JP3239772B2 - Chemically amplified positive resist material - Google Patents

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,
As the integration and speed of LSIs increase, the pattern rule is required to be finer. With the light exposure currently used as a general-purpose technology, the essential resolution limit derived from the wavelength of the light source is approaching. It is getting. In light exposure using a g-line (436 nm) or an i-line (365 nm) as a light source, a pattern rule of about 0.5 μm is limited, 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. Deep-UV lithography can process 0.3 μm or less, and when a resist material having low light absorption is used, a pattern having sidewalls almost perpendicular to the substrate can be formed.

A recently developed acid-catalyzed chemically amplified positive resist material (Japanese Patent Publication No. 2-27660,
U.S. Pat. No. 3,278,829) uses a high-intensity KrF excimer laser as a light source of far ultraviolet light, and is particularly promising for far ultraviolet lithography having high sensitivity, high resolution, high dry etching resistance, and excellent characteristics. It is expected as a resist material.

[0005] Such chemically amplified positive resist materials include 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. Component systems are known.

For example, Japanese Patent Application Laid-Open No. 62-115440 discloses a resist material comprising poly-p-tert-butoxystyrene and an acid generator. T in the molecule
A two-component resist material comprising a resin having an tert-butoxy group and an acid generator. Further, Japanese Patent Application Laid-Open No. Hei 4-21258 discloses a polymethacrylate containing a methyl group, an isopropyl group, a tert-butyl group, a tetrahydropyranyl group and a trimethylsilyl group. A two-component resist material comprising 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], 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 a tert-butyl group or a tert-butoxycarbonyl group. In this case, the pattern shape of the resist material is likely to be a T-top shape, while an alkoxyalkyl group such as an ethoxyethyl group is decomposed by a weak acid, so that with the lapse of time from exposure to heat treatment. All have problems, such as the disadvantage that the pattern shape is extremely thin, and the sensitivity and resolution are not satisfactory.Currently, it has not yet 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 higher sensitivity, higher resolution, exposure latitude, and process adaptability than conventional resist materials when blended in a resist material as a base resin.

[0010]

Means for Solving the Problems and Embodiments of the Invention The present inventors have made intensive studies in order to achieve the above object, and as a result, have found that a repeating unit represented by the following general formula (1) obtained by a method described below is used. Having a weight average molecular weight of 3,000 to
A polymer compound which is a monodisperse polymer having a molecular weight distribution of 1.0 to 1.5 and a molecular weight of 300,000 is effective as a base resin for a chemically amplified positive resist material. This polymer compound, an acid generator and an organic solvent And having a carboxyl group
A nitrogen compound, a nitrogen-containing compound having a hydroxyl group, and
Selected from nitrogen-containing compounds having a hydroxyphenyl group
The resist composition comprising a that a basic compound,
More preferably, the chemically amplified positive resist material further containing a dissolution controlling agent enhances the dissolution contrast of the resist film, and particularly increases the dissolution rate after exposure, and provides high resolution, exposure latitude, and process adaptability. It has been found that it is advantageous in precision and fine processing with high practicability and high practicality, and is very effective as a resist material for VLSI.

[0011]

Embedded image (Wherein ^{R 1} is a hydrogen atom or a methyl group, ^{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, a tetrahydrofuranyl group or a trialkylsilyl group.
p, q, and r are positive numbers and 0.02 ≦ p / (p + q + r) ≦
0.5, 0.01 ≦ q / (p + q + r) ≦ 0.3, 0 <
This is a number that satisfies (p + q) / (p + q + r) ≦ 0.8. a is a positive number from 1 to 3. )

Here, the high molecular compound represented by the general formula (1) is a compound in which a part of the phenolic hydroxyl group is protected by two kinds of acid labile groups. When such a polymer compound is blended in a resist material as a base resin, particularly,
R ² is represented by the following general formula (2)
An alkoxyalkyl group such as an ethoxyethyl group, an ethoxypropyl group, a butoxyethyl group, or the like;
^{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, the resist is The materials have the advantages of a resist material possessed by each acid labile group, such as alkali dissolution inhibition by an acid labile group such as a carbonyl group of R ³ , and ease of desorption by an alkoxyalkyl group of R ^2. The disadvantages that occur when a stable group is introduced alone can be derived while complementing each other.

[0013]

Embedded image (Wherein 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, the elimination reaction proceeds with a weak acid, so that it is difficult to form a T-top shape. Due to the sensitivity, the pattern shape becomes extremely thin with the passage of time from exposure to heat treatment, and the effect of inhibiting dissolution against alkali is low. However, it has the disadvantage of lacking heat resistance.

On the other hand, when the phenolic hydroxyl group of the above polymer compound is protected with, for example, only a t-BOC group, and it is blended with a resist material, the alkali dissolution inhibiting property is good, and a dissolution contrast can be obtained with a low substitution rate. Although it has the advantage of good heat resistance, it is necessary to make a strong acid such as trifluoromethanesulfonic acid exist in order to be eliminated and made alkali soluble, and as described above when such an acid is used. 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 for the resist material. Without compromising each other's strengths.

Further, when a dissolution controlling agent is added, the dissolution contrast of the resist film is enhanced, and the dissolution rate particularly after exposure is increased. That is, when the above dissolution controlling agent is added,
It is well compatible with the base resin of general formula (1) and the acid generator, increases the dispersibility of the acid generator, increases the density of the matrix, and controls the movement of the acid generated after exposure by uniformity to control the solution. Improves image quality and rectangularity. In the patterning process of exposure, heating, and development, the dissolution rate of the alkali-soluble resin as the matrix is suppressed in the unexposed area, and the acid labile groups of the alkali-soluble resin as the matrix are decomposed in the exposed area. From this fact, the dissolution rate in the alkaline aqueous solution is promoted, the penetration of the alkaline aqueous solution into the membrane is increased, and the dissolution controlling agent is rapidly dissolved, so that the alkali-soluble resin that has not been sufficiently dissolved is blocked. Due to the release into the aqueous alkali solution, the apparent alkali dissolution increases rapidly.

From these facts, a chemically amplified positive resist material using the polymer compound represented by the general formula (1) as a base resin is likely to have a T-top shape, a thin pattern shape, and lack heat resistance. The problem is much less than the conventional one, resulting in high sensitivity and high resolution,
In addition, it is possible to arbitrarily control the dimension of the pattern and the shape of the pattern by the composition, and it has been found that the resist is a chemically amplified positive resist material having excellent process adaptability, and has led to the present invention. It is.

Accordingly, the present invention provides (I) (A) an organic solvent, (B) a base resin having a repeating unit represented by the following general formula (1), and a weight average molecular weight of 3,000 to 30:
A polymer compound which is a monodisperse polymer having a molecular weight distribution of 1.0 to 1.5 at 000 (C) an acid generator; (E) a nitrogen-containing compound having a carboxyl group;
Nitrogen-containing compound having sil group and hydroxyphenyl group
A chemically amplified positive resist material comprising a basic compound selected from nitrogen-containing compounds having: (II) and (D) further comprising (D) a dissolution controlling agent
The present invention provides a chemically amplified positive resist material as described above.

[0020]

Embedded image (Wherein ^{R 1} is a hydrogen atom or a methyl group, ^{R 2}
Is a group represented by the general formula (2), and R ³ is a group represented by the general formula (3), a tetrahydropyranyl group, a tetrahydrofuranyl group or a trialkylsilyl group.
p, q, and r are positive numbers and 0.02 ≦ p / (p + q + r) ≦
0.5, 0.01 ≦ q / (p + q + r) ≦ 0.3, 0 <
This is a number that satisfies (p + q) / (p + q + r) ≦ 0.8. a is a positive number from 1 to 3. )

Now, the present invention will be described in further detail. The chemically amplified positive resist composition of the present invention comprises (A) an organic solvent, (B) a base resin, (C) an acid generator, and (E) a salt.
Shall be the main component based compound is also of a.

Here, (A) the organic solvent includes (B)
Any organic solvent may be used as long as it can dissolve the acid generator, the base resin, the dissolution controlling agent, and the like of the component (D). Such organic solvents include, for example, cyclohexanone, methyl-
Ketones such as 2-n-amyl ketone, alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, propylene glycol monomethyl ether, ethylene Glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, ethers such as diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, Esters such as methyl-3-methoxypropionate and ethyl-3-ethoxypropionate are exemplified. 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 (parts by weight, hereinafter the same) of the base resin.
Particularly, 400 to 800 parts is suitable. If the amount is less than 200 parts, the compatibility may be reduced and the film formability may be deteriorated.
When the amount exceeds 00 parts, the resist film is formed into a thin film when formed, and may not be usable.

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. ^Further, R 2, ^{R 3} is an acid labile group, ^{R 2} is a group represented by the following general formula (2), ^{R 3}
Is a group represented by the following general formula (3), a tetrahydropyranyl group, a tetrahydrofuranyl group or a trialkylsilyl group.

[0027]

Embedded image (Wherein 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 and a tert-butyl group. Examples of the alkyl group include a cyclohexyl group and the like.

Here, specific examples of the acid labile group represented by the above formula (2) include, for example, methoxyethyl group, ethoxyethyl group, n-propoxyethyl group, iso-propoxyethyl group, n-butoxy group. Ethyl group, iso-butoxyethyl group, tert-butoxyethyl group, cyclohexyloxyethyl group, methoxypropyl group, ethoxypropyl group, 1-methoxy-1-methyl-ethyl group, 1-
An ethoxy-1-methyl-ethyl group and the like are exemplified, 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 a trimethylsilyl group and a tri-tert-butyldimethylsilyl group. Among these, considering the properties of a resist material containing the polymer compound of the present invention as a base resin, the polymer compound represented by the above formula (1) is preferably 2
Examples of the acid labile group include an alkoxyalkyl group represented by the above formula (2) as R ² and tert- as R ^3.
It is desirable to combine 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. If any of p, q, and r becomes 0 and the polymer compound of the above formula (1) does not contain any unit, the contrast of the alkali dissolution rate decreases, and the resolution deteriorates. If the ratio of p to the whole (p + q + r, the same applies hereinafter) is less than 0.02 and the ratio of q to the whole is less than 0.01, the advantages of each acid labile group cannot be derived, and the ratio of p to the whole Exceeds 0.5, and p and q
When the total ratio of the polymer and the total exceeds 0.8, the glass transition temperature of the polymer compound decreases, heat resistance deteriorates, or a change in film thickness, film stress or generation of bubbles during alkali development or In addition, since the number of hydrophilic groups is reduced, the adhesion to the substrate may be poor. Further, by appropriately selecting the values of p, q, and r within the above range, the dimension control of the pattern and the shape control of the pattern can be arbitrarily performed. Note that a in the above formula (1) is a positive number of 1 to 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 affects the characteristics of the resist material such as pattern dimension control and pattern shape.

Each of the base resins of the present invention has a weight average molecular weight (the measuring method is as described later) 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 becomes inferior in heat resistance.
If it exceeds 000, the alkali solubility is reduced, and the tailing phenomenon tends to occur after pattern formation.

Further, in the base resin of the present invention, when the molecular weight distribution (Mw / Mn) is wide, a low molecular weight or high molecular weight polymer is present, and when a large amount of low molecular weight polymer is present, heat resistance may be reduced. In some cases, when a large amount of high molecular weight polymer is present, some of them are difficult to dissolve in alkali, and may cause tailing after pattern formation. Therefore, as the pattern rule becomes finer, the influence of such molecular weight and molecular weight distribution tends to increase. Therefore, in order to obtain a resist material suitably used for fine pattern dimensions, the molecular weight distribution of the base resin must be as follows. 0 to
Monodispersion of 1.5, especially 1.0 to 1.3 is preferred.

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

[0035]

Embedded image (Wherein, R ¹ , R ² , R ³ and a have the same meaning as described above)

Further, particularly when applied to a resist material having a fine pattern rule, a monodisperse polymer compound is desirable for the above-mentioned reasons. A polymer having a wide molecular weight distribution obtained by polymerization is separated to have a molecular weight distribution of 1.
Monodispersion is obtained by obtaining a material of 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, a commonly used one can be used in a usual amount, but an organic peroxide, especially an organic peroxide having a 10-hour half-life of 40 ° C. to 90 ° C. (eg, lauroyl) Peroxide) is more preferably used.

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

Further, the polymer compound of the present invention is obtained by subjecting a monomer represented by the following structural formula (4) to radical polymerization or addition polymerization (living anionic polymerization), and then hydrolyzing the resulting monomer to form a hydroxyl group generated by the hydrolysis. It can be partially prepared, for example, by protecting the first acid labile group of the above formula (2) and the second acid labile group of the above formula (3) by a chemical reaction.

[0041]

Embedded image (Wherein, R ¹ has the same meaning as described above.)

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

On the other hand, when the base resin of the present invention is produced by living anion polymerization using the monomer of the above formula (4), it can be carried out using a known living anion polymerization initiator. In order to obtain the above polymer compound, it is preferable to use an organometallic compound among living anionic 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 the living anionic polymerization initiator added is determined by the design molecular weight (= monomer weight / mol number of initiator).
Is calculated from the relationship

The living anionic polymerization of the above monomers is
Generally, it is performed 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 suitably from 1 to 30% by weight, and the reaction is desirably carried out under high vacuum or with stirring under an inert gas atmosphere such as argon or nitrogen. The reaction temperature can be arbitrarily selected from -78 ° C to the boiling point of the reaction solution to be used. In particular, it is preferably -78 ° C to 0 ° C for a tetrahydrofuran solvent, and room temperature when a benzene solvent is used.

The polymerization reaction can be performed 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 termination of the polymerization reaction can be carried out by adding a terminator such as methanol, water, methyl bromide or the like to the reaction system.

[0048]

Embedded image (Wherein, R ¹ has the same meaning as described above.)

In the living anionic polymerization reaction, since the monomer reacts 100% and the molecular weight can be appropriately adjusted, 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 a 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 group generated by the hydrolysis is successively protected by the acid labile groups represented by R ² and R ³ , whereby the desired monodispersion (that is, the molecular weight distribution is 1.
0 to 1.5), and the weight average molecular weight (that is, 3,
000-300,000) can be obtained.

[0052]

Embedded image (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 a tert-butyl group, which is a protecting group for the hydroxyl group, is hydrolyzed, hydrochloric acid, odor 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 an acid such as hydrofluoric acid. According to such a method, since the main chain of the polymer compound is not cut during the reaction and a cross-linking reaction does not occur between the molecules, 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 as follows:
After removing the hydroxyl-protecting group by hydrolysis as described above, the reaction can be carried out by introducing acid labile groups R ² and R ³ 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 form a hydroxyl group of polyhydroxystyrene as shown by the following formula. (A ratio of p mol to 1 mol of all hydroxyl groups) is protected by an alkoxyalkyl group.

[0056]

Embedded image (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 and propenyl ether. This reaction is preferably performed in the presence of a solvent such as dimethylformamide, tetrahydrofuran, or dimethylacetamide. As the acid, hydrochloric acid, sulfuric acid, p-
Toluenesulfonic acid, methanesulfonic acid, pyridinium p-toluenesulfonate, and the like are used, and the amount thereof is preferably 0.1 to 10 mol% based on 1 mol of all hydroxyl groups of polyhydroxystyrene to be reacted. The reaction temperature is preferably from room temperature to 60 ° C, and the reaction time is usually from 1 to 20 ° C.
Time.

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

After the alkoxyalkylation reaction is performed, a tert-butoxycarbonylation reaction, a tert-butoxycarbonylmethylation reaction, etc. are performed to introduce the acid labile group R ³ .

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

The tert-butoxycarbonylmethylation reaction is carried out by adding potassium-tert-butoxide and tert-butoxide to the above partially alkoxyalkylated polyhydroxystyrene in a solvent such as dimethyl sulfoxide or tetrahydrofuran.
The reaction can be carried out by reacting tert-butoxycarbonylmethyl bromide. In this case, the amount of potassium tert-butoxide used is tert-butanol per 1 mol of all hydroxyl groups of the polyhydroxystyrene of the above formula.
This is the amount in which the butoxycarbonylmethyl group is introduced in q moles. The amount of tert-butoxycarbonylmethyl bromide used is equimolar to that of 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 performed by reaction with a trialkylsilyl chloride in the presence of imidazole. In these cases, the reaction temperature is preferably from room temperature to 50 ° C, and the reaction time is usually from 1 to 5 hours.

Of these methods, in particular, in this method, tert
A -butoxycarbonyl group or a tert-butoxycarbonylmethyl group is preferably introduced, 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 described above.)

The (C) acid generator of the chemically amplified positive resist composition of the present invention includes, for example, onium salts, sulfonic acid ester derivatives, diazosulfonic acid derivatives and the like. Glass transition temperature (Tg) tends to lower because of having a group such as alkoxyalkyl. In order to prevent this, onium salts having high acid generation efficiency and high dissolution inhibiting effect are particularly preferable.

Examples of the acid generator (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, trifluoromethanesulfonate Dicyclohexylphenylsulfonium, p-toluenesulfonic acid dicyclohexylphenylsulfonium, trifluoromethanesulfonic acid (pt
tert-butoxycarbonylmethoxyphenyl) diphenylsulfonium, tris (p-tert-butoxycarbonylmethoxyphenyl) sulfonium trifluoromethanesulfonate, bis (p-dimethylaminophenyl) (p-tert-butoxyphenyl) sulfonium trifluoromethanesulfonate, trifluoro Bis (p-tert-butoxyphenyl) methanemethanesulfonate (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, diphenylsulfonium (m-tetrahydropyranyloxyphenyl) p-toluenesulfonate, bis (m-tetrahydropyranyloxyphenyl) phenylsulfonium p-toluenesulfonate Tris (m-tetrahydropyranyloxyphenyl) sulfonium p-toluenesulfonate, diphenylsulfonium p-toluenesulfonate (p-tetrahydropyranyloxyphenyl), bis (p-tetrahydropyranyloxyphenyl) p-toluenesulfonate 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,
Tris pentafluorobenzenesulfonic acid (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
onium salts such as (t-butoxyphenyl) sulfonium,
Β-ketosulfone derivatives such as 2-cyclohexylcarbonyl-2- (p-toluenesulfonyl) propane, 2-iso-propylcarbonyl-2- (p-toluenesulfonyl) propane, bis (benzenesulfonyl) diazomethane, bis (cyclohexylsulfonyl) Diazomethane derivatives such as diazomethane and bis (tert-butylsulfonyl) diazomethane; disulfone derivatives such as diphenyldisulfone and dicyclohexyldisulfone; 2,6-dinitrobenzyl p-toluenesulfonate; 2,4-dinitrobenzyl p-toluenesulfonate; Nitrobenzylsulfonate derivatives, 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)
tert-butoxyphenyl) sulfonium, trifluoromethanesulfonic acid (p-tert-butoxycarbonylmethoxyphenyl) diphenylsulfonium, bis (p-dimethylaminophenyl) trifluoromethanesulfonate (p-tert-butoxyphenyl) sulfonium, p-toluenesulfone Tris (m-tert-butoxyphenyl) sulfonium acid, tris (m-tetrahydropyranyloxyphenyl) p-toluenesulfonate
Sulfonium, tris (p-tert-butoxyphenyl) sulfonium pentafluorobenzenesulfonate,
10-Camphorsulfonic acid (p-tert-butoxyphenyl) diphenylsulfonium and the like are preferably used.

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

The onium salt synthesized and purified according to the following reaction formula (i) or (ii):
It is preferable to use the compound in a resist material in order to solve the problems of storage stability deterioration such as change in sensitivity and generation of particles. That is, since the methods of the following reaction formulas (i) and (ii) are directly synthesized in an alkaline reaction solution, they do not contain acidic impurities which cause the above-mentioned problems, and are therefore stored 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 depends on the amount of the base resin 1
1 to 20 parts, particularly 2 to 10 parts, is desirable for 00 parts.

The chemically amplified positive resist composition of the present invention further contains (D) a dissolution controlling agent.

Here, as the dissolution controlling agent, (D) -1: a phenolic compound of a 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. (D) -2: a compound in which a hydrogen atom of a hydroxyl group is substituted by an acid labile group at an average rate of 10 to 100%, and (D) -2: a weight average molecular weight of more than 1,000 to 3.0
A compound having a phenolic hydroxyl group of not more than 00 and having a hydrogen atom of the phenolic hydroxyl group partially substituted with an acid labile group at an average rate of more than 0% and not more than 60% as a whole is preferably used. . in this case,
Using only the dissolution controlling agent of (D) -1 or using only the dissolution controlling agent of (D) -2, or the dissolution controlling agent of (D) -1 and the dissolution controlling agent of (D) -2 May be used in combination.

Here, in the dissolution controlling agent of (D) -1, as a compound having a molecular weight of 100 to 1,000 and having two or more phenolic hydroxyl groups in the molecule, the following general formulas (6) to ( 16) can be exemplified.

[0074]

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[0075]

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[0076]

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. Or branched alkyl or alkenyl group, or-
(R ¹⁸ ) _s —COOH, and R ¹⁵ is — (CH ₂ ) _t —
(T = 2 to 10), an arylene group having 6 to 10 carbon atoms, a carbonyl group, a sulfonyl group, an oxygen atom or a 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 linear or branched chain having 1 to 8 carbon atoms. alkyl group, an alkenyl group, a phenyl group or a naphthyl group substituted with each hydroxyl, R ¹⁸
Is a linear or branched alkylene group having 1 to 10 carbon atoms. K is an integer of 0 to 5, and s is 0 or 1. m, n, m ′, n ′, m ″, and n ″ each satisfy m + n = 8, m ′ + n ′ = 5, m ″ + n ″ = 4, and at least 1 It is a number having two hydroxyl groups. α is a number such that the molecular weight of the compounds of the formulas (13) and (14) is 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 include, for example, an ethylene group, a phenylene group, a carbonyl group, a sulfonyl group, an oxygen atom and a sulfur atom, and R ¹⁶ includes, for example, a methylene group or R ¹⁵
Examples of R ¹⁷ 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, the acid labile group of the dissolution controlling agent of (D) -1 includes groups represented by the above general formulas (2) and (3), tert-butyl group, tetrahydropyranyl group, Tetrahydrofuranyl group, trialkylsilyl group,
β-ketoalkyl groups and the like.

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

[0080] On the other hand, 6 exceeds the full <br/> partial substitution ratio by acid labile groups of the hydrogen atoms of the phenol hydroxyl group, 0% of the total phenolic hydroxyl groups in average in the dissolution control agent (D) -2
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, the compound in which the hydrogen atom of the phenolic hydroxyl group is partially substituted with such an acid labile group includes:
One or more compounds selected from compounds having a repeating unit represented by the following general formula (17) are preferred.

[0082]

Embedded image (Wherein, R represents an acid labile group, and c and d are numbers satisfying 0 ≦ c / (c + d) ≦ 0.6, respectively)

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

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

The compounding amount of the above-mentioned dissolution controlling agent is based on base resin 1
The amount is 3 to 50 parts, preferably 3 to 30 parts with respect to 00 parts, and one kind can be used alone or two or more kinds can be used as a mixture.
If the amount is less than 3 parts, the resolution may not be improved. If the amount is more than 50 parts, the film of the pattern may be reduced and the resolution may be reduced.

The resist composition of the present invention further comprises (E)
You a basic compound.

As the basic compound (E), a compound capable of suppressing the rate of diffusion of the acid generated from the acid generator into the resist film is suitable. This suppresses the diffusion rate of acid in the resist film, improving resolution, suppressing changes in sensitivity after exposure, reducing the dependence on the substrate and the environment, and improving the exposure margin and improving the pattern profile. Properties and the like can be improved. As the basic compounds, nitrogen-containing compounds having a mosquito Rubo <br/> hexyl group, nitrogen-containing compounds having a human Dorokishiru group, a nitrogen-containing <br/> compound having a hydroxyphenyl group.

[0088]

[0089]

As the nitrogen-containing compound having a carboxyl group, amino acid derivatives (for example, nicotinic acid, alanine, arginine, aspartic acid, glutamic acid, glycine,
Histidine, isoleucine, glycyl leucine, leucine, methionine, phenylalanine, threonine, lysine, 3-aminopyrazine-2-carboxylic acid, such as methoxy alanine is illustrated, having a nitrogen-containing compound, hydroxyphenyl groups having a heat Dorokishiru group and <br/> a nitrogen-containing compound, 2 hydroxypyridine, aminocresol, ethanolamine, diethanolamine, triethanolamine, diisopropyl propanol amine, Toriisopuro Pano
Lumpur amine, triprolidine propanol amine, 1-aminobutane-2-diol, 1-amino-propan-3-ol,
Examples thereof include 1-aminobutane-2-diol and the like .

The compounding amount of the above-mentioned basic compound is the amount of the acid generator 1
0.001 to 10 parts, preferably 0.01 to 10 parts by weight
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 reduced.

In addition to the above components, a surfactant for improving coating properties and a light absorbing material for reducing the influence of irregular reflection from the substrate can be added to the resist composition of the present invention. . 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, perfluoroalkyl amine oxide, and perfluoroalkyl EO adduct, and the light absorbing material is diaryl sulfo. Oxides,
Examples include diaryl sulfone, 9,10-dimethylanthracene, 9-fluorenone and the like.

A pattern can be formed using the positive resist material of the present invention by employing a known lithography technique. For example, spin coating is performed on a silicon wafer to form a pattern of 0.5 to 2.0 μm. Apply to 8
After prebaking at 0 to 120 ° C, far ultraviolet rays, electron beam,
After exposure to high energy rays such as X-rays, 70 to 12
Post-exposure bake at 0 ° C for 30 to 200 seconds (P
EB) and then developing with an aqueous alkali solution. In addition, the material of the present invention is most suitable for fine patterning using 254 to 193 nm far ultraviolet rays and an electron beam among high energy rays.

[0095]

The chemically amplified positive resist material of the present invention is sensitive to high energy rays such as far ultraviolet rays, electron beams and X-rays, especially KrF excimer laser, and has excellent sensitivity, resolution and plasma etching resistance. Moreover, the heat resistance of the resist pattern is excellent. Further, the pattern is unlikely to be overhanging, and has excellent dimensional controllability. Therefore,
The chemically amplified positive resist material of the present invention can be a resist material having a small absorption at the exposure wavelength of a KrF excimer laser due to these characteristics, and has high resolution, is fine and is perpendicular to the substrate. A simple pattern can be easily formed, and 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. Was charged, the flask was replaced with nitrogen, and the mixture was reacted at 90 ° C. for 5 hours to carry out a polymerization reaction. After completion of the polymerization reaction, the obtained polymer was washed with methanol and dried to obtain 90 g of a powder solid. The obtained powder solid was a polymer represented by the following chemical 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 methylene peak 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)
Was as shown in Table 1.

[Synthesis Examples 2 and 3] In Synthesis Example 1, p-
Poly2 was obtained 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. Was obtained.

The structure of the obtained polymer is represented by the following formula Po
ly2,3, each weight average molecular weight,
The molecular weight distribution was as shown in Table 1.

[Synthesis Example 4] Monodisperse poly (p-1-ethoxyethoxystyrene-p
-Tert-butoxycarbonyloxystyrene-p-
In the synthetic polymerization of hydroxystyrene), 700 ml of tetrahydrofuran was used as a solvent in a 2 L flask, and 7 × sec-butyllithium was used as an initiator.
10 ^-3 mol was charged. The mixed solution is added at -78 ° C with p.
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.

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

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., and the mixture was stirred for 7 hours, poured into water to precipitate a 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. Further, ter in ¹ H-NMR
Since no peak derived from the 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 30 g of ethyl vinyl ether was stirred at 30 ° C.
Was added. After reacting for 16 hours, the mixture was neutralized with concentrated aqueous ammonia, and the neutralized 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 dried under vacuum. From the ¹ H-NMR of the obtained polymer, it was confirmed that the hydrogen atom of the hydroxyl group of polyhydroxystyrene was 27% ethoxyethylated.

Further, 50 g of the obtained partially ethoxyethylated polyhydroxystyrene 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 resulting polymer has a structure represented by the following rational formula POLY4, ¹ H
From NMR, the ratio of ethoxyethylation of hydroxyl group hydrogen atoms of polyhydroxystyrene was 27%, and the ratio of t-BOC conversion of hydroxyl group hydrogen atoms was 8% (Poly4). 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 Monodispersed poly (p-1-ethoxypropoxystyrene)
p-tert-butoxycarbonyloxystyrene-p
Synthesis of -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 pyridinium p-toluenesulfonate was added, followed by stirring at 40 ° C. 27 g of ethoxypropenyl were added. After reacting for 12 hours, the mixture was neutralized with concentrated aqueous ammonia, and the neutralized reaction solution was added dropwise to 10 L of water, whereby a white solid was obtained. After filtration, this was dissolved in 500 ml of acetone, dropped into 10 L of water, filtered, and dried in vacuo. From the ¹ H-NMR of the obtained polymer, it was confirmed that the hydrogen atom of the hydroxyl group of polyhydroxystyrene was ethoxypropylated by 24%.

Further, 50 g of the obtained partially ethoxypropoxylated polyhydroxystyrene was dissolved in 500 ml of pyridine, and the mixture was stirred at 45 ° C. with di-tert-dicarbonate.
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 resulting polymer has a structure represented by the following rational formula, ¹ H-N
From MR, the ethoxypropylation rate of the hydrogen atom of the hydroxyl group of polyhydroxystyrene is 24%, and the t-BOC conversion rate is 11
% (Poly5), and the weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) were as shown in Table 1.

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

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

[0109]

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[0110]

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[0111]

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[0112]

[Table 1]

[Examples 1 to 4 , Comparative Examples 1 to 4, Reference Examples 1 to 30 ] Using the polymer 1 (Poly1) to the polymer 14 (Poly14) obtained in the above synthesis examples as a base resin, the following formula ( PAG1) to an acid generator represented by (PAG8), a dissolution controller represented by the following formulas (DRR1) to (DRR14), and a basic compound in a composition shown in Tables 2 to 4 in diethylene glycol dimethyl ether (DGL).
M), ethyl lactate (EL) / butyl acetate (B
A), propylene glycol monomethyl acetate (P
GMMA) and propylene glycol monoethyl acetate (PGMEA) to prepare a resist material, and each composition was filtered through a 0.2 μm Teflon filter to prepare resist solutions.

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

The resulting resist solution was spin-coated on a silicon wafer and applied to a thickness of 0.8 μm. Next, the silicon wafer was baked at 100 ° C. for 120 seconds using a hot plate. Use an excimer laser stepper (Nikon Corporation, NSR-2005E)
X8A, NA = 0.5) at 60 ° C. at 90 ° C.
After baking for 2 seconds and developing with a 2.38% aqueous solution of tetramethylammonium hydroxide, a positive pattern could be obtained. 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 defined as the optimum exposure amount (Eop), and the minimum line width of the separated line and space at this exposure amount was defined as the resolution of the evaluation resist. The shape of the resolved resist pattern was observed using a scanning electron microscope.

Further, the roughness (edge roughness) of the 0.25 μm line and space was measured with a scanning electron microscope.

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

[0118]

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[0119]

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[0120]

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[0121]

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[0122]

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[0123]

[Table 2]

[0124]

[Table 3]

[0125]

[Table 4]

[Examples 5 to 9 and Reference Examples 31 to 60 ] Using polymers 1 (Poly1) to polymer 14 (Poly14) obtained in the above synthesis examples as base resins, and using the above formulas (PAG1) to (PAG8) The following formulas (DRR1 ′) to (DRR8 ′) and the above formula (DRR1) obtained by chemically reacting an acid labile group with a compound having a phenolic hydroxyl group and an acid generator represented by the following formulas: To (DRR14) and a basic compound in the composition shown in Tables 5 and 6, 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.
Each of the resist solutions was prepared by filtration through a μm Teflon filter.

The obtained resist solution 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 a pattern without unevenness (small edge roughness) could be obtained.

[0129]

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[0130]

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[0131]

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[0132]

[Table 5]

[0133]

[Table 6]

[Brief description of the drawings]

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

──────────────────────────────────────────────────の Continued on the front page (31) Priority claim number Japanese Patent Application No. Hei 7-337901 (32) Priority date December 1, 1995 (Dec. 1, 1995) (33) Priority claim country Japan (JP) Preliminary examination (72) Inventor: Shigehiro Nakura, 28-1, Nishifukushima, Nishigusuku-mura, Nakakushijo-gun, Niigata Shin-Etsu Chemical Industry Co., Ltd. -1 Shin-Etsu Chemical Co., Ltd. Synthetic Technology Laboratory (56) References JP-A-6-273934 (JP, A) JP-A-6-273935 (JP, A) JP-A-6-194842 (JP, A) JP-A-4-211258 (JP, A) JP-A-8-123032 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03F ^7/ 00-7/42

Claims (9)

(57) [Claims] 1. An organic solvent (B) having a repeating unit represented by the following general formula (1) as a base resin and having a weight average molecular weight of 3,000 to 30:
A polymer compound which is a monodisperse polymer having a molecular weight distribution of 1.0 to 1.5 at 000 (Where R ¹ is a hydrogen atom or a methyl group, R ² is a group represented by the following general formula (2), R ³ is a group represented by the following general formula (3), a tetrahydropyranyl group, a tetrahydrofuran A nyl group or a trialkylsilyl group.
p, q, and r are positive numbers and 0.02 ≦ p / (p + q + r) ≦
0.5, 0.01 ≦ q / (p + q + r) ≦ 0.3, 0 <
This is a number that satisfies (p + q) / (p + q + r) ≦ 0.8. a is a positive number from 1 to 3. ) (Wherein 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. (C) an acid generator (E) a nitrogen-containing compound having a carboxyl group,
Nitrogen-fluorinated compounds and hydroxyphenyl groups having a sill group
A chemically amplified positive resist composition comprising a basic compound selected from nitrogen-containing compounds having the formula: 2. R ² is an alkoxyalkyl group and R ³ is t
The chemically amplified positive resist composition according to claim 1, which is an ert-butoxycarbonyl group. 3. The chemically amplified positive resist composition according to claim 1, further comprising (D) a dissolution controlling agent. 4. The dissolution controlling agent of component (D) has a molecular weight of 1
A compound having two or more phenolic hydroxyl groups in the molecule having an average of 10 to 100% of hydrogen atoms of the phenolic hydroxyl groups by an acid labile group.
The chemically amplified positive resist composition according to claim 3, which is a compound substituted by the following ratio. 5. The dissolution controlling agent of the component (D) is a compound having a weight-average molecular weight of more than 1,000 and not more than 3,000 and having a phenolic hydroxyl group in the molecule, and converting the hydrogen atom of the phenolic hydroxyl group into an acid. 0 average overall due to unstable groups
The chemically amplified positive resist composition according to claim 3, which is a compound partially substituted at a ratio of more than 60% and not more than 60%. 6. A compound having a molecular weight of 100 to 1,000 and having two or more phenolic hydroxyl groups in a molecule, wherein the hydrogen atom of the phenolic hydroxyl group is an acid labile group as a dissolution controlling agent of the component (D). 10 to 10 on average as a whole
A compound substituted at a rate of 0% and a weight average molecular weight of 1,
In a compound having a phenolic hydroxyl group in the molecule of more than 3,000 and not more than 3,000, the hydrogen atom of the phenolic hydroxyl group is more than 0% on average as a whole by an acid labile group.
4. The chemically amplified positive resist composition according to claim 3, wherein a compound partially substituted with 0% or less is used in combination. 7. 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 4 or 6, wherein the composition is at least one compound selected from the 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. Or branched alkyl or alkenyl group, or-
(R ¹⁸ ) _s —COOH, and R ¹⁵ is — (CH ₂ ) _t —
(T = 2 to 10), an arylene group having 6 to 10 carbon atoms, a carbonyl group, a sulfonyl group, an oxygen atom or a 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 linear or branched chain having 1 to 8 carbon atoms. alkyl group, an alkenyl group, a phenyl group or a naphthyl group substituted with each hydroxyl, R ¹⁸
Is a linear or branched alkylene group having 1 to 10 carbon atoms. K is an integer of 0 to 5, and s is 0 or 1. m, n, m ′, n ′, m ″, and n ″ each satisfy m + n = 8, m ′ + n ′ = 5, m ″ + n ″ = 4, and at least 1 It is a number having two hydroxyl groups. α is a number such that the molecular weight of the compounds of the formulas (13) and (14) is 100 to 1,000. ) 8. The weight average molecular weight exceeding 1,000,
The chemical amplification according to claim 5 or 6, wherein the compound having a phenolic hydroxyl group in the molecule of not more than 000 is one or more compounds selected from compounds having a repeating unit represented by the following general formula (17). Positive resist material. Embedded image (Wherein, R represents an acid labile group, and c and d are numbers satisfying 0 ≦ c / (c + d) ≦ 0.6, respectively) 9. The chemically amplified positive resist composition according to claim 1, wherein the acid generator (C) is an onium salt.