KR100431018B1 - Succinimide derivatives, preparation methods thereof and uses thereof - Google Patents

Abstract

The present invention relates to N- (10-camphorsulfonyloxy) -succinimide of formula (1) which can be obtained by reacting N-hydroxysuccinimide with 10-camphorsulfonic acid, salts thereof or halides thereof. It is about.

[Formula 1]

Using the above compound as an acid generating agent, a resist composition can be obtained comprising an alkali-soluble resin having a protecting group removable by the action of an acid, which resist composition is heat resistant, the ratio of the remaining film thickness after development, the film It has excellent thickness uniformity, profile, light speed and resolution, and improves time delay effect and pattern adhesion.

Description

Succinimide derivatives, preparation methods thereof and uses thereof

The present invention relates to novel succinimide derivatives, methods for their preparation and their application in the field of resists.

Recently, there is a demand for forming a 1/4 mu pattern with an increased integration rate of semiconductor integrated circuits. In particular, attention has been focused because excimer laser lithography using krypton fluoride (KrF) or argon fluoride (ArF) as the light source can produce 64 MARAM and 256MDRAM. Near-ultraviolet light has typically been used mainly in lithography processes. However, as the light source changes, the following properties have been newly requested in addition to the commonly required properties such as heat resistance, remaining film thickness ratio after development (film retention), profile and other properties.

a) high luminous flux for KrF and ArF excimer laser light sources and

b) high resolution.

Under these circumstances, resist forms commonly referred to as chemically amplified resists have been proposed that utilize the chemical amplification effect of acid catalysts. The solubility of the exposed portions of the alkaline developer in the chemically amplified resist is realized by a reaction catalyzed by an acid generated from the acid generator by irradiation, which provides a positive resist.

Typically, in the preparation of chemically amplified positive resists, polyvinylphenols in which phenolic hydroxyls are protected by groups removable by the action of acids have been used. Resists using such resins have defects susceptible to environmental influences. In particular, in the step of carrying out the removal of the protective group by heat treatment after exposure to light (Post Exposure Bake; hereinafter referred to as PEB), the properties are known to vary considerably with the settling period before heat treatment. This phenomenon is often referred to as a time-lag effect and can cause degradation in resolution, T-top formation (T-molding) of patterns after development and poor regeneration of critical dimensions.

This phenomenon is considered to be due to the deactivation of the acid caused by basic substances such as ammonia and N-methylpyrrolidone which are present in the surrounding atmosphere and in contact with the coating film when lithography is performed. For example, even when the concentration of ammonia in the atmosphere is as low as about 20 ppb, it is known that the pattern obtained by PEB performed 30 minutes after exposure has a profile with significant T-forming.

In addition, there is a problem that inferior etching caused by the installation or peeling of a small pattern is likely to occur in the production of the 1 / 4μ pattern.

It is an object of the present invention to provide a novel compound which exhibits excellent effects when used as an acid generator for a resist composition comprising an alkali-soluble resin having a protecting group that can be removed by the action of an acid.

Another object of the present invention is to use the compound, the light speed and resolution is excellent, the time delay effect and the pattern adhesion is improved while the heat resistance, the ratio of the remaining film thickness after development, the uniformity and profile of the film thickness, etc. It is to provide a resist composition that is maintained at a level.

As a result of intensive research, the inventors of the present invention have successfully discovered a novel succinimide compound, and the resist composition containing the compound together with an alkali-soluble resin having a protecting group that can be removed by the action of an acid has a high light rate and The present invention has been completed by revealing that the resolution is excellent and the time delay effect and the adhesion of the pattern are maintained, while the heat resistance, the ratio of the residual film thickness after development, the uniformity of the film thickness, the profile, and the like are maintained at a high level.

The present invention provides N- (10-camphorsulfonyloxy) -succinimide of formula (1).

[Formula 1]

The present invention also provides a process for preparing N- (10-camphorsulfonyloxy) -succinimide of Formula 1 by reacting N-hydroxysuccinimide with 10-camphorsulfonic acid, salts thereof or halides thereof. Way; Acid generators comprising N- (10-camphorsulfonyloxy) -succinimide as active ingredient; And also the above-mentioned acid generator with an alkali-soluble resin having a protecting group removable by the action of an acid.

N- (10-camphorsulfonyloxy) -succinimide of Formula 1 may be obtained by reacting N-hydroxysuccinimide with 10-camphorsulfonic acid, salts thereof or halides thereof. As used herein, 10-camphorsulfonic acid, salts thereof, or halides thereof are optically active or racemic. Of the 10-camphorsulfonic acid, salts thereof or halides thereof, 10-camphorsulfonyl halides, which preferably react with N-hydroxysuccinimide, preferably in the presence of a basic catalyst, are particularly preferred. Examples of halogen as a member of 10-camphorsulfonyl halide include fluorine, chlorine, bromine and iodine.

In this reaction, 10-camphorsulfonic acid, its salt or halide thereof is preferably used in a molar ratio of 0.7 to 1.5, more preferably 1.1 to 1.2, based on N-hydrosuccinimide. When the molar ratio is less than 0.7, unreacted N-hydrosuccinimide remains, and when the molar ratio is 1.5 or more, unreacted 10-camphorsulfonic acid or a derivative thereof remains, and in any case, a large amount remains. And purification after the reaction becomes difficult.

Examples of basic catalysts used in the reaction of 10-calporsulfonyl halides with N-hydrosuccinimide include aliphatic amines (eg triethylamine), cyclicamines (eg pyridine) and inorganic bases (eg carbonic acid) Sodium hydrogen, sodium carbonate or potassium carbonate). Among them, organic amines such as triethylamine and pyridine are preferred.

The reaction of N-hydrosuccinimide with 10-camphorsulfonic acid, salts thereof or halides thereof is preferably carried out in a polar solvent. Examples of polar solvents used herein include one or more hydrophilic solvents, such as acetone, terahydrofuran, 1,4-dioxane, 1,3-dioxolane, dimethylformamide, acetonitrile, γ-butyrolactone and dimethyl Sulfoxide), one or more hydrophobic solvents (eg, dichloromethane and chloroform), and water including ion exchanged water and distilled water. The polar solvent is used at preferably 2 to 10 times, more preferably 4 to 8 times the total weight of the reaction material comprising N-hydrosuccinimide and 10-camphorsulfonic acid, salts thereof or halides thereof. do. When the amount of the solvent is too large, the reaction time is longer, and when the amount of the solvent is too small, problems related to dissolution or stirring torque may occur.

The reaction can usually be carried out in a temperature range of 20 to 50 ° C. If the temperature is too high, side reactions may increase, and if the temperature is too low, the reaction time will be too long. Usually the reaction time is about 0.5 to 5 hours.

Free acids, especially sulfonic acids such as 10-camphorsulfonic acid derived from the starting material 10-camphor-sulfonyl halide, can provide undesirable effects for the purposes of the present invention, It is preferable to subject the reaction product containing N- (10-camphorsulfonyloxy) succinimide formed by the reaction with 10-camphorsulfonyl halide to remove free acid. In this way, N- (10-camphorsulfonyloxy) succinimide can be produced in which no sulfonic acid remains and an acid generator which is effective in suppressing retardation effect and film formation can be obtained more continuously.

After the reaction is completed, it is preferable to remove the salt of the basic catalyst formed by the reaction, if necessary, and then perform a treatment for removing the sulfonic acid. The treatment to remove the sulfonic acid may be any treatment as long as it allows to remove the sulfonic acid that contaminates the reaction product, for example, a solution comprising the reaction product in a hydrophobic organic solvent is weaker than the acidity of the sulfonic acid. A method comprising washing with an aqueous solution comprising a neutral salt of an acid having an acidity. If the reaction is carried out in a hydrophilic solvent for this purpose, a hydrophobic organic solvent is added to the solution after the reaction or to a solution from which the salt of the basic catalyst is removed. Preferred organic solvents are solvents having a solubility in water of 9 g / 100 g or less, and 10-camphorsulfonyloxy succinimide can be appropriately dissolved. As used herein, the expression "solvent having a solubility in water of 9 g / 100 g or less" means that the maximum solubility in 100 g of water at 20 ° C is 9 g or less. Examples of such solvents include toluene, ethyl acetate, methylene chloride and n-heptane.

Acids whose acidity is weaker than sulfonic acid include, for example, acetic acid. Neutral salts used in the treatment to remove sulfonic acids include, for example, sodium acetate, potassium acetate and ammonium acetate, of which sodium acetate is preferred. When neutral salts of acids with lower acidity than sulfonic acids are used, the amount of such salts is at least 0.01 moles, preferably 0.05 to 0.15 moles (based on 10-camphorsulfonyl halide). It is not preferable to use too much neutral salt because metal salts and the like remain in N- (10-camphorsulfonyloxy) succinimide.

The treatment for removing the sulfonic acid is carried out after washing with an aqueous solution of a neutral salt of an acid whose acidity is weaker than the sulfonic acid described above, followed by a dilute aqueous acid solution, for example an aqueous acetic acid or oxalic acid solution having a concentration of about 0.1 to 1% by weight. Washing with and further washing with water may be involved. This can minimize the content of coexisting metals.

The N- (10-camphorsulfonyloxy) succinimide produced by the above reaction can be separated using a separation means suitable for separation after completion of the reaction. If the above treatment, i.e., no sulfonic acid removal treatment, is performed, the product is preferably dissolved in a solvent having a solubility in water of 9 g / 100 g or less, and the solution is stirred with water to minimize the metal content.

N- (10-camphorsulfonyloxy) succinimide formed by the above reaction or treated as described above can be crystallized from a suitable solvent. Examples of solvents for crystallization are halogenated hydrocarbons (e.g. carbon tetrachloride or chloroform as such or as a main component in a mixed solvent) or aliphatic or cycloaliphatic hydrocarbons (e.g. n-heptane or cyclohexane) and aromatic hydrocarbons (e.g. benzene, Mixed solvents of toluene or xylene). The crystallization temperature is preferably 40 ° C. or lower, especially 25 ° C. or lower.

The N- (10-camphorsulfonyloxy) succinimide obtained in this way has an asymmetric carbon atom as shown in Formula 1 and may be in optically active form or racemic form. This compound is useful as an acid generator, in particular as an acid generator for use in resist compositions comprising alkali-soluble resins having a protecting group that can be removed by the action of an acid.

Alkali-soluble resins as components of the resist composition of the present invention have a protecting group that can be removed by the action of an acid. Preferred base polymers to which protective groups are introduced are polymers with aryl groups to which hydroxy groups or carboxyl groups are introduced. Specific examples of the base polymer include phenol novolak resins; Cresol novolac resins; Xylenol novolac resins; Vinylphenol resins; Isopropenylphenol resin; Copolymers such as vinylphenol or isopropenylphenol and (meth) acrylic acid or derivatives thereof, acrylonitrile, styrene or derivatives thereof; Styrene or derivatives thereof and copolymers such as acrylic resins, methacrylic resins, acrylic acid, methacrylic acid, maleic acid, maleic anhydride, acrylonitrile and compounds comprising silicon in the chains of the foregoing polymers.

The alkali-soluble resin in the resist composition according to the present invention may be a resin in which at least some of the hydroxyl groups or carboxyl groups in these base polymers are blocked by protective groups, which can be removed by the action of an acid. In other words, at least some of the hydrogen atoms in the hydroxyl groups or carboxyl groups in these base polymers may be resins substituted by the above protecting groups. Preferred protection groups

Chemical formula

[Where n is an integer of 4 to 6; R ¹ , R ⁴ , R ⁷ and R ¹¹ are each independently straight chain alkyl, branched chain 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, straight chain alkyl, branched chain alkyl, cyclic alkyl, alkenyl, aryl or aralkyl; R ⁸ is hydrogen, straight chain alkyl, branched chain alkyl, cyclic alkyl, alkenyl, aryl, aralkyl or alkoxy; R ¹³ is hydrogen, straight chain alkyl, branched chain alkyl, cyclic alkyl, alkenyl, aryl or aralkyl; R ¹⁴ is straight alkyl, branched alkyl, cyclic alkyl, alkenyl, aryl or aralkyl; R ¹³ and R ¹⁴ together form a branched alkylene having 3 to 6 carbon atoms.

Examples of straight chain alkyl include straight chain alkyl having 1 to 5 carbon atoms, examples of branched alkyl include branched alkyl having 3 to 8 carbon atoms, and examples of cyclic alkyl include 5 to 5 carbon atoms including cycloalkyl and cycloalkylalkyl. 16 cyclic alkyls. Examples of alkenyl include alkenyl having 2 to 7 carbon atoms, examples of aryl include aryl having 6 to 16 carbon atoms, typically phenyl or naphthyl, and examples of aralkyl include aralkyl having 7 to 16 carbon atoms. Include. Examples of alkoxy include alkoxy having 1 to 5 carbon atoms. These groups may have substituents. Examples of substituents that may be present on straight chain alkyl, branched chain alkyl or alkenyl include halogen. Examples of substituents that may be present on cycloalkane rings as cyclic alkyls include halogens, and examples of substituents on aromatic rings such as benzene rings or naphthalene rings as aryl or aralkyl include halogens and nitros. Hydrocarbon groups such as alkyl may be substituted with a cycloalkane ring or an aromatic ring within the above-mentioned carbon number range.

The resist composition according to the present invention contains an alkali soluble resin and an acid generator, and may further include additives commonly used in the art, such as electron donors, dissolution inhibitors, photosensitizers, dyes and adhesion promoters, if necessary. The resist composition preferably comprises an alkali soluble resin in the range of 20 to 90% by weight and an acid generator of 0.1 to 20% by weight based on the total weight of the solid component.

The resist composition of the present invention is prepared by mixing the above components in a solvent such that the total concentration of the solid components is 10 to 50% by weight. It is applied to a support such as a silicon wafer. The solvent used herein may be any solvent as long as it dissolves all components and can be any solvent conventionally used in the art. For example, glycol ether esters (eg, ethyl cellosolve acetate, methyl cellosolve acetate, propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate); Glycol mono- or di-ethers (eg ethyl cellosolve, methyl cellosolve, propylene glycol monomethyl ether, propylene glycol monoethyl ether and diethylene glycol dimethyl ether); Esters such as ethyl lactate, butyl acetate and ethyl pyruvate; Cyclic esters (eg γ-butyrolactone); Ketones (eg 2-heptanone, cyclohexanesilver and methyl isobutyl ketone); And aromatic hydrocarbons (eg xylene). These solvents can be used independently or as a mixture of two or more.

The present invention will be listed in more detail in the examples, but these examples should not be considered as being limited to the scope of the invention. In the examples, the percentages and parts in describing the amounts and amounts are by weight unless otherwise indicated.

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 127.69 g of acetonitrile, and stirred at 25 ° C. for 30 minutes, followed by 7.89 g ethylamine is added over 20 minutes. The mixture is stirred for an additional 3 hours and then filtered, and the filter cake is washed with 36.63 g of acetonitrile. 367.88 g of ethyl acetate is added to the combined filtrate and washings and the mixture is washed three times with 180.66 g of distilled water and concentrated. Add 11.97 g of acetone to the concentrate and add 119.66 g of carbon tetrachloride while refluxing the mixture. The crystals formed upon cooling were filtered and 27.37 g of the wet cake thus obtained was dried with hot air at 40 ° C. for 24 hours to give 19.41 g of N- (10-camphor-sulfonyloxy) succinimide.

MS: SIMS (FAB), 330 (M + H) ⁺

Example 2

A 200 ml four-necked flask was charged with 17.26 g of N-hydroxysuccinimide, 34.90 g of (+)-10-camphorsulfonyl chloride, and 260.81 g of 1,4-dioxane, and stirred at 25 ° C. for 30 minutes. Then, 15.03 g of triethylamine was added thereto over 30 minutes. After the mixture was stirred for an additional 4 hours, 661.21 g of toluene was added to the reaction and the reaction was washed with 335.61 g of 0.5% aqueous oxalic acid solution. The phases are separated and the organic layer is washed six times with 335.61 g of distilled water and concentrated. 23.39 g of ethyl acetate is added to the concentrate and the mixture is heated to 60 ° C. Next, 79.53 g of n-heptane and 154.37 g of toluene were added and cooled to 25 ° C or lower. The crystals formed are filtered and the resulting wet cake is dried with hot air at 40 ° C. for 24 hours to give 34.52 g of N- (10-camphorsulfonyloxy) succinimide.

Example 3

Propylene glycol monomethyl ether acetate was obtained by the method described in 66 parts (cf. JP-A-5-181279) and 20 mol% of hydroxyl groups in poly (p-vinylphenol) were tert-butoxycarbonyl 13.5 parts of polymer converted to methyl ether, 1.2 parts of N- (10-camphorsulfonyl-oxy) succinimide obtained in Example 1, 0.405 parts of 2-hydroxycarbazole (Aldrich) as an electron donor and propylene 66 parts of glycol monomethyl ether acetate are dissolved and the mixture is passed through a fluorine resin filter having a pore size of 0.2 mu m to obtain a resist solution A.

The resist solution A obtained above is applied using a spin coater onto the cleaned silicon wafer according to a conventional method so that a film having a thickness of 0.7 탆 after drying is formed. The silicon wafer is then pre-baked hot at 100 ° C. for 1 minute. The film after pre-baking was subjected to a KrF excimer laser stepper ["NSR-1755 EX8A", manufacturer having an exposure wavelength length of 248 nm through a chrome mask having a pattern; Nikon, NA = 0.45]. The exposed wafer is post-baked (PEB) on a hot plate at 95 ° C. for 90 seconds. The wafer is then developed with 2.38% aqueous tetramethyl ammonium hydroxide to yield a positive pattern. The positive pattern obtained was evaluated in the following manner and the results are shown in Table 1.

Light Velocity: 0.3 μm line-and-space cross section is observed with a scanning electron microscope and the light velocity (optimized amount of light) is obtained from light exposure which provides 1: 1 line-and-space at optimal focus.

Resolution: The minimum width of the line-and-space division is taken as the resolution without loss of film thickness due to light exposure at the optimized amount of light.

Profile: 0.3 μm line-and-space cross section due to light exposure at the optimized amount of light is observed with a scanning electron microscope.

Small pattern installation: Observe the installation of the resist and evaluate it using a three-level scoring system, where ○ means not installed, △ means partially installed, and X means mostly installed.

In addition, evaluation of all test objects on the baked wafer after standing for 1 hour from exposure is also performed.

Comparative Example 1

Chemical formula 0.405 parts of the compound (manufactured by Midori Kagaku) was applied, except that instead of using N- (10-camphorsulfonyloxy) succinimide used in Example 1, the process of Example 1 was substantially repeated to apply the resist solution B. To obtain. Resist solution B was evaluated in the same manner as in Application Example 1 and the results are shown in Table 1 below.

TABLE 1

* (A) and (b) in the profile means that the shape is Fig. 1a and 1b, respectively.

Example 4

(1) Preparation of N- (10-camphorsulfonyloxy) succinimide

A 2 L four-necked flask is charged with 46.23 g of N-hydroxysuccinimide, 93.45 g of (+)-10-camphorsulfonyl chloride and 698.39 g of acetone. After stirring for 30 minutes at 25 degreeC, 38.41 g of triethylamines are added over 30 minutes. The mixture is stirred for an additional 3 hours and then filtered, and the filtrate is washed with 186.90 g of acetone. To the combined filtrate and washings are added 177.06 g of ethyl acetate and 708.23 g of toluene. The mixture is washed with a solution containing 3.06 g of sodium acetate in 559.06 g of distilled water and the organic layer is further washed with 588.71 g of distilled water. The organic layer is then washed with 588.71 g of 0.5% aqueous oxalic acid solution and washed four more times with 588.71 g of water each. The organic layer was concentrated to give 133.72 g of oily material, to which 334.30 g of toluene was added. The mixture is heated to 50 ° C. to form a homogeneous solution. To this solution was added dropwise stirring a mixed solvent of 133.72 g of toluene and 200.58 g of n-heptane. After addition, the solution is cooled to 25 ° C. over 3 hours, cooled to 5 ° C. and stirred for 1.5 hours. The precipitate formed is filtered and dried overnight at 45 ° C. to give 102.40 g of N- (10-camphorsulfonyloxy) succinimide.

(2) Preparation and Evaluation of Resist

30 moles of hydroxyl groups in poly (p-vinylphenol) obtained by the process described in the literature (cf. JP-A-5-181279) in a mixture of 52 parts of propylene glycol monomethyl ether acetate and 13 parts of ethyl lactate 13.5 parts of polymer in which% was converted to tert-butoxycarbonylmethyl ether, 1.0 part of N- (10-camphorsulfonyloxy) succinimide obtained in (1) above, 2-hydroxycarbox as an electron donor 0.27 parts of bazole and 0.08 parts of N-methyl-2-pyrrolidone are dissolved as a basic compound. The mixture thus obtained is passed through a fluorine resin filter having a pore size of 0.2 mu m to obtain a resist solution.

The resist solution obtained above is coated on a washed silicon wafer according to a conventional method using a spin coater to form a film having a thickness of 0.7 탆 after drying. The silicon wafer is then pre-baked for 90 seconds on a hot plate at 100 ° C. The pre-baked film is irradiated through a chrome mask with a pattern using a KrF excimer laser stepper ("NSR-1755 EX8A", Nikon Ltd.) having an exposure wavelength of 248 nm. The exposed wafer is post-baked (PEB) for 90 seconds on a hot plate at 100 ° C. This wafer is then developed with 2.38% aqueous tetramethyl ammonium hydroxide to yield a positive pattern. The positive pattern obtained is evaluated by the method described in Application Example 1. The light flux is 71 mJ / cm ² when PEB is performed immediately after exposure or 15 minutes after exposure. The resolution is 0.27 μm when PEB is performed immediately after exposure or 15 minutes after exposure. The profile is good as obtained in Application Example 1 when the PEB is performed immediately after exposure or after 15 minutes of exposure.

The N- (10-camphorsulfonyloxy) succinimide obtained in the present invention is an acid for a resist composition comprising an acid generator for a resist composition, particularly an alkali-soluble resin having a protecting group that can be removed by the action of an acid. Useful as a generator. The resist composition using the compound as an acid generator has excellent light speed and resolution, and has a high level of time delay effect and adhesion properties, but also high heat resistance, ratio of residual film thickness after development, uniformity and profile of film thickness, and the like. maintain.

1A is a schematic diagram showing the profile observed in Application Example 1. FIG.

1B is a schematic view showing the profile observed in Comparative Example 1. FIG.

Claims (8)

N- (10-camphorsulfonyloxy) succinimide of formula (1). Formula 1 Process for preparing N- (10-camphorsulfonyloxy) succinimide according to claim 1 comprising reacting N-hydroxysuccinimide with 10-camphorsulfonic acid, salts thereof or halides thereof . The process of claim 2 wherein 10-camphorsulfonyl halide is used and the reaction is carried out in the presence of a basic catalyst. The process according to claim 2 or 3, wherein the reaction is carried out in a polar solvent. The method of claim 2, wherein the reaction product is subjected to a treatment to remove sulfonic acid. 6. The process of claim 5 wherein the treatment for removing sulfonic acid comprises washing the solution comprising the reaction product in a hydrophobic organic solvent with an aqueous solution containing a neutral salt of acid having a lower acidity than sulfonic acid. Way. The process according to claim 2 or 5, wherein the product is crystallized from a halogenated hydrocarbon solvent or a mixed solvent of aliphatic or cycloaliphatic hydrocarbons and aromatic hydrocarbons. A resist composition comprising N- (10-camphorsulfonyloxy) succinimide and an alkali-soluble resin having a protecting group that can be removed by the action of an acid.