JPH09124598A - Succinimide derivative, its production and use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject compound usable as an acid generator for resist composition containing an alkali soluble resin having a protecting group capable of cleaving by action of an acid and provide a resist composition using the derivative. SOLUTION: This compound is N-(10-camphorsulfonyloxy)succinimide represented by the formula. The compound is produced by reacting N- hydroxysuccinimide with 10-camphorsulfonic acid, its salt or halide. The compound of the formula is used as an acid generator and blended with an alkali- soluble resin having a protecting group capable of cleaving by action of an acid to provide the objective resist composition. The resist composition containing the compound of the formula as the acid generator is excellent in various characteristics such as heat resistance, film-leaving ratio, coating property, profile, sensitivity and resolution and improved in delay effect and adhesiveness of pattern.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel succinimide derivative, a method for producing the same, and its application to the resist field.

[0002]

2. Description of the Related Art In recent years, with the increase in the degree of integration of semiconductor integrated circuits, formation of quarter-micron patterns has been required. In particular, excimer laser lithography using krypton fluoride (KrF) or argon fluoride (ArF) as a light source has attracted attention because it enables production of 64 MDRAM and 256 MDRAM. Conventionally, near-ultraviolet rays have been mainly used in the lithography process,
With the change of the light source, the resist is required to have the following new performances in addition to the conventional performances such as heat resistance, residual film ratio, and profile. a) High sensitivity to KrF and ArF excimer laser light sources, and b) High resolution.

Under these circumstances, so-called chemically amplified resists utilizing the chemical amplification effect of acid catalysts have been proposed. The chemically amplified resist expresses solubility in an exposed portion in an alkali developing solution by a reaction using an acid generated from an acid generator upon irradiation with a catalyst, whereby a positive resist is obtained.

For the chemically amplified positive resist, a resin in which the phenolic hydroxyl group of polyvinylphenol is protected by a group capable of leaving by the action of an acid has heretofore been often used. However, a resist using such a resin generally has a drawback that it is easily affected by the environment. In particular, it is known that the performance greatly changes depending on the standing time before the heat treatment in the process (Post Exposure Bake: hereinafter sometimes abbreviated as PEB) in which heat treatment is performed after the exposure to promote the elimination reaction of the protective group. There is. This phenomenon is also called a time delay effect, etc., and the resolution is deteriorated, and the film-tension phenomenon (T-shaping) appears in the pattern after development, and the reproducibility of dimensions is impaired. .

It is thought that the cause of such a phenomenon is that a basic component such as ammonia or N-methylpyrrolidone existing in the environment atmosphere for lithography adheres to the resist coating film to deactivate the acid generated. There is. For example, it is known that even if the concentration of ammonia in the air is as low as about 20 ppb, the profile of the pattern obtained by performing PEB after exposure for 30 minutes after exposure is remarkably T-shaped.

Further, in the formation of quarter-micron patterns, there is a problem that etching defects are likely to occur due to tilting or flying of small patterns.

[0007]

The object of the present invention is to exert excellent effects when used as an acid generator of a resist composition containing an alkali-soluble resin having a protective group capable of being cleaved by the action of an acid. It is to manufacture and provide a novel compound.

The present invention also uses such a compound, while maintaining various properties such as heat resistance, residual film rate, coating property, and profile at a high level, excellent sensitivity and resolution, and delay effect and pattern adhesion. It is also an object to provide a resist composition having improved properties.

As a result of intensive studies aimed at achieving such an object, the inventors of the present invention found a new succinimide compound and formulated it with an alkali-soluble resin having a protective group capable of being cleaved by the action of an acid. The resist composition obtained above is excellent in sensitivity and resolution while maintaining various properties such as heat resistance, residual film rate, coating property, and profile at a high level, and the delay effect and pattern adhesion are improved. Found and completed the present invention.

[0010]

That is, the present invention provides N- (10-camphorsulfonyloxy) succinimide represented by the formula (I).

[0011]

The present invention also provides the reaction of N-hydroxysuccinimide with 10-camphorsulfonic acid, its salt or halide to form N- (10 of formula (I).
-Providing a method for producing camphorsulfonyloxy) succinimide, providing an acid generator containing the N- (10-camphorsulfonyloxy) succinimide as an active ingredient, and further providing the acid generator by the action of an acid. Also provided is a resist composition formulated with an alkali-soluble resin having a cleavable protecting group.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION N- (10-
Camphorsulfonyloxy) succinimide is N-
It can be produced by reacting hydroxysuccinimide with 10-camphorsulfonic acid, its salt or halide. The 10-camphorsulfonic acid, its salt or halide used here may be an optically active substance or a racemate. Among 10-camphorsulfonic acid, its salts and halides, 10-camphorsulfonyl halide is particularly preferably used, which is preferably reacted with N-hydroxysuccinimide in the presence of a basic catalyst. Examples of the halogen that constitutes the 10-camphorsulfonyl halide include fluorine, chlorine, bromine, iodine and the like.

In this reaction, 10-camphorsulfonic acid, its salt or halide is used in a molar ratio of 0.7 to 1.5, more preferably 1.1 to 1.2, with respect to N-hydroxysuccinimide. Is preferred. If the molar ratio is less than 0.7, unreacted N-hydroxysuccinimide remains, and if the molar ratio exceeds 1.5, unreacted 10-camphorsulfonic acid or its derivative remains in a large amount.
Purification after the reaction becomes difficult.

Examples of the basic catalyst include aliphatic amines such as triethylamine, cyclic amines such as pyridine, inorganic bases such as sodium hydrogencarbonate, sodium carbonate and potassium carbonate. Among them, triethylamine and pyridine are particularly preferable. The organic amines of are preferably used.

N-hydroxysuccinimide and 10-
The reaction with camphorsulfonic acid, its salt or halide is preferably carried out in a polar solvent. As the polar solvent used here, acetone, tetrahydrofuran, 1,4
-One or more hydrophilic solvents such as dioxane, 1,3-dioxolane, dimethylformamide, acetonitrile, γ-butyrolactone, dimethylsulfoxide,
Examples thereof include one or more hydrophobic solvents such as dichloromethane and chloroform, water including ion-exchanged water and distilled water. The polar solvent is preferably used in an amount of 2 to 10 times by weight, more preferably 4 to 8 times by weight, based on the total amount of N-hydroxysuccinimide, which is a reaction raw material, and 10-camphorsulfonic acid, or a salt or halide thereof. . If the amount of the solvent is too large, the reaction time is prolonged. If the amount is too small, problems such as solubility limitation and stirring power tend to occur.

This reaction is usually carried out at a temperature in the range of 20 to 50 ° C. If the temperature is too high, side reactions easily occur, and if the temperature is too low, the reaction time becomes long. The reaction time is usually about 0.5 to 5 hours.

After completion of the reaction, the desired product, N- (10-camphorsulfonyloxy) succinimide, can be taken out by performing an appropriate operation. In particular, it is preferable to dissolve the product in a solvent having a solubility in water of 9 g / 100 g or less and perform water separation to reduce the metal content. Here, that the solubility in water is 9 g / 100 g or less means that the maximum amount soluble in 100 g of water at 20 ° C. is 9 g or less. Examples of such a solvent include, for example,
Examples include toluene, ethyl acetate, methylene chloride, and n-heptane.

The N- (10-camphorsulfonyloxy) succinimide produced by the reaction or having the metal content reduced as described above can be crystallized from a suitable solvent. As the crystallization solvent used here, for example, a halogenated hydrocarbon alone such as carbon tetrachloride or chloroform or a mixed solvent mainly containing it, an aliphatic or alicyclic hydrocarbon such as n-heptane or cyclohexane, Examples thereof include a mixed solvent with an aromatic hydrocarbon such as benzene, toluene and xylene. The crystallization temperature is preferably 40 ° C. or lower, more preferably 25 ° C. or lower.

The N- (10-camphorsulfonyloxy) succinimide thus obtained has an asymmetric carbon atom as is apparent from the formula (I), and can be an optically active substance or a racemate. This compound is useful as an acid generator for a resist composition, particularly as an acid generator used in a resist composition in combination with an alkali-soluble resin having a protective group capable of being cleaved by the action of an acid.

The alkali-soluble resin constituting the resist composition has a protective group which can be cleaved by the action of acid. The base polymer is preferably one having an aryl group having a hydroxyl group introduced therein or one having a carboxyl group. Specifically, phenol novolac resin; cresol novolac resin; xylenol novolac resin; vinyl phenol resin; isopropenyl phenol resin; vinyl phenol and (meth) acrylic acid or its derivative, acrylonitrile, styrene or its derivative, etc. Copolymer of isopropenylphenol and (meth) acrylic acid or its derivative, acrylonitrile, styrene or its derivative, etc .; Styrene or its derivative and acrylic resin, methacrylic resin, acrylic acid, methacrylic acid, maleic acid, Copolymers with maleic anhydride, acrylonitrile and the like; compounds containing silicon in these polymer chains and the like can be mentioned.

At least a part of the hydroxyl group or the carboxyl group in these base polymers is protected by a protecting group capable of being cleaved by the action of an acid, that is, at least a part of the hydrogen atom in the hydroxyl group or the carboxyl group is protected by such protection. Those substituted with a group can be the alkali-soluble resin in the resist composition of the present invention. As the protective group, those having the following structures are particularly preferable.

[0023]

In the formula, n represents an integer of 4 to 6; R ¹ and R
⁴ , R ⁷ and R ¹¹ are each independently linear alkyl,
Represents branched alkyl, cyclic alkyl, alkenyl, aryl or aralkyl; R ² , R ³ , R ⁵ , R ⁶ ,
R ⁹ , R ¹⁰ and R ¹² are each independently hydrogen, linear alkyl, branched alkyl, cyclic alkyl, alkenyl,
R ¹³ represents aryl or aralkyl; R ⁸ represents hydrogen, linear alkyl, branched alkyl, cyclic alkyl, alkenyl, aryl, aralkyl or alkoxy; R ¹³
Represents hydrogen, linear alkyl, branched alkyl, cyclic alkyl, alkenyl, aryl or aralkyl,
R ¹⁴ represents straight chain alkyl, branched alkyl, cyclic alkyl, alkenyl, aryl or aralkyl, or R ¹³ and R ¹⁴ combine to form an unbranched alkylene having 3 to 6 carbon atoms.

Here, the straight-chain alkyl includes, for example, those having 1 to 5 carbon atoms, the branched alkyl includes, for example, those having 3 to 8 carbon atoms, and the cyclic alkyl includes, for example, Those having 5 to 16 carbon atoms are mentioned,
This may be cycloalkylalkyl, in addition to cycloalkyl, and as alkenyl, for example, has 2 to 2 carbon atoms.
7 are mentioned, examples of the aryl include those having 6 to 16 carbon atoms, typically phenyl or naphthyl, and examples of the aralkyl are, for example, 7 to 7 carbon atoms.
Examples thereof include those having 16 carbon atoms, and examples of the alkoxy include those having 1 to 5 carbon atoms. These groups may have a substituent, and examples of the group which may be substituted with linear alkyl, branched alkyl or alkenyl include halogen and the like, and cycloalkanes constituting cyclic alkyl. Examples of the group which may be substituted on the ring include halogen and the like, and examples of the group which may be substituted on the aromatic ring such as benzene ring and naphthalene ring forming aryl or aralkyl include halogen and nitro. Further, of course, a hydrocarbon group such as alkyl may be bonded to the cycloalkane ring or the aromatic ring here within the range of the number of carbon atoms.

The resist composition of the present invention contains the above-described alkali-soluble resin and acid generator, but if necessary, an electron donor, a dissolution inhibitor,
It may also contain the usual additives used in this field, such as a sensitizer, a dye and an adhesion improver. The resist composition contains the alkali-soluble resin in the range of 20 to 90% by weight and the acid generator in the range of 0.1 to 20 based on the total solid content.
It is preferably blended in the range of% by weight.

The resist composition of the present invention is usually prepared by mixing each of the above components with a solvent to prepare a resist solution so that the total solid content concentration is 10 to 50% by weight, and applying the resist solution onto a substrate such as a silicon wafer. To be done. The solvent used here may be any solvent that dissolves each component, and may be a solvent generally used in this field. For example, ethyl cellosolve acetate, methyl cellosolve acetate, propylene glycol monomethyl ether acetate, glycol ether esters such as propylene glycol monoethyl ether acetate, ethyl cellosolve,
Methyl cellosolve, propylene glycol monomethyl ether, propylene glycol monoethyl ether, glycol mono or diethers such as diethylene glycol dimethyl ether, esters such as ethyl lactate, butyl acetate, ethyl pyruvate, cyclic esters such as γ-butyrolactone, 2-heptanone, cyclohexanone, ketones such as methyl isobutyl ketone,
Examples thereof include aromatic hydrocarbons such as xylene.
These solvents can be used alone or in combination of two or more.

[0028]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the examples, percentages and parts representing the content or the used amount are based on weight unless otherwise specified.

Synthesis Example 1 A 200 ml four-necked flask was charged with 7.41 g of N-hydroxysuccinimide, 18.13 g of (±) -10-camphorsulfonyl chloride, and 127.6 of acetonitrile.
After charging 9 g and stirring at 25 ° C. for 30 minutes, 7.89 g of triethylamine was added dropwise over 20 minutes. After stirring for another 3 hours, the mixture was filtered, and the filtered substance was filtered with acetonitrile 36.6.
After washing with 3 g, the filtrate and the washing solution were combined, ethyl acetate (367.88 g) was added thereto, and then washed with 180.66 g of distilled water three times and then concentrated. Acetone 1 to this concentrate
1.97 g was added, and then carbon tetrachloride was added at reflux 119.66.
g, and cooled to 25 ° C or lower. Precipitated crystals were filtered, and 27.37 g of the obtained wet cake was dried with hot air at 40 ° C. for one day to obtain 19.41 g of N- (10-camphorsulfonyloxy) succinimide.

Mass spectrometry: SIMS (FAB) 330 (M + H) ^{+ 1} H-NMR (dimethyl sulfoxide) δ (ppm): 0.8
3 (s, 3H); 1.02 (s, 3H); 1.41-1.50 (m, 1H); 1.60-1.
70 (m, 1H); 1.93-2.03 (m, 2H); 2.09-2.13 (m, 1H);
2.16-2.26 (m, 1H); 2.34-2.44 (m, 3H); 2.80 (s, 4H);
3.79-3.96 (m, 2H). ¹³ C-NMR (dimethyl sulfoxide) δ (ppm): 1
9.01, 25.14, 25.38, 26.14, 41.76, 42.28, 47.96, 51.
32, 57.88, 170.30, 212.84.

Synthesis Example 2 In a 200 ml four-necked flask, 17.26 g of N-hydroxysuccinimide, 34.90 g of (+)-10-camphorsulfonyl chloride and 1,4-dioxane 26 were added.
After charging 0.81 g and stirring at 25 ° C. for 30 minutes, 15.03 g of triethylamine was added dropwise over 30 minutes. After stirring for another 4 hours, toluene 661.2 was added to the reaction mass.
1g was added and 0.5% oxalic acid aqueous solution 335.61g
Was added to wash, and after liquid separation, it was washed 6 times with 335.61 g of distilled water and then concentrated. Ethyl acetate 23.39 in this concentrate
g, and after heating to 60 ° C., n-heptane 79.5
A mixed solution of 3 g and 154.37 g of toluene was added, and the mixture was cooled to 25 ° C or lower. The precipitated crystals were filtered, and the obtained wet cake was dried with hot air at 40 ° C. for one day to obtain 34.52 g of N- (10-camphorsulfonyloxy) succinimide.

Application Example 1 Polymer 13.5 obtained by the method described in JP-A-5-181279, in which 20 mol% of the hydroxyl groups in poly (p-vinylphenol) are tert-butoxycarbonylmethyl etherified. Part, N- (10-camphorsulfonyloxy) succinimide 1.2 parts, and 2-hydroxycarbazole (Aldrich) 0.405 as an electron donor.
Part was mixed and dissolved in 66 parts of propylene glycol monomethyl ether acetate and filtered through a fluororesin filter having a pore size of 0.2 μm to obtain a resist solution A.

On a silicon wafer washed by a conventional method,
The resist solution A was applied using a spin coater so that the film thickness after drying would be 0.7 μm. Next, this silicon wafer was prebaked at 100 ° C. for 1 minute on a hot plate. The coating film after prebaking was exposed through a patterned chrome mask using a KrF excimer laser stepper ["NSR-1755 EX8A" manufactured by Nikon Corp., NA = 0.45] having an exposure wavelength of 248 nm. The exposed wafer is 95 ° C on a hot plate.
Post baking (PEB) was performed for 90 seconds. This is 2.38% of tetramethylammonium hydroxide
Development with an aqueous solution gave a positive pattern. The obtained positive pattern was evaluated as follows, and the results are shown in Table 1.

Sensitivity: The cross section of 0.3 μm line and space was observed with a scanning electron microscope, and the sensitivity (effective sensitivity) was obtained from the exposure amount at which the line and space at the best focus became 1: 1.

Resolution: The minimum line-and-space width that allows separation without film loss at the exposure dose of effective sensitivity is defined as the resolution.

Profile: The cross-sectional shape of a line and space of 0.3 μm at the exposure amount of effective sensitivity was observed with a scanning electron microscope.

Small pattern collapse: The degree of collapse of the resist was observed, and evaluation was made on a three-point scale, in which no collapse occurred, ◯, partially collapsed, Δ, and almost collapsed, x.

The above items were also evaluated for the post-baked product that had been left for 1 hour after exposure.

Comparative Example 1 Instead of N- (10-camphorsulfonyloxy) succinimide in Application Example 1, the following formula was used.

[0040]

Compound represented by (Midori Kagaku Co., Ltd.)
A resist solution B was obtained in the same manner as in Application Example 1 except that 0.405 part was used. This resist solution B was evaluated in the same manner as in Application Example 1, and the results are also shown in Table 1.

[0042]

[Table 1] ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Sensitivity resolution profile^* Small pattern collapse ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Application example 1 Immediately after exposure PEB 28 mJ / cm^Two 0.29 μm (a) ○ 1 hour after exposure PEB 32 mJ / cm^Two 0.30 μm (a) ○ ──────────────────────────────────── Comparative Example 1 Immediately after exposure PEB 122 mJ / cm^Two 0.35 μm (b) △ After 1 hour of exposure PEB No resolution No resolution No resolution No resolution ━━━━━━━━━━━━━━━━━━━━━━━━ ━━━━━━━━━━━━━ ^* The profiles (a) and (b) indicate that they have the shapes of (a) and (b) of FIG. 1, respectively.

[0043]

INDUSTRIAL APPLICABILITY The N- (10-camphorsulfonyloxy) succinimide of the present invention is used for a resist acid generator, particularly for a resist composition containing an alkali-soluble resin having a protective group capable of being cleaved by the action of an acid. It is useful as an acid generator. And, a resist composition using this compound as an acid generator has various properties such as heat resistance, residual film rate, coating property and profile maintained at a high level, and also has excellent sensitivity and resolution, and has a retarding effect and a pattern. The adhesion of is improved.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of profiles observed in an application example and a comparative example.

[Explanation of symbols]

 (A) Profile observed in Application Example 1 (b) Profile observed in Comparative Example 1

Claims (8)

[Claims] (1) Formula (I) N- (10-camphorsulfonyloxy) represented by
Succinimide. 2. N-hydroxysuccinimide and 10-
The method for producing N- (10-camphorsulfonyloxy) succinimide according to claim 1, which comprises reacting with camphorsulfonic acid, a salt thereof, or a halide. 3. The method according to claim 2, wherein the reaction is carried out using 10-camphorsulfonyl halide in the presence of a basic catalyst. 4. The method according to claim 2, wherein the reaction is carried out in a polar solvent. 5. The method according to any one of claims 2 to 4, wherein after the reaction, the product is dissolved in a solvent having a water solubility of 9 g / 100 g or less, and water separation is performed to reduce the metal content. . 6. The method according to claim 2, wherein the product is crystallized from a halogenated hydrocarbon solvent or a mixed solvent of an aliphatic or alicyclic hydrocarbon and an aromatic hydrocarbon. . 7. An acid generator comprising the N- (10-camphorsulfonyloxy) succinimide according to claim 1 as an active ingredient. 8. A resist composition comprising an alkali-soluble resin having a protective group capable of being cleaved by the action of an acid, and the acid generator according to claim 7.