JP5418268B2 - Radiation sensitive resin composition - Google Patents

Description

  The present invention relates to a radiation-sensitive resin composition used as a resist material in photolithography processes such as the manufacture of semiconductors such as ICs and the manufacture of circuit boards such as liquid crystals and thermal heads. More specifically, the present invention relates to a chemically amplified radiation-sensitive resin composition that is suitably used in a photolithography process using far ultraviolet rays having a wavelength of 250 nm or less or an electron beam as an exposure light source, such as a KrF excimer laser and an ArF excimer laser. Is.

  The chemically amplified radiation-sensitive resin composition generates an acid in an exposed portion by irradiation with far ultraviolet rays such as KrF excimer laser or ArF excimer laser, EUV, or EB (electron beam). The resin in the exposed area is solubilized in an alkaline developer by a chemical reaction using this acid as a catalyst. A resist pattern is formed on the substrate using the difference in dissolution rate of the exposed portion and the unexposed portion with respect to the developer generated by this chemical reaction.

  For example, as a resist material used in a lithography process using an ArF excimer laser as a light source, a resin having an alicyclic hydrocarbon having no large absorption in the 193 nm region in the skeleton, particularly a lactone skeleton in its repeating unit. The radiation sensitive resin composition containing the resin which has is used.

  It is known that process stability can be obtained by adding a nitrogen-containing compound (hereinafter also referred to as “acid diffusion controller”) to the above-described radiation-sensitive resin composition (Patent Documents 1 to 3). 3). In particular, in order to improve the lithography performance of isolated patterns, addition of an acid diffusion control agent having a specific carbamate group has been studied (see Patent Documents 4 and 5).

  As one of the resist pattern miniaturization techniques, immersion exposure has been put into practical use, and a resist material that can cope with this has been demanded. However, in immersion exposure, the acid diffusion control agent described above elutes in the immersion liquid, which adversely affects the pattern shape. Further, the eluted acid diffusion control agent contaminates the lens of the exposure machine. It has become. In order to cope with this, studies have been made to use a resin having an acid diffusion control function containing a repeating unit having an amine skeleton as a resist material (see Patent Document 6).

  At present, when the miniaturization of the resist pattern is progressing to a level of 90 nm or less, it is not only an improvement in basic characteristics such as an improvement in the rectangularity of the resist pattern, but also an index representing the roughness of the resist pattern, for example. Performances such as reduction of LWR (Line Width Roughness) are also required. However, no resist material satisfying all of these performances has been found, and its development is expected.

JP-A-5-232706 JP-A-5-249683 JP-A-5-158239 JP 2001-166476 A JP 2001-215589 A JP 2008-133312 A

  The present invention has been made in view of such problems of the prior art, and the subject is not only basic characteristics such as sensitivity, resolution and exposure margin, but also LWR performance. The object is to provide a satisfactory radiation-sensitive resin composition.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors can achieve the above-mentioned problems by including in the resin a repeating unit having a cyclic carbonate structure together with a repeating unit having a nitrogen-containing compound structure. As a result, the present invention has been completed.

  That is, according to this invention, the radiation sensitive resin composition shown below is provided.

  [1] A polymer component (A) composed of one or two or more polymers, a radiation-sensitive acid generator (B) (hereinafter also simply referred to as “acid generator (B)”), a solvent ( C), and the polymer component (A) contains a repeating unit (a1) represented by the following general formula (a1) and a repeating unit (a2) represented by the following general formula (a2) Radiation sensitive resin composition.

In the general formulas (a1) and (a2), R ¹ independently represents a hydrogen atom or a methyl group. In the general formula (a1), R ² represents a linear divalent hydrocarbon group having 1 to 3 carbon atoms, and two R ^{3 s} independently represent a hydrogen atom or 1 to 5 carbon atoms. A linear, branched, or cyclic alkyl group, or two R ³ 's bonded to each other to form a 4- to 10-membered heterocyclic structure with the nitrogen atom to which they are bonded You may do it. In the general formula (a2), R ⁴ represents a single bond or a linear, branched or cyclic divalent hydrocarbon group having 1 to 10 carbon atoms, and A ¹ is a trivalent organic group. Indicates.

  [2] The radiation sensitive material according to [1], wherein at least one of the polymers contained in the polymer component (A) is a copolymer having the repeating unit (a1) and the repeating unit (a2). Resin composition.

  [3] At least two of the polymers contained in the polymer component (A) are the polymer having the repeating unit (a1) and the polymer having the repeating unit (a2). The radiation sensitive resin composition described in 1.

  [4] The repeating unit (a1) is a repeating unit (a1-A) represented by the following general formula (a1-A) and a repeating unit (a1-B) represented by the following general formula (a1-B): The radiation sensitive resin composition according to any one of [1] to [3], which is at least one of the following.

In the general formulas (a1-A) and (a1-B), each R ¹ independently represents a hydrogen atom or a methyl group, and each l independently represents an integer of 1 to 3. In the general formula (a1-A), m independently represents an integer of 1 to 3. In the general formula (a1-B), A ² represents an oxygen atom or an amino group, and n represents 1 or 2.

  [5] Any of [1] to [4] above, wherein the content ratio of the repeating unit (a1) is 0.01 to 20 mol% with respect to the total of all repeating units of the polymer component (A). The radiation sensitive resin composition described in 1.

  [6] The content ratio of the repeating unit (a2) is 5 to 80 mol% with respect to the total of all repeating units of the polymer component (A), according to any one of [1] to [5]. Radiation sensitive resin composition.

  [7] The radiation-sensitive resin composition according to any one of [1] to [6], wherein the polymer component (A) further contains a repeating unit (a3) represented by the following general formula (a3). object.

In the general formula (a3), R ¹ represents a hydrogen atom or a methyl group, and three R ^{5 s} are each independently a linear or branched alkyl group having 1 to 4 carbon atoms, or 4 carbon atoms. or showing a 20 alicyclic hydrocarbon group, or of the three R ^5, 2 one R ⁵ is a cycloaliphatic having 4 to 20 carbon atoms together with the carbon atom to which both are bonded to each other are attached A hydrocarbon group may be formed, and the remaining one R ⁵ may represent a linear or branched alkyl group having 1 to 4 carbon atoms.

  [8] The radiation-sensitive resin composition according to any one of [1] to [7], wherein the polymer component (A) further contains a repeating unit (a4) having a lactone skeleton.

  The radiation-sensitive resin composition of the present invention has an effect of satisfying not only basic characteristics such as sensitivity, resolution, and exposure amount margin but also LWR performance.

  Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments, and based on ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. It should be understood that modifications, improvements, and the like appropriately added to the embodiments described above fall within the scope of the present invention.

1. Radiation sensitive resin composition:
The radiation sensitive resin composition of the present invention is a composition comprising a polymer component (A), an acid generator (B), and a solvent (C). The details will be described below.

1-1. Polymer component (A):
A polymer component (A) consists of 1 type, or 2 or more types of polymers, and contains a repeating unit (a1) and a repeating unit (a2).

In the present specification, “the polymer component (A) contains the repeating unit (a1)” means that at least one of the (co) polymers contained in the polymer component (A) is a repeating unit ( means containing a1). Further, “the polymer component (A) contains the repeating unit (a1) and the repeating unit (a2)” means that the polymer component (A) includes the following embodiments (1) to (4). Means. However, in the present specification, “(co) polymer” is a concept including both a homopolymer composed of one type of repeating unit and a copolymer composed of two or more types of repeating units. In addition, the “other (co) polymer” in the aspect (4) refers to a (co) polymer that does not contain any of the repeating unit (a1) and the repeating unit (a2).
(1) Copolymer containing repeating unit (a1) and repeating unit (a2) (2) (Co) polymer containing repeating unit (a1) and (co) heavy containing repeating unit (a2) (3) The (1) copolymer, the (co) polymer containing the repeating unit (a1) and the (co) polymer containing the repeating unit (a2). (Co) polymer mixture with at least one (co) polymer (4) (1) copolymer, (2) (co) polymer mixture, or (3) (co) polymer (Co) polymer mixture of coalescence mixture and other (co) polymers

  As the polymer component (A), it is preferable that at least one of the polymers contained in the polymer component (A) is a copolymer having the repeating unit (a1) and the repeating unit (a2).

  In addition, as the polymer component (A), at least two of the polymers contained in the polymer component (A) are a polymer having the repeating unit (a1) and a polymer having the repeating unit (a2). It is also preferable that it is a coalescence.

1-1-1. Repeating unit (a1):
The polymer component (A) obtains an acid diffusion control function by containing the repeating unit (a1) having a nitrogen atom as represented by the general formula (a1), and the acid-sensitive resin composition has an acid. There is no need to add a diffusion control agent. Thus, when this radiation-sensitive resin composition is used as a resist material for immersion exposure, the acid diffusion control agent does not elute into the immersion liquid. Contamination of the diffusion control agent to the lens of the exposure machine can be prevented.

Specific examples of the “linear divalent hydrocarbon group having 1 to 3 carbon atoms” represented by R ² in the general formula (a1) include a methylene group, an ethylene group, a 1,3-propylene group, and the like. Can be mentioned.

Specific examples of the “linear, branched or cyclic alkyl group having 1 to 5 carbon atoms” represented by R ³ in the general formula (a1) include a methyl group, an ethyl group, an n-propyl group, Examples thereof include an n-butyl group, a pentyl group, an i-propyl group, an i-butyl group, a t-butyl group, an i-pentyl group, a neopentyl group, a cyclopropyl group, a cyclobutyl group, and a cyclopentyl group. Among these, a methyl group, an ethyl group, and the like are preferable from the viewpoint that the polymerizability of the monomer that gives the repeating unit (a1) can be improved.

In the general formula (a1), two R ³ may combine with each other to form a "heterocyclic structure having 4 to 10 membered ring" to which both are formed together with the nitrogen atom to which they are bonded, in addition to the nitrogen atom A heterocyclic ring containing an atom other than a carbon atom is preferred. It is also preferred that the carbon atom adjacent to the nitrogen atom is substituted with a carbonyl group. Specific examples of such a heterocyclic structure include ring structures represented by the following formulas (a1-b1) to (a1-b4).

  The repeating unit (a1) is at least one of the repeating unit (a1-A) represented by the general formula (a1-A) and the repeating unit (a1-B) represented by the general formula (a1-B). It is preferable that

  The repeating unit (a1) is a repeating unit represented by the following general formulas (a1-A-1) to (a1-A-3), (a1-B-1), or (a1-B-2). It is particularly preferred that

In the general formulas (a1-A-1) to (a1-A-3), (a1-B-1), and (a1-B-2), each R ¹ independently represents a hydrogen atom or a methyl group. Indicates. In addition, a repeating unit (a1) can be used individually by 1 type or in combination of 2 or more types.

1-1-2. Repeating unit (a2):
The polymer component (A) contains a repeating unit (a2) having a cyclic carbonate structure represented by the general formula (a2), so that the polymer component (A) can be used in a resist including a polymer having a basic substituent. A resist pattern excellent in image quality and LWR performance can be formed.

Specific examples of the “linear, branched or cyclic divalent hydrocarbon group having 1 to 10 carbon atoms” represented by R ⁴ in the general formula (a2) include a methylene group, an ethylene group, and propylene. Group (1,3-propylene group, 1,2-propylene group), tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene 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, ethylidene group Chain hydrocarbon groups such as 1-propylidene group and 2-propylidene group; cyclobutylene groups such as 1,3-cyclobutylene group, cyclopentylene groups such as 1,3-cyclopentylene group, 1,4 A monocyclic hydrocarbon ring group such as a cycloalkylene group having 3 to 10 carbon atoms including a cyclohexylene group such as a cyclohexylene group and a cyclooctylene group such as a 1,5-cyclooctylene group; Carbonization of 2 to 4 cyclic carbon atoms such as norbornylene group such as norbornylene group and 2,5-norbornylene group, adamantylene group such as 1,5-adamantylene group and 2,6-adamantylene group, etc. Examples thereof include a bridged cyclic hydrocarbon ring group such as a hydrogen ring group. Among these, a methylene group and the like are preferable from the viewpoint that it is easy to obtain a monomer that gives the repeating unit (a2).

In the general formula (a2), as the "trivalent organic group" represented by A ^1, for example, trivalent chain-like hydrocarbon group having 1 to 30 carbon atoms, cycloaliphatic trivalent having 3 to 30 carbon atoms Examples thereof include a cyclic hydrocarbon group and a trivalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Note that these hydrocarbon groups may have an oxygen atom, a carbonyl group, an imino group, or the like in the skeleton, or may have a substituent such as a hydroxyl group. However, the repeating unit (a2), together with a part of the "trivalent organic group" represented by A ^1, must always have a partial structure represented by the following formula (a2-a).

  In the general formula (a2-a), k represents an integer of 1 to 4.

  The repeating unit (a2) is particularly preferably a repeating unit represented by the following general formulas (a2-1) to (a2-12).

In the general formulas (a2-1) to (a2-12), R ¹ represents a hydrogen atom or a methyl group. In addition, a repeating unit (a2) can be used individually by 1 type or in combination of 2 or more types.

1-1-3. Repeating unit (a3):
The polymer component (A) preferably contains a polymer containing at least the repeating unit (a3) represented by the general formula (a3). That is, it is preferable that the polymer component (A) contains the repeating unit (a3) represented by the general formula (a3) in addition to the above-described repeating units (a1) and (a2). The “polymer containing at least the repeating unit (a3)” may be a polymer containing the above-mentioned repeating unit (a1), (a2), or both, and may not contain a polymer. May be.

  The repeating unit (a3) is a repeating unit having an acid-dissociable group, and a polymer containing such a repeating unit (a3) reacts with an acid to release the acid-dissociable group, thereby causing alkali solubility. It becomes. Therefore, the polymer component (A) can improve the resolution performance of the resist by containing the repeating unit (a3).

Specific examples of the “linear or branched alkyl group having 1 to 4 carbon atoms” represented by R ⁵ in the general formula (a3) include a methyl group, an ethyl group, an n-propyl group, and i-propyl. Group, n-butyl group, i-butyl group and t-butyl group.

In the general formula (a3), one R ⁵ or two R ⁵ are bonded to each other and formed together with the carbon atom to which both are bonded, “C 4-20 alicyclic carbonization” Specific examples of “hydrogen group” include cycloalkyl groups such as cyclobutyl group, cyclopentyl group, cyclohexyl group and cyclooctyl group; bridged polycyclic hydrocarbon groups such as tricyclodecyl group, tetracyclodecyl group and adamantyl group, etc. Can be mentioned.

  The repeating unit (a3) is particularly preferably a repeating unit represented by the following general formulas (a3-1) to (a3-18).

In the general formulas (a3-1) to (a3-18), R ¹ represents a hydrogen atom or a methyl group. In addition, a repeating unit (a3) can be used individually by 1 type or in combination of 2 or more types.

1-1-4. Repeating unit (a4):
The polymer component (A) preferably contains a polymer containing at least the repeating unit (a4) having a lactone skeleton. That is, it is preferable that the polymer component (A) contains a repeating unit (a4) having a lactone skeleton in addition to the above-described repeating units (a1) to (a3). The “polymer containing at least the repeating unit (a4)” is a polymer containing at least one repeating unit selected from the group consisting of the above-mentioned repeating units (a1), (a2), and (a3). It may be a polymer or a polymer not containing it.

  When the polymer component (A) contains the repeating unit (a4) represented by at least one of the following general formulas (a4-A) to (a4-E), the rigidity of the resist pattern is increased. The resolution and the rectangularity of the resist pattern can be improved.

In the general formulas (a4-A) to (a4-E), R ¹ represents a hydrogen atom or a methyl group. In the general formula (a4-A), R ⁶ represents a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, and p represents an integer of 1 to 3. In the general formulas (a4-D) and (a4-E), R ⁷ represents a hydrogen atom or an oxygen atom-containing hydrocarbon group. In the general formulas (a4-B) to (a4-E), A ³ represents a single bond, a methylene group, or an ethylene group. In the general formulas (a4-C) and (a4-E), A ⁴ represents a methylene group or an oxygen atom. In the general formulas (a4-B) and (a4-C), q represents 0 or 1.

In the general formula (a4-A), specific examples of the “C1-C4 linear or branched alkyl group” represented by R ⁶ include a methyl group, an ethyl group, an n-propyl group, i -Propyl group, n-butyl group, i-butyl group, t-butyl group and the like can be mentioned.

In the general formulas (a4-D) and (a4-E), specific examples of the “oxygen atom-containing hydrocarbon group” represented by R ⁷ include a methoxy group, an ethoxy group, and an acetoxy group. The bonding site of the group represented by R ⁷ is a part other than the lactone ring from the viewpoint of maintaining the solubility of the lactone ring in alkali, and the linking group (A ³ ) with the polymer main chain is bonded. A carbon atom adjacent to the carbon atom is preferred.

  As specific examples of the repeating unit (a4), repeating units represented by the following general formulas (a4-1) to (a4-8) are particularly preferable.

In the general formulas (a4-1) to (a4-8), R ¹ represents a hydrogen atom or a methyl group. In addition, a repeating unit (a4) can be used individually by 1 type or in combination of 2 or more types.

1-1-5. Repeating unit (a5):
The polymer component (A) can be copolymerized with these in addition to the above repeating units (a1) to (a4), and is a repeating unit derived from (meth) acrylic acid ester (hereinafter referred to as “repeating unit (a5)”. ) ”) May be contained within a range not impairing the effects of the present invention. As such a repeating unit (a5), a repeating unit having a hydrophilic group is preferable from the viewpoint of improving resist developability, resistance to pattern peeling, and the like. Specific examples of the repeating unit having a hydrophilic group include repeating units represented by the following general formulas (a5-1) to (a5-14).

In the general formulas (a5-1) to (a5-14), R ¹ represents a hydrogen atom or a methyl group.

As the repeating unit (a5), in addition to the general formulas (a5-1) to (a5-14), methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, lauryl (meth) ) Acrylate, (meth) acrylic acid cyclohexyl, (meth) acrylic acid-bicyclo [2.2.1] heptyl ester, (meth) acrylic acid-cyclohexyl ester, (meth) acrylic acid-bicyclo [4.4.0] Decanyl ester, (meth) acrylic acid-bicyclo [2.2.2] octyl ester, (meth) acrylic acid-tricyclo [5.2.1.0 ^2,6 ] decanyl ester, (meth) acrylic acid- Contains alkyl (meth) acrylates such as adamantyl, (meth) acrylic acid-tricyclo [3.3.1.1 ^3,7 ] decanyl ester May be. In addition, a repeating unit (a5) can be used individually by 1 type or in combination of 2 or more types.

1-1-6. Content ratio:
In the polymer component (A), the content of the repeating unit (a1) is preferably 0.01 to 20 mol%, more preferably 0.01 to 10 mol%, based on the total of all repeating units. Preferably, it is 0.01-5 mol% especially preferable. When the content ratio of the repeating unit (a1) is 0.01 to 20 mol%, the resolution performance of the resist can be improved and a good resist pattern can be formed. In the present specification, the “total of all repeating units” means the total of all repeating units contained in the polymer component (A). That is, when the polymer component (A) includes a plurality of polymers, it means the total (total) of all repeating units contained in all the polymers.

  In the polymer component (A), the content ratio of the repeating unit (a2) is preferably 5 to 80 mol%, more preferably 20 to 70 mol%, based on the total of all repeating units, 30 to Particularly preferred is 50 mol%. When the content ratio of the repeating unit (a2) is 5 to 80 mol%, the resolution performance and low LWR property of the resist can be improved.

  In the polymer component (A), the content ratio of the repeating unit (a3) is preferably 5 to 80 mol%, more preferably 10 to 80 mol%, more preferably 20 to 20 mol% based on the total of all repeating units. It is especially preferable that it is 70 mol%.

  In the polymer component (A), the content ratio of the repeating unit (a4) is preferably 70 mol% or less with respect to the total of all repeating units.

  In the polymer component (A), the content of the repeating unit (a5) is preferably 50 mol% or less with respect to the total of all repeating units.

1-1-7. polymerization:
The method for polymerizing the polymer contained in the polymer component (A) is not particularly limited, and conventionally known radical polymerization methods can be applied. For example, a method (1) in which a solution containing a monomer and a radical initiator is dropped into a polymerization solvent or a solution containing a monomer to cause a polymerization reaction; a solution containing the monomer and a radical initiator A method (2) in which each of the contained solutions is dropped separately into a polymerization solvent or a monomer-containing solution to cause a polymerization reaction; a plurality of types of solutions each containing one type of each monomer; and radical initiation It is preferable to perform polymerization by a method such as a method (3) in which a solution containing an agent is separately dropped into a solution containing a polymerization solvent or a monomer to cause a polymerization reaction.

  In addition, when the solution containing the monomer is dropped and reacted with the solution containing the monomer, the ratio of the monomer in the dropped solution is the sum of all monomers used for the polymerization. On the other hand, it is preferably 30 mol% or more, more preferably 50 mol% or more, and particularly preferably 70 mol% or more.

  When polymerizing by the above-described methods, the reaction temperature may be appropriately determined according to the type of radical initiator, and is usually 30 to 180 ° C, preferably 40 to 160 ° C, and preferably 50 to 140 ° C. More preferably.

  The dropping time may be appropriately determined according to the reaction temperature, the type of radical initiator, the type of monomer, the amount, etc., and is usually 30 minutes to 8 hours, preferably 45 minutes to 6 hours. 1 to 5 hours is more preferable. Further, the total reaction time from the start of dropping may be appropriately determined according to the same conditions as the dropping time, and is usually 30 minutes to 8 hours, preferably 45 minutes to 7 hours, preferably 1 to 6 hours. More preferably it is.

  As radical initiators, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2-cyclopropylpropionitrile), 2,2′-azobis (2 , 4-dimethylvaleronitrile) and the like. These radical initiators can be used alone or in combination of two or more.

  As the polymerization solvent, any known polymerization solvent can be used without particular limitation as long as it can dissolve the monomer and does not inhibit the polymerization. For example, alcohols, ethers, ketones, amides can be used. , Esters / lactones, nitriles and the like. These polymerization solvents can be used alone or in combination of two or more. Examples of the solvent that inhibits polymerization include nitrobenzene having a polymerization inhibiting effect, mercapto compound having a chain transfer effect, and the like.

  The polymer obtained by the above polymerization reaction is preferably purified by a reprecipitation method. That is, after completion of the polymerization reaction, the polymer is purified as a powder by putting the polymerization solution into a reprecipitation solvent.

  In addition to the reprecipitation method, the polymer can also be purified by removing impurities by a liquid separation operation. That is, after completion of the polymerization reaction, the polymerization solution is appropriately concentrated, for example, a solvent system that separates into two liquids such as methanol / heptane is added, impurities are removed from the polymerization solution, and a necessary solvent system (such as propylene glycol monomethyl ether) ) To purify the target polymer as a solution.

  The content ratio of the low molecular weight component remaining in the polymer solution obtained by the above-described purification is preferably 0.1% by mass or less, more preferably 0.07% by mass or less, based on the total amount of the polymer. Preferably, it is particularly preferably 0.05% by mass or less. When the content ratio of the low molecular weight component is 0.1% by mass or less, the amount of eluate in the immersion liquid is reduced during immersion exposure, and foreign matter does not precipitate during resist storage. Even when the resist is applied, there is an effect that uneven application does not occur. That is, defects at the time of resist pattern formation can be sufficiently suppressed. In addition, the amount of low molecular weight components is a value quantified by analysis by high performance liquid chromatography (HPLC).

  In the present specification, the “low molecular weight component” means a residual monomer, an oligomer derived from the residual monomer, and the like, and a polystyrene-reduced mass average molecular weight (hereinafter referred to as “Mw”) by gel permeation chromatography (GPC). "Describe" means a component of 500 or less. Specific examples of the low molecular weight component include monomers and oligomers such as dimers and trimers. These low molecular weight components can be removed by the chemical purification method described above or a method in which these chemical purification methods are combined with a physical purification method such as ultrafiltration or centrifugation.

  The Mw in terms of polystyrene by GPC of the polymer contained in the polymer component (A) is not particularly limited, but is preferably 1,000 to 100,000, and more preferably 1,000 to 30,000. Preferably, it is 1,000-20,000. If the Mw of the polymer is less than 1,000, the heat resistance when used as a resist tends to decrease. On the other hand, if the Mw of the polymer exceeds 100,000, the developability when used as a resist tends to decrease.

  The ratio (Mw / Mn) of Mw to the number average molecular weight (hereinafter referred to as “Mn”) in terms of polystyrene by GPC of the polymer contained in the polymer component (A) is usually 1.0 to 5.0. It is preferable that it is 1.0-3.0, and it is still more preferable that it is 1.0-2.0.

1-2. Acid generator (B):
The radiation-sensitive acid generator generates an acid upon irradiation with radiation. By this acid, the acid dissociable group in the polymer contained in the polymer component (A) is deprotected (dissociated), and the polymer becomes alkali-soluble. As an acid generator (B), a conventionally well-known radiation sensitive acid generator can be used without a restriction | limiting in particular.

  The acid generator (B) preferably contains an acid generator (B1) represented by the following general formula (B1).

In the general formula (B1), R ⁸ represents a hydrogen atom, a fluorine atom, a hydroxyl group, an alkyl group having 1 to 10 carbon atoms, an alkoxyl group having 1 to 10 carbon atoms, or an alkoxycarbonyl group having 2 to 11 carbon atoms. , R ⁹ represents an alkyl group having 1 to 10 carbon atoms, an alkoxyl group having 1 to 10 carbon atoms, or an alkanesulfonyl group having 1 to 10 carbon atoms, and each R ¹⁰ independently has 1 to 10 carbon atoms. An alkyl group, a phenyl group, or a naphthyl group is shown. However, two R ¹⁰ may be bonded to each other to form a divalent group having 2 to 10 carbon atoms. s represents an integer of 0 to 2, r represents an integer of 0 to 10, and X ⁻ represents an anion represented by the following general formulas (b1) to (b4).

In the general formulas (b1) and (b2), R ¹¹ represents a hydrogen atom, a fluorine atom, or a hydrocarbon group having 1 to 12 carbon atoms. In the general formula (b1), t represents an integer of 1 to 10. In said general formula (b3) and (b4), R < ¹² > shows a C1-C10 fluorine substituted alkyl group each independently. However, two R < ¹² > may couple | bond together and may form a C2-C10 bivalent fluorine substituted alkylene group.

  As a cation of the acid generator (B1), triphenylsulfonium cation, tri-1-naphthylsulfonium cation, tri-tert-butylphenylsulfonium cation, 4-fluorophenyl-diphenylsulfonium cation, di-4-fluorophenyl-phenyl Sulfonium cation, tri-4-fluorophenylsulfonium cation, 4-cyclohexylphenyl-diphenylsulfonium cation, 4-methanesulfonylphenyl-diphenylsulfonium cation, 4-cyclohexanesulfonyl-diphenylsulfonium cation, 1-naphthyldimethylsulfonium cation, 1-naphthyl Diethylsulfonium cation, 1- (4-hydroxynaphthyl) dimethylsulfonium cation, 1- (4-methylnaphthane Til) dimethylsulfonium cation, 1- (4-methylnaphthyl) diethylsulfonium cation, 1- (4-cyanonaphthyl) dimethylsulfonium cation, 1- (4-cyanonaphthyl) diethylsulfonium cation, 1- (3,5-dimethyl) -4-hydroxyphenyl) tetrahydrothiophenium cation, 1- (4-methoxynaphthyl) tetrahydrothiophenium cation, 1- (4-ethoxynaphthyl) tetrahydrothiophenium cation, 1- (4-n-propoxynaphthyl) Tetrahydrothiophenium cation, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium cation, 2- (7-methoxynaphthyl) tetrahydrothiophenium cation, 2- (7-ethoxynaphthyl) tetrahydrothioff Cation, 2- (7-n- propoxy-naphthyl) tetrahydrothiophenium cation, 2- (7-n- butoxynaphthyl) tetrahydrothiophenium cation, and the like are preferable.

  Examples of the anion of the general formula (B1) include trifluoromethanesulfonate anion, perfluoro-n-butanesulfonate anion, perfluoro-n-octanesulfonate anion, 2- (bicyclo [2.2.1] hept-2-yl ) -1,1,2,2-tetrafluoroethanesulfonate anion, 2- (bicyclo [2.2.1] hept-2-yl) -1,1-difluoroethanesulfonate anion, 1-adamantylsulfonate anion, Anions and the like represented by the following formulas (b3-a) to (b3-g) are preferable.

  The acid generator (B) is composed of a combination of the above-described cation and anion. However, the combination is not particularly limited.

  As the acid generator (B), in addition to the acid generator (B1), other acid generators may be used in combination. Examples of other acid generators include onium salt compounds, halogen-containing compounds, diazoketone compounds, sulfone compounds, and sulfonic acid compounds.

  These acid generators can be used singly or in combination of two or more.

  In the radiation sensitive resin composition of the present invention, the blending ratio of the acid generator (B) is usually 100 parts by mass of the polymer component (A) from the viewpoint of ensuring the sensitivity and developability as a resist. It is 0.1-30 mass parts, and it is preferable that it is 0.5-20 mass parts. There exists a tendency for a sensitivity and developability to fall that the mixture ratio of an acid generator (B) is less than 0.1 mass part. On the other hand, when the blending ratio of the acid generator (B) is more than 30 parts by mass, the transparency to radiation is lowered, and it is difficult to obtain a rectangular resist pattern. Moreover, it is preferable that the usage-amount of another acid generator is 80 mass% or less with respect to the whole quantity of an acid generator (B), and it is still more preferable that it is 60 mass% or less.

1-3. Solvent (C):
As the solvent (C), a conventionally known solvent can be used without particular limitation as long as it is a solvent capable of dissolving the polymer component (A), the acid generator (B), and optionally the additive. , Alcohols, ethers, ketones, amides, esters / lactones, nitriles and the like.

  Specific examples of the solvent (C) include propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate, ketones such as cyclohexanone, alkyl 2-hydroxypropionate, alkyl 3-alkoxypropionate, and γ-butyrolactone. Are preferred, propylene glycol monomethyl ether acetate, cyclohexanone, γ-butyrolactone and the like are more preferred, and propylene glycol monomethyl ether acetate is particularly preferred. In addition, these solvents can be used individually by 1 type or in mixture of 2 or more types.

  In the radiation-sensitive resin composition, the proportion of the solvent (C) is preferably such that the solid content concentration of the polymer component (A) is 3 to 30% by mass, and further the proportion of 3 to 20% by mass. A ratio of 3 to 15% by mass is particularly preferable.

1-4. Additive:
The radiation sensitive resin composition of the present invention may contain an additive as desired. Examples of such additives include surfactants, sensitizers, aliphatic additives, fluorine-containing resins, dyes, pigments, adhesion aids, antihalation agents, storage stabilizers, antifoaming agents, and the like. be able to. Moreover, a low molecular nitrogen-containing compound can also be used as an acid diffusion control agent as long as the effects of the present invention are not impaired.

(1) Surfactant:
The surfactant is a component that exhibits an effect of improving resist coatability, striation, developability, and the like.

  In addition, you may use these surfactant individually by 1 type or in combination of 2 or more types.

  The blending ratio of the surfactant is preferably 0.001 to 2 parts by mass with respect to 100 parts by mass of the polymer component (A).

(2) Sensitizer:
The sensitizer absorbs radiation energy and transmits the absorbed energy to the acid generator (B) to increase the amount of acid generated. The apparent sensitivity of the radiation-sensitive resin composition It has the effect of improving sensitivity.

  Examples of the sensitizer include carbazoles, acetophenones, benzophenones, naphthalenes, phenols, biacetyl, eosin, rose bengal, pyrenes, anthracenes, and phenothiazines.

  In addition, you may use these sensitizers individually by 1 type or in combination of 2 or more types.

  The blending ratio of the sensitizer is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the polymer component (A).

(3) Aliphatic additive:
The alicyclic additive is a component having an action of further improving dry etching resistance, pattern shape, adhesion to the substrate, and the like.

Specific examples of the alicyclic additive include 1-adamantanecarboxylic acid, 2-adamantanone, 1-adamantanecarboxylic acid t-butyl, 1-adamantanecarboxylic acid t-butoxycarbonylmethyl, 1-adamantanecarboxylic acid α-butyrolactone Ester, 1,3-adamantane dicarboxylate di-t-butyl, 1-adamantane acetate t-butyl, 1-adamantane acetate t-butoxycarbonylmethyl, 1,3-adamantane diacetate di-t-butyl, 2,5- Adamantane derivatives such as dimethyl-2,5-di (adamantylcarbonyloxy) hexane; deoxycholic acid t-butyl, deoxycholic acid t-butoxycarbonylmethyl, deoxycholic acid 2-ethoxyethyl, deoxycholic acid 2-cyclohexyloxy Ethyl, deoxycholic acid -Deoxycholic acid esters such as oxocyclohexyl, deoxycholic acid tetrahydropyranyl, deoxycholic acid mevalonolactone ester; lithocholic acid t-butyl, lithocholic acid t-butoxycarbonylmethyl, lithocholic acid 2-ethoxyethyl, lithocholic acid 2 -Lithocholic acid esters such as cyclohexyloxyethyl, lithocholic acid 3-oxocyclohexyl, lithocholic acid tetrahydropyranyl, lithocholic acid mevalonolactone ester; dimethyl adipate, diethyl adipate, dipropyl adipate, di-n-butyl adipate, Alkyl carboxylic acid esters such as di-t-butyl adipate and 3- [2-hydroxy-2,2-bis (trifluoromethyl) ethyl] tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecane and the like. In addition, you may use these alicyclic additives individually by 1 type or in combination of 2 or more types.

  The blending ratio of the alicyclic additive is preferably 0.5 to 20 parts by mass with respect to 100 parts by mass of the polymer component (A). There exists a possibility that the heat resistance of the formed resist film may fall that the compounding ratio of an alicyclic additive exceeds 20 mass parts.

(4) Fluorine-containing resin:
The fluorine-containing resin exhibits an effect of developing water repellency on the resist film surface, particularly in immersion exposure. In addition, the fluorine-containing resin suppresses the dissolution of various components in the radiation-sensitive resin composition from the resist film to the immersion liquid, and does not leave droplets even when immersion exposure is performed by high-speed scanning. Therefore, as a result, it is a component having the effect of suppressing defects derived from immersion exposure such as watermark defects.

The fluorine-containing resin is not particularly limited, and examples thereof include the following fluorine-containing resins.
(1) Fluorine-containing resin that is insoluble in alkali but becomes alkali-soluble by the action of acid (2) Fluorine-containing resin that is alkali-soluble but increases in alkali-solubility by the action of acid (3) Fluorine-containing resin that becomes alkali-soluble by the action of alkali (4) Fluorine-containing resin that is alkali-soluble but increases its alkali-solubility by the action of alkali

  Examples of the fluorine-containing resin include a resin containing at least one of the above-mentioned repeating unit (4) and a fluorine-containing repeating unit described later. The fluorine-containing resin further contains at least one repeating unit selected from the group consisting of the repeating units (1), (2), (3), (5), and (6). Is preferred.

  Examples of the monomer that gives a fluorine-containing repeating unit include trifluoromethyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, perfluoroethyl (meth) acrylate, and the like.

  As the fluorine-containing resin, resins (D-1) to (D-6) having groups of repeating units represented by the following general formulas (D-1) to (D-6) are preferable. In addition, these fluorine-containing resin can be used individually by 1 type or in combination of 2 or more types. Moreover, it is preferable that the content rate of a fluorine atom is 5-50 mass% in these fluorine-containing resin.

  It is preferable that the content rate of fluorine-containing resin is 0.5-20 mass with respect to 100 mass parts of polymer components (A). If the content ratio of the fluorine-containing resin is more than 20 parts by mass, the resolution performance of the resist may be deteriorated.

  In the radiation-sensitive resin composition of the present invention, the total amount of additives is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the polymer component (A).

2. Resist pattern formation:
The radiation sensitive resin composition of the present invention is useful as a material capable of forming a chemically amplified resist film, and can form a positive resist pattern having a desired shape.

  In order to form a resist pattern using the radiation sensitive resin composition of the present invention, first, the aforementioned polymer component (A), acid generator (B), solvent (C), and optionally additives are mixed. For example, a resist film is formed by applying a radiation-sensitive resin composition filtered through a filter having a pore diameter of 200 nm on a substrate. Thereafter, in some cases, heat treatment (hereinafter referred to as “PB”) may be performed at a temperature of about 70 to 160 ° C.

  As the radiation-sensitive resin composition, for example, a composition obtained by adjusting the total solid content concentration and then filtering with a filter having a pore diameter of about 0.2 μm can be used. As the substrate, for example, a silicon wafer, a wafer coated with aluminum, or the like can be used. As a method for applying the radiation-sensitive resin composition, conventionally known methods can be appropriately employed, and specific examples include spin coating, cast coating, roll coating, and the like.

  In the present invention, in order to maximize the potential of the radiation-sensitive resin composition, for example, as disclosed in Japanese Patent Publication No. 6-12452 (Japanese Patent Laid-Open No. 59-93448) and the like, An organic or inorganic antireflection film may be formed thereon. Further, in order to prevent the influence of basic impurities contained in the environmental atmosphere, a protective film can be provided on the resist film as disclosed in, for example, JP-A-5-188598. These techniques can be used in combination.

  When immersion exposure is performed, an immersion protection insoluble immersion film may be provided on the resist film in order to prevent the immersion liquid and the resist film from coming into direct contact. As the protective film for immersion, a solvent-removable protective film that is peeled off by a solvent before the developing step described later (see, for example, JP-A-2006-227632), a developer-peelable type that is peeled off by a developer in the developing step Any of the protective films (for example, see International Publication No. 2005/069096 pamphlet and International Publication No. 2006/035790 pamphlet) may be used. However, from the viewpoint of throughput, it is preferable to use a developer peeling type immersion protective film.

  Next, this resist film is exposed through an immersion liquid such as water so that a predetermined resist pattern is formed. By this exposure, an acid is generated from the radiation-sensitive acid generator in the exposed portion, and the acid-dissociable group in the polymer is deprotected (dissociated) to become alkali-soluble.

  Examples of radiation that can be used for this exposure include (extreme) far ultraviolet rays such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), EUV (extreme ultraviolet light, wavelength 13.5 nm, etc.), and synchro Examples thereof include X-rays such as tron radiation, and charged particle beams such as EB (electron beam). Moreover, exposure conditions, such as exposure amount, can be suitably selected according to the composition of the radiation-sensitive resin composition, the type of additive, and the like.

  After the exposure, heat treatment (hereinafter also referred to as “PEB”) is preferably performed. By this PEB, it becomes possible to proceed more smoothly the elimination of the acid-dissociable group in the polymer contained in the polymer component (A). The heating condition of PEB can be appropriately selected depending on the composition of the radiation sensitive resin composition, but is preferably 30 to 200 ° C, and more preferably 50 to 170 ° C.

  Next, the exposed resist film is developed. That is, the exposed portion of the resist film that has become alkali-soluble by exposure is dissolved in an alkaline developer, and the resist film in the exposed portion is removed. Finally, by washing and drying, a positive resist pattern in which the resist film remains only in the non-exposed area is obtained.

  Examples of the developer used for development include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, and di-n-propylamine. , Triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- An alkaline aqueous solution in which at least one of alkaline compounds such as [4.3.0] -5-nonene is dissolved is preferable.

  The concentration of the alkaline aqueous solution is preferably 10% by mass or less. If the concentration of the alkaline aqueous solution is more than 10% by mass, the unexposed area may be dissolved in the developer. Further, specifically, the developer preferably has a pH of 8 to 14, and more preferably a pH of 9 to 14.

  For example, an organic solvent can be added to the developer. Examples of organic solvents include ketones such as acetone, methyl ethyl ketone, methyl i-butyl ketone, cyclopentanone, cyclohexanone, 3-methylcyclopentanone, and 2,6-dimethylcyclohexanone; methyl alcohol, ethyl alcohol, n-propyl alcohol Alcohols such as i-propyl alcohol, n-butyl alcohol, t-butyl alcohol, cyclopentanol, cyclohexanol, 1,4-hexanediol and 1,4-hexanedimethylol; ethers such as tetrahydrofuran and dioxane; Examples thereof include 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 alone or in combination of two or more.

  The blending amount of the organic solvent is preferably 100 parts by volume or less with respect to 100 parts by volume of the alkaline aqueous solution. If the blending amount is more than 100 parts by volume, the developability is lowered, and there is a possibility that the remaining development in the exposed part increases. An appropriate amount of a surfactant or the like can be added to the developer.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. “%” In Examples and Comparative Examples is based on mass unless otherwise specified. Moreover, the measuring method of various physical-property values and the evaluation method of various characteristics are shown below.

[Mass average molecular weight (Mw) and number average molecular weight (Mn)]
Using GPC columns (2 G2000HXL, 1 G3000HXL, 1 G4000HXL, manufactured by Tosoh Corporation), monodisperse under analytical conditions of flow rate: 1.0 ml / min, elution solvent: tetrahydrofuran, column temperature: 40 ° C. It was measured by gel permeation chromatography (GPC) using polystyrene as a standard.

[ ¹ H-NMR analysis and ¹³ C-NMR analysis]
Measurement was performed using a nuclear magnetic resonance apparatus (trade name “JNM-ECX400”, manufactured by JEOL Ltd.).

[Sensitivity (unit: mJ / cm ² )]
A lower antireflection film having a film thickness of 77 nm was formed on the surface of a wafer having a diameter of 8 inches using a lower antireflection film forming agent (trade name “ARC29A”, manufactured by Nissan Chemical Industries, Ltd.). The surface of the lower antireflection film was applied by spin coating the radiation sensitive resin composition. Next, a SB (Soft Bake) was performed on the hot plate at a temperature shown in Table 2 for 60 seconds to form a resist film having a thickness of 150 nm.

  Using this resist film, a full-field reduction projection exposure apparatus (trade name “NSR-S306C”, manufactured by Nikon Corporation, light source: ArF excimer laser, numerical aperture: 0.78) was used. The film was exposed through a mask giving a 1 line and space (hereinafter also referred to as “75 nm 1L1S”) pattern. Subsequently, PEB (Post Exposure Bake) was performed for 60 seconds at the temperature shown in Table 2 below, followed by development with an aqueous 2.38 mass% tetramethylammonium hydroxide solution at 25 ° C. for 30 seconds. Thereafter, it was washed with water and dried to form a positive resist pattern.

The exposure amount (mJ / cm ² ) when this resist pattern was formed to be 75 nm1L1S was regarded as the optimum exposure amount, and this optimum exposure amount was evaluated as “sensitivity (mJ / cm ² )”. For measuring the resist pattern, a scanning electron microscope (trade name “S9260”, manufactured by Hitachi High-Technologies Corporation) was used.

[LWR]
In the sensitivity evaluation method described above, a resist pattern of 75 nm1L1S was resolved at an optimal exposure amount through a mask that gave a 75 nm1L1S pattern. This resist pattern was photographed at a magnification of 120,000 using a scanning electron microscope (trade name “S9260”, manufactured by Hitachi High-Technologies Corporation) from a direction perpendicular to the substrate. In the photographed image, the line width of the line portion was measured at arbitrary 10 points. The 3 sigma value obtained from the line width of the measured line part was defined as LWR (nm), and when LWR was 9.0 nm or less, it was evaluated as “good”, and when LWR was more than 9.0 nm, it was evaluated as “bad”. . The “3 sigma value” is a value obtained by multiplying the standard deviation (sigma value) obtained from the line width of the line portion at any 10 measured points by 3 times.

(Synthesis Example 1) Synthesis of polymer (A-1):
30.31 g (55 mol%) of a monomer (M3-1) represented by the following formula (M3-1) and 19.66 g of a monomer (M2-1) represented by the following formula (M2-1) (44.9 mol%) and 0.07 g (0.1 mol%) of a monomer (M1-1) represented by the following formula (M1-1) are dissolved in 180 g of 2-butanone, and used as an initiator. 1.93 g (5 mol%) of dimethyl 2,2′-azobis (2-methylpropionate) was added to prepare a monomer solution (A-1).

  A 500 ml three-necked flask equipped with a thermometer and a dropping funnel was charged with 50 g of 2-butanone 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 the dropping funnel, the prepared monomer solution (A-1) was added dropwise over 3 hours. The polymerization start time was set as the polymerization start time, and after 6 hours of polymerization reaction, the polymerization solution was cooled to 30 ° C. or less by water cooling. After cooling, the polymerization solution was put into 1000 g of hexane, and the precipitated white powder was collected by filtration. The white powder collected by filtration was redissolved in 200 g of 2-butanone, this 2-butanone solution was added to 1000 g of hexane, and the precipitated white powder was collected by filtration and washed. The same washing operation was performed once again. Thereafter, the white powder obtained by filtration was dried at 50 ° C. for 17 hours to obtain 38.0 g of a white powder copolymer (yield 76.0%). This copolymer was designated as a polymer (A-1).

The polymer (A-1) has Mw of 7500 and Mw / Mn of 1.46. As a result of ¹³ C-NMR analysis, the monomer (M3-1), the monomer (M2-1), and The content ratio (mol%) of each repeating unit derived from the monomer (M1-1) was 51.9: 48.0: 0.1.

(Synthesis Example 2) Synthesis of Polymer (A-2):
Monomer (M3-1) 32.59 g (60 mol%), monomer (M2-1) 15.10 g (35 mol%), monomer represented by the formula (M1-2) (M1) -2) 2.31 g (5 mol%) was dissolved in 180 g of 2-butanone, and 1.90 g (5 mol%) of dimethyl 2,2′-azobis (2-methylpropionate) was added as an initiator. Except that the monomer solution (A-2) was prepared, 37.4 g of the polymer (A-2) was obtained in the same manner as in Synthesis Example 1 (yield 74.8%).

The polymer (A-2) has Mw of 7600 and Mw / Mn of 1.47. As a result of ¹³ C-NMR analysis, the monomer (M3-1), the monomer (M2-1), and The content ratio (mol%) of each repeating unit derived from the monomer (M1-2) was 52.3: 43.6: 4.1.

(Synthesis Example 3) Synthesis of Polymer (A-3):
Monomer (M3-1) 32.69 g (60 mol%) and monomer (M2-1) 17.31 g (40 mol%) were dissolved in 180 g of 2-butanone, and dimethyl 2,2 was used as an initiator. A polymer (A-) was prepared in the same manner as in Synthesis Example 1 except that 1.91 g (5 mol%) of '-azobis (2-methylpropionate) was added to prepare a monomer solution (A-3). 36.9g of 3) was obtained (yield 73.8%).

The polymer (A-3) has Mw of 7580 and Mw / Mn of 1.46. As a result of ¹³ C-NMR analysis, the monomer (M3-1) and the monomer (M2-1) The content rate (mol%) of each derived repeating unit was 55.5: 44.5.

(Synthesis Example 4) Synthesis of Polymer (A-4):
27.19 g (50 mol%) of monomer (M3-1), 10.97 g (20 mol%) of monomer (M4-1) represented by formula (M4-1), and formula (M5- 1) 11.81 g (29.9 mol%) of the monomer (M5-1) represented by 1) and 0.04 g (0.1 mol%) of the monomer (M1-1) were converted into 100 g of 2-butanone. Example of synthesis except that 1.91 g (5 mol%) of dimethyl 2,2′-azobis (2-methylpropionate) was added as an initiator to prepare a monomer solution (A-4). In the same manner as in Example 1, 40.1 g of the polymer (A-4) was obtained (yield: 80.2%).

The polymer (A-4) has Mw of 7400 and Mw / Mn of 1.41, and as a result of ¹³ C-NMR analysis, the monomer (M3-1), monomer (M4-1), The content ratio (mol%) of each repeating unit derived from the monomer (M5-1) and the monomer (M1-1) was 44.2: 34.4: 21.3: 0.1. .

Example 1
As shown in Table 1 below, the acid generator (B-1) (triphenylsulfonium nonafluorobutanesulfonate) 7.5 is used as the acid generator (B) with respect to 100 parts by mass of the polymer (A-1). Parts, and solvent (C), solvent (C-1) (propylene glycol monomethyl ether acetate) 1500 parts, solvent (C-2) (cyclohexanone) 650 parts, and solvent (C-3) (γ-butyrolactone) 30 Were mixed and filtered through a filter having a pore diameter of 200 nm to obtain a radiation sensitive resin composition (Example 1). The obtained radiation-sensitive resin composition (Example 1) was subjected to various evaluations. As a result, the sensitivity was 43.7 (mJ / cm ² ) and the LWR was “good”. These results are shown in Table 2.

(Example 2)
As shown in Table 1 below, Example 1 was used except that 2 parts by mass of the polymer (A-2) and 98 parts by mass of the polymer (A-3) (100 parts by mass in total) were used as the polymer components. In the same manner as described above, a radiation sensitive resin composition (Example 2) was obtained. The obtained radiation-sensitive resin composition (Example 2) was subjected to various evaluations. As a result, the sensitivity was 44.9 (mJ / cm ² ) and the LWR was “good”. These results are shown in Table 2.

(Comparative Example 1)
As shown in Table 1 below, the radiation-sensitive resin composition (Example 2) was prepared in the same manner as in Example 1 except that 100 parts by mass of the polymer (A-4) was used as the polymer component. Obtained. The obtained radiation-sensitive resin composition (Example 2) was subjected to various evaluations. As a result, the sensitivity was 41.5 (mJ / cm ² ) and the LWR was “bad”. These results are shown in Table 2.

  From the results of Tables 1 and 2, the resist material containing a repeating unit having a cyclic carbonate structure together with a repeating unit having a nitrogen-containing compound structure is excellent not only in sensitivity but also in LWR performance. it is obvious.

  The radiation-sensitive resin composition of the present invention is suitable as a material for a chemically amplified resist used in a photolithography process using immersion exposure, and manufactures semiconductor devices that are expected to be further miniaturized in the future. Therefore, it is extremely useful as a resist material.

Claims (8)

A polymer component (A) comprising one or two or more polymers, a radiation sensitive acid generator (B), and a solvent (C),
The radiation sensitive resin composition in which the polymer component (A) contains a repeating unit (a1) represented by the following general formula (a1) and a repeating unit (a2) represented by the following general formula (a2).

(In the general formulas (a1) and (a2), each R ¹ independently represents a hydrogen atom or a methyl group. In the general formula (a1), R ² is a straight chain having 1 to 3 carbon atoms. Each of the two R ³ independently represents a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 5 carbon atoms, or two R ³ R ³ may be bonded to each other to form a 4- to 10-membered heterocyclic structure together with the nitrogen atom to which both are bonded, and in the general formula (a2), R ⁴ is a single bond, Or a linear, branched, or cyclic divalent hydrocarbon group having 1 to 10 carbon atoms, and A ¹ represents a trivalent organic group.)   The radiation sensitive resin composition according to claim 1, wherein at least one of the polymers contained in the polymer component (A) is a copolymer having the repeating unit (a1) and the repeating unit (a2). .   The sensation according to claim 1, wherein at least two of the polymers contained in the polymer component (A) are a polymer having the repeating unit (a1) and a polymer having the repeating unit (a2). Radiation resin composition. The repeating unit (a1) is at least one of the repeating unit (a1-A) represented by the following general formula (a1-A) and the repeating unit (a1-B) represented by the following general formula (a1-B). The radiation sensitive resin composition according to any one of claims 1 to 3.

(In the general formulas (a1-A) and (a1-B), each R ¹ independently represents a hydrogen atom or a methyl group, and each l independently represents an integer of 1 to 3. In the formula (a1-A), each m independently represents an integer of 1 to ^{3. In the} general formula (a1-B), A ² represents an oxygen atom or an amino group, and n is 1 or 2 is shown.)   The feeling as described in any one of Claims 1-4 whose content rate of the said repeating unit (a1) is 0.01-20 mol% with respect to the sum total of all the repeating units of the said polymer component (A). Radiation resin composition.   The content ratio of the said repeating unit (a2) is 5-80 mol% with respect to the sum total of all the repeating units of the said polymer component (A), The radiation sensitivity as described in any one of Claims 1-5. Resin composition. The radiation sensitive resin composition as described in any one of Claims 1-6 in which the said polymer component (A) further contains the repeating unit (a3) represented by the following general formula (a3).

(In the general formula (a3), R ¹ represents a hydrogen atom or a methyl group, and three R ^{5 s} each independently represent a linear or branched alkyl group having 1 to 4 carbon atoms, or a carbon number. or showing 4-20 alicyclic hydrocarbon group, or three of R ^5, cycloaliphatic having 4 to 20 carbon atoms with 2 carbon atoms contained in R ⁵ are bonded each other are bonded to each other (Formula hydrocarbon group may be formed, and the remaining one R ⁵ may represent a linear or branched alkyl group having 1 to 4 carbon atoms.)   The radiation sensitive resin composition as described in any one of Claims 1-7 in which the said polymer component (A) further contains the repeating unit (a4) which has a lactone skeleton.