JP5353434B2 - Radiation sensitive resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation-sensitive resin composition having good sensitivity and the like. <P>SOLUTION: The radiation-sensitive resin composition includes an acid dissociable group-containing resin, a radiation-sensitive acid generator expressed by general formula of M<SP>+</SP>Z<SP>-</SP>(where M<SP>+</SP>represents an onium cation and Z<SP>-</SP>represents an anion expressed by general formula (1-1) or (1-2)), and a compound expressed by general formula (c1). In the formulae, R<SP>1</SP>to R<SP>5</SP>each represents an alkyl group having 1 to 20 carbon atoms with substitution of a fluorine atom, or the like; A represents a single bond or the like; and R<SP>6</SP>and R<SP>7</SP>each represents a hydrocarbon group having 1 to 25 carbon atoms, or the like. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

The present invention relates to a radiation sensitive resin composition. More specifically, the present invention relates to various types of radiation such as KrF excimer laser, ArF excimer laser, F ₂ excimer laser, EUV and other (extreme) far ultraviolet rays, synchrotron radiation and other X-rays, and electron beam charged particle beams. The present invention relates to a radiation-sensitive resin composition used as a chemically amplified resist suitable for microfabrication.

  Conventionally, in a manufacturing process of a semiconductor device such as an IC or LSI, fine processing by lithography using a photoresist composition has been performed. In recent years, with the high integration of integrated circuits, the formation of ultrafine patterns in the submicron region and the quarter micron region has been required. In response to such a demand, shortening of the exposure wavelength has been studied. Specifically, g-line is conventionally used as the exposure wavelength, but i-line, KrF excimer laser light, ArF excimer laser light, and the like have been used as the exposure wavelength. At present, the development of lithography using electron beams, X-rays, or EUV light in addition to excimer laser light is in progress.

  Lithography using EUV light is expected as a next-generation or next-generation pattern formation technology, and EUV light can be used as an exposure wavelength, and development of a positive resist with high sensitivity and high resolution is desired. ing.

  Increasing the sensitivity of a positive resist is a very important issue in order to reduce the wafer processing time. However, in an EUV positive resist, if an attempt is made to achieve high sensitivity, in addition to a reduction in resolution, nano edge roughness is deteriorated. Therefore, development of a resist that satisfies all these characteristics is eagerly desired.

  Nano edge roughness means that the resist pattern and the edge of the substrate interface vary irregularly in the direction perpendicular to the direction in which the line portion extends due to the characteristics of the resist. It is a deviation that sometimes occurs (ie, the difference between the design dimension and the actual pattern dimension).

  When this deviation occurs, the deviation is simultaneously transferred in the etching process (transfer process) using the resist as a mask. And since such a shift | offset | difference deteriorates an electrical property, if the frequency of generation | occurrence | production of a shift | offset | difference is high, a yield will be reduced. In particular, since EUV light is used in lithography in an ultrafine region of 32 nm or less, even a slight deviation causes deterioration of electrical characteristics. Therefore, improving the nano edge roughness is an extremely important issue.

  Here, as described above, increasing sensitivity and improving nanoedge roughness (that is, obtaining a good pattern shape) are in a trade-off relationship, and do all of the above performances in such a relationship be satisfied? This is a very important issue.

  Therefore, in order to solve the above-mentioned problem, in order to achieve particularly high sensitivity, it has been reported that an acid generating agent that generates an acid is blended using an acid generated from a radiation-sensitive acid generator as a catalyst ( For example, see Patent Document 1 or 2.)

JP 2000-35665 A JP 2008-96743 A

  However, even the radiation-sensitive resin composition described in Patent Document 1 or 2 has a problem that the sensitivity is still insufficient and the wafer processing time is long.

  The present invention has been made to solve the above-described problems of the prior art, and in addition to having good sensitivity (ie, short wafer processing time), it is possible to form a resist film with excellent resolution. And an object of the present invention is to provide a radiation-sensitive resin composition capable of forming a resist pattern excellent in nano edge roughness.

  The present invention provides the following radiation-sensitive resin composition.

[1] (A) a resin containing a repeating unit having an acid dissociable group, (B) a radiation sensitive acid generator represented by the following general formula (b1), and (C) the following general formula (c1) A radiation-sensitive resin composition comprising: a compound represented by:
M ⁺ Z ⁻ (b1)
(In the general formula (b1), M ⁺ is a monovalent onium cation, and Z ⁻ is a monovalent anion represented by the following general formula (1-1) or (1-2).)

（前記一般式（１−１）中、Ｒ^１及びＲ^２は、相互に独立に、少なくとも１つのフッ素原子で置換された炭素数１〜２０のアルキル基であるか、或いは、Ｒ^１及びＲ^２が相互に結合して、少なくとも１つのフッ素原子で置換された炭素数１〜２０の環状構造を形成している。前記一般式（１−２）中、Ｒ^３、Ｒ^４、及びＲ^５は、相互に独立に、少なくとも１つのフッ素原子で置換された炭素数１〜２０のアルキル基であるか、或いは、Ｒ^３、Ｒ^４、及びＲ^５のいずれか２つが相互に結合して、少なくとも１つのフッ素原子で置換された炭素数１〜２０の環状構造を形成しており、残りの１つが、少なくとも１つのフッ素原子で置換された炭素数１〜２０のアルキル基である。）

(In the general formula (1-1), R ¹ and R ² are each independently an alkyl group having 1 to 20 carbon atoms substituted with at least one fluorine atom, or R ¹ and R 2. ² are bonded to each other to form a cyclic structure having 1 to 20 carbon atoms that is substituted with at least one fluorine atom, wherein R ³ , R ⁴ , and R ^{5 in the} general formula (1-2). Are each independently an alkyl group having 1 to 20 carbon atoms substituted with at least one fluorine atom, or any two of R ³ , R ⁴ and R ⁵ are bonded to each other, A cyclic structure having 1 to 20 carbon atoms substituted with at least one fluorine atom is formed, and the remaining one is an alkyl group having 1 to 20 carbon atoms substituted with at least one fluorine atom.)

（前記一般式（ｃ１）中、Ａは、単結合、下記式（２−１）、下記式（２−２）、または下記式（２−３）で表される基である。Ｒ^６は、水素原子、炭素数１〜２５の炭化水素基である。Ｒ^７は、フッ素原子で置換されていてもよい炭素数１〜２５の炭化水素基である。）

In (Formula (c1), A is a single bond, the following formulas (2-1), a is .R ⁶ is a group represented by the following formula (2-2), or the following formula (2-3) , A hydrogen atom, a hydrocarbon group having 1 to 25 carbon atoms, and R ⁷ is a hydrocarbon group having 1 to 25 carbon atoms which may be substituted with a fluorine atom.)

[2] The radiation-sensitive resin composition according to [1], wherein the compound represented by the general formula (c1) is a compound represented by the following general formula (c1-1).

（前記一般式（ｃ１−１）中、Ｒ^７は、フッ素原子で置換されていてもよい炭素数１〜２５の炭化水素基である。）

(In said general formula (c1-1), R < ⁷ > is a C1-C25 hydrocarbon group which may be substituted by the fluorine atom.)

[3] The radiation sensitive resin composition according to [1], wherein M ⁺ in the general formula (b1) is a sulfonium cation or an iodonium cation.

[4] The repeating unit having the acid dissociable group contained in the resin (A) is represented by the following general formula (a-1) and the following general formula (a-2). The radiation-sensitive resin composition according to any one of [1] to [3], which is at least one of the repeating units.

（前記一般式（ａ−１）中、Ｒ^８は、水素原子、メチル基、トリフルオロメチル基、またはヒドロキシメチル基である。各Ｒ^９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、または炭素数１〜４の直鎖状若しくは分岐状のアルキル基であるか、或いは、いずれか２つのＲ^９が相互に結合して、それぞれが結合している炭素原子とともに２価の脂環式炭化水素基またはその誘導体を形成しており、残りの１つが、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、または炭素数１〜４の直鎖状若しくは分岐状のアルキル基である。）

(In said general formula (a-1), R < ⁸ > is a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group. Each R < ⁹ > is C1-C20 1 independently of each other. whether the valence of the alicyclic hydrocarbon group or a derivative thereof or a linear or branched alkyl group having 1 to 4 carbon atoms, or any two of R ⁹ are bonded to each other, each bond A divalent alicyclic hydrocarbon group or a derivative thereof together with the carbon atom in which the carbon atom is bonded, and the remaining one is a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or carbon (It is a linear or branched alkyl group of formulas 1 to 4.)

（前記一般式（ａ−２）中、Ｒ^１０は、水素原子、メチル基、トリフルオロメチル基、またはヒドロキシメチル基である。各Ｒ^１１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、または炭素数１〜４の直鎖状若しくは分岐状のアルキル基であるか、或いは、いずれか２つのＲ^１１が相互に結合して、それぞれが結合している炭素原子とともに２価の脂環式炭化水素基またはその誘導体を形成しており、残りの１つが、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、または炭素数１〜４の直鎖状若しくは分岐状のアルキル基である。）

(In said general formula (a-2), R < ¹⁰ > is a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group. Each R < ¹¹ > is C1-C20 1 independently of each other. Is a valent alicyclic hydrocarbon group or a derivative thereof, or a linear or branched alkyl group having 1 to 4 carbon atoms, or any two R ¹¹ are bonded to each other, and each is bonded A divalent alicyclic hydrocarbon group or a derivative thereof together with the carbon atom in which the carbon atom is bonded, and the remaining one is a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or carbon (It is a linear or branched alkyl group of formulas 1 to 4.)

[5] The resin (A) is selected from the group consisting of repeating units represented by the following general formula (a-3), the following general formula (a-4), and the following general formula (a-5). The radiation sensitive resin composition according to [4], further containing at least one selected from the group consisting of:

（前記一般式（ａ−３）中、Ｒ^１２は、水素原子またはメチル基であり、Ｒ^１３は、水素原子、炭素数１〜１２の直鎖状若しくは分岐状のアルキル基、または、炭素数１〜１２の直鎖状若しくは分岐状のアルコキシル基である。ｋは０〜３の整数であり、ｌは０〜３の整数である。）

(In the general formula (a-3), R ¹² is a hydrogen atom or a methyl group, and R ¹³ is a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, or a carbon number. 1 to 12 linear or branched alkoxyl groups, k is an integer of 0 to 3, and l is an integer of 0 to 3.)

（前記一般式（ａ−４）中、Ｒ^１４は、水素原子またはメチル基であり、Ｒ^１５は、水素原子、炭素数１〜１２の直鎖状若しくは分岐状のアルキル基、または、炭素数１〜１２の直鎖状若しくは分岐状のアルコキシル基である。ｎは１〜３の整数であり、ｍは０〜３の整数である。）

(In the general formula (a-4), R ¹⁴ is a hydrogen atom or a methyl group, and R ¹⁵ is a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, or a carbon number. A linear or branched alkoxyl group of 1 to 12. n is an integer of 1 to 3, and m is an integer of 0 to 3.)

（前記一般式（ａ−５）中、Ｒ^１６は、水素原子またはメチル基であり、Ｒ^１７は、水素原子、炭素数１〜１２の直鎖状若しくは分岐状のアルキル基、または、炭素数１〜１２の直鎖状若しくは分岐状のアルコキシル基である。ｐは１〜３の整数であり、ｑは０〜３の整数である。）

(In the general formula (a-5), R ¹⁶ is a hydrogen atom or a methyl group, and R ¹⁷ is a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, or a carbon number. 1 to 12 linear or branched alkoxyl groups, p is an integer of 1 to 3, and q is an integer of 0 to 3)

  In addition to having good sensitivity, the radiation-sensitive resin composition of the present invention can form a resist film with excellent resolution, and can produce a resist pattern with excellent nanoedge roughness. Is.

It is a top view which shows a line and space pattern typically. It is sectional drawing which shows typically the A-A 'cross section shown in FIG.

  Hereinafter, although the form for implementing this invention is demonstrated, this invention is not limited to the following embodiment. That is, it is understood that modifications and improvements as appropriate to the following embodiments are also within the scope of the present invention based on ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. Should be.

[1] Radiation sensitive resin composition:
The radiation sensitive resin composition of the present invention comprises (A) a resin containing a repeating unit having an acid dissociable group (hereinafter sometimes referred to as “resin (A)”), and (B) the following general formula (b1). ) Represented by a radiation sensitive acid generator (hereinafter sometimes referred to as “acid generator (B)”) and (C) a compound represented by the following general formula (c1) (hereinafter referred to as “acid growth”). In some cases, it may be referred to as “agent (C)”. According to the radiation sensitive resin composition of the said structure, in addition to having favorable sensitivity, it can form the resist film excellent in the resolution, and can form the resist pattern excellent in nano edge roughness. That is, it is sensitive to X-rays and electron beams such as (extreme) far ultraviolet rays such as KrF excimer laser, ArF excimer laser, EUV, synchrotron radiation, etc., and has excellent sensitivity. Further, it is possible to form a chemically amplified positive resist film capable of forming a fine pattern with high accuracy and stability. If the sensitivity is good, there is an advantage that the wafer processing time may be short.

[1-1] Resin (A):
(A) The resin containing a repeating unit having an acid-dissociable group is a resin that is insoluble in alkali or hardly soluble in alkali, and is easily soluble in alkali by the action of an acid. Here, in the present specification, “alkali insoluble or hardly soluble in alkali” means an alkali development employed when forming a resist pattern from a resist film formed from a radiation-sensitive resin composition containing the resin (A). Under the conditions, when a film having a film thickness of 100 nm using only the resin (A) instead of the resist film is developed, it means that 50% or more of the initial film thickness of the resist film remains after development.

  Since the radiation sensitive resin composition of the present invention contains such a resin (A), it is sensitive to an electron beam or extreme ultraviolet rays in a lithography process, and a fine pattern is highly accurate and stable. A chemically amplified positive resist film that can be formed in this manner can be formed.

  The repeating unit having an acid dissociable group in the resin (A) is one in which the acid dissociable group is dissociated by the action of an acid. The repeating unit is not particularly limited as long as it has the above action, but may be represented by a repeating unit represented by the following general formula (a-1) (hereinafter referred to as “repeating unit (a-1)”). ) And at least one of repeating units represented by the following general formula (a-2) (hereinafter sometimes referred to as “repeating unit (a-2)”). By using at least one of the repeating unit (a-1) and the repeating unit (a-2) as the repeating unit having an acid dissociable group, there is an advantage that a resist pattern having good sensitivity can be formed. is there.

（上記一般式（ａ−１）中、Ｒ^８は、水素原子、メチル基、トリフルオロメチル基、またはヒドロキシメチル基である。各Ｒ^９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、または炭素数１〜４の直鎖状若しくは分岐状のアルキル基であるか、或いは、いずれか２つのＲ^９が相互に結合して、それぞれが結合している炭素原子とともに２価の脂環式炭化水素基またはその誘導体を形成しており、残りの１つが、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、または炭素数１〜４の直鎖状若しくは分岐状のアルキル基である。）

(In the general formula (a-1), R ⁸ is a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group. Each R ⁹ is independently 1 to 4 carbon atoms. whether the valence of the alicyclic hydrocarbon group or a derivative thereof or a linear or branched alkyl group having 1 to 4 carbon atoms, or any two of R ⁹ are bonded to each other, each bond A divalent alicyclic hydrocarbon group or a derivative thereof together with the carbon atom in which the carbon atom is bonded, and the remaining one is a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or carbon (It is a linear or branched alkyl group of formulas 1 to 4.)

（上記一般式（ａ−２）中、Ｒ^１０は、水素原子、メチル基、トリフルオロメチル基、またはヒドロキシメチル基である。各Ｒ^１１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、または炭素数１〜４の直鎖状若しくは分岐状のアルキル基であるか、或いは、いずれか２つのＲ^１１が相互に結合して、それぞれが結合している炭素原子とともに２価の脂環式炭化水素基またはその誘導体を形成しており、残りの１つが、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、または炭素数１〜４の直鎖状若しくは分岐状のアルキル基である。）

(In the above general formula (a-2), R ¹⁰ is a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group. Each R ¹¹ is independently 1 to 4 carbon atoms. Is a valent alicyclic hydrocarbon group or a derivative thereof, or a linear or branched alkyl group having 1 to 4 carbon atoms, or any two R ¹¹ are bonded to each other, and each is bonded A divalent alicyclic hydrocarbon group or a derivative thereof together with the carbon atom in which the carbon atom is bonded, and the remaining one is a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or carbon (It is a linear or branched alkyl group of formulas 1 to 4.)

Examples of the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms of R ^{9 in} the general formula (a-1) include norbornane, tricyclodecane, tetracyclododecane, adamantane, cyclobutane, cyclopentane, and cyclohexane. A group composed of an alicyclic ring derived from cycloalkanes such as cycloheptane and cyclooctane; a group composed of these alicyclic rings is, for example, a methyl group, an ethyl group, an n-propyl group, an i-propyl group; 1 or more or 1 or more of linear, branched or cyclic alkyl groups having 1 to 4 carbon atoms such as a group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group And the like can be mentioned.

Examples of the linear or branched alkyl group having 1 to 4 carbon atoms of R ^{9 in} the general formula (a-1) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and n-butyl. Group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group and the like.

Examples of the divalent alicyclic hydrocarbon group formed by bonding any two R ⁹ together with the carbon atom to which each R ⁹ is bonded or a derivative thereof include, for example, norbornane, tricyclodecane, tetracyclo Examples include a group consisting of an alicyclic ring derived from dodecane, adamantane, cyclopentane or cyclohexane, a group obtained by substituting a group consisting of these alicyclic rings with the above alkyl group, and the like.

Next, as monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms of R ¹¹ in general formula (a-2), 1 of 4 to 20 carbon atoms in R ⁹ of general formula (a-1) is used. The thing similar to a valent alicyclic hydrocarbon group can be illustrated. Moreover, as a C1-C4 linear or branched alkyl group of R < ¹¹ > of General formula (a-2), C1-C4 linear of R < ⁹ > of General formula (a-1). Examples thereof are the same as the linear or branched alkyl groups. Additionally, any two of R ¹¹ are bonded to each other, the divalent alicyclic hydrocarbon group or a derivative thereof formed with the carbon atom to which each is attached, any two of R ⁹ mutual And the same divalent alicyclic hydrocarbon groups or derivatives thereof formed together with the carbon atoms to which they are bonded.

  Among the repeating units represented by the general formula (a-1), the repeating units represented by the following general formulas (a-1-1) to (a-1-7) are preferable, and the following general formula (a-1) -2), the repeating unit represented by (a-1-3) or (a-1-4) is more preferable. These repeating units have an advantage that a resist pattern excellent in nano edge roughness can be formed.

（上記一般式（ａ−１−１）〜（ａ−１−７）中、Ｒ^１８は、相互に独立に、水素原子、メチル基、トリフルオロメチル基、またはヒドロキシメチル基であり、Ｒ^１９は、相互に独立に、炭素数１〜４の直鎖状または分岐状のアルキル基である。）

(In the general formulas (a-1-1) ~ (a -1-7), R 18 are independently of each other hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl ^{group,, R 19} Are each independently a linear or branched alkyl group having 1 to 4 carbon atoms.)

  Moreover, among the repeating units represented by the general formula (a-2), the repeating units represented by the following general formula (a-2-1) are preferable. Such a repeating unit has an advantage that a resist pattern excellent in nano edge roughness can be formed.

（上記一般式（ａ−２−１）中、Ｒ^２０は、水素原子、メチル基、トリフルオロメチル基、またはヒドロキシメチル基であり、Ｒ^２１は、相互に独立に、炭素数１〜４の直鎖状または分岐状のアルキル基である。）

(In the above general formula (a-2-1), R ²⁰ is a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group, and R ²¹ are independently of one another having 1 to 4 carbon atoms. (It is a linear or branched alkyl group.)

  In addition, resin (A) can use said each repeating unit individually by 1 type or in combination of 2 or more types.

  In addition to at least one of the repeating unit represented by the general formula (a-1) and the repeating unit represented by the general formula (a-2), the resin (A) is represented by the following general formula (a-3), It is preferable to further contain at least one selected from the group consisting of repeating units represented by the following general formula (a-4) and the following general formula (a-5).

（上記一般式（ａ−３）中、Ｒ^１２は、水素原子またはメチル基であり、Ｒ^１３は、水素原子、炭素数１〜１２の直鎖状若しくは分岐状のアルキル基、または、炭素数１〜１２の直鎖状若しくは分岐状のアルコキシル基である。ｋは０〜３の整数であり、ｌは０〜３の整数である。）

(In the general formula (a-3), R ¹² is a hydrogen atom or a methyl group, and R ¹³ is a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, or a carbon number. 1 to 12 linear or branched alkoxyl groups, k is an integer of 0 to 3, and l is an integer of 0 to 3.)

（上記一般式（ａ−４）中、Ｒ^１４は、水素原子またはメチル基であり、Ｒ^１５は、水素原子、炭素数１〜１２の直鎖状若しくは分岐状のアルキル基、または、炭素数１〜１２の直鎖状若しくは分岐状のアルコキシル基である。ｎは１〜３の整数であり、ｍは０〜３の整数である。）

(In the general formula (a-4), R ¹⁴ is a hydrogen atom or a methyl group, and R ¹⁵ is a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, or a carbon number. A linear or branched alkoxyl group of 1 to 12. n is an integer of 1 to 3, and m is an integer of 0 to 3.)

（上記一般式（ａ−５）中、Ｒ^１６は、水素原子またはメチル基であり、Ｒ^１７は、水素原子、炭素数１〜１２の直鎖状若しくは分岐状のアルキル基、または、炭素数１〜１２の直鎖状若しくは分岐状のアルコキシル基である。ｐは１〜３の整数であり、ｑは０〜３の整数である。）

(In the general formula (a-5), R ¹⁶ is a hydrogen atom or a methyl group, and R ¹⁷ is a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, or a carbon number. 1 to 12 linear or branched alkoxyl groups, p is an integer of 1 to 3, and q is an integer of 0 to 3)

  By containing a repeating unit represented by the general formula (a-3) (hereinafter sometimes referred to as “repeating unit (a-3)”), a resist pattern having excellent nano edge roughness can be formed. There is an advantage that you can.

Examples of the linear or branched alkyl group having 1 to 12 carbon atoms of R ^{13 in} the general formula (a-3) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and n-butyl. Group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group and the like. Among these, since a resist pattern excellent in nano edge roughness can be formed, a methyl group, an ethyl group, an n-butyl group, and a t-butyl group are preferable.

Examples of the linear or branched alkoxyl group having 1 to 12 carbon atoms of R ^{13 in} the general formula (a-3) include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, and n-butoxy. Group, 2-methylpropoxy group, 1-methylpropoxy group, t-butoxy group and the like. Among these, a methoxy group and an ethoxy group are preferable because a resist pattern excellent in nano edge roughness can be formed.

  K in the general formula (a-3) is an integer of 0 to 3, and preferably 1 or 2. Moreover, l is an integer of 0-3, and it is preferable that it is 0-2.

  Specific examples of the repeating unit (a-3) include repeating units represented by the following formulas (a-3-1) to (a-3-4). In addition, the repeating unit represented by general formula (a-3) can be used individually by 1 type or in combination of 2 or more types.

  The repeating unit represented by formula (a-3) can be obtained by using the corresponding hydroxystyrene derivative as a monomer. Moreover, it can also obtain by using as a monomer the compound from which a hydroxy styrene derivative is obtained by hydrolyzing.

  Examples of the monomer used to generate the repeating unit represented by the general formula (a-3) include p-acetoxystyrene, p- (1-ethoxy) styrene, and p-isopropenylphenol. be able to. In addition, when p-acetoxystyrene is used, the repeating unit represented by Formula (a-3) is produced | generated by performing a hydrolysis reaction of a side chain after a polymerization reaction.

  By containing a repeating unit represented by the general formula (a-4) (hereinafter sometimes referred to as “repeating unit (a-4)”), a resist pattern having excellent nano edge roughness can be formed. There is an advantage that you can.

The linear or branched alkyl group having 1 to 12 carbon atoms and the linear or branched alkoxyl group having 1 to 12 carbon atoms in general formula (a-4) R ¹⁵ are each described above. And R ¹³ of the general formula (a-3) are the same as the linear or branched alkyl group having 1 to 12 carbon atoms and the linear or branched alkoxyl group having 1 to 12 carbon atoms. can do.

  N in the general formula (a-4) is an integer of 1 to 3, and preferably 1 or 2. M is an integer of 0 to 3, and is preferably 0 or 1.

  Specific examples of the repeating unit (a-4) include repeating units represented by the following formulas (a-4-1) and (a-4-2). In addition, the repeating unit represented by general formula (a-4) can be used individually by 1 type or in combination of 2 or more types.

  The repeating unit represented by formula (a-4) can be obtained by using a corresponding monomer. As a monomer used in order to produce | generate the repeating unit represented by general formula (a-4), 4-hydroxyphenyl acrylate, 4-hydroxyphenyl methacrylate, etc. can be mentioned, for example.

  By containing a repeating unit represented by the general formula (a-5) (hereinafter sometimes referred to as “repeating unit (a-5)”), a resist pattern having excellent nanoedge roughness can be formed. There is an advantage that you can.

R ^{17 in} the general formula (a-5) is a linear or branched alkyl group having 1 to 12 carbon atoms and a linear or branched alkoxyl group having 1 to 12 carbon atoms, respectively. The same as the linear or branched alkyl group having 1 to 12 carbon atoms and the linear or branched alkoxyl group having 1 to 12 carbon atoms of R ¹³ in the general formula (a-3) described above Can be illustrated.

  P in the general formula (a-5) is an integer of 1 to 3, and preferably 1 or 2. Q is an integer of 0 to 3, and is preferably 0 or 1.

  Specific examples of the repeating unit (a-5) include repeating units represented by the following formulas (a-5-1) and (a-5-2). In addition, the repeating unit represented by general formula (a-5) can be used individually by 1 type or in combination of 2 or more types.

  The repeating unit represented by formula (a-5) can be obtained by using a corresponding monomer. Examples of the monomer used for generating the repeating unit represented by the general formula (a-5) include N- (4-hydroxyphenyl) acrylamide, N- (4-hydroxyphenyl) methacrylamide and the like. Can be mentioned.

  In addition, resin (A) is a repeating unit derived from a non-acid dissociable compound (hereinafter referred to as “repeating unit (hereinafter referred to as“ repeating unit ”)), in addition to the repeating units represented by the general formulas (a-1) to (a-5) described above. a-6) ”may be further contained. By containing the repeating unit (a-6), there is an advantage that a resist pattern excellent in nano edge roughness can be formed.

  A non-acid dissociable compound is a compound that does not contain a group (acid dissociable group) that can be dissociated by the action of an acid. Examples of the non-acid dissociable compound for generating the repeating unit (a-6) include styrene, α-methylstyrene, 4-methylstyrene, 2-methylstyrene, 3-methylstyrene, isobornyl acrylate, Examples include cyclodecanyl (meth) acrylate, tetracyclododecenyl (meth) acrylate, and a compound represented by the following formula (a-6-1). Among these, styrene, α-methylstyrene, 4-methylstyrene, 2-methylstyrene, 3-methylstyrene, tricyclodecanyl acrylate, and a compound represented by the following formula (a-6-1) are preferable. In addition, a repeating unit (a-6) can be used individually by 1 type or in combination of 2 or more types. Further, “(meth) acrylate” in the present specification means “acrylate” or “methacrylate”.

  The content of the repeating unit (a-1) in the resin (A) is preferably 1 mol% or more with respect to 100 mol% of all repeating units in the resin (A), and is preferably 20 to 70 mol%. More preferably, it is more preferably 20 to 60 mol%. There exists a possibility that nano edge roughness may deteriorate that the said content rate is less than 1 mol%. In addition, when the said content is 20 mol% or more, the resist pattern which exhibits the outstanding nano edge roughness can be formed.

  The content of the repeating unit (a-2) in the resin (A) is preferably 1 mol% or more with respect to 100 mol% of all repeating units in the resin (A), and is 20 to 70 mol%. More preferably, it is more preferably 20 to 60 mol%. There exists a possibility that nano edge roughness may deteriorate that the said content rate is less than 1 mol%. In addition, when the content is 20 mol% or more, a resist pattern with excellent nano edge roughness can be formed.

  The total content of the repeating units (a-3) to (a-5) in the resin (A) is 1 mol% or more with respect to 100 mol% of all the repeating units in the resin (A). Preferably, it is 10-95 mol%, More preferably, it is 40-80 mol%. If the total content is less than 1 mol%, the nano edge roughness may be deteriorated. In addition, when it exceeds 95 mol%, there is a possibility that the nano edge roughness is deteriorated.

  The total content of the repeating units (a-1) to (a-5) in the resin (A) is 10 mol% or more with respect to 100 mol% of all the repeating units in the resin (A). Preferably, it is 40-100 mol%, and it is still more preferable that it is 50-100 mol%. There exists a possibility that nano edge roughness may deteriorate that the sum total of the said content rate is less than 10 mol%. Moreover, when it is 10 mol% or more, the resist pattern of the outstanding nano edge roughness can be formed.

  The content ratio of the repeating unit (a-6) in the resin (A) is preferably 60 mol% or less, based on 100 mol% of all repeating units in the resin (A), and is 0 to 50 mol%. More preferably it is. When the amount is 60 mol% or less, a resist pattern excellent in the balance between the resolution performance and the performance of nanoedge roughness can be formed. Moreover, there exists a possibility that nano edge roughness may deteriorate that the said content rate is more than 60 mol%.

  Although the synthesis method of resin (A) is not specifically limited, For example, it can obtain by well-known radical polymerization or anionic polymerization. Further, the side chain hydroxystyrene units in the above-mentioned repeating units (a-3) to (a-5) are obtained by adding a resin such as an acetoxy group in the presence of a base or an acid in an organic solvent. It can be obtained by performing decomposition.

  The radical polymerization is, for example, for generating at least one of the repeating units (a-1) and (a-2) described above in a suitable organic solvent in a nitrogen atmosphere in the presence of a radical polymerization initiator. It can carry out by stirring and heating a monomer and the monomer for producing | generating repeating unit (a-3)-(a-6) as needed.

  Examples of the radical polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobis- (4-methoxy-). 2,4-dimethylvaleronitrile) 2,2′-azobismethylbutyronitrile, 2,2′-azobiscyclohexanecarbonitrile, cyanomethylethylazoformamide, 2,2′-azobis (2,4-dimethylpropion) Acid methyl), azo compounds such as 2,2′-azobiscyanovaleric acid; benzoyl peroxide, lauroyl peroxide, 1,1′-bis- (t-butylperoxy) cyclohexane, 3,5,5-trimethylhexa List organic peroxides such as noyl peroxide, t-butylperoxy-2-ethylhexanoate, hydrogen peroxide, etc. It can be.

  In the polymerization, a polymerization aid such as 2,2,6,6-tetramethyl-1-piperidinyloxy, iodine, mercaptan, or styrene dimer can be added as necessary.

  The reaction temperature in radical polymerization is not particularly limited and can be set as appropriate depending on the type of the initiator, but can be set to, for example, 50 to 200 ° C. In particular, when an azo initiator or a peroxide initiator is used, a temperature at which the half life of the initiator is about 10 minutes to about 30 hours is preferable, and a temperature at which the half life of the initiator is about 30 minutes to about 10 hours. More preferably it is.

  The reaction time varies depending on the type of initiator and the reaction temperature, but the reaction time during which 50% or more of the initiator is consumed is preferred, and in many cases is about 0.5 to 24 hours.

  Anionic polymerization is, for example, a monomer that provides at least one of the above repeating units (a-1) and (a-2) in a suitable organic solvent in a nitrogen atmosphere in the presence of an anionic polymerization initiator. Moreover, it can carry out by stirring the monomer which gives repeating unit (a-3)-(a-6) as needed, and maintaining at predetermined temperature.

  Examples of the anionic polymerization initiator include n-butyl lithium, s-butyl lithium, t-butyl lithium, ethyl lithium, ethyl sodium, 1,1-diphenylhexyl lithium, 1,1-diphenyl-3-methylpentyl lithium, and the like. The organic alkali metal can be mentioned.

  The reaction temperature in the anionic polymerization is not particularly limited, and can be appropriately set depending on the kind of the initiator. In particular, when alkyl lithium is used as an initiator, the temperature is preferably −100 to 50 ° C., and preferably −78 to 30 ° C.

  The reaction time varies depending on the type of initiator and the reaction temperature, but the reaction time during which 50% or more of the initiator is consumed is preferred, and in many cases is about 0.5 to 24 hours.

  In addition, in the synthesis | combination of resin (A), without using a polymerization initiator, it can also superpose | polymerize by heating and can employ | adopt cationic polymerization.

  In addition, when a hydroxystyrene unit is introduced by hydrolyzing the side chain of the resin (A), examples of the acid that can be used for the hydrolysis reaction include p-toluenesulfonic acid and its hydrate, methane Organic acids such as sulfonic acid, trifluoromethanesulfonic acid, malonic acid, oxalic acid, 1,1,1-fluoroacetic acid; inorganic acids such as sulfuric acid, hydrochloric acid, phosphoric acid, hydrobromic acid; pyridinium p-toluenesulfonate, ammonium p -Toluenesulfonate, 4-methylpyridinium p-toluenesulfonate, etc. can be mentioned.

  Examples of the base include inorganic bases such as potassium hydroxide, sodium hydroxide, sodium carbonate, and potassium carbonate; organic bases such as triethylamine, N-methyl-2-pyrrolidone, piperidine, and tetramethylammonium hydroxide. be able to.

  Examples of the organic solvent that can be used for the polymerization and the hydrolysis include ketones such as acetone, methyl ethyl ketone, and methyl amyl ketone; ethers such as diethyl ether and tetrahydrofuran (THF); methanol, ethanol, propanol, and the like. Alcohols; aliphatic hydrocarbons such as hexane, heptane, and octane; aromatic hydrocarbons such as benzene, toluene, and xylene; halogenated alkyls such as chloroform, bromoform, methylene chloride, methylene bromide, and carbon tetrachloride; Esters such as ethyl acetate, butyl acetate, ethyl lactate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cellosolves; dimethylformamide, dimethyl sulfoxide, hexamethylphosphoramide Aprotic polar solvents such like.

  Among these, acetone, methyl amyl ketone, methyl ethyl ketone, tetrahydrofuran, methanol, ethanol, propanol, ethyl acetate, butyl acetate, ethyl lactate, propylene glycol monomethyl ether, and propylene glycol monomethyl ether acetate are preferable.

  The polystyrene-converted weight average molecular weight (hereinafter sometimes referred to as “Mw”) of the resin (A) measured by gel permeation chromatography (GPC) is preferably 3000 to 100,000, and preferably 3000 to 40000. Is more preferable, and it is especially preferable that it is 3000-25000.

  Further, the ratio (Mw / Mn) of the Mw of the resin (A) and the polystyrene-equivalent number average molecular weight (hereinafter sometimes referred to as “Mn”) measured by GPC is preferably 1 to 5, 1 to 3 is more preferable, and 1 to 2.5 is particularly preferable.

[1-2] Acid generator (B):
The acid generator (B) is represented by the following general formula (b1), and is a substance that generates an acid when irradiated with an electron beam, radiation, or the like in a lithography process. The acid generated from the acid generator (B) dissociates the acid-dissociable group in the resin (A) contained in the radiation-sensitive resin composition (that is, releases the protective group), and the resin A part of (A) is alkali-soluble. Since a part of the resin (A) that has become alkali-soluble can be easily removed with an alkali developer or the like, a positive resist pattern can be easily formed.

M ⁺ Z ⁻ (b1)
(In the general formula (b1), M ⁺ is a monovalent onium cation, and Z ⁻ is a monovalent anion represented by the following general formula (1-1) or (1-2).)

（上記一般式（１−１）中、Ｒ^１及びＲ^２は、相互に独立に、少なくとも１つのフッ素原子で置換された炭素数１〜２０のアルキル基であるか、或いは、Ｒ^１及びＲ^２が相互に結合して、少なくとも１つのフッ素原子で置換された炭素数１〜２０の環状構造を形成している。上記一般式（１−２）中、Ｒ^３、Ｒ^４、及びＲ^５は、相互に独立に、少なくとも１つのフッ素原子で置換された炭素数１〜２０のアルキル基であるか、或いは、Ｒ^３、Ｒ^４、及びＲ^５のいずれか２つが相互に結合して、少なくとも１つのフッ素原子で置換された炭素数１〜２０の環状構造を形成しており、残りの１つが、少なくとも１つのフッ素原子で置換された炭素数１〜２０のアルキル基である。）

(In the general formula (1-1), R ¹ and R ² are each independently an alkyl group having 1 to 20 carbon atoms substituted with at least one fluorine atom, or R ¹ and R 2 ² are bonded to each other to form a cyclic structure having 1 to 20 carbon atoms, which is substituted with at least one fluorine atom, wherein R ³ , R ⁴ , and R ^{5 in the} general formula (1-2). Are each independently an alkyl group having 1 to 20 carbon atoms substituted with at least one fluorine atom, or any two of R ³ , R ⁴ and R ⁵ are bonded to each other, A cyclic structure having 1 to 20 carbon atoms substituted with at least one fluorine atom is formed, and the remaining one is an alkyl group having 1 to 20 carbon atoms substituted with at least one fluorine atom.)

M ⁺ in the general formula (b1) is not particularly limited as long as it is a monovalent onium cation. For example, onium cations such as O, S, Se, N, P, As, Sb, Cl, Br, and I Can be mentioned. Among these, in order to obtain better sensitivity, onium cations of S and I, that is, sulfonium cations or iodonium cations are preferable.

Specific examples of the monovalent onium cation represented by M ⁺ include those represented by the following general formulas (3) and (4).

In General Formula (3), R ²² , R ²³ , and R ²⁴ are each independently a linear or branched alkyl group having 1 to 10 carbon atoms that may be substituted, or are substituted. Or an aryl group having 6 to 18 carbon atoms, or any two of R ²² , R ²³ , and R ²⁴ are bonded to each other to form a cyclic structure together with the sulfur atom in the formula, and the rest Is a linear or branched alkyl group having 1 to 10 carbon atoms which may be substituted, or an aryl group having 6 to 18 carbon atoms which may be substituted.

In General Formula (4), R ²⁵ and R ²⁶ are each independently a linear or branched alkyl group having 1 to 10 carbon atoms which may be substituted, or an optionally substituted carbon number. 6 to 18 aryl groups, or R ²⁵ and R ²⁶ are bonded to each other to form a cyclic structure together with the iodine atom in the formula.

The monovalent onium cation moiety represented by M ⁺ is described in, for example, Advances in Polymer Sciences, Vol. 62, p. 1-48 (1984). Specific examples of the monovalent onium cation include a sulfonium cation represented by the following formulas (5-1) to (5-71) and an iodonium cation represented by the following formulas (6-1) to (6-41). Etc.

  Among the monovalent onium cations described above, Formula (5-1), Formula (5-2), Formula (5-6), Formula (5-8), Formula (5-13), Formula (5-19) ), Formula (5-25), formula (5-27), formula (5-29), formula (5-30), formula (5-31), formula (5-51), formula (5-54) Formula (5-62), Formula (5-63), Formula (5-64), Formula (5-65), Formula (5-66), Formula (5-67), Formula (5-68), Formula (5-69), formula (5-70), sulfonium cation represented by formula (5-71); formula (6-1), formula (6-11), formula (6-40), formula (6) The iodonium cation represented by -41) is preferable, and these cations are preferable because they have good sensitivity.

Z ⁻ is a monovalent anion represented by the general formula (1-1) or (1-2), and R ^{1 to} R ^{5 in the} general formula (1-1) or (1-2). Examples of the alkyl group having 1 to 20 carbon atoms substituted with at least one fluorine atom include trifluoromethyl group, difluoroethyl group, nanofluorobutyl group, tetrafluoroethylene group, hexafluoropropylene group, octafluoro A butylene group can be exemplified.

  Specific examples of the acid generator (B) include compounds represented by the following formulas (7-1) to (7-9). Among these, in order to obtain good nano edge roughness, the formulas (7-1), (7-2), (7-4), (7-5), (7-6), (7-7) ) Is preferred.

  The content of the acid generator (B) is preferably 0.1 to 40 parts by mass and more preferably 0.5 to 30 parts by mass with respect to 100 parts by mass of the resin (A). There exists a possibility that a sensitivity and developability may fall that the said content is less than 0.1 mass part. On the other hand, if it exceeds 40 parts by mass, transparency to radiation, pattern shape, heat resistance and the like may be reduced.

[1-3] Acid proliferating agent (C):
The acid proliferating agent (C) is a compound represented by the general formula (c1), and is a compound that generates an acid in a chain reaction by the action of an acid. In other words, the acid proliferating agent (C) is decomposed by the action of the primary (present) acid, and secondarily generates more acid than the temporarily generated acid. As a compound capable of generating more acid (more than the temporarily generated acid described above).

  The radiation-sensitive resin composition of the present invention contains the acid proliferating agent (C), so that a large amount of acid is present over the entire portion (exposed portion) irradiated with radiation in the formed resist film. Occur. Thus, when an acid generate | occur | produces in large quantities in an exposed part, the acid dissociable group of resin (A) in an exposed part will dissociate uniformly. Therefore, the formed resist film can form a resist pattern excellent in nano edge roughness.

  The radiation-sensitive resin composition of the present invention contains a predetermined acid generator (B) and an acid multiplier (C) described above, thereby forming a resist film having excellent sensitivity in combination with these actions. Can be formed. Furthermore, it is possible to form a resist film with excellent resolution. Therefore, a resist pattern excellent in nano edge roughness can be formed.

（上記一般式（ｃ１）中、Ａは、単結合、下記式（２−１）、下記式（２−２）、または下記式（２−３）で表される基である。Ｒ^６は、水素原子、炭素数１〜２５の炭化水素基である。Ｒ^７は、フッ素原子で置換されていてもよい炭素数１〜２５の炭化水素基である。）

In (the above general formula (c1), A is a single bond, the following formulas (2-1), a is .R ⁶ is a group represented by the following formula (2-2), or the following formula (2-3) , A hydrogen atom, a hydrocarbon group having 1 to 25 carbon atoms, and R ⁷ is a hydrocarbon group having 1 to 25 carbon atoms which may be substituted with a fluorine atom.)

  In general formula (c1), as described above, A is a single bond, a group represented by formula (2-1), formula (2-2), or formula (2-3), and is even better. In order to obtain sensitivity (that is, the acid proliferating agent (C) is easily decomposed by the action of an acid), a single bond or a group represented by the general formula (2-1) is preferable, and is a single bond. More preferably.

As described above, R ⁶ in the general formula (c1) is a hydrogen atom or a hydrocarbon group having 1 to 25 carbon atoms, and is preferably a hydrogen atom in order to obtain better sensitivity.

Examples of the hydrocarbon group having 1 to 25 carbon atoms of R ^{6 in} the general formula (c1) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, and a 2-methylpropyl group. A linear or branched alkyl group having 1 to 12 carbon atoms such as 1-methylpropyl group and t-butyl group; methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n-butoxy group And linear or branched alkoxyl groups having 1 to 12 carbon atoms such as 2-methylpropoxy group, 1-methylpropoxy group and t-butoxy group. Among these, in order to obtain better sensitivity, a hydrogen atom, a methyl group, an ethyl group, an n-butyl group, and a t-butyl group are preferable, and a hydrogen atom and a t-butyl group are preferable.

The hydrocarbon group of the general formula (c1) in R ⁷ fluorine atoms good 25 carbon atoms optionally substituted by, may be mentioned aliphatic group, an aromatic group, a heterocyclic group. Examples of the aliphatic group include a chain or cyclic (including bridged carbocyclic) alkyl group, a chain or cyclic (including bridged carbocyclic) alkenyl group, and the like. The aliphatic group preferably has 1 to 12 carbon atoms, and more preferably 1 to 8 carbon atoms. The aromatic group may be a monocyclic structure or a polycyclic structure, and specific examples include an aryl group and an arylalkyl group.

  Specific examples of the aliphatic group and the aromatic group include, for example, a methyl group, an ethyl group, a propyl group, a butyl group, an acyl group, a hexyl group, a vinyl group, a propyl group, an aryl group, a cyclohexyl group, a cyclooctyl group, and a bicyclo group. Examples thereof include a hydrocarbon group, a tricyclohydrocarbon group, a phenyl group, a tolyl group, a benzyl group, a phenethyl group, a naphthyl group, a naphthylmethyl group, and substituted products thereof. Examples of the substituent include a trifluoromethyl group and a nonafluorobutyl group.

  The heterocyclic group may be a monocyclic structure or a polycyclic structure, and examples thereof include those derived from various conventionally known heterocyclic compounds. Specifically, monovalent groups derived from various heterocyclic compounds, for example, five-membered ring compounds containing one heteroatom such as furan, pyrrole, benzofuran, indole, carbazole and the like, condensed ring compounds thereof, oxazole, pyrazole 5-membered ring compounds containing two heteroatoms such as, and condensed ring compounds thereof, pyran, pyrone, coumarin, pyridine, quinoline, isoquinoline, acridine, etc., six-membered ring compounds and condensed ring compounds thereof, pyridazine , Pyrimidine, pyrazine, phthalazine and the like, and six-membered ring compounds containing two heteroatoms and condensed ring compounds thereof.

  The acid proliferating agent (C) can be synthesized by reacting a diol compound with a halide of sulfonic acid. The diol compound has two isomers, cis and trans. The cis isomer can be preferably used because it is more thermally stable. The acid proliferating agent (C) can be stably stored as long as no acid is present.

  The compound represented by the general formula (c1) (acid proliferating agent (C)) is preferably a compound represented by the general formula (c1-1) described above. With such a compound, particularly good sensitivity can be obtained. There is also an advantage that it is thermally stable.

  Specific examples of the acid proliferating agent (C) include compounds represented by the following formulas (8-1) to (8-11). Among these, in order to obtain better sensitivity, the formulas (8-1), (8-4), (8-8), (8-9), (8-10), (8-11) The compound represented by these is preferable.

  The content of the acid proliferating agent (C) is preferably 30 parts by mass or less, more preferably 5 to 25 parts by mass, and 5 to 20 parts by mass with respect to 100 parts by mass of the resin (A). It is particularly preferred. There exists a possibility that the sensitivity of the formed resist film and the developability of an exposure part may fall that the said content is more than 30 mass parts. In addition, when it is less than 5 mass parts, there exists a possibility that a sensitivity may not fully be improved.

[1-4] Acid diffusion controller (D):
The radiation sensitive resin composition of the present invention preferably further contains an acid diffusion controller (D). The acid diffusion controller (D) is a component having an action of controlling a diffusion phenomenon in the resist film of an acid generated from the acid generator (B) by exposure and suppressing an undesirable chemical reaction in a non-exposed region.

  By containing such an acid diffusion controller (D), the storage stability of the resulting radiation-sensitive resin composition is improved. In addition, the resolution of the formed resist film is further improved, and changes in the line width of the resist pattern due to fluctuations in the holding time (PED) after exposure until heat treatment can be suppressed, thereby improving process stability. An extremely excellent radiation sensitive resin composition can be obtained.

  Examples of the acid diffusion controller (D) include nitrogen-containing organic compounds and photosensitive basic compounds.

  Examples of the nitrogen-containing organic compound include a compound represented by the following general formula (9) (hereinafter referred to as “nitrogen-containing compound (i)”), a compound having two nitrogen atoms in the same molecule (hereinafter referred to as “ Nitrogen-containing compound (ii) ”), polyamino compounds and polymers having three or more nitrogen atoms (hereinafter collectively referred to as“ nitrogen-containing compound (iii) ”), amide group-containing compounds, urea compounds, nitrogen-containing compounds Examples include heterocyclic compounds.

In the general formula (9), R ²⁷ are independently of each other a hydrogen atom, an optionally substituted linear, branched or cyclic alkyl group, an optionally substituted aryl group, or a substituted group. An aralkyl group that may be used.

  Examples of the nitrogen-containing compound (i) include mono (cyclo) alkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, cyclohexylamine; di-n- Butylamine, di-n-pentylamine, di-n-hexylamine, di-n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine, cyclohexylmethylamine, dicyclohexylamine, etc. Di (cyclo) alkylamines;

  Triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri -Tri (cyclo) alkylamines such as n-decylamine, cyclohexyldimethylamine, methyldicyclohexylamine, and tricyclohexylamine; substituted alkylamines such as triethanolamine; aniline, N-methylaniline, N, N-dimethylaniline, 2 -Methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, triphenylamine, naphthylamine, 2,4,6-tri-tert-butyl-N-methylaniline, N-phenyldiethanolamine, 2 , - and aromatic amine such as diisopropyl aniline.

  Examples of the nitrogen-containing compound (ii) include ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diaminodiphenylmethane, and 4,4′-diaminodiphenylether. 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylamine, 2,2-bis (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 2, -(4-aminophenyl) -2- (3-hydroxyphenyl) propane, 2- (4-aminophenyl) -2- (4-hydroxyphenyl) propane, 1,4-bis [1- (4-aminophenyl) ) -1-methylethyl] benzene, 1,3-bis [1- (4-aminophenyl) -1-methyl ester Benzene], bis (2-dimethylaminoethyl) ether, bis (2-diethylaminoethyl) ether, 1- (2-hydroxyethyl) -2-imidazolidinone, 2-quinoxalinol, N, N, N ′ , N′-tetrakis (2-hydroxypropyl) ethylenediamine, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine and the like.

  Examples of the nitrogen-containing compound (iii) include polyethyleneimine, polyallylamine, 2-dimethylaminoethylacrylamide polymer, and the like.

  Examples of the amide group-containing compound include Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, Nt- Butoxycarbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-2-adamantylamine, Nt-butoxycarbonyl-N-methyl-1-adamantylamine, (S)-( -)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, (R)-(+)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, Nt-butoxycarbonyl-4-hydroxypiperidine Nt-butoxycarbonylpyrrolidine, Nt-butoxycarbonyl Perazine,

  N, N-di-t-butoxycarbonyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-N-methyl-1-adamantylamine, Nt-butoxycarbonyl-4,4′-diaminodiphenylmethane N, N′-di-t-butoxycarbonylhexamethylenediamine, N, N, N ′, N′-tetra-t-butoxycarbonylhexamethylenediamine, N, N′-di-t-butoxycarbonyl-1, 7-diaminoheptane, N, N′-di-t-butoxycarbonyl-1,8-diaminooctane, N, N′-di-t-butoxycarbonyl-1,9-diaminononane, N, N′-di-t -Butoxycarbonyl-1,10-diaminodecane, N, N'-di-t-butoxycarbonyl-1,12-diaminododecane, N, N'-di-t Nt such as butoxycarbonyl-4,4′-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, Nt-butoxycarbonyl-2-phenylbenzimidazole, etc. -In addition to butoxycarbonyl group-containing amino compounds,

  Formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone, N-acetyl-1-adamantylamine, isocyanuric An acid tris (2-hydroxyethyl) etc. can be mentioned.

  Examples of urea compounds include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tri-n-butylthiourea. Etc.

  Examples of the nitrogen-containing heterocyclic compound include imidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2- Imidazoles such as methyl-1H-imidazole; pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4-phenylpyridine , Nicotine, nicotinic acid, nicotinamide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine, pyridines such as 2,2 ′: 6 ′, 2 ″ -terpyridine; piperazine, 1- (2-hydroxyethyl ) In addition to piperazines such as piperazine, Gin, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, piperidine ethanol, 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1- (4-morpholinyl) ethanol, 4-acetylmorpholine, 3 Preferred examples include-(N-morpholino) -1,2-propanediol, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane, and the like.

  The photosensitive basic compound is a photosensitive component that efficiently decomposes into neutral fragments in the exposed area and remains as it is without being decomposed in the unexposed area. Since such a photosensitive basic compound can effectively use an acid generated in an exposed portion (that is, an exposed region) as compared with a non-photosensitive basic compound, the sensitivity can be further improved. .

  Although it will not restrict | limit especially as long as it has the said property as a photosensitive basic compound, For example, the compound etc. which are represented by the following general formula (10-1), (10-2) can be mentioned.

In the general formula (10-1), R ^{28 to} R ³⁰ are each independently a hydrogen atom, a halogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, or an optionally substituted group. an alicyclic hydrocarbon ^{group, a} - ^{is, OH -, R 31-, R} 31 COO - is ^{(wherein, R 31} is a monovalent organic group). In the general formula (10-2), R ³² and R ³³ are each independently a hydrogen atom, a halogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, or a substituted atom. a ^{and, a} also alicyclic hydrocarbon groups - ^{is, OH -, R 34 O -} , R 34 COO - is ^{(wherein, R 34} is a monovalent organic group).

Examples of the optionally substituted alkyl group of R ^{28 to} R ³⁰ , R ³² and R ³³ include a methyl group, an ethyl group, an n-butyl group, a tert-butyl group, and trifluoromethyl. Group, fluorine atom, methoxy group, t-butoxy group, t-butoxycarbonylmethyloxy group and the like. Among these, a hydrogen atom and a tert-butyl group are preferable.

Examples of the alicyclic hydrocarbon group which may be substituted for R ^{28 to} R ³⁰ , R ³² and R ³³ include a cyclohexyl group and a cyclopentyl group.

The monovalent organic group for R ³¹ and R ^34, for example, an alkyl group which may be substituted, and the like aryl group which may be substituted.

The A ^{- _{The, OH -, CH 3 COO -}} , a compound represented by the following formula (11-1) to (11-5) are preferable.

Specifically, the photosensitive basic compound is a triphenylsulfonium compound (a compound represented by the above general formula (10-1)), and an anion portion (A ⁻ ) thereof is OH ⁻ , CH ₃ COO. ^-, the compound represented by formula (11-2), the compound represented by formula (11-3), the compound represented by formula (11-4) is preferable.

  In addition, the said acid diffusion control agent (D) can be used individually by 1 type or in combination of 2 or more types.

  The compounding amount of the acid diffusion controller (D) is preferably 15 parts by mass or less, more preferably 0.001 to 10 parts by mass with respect to 100 parts by mass of the resin (A), and 0.005. It is especially preferable that it is -5 mass parts. When the amount is more than 15 parts by mass, the sensitivity of the formed resist film and the developability of the exposed part may be deteriorated. If the amount is less than 0.001 part by mass, the pattern shape and dimensional fidelity of the formed resist film may be lowered depending on the process conditions.

[1-5] Other components:
In addition to the resin (A), acid generator (B), acid proliferation agent (C) and acid diffusion controller (D) described above, the radiation sensitive resin composition of the present invention includes a solvent and various components as other components. The additive may be further blended, and examples of the additive include surfactants, sensitizers, aliphatic additives, dyes, pigments, adhesion aids, alkali-soluble polymers, and acid-dissociable protection. Examples thereof include a low molecular weight alkali solubility control agent having a group, an antihalation agent, a storage stabilizer, and an antifoaming agent.

  Examples of the solvent include linear or branched ketones, cyclic ketones, propylene glycol monoalkyl ether acetates, alkyl 2-hydroxypropionate, alkyl 3-alkoxypropionate, and γ-butyrolactone. At least one selected from the group is preferred.

  The blending amount of the solvent is preferably such that the total solid content concentration of the radiation-sensitive resin composition is 1 to 70% by mass, more preferably 1 to 15% by mass. It is particularly preferable that the amount be 10% by mass. When the blending amount is less than 1% by mass, the viscosity is too high, so that coating may be difficult. On the other hand, if it exceeds 70% by mass, it may be difficult to form a resist film having a sufficient thickness.

  A surfactant is a component that exhibits an effect of improving coating properties, striation, developability, and the like. Examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, and polyethylene glycol dilaurate. In addition to nonionic surfactants such as polyethylene glycol distearate, KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (manufactured by Kyoeisha Chemical Co., Ltd.), F-top EF301, EF303, EF352 (manufactured by Tochem Products), MegaFuck F171, F173 (manufactured by Dainippon Ink and Chemicals), Florard FC430, FC431 (Sumitomo 3M) Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (made by Asahi Glass Co., Ltd.), etc. Can do. These surfactants may be used individually by 1 type, and may be used in combination of 2 or more type.

  It is preferable that the compounding quantity of surfactant is 0.001-2 mass parts with respect to 100 mass parts of resin (A).

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

  Examples of such sensitizers include carbazoles, acetophenones, benzophenones, naphthalenes, phenols, biacetyl, eosin, rose bengal, pyrenes, anthracenes, phenothiazines, and the like. In addition, these sensitizers may be used individually by 1 type, and may be used in combination of 2 or more type.

  It is preferable that the compounding quantity of a sensitizer is 0.1-10 mass parts with respect to 100 mass parts of resin (A).

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

  Examples of such alicyclic additives 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 dicarboxylic acid di-t-butyl, 1-adamantane acetate t-butyl, 1-adamantane acetate t-butoxycarbonylmethyl, 1,3-adamantane diacetate di-t-butyl, 2, Adamantane derivatives such as 5-dimethyl-2,5-di (adamantylcarbonyloxy) hexane;

Deoxycholate t-butyl, deoxycholate t-butoxycarbonylmethyl, deoxycholate 2-ethoxyethyl, deoxycholate 2-cyclohexyloxyethyl, deoxycholate 3-oxocyclohexyl, deoxycholate tetrahydropyranyl, deoxychol Deoxycholic acid esters such as acid mevalonolactone ester; t-butyl lithocholic acid, t-butoxycarbonylmethyl lithocholic acid, 2-ethoxyethyl lithocholic acid, 2-cyclohexyloxyethyl lithocholic acid, 3-oxocyclohexyl lithocholic acid, lithol Lithocholic acid esters such as tetrahydropyranyl acid, lithocholic acid mevalonolactone ester; dimethyl adipate, diethyl adipate, dipropyl adipate, di-n-adipate Chill, alkyl carboxylic acid esters such as adipate t- butyl or 3- [2-hydroxy-2,2-bis (trifluoromethyl) ethyl] tetracyclo [4.4.0.1 ^{2, 5.} 1 ^7,10 ] dodecane and the like.

  In addition, these alicyclic additives may be used individually by 1 type, and may be used in combination of 2 or more type.

  It is preferable that the compounding quantity of an alicyclic additive is 0.5-20 mass parts with respect to 100 mass parts of resin (A). There exists a possibility that the heat resistance of the formed resist film may fall that the said compounding quantity is more than 20 mass parts.

  The dyes and pigments can visualize the latent image of the exposed area and reduce the influence of halation during exposure. Further, the adhesion assistant is for improving the adhesion between the resist film and the substrate.

  The radiation-sensitive resin composition of the present invention includes, for example, the above-described resin (A), acid generator (B), acid proliferation agent (C), acid diffusion controller (D), and other components (solvents). And the like can be mixed with a solvent and uniformly dissolved in the solvent. At this time, it is preferable to adjust so that the total solid content concentration falls within the above range. And after preparing in this way, it is preferable to filter with a filter with a pore diameter of about 0.2 μm, for example.

[2] Method of using radiation-sensitive resin composition:
The radiation sensitive resin composition of the present invention is useful as a material capable of forming a chemically amplified positive resist film. The chemically amplified positive resist film can form a pattern having a desired shape (positive resist pattern). Specifically, when the chemically amplified positive resist film is exposed, an acid is generated from the contained acid generator (B), and the acid dissociation in the resin (A) is caused by the action of the generated acid. Since the group is eliminated, the resin (A) becomes alkali-soluble. Therefore, an alkali-soluble part is generated in the resist film, and a resist film in which a resist pattern having a desired shape is formed by dissolving and removing the alkali-soluble part with an alkali developer. More specific description will be given below.

  In order to form a resist pattern using the radiation sensitive resin composition of the present invention, first, a resist film is formed by applying the radiation sensitive resin composition of the present invention on a substrate. As the radiation-sensitive resin composition, for example, as described above, after adjusting the total solid content concentration, it can be filtered with a filter having a pore diameter of about 0.2 μm. 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.

  Thereafter, in some cases, heat treatment (hereinafter referred to as “PB”) may be performed at a temperature of about 70 to 160 ° C.

  Next, this resist film is exposed so that a predetermined resist pattern is formed. 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 include X-rays such as tron radiation, and charged particle beams such as electron beams. 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. This exposure can also be immersion exposure.

  Note that heat treatment (hereinafter referred to as “PEB”) is preferably performed after the exposure. By this PEB, it is possible to further smoothly proceed with elimination of the acid dissociable group in the resin (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.

  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 can 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.

  Next, the exposed resist film is developed. By developing in this way, a predetermined resist pattern can be 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- [4.3.0] An alkaline aqueous solution in which at least one of alkaline compounds such as 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 individually by 1 type, and may be used in combination of 2 or more type.

  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 undeveloped residue in the exposed part increases. An appropriate amount of a surfactant or the like can be added to the developer.

  In addition, after developing with the developing solution which consists of alkaline aqueous solution, it can also wash with water and can be dried.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example and a comparative example, this invention is not limited to these Examples and a comparative example. In the description of Examples, “parts” and “%” are based on mass unless otherwise specified.

[Measurement of Mw, Mn and degree of dispersion (Mw / Mn)]:
Mw and Mn were measured using “GPC columns (2 G2000HXL, 1 G3000HXL, 1 G4000HXL)” manufactured by Tosoh Corporation, a flow rate of 1.0 ml / min, tetrahydrofuran as an eluting solvent, and a column temperature of 40 ° C. And measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard. Further, the dispersity (Mw / Mn) was calculated from the above measurement results.

[ ¹³ C-NMR analysis]:
^{For the 13} C-NMR analysis, a model “JNM-EX270” manufactured by JEOL Ltd. was used.

[Sensitivity (L / S)]:
While changing the exposure amount, a resist pattern (so-called line and space pattern (1L1S)) composed of a space portion (that is, a groove portion) formed by a line portion adjacent to the line portion was formed. At this time, an exposure amount that makes the line width between the line portion and the space portion one to one (specifically, a line portion with a line width of 150 nm and a space portion with a line width of 150 nm) is an optimum exposure amount, and this optimum exposure is performed. Quantity was evaluated as a measure of sensitivity.

  FIG. 1 is a schematic plan view when a line and space pattern is viewed from above. FIG. 2 is a cross-sectional view schematically showing the A-A ′ cross section shown in FIG. 1. However, the unevenness shown in FIGS. 1 and 2 is drawn exaggerated from the actual.

[Nano edge roughness]:
A line and space pattern (1L1S) having a design line width of 150 nm is formed, and then the line portion of the line and space pattern is scanned with a scanning electron microscope for semiconductors (high resolution FEB measuring device, trade name “S-9220”). , Manufactured by Hitachi, Ltd.), and the height of the most protruding convex portion of the lateral side surface of the line portion was measured. Specifically, as shown in FIGS. 1 and 2, the line width (“X” in FIG. 1) at the most prominent convex portion formed on the lateral surface 2a of the line portion 2 of the resist film formed on the silicon wafer 1 is obtained. And a design line width of 150 nm (“ΔCD” shown in FIGS. 1 and 2) were measured by CD-SEM (manufactured by Hitachi High-Technologies Corporation, “S-9220”). This measured value was used as an evaluation value of nano edge roughness.

[Resolution (L / S)]:
Of the line widths of the line portions of the line-and-space pattern formed in the evaluation of [sensitivity (L / S)], the minimum line width (nm) was used as the evaluation value of resolution.

(Synthesis Example 1) Synthesis of Resin (A-1):
56 g of p-acetoxystyrene, 44 g of a compound (monomer) represented by the following formula (M-1), 4 g of azobisisobutyronitrile (hereinafter referred to as “AIBN”), and 1 g of t-dodecyl mercaptan are mixed with propylene. After dissolving in 100 g of glycol monomethyl ether, the polymerization was carried out for 16 hours while maintaining the reaction temperature at 70 ° C. in a nitrogen atmosphere. After the polymerization, the reaction solution was dropped into 1000 g of n-hexane to coagulate and purify the resulting copolymer. Next, 150 g of propylene glycol monomethyl ether was added to the copolymer, and then 150 g of methanol, 35 g of triethylamine and 7 g of water were further added, and a hydrolysis reaction was performed for 8 hours while refluxing at the boiling point. After the reaction, the solvent and triethylamine were distilled off under reduced pressure, and the obtained copolymer was dissolved in 150 g of acetone, then dropped into 2000 g of water to solidify, and the resulting white powder was filtered and filtered at 50 ° C. under reduced pressure. Dried overnight.

As for the obtained copolymer, Mw is 11000, Mw / Mn is 2.0, and as a result of ¹³ C-NMR analysis, the content ratio (mol) of each repeating unit derived from p-hydroxystyrene and the compound (M-1). The ratio) was a 65:35 copolymer. Hereinafter, this copolymer is referred to as “resin (A-1)”.

(Synthesis Example 2) Synthesis of Resin (A-2):
After dissolving 55 g of p-acetoxystyrene, 45 g of a compound (monomer) represented by the following formula (M-2), 4 g of AIBN, and 1 g of t-dodecyl mercaptan in 100 g of propylene glycol monomethyl ether, the reaction temperature in a nitrogen atmosphere Was kept at 70 ° C. and polymerized for 16 hours. After the polymerization, the reaction solution was dropped into 1000 g of n-hexane to coagulate and purify the resulting copolymer. Next, 150 g of propylene glycol monomethyl ether was added to the copolymer again, and then 150 g of methanol, 34 g of triethylamine and 6 g of water were further added, and a hydrolysis reaction was performed for 8 hours while refluxing at the boiling point. After the reaction, the solvent and triethylamine were distilled off under reduced pressure, and the obtained copolymer was dissolved in 150 g of acetone, then dropped into 2000 g of water to solidify, and the resulting white powder was filtered and filtered at 50 ° C. under reduced pressure. Dried overnight.

As for the obtained copolymer, Mw is 10,000, Mw / Mn is 2.1, and as a result of ¹³ C-NMR analysis, the content ratio (moles) of each repeating unit derived from p-hydroxystyrene and the compound (M-2) The ratio) was a 65:35 copolymer. Hereinafter, this copolymer is referred to as “resin (A-2)”.

  In addition, the detail of each component (The acid generator (B), the acid proliferation agent (C), the acid diffusion control agent (D), and the solvent (E)) used for the Example and the comparative example is shown below.

  As the acid generator (B), compounds represented by the following formulas (B-1) to (B-5) were used.

  As the acid proliferating agent (C), compounds represented by the following formulas (C-1) to (C-5) were used.

  As the acid diffusion controller (D), tri-n-octylamine (shown as “D-1” in Table 1) was used.

  As the solvent (E), ethyl lactate (shown as “E-1” in Table 1) and propylene glycol monomethyl ether acetate (shown as “E-2” in Table 1) were used.

Example 1
100 parts of the resin (A-1) obtained in Synthesis Example 1 as the resin (A), 15 parts of the compound represented by the above formula (B-1) as the acid generator (B), and as the acid proliferating agent (C) 15 parts of the compound represented by (C-1), 2 parts of tri-n-octylamine as the acid diffusion controller (D), 1100 parts of ethyl lactate and 2500 parts of propylene glycol monomethyl ether acetate as the solvent (E) Thus, a mixed solution was obtained, and the obtained mixed solution was filtered through a membrane filter having a pore size of 200 nm to prepare a composition solution (radiation sensitive resin composition).

The prepared composition solution was spin-coated on a silicon wafer in “Clean Track ACT-8” manufactured by Tokyo Electron, Ltd., and then subjected to PB (heat treatment) at 110 ° C. for 60 seconds (conditions shown in Table 2). A resist (radiation sensitive resin composition) film having a thickness of 50 nm was formed. Thereafter, the resist film was irradiated with an electron beam using a simple electron beam drawing apparatus (manufactured by Hitachi, Ltd., model “HL800D”, output: 50 KeV, current density: 5.0 amperes / cm ² ). After the electron beam irradiation, PEB was performed at 110 ° C. for 60 seconds (conditions shown in Table 2). Then, using a 2.38% tetramethylammonium hydroxide aqueous solution, development was performed at 23 ° C. for 1 minute by the paddle method, followed by washing with pure water and drying to obtain a resist on which a predetermined resist pattern was formed. . Each evaluation mentioned above was performed about the resist obtained in this way.

In each evaluation result of this example, the sensitivity was 20 μC / cm ² , the nano edge roughness was 10 nm, and the resolution evaluation was 80 nm.

(Examples 2-9, Comparative Examples 1-4)
Except having used the compound shown in Table 1, and having set it as the compounding quantity shown in Table 1, it carried out similarly to Example 1, and the composition solution (radiation sensitive resin composition) of Examples 2-9 and Comparative Examples 1-4. ) Was prepared. Using the prepared composition solutions, a resist having a predetermined resist pattern formed was obtained in the same manner as in Example 1. Each evaluation mentioned above was performed about the obtained resist. The evaluation results are shown in Table 2.

  As is clear from Table 2, the radiation-sensitive resin compositions of Examples 1 to 9 are excellent in resolution in addition to having good sensitivity as compared with the radiation-sensitive resin compositions of Comparative Examples 1 to 4. It was confirmed that a resist film excellent in nano edge roughness can be formed.

  Specifically, the radiation sensitive resin compositions of Examples 1 to 9 containing the acid proliferating agent (C) ((C-1) to (C-5)) do not contain the acid proliferating agent (C). Compared to the radiation-sensitive resin composition of Comparative Example 3, it is more sensitive to electron beams or extreme ultraviolet rays, has low roughness, is excellent in sensitivity, and has a fine pattern with high accuracy and stability. It was confirmed that a chemically amplified positive resist film that can be formed can be formed.

  Moreover, although the radiation sensitive resin composition of Examples 1-9 and Comparative Examples 1 and 2 contains an acid multiplication agent (C) ((C-1)-(C-5)), it was carried out. Since the radiation sensitive resin compositions of Examples 1 to 9 contain acid generators (B-1) to (B-3) as acid generators (B), the radiation sensitive resin compositions of Comparative Examples 1 and 2 were used. Compared to other products, it has low roughness and excellent sensitivity, and it was confirmed that a chemically amplified positive resist film capable of forming fine patterns with high accuracy and stability can be formed. .

  The radiation-sensitive resin composition of the present invention is suitable as a material for resist coatings used for fine processing in lithography processes using EB, EUV and X-rays, particularly for manufacturing semiconductor devices and the like. It is extremely useful as a material capable of forming a chemically amplified resist for manufacturing semiconductor devices.

Claims (5)

(A) a resin containing a repeating unit having an acid dissociable group;
(B) a radiation sensitive acid generator represented by the following general formula (b1);
(C) The radiation sensitive resin composition containing the compound represented by the following general formula (c1).
M ⁺ Z ⁻ (b1)
(In the general formula (b1), M ⁺ is a monovalent onium cation, and Z ⁻ is a monovalent anion represented by the following general formula (1-1) or (1-2).)

(In the general formula (1-1), R ¹ and R ² are each independently an alkyl group having 1 to 20 carbon atoms substituted with at least one fluorine atom, or R ¹ and R 2. ² are bonded to each other to form a cyclic structure having 1 to 20 carbon atoms that is substituted with at least one fluorine atom, wherein R ³ , R ⁴ , and R ^{5 in the} general formula (1-2). Are each independently an alkyl group having 1 to 20 carbon atoms substituted with at least one fluorine atom, or any two of R ³ , R ⁴ and R ⁵ are bonded to each other, A cyclic structure having 1 to 20 carbon atoms substituted with at least one fluorine atom is formed, and the remaining one is an alkyl group having 1 to 20 carbon atoms substituted with at least one fluorine atom.)

In (Formula (c1), A is a single bond, the following formulas (2-1), a is .R ⁶ is a group represented by the following formula (2-2), or the following formula (2-3) , A hydrogen atom, a hydrocarbon group having 1 to 25 carbon atoms, and R ⁷ is a hydrocarbon group having 1 to 25 carbon atoms which may be substituted with a fluorine atom.)

The radiation sensitive resin composition according to claim 1, wherein the compound represented by the general formula (c1) is a compound represented by the following general formula (c1-1).

(In said general formula (c1-1), R < ⁷ > is a C1-C25 hydrocarbon group which may be substituted by the fluorine atom.) The radiation sensitive resin composition according to claim 1 or 2, wherein M ⁺ in the general formula (b1) is a sulfonium cation or an iodonium cation. The repeating unit having the acid dissociable group contained in the (A) resin is a repeating unit represented by the following general formula (a-1) and a repeating unit represented by the following general formula (a-2) The radiation-sensitive resin composition according to any one of claims 1 to 3, which is at least one of the units.

(In said general formula (a-1), R < ⁸ > is a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group. Each R < ⁹ > is C1-C20 1 independently of each other. whether the valence of the alicyclic hydrocarbon group or a derivative thereof or a linear or branched alkyl group having 1 to 4 carbon atoms, or any two of R ⁹ are bonded to each other, each bond A divalent alicyclic hydrocarbon group or a derivative thereof together with the carbon atom in which the carbon atom is bonded, and the remaining one is a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or carbon (It is a linear or branched alkyl group of formulas 1 to 4.)

(In said general formula (a-2), R < ¹⁰ > is a hydrogen atom, a methyl group, a trifluoromethyl group, or a hydroxymethyl group. Each R < ¹¹ > is C1-C20 1 independently of each other. Is a valent alicyclic hydrocarbon group or a derivative thereof, or a linear or branched alkyl group having 1 to 4 carbon atoms, or any two R ¹¹ are bonded to each other, and each is bonded A divalent alicyclic hydrocarbon group or a derivative thereof together with the carbon atom in which the carbon atom is bonded, and the remaining one is a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or carbon (It is a linear or branched alkyl group of formulas 1 to 4.) The resin (A) is at least one selected from the group consisting of the following general formula (a-3), the following general formula (a-4), and the repeating unit represented by the following general formula (a-5). The radiation sensitive resin composition of Claim 4 which further contains a seed | species.

(In the general formula (a-3), R ¹² is a hydrogen atom or a methyl group, and R ¹³ is a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, or a carbon number. 1 to 12 linear or branched alkoxyl groups, k is an integer of 0 to 3, and l is an integer of 0 to 3.)

(In the general formula (a-4), R ¹⁴ is a hydrogen atom or a methyl group, and R ¹⁵ is a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, or a carbon number. A linear or branched alkoxyl group of 1 to 12. n is an integer of 1 to 3, and m is an integer of 0 to 3.)

(In the general formula (a-5), R ¹⁶ is a hydrogen atom or a methyl group, and R ¹⁷ is a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, or a carbon number. 1 to 12 linear or branched alkoxyl groups, p is an integer of 1 to 3, and q is an integer of 0 to 3)

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