure represented by the following rational formula: ¹ H—N
From MR, the ethoxypropylation rate of hydrogen atoms of the hydroxyl group of polyhydroxystyrene is 24%, the t-BOC conversion rate is 11
% (Poly5), and the weight average molecular weight (Mw) and the molecular weight distribution (Mw / Mn) were as shown in Table 1.

[Synthesis Examples 6 to 16] Polymers (Poly6 to 16) represented by the following rational formulas Poly6 to 16 were obtained by the same method as in Synthesis Examples 4 and 5.

The structure of the obtained polymer was as shown in the following rational formula, and the weight average molecular weight and molecular weight distribution of each were as shown in Table 1.

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[0110]

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[0112]

[Table 1]

[Examples 1 to 34, Comparative Examples 1 to 4] Polymers 1 (Poly1) to 14 (Poly14) obtained in the above synthesis examples were used as base resins, and the following formulas (PAG1) to (PAG8) were used. In the compositions shown in Tables 2 to 4, the acid generator represented by the formula (1), the dissolution control agent represented by the following formulas (DRR1) to (DRR14), and the basic compound are used: diethylene glycol dimethyl ether (DGLM), ethyl lactate (EL) / butyl acetate. (BA), propylene glycol monomethyl acetate (PGMMA), propylene glycol monoethyl acetate (PGMEA)
To prepare a resist material, and further add each composition to 0.
By filtering with a 2 μm Teflon filter,
Each resist solution was prepared.

For comparison, as shown in Table 4, a resist solution was prepared in the same manner as above using the polymers represented by the above formulas (Poly15) and (Poly16) as the base resin.

The resist solution thus obtained was spin-coated on a silicon wafer and applied to a thickness of 0.8 μm. Then, this silicon wafer was baked at 100 ° C. for 120 seconds using a hot plate. This is an excimer laser stepper (Nikon, NSR-2005E
X8A, NA = 0.5) and exposed at 90 ° C. for 60
A second pattern was obtained by second baking and development with an aqueous solution of 2.38% tetramethylammonium hydroxide. The obtained resist pattern was evaluated as follows. The results are shown in Tables 2 to 4. Evaluation method: First, the sensitivity (Eth) was determined. Then 0.3
The exposure amount for resolving a 5 μm line and space at a ratio of 1: 1 was taken as the optimum exposure amount (Eop), and the minimum line width of the separated line and space in this exposure amount was taken as the resolution of the evaluation resist. The shape of the resolved resist pattern was observed using a scanning electron microscope.

In addition, the unevenness (edge roughness) of 0.25 μm line and space was measured by a scanning electron microscope.

From the results of Tables 2 to 4, it was confirmed that the chemically amplified positive resist composition of the present invention gave a pattern having high resolution and no unevenness (small edge roughness).

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[0119]

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[0121]

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[0123]

[Table 2]

[0124]

[Table 3]

[0125]

[Table 4]

[Examples 35 to 69] Polymer 1 (Poly1) obtained in the above-mentioned synthesis example to polymer 14 (Poly)
y14) is used as a base resin, and the above formula (PAG
1) to (PAG8), a compound having a phenolic hydroxyl group, and an acid labile group obtained by chemically reacting an acid labile group with a compound having a phenolic hydroxyl group, represented by the following formula (DR
R1 ′) to (DRR8 ′) and the above-mentioned formulas (DRR1) to (DRR14), the dissolution controlling agent, and the basic compound in the compositions shown in Tables 5 and 6 are diethylene glycol dimethyl ether (DGLM) and ethyl lactate (EL). / Butyl acetate (BA), Propylene glycol monomethyl acetate (PGMMA), Propylene glycol monoethyl acetate (PGMEA) dissolved in to prepare a resist material, and by filtering each material with a 0.2 μm Teflon filter, Each resist solution was prepared.

The resist solution thus obtained was evaluated in the same manner as in the above example. The results are shown in Tables 5 and 6.

From the results shown in Tables 5 and 6, the chemically amplified positive resist composition of the present invention has good sensitivity and high resolution.
It was confirmed that it is possible to obtain a pattern having no unevenness (small edge roughness).

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[0131]

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[0132]

[Table 5]

[0133]

[Table 6]

[Brief description of drawings]

FIG. 1 is a graph showing a GPC elution curve of a polymer compound obtained in Synthesis Example 4.

Continuation of the front page (31) Priority claim number Japanese Patent Application No. 7-337901 (32) Priority Day Hei 7 (1995) December 1 (33) Priority claiming country Japan (JP) (72) Inventor Toshinobu Ishihara Niigata 28-1 Nishi-Fukushima, Kubiki-mura, Nakakubiki-gun, Fukushima Shin-Etsu Chemical Co., Ltd.

Claims (12)

[Claims] 1. An organic solvent (A) having a repeating unit represented by the following general formula (1) as a base resin (B) and having a weight average molecular weight of 3,000 to 30.
A high molecular weight compound of 10,000 (However, in the formula, R ¹ is a hydrogen atom or a methyl group, and R ² ,
R ³ is an acid labile group different from each other. p, q, and r are positive numbers, and 0.02 ≦ p / (p + q + r) ≦ 0.5, 0.0
1 ≦ q / (p + q + r) ≦ 0.3, 0 <(p + q) /
It is a number that satisfies (p + q + r) ≦ 0.8. a is 1
It is a positive number of 3. (C) A chemically amplified positive resist material containing an acid generator. 2. The chemically amplified positive resist composition according to claim 1, further comprising (D) a dissolution control agent. 3. The dissolution control agent of component (D) has a molecular weight of 1
The average number of hydrogen atoms of the phenolic hydroxyl group of the compound having a number of 0 to 1,000 and two or more phenolic hydroxyl groups in the molecule is 10 to 100% as a whole due to the acid labile group.
The chemically amplified positive type resist material according to claim 2, which is a compound substituted at a ratio of. 4. The dissolution control agent of the component (D) has a weight average molecular weight of more than 1,000 and not more than 3,000, and the hydrogen atom of the phenolic hydroxyl group of the compound having a phenolic hydroxyl group in the molecule is acid. Average of 0 due to unstable groups
3. The chemically amplified positive resist composition according to claim 2, which is a compound partially substituted at a ratio of more than 60% and not more than 60%. 5. A compound having a molecular weight of 100 to 1,000 and having two or more phenolic hydroxyl groups in the molecule as a dissolution control agent of the component (D), wherein the hydrogen atom of the phenolic hydroxyl group is an acid labile group. As a whole, an average of 10 to 10
A compound substituted at a ratio of 0% and a weight average molecular weight of 1,
000 or more and 3,000 or less, and the hydrogen atom of the phenolic hydroxyl group of the compound having a phenolic hydroxyl group in the molecule is more than 0% on average as a whole due to the acid labile group and 6
The chemically amplified positive resist composition according to claim 2, which is used together with a compound partially substituted at a ratio of 0% or less. 6. A compound having a molecular weight of 100 to 1,000 and having two or more phenolic hydroxyl groups in the molecule,
The chemically amplified positive resist composition according to claim 3 or 5, which is one or more selected from compounds represented by the following general formulas (6) to (16). Embedded image Embedded image Embedded image (Wherein R ¹² and R ¹³ are each a hydrogen atom or a linear or branched alkyl group or alkenyl group having 1 to 8 carbon atoms, and R ¹⁴ is a hydrogen atom or a linear chain having 1 to 8 carbon atoms. Linear or branched alkyl group or alkenyl group, or-
(R ¹⁸⁾ is _s -COOH, R ¹⁵ is - (CH _{2) t} -
(T = 2 to 10), C6 to C10 arylene group, carbonyl group, sulfonyl group, oxygen atom or sulfur atom, R
¹⁶ is an alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, a carbonyl group, a sulfonyl group, an oxygen atom or a sulfur atom, R ¹⁷ is a hydrogen atom, a straight chain or branched chain having 1 to 8 carbon atoms An alkyl group, an alkenyl group, a phenyl group or a naphthyl group each substituted with a hydroxyl group, R ¹⁸
Is a linear or branched alkylene group having 1 to 10 carbon atoms. Further, k is an integer of 0 to 5, and s is 0 or 1. m, n, m ′, n ′, m ″ and n ″ satisfy m + n = 8, m ′ + n ′ = 5 and m ″ + n ″ = 4, respectively, and at least 1 is present in each phenyl skeleton. It is a number having one hydroxyl group. α is a number that makes the molecular weight of the compounds of the formulas (13) and (14) 100 to 1,000. ) 7. The weight average molecular weight exceeds 1,000 3,
The chemical amplification according to claim 4 or 5, wherein the compound having a phenolic hydroxyl group in the molecule of 000 or less is one or more selected from compounds having a repeating unit represented by the following general formula (17). Positive resist material. Embedded image (However, in the formula, R represents an acid labile group, and c and d are numbers satisfying 0 ≦ c / (c + d) ≦ 0.6.) 8. In the general formula (1), R ² is a group represented by the following general formula (2), and R ³ is a group represented by the following general formula (3), a tetrahydropyranyl group, and tetrahydrofuranyl. The chemically amplified positive resist composition according to claim 1, which is a group or a trialkylsilyl group. [Chemical 6] (However, in the formula, R ⁴ and R ⁵ are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms,
R ⁶ is a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms. R ⁷ is a linear or branched alkyl group having 1 to 6 carbon atoms, and b is 0 or 1. ) 9. R ² is an alkoxyalkyl group and R ³ is t.
The chemically amplified positive resist composition according to claim 8, which is an ert-butoxycarbonyl group. 10. The chemically amplified positive resist composition according to claim 1, further comprising a basic compound as an additive (F). 11. The chemically amplified positive resist composition according to claim 1, wherein the base resin is a monodisperse polymer having a molecular weight distribution of 1.0 to 1.5. 12. The chemically amplified positive resist composition according to claim 1, wherein the acid generator as the component (C) is an onium salt.