JP2009134177A - Pattern forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pattern forming method, capable of suppressing development defects by using a defect removing agent in formation of a fine resist pattern by liquid immersion exposure or the like. <P>SOLUTION: The pattern forming method comprises steps of (1) applying a radiation-sensitive resin composition containing a resin (a) which becomes alkali-soluble by the effect of acid and (b) a radiation-sensitive acid generator (b) onto a substrate to form a coating film followed by exposing; (2) applying a defect removing agent onto the coating film to form a coating layer; and (3) performing development. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pattern forming method. More specifically, the present invention relates to a pattern forming method capable of suppressing development defects by using a defect remover when forming a fine resist pattern by an immersion exposure method or the like.

Stepper-type or step-and-scan projection exposure that transfers a reticle pattern as a photomask to each shot area on a photoresist-coated wafer via a projection optical system when manufacturing semiconductor elements, etc. The device is in use.
The theoretical limit value of the resolution of the projection optical system provided with the projection exposure apparatus becomes higher as the exposure wavelength used is shorter and the numerical aperture of the projection optical system is larger. For this reason, with the miniaturization of integrated circuits, the exposure wavelength, which is the wavelength of radiation used in the projection exposure apparatus, has become shorter year by year, and the numerical aperture of the projection optical system has also increased.
As described above, in the field of manufacturing semiconductor devices, conventionally, the demand for miniaturization of integrated circuits has been met by shortening the exposure wavelength and increasing the numerical aperture. At present, an ArF excimer laser (wavelength 193. Mass production of 1L1S (1: 1 line and space) half pitch 90 nm nodes using 4 nm) is under study. However, it is said that the next-generation half-pitch 65 nm node or 45 nm node, which has been further miniaturized, is difficult to achieve only by using an ArF excimer laser. Therefore, for these next-generation technologies, the use of short-wavelength light sources such as F ₂ excimer laser (wavelength 157 nm), EUV (wavelength 13 nm), etc. is being studied. However, the use of these light sources is technically difficult and is still difficult to use.

In the exposure technique described above, a photoresist film is formed on the surface of the wafer to be exposed, and a pattern is transferred to the photoresist film. In a conventional projection exposure apparatus, a space in which a wafer is placed is filled with air or nitrogen having a refractive index of 1.
However, by filling a liquid having a refractive index n between the lens of the projection exposure apparatus and the wafer and setting an appropriate optical system, the limit value of the resolution and the depth of focus are increased to 1 / n and n times, respectively. It is theoretically possible. For example, in the process of using an ArF excimer laser as the exposure light source, when water is used as the liquid filling the gap between the lens and the wafer, the refractive index n of water having a wavelength of 193.4 nm in water is 1.44. Or, it is theoretically possible to design an optical system in which the resolution is 69.4% and the depth of focus is 144% as compared with the exposure using nitrogen as a medium.
A projection exposure method capable of shortening the effective wavelength of light for exposure and transferring a finer pattern is called immersion exposure. This technology is indispensable for future miniaturization of lithography, especially lithography in the unit of 10 nm. (See, for example, Non-Patent Documents 1 to 3).

Journal of Vacuum Science & Technology B, 1999, Vol. 17, No. 6, 3306-3309 Journal of Vacuum Science & Technology B, 2001, Vol. 19, No. 6, 2353-2356 Proceedings of SPIE, 2002, 4691, 459-465

Development defects (resist components remaining undissolved, etc.) previously washed away by a rinsing process with water or the like during development as the limit resolution dramatically increases and the pattern becomes finer as a result of such technological advances. However, there is a risk that it will remain between patterns, and it is now impossible to ignore.
Therefore, there is a need for a pattern forming method that can easily remove development defects that occur when a fine pattern is formed in a normal exposure method or immersion exposure method.

  The present invention has been made in view of the above circumstances, and can use existing materials and processes, and pattern formation that can suppress development defects by processing with a defect remover after the exposure step. It aims to provide a method.

〔一般式（１−１）〜（１−４）において、Ｒ^１は水素原子、メチル基又はトリフルオロメチル基を示し、Ｒ^２、Ｒ^３及びＲ^４は、それぞれ、単結合、メチレン基、炭素数２〜２０の直鎖状若しくは分岐状のアルキレン基、又は２価の環状炭化水素基を示し、Ｒ^５は少なくとも一つのフッ素原子を含有する炭素数１〜１０の直鎖状若しくは分岐状のアルキル基、又は炭素数３〜１０の脂環式のアルキル基を示し、Ａは単結合、カルボニル基、カルボニルオキシ基、又はオキシカルボニル基を表し、Ｂは単結合、メチレン基、炭素数２〜２０の直鎖状若しくは分岐状のアルキレン基、又は２価の環状炭化水素基を示す。〕
２．前記工程（１）と前記工程（２）の間に、現像により前記塗膜にパターンを付与する現像工程を備える前記１．に記載のパターン形成方法。
３．前記工程（２）と前記工程（３）の間に、加熱処理工程を備える前記２．又は３．に記載のパターン形成方法。 The present invention is as follows.
1. (1) A radiation-sensitive resin composition containing a resin (a) that becomes alkali-soluble by the action of an acid and a radiation-sensitive acid generator (b) is applied on the substrate to form a coating film and exposed. A pattern forming method comprising: a step; (2) a step of applying a defect removing agent on the coating film to form a coating layer; and (3) a developing step, wherein the defect removing agent comprises: The repeating unit represented by the following general formula (1-1), the repeating unit represented by the following general formula (1-2), the repeating unit represented by the following general formula (1-3), and the following general formula ( The pattern formation method characterized by including resin (A) containing at least 1 sort (s) among the repeating units represented by 1-4), and a solvent (B).

[In General Formulas (1-1) to (1-4), R ¹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ² , R ^3, and R ⁴ represent a single bond, a methylene group, A linear or branched alkylene group having 2 to 20 carbon atoms or a divalent cyclic hydrocarbon group, wherein R ⁵ is a linear or branched group having 1 to 10 carbon atoms and containing at least one fluorine atom. Or an alicyclic alkyl group having 3 to 10 carbon atoms, A represents a single bond, a carbonyl group, a carbonyloxy group, or an oxycarbonyl group, and B represents a single bond, a methylene group, or a carbon number of 2 -20 linear or branched alkylene groups, or a bivalent cyclic hydrocarbon group. ]
2. The said 1. provided with the image development process which provides a pattern to the said coating film by image development between the said process (1) and the said process (2). The pattern forming method according to 1.
3. 2. The heat treatment step is provided between the step (2) and the step (3). Or 3. The pattern forming method according to 1.

  According to the pattern formation method of the present invention, after the exposure step, the development defect is removed by treating the coating film to which the pattern is applied or the coating film to which the pattern is not applied with a defect removing agent. Occurrence can be suppressed. In addition, after providing a pattern to the coating film, a coating layer is formed on the coating film using a defect remover, and when this coating layer is developed, a development defect (resist component residue) generated on the pattern Etc.) react with the acidic functional group in the resin component in the coating layer, and the development defects are easily dissolved in the developer. Therefore, when the coating layer is developed and removed, the development defects are also removed at the same time. Conceivable. On the other hand, when a coating layer is formed using a defect remover on a coating film formed using a radiation-sensitive resin composition before the pattern is provided by development, and the coating film and the coating layer are developed. Since the surface side of the coating film reacts with the acidic functional group in the resin component in the coating layer and the solubility in the developer is further improved, it is considered that development defects after development are suppressed.

  Hereinafter, the present invention will be described in detail. In the present specification, “(meth) acryl” means acryl and methacryl, and “(meth) acrylate” means acrylate and methacrylate.

[1] Pattern Forming Method The pattern forming method of the present invention comprises: (1) a radiation sensitive resin comprising a resin (a) that becomes alkali-soluble by the action of an acid and a radiation sensitive acid generator (b) on a substrate. A step of applying a composition to form a coating film, and exposing (hereinafter referred to as “step (1)”); and (2) forming a coating layer by applying a defect removing agent on the coating film. A step (hereinafter referred to as “step (2)”), and (3) a step of developing (hereinafter referred to as “step (3)”).

<Process (1)>
In the step (1), after a coating film (photoresist film) is formed on the substrate by applying the radiation-sensitive resin composition, a predetermined pattern is formed in a desired region of the formed photoresist film. Exposure is performed by irradiating radiation through a mask. The “radiation sensitive resin composition” will be described in detail later.

Examples of the substrate include a silicon wafer and a wafer coated with aluminum. An organic or inorganic antireflection film may be formed on the substrate to be used in order to maximize the potential of the radiation sensitive resin composition.
Examples of means for applying the radiation-sensitive resin composition on the substrate include appropriate application means such as spin coating, cast coating, and roll coating.

Moreover, in the said process (1), after apply | coating a radiation sensitive resin composition, the solvent in a coating film may be volatilized by prebaking (PB) as needed, and a photoresist film may be formed. . The prebaking heating conditions are appropriately selected depending on the composition of the radiation sensitive resin composition, but the heating temperature is usually about 30 to 200 ° C, preferably 50 to 150 ° C. The heating time is usually 10 to 300 seconds, preferably 30 to 180 seconds.
The thickness of the formed photoresist film is not particularly limited, but is usually 10 to 1000 nm, preferably 10 to 500 nm. Further, an immersion protective film may be formed on the photoresist film in order to prevent elution and dissolution of photoresist film components such as an acid generator during exposure.

The radiation used for the exposure is appropriately selected from visible rays, ultraviolet rays, far ultraviolet rays, X-rays, charged particle beams, etc., depending on the type of acid generator and the like contained in the radiation-sensitive resin composition. . Among these, far ultraviolet rays represented by ArF excimer laser (wavelength 193 nm) or KrF excimer laser (wavelength 248 nm) are preferable.
Moreover, exposure conditions, such as exposure amount, are suitably selected according to the compounding composition of a radiation sensitive resin composition.

In addition, after the exposure, the exposed coating film may be cleaned by using a cleaning liquid such as an organic solvent containing at least one selected from alkyl alcohols, alkyl ethers, and hydrocarbons. Specifically, for example, by placing the cleaning liquid on the coating film subjected to the immersion exposure process and rotating the substrate, the residual immersion liquid is removed together with the cleaning liquid by spin-off, and then the rotation is continued. Examples include a method of drying the substrate.
The cleaning time is not particularly limited as long as the immersion liquid can be removed from the surface of the photoresist film, but is usually 1 to 300 seconds, preferably 5 to 200 seconds, and more preferably 5 to 150 seconds.

  Furthermore, it is preferable to perform heat treatment (PEB) after the exposure. By this heat treatment, the dissociation reaction of the acid dissociable group in the resin component can smoothly proceed. The heating conditions are appropriately selected depending on the composition of the radiation sensitive resin composition, but the heating temperature is usually 30 to 200 ° C, preferably 50 to 170 ° C. The heating time is usually 10 to 300 seconds, preferably 30 to 180 seconds.

Moreover, the pattern formation method of this invention may be equipped with the image development process which provides a pattern to the said coating film by image development between the said process (1) and the below-mentioned process (2).
When this development step is provided, a predetermined pattern is imparted to the photoresist film by developing the exposed portion exposed in the step (1) using a developer.

Examples of the developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyl Diethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- [4.3 0.0] -5-nonene and an alkaline aqueous solution in which at least one kind of alkaline compound is dissolved.
In addition, it is preferable that the density | concentration of alkaline aqueous solution is 10 mass% or less. When the concentration of the alkaline aqueous solution exceeds 10% by mass, there is a possibility that the region other than the predetermined region may be dissolved in the developer.

An organic solvent can also be added to the developer composed of the alkaline aqueous solution.
Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone, methyl i-butyl ketone, cyclopentanone, cyclohexanone, 3-methylcyclopentanone, and 2,6-dimethylcyclohexanone; methyl alcohol, ethyl alcohol, and n-propyl. Alcohols such as alcohol, i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclopentanol, cyclohexanol, 1,4-hexanediol, 1,4-hexanedimethylol; ethers such as tetrahydrofuran and dioxane Esters such as ethyl acetate, n-butyl acetate and i-amyl acetate; aromatic hydrocarbons such as toluene and xylene; phenol, acetonylacetone and dimethylformamide. These organic solvents may be used individually by 1 type, and may be used in combination of 2 or more type.
In addition, the usage-amount of an organic solvent has preferable 100 volume% or less with respect to alkaline aqueous solution. When the amount of the organic solvent used exceeds 100% by volume, the developability is lowered, and there is a possibility that the development residue in the exposed area increases.

An appropriate amount of a surfactant or the like can be added to the developer composed of the alkaline aqueous solution.
In addition, after developing with a developing solution, generally the process of carrying out the rinse washing | cleaning using water etc., and drying is provided.

<Process (2)>
In the step (2), a coating layer is formed by applying a defect removing agent on the coating film. The “defect removing agent” will be described in detail later.
Examples of the means for applying the defect removing agent onto the coating film include appropriate application means such as spin coating, cast coating, and roll coating.

  Although the thickness of the said coating layer is not specifically limited, Usually, it is 1-1000 nm, Preferably it is 10-100 nm.

Moreover, it is preferable that the pattern formation method of this invention is equipped with the heat processing process between the said process (2) and the below-mentioned process (3) from a viewpoint that the effect of a defect removal agent can be amplified more. In the present invention, by providing this heat treatment step, the interface between the coating film provided with the pattern or the coating film before the pattern is applied and the coating layer formed using the defect remover is sufficiently reacted. Since the solubility in the developing solution can be further improved, it is considered that the effect of the defect removing agent can be further amplified.
The heating conditions in the heat treatment step are appropriately selected depending on the composition of the radiation sensitive resin composition and the like, but are usually 30 to 200 ° C, preferably 50 to 170 ° C.

<Process (3)>
In the step (3), development is performed by using a developer.
At this time, when a pattern is imparted to the coated film after exposure, the coating layer is removed by the developer to form a resist pattern. In this case, with the removal of the coating layer, it is possible to remove development defect portions such as undissolved defects on the coating film provided with a pattern.
On the other hand, when the pattern is not given to the coating film after exposure, the coating layer is removed by the developer and a predetermined region of the coating film is developed to form a resist pattern. In this case, it is possible to sufficiently suppress development defect portions such as unmelted defects.

  The above description can be applied to the developer as it is. The developer used in this step (3) and the developer used in the developing step between the steps (1) and (2) may be the same or different.

  In addition, after the development in the step (3), a step of rinsing with water or the like and then drying is generally provided.

  Moreover, in the pattern formation method of this invention, in order to improve the removal rate of a development defect, you may repeat the said process (2) and process (3) twice or more. That is, once the coating layer is removed, a coating layer is formed again using a defect remover on the pattern obtained, and after heat treatment as necessary, the coating layer is removed with a developer. Thus, a pattern can be formed.

[2] Defect Remover The defect remover used in the step (2) in the pattern forming method of the present invention is a repeating unit represented by the following general formula (1-1) [hereinafter, “repeating unit (1-1 ) ". ], A repeating unit represented by the following general formula (1-2) [hereinafter also referred to as “repeating unit (1-2)”. ], A repeating unit represented by the following general formula (1-3) [hereinafter also referred to as “repeating unit (1-3)”. And a repeating unit represented by the following general formula (1-4) [hereinafter also referred to as “repeating unit (1-4)”. ] A resin (A) containing at least one repeating unit having an acidic functional group selected from the above and a solvent (B).

〔一般式（１−１）〜（１−４）において、Ｒ^１は水素原子、メチル基又はトリフルオロメチル基を示し、Ｒ^２、Ｒ^３及びＲ^４は、それぞれ、単結合、メチレン基、炭素数２〜２０の直鎖状若しくは分岐状のアルキレン基、又は２価の環状炭化水素基を示し、Ｒ^５は少なくとも一つのフッ素原子を含有する炭素数１〜１０の直鎖状若しくは分岐状のアルキル基、又は炭素数３〜１０の脂環式のアルキル基を示し、Ａは単結合、カルボニル基、カルボニルオキシ基、又はオキシカルボニル基を表し、Ｂは単結合、メチレン基、炭素数２〜２０の直鎖状若しくは分岐状のアルキレン基、又は２価の環状炭化水素基を示す。〕

[In General Formulas (1-1) to (1-4), R ¹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ² , R ^3, and R ⁴ represent a single bond, a methylene group, A linear or branched alkylene group having 2 to 20 carbon atoms or a divalent cyclic hydrocarbon group, wherein R ⁵ is a linear or branched group having 1 to 10 carbon atoms and containing at least one fluorine atom. Or an alicyclic alkyl group having 3 to 10 carbon atoms, A represents a single bond, a carbonyl group, a carbonyloxy group, or an oxycarbonyl group, and B represents a single bond, a methylene group, or a carbon number of 2 -20 linear or branched alkylene groups, or a bivalent cyclic hydrocarbon group. ]

R ^{2 to} R ⁴ in the general formulas (1-1) to (1-3) are each a single bond, a methylene group, a linear or branched alkylene group having 2 to 20 carbon atoms, or a divalent group. A cyclic hydrocarbon group, and among these, a linear or branched alkylene group having 2 to 20 carbon atoms, a divalent cyclic hydrocarbon group, an alkylene glycol group, or an alkylene ester group is preferable. R ² , R ³ and R ⁴ may be the same or different.

Specific examples of R ^{2 to} R ⁴ in the general formulas (1-1) to (1-3) include a methylene group, an ethylene group, a 1,2-propylene group, a 1,3-propylene group, and a tetramethylene group. Group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, tridecamethylene group, tetradecamethylene group, pentadecamethylene group, hexadeca Methylene group, heptacamethylene group, octadecamethylene group, nonadecamethylene group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group, 2-methyl-1,4-butylene group, methylidene group, ethylidene group, propylidene group, 2 Saturated chain hydrocarbon group such as propylidene group; cyclobutylene group such as 1,3-cyclobutylene group; cyclopentylene group such as 1,3-cyclopentylene group; cyclohexylene such as 1,4-cyclohexylene group Group; monocyclic hydrocarbon ring group; norbornylene group; bridged cyclic hydrocarbon ring group and the like.

Examples of the monocyclic hydrocarbon ring group include a cycloalkylene group having 3 to 10 carbon atoms. Specific examples of the cycloalkylene group include a cyclooctylene group such as a 1,5-cyclooctylene group.
Examples of the norbornylene group include a 1,4-norbornylene group and a 2,5-norbornylene group.
Furthermore, examples of the bridged cyclic hydrocarbon ring group include 2 to 4 cyclic hydrocarbon ring groups having 4 to 30 carbon atoms. Specific examples of the 2-4 cyclic hydrocarbon ring group having 4 to 30 carbon atoms include adamantylene groups such as 1,5-adamantylene group and 2,6-adamantylene group.

Further, the divalent organic group in R ² of the general formula (1-1) may be one in which the above-described functional group is bonded. For example, when the divalent organic group has a monocyclic hydrocarbon ring group or a bridged cyclic hydrocarbon ring group in its structure, it is represented by the general formula (1-1) at the end of the group. As a spacer between the bistrifluoromethyl-hydroxymethyl group in the repeating unit to be formed, a structure in which a linear alkylene group having 1 to 4 carbon atoms is bonded is preferable.

In particular, R ² in the general formula (1-1) is preferably a hydrocarbon group containing a 2,5-norbornylene group, a 1,2-ethylene group, or a propylene group.

As a preferable monomer (radically polymerizable monomer) which gives the repeating unit (1-1), for example, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2- Hydroxy-3-propyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-butyl) ester, (meth) acrylic acid (1,1,1) -Trifluoro-2-trifluoromethyl-2-hydroxy-5-pentyl) ester, (meth) acrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-pentyl) ester , (Meth) acrylic acid 2-{[5- (1 ′, 1 ′, 1′-trifluoro-2′-trifluoromethyl-2′-hydroxy) propyl] bicyclo [2.2.1] hept Ester}, (meth) acrylic acid 3-{[8- (1 ′, 1 ′, 1′-trifluoro-2′-trifluoromethyl-2′-hydroxy) propyl] tetracyclo [6.2.1. 1 ^3,6 . 0 ^2,7 ] dodecyl} ester and the like. In addition, these monomers may be used individually by 1 type, and may be used in combination of 2 or more type.

Moreover, as a preferable monomer (radical polymerizable monomer) which gives the repeating unit (1-2), for example, (meth) acrylic acid, bicyclo [2.2.1] hept-5-ene-2 -Ylmethanecarboxylic acid, 2-bicyclo [2.2.1] hept-5-enecarboxylic acid, 4-tricyclo [5.2.1.0 ^2,6 ] dec-8-enecarboxylic acid, tricyclo [5 .2.1.0 ^2,6 ] dec-8-en-4-ylmethanecarboxylic acid, bicyclo [2.2.1] hept-5-en-2-ylmethanecarboxylic acid and the like. These monomers may be used individually by 1 type, and may be used in combination of 2 or more type.

R ⁵ in the general formula (1-3) is a linear or branched alkyl group having 1 to 10 carbon atoms or an alicyclic alkyl group having 3 to 10 carbon atoms containing at least one fluorine atom. In particular, a trifluoromethyl group is preferable.

  Moreover, as a preferable monomer (radical polymerizable monomer) which gives the repeating unit (1-3), for example, [[(trifluoromethyl) sulfonyl] amino] ethyl-1-methacrylate, 2-[[ (Trifluoromethyl) sulfonyl] amino] ethyl-1-acrylate, compounds represented by the following formulas, and the like. These monomers may be used individually by 1 type, and may be used in combination of 2 or more type.

A in the general formula (1-4) is a single bond, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.
B in the general formula (1-4) represents a single bond, a methylene group, a linear or branched alkylene group having 2 to 20 carbon atoms, or a divalent cyclic hydrocarbon group.

  Specific examples of B in the general formula (1-4) include, for example, a methylene group, an ethylene group, a 1,2-propylene group, a 1,3-propylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, Heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, tridecamethylene group, tetradecamethylene group, pentadecamethylene group, hexadecamethylene group, heptacamethylene group, octadecamethan group Methylene group, nonadecamethylene group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group 2-methyl-1,4-butylene group, methylidene group, ethylidene group, propylidene group, 2-propylidene group, etc. Chain hydrocarbon group; cyclobutylene group such as 1,3-cyclobutylene group; cyclopentylene group such as 1,3-cyclopentylene group; cyclohexylene group such as 1,4-cyclohexylene group; monocyclic Hydrocarbon ring group; norbornylene group; bridged cyclic hydrocarbon ring group and the like.

Examples of the monocyclic hydrocarbon ring group include a cycloalkylene group having 3 to 10 carbon atoms. Specific examples of the cycloalkylene group include a cyclooctylene group such as a 1,5-cyclooctylene group.
Examples of the norbornylene group include a 1,4-norbornylene group and a 2,5-norbornylene group.
Furthermore, examples of the bridged cyclic hydrocarbon ring group include 2 to 4 cyclic hydrocarbon ring groups having 4 to 30 carbon atoms. Specific examples of the 2-4 cyclic hydrocarbon ring group having 4 to 30 carbon atoms include adamantylene groups such as 1,5-adamantylene group and 2,6-adamantylene group.

  Moreover, as a preferable monomer (radical polymerizable monomer) which gives the repeating unit (1-4), for example, vinyl sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methyl-1- Examples include propanesulfonic acid and 4-vinyl-1-benzenesulfonic acid. Among these sulfonic acid monomers, these monomers including vinyl sulfonic acid and allyl sulfonic acid may be used alone or in combination of two or more.

  The resin (A) preferably contains at least the repeating unit (1-4) among the repeating units (1-1) to (1-4). In the case of containing this repeating unit (1-4), alkali solubility can be imparted to a component that forms an undissolved defect due to insufficient alkali solubility.

The resin (A) includes other repeating units other than the repeating units (1-1) to (1-4) for the purpose of controlling the molecular weight, glass transition point, solubility in a solvent, and the like of the resin. May be contained.
Examples of the monomer that gives the other repeating unit include radical polymerizable monomers other than the above-mentioned radical polymerizable monomers, acid dissociable group-containing monomers, and the like. Specifically, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, isopropyl (meth) acrylate, n -Hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-methylcyclohexyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, methoxydi Propylene glycol (meth) acrylate, butoxy-dipropylene glycol (meth) acrylate, methoxydiethylene glycol (meth) acrylate, methoxypropylene glycol (meth) acrylate, 2 Methyl-2-adamantyl (meth) acrylate, 2-ethyl-2-adamantyl (meth) acrylate, 2-propyl-2-adamantyl (meth) acrylate, 2-butyl-2-adamantyl (meth) acrylate, 1-methyl- 1-cyclohexyl (meth) acrylate, 1-ethyl-1-cyclohexyl (meth) acrylate, 1-propyl-1-cyclohexyl (meth) acrylate, 1-butyl-1-cyclohexyl (meth) acrylate, 1-methyl-1- Cyclopentyl (meth) acrylate, 1-ethyl-1-cyclopentyl (meth) acrylate, 1-propyl-1-cyclopentyl (meth) acrylate, 1-butyl-1-cyclopentyl (meth) acrylate, 1-adamantyl-1-methylethyl (Meta) ak Rate, (meth) acrylic acid alkyl esters such as 1-bicyclo [2.2.1] heptyl-1-methylethyl (meth) acrylate; dicarboxylic acid diesters such as diethyl maleate, diethyl fumarate and diethyl itaconate; phenyl (Meth) acrylic acid aryl esters such as (meth) acrylate and benzyl (meth) acrylate; aromatic vinyl such as styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, p-methoxystyrene Nitrile group-containing radical polymerizable monomers such as acrylonitrile and methacrylonitrile; amide bond-containing radical polymerizable monomers such as acrylamide and methacrylamide; fatty acid vinyls such as vinyl acetate; vinyl chloride, vinylidene chloride, etc. Chlorine-containing radical polymerizable monomer 1,3-butadiene, isoprene, 1,4-dimethyl butadiene conjugated diolefins such as and the like. Of these, (meth) acrylic acid alkyl esters, nitrile group-containing radical polymerizable monomers, amide bond-containing radical polymerizable monomers, and hydroxyl group-containing (meth) acrylic acid alkyl esters are preferred. In addition, these monomers may be used individually by 1 type, and may be used in combination of 2 or more type.

  The content of the other repeating units is preferably 50 mol% or less, more preferably 40 mol% or less, when the entire repeating unit contained in the resin (A) is 100 mol%. When the content ratio of other repeating units exceeds 50 mol%, the solubility in an alkaline aqueous solution as a developer is lowered, and the coating film formed using a defect remover cannot be removed. The residue may be generated on the resist pattern.

  In addition, the resin (A) includes, for example, a polymerizable unsaturated monomer for constituting each of the above-described repeating units, radicals such as hydroperoxides, dialkyl peroxides, diacyl peroxides, and azo compounds. It can be prepared by polymerizing in a suitable solvent using a polymerization initiator and optionally in the presence of a chain transfer agent.

  Examples of the polymerization solvent used in producing the resin (A) include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, ethylene glycol, diethylene glycol, and propylene glycol. Cyclic ethers such as tetrahydrofuran and dioxane; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether , Propylene glycol monomethyl a And alkyl ethers of polyhydric alcohols such as propylene glycol monoethyl ether; alkyl ether acetates of polyhydric alcohols such as ethylene glycol ethyl ether acetate, diethylene glycol ethyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol monomethyl ether acetate; Aromatic hydrocarbons such as toluene and xylene; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, diacetone alcohol; ethyl acetate, butyl acetate, 2-hydroxy Methyl propionate, ethyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethoxy And esters such as ethyl acid, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate It is done. Of these, cyclic ethers, polyhydric alcohol alkyl ethers, polyhydric alcohol alkyl ether acetates, ketones, and esters are preferred.

The weight average molecular weight (hereinafter also referred to as “Mw”) of the resin (A) is usually 2000 to 100000, preferably 2500 to 50000, more preferably 3000 to 20000 in terms of gel permeation chromatography polystyrene. . When Mw of this resin (A) is less than 2000, there is a possibility that a uniform coating layer cannot be formed with a defect remover. On the other hand, when exceeding 100,000, there exists a possibility that sufficient solubility with respect to the below-mentioned solvent (B) may not be obtained.
The ratio (Mw / Mn) of Mw of the resin (A) to polystyrene-reduced number average molecular weight (hereinafter also referred to as “Mn”) by gel permeation chromatography (GPC) is usually 1 to 5, preferably 1. ~ 3.

The resin (A) is preferably as less as possible as impurities such as halogen and metal. Thereby, the coating property and the uniform solubility in an alkali developer can be further improved.
Examples of resin purification methods include chemical purification methods such as washing with water and liquid-liquid extraction, and combinations of these chemical purification methods with physical purification methods such as ultrafiltration and centrifugation. Can do.
In addition, the defect removal agent in this invention may contain only 1 type of the said resin (A), and may contain 2 or more types.

  The solvent (B) is not particularly limited as long as it does not dissolve the photoresist film. Examples of the solvent include water, alkyl alcohols, alkyl ethers, hydrocarbons and the like.

  Examples of the alkyl alcohols include 1-propanol, n-butanol, 2-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-propanol, neopentyl alcohol, tert- Amyl alcohol, isoamyl alcohol, 3-methyl-2-butanol, 2-methyl-1-butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 4-methyl-2-pentanol and the like It is done. Among these, n-butanol, 2-butanol, 4-methyl-2-pentanol and the like are preferable.

  Examples of the alkyl ethers include dipropyl ether, diisopropyl ether, butyl methyl ether, butyl ethyl ether, butyl propyl ether, dibutyl ether, diisobutyl ether, tert-butyl methyl ether, tert-butyl ethyl ether, tert-butyl. Propyl ether, di-tert-butyl ether, dipentyl ether, diisoamyl ether, cyclopentyl methyl ether, cyclohexyl methyl ether, cyclopentyl ethyl ether, cyclohexyl ethyl ether, cyclopentyl propyl ether, cyclopentyl-2-propyl ether, cyclohexyl propyl ether, cyclohexyl-2 -Propyl ether, cyclopentyl butyl ether, cyclopentyl -tert- butyl ether, cyclohexyl ether, cyclohexyl -tert- butyl ether and the like. Furthermore, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether, propylene Examples include alkyl ethers of polyhydric alcohols such as glycol monoethyl ether. Among these, dibutyl ether, diisobutyl ether, di-tert-butyl ether, dipentyl ether, diisoamyl ether and the like are preferable.

Examples of the hydrocarbons include higher hydrocarbons such as decane, dodecane, and undecane; and aromatic hydrocarbons such as benzene, toluene, and xylene. Of these, decane, toluene and the like are preferable.
In addition, these solvent (B) may be used individually by 1 type, and may mix and use 2 or more types.

  When the solvent (B) is an organic solvent containing at least one selected from alkyl alcohols, alkyl ethers and hydrocarbons, when the total amount of the organic solvent is 100% by mass, the alkyl alcohols The total content of alkyl ethers and hydrocarbons is preferably 30 to 100% by mass, more preferably 50 to 100% by mass, and still more preferably 60 to 100% by mass. When the content is 50 to 100% by mass, the photoresist film is not damaged.

Further, the defect remover can contain a low molecular compound for the purpose of improving the solubility of the resulting coating layer in a developer.
Examples of the low molecular weight compound include a compound containing an acidic functional group represented by the following general formula (2). In addition, this low molecular weight compound may be used individually by 1 type, and may mix and use 2 or more types.

〔一般式（２）において、Ｒ^６は、互いに独立に、炭素数１〜１０の直鎖状或いは分岐状のアルキル基、炭素数３〜１０の脂環式アルキル基若しくはその誘導体、ヒドロキシル基、カルボキシル基、アルキルエーテル基、アルキルオキシカルボニル基、アルキルカルボニルオキシ基を示し、Ｚは炭素数４〜１２の直鎖状、分岐状若しくは脂環式の炭化水素基又は置換基を有してよい芳香族炭化水素基を示し、ｍは０〜４の整数であり、ｎは１〜４の整数である。〕

[In General Formula (2), R ⁶ is independently of each other a linear or branched alkyl group having 1 to 10 carbon atoms, an alicyclic alkyl group having 3 to 10 carbon atoms or a derivative thereof, a hydroxyl group, A carboxyl group, an alkyl ether group, an alkyloxycarbonyl group, an alkylcarbonyloxy group, and Z represents a straight-chain, branched or alicyclic hydrocarbon group having 4 to 12 carbon atoms or an aromatic group which may have a substituent. A group hydrocarbon group is shown, m is an integer of 0-4, n is an integer of 1-4. ]

  Specific compounds represented by the general formula (2) include, for example, benzenesulfonic acid, 2-hydroxybenzenesulfonic acid, 3-hydroxybenzenesulfonic acid, 3-sulfosalicylic acid, 4-sulfosalicylic acid, and 5-sulfosalicylic acid. 1-naphthylsulfonic acid, 2-naphthylsulfonic acid, cyclohexylsulfonic acid, 2-hydroxycyclohexylsulfonic acid, 3-hydroxycyclohexylsulfonic acid and the like.

  Further, the defect removing agent may contain an additive such as a surfactant within a range not impairing the effects of the present invention.

  As the defect removing agent, the resin (A) and the like are contained in the solvent (B), for example, at a solid content concentration of 0.01 to 1% by mass (preferably 0.01 to 0.5% by mass). For example, it is preferable to use a solution prepared by filtering with a filter having a pore size of about 0.2 μm after being dissolved.

[3] Radiation-sensitive resin composition The radiation-sensitive resin composition used in the step (1) in the pattern forming method of the present invention is a resin (a) [hereinafter referred to simply as “resin” that becomes alkali-soluble by the action of an acid. (A) ". ] And a radiation sensitive acid generator (b) [hereinafter also simply referred to as “acid generator (b)”. A chemically amplified positive or negative radiation sensitive resin composition.

  The resin (a) is an alkali-insoluble or hardly alkali-soluble resin that becomes alkali-soluble by the action of an acid. Incidentally, the term “alkali insoluble or alkali insoluble” as used herein refers to an alkali developing condition employed when a resist pattern is formed from a photoresist film formed from a resin composition containing the resin (a). When a film using only the resin (a) instead of the photoresist film is developed, it means that 50% or more of the initial film thickness of the film remains after development.

The resin (a) is a repeating unit having a lactone skeleton in the main chain or side chain [hereinafter referred to as “lactone skeleton-containing repeating unit”. ] Is preferable.
Examples of this lactone skeleton-containing repeating unit include repeating units having groups (side chains) such as the following general formulas (L-1) to (L-6). The main chain skeleton of the lactone skeleton-containing repeating unit is not particularly limited, but preferably has a structure such as methacrylic acid ester, acrylic acid ester, or α-trifluoroacrylic acid ester.

〔一般式（Ｌ−１）〜（Ｌ−６）の各式において、Ｒ^７は水素原子又は炭素数１〜４の置換若しくは非置換のアルキル基を示し、Ｒ^８は水素原子又はメトキシ基を示す。Ａは単結合又はメチレン基を示し、Ｂは酸素原子又はメチレン基を示す。ｌは１〜３の整数を示し、ｍは０又は１である。〕

[In the formulas (L-1) to (L-6), R ⁷ represents a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, and R ⁸ represents a hydrogen atom or a methoxy group. Show. A represents a single bond or a methylene group, and B represents an oxygen atom or a methylene group. l represents an integer of 1 to 3, and m is 0 or 1. ]

Examples of the substituted or unsubstituted alkyl group having 1 to 4 carbon atoms in R ⁷ of the general formula (L-1) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and an n-butyl group. Group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group and the like.

  In the resin (a), only one type of the lactone skeleton-containing repeating unit may be contained, or two or more types may be contained.

  The resin (a) is a repeating unit represented by the following general formula (3) [hereinafter referred to as “repeating unit (3)”. ] Is further preferably contained.

〔一般式（３）において、Ｒ^９は水素原子、メチル基又はトリフルオロメチル基を示す。Ｒ^１０は相互に独立に炭素数４〜２０の１価の脂環式炭化水素基若しくはその誘導体、又は炭素数１〜４の直鎖状若しくは分岐状のアルキル基を示す。尚、いずれか２つのＲ^１０が相互に結合して、それぞれが結合している炭素原子と共に炭素数４〜２０の２価の脂環式炭化水素基若しくはその誘導体を形成していてもよい。〕

[In General Formula (3), R ⁹ represents a hydrogen atom, a methyl group or a trifluoromethyl group. R ¹⁰ independently represents a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or a linear or branched alkyl group having 1 to 4 carbon atoms. Any two of R ¹⁰ may be bonded to each other to form a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof together with the carbon atoms to which they are bonded. ]

  The resin (a) may contain only one type of the repeating unit (3), or may contain two or more types.

  In addition to the lactone skeleton-containing repeating unit and the repeating unit (3), the resin (a) may contain one or more other repeating units.

The content ratio of the lactone skeleton-containing repeating unit in the resin (a) is preferably 10 to 70 mol% when the total of all repeating units contained in the resin (a) is 100 mol%, More preferably, it is 15-65 mol%, More preferably, it is 20-60 mol%. When the content of the lactone skeleton-containing repeating unit is less than 10 mol%, the resist may have poor solubility in an alkaline developer, which may contribute to development defects or deteriorate the exposure margin. The “exposure margin” indicates a variation in line width with respect to a change in exposure amount. On the other hand, when the content exceeds 70 mol%, the solubility of the resist in the solvent is lowered, and the resolution may be lowered.
The content of the repeating unit (3) is preferably 10 to 90 mol%, more preferably 10 when the total of all repeating units contained in the resin (a) is 100 mol%. It is -80 mol%, More preferably, it is 20-70 mol%. When the content ratio of the repeating unit (3) is less than 10 mol%, the resolution as a resist may be deteriorated. On the other hand, if the content ratio exceeds 90 mol%, the developability of the resist may be deteriorated.
Furthermore, the content of the other repeating units is preferably 60 mol% or less, more preferably 50 mol%, when the total of all repeating units contained in the resin (a) is 100 mol%. Hereinafter, it is more preferably 40 mol% or less.

  In addition, the resin (a) is, for example, a polymerizable unsaturated monomer for constituting each repeating unit described above, radicals such as hydroperoxides, dialkyl peroxides, diacyl peroxides, and azo compounds. It can be prepared by polymerizing in a suitable solvent using a polymerization initiator and optionally in the presence of a chain transfer agent.

The molecular weight of the resin (a) is not particularly limited, but the polystyrene-equivalent weight average molecular weight (hereinafter also referred to as “Mw”) by gel permeation chromatography (GPC) is preferably 1000 to 100,000, more preferably. It is 1000-30000, More preferably, it is 1000-20000. When the Mw of the resin (a) is less than 1000, when the photoresist film is formed, the heat resistance may be lowered. On the other hand, if the Mw exceeds 100,000, the developability may be lowered when a photoresist film is formed.
The ratio (Mw / Mn) of Mw of the resin (a) to polystyrene-reduced number average molecular weight (hereinafter also referred to as “Mn”) by gel permeation chromatography (GPC) is usually 1 to 5, preferably Is 1-3.

  The resin (a) may contain a low molecular weight component derived from a monomer used when preparing the resin. The content of the low molecular weight component is preferably 0.1% by mass or less, more preferably 0.07% by mass or less, further preferably 100% by mass (in terms of solid content) of the resin (a). It is 0.05 mass% or less. When this content is 0.1% by mass or less, no foreign matter is generated in the composition during storage of the radiation-sensitive resin composition, and coating unevenness does not occur during coating of the composition. It is possible to sufficiently suppress the occurrence of defects when forming a resist pattern. Furthermore, it is possible to reduce the amount of eluate in the immersion liquid that comes into contact during immersion exposure.

  The low molecular weight component may be a component having an Mw of 500 or less, and specifically includes a monomer, a dimer, a trimer, and an oligomer. This low molecular weight component (component of Mw 500 or less) is, for example, a chemical purification method such as washing with water or liquid-liquid extraction, or a combination of these chemical purification methods and a physical purification method such as ultrafiltration or centrifugation. Can be removed. The analysis can be performed by high performance liquid chromatography (HPLC).

Further, the resin (a) is preferably one having few impurities such as halogen and metal. By reducing such impurities, the sensitivity, resolution, process stability, pattern shape of the photoresist film to be formed are reduced. Etc. can be further improved.
Examples of the purification method of the resin (a) include chemical purification methods such as washing with water and liquid-liquid extraction, and combinations of these chemical purification methods with physical purification methods such as ultrafiltration and centrifugation. Can be mentioned.

  In addition, the radiation sensitive resin composition in this invention may contain only 1 type of the said resin (a), and may contain 2 or more types.

  The acid generator (b) generates an acid upon exposure and functions as a photoacid generator. This acid generator (b) dissociates the acid-dissociable group present in the resin (a) contained in the radiation-sensitive resin composition by the acid generated by exposure (releases the protecting group). The resin (a) is alkali-soluble. As a result, the exposed portion of the resist film becomes readily soluble in an alkaline developer, thereby forming a positive resist pattern.

  As said acid generator (b), what contains the compound represented by following General formula (4) is preferable.

In the general formula (4), R ¹¹ is a hydrogen atom, a fluorine atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, a linear or branched alkoxyl group having 1 to 10 carbon atoms, A linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms is shown.
R ¹² represents a linear or branched alkyl group having 1 to 10 carbon atoms, an alkoxyl group, or a linear, branched or cyclic alkanesulfonyl group having 1 to 10 carbon atoms.
Further, R ¹³ independently represents a linear or branched alkyl group having 1 to 10 carbon atoms, an optionally substituted phenyl group or an optionally substituted naphthyl group, or two R ¹³ represents a divalent group having 2 to 10 carbon atoms that may be bonded to each other. k is an integer of 0 to 2, and r is an integer of 0 to 10. X ⁻ represents a formula: RC _n F _2n SO ₃ ⁻ , RSO ₃ ⁻ (wherein R represents a hydrogen atom, a fluorine atom, or an optionally substituted hydrocarbon group having 1 to 12 carbon atoms. , N is an integer of 1 to 10), and represents an anion represented by the following general formula (5-1) or (5-2).

〔前記一般式（５−１）及び（５−２）において、Ｒ^１４は独立にフッ素原子を含有する炭素数１〜１０の直鎖状若しくは分岐状のアルキル基を示すか、或いは、２個のＲ^１４が互いに結合し、フッ素原子を含有しており且つ置換基を有していてもよい炭素数２〜１０の２価の基を示す。Ｒ^１５は独立にフッ素原子を含有する炭素数１〜１０の直鎖状若しくは分岐状のアルキル基を示す。尚、いずれか２個のＲ^１５が互いに結合し、フッ素原子を含有しており且つ置換基を有していてもよい炭素数２〜１０の２価の基を形成していてもよい。〕

[In the general formulas (5-1) and (5-2), R ¹⁴ independently represents a linear or branched alkyl group having 1 to 10 carbon atoms containing a fluorine atom, or 2 R ^{14 in the} formula (1) represents a divalent group having 2 to 10 carbon atoms which is bonded to each other and contains a fluorine atom and may have a substituent. R ¹⁵ independently represents a linear or branched alkyl group having 1 to 10 carbon atoms containing a fluorine atom. In addition, any two R ¹⁵ may be bonded to each other to form a divalent group having 2 to 10 carbon atoms which contains a fluorine atom and may have a substituent. ]

  In addition, the said acid generator (b) may be used individually by 1 type, and may be used in combination of 2 or more type.

  The compounding amount of the acid generator (b) is 100 parts by weight of the resin (a) from the viewpoint of sensitivity and developability as a resist and suppression of elution from the resist film to the immersion liquid (elution suppression effect). On the other hand, it is preferable that it is 0.1-20 mass parts, More preferably, it is 0.5-10 mass parts. There exists a tendency for a sensitivity and developability to fall that the said compounding quantity is less than 0.1 mass part. On the other hand, when the amount exceeds 20 parts by mass, transparency to radiation (radiation transparency) is lowered, and it becomes difficult to obtain a rectangular (high resolution) resist pattern, and the elution suppressing effect tends to be hardly exhibited.

Moreover, the radiation sensitive resin composition may contain a solvent.
As the solvent, linear or branched ketones, cyclic ketones, propylene glycol monoalkyl ether acetates, alkyl 2-hydroxypropionate, alkyl 3-alkoxypropionate, γ-butyrolactone and the like are preferable. Used.
These solvents may be used alone or in combination of two or more.

  As said radiation sensitive resin composition, after melt | dissolving said resin (a) etc. in the said solvent so that it may become 1-25 mass% (preferably 1-20 mass%) solid content concentration, for example. For example, it is preferable to use what was prepared by filtering with a filter having a pore diameter of about 0.2 μm.

The radiation sensitive resin composition may contain an acid diffusion controller. This acid diffusion control agent is a component that controls the diffusion phenomenon of acid generated from the acid generator upon exposure in the photoresist film and suppresses an undesirable chemical reaction in the non-exposed region. Examples of such acid diffusion control agents include tertiary amine compounds, other amine compounds, amide group-containing compounds, urea compounds, and other nitrogen-containing heterocyclic compounds. These may be used individually by 1 type and may be used in combination of 2 or more type.
The content of the acid diffusion control agent is preferably 0.01 to 10 parts by mass, more preferably 0.01 to 5 parts by mass, and still more preferably 0.00 with respect to 100 parts by mass of the resin (a). It is 05-5 mass parts.

  In addition, the radiation-sensitive resin composition includes alicyclic additives, coating properties, striations, developability, and the like, which are components that further improve dry etching resistance, pattern shape, adhesion to the substrate, and the like. A surfactant that is an ingredient that improves the action of radiation, absorbs the energy of radiation, transmits the energy to the acid generator, thereby increasing the amount of acid produced, radiation sensitive resin Various additives such as a sensitizer having an effect of improving the apparent sensitivity of the composition can be contained as necessary.

  Furthermore, examples of additives other than the above include alkali-soluble resins, low-molecular alkali-solubility control agents having acid-dissociable protecting groups, antihalation agents, storage stabilizers, antifoaming agents, and the like. In addition, by blending a dye or pigment, the latent image of the exposed area can be visualized, and the influence of halation during exposure can be alleviated, and by blending an adhesion aid, adhesion to the substrate can be improved. it can.

  As the radiation-sensitive resin composition, commercially available radiation-sensitive resin compositions such as an ArF resist composition and a KrF resist composition may be used.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

[1] Preparation of defect remover (1-1) Preparation of defect remover (I) (1-1-1) Synthesis of resin for defect remover (I)
<Synthesis Example 1>
Methacrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-pentyl) ester (46.95 g, 85 mol%) and an initiator [2,2′-azobis- (2- A monomer solution prepared by dissolving 6.91 g of methyl methyl propionate) in 100 g of isopropanol was prepared. Meanwhile, 50 g of isopropanol was charged into a 500 ml three-necked flask equipped with a thermometer and a dropping funnel, and purged with nitrogen for 30 minutes. After purging with nitrogen, the inside of the flask was heated to 80 ° C. while stirring with a magnetic stirrer. Using a dropping funnel, a monomer solution prepared in advance was added dropwise over 2 hours. After completion of the dropping, the reaction was further continued for 1 hour, and 10 g of isopropanol solution of 3.05 g (15 mol%) of vinyl sulfonic acid was dropped over 30 minutes, and then the reaction was further continued for 1 hour. Subsequently, it cooled to 30 degrees C or less, and the copolymer liquid was obtained.
The obtained copolymer solution was concentrated to 150 g and then transferred to a separatory funnel. The separatory funnel was charged with 50 g of methanol and 600 g of n-hexane to carry out separation and purification. After separation, the lower layer solution was recovered. This lower layer solution was diluted with isopropanol to 100 g, and again transferred to a separatory funnel. 50 g of methanol and 600 g of n-hexane were put into the separatory funnel, separation and purification were performed, and the lower layer solution was recovered after separation. The recovered lower layer solution was replaced with 4-methyl-2-pentanol, and the total amount was adjusted to 250 g. After the adjustment, 250 g of water was added for separation and purification. After separation, the upper layer liquid was recovered. The recovered upper layer liquid was replaced with 4-methyl-2-pentanol to obtain a resin solution. In addition, the solid content concentration of the sample (resin solution) after the substitution with 4-methyl-2-pentanol was as follows: 0.3 g of the resin solution was weighed on an aluminum dish and 140 ° C. × 1 hour on a hot plate. After heating under conditions, the resin solution was calculated from the mass before heating and the mass of the residue (after heating). This solid content concentration was used for the preparation of the defect remover and the yield calculation.
The copolymer contained in the obtained resin solution had Mw of 9760, Mw / Mn of 1.51, and a yield of 65%. As a result of ¹³ C-NMR analysis, the content of each repeating unit derived from methacrylic acid (1,1,1-trifluoro-2-trifluoromethyl-2-hydroxy-4-pentyl) ester and vinylsulfonic acid Was 95: 5 (mol%). This copolymer is referred to as “resin (A-1)”.

(1-1-2) Preparation of Defect Remover (I) 100 parts of the resin (A-1) and 2800 parts of solvent (4-methyl-2-pentanol) were mixed and stirred for 2 hours. The defect remover (I) having a solid content concentration of 4% was prepared by filtration through a 200 nm filter.

In addition, the measurement of Mw, Mn, Mw / Mn, and ¹³ C-NMR analysis in the present Example were performed as follows.
<Mw and Mn>
Using Tosoh Corporation GPC columns (G2000HXL: 2, G3000HXL: 1, G4000HXL: 1), flow rate: 1.0 ml / min, elution solvent: tetrahydrofuran, column temperature: 40 ° C. It was measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard. The degree of dispersion Mw / Mn was calculated from the measurement results.
< ^13C -NMR analysis>
The ¹³ C-NMR analysis of each polymer was measured using “JNM-EX270” manufactured by JEOL Ltd.

(1-2) Preparation of defect remover (II) (1-2-1) Synthesis of resin for defect remover (II)
<Synthesis Example 2>
A stainless steel autoclave equipped with a stirrer, thermometer, heater, monomer addition pump and nitrogen gas introduction device was charged with 140 parts of butyl cellosolve, and the gas phase part was purged with nitrogen for 15 minutes. The temperature rose. Next, while maintaining the internal temperature at 80 ° C., 10 parts of 2-acrylamido-2-methylpropanesulfonic acid, 50 parts of 2,2,3,3,3-pentafluoropropyl acrylate, 40 parts of methyl methacrylate and benzoyl peroxide 2 The mixture consisting of parts was added continuously over 3 hours. After completion of the addition, the mixture was further reacted at 85 to 95 ° C. for 2 hours, and then cooled to 25 ° C. Subsequently, the solvent was removed by vacuum drying to obtain a copolymer.
The obtained copolymer had Mw of 30000, Mw / Mn of 2.5, and a yield of 84%. As a result of ¹³ C-NMR analysis, the content ratio of each repeating unit derived from 2-acrylamido-2-methylpropanesulfonic acid, 2,2,3,3,3-pentafluoropropyl acrylate and methyl methacrylate was 10 : 51:39 (mol%). This copolymer is referred to as “resin (A-2)”.

(1-2-2) Preparation of Defect Remover (II) 100 parts of the resin (A-2), 50 parts of perfluorooctane sulfonic acid, and 2800 parts of solvent (water) were mixed and stirred for 2 hours. Thereafter, the defect removing agent (II) having a solid content concentration of 4% was prepared by filtering with a filter having a pore diameter of 200 nm.

[2] Preparation of radiation-sensitive resin composition (2-1) Synthesis of resin for radiation-sensitive resin composition
<Synthesis Example 3>
The following compound (M-1) 53.93 g (50 mol%), compound (M-2) 35.38 g (40 mol%), and compound (M-5) 10.69 g (10 mol%) were converted to 2-butanone. A monomer solution was prepared by dissolving in 200 g and adding 5.58 g of dimethyl 2,2′-azobis (2-methylpropionate). On the other hand, 100 g of 2-butanone was charged into a 500 ml three-necked flask equipped with a thermometer and a dropping funnel and purged with nitrogen for 30 minutes. After purging with nitrogen, the inside of the flask was heated to 80 ° C. while stirring with a magnetic stirrer. Using a dropping funnel, a monomer solution prepared in advance was added dropwise over 3 hours. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled to 30 ° C. or less by water cooling. After cooling, it was poured into 2000 g of methanol, and the precipitated white powder was filtered off. The filtered white powder was washed twice with 400 g of methanol as a slurry. Thereafter, the mixture was filtered and dried at 50 ° C. for 17 hours to obtain a white powder copolymer (74 g, yield 74%).
The obtained copolymer had Mw of 6900 and Mw / Mn of 1.70, and as a result of ¹³ C-NMR analysis, compound (M-1), compound (M-2), and compound (M-3) The content ratio of each repeating unit derived from was a copolymer of 53.0: 37.2: 9.8 (mol%). This copolymer is referred to as “resin (a-1)”.

<Synthesis Example 4>
The following compound (M-1) 47.54 g (46 mol%), compound (M-2) 12.53 g (15 mol%), and compound (M-4) 39.93 g (39 mol%) were converted into 2-butanone. A monomer solution dissolved in 200 g and charged with 4.08 g of 2,2′-azobis (isobutyronitrile) was prepared. On the other hand, 100 g of 2-butanone was charged into a 1000 ml three-necked flask equipped with a thermometer and a dropping funnel, and purged with nitrogen for 30 minutes. After purging with nitrogen, the inside of the flask was heated to 80 ° C. while stirring with a magnetic stirrer. Using a dropping funnel, a monomer solution prepared in advance was added dropwise over 3 hours. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled to 30 ° C. or less by water cooling. After cooling, it was poured into 2000 g of methanol, and the precipitated white powder was filtered off. The filtered white powder was washed twice with 400 g of methanol as a slurry. Then, it filtered and dried at 50 degreeC for 17 hours, and obtained the copolymer of the white powder (73 g, yield 73%).
The obtained copolymer had Mw of 5700 and Mw / Mn of 1.70, and as a result of ¹³ C-NMR analysis, compound (M-1), compound (M-2), and compound (M-4) The content ratio of each repeating unit derived from was a copolymer of 51.4: 14.6: 34.0 (mol%). This is designated as resin (a-2).

(2-2) Preparation of Radiation Sensitive Resin Composition Table 1 shows the types of (a) resin, (b) acid generator and (c) acid diffusion controller in (d) solvent. Dissolved at the indicated ratio. Thereafter, the mixed solution was filtered through a membrane filter having a pore size of 0.2 μm to prepare a radiation sensitive resin composition for forming a photoresist film.

Here, the details of (b) the acid generator, (c) the acid diffusion controller and (d) the solvent described in Table 1 will be described.
<(B) Acid generator>
(B-1): Triphenylsulfonium nonafluoro-n-butanesulfonate (b-2): 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate
<(C) Acid diffusion controller>
(C-1): R-(+)-(tert-butoxycarbonyl) -2-piperidinemethanol
<(D) Solvent>
(D-1): Propylene glycol monomethyl ether acetate (d-2): Cyclohexanone

[3] Blob defect evaluation method and results
<Comparison target (Comparative Example 1)>
Using “CLEAN TRACK ACT8” (manufactured by Tokyo Electron Co., Ltd.), the radiation-sensitive resin composition prepared as described above was spin-coated on a SOG substrate prepared in advance, and then heated at 90 ° C. × 60 on a hot plate. PB was performed under the condition of seconds, and a coating film having a thickness of 120 nm was formed.
Next, using an ArF projection exposure apparatus (model number “S306C”, manufactured by Nikon Corporation), exposure was performed under optical conditions of NA: 0.78 and sigma: 0.85. After that, PEB (heating condition: 115 ° C. × 60 seconds) was performed using a hot plate of the trade name “CLEAN TRACK ACT8”, and then paddle development was performed with an LD nozzle (developer: 2.38% TMAH aqueous solution). For 30 seconds. Next, after rinsing with ultrapure water, spin drying was performed by shaking off at 4000 rpm for 15 seconds.
With respect to the substrate thus obtained, the number of blob defects was measured using a defect inspection apparatus “KLA2351” (manufactured by KLA Tencor), and the results are shown in Table 2.

<Examples 1-3>
Using “CLEAN TRACK ACT8” (manufactured by Tokyo Electron Co., Ltd.), the radiation-sensitive resin composition prepared as described above was spin-coated on a SOG substrate prepared in advance, and then heated at 90 ° C. × 60 on a hot plate. PB was performed under the condition of seconds, and a coating film having a thickness of 120 nm was formed.
Next, using an ArF projection exposure apparatus (model number “S306C”, manufactured by Nikon Corporation), exposure was performed under optical conditions of NA: 0.78 and sigma: 0.85. After that, PEB (heating condition: 115 ° C. × 60 seconds) was performed using a hot plate of the trade name “CLEAN TRACK ACT8”, and then paddle development was performed with an LD nozzle (developer: 2.38% TMAH aqueous solution). For 30 seconds. Next, after rinsing with ultrapure water, spin drying was performed by shaking off at 4000 rpm for 15 seconds.
Thereafter, a coating layer was formed by spin-coating a defect-removing agent of the type shown in Table 2 on the developed coating film, and then using a hot plate with a trade name “CLEAN TRACK ACT8” in Table 2. Heat treatment was performed under the conditions shown (note that this heat treatment was performed only in Examples 2 and 3). Next, paddle development (developer: 2.38% TMAH aqueous solution) was performed for 30 seconds using an LD nozzle. Then, it rinsed with ultrapure water and spin-dried by shaking off at 4000 rpm for 15 seconds.
With respect to the substrate thus obtained, the number of blob defects was measured using a defect inspection apparatus “KLA2351” (manufactured by KLA Tencor), and the results are shown in Table 2. In addition, the case where the number of blob defects was less than half of the comparison target was “◯”, and the case where the number was not less than half was “x”.

Claims (3)

(1) A radiation-sensitive resin composition containing a resin (a) that becomes alkali-soluble by the action of an acid and a radiation-sensitive acid generator (b) is applied on the substrate to form a coating film and exposed. Process,
(2) A step of applying a defect remover on the coating film to form a coating layer;
(3) a patterning method comprising: a developing step,
The defect remover is a repeating unit represented by the following general formula (1-1), a repeating unit represented by the following general formula (1-2), or a repeating unit represented by the following general formula (1-3). And a resin (A) containing at least one of repeating units represented by the following general formula (1-4), and a solvent (B).

[In General Formulas (1-1) to (1-4), R ¹ represents a hydrogen atom, a methyl group, or a trifluoromethyl group, and R ² , R ^3, and R ⁴ represent a single bond, a methylene group, A linear or branched alkylene group having 2 to 20 carbon atoms or a divalent cyclic hydrocarbon group, wherein R ⁵ is a linear or branched group having 1 to 10 carbon atoms and containing at least one fluorine atom. Or an alicyclic alkyl group having 3 to 10 carbon atoms, A represents a single bond, a carbonyl group, a carbonyloxy group, or an oxycarbonyl group, and B represents a single bond, a methylene group, or a carbon number of 2 -20 linear or branched alkylene groups, or a bivalent cyclic hydrocarbon group. ]   The pattern formation method of Claim 1 provided with the image development process which provides a pattern to the said coating film by image development between the said process (1) and the said process (2).   The pattern formation method of Claim 2 or 3 provided with a heat processing process between the said process (2) and the said process (3).