JP2012234062A - Positive resist composition, method for producing relief pattern, and electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positive resist composition, from which a pattern having superior pattern strength, hardly causing pattern collapse and having high resolution and low line edge roughness can be formed, and to provide a method for producing a relief pattern and electronic components using the positive resist composition.SOLUTION: The positive resist composition includes: a phenol derivative mixture (A) having an average one or more phenolic hydroxyl groups in one molecule and an average one or more groups expressed by chemical formula (I) in one molecule, and having an average molecular weight of 400 to 2500; and an acid generator (B) that directly or indirectly generates an acid by irradiation with active energy rays at a wavelength of 248 nm or shorter. In the chemical formula (I), symbols conform to the description in the specification.

Description

  The present invention relates to a positive resist composition for forming a chemically amplified resist useful for microfabrication, a relief pattern manufacturing method using the resist composition, and an electronic component.

In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization has rapidly progressed due to advances in lithography technology. For example, high resolution with a dimension width of 50 nm or less is required.
As a technique for miniaturization, the wavelength of an exposure light source is generally shortened, and in addition to the currently used KrF excimer laser light, ArF, F ₂ , EUV, X-rays, electron beams, and other charged particles Lithography using lines as exposure light has been proposed.

In particular, pattern formation by electron beam and EUV exposure is positioned as next-generation or next-generation lithography technology, and has high sensitivity, high resolution, and low line edge for processing mask patterns formed on semiconductor integrated circuits and glass substrates. Development of a positive resist that satisfies all the requirements of roughness (LINE Edge Roughness, LER) is desired.
As a resist material for these, a chemically amplified photosensitive composition using an acid catalytic reaction is used for the purpose of improving sensitivity. For example, a positive chemically amplified photosensitive composition usually contains a resist substrate in which an acid-decomposable protective group is introduced in advance into the hydrophilic group of an alkali-soluble resin to render the acid insoluble by exposure to light. It contains a generated acid generator component, a basic compound, and the like. Such a photosensitive composition decomposes or dissociates (deprotects) the protecting group by the action of an acid generated from the acid generator component by exposure, and changes from alkali-insoluble to alkali-soluble. In addition, since the generated acid repeats the reaction catalytically, pattern exposure with a smaller exposure amount becomes possible.

As a technique for miniaturization, the wavelength of an exposure light source is generally shortened, and in addition to the currently used KrF excimer laser light, ArF, F ₂ , EUV, X-rays, electron beams, and other charged particles Lithography using lines as exposure light has been proposed. In lithography using each of these exposure lights, a chemical amplification type photosensitive composition with higher sensitivity has come to be used.

  Along with the processing dimensions, the processing accuracy is important. For example, it has been pointed out that a large variation in pattern dimensions given by a line edge roughness (LER) value affects the performance of the semiconductor and becomes a serious problem. In a chemically amplified photosensitive composition, sensitivity, resolving power, and LER are in a reciprocal relationship, and how to make them compatible is a problem.

Conventionally, a resist material based on a polymer compound having a mass average molecular weight of about 10,000 or more has been used for semiconductor lithography.
However, since such a polymer material has a large molecular weight and a wide molecular weight distribution, there is a limit to the processing dimension and processing accuracy in microfabrication.

  Therefore, a low molecular weight material having a low molecular weight and a small molecular size has been developed, and the low molecular weight material is expected to be superior in resolving power as compared with a high molecular weight material and further contribute less to LER. The Examples of such low molecular weight materials include calix resorcinarene derivatives and dendrimer type compounds. Positive resist compositions using the calix resorcinarene derivatives and positive resist compositions using the dendrimer type compounds include: (See Patent Documents 1 to 3).

However, the low molecular weight material as described above has very little molecular chain entanglement like the high molecular weight material, and is an aggregate of relatively weak bonds such as intermolecular force and hydrogen bond. Therefore, there is a problem that a pattern formed using a low molecular material is fragile and easily broken (pattern strength is low) compared to a pattern formed using a high molecular material.
Also, in the aspect ratio indicating the ratio of the width and height of the formed pattern, since the pattern strength is low in the low molecular material, the aspect ratio is smaller than that in the polymer material even with the same pattern width as the polymer material ( There is a problem that the height of the pattern becomes low.

  As a technique for solving these problems, in Patent Document 4, a polyphenol compound having a molecular weight of 300 to 4000 having two or more phenolic hydroxyl groups in one molecule and a crosslinkable compound that reacts with the phenolic hydroxyl group and can be decomposed by the action of an acid. A positive resist composition containing a specific compound having two or more reactive functional groups capable of forming a bond in one molecule and a specific acid generator is disclosed. According to the positive resist composition of Patent Document 4, it is possible to form a pattern having excellent pattern strength and aspect ratio while having high resolution, which is an advantage of a low molecular material. However, in the method of Patent Document 4, the line edge roughness is insufficient as in a comparative example described later.

JP-A-11-322656 JP 2003-321423 A JP 2007-293250 A JP 2009-244724 A

  As a result of intensive studies, the inventors of the present invention have used the resist composition described in Patent Document 4 by mixing a crosslinkable compound in addition to the polyphenol compound that is a resist base material. As a result, phase separation occurred and line edge roughness was insufficient. Therefore, the present inventors considered that it is important to form a more uniform resist film in order to obtain a pattern with high resolution and low line edge roughness.

  The present invention has been made under such circumstances, positive resist composition excellent in pattern strength, resisting pattern collapse, and capable of obtaining a high resolution, low line edge roughness pattern, It is an object of the present invention to provide a relief pattern manufacturing method and an electronic component using a positive resist composition.

  As a result of intensive studies to achieve the above object, the present inventors can reduce the number of components in the composition if designed to have a plurality of functions in one molecule. It was considered that a more uniform resist film can be formed which can improve the non-uniformity of the resist film due to phase separation of components. Under such an idea, the present inventors introduced a specific crosslinkable group into a specific phenolic compound serving as a resist substrate, and used a resist substrate having crosslinkability and alkali developability to thereby obtain a phenolic compound. The inventors have found that a pattern of low line edge roughness can be obtained with high resolving power as compared with the case where two components of a compound and a crosslinking agent are mixed and used, and the present invention has been completed.

  The positive resist composition according to the present invention has an average molecular weight of 400 having an average of one or more phenolic hydroxyl groups in one molecule and an average of one or more groups represented by the following chemical formula (I) in one molecule. It contains ˜2500 phenol derivative mixture (A) and an acid generator (B) that generates an acid directly or indirectly by irradiation with an active energy ray having a wavelength of 248 nm or less.

（化学式（Ｉ）中、Ｒ^ａ〜Ｒ^ｃは、各々独立に、水素原子、アルキル基、又はシクロアルキル基を表し、Ｒ^ａ〜Ｒ^ｃの２つが結合して３〜８個の炭素原子又はヘテロ原子からなる環構造を形成してもよい。Ｒ^ｄは、直鎖又は分岐の炭素数１〜６のアルキレン基、シクロアルキレン基、及びこれらの組み合わせよりなる群から選ばれる基である。）

(In the chemical formula (I), R ^{a to} R ^c each independently represents a hydrogen atom, an alkyl group, or a cycloalkyl group, and two of R ^{a to} R ^c are bonded to form 3 to 8 carbon atoms or A ring structure composed of heteroatoms may be formed, and R ^d is a group selected from the group consisting of linear or branched alkylene groups having 1 to 6 carbon atoms, cycloalkylene groups, and combinations thereof.

  In the positive resist composition according to the present invention, the phenol derivative mixture (A) has a development rate of 0.5 nm / sec with respect to an aqueous solution of 2.38 wt% tetramethylammonium hydroxide (TMAH) at 23 ° C. The above is preferable from the viewpoint that developability is good and a pattern with high resolution and low line edge roughness can be obtained.

  In the positive resist composition according to the present invention, the phenol derivative mixture (A) has a structure in which the hydrogen of the phenolic hydroxyl group is substituted with the group represented by the above chemical formula (I). It is preferable because it is excellent in resistance to pattern collapse, and a pattern with high resolution and low line edge roughness can be obtained.

  In the positive resist composition according to the present invention, it is preferable to further contain an organic basic compound (C) from the viewpoint of improving the resist pattern shape and improving the storage stability over time.

  In the positive resist composition according to the present invention, the phenol derivative mixture (A) is a phenol derivative mixture represented by the following chemical formula (1), which is excellent in pattern strength, hardly causes pattern collapse, and This is preferable because a pattern with high resolution and low line edge roughness can be obtained.

［化学式（１）中、Ｒ^１は、各々独立に、水素原子、アルキル基、シクロアルキル基、アリール基、及び下記化学式（２）に示す基からなる群より選ばれる基であり、Ｒ^１に含まれるアリール基は、水酸基及び／又は下記化学式（Ｉ）で表される基を有しても良い。

[In the chemical formula (1), R ¹ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, and a group selected from the group consisting of groups represented by the following chemical formula (2), the R ¹ The aryl group contained may have a hydroxyl group and / or a group represented by the following chemical formula (I).

（化学式（２）中、Ｒ^４及びＲ^５は、各々独立に、水素原子又は炭素数１〜３のアルキル基であり、Ｑは、アリール基又はシクロアルキル基であり、ｍは１又は２を表す。）
Ｒ^２は、各々独立に、水素原子又は１価の有機基であり、複数あるＲ^２のうち、１分子中平均１個以上は水素原子であり、１分子中平均１個以上は下記化学式（Ｉ）で表される基である。Ｒ^３は、ハロゲン原子、アルキル基、シクロアルキル基、アリール基、アルコキシ基、アシル基、シアノ基、ニトロ基、ヒドロキシメチル基、及びアルコキシメチル基よりなる群から選ばれる基である。

(In the chemical formula (2), R ⁴ and R ⁵ are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, Q is an aryl group or a cycloalkyl group, and m is 1 or 2. Represents.)
R ^{2 s} are each independently a hydrogen atom or a monovalent organic group, and among the plurality of R ² , one or more on average in one molecule is a hydrogen atom, and one or more on average in one molecule is represented by the following chemical formula ( It is a group represented by I). R ³ is a group selected from the group consisting of halogen atoms, alkyl groups, cycloalkyl groups, aryl groups, alkoxy groups, acyl groups, cyano groups, nitro groups, hydroxymethyl groups, and alkoxymethyl groups.

（化学式（Ｉ）中、Ｒ^ａ〜Ｒ^ｃは、各々独立に、水素原子、アルキル基、又はシクロアルキル基を表し、Ｒ^ａ〜Ｒ^ｃの２つが結合して３〜８個の炭素原子又はヘテロ原子からなる環構造を形成してもよい。Ｒ^ｄは、直鎖又は分岐の炭素数１〜６のアルキレン基、シクロアルキレン基、及びこれらの組み合わせよりなる群から選ばれる基である。）
ｎ１は１〜３の整数、ｎ２は０〜２の整数を表す。但し、ｎ１＋ｎ２≦４となる組み合わせをｎ１及びｎ２の数値範囲から選択するものとする。ｘ１は３〜１２の整数を表す。
また、化学式（１）に含まれる同一符号で表される基は、互いに同じでも異なっていてもよい。］

(In the chemical formula (I), R ^{a to} R ^c each independently represents a hydrogen atom, an alkyl group, or a cycloalkyl group, and two of R ^{a to} R ^c are bonded to form 3 to 8 carbon atoms or A ring structure composed of heteroatoms may be formed, and R ^d is a group selected from the group consisting of linear or branched alkylene groups having 1 to 6 carbon atoms, cycloalkylene groups, and combinations thereof.
n1 represents an integer of 1 to 3, and n2 represents an integer of 0 to 2. However, a combination satisfying n1 + n2 ≦ 4 is selected from a numerical range of n1 and n2. x1 represents the integer of 3-12.
In addition, the groups represented by the same symbols included in the chemical formula (1) may be the same as or different from each other. ]

  In the positive resist composition according to the present invention, when the glass transition temperature (Tg) of the phenol derivative mixture (A) is 60 ° C. or higher, a pattern with high resolution and low line edge roughness can be obtained. It is preferable from the point.

The method for producing a relief pattern according to the present invention includes:
(I) a step of applying a positive resist composition according to the present invention on a substrate and then heat-treating to form a resist film; and (ii) applying the resist film to an electron beam, ion beam, EUV, or X-ray. And exposing and developing.
According to the present invention, it is possible to form a low line edge roughness pattern with high sensitivity and high resolution.

  The present invention also provides an electronic component that is at least partially formed from the positive resist composition according to the present invention or a cured product thereof.

  According to the present invention, a positive resist composition that is excellent in pattern strength, resists pattern collapse, and can obtain a pattern with high resolution and low line edge roughness, and a relief pattern using the positive resist composition The manufacturing method and electronic component can be provided.

The present invention is described in detail below.
In the present invention, “active energy rays” mean far ultraviolet rays such as KrF excimer laser, ArF excimer laser, and F ₂ excimer laser, electron beams, ion beams, EUV, X-rays, and the like.
Moreover, in the description of the group (atomic group) in this invention, the description which has not described substitution and non-substitution includes what has a substituent with what does not have a substituent. For example, the “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group). The divalent bond of the alkylene group includes a divalent bond from the same carbon atom (for example, —CH ₂ —) as well as a case from a different carbon atom (for example, —CH ₂ CH ₂ —). Moreover, an alkyl group and a cycloalkyl group include unsaturated hydrocarbons having double bonds, triple bonds and the like in addition to saturated hydrocarbons. Cycloalkyl groups include monocyclic as well as polycyclic hydrocarbons such as bicyclic and tricyclic.

I. Positive resist composition The positive resist composition according to the present invention has an average of one or more phenolic hydroxyl groups in one molecule and an average of one or more groups represented by the following chemical formula (I) in one molecule. It has a phenol derivative mixture (A) having an average molecular weight of 400 to 2500 and an acid generator (B) that generates an acid directly or indirectly by irradiation with an active energy ray having a wavelength of 248 nm or less. And

（化学式（Ｉ）中、Ｒ^ａ〜Ｒ^ｃは、各々独立に、水素原子、アルキル基、又はシクロアルキル基を表し、Ｒ^ａ〜Ｒ^ｃの２つが結合して３〜８個の炭素原子又はヘテロ原子からなる環構造を形成してもよい。Ｒ^ｄは、直鎖又は分岐の炭素数１〜６のアルキレン基、シクロアルキレン基、及びこれらの組み合わせよりなる群から選ばれる基である。）

(In the chemical formula (I), R ^{a to} R ^c each independently represents a hydrogen atom, an alkyl group, or a cycloalkyl group, and two of R ^{a to} R ^c are bonded to form 3 to 8 carbon atoms or A ring structure composed of heteroatoms may be formed, and R ^d is a group selected from the group consisting of linear or branched alkylene groups having 1 to 6 carbon atoms, cycloalkylene groups, and combinations thereof.

  According to the positive resist composition of the present invention, it is possible to obtain a pattern having excellent pattern strength, pattern collapse hardly occurring, and high resolution and low line edge roughness.

By using the specific phenol derivative mixture (A) and the specific acid generator (B) in combination, the following effects can be estimated as follows.
Conventionally, a chemically amplified positive resist usually contains an acid generator that generates an acid upon exposure and a compound in which an alkali-soluble group is previously protected by a protecting group. The dissociation reaction proceeds and the alkali solubility in the exposed area is increased, so that pattern formation is possible. However, when a polymer material is used, there is a limit to the processing dimensions and processing accuracy in microfabrication, and furthermore, swelling tends to occur during development, and this swelling causes a decrease in resolution and a deterioration in line edge roughness. On the other hand, in the case of a low molecular weight material, there are problems that the pattern strength is low, the pattern is brittle, and is easily broken.
As a technique for solving this problem, the present inventor has developed a polyphenol compound having a molecular weight of 300 to 4000 having two or more phenolic hydroxyl groups in one molecule, and a crosslinkable bond capable of decomposing by the action of an acid by reacting with the phenolic hydroxyl group. A positive resist composition containing a specific compound having two or more reactive functional groups in one molecule and a specific acid generator has been proposed (Patent Document 4). According to this method, since the polyphenol compound is crosslinked through the specific compound having the reactive functional group by heating at the time of forming the coating film, the unexposed portion is excellent in pattern strength. In addition, since the cross-linking bond is decomposed or dissociated by the generated acid, the exposed portion returns to the low molecular material, and the phenolic hydroxyl group is regenerated and dissolved to form a high resolution pattern. However, since the resist composition of Patent Document 4 is used by mixing the specific compound having the reactive functional group in addition to the polyphenol compound which is a resist substrate, the problem of compatibility of each component occurs, It is estimated that the phases are separated. In such a case, since a uniform resist film cannot be produced, it is estimated that the line edge roughness deteriorates.

  On the other hand, in the present invention, an average molecular weight of 400 to 2500 having an average of one or more phenolic hydroxyl groups in one molecule and an average of one or more groups represented by the above chemical formula (I) in one molecule. Since the phenol derivative mixture (A) is used, the phenolic hydroxyl group of the phenol derivative mixture (A) and the group represented by the above chemical formula (I) can be represented, for example, by the following formula without separately mixing a crosslinkable compound. It is presumed that the phenol derivative mixture (A) can be linked to each other and the phase separation problem does not occur. Thereby, a resist film with higher uniformity and higher pattern strength can be produced. And since the said connection part dissociates by the acid which generate | occur | produced from the acid generator (B) in an exposure part, since it returns to a low molecular component and a phenolic hydroxyl group is reproduced | regenerated and melt | dissolved, a high resolution pattern is obtained. Estimated. Moreover, since the connection state of the phenol derivative mixture (A) with high uniformity is maintained in the unexposed area, it is presumed that a pattern with high pattern strength and low line edge roughness can be obtained.

The positive resist composition according to the present invention comprises a phenol derivative mixture (A) and an acid generator (B) as essential components, and may contain other components as necessary.
Hereinafter, each component of the positive resist composition will be described in order.

<Phenol derivative mixture (A)>
The phenol derivative mixture (A) used in the present invention has an average of one or more phenolic hydroxyl groups in one molecule and an average of one or more groups represented by the above chemical formula (I) in one molecule. It is a compound having a molecular weight of 400-2500. By setting the average molecular weight of the phenol derivative mixture (A) within the above range, high resolution and low line edge roughness can be achieved.
In the present invention, “phenolic hydroxyl group” means a hydroxyl group directly bonded to an aromatic ring such as benzene.

  The phenol derivative mixture (A) of the present invention has an average of one or more phenolic hydroxyl groups in one molecule and an average of one or more groups represented by the above chemical formula (I) in one molecule. Therefore, the phenol derivative mixture (A) of the present invention has alkali solubility in the state of the composition before coating film formation (before heating), and after coating film formation (after heating) is represented by the above chemical formula (I). Group reacts with a phenolic hydroxyl group to form an acetal structure, so that alkali solubility is lost. After irradiation with light, only the acid generating part, the acetal structure is decomposed by the influence of acid, and returns to a low molecular component. The phenolic hydroxyl group is regenerated and becomes alkali-soluble again.

The phenol derivative mixture (A) used in the present invention may have an average of one or more phenolic hydroxyl groups in one molecule, and the number of phenolic hydroxyl groups in one molecule is not particularly limited. Among them, the phenol derivative mixture (A) has an average of 2 phenolic hydroxyl groups in one molecule because it is excellent in pattern strength, resists pattern collapse, and can obtain a pattern with high resolution and low line edge roughness. It is preferable to have at least one.
In addition, since a phenol derivative mixture (A) should just have an average of 1 or more phenolic hydroxyl groups in 1 molecule, the molecule | numerator which does not have a phenolic hydroxyl group may be contained. However, it is preferable that each molecule has one or more phenolic hydroxyl groups, and more preferably two or more from the viewpoint of excellent pattern strength, resistance to pattern collapse, and excellent alkali developability.

Among them, the phenol derivative mixture (A) used in the present invention is preferably selected as appropriate so that the average number of phenolic hydroxyl groups introduced is alkali-soluble based on the following.
The phenol derivative mixture (A) is preferably selected and used at a development rate of 0.5 nm / sec or more with respect to an aqueous solution of tetramethylammonium hydroxide (TMAH) having a concentration of 2.38% by weight (23 ° C.). Furthermore, it is preferable to select and use one that is 1.0 nm / sec or more. By making the alkali development speed of the alkali-soluble resin within the above range, the pattern shape can be improved.

  For example, the development rate for a 2.38 wt% concentration of tetramethylammonium hydroxide (TMAH) aqueous solution (23 ° C.) is, for example, the above-mentioned phenol derivative mixture (A) alone, for example, a 5 wt% solution, After the coating film is formed on the silicon wafer so that the film thickness after drying becomes 300 nm, it is immersed in a tetramethylammonium hydroxide (TMAH) aqueous solution (23 ° C.) having a concentration of 2.38% by weight. The time until dissolution can be measured and calculated.

  The phenol derivative mixture (A) used in the present invention may have an average of at least one group represented by the following chemical formula (I) and represented by the following chemical formula (I) in one molecule. The number of groups is not particularly limited.

（化学式（Ｉ）中、Ｒ^ａ〜Ｒ^ｃは、各々独立に、水素原子、アルキル基、又はシクロアルキル基を表し、Ｒ^ａ〜Ｒ^ｃの２つが結合して３〜８個の炭素原子又はヘテロ原子からなる環構造を形成してもよい。Ｒ^ｄは、直鎖又は分岐の炭素数１〜６のアルキレン基、シクロアルキレン基、及びこれらの組み合わせよりなる群から選ばれる基である。）

(In the chemical formula (I), R ^{a to} R ^c each independently represents a hydrogen atom, an alkyl group, or a cycloalkyl group, and two of R ^{a to} R ^c are bonded to form 3 to 8 carbon atoms or A ring structure composed of heteroatoms may be formed, and R ^d is a group selected from the group consisting of linear or branched alkylene groups having 1 to 6 carbon atoms, cycloalkylene groups, and combinations thereof.

  The group represented by the chemical formula (I) is a group that reacts with and links with a phenolic hydroxyl group by heating at about 80 to 160 ° C. when forming a coating film. The group represented by the above chemical formula (I) itself is not decomposed by an acid, and generally does not correspond to an acid-decomposable group introduced in a positive photosensitive resin composition.

The alkyl group for R ^{a to} R ^c is not particularly limited. Especially, the alkyl group which may have a C1-C8 substituent is preferable, for example, the methyl group which may have a substituent, an ethyl group, a propyl group, n-butyl group, sec-butyl. Group, hexyl group, 2-ethylhexyl group, octyl group and the like.
The cycloalkyl group in R ^{a to} R ^c is not particularly limited. Among them, a cycloalkyl group which may have a substituent having 3 to 8 carbon atoms is preferable, and examples thereof include a cyclopropyl group, a cyclopentyl group and a cyclohexyl group which may have a substituent.
Further, any two of R ^{a to} R ^c may be bonded to each other to form a ring by combining two arbitrary ring structures composed of 3 to 8 carbon atoms or heteroatoms. Examples of such a ring include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a dihydrofuranyl group, and a dihydropyranyl group, and these rings may further have a substituent. .

Examples of the alkylene group for R ^d include a methylene group, an ethylene group, a propylene group, a butylene group, and an isobutylene group, and may further have a substituent.
The cycloalkylene group in R ^d may be monocyclic or polycyclic, and examples thereof include a cyclopentylene group and a cyclohexylene group, and may further have a substituent.

Examples of the substituent that R ^{a to} R ^d may have include a hydroxyl group, a halogen atom (fluorine, chlorine, bromine, iodine), a nitro group, a cyano group, an amide group, a sulfonamide group, an alkyl group, a methoxy group, C1-C8 alkoxy groups such as ethoxy group, hydroxyethoxy group, propoxy group, hydroxypropoxy group and butoxy group, alkoxycarbonyl groups such as methoxycarbonyl group and ethoxycarbonyl group, acyl groups such as formyl group and acetyl group, Examples include an acyloxy group such as an acetoxy group and a butyryloxy group.

The group represented by the chemical formula (I) is preferably an alkyl vinyl ether group as the group represented by the chemical formula (I) from the viewpoint of high reactivity and easy availability.
Examples of the alkyl vinyl ether group include a methyl vinyl ether group, an ethyl vinyl ether group, an isopropyl vinyl ether group, an n-propyl vinyl ether group, an n-butyl vinyl ether group, an isobutyl vinyl ether group, a 2-ethylhexyl vinyl ether group, and a cyclohexyl vinyl ether group.

The phenol derivative mixture (A) has 1 group represented by the above chemical formula (I) because it is excellent in pattern strength, resists pattern collapse, and can obtain a pattern with high resolution and low line edge roughness. It is preferable to have an average of 1.2 or more, more preferably 1.5 or more, in the molecule.
In addition, since the phenol derivative mixture (A) may have an average of at least one group represented by the chemical formula (I) in one molecule, a molecule not having the group represented by the chemical formula (I) It may be included. However, it is preferable that each molecule has one or more groups represented by the above chemical formula (I) from the viewpoint of excellent pattern strength, resistance to pattern collapse, and excellent alkali developability.

  Moreover, in each molecule | numerator which comprises a phenol derivative mixture (A), it is preferable to have 2 or more in total and phenolic hydroxyl group and group represented by the said Chemical formula (I), and it is more preferable to have 3 or more in total. When the phenolic hydroxyl group and the group represented by the above chemical formula (I) have a total of three or more, the phenol derivative mixture (A) is three-dimensionally cross-linked, so that the pattern strength is excellent and the pattern collapse hardly occurs. .

  The ratio of the average number of phenolic hydroxyl groups in the whole phenol derivative mixture (A) and the average number of groups represented by the above chemical formula (I) is not particularly limited. From the viewpoints of reactivity and alkali developability, the average number of phenolic hydroxyl groups is preferably the same or larger than the average number of groups represented by the above chemical formula (I). The ratio of the average number of phenolic hydroxyl groups to the average number of groups represented by the chemical formula (I) is preferably 50:50 to 90:10. Within this range, the linking reaction of the phenolic hydroxyl group and the group represented by the above chemical formula (I) proceeds efficiently and unreacted phenolic hydroxyl group remains, so that the alkali developability is excellent.

  In the phenol derivative mixture (A), the group represented by the chemical formula (I) may be contained in any manner. Among these, from the viewpoint of easy synthesis, the phenol derivative mixture (A) preferably has a structure in which the hydrogen of the phenolic hydroxyl group is substituted with the group represented by the above chemical formula (I). In the case where the hydrogen of the phenolic hydroxyl group has a structure substituted with the group represented by the above chemical formula (I), the movement of the group represented by the chemical formula (I) is improved through the ether group, It can also be expected that the reaction efficiency is improved.

As the phenol derivative mixture (A) used in the present invention, a compound having an average molecular weight of 400 to 2500 is selected and used. If the average molecular weight is less than the lower limit, the ability to form a resist film and the ability to form a pattern are inferior. On the other hand, when the molecular weight exceeds the upper limit value, it becomes difficult to form a fine pattern, and swelling easily occurs during development, which may cause pattern collapse. Here, the molecular weight refers to the sum of the atomic weights of the atoms constituting the molecule, and the average molecular weight is an average value of the molecular weights of the respective molecules constituting the phenol derivative mixture (A). Moreover, when it is an oligomer which has molecular weight distribution, let the weight average molecular weight using GPC (polystyrene conversion) be an average molecular weight of a phenol derivative mixture (A).
In particular, the average molecular weight of the phenol derivative mixture (A) used in the present invention is preferably 500 to 2500, and more preferably 600 to 2000 from the viewpoint of film formability and resolution.

The phenol derivative mixture (A) used in the present invention preferably has a glass transition temperature (Tg) of 60 ° C. or higher, more preferably 90 ° C. or higher. When the glass transition temperature is 60 ° C. or higher, a dewetting phenomenon hardly occurs when forming a coating film, and a uniform film is easily obtained. The dewetting phenomenon is a phenomenon in which a spread coating film is dissolved during pre-baking to cause repelling and a film is not formed uniformly.
Usually, as a solvent for a resist composition, when a low boiling point solvent is used, the resist film is dried rapidly and a uniform film cannot be obtained. In order to obtain, a solvent having a boiling point of 90 to 180 ° C. is used. Since the resist film formed by spin coating contains a large amount of residual solvent, the resist substrate is heated at a temperature of 90 ° C. or higher with a hot plate in order to form a stable resist film excluding this solvent (pre-baking). . However, when a phenol derivative mixture (A) having a glass transition temperature of less than 60 ° C. is used, a dewetting phenomenon of the resist film occurs in the pre-bake process, and a uniform film may not be obtained.
In contrast, when a phenol derivative mixture having a glass transition temperature of 60 ° C. or higher is used, pre-baking at a high temperature is possible, a uniform film is obtained, and a resist film excellent in environmental resistance (post coating delay: PCD). Is obtained. Furthermore, it is possible to suppress the dependence of the pattern density on the pattern formation by the electron beam. Further, in the dry etching process after the resist pattern is formed, a pattern having excellent etching resistance (can prevent melting of the pattern due to high temperature during etching) can be obtained.
The glass transition temperature here is measured by a differential scanning calorimeter (DSC).

  Moreover, it is preferable that the phenol derivative mixture (A) used in the present invention has a solubility of 5% by weight or more at 23 ° C. in an organic solvent having a boiling point of 80 to 180 ° C. In such a case, it is possible to prevent the resist film from being rapidly dried during spin coating, and there is an advantage that a uniform resist film can be obtained. Typical examples of organic solvents having a boiling point of 80 to 180 ° C. include cyclopentanone, propylene glycol monomethyl ether, cyclohexanone, propylene glycol monomethyl ether acetate, ethyl lactate, 2-heptanone, diethylene glycol dimethyl ether, 1-ethoxy-2-propanol, and the like. Is mentioned.

  It does not specifically limit as said phenol derivative mixture (A), It can select suitably and can be used. Examples thereof include compounds represented by the following chemical formula (1) and chemical formula (3).

［化学式（１）中、Ｒ^１は、各々独立に、水素原子、アルキル基、シクロアルキル基、アリール基、及び下記化学式（２）に示す基からなる群より選ばれる基であり、Ｒ^１に含まれるアリール基は、水酸基及び／又は下記化学式（Ｉ）で表される基を有しても良い。

[In the chemical formula (1), R ¹ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, and a group selected from the group consisting of groups represented by the following chemical formula (2), the R ¹ The aryl group contained may have a hydroxyl group and / or a group represented by the following chemical formula (I).

（化学式（２）中、Ｒ^４及びＲ^５は、各々独立に、水素原子又は炭素数１〜３のアルキル基であり、Ｑは、アリール基又はシクロアルキル基であり、ｍは１又は２を表す。）
Ｒ^２は、各々独立に、水素原子又は１価の有機基であり、複数あるＲ^２のうち、１分子中平均１個以上は水素原子であり、１分子中平均１個以上は下記化学式（Ｉ）で表される基である。Ｒ^３は、ハロゲン原子、アルキル基、シクロアルキル基、アリール基、アルコキシ基、アシル基、シアノ基、ニトロ基、ヒドロキシメチル基、及びアルコキシメチル基よりなる群から選ばれる基である。

(In the chemical formula (2), R ⁴ and R ⁵ are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, Q is an aryl group or a cycloalkyl group, and m is 1 or 2. Represents.)
R ^{2 s} are each independently a hydrogen atom or a monovalent organic group, and among the plurality of R ² , one or more on average in one molecule is a hydrogen atom, and one or more on average in one molecule is represented by the following chemical formula ( It is a group represented by I). R ³ is a group selected from the group consisting of halogen atoms, alkyl groups, cycloalkyl groups, aryl groups, alkoxy groups, acyl groups, cyano groups, nitro groups, hydroxymethyl groups, and alkoxymethyl groups.

（化学式（Ｉ）中、Ｒ^ａ〜Ｒ^ｃは、各々独立に、水素原子、アルキル基、又はシクロアルキル基を表し、Ｒ^ａ〜Ｒ^ｃの２つが結合して３〜８個の炭素原子又はヘテロ原子からなる環構造を形成してもよい。Ｒ^ｄは、直鎖又は分岐の炭素数１〜６のアルキレン基、シクロアルキレン基、及びこれらの組み合わせよりなる群から選ばれる基である。）
ｎ１は１〜３の整数、ｎ２は０〜２の整数を表す。但し、ｎ１＋ｎ２≦４となる組み合わせをｎ１及びｎ２の数値範囲から選択するものとする。ｘ１は３〜１２の整数を表す。
また、化学式（１）に含まれる同一符号で表される基は、互いに同じでも異なっていてもよい。］

(In the chemical formula (I), R ^{a to} R ^c each independently represents a hydrogen atom, an alkyl group, or a cycloalkyl group, and two of R ^{a to} R ^c are bonded to form 3 to 8 carbon atoms or A ring structure composed of heteroatoms may be formed, and R ^d is a group selected from the group consisting of linear or branched alkylene groups having 1 to 6 carbon atoms, cycloalkylene groups, and combinations thereof.
n1 represents an integer of 1 to 3, and n2 represents an integer of 0 to 2. However, a combination satisfying n1 + n2 ≦ 4 is selected from a numerical range of n1 and n2. x1 represents the integer of 3-12.
In addition, the groups represented by the same symbols included in the chemical formula (1) may be the same as or different from each other. ]

（化学式（３）中、
Ｒ^６、Ｒ^７、Ｒ^８及びＲ^９は、各々独立に、水素原子、アルキル基、シクロアルキル基、アリール基、或いは、これらの組み合わせからなる基を表す。Ｒ^６、Ｒ^７、Ｒ^８及びＲ^９に含まれるアリール基は、水酸基及び／又は上記化学式（Ｉ）で表される基を有しても良い。複数のＲ^６が結合して環を形成してもよい。複数のＲ^７が結合して環を形成してもよい。複数のＲ^８が結合して環を形成してもよい。複数のＲ^９が結合して環を形成してもよい。また、複数あるＲ^６、Ｒ^７、Ｒ^８及びＲ^９は互いに同じであっても異なっていても良い。
Ｒ^１０及びＲ^１１は、各々独立に、水素原子又は１価の有機基を表し、複数あるＲ^１０又はＲ^１１のうち、１分子中平均１個以上は水素原子であり、１分子中平均１個以上は上記化学式（Ｉ）で表される基である。
Ｗは単結合、エーテル結合、チオエーテル結合、又は、ヘテロ原子を含んでいてもよい、アルキレン基、シクロアルキレン基、又はアリーレン基、或いは、これらの任意の組み合わせからなる基を表す。複数あるＷは互いに同じであっても異なっていても良い。
ｘ２は正の整数を表す。
ｙ１は０以上の整数を表し、Ｗが単結合の場合、ｙ１は０である。
ｙ２は０以上の整数を表し、ｙ３は正の整数を表す。
ｚは０以上の整数を表す。
ｖは０以上の整数を表す。
ｋ１及びｋ４は正の整数を表す。
ｋ２、ｋ３、及びｋ５は各々独立して０以上の整数を表す。但し、ｋ１＋ｋ２＋ｚ＝５、ｋ３＋ｖ＝３、ｋ４＋ｋ５＝５、ｋ２＋ｋ５≧２を満たす。）

(In the chemical formula (3),
R ⁶ , R ⁷ , R ⁸ and R ⁹ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a group consisting of a combination thereof. The aryl group contained in R ⁶ , R ⁷ , R ⁸ and R ⁹ may have a hydroxyl group and / or a group represented by the above chemical formula (I). A plurality of R ⁶ may combine to form a ring. A plurality of R ⁷ may combine to form a ring. A plurality of R ⁸ may combine to form a ring. A plurality of R ⁹ may combine to form a ring. A plurality of R ⁶ , R ⁷ , R ⁸ and R ⁹ may be the same as or different from each other.
R ¹⁰ and R ¹¹ each independently represent a hydrogen atom or a monovalent organic group, and among a plurality of R ¹⁰ or R ¹¹ , one or more on average per molecule is a hydrogen atom, and an average of 1 per molecule These are groups represented by the above chemical formula (I).
W represents a single bond, an ether bond, a thioether bond, or an alkylene group, a cycloalkylene group, an arylene group, or any combination thereof, which may contain a hetero atom. Plural Ws may be the same or different.
x2 represents a positive integer.
y1 represents an integer of 0 or more. When W is a single bond, y1 is 0.
y2 represents an integer of 0 or more, and y3 represents a positive integer.
z represents an integer of 0 or more.
v represents an integer of 0 or more.
k1 and k4 represent positive integers.
k2, k3, and k5 each independently represents an integer of 0 or more. However, k1 + k2 + z = 5, k3 + v = 3, k4 + k5 = 5, and k2 + k5 ≧ 2 are satisfied. )

In the compound represented by the chemical formula (1), the alkyl group for R ¹ is not particularly limited, but an alkyl group having 1 to 18 carbon atoms is preferable. The alkyl group may be linear or branched. For example, methyl group, ethyl group, n-propyl group, n-butyl group, i-propyl group, i-butyl group, t-butyl group, i-pentyl group, t-pentyl group, hexadecyl group and the like can be mentioned. Moreover, you may have unsaturated bonds, such as a double bond and a triple bond.

  Examples of the substituent that the alkyl group has include a hydroxyl group, an alkoxy group, a halogen atom, and a halogenoalkyl group.

The cycloalkyl group of R ^1, is not particularly limited, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group and the like. Further, it may have an unsaturated bond such as a double bond or a triple bond, and may be monocyclic or polycyclic.
As the cycloalkyl group, a cyclohexyl group is preferable.

  The substituent that the cycloalkyl group has is not particularly limited, and examples thereof include an alkyl group having 1 to 5 carbon atoms, a hydroxyl group, an alkoxy group, an alkoxyalkyl group, a halogen atom, and a halogenoalkyl group.

  The alkyl group having 1 to 5 carbon atoms may be linear or branched. As a linear alkyl group, a methyl group, an ethyl group, n-propyl group, n-butyl group etc. are mentioned, for example. Examples of the branched alkyl group include i-propyl group, i-butyl group, t-butyl group, i-pentyl group, t-pentyl group and the like.

  The alkoxy group is not particularly limited, but is preferably an alkoxy group having 1 to 8 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and a 2-ethylhexyloxy group.

  Although there is no restriction | limiting in particular as an alkoxyalkyl group, A C1-C8 alkoxyalkyl group is preferable, For example, a methoxymethyl group, an ethoxymethyl group, a methoxyethyl group, an ethoxyethyl group, a methoxypropyl group etc. are mentioned.

  Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

  The halogenoalkyl group is not particularly limited, but is preferably a halogenoalkyl group having 1 to 8 carbon atoms. For example, a chloromethyl group, a dichloromethyl group, a trichloromethyl group, a bromomethyl group, a dibromomethyl group, a tribromomethyl group, Fluoromethyl group, difluoromethyl group, trifluoromethyl group, 1-chloroethyl group, 1-bromoethyl group, 1-fluoroethyl group, 1,2-dichloroethyl group, 1,1,2,2-tetrachloroethyl group, etc. Can be mentioned.

The aryl group of R ^1, is not particularly limited, preferably 6 to 14 carbon atoms, more preferably 6 to 10 carbon atoms, for example, a phenyl group, a naphthyl group, an anthryl group and the like.

In addition, examples of the substituent that the aryl group has include a hydroxyl group, a group represented by the above chemical formula (I), a group having a group represented by the above chemical formula (I), a cycloalkyl group, and an alkyl group having 1 to 5 carbon atoms. , Alkoxy groups, alkoxyalkyl groups, halogen atoms, halogenoalkyl groups and the like.
Examples of the cycloalkyl group as a substituent that the aryl group has are the same as those described above. The cycloalkyl group may have a substituent, and examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a halogen atom, a cyano group, a hydroxyl group, and an alkoxy group. Examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, and an i-propyl group. Although there is no restriction | limiting in particular as an alkoxy group, A C1-C8 alkoxy group is preferable, For example, a methoxy group, an ethoxy group, a propoxy group, a butoxy group, 2-ethylhexyloxy group etc. are mentioned.
The alkyl group having 1 to 5 carbon atoms, the alkoxy group, the alkoxyalkyl group, the halogen atom, the halogenoalkyl group, and the alkoxymethyl group as the substituent that the aryl group has are as described above.

In the chemical formula (2), R ⁴ and R ⁵ are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. The alkyl group having 1 to 3 carbon atoms may be either linear or branched, and among them, a methyl group and an ethyl group are preferable from the viewpoint of etching resistance. When m is 2, two R ⁴ and R ⁵ may be the same or different.
In the chemical formula (2), a case where both R ⁴ and R ⁵ are hydrogen atoms is preferably used.

  Examples of the aryl group of Q in the chemical formula (2) include the same aryl groups as those described above. Further, examples of the cycloalkyl group of Q in the chemical formula (2) include the same cycloalkyl groups as those described above. Examples of the substituent that the cycloalkyl group of Q has are the same as the substituents that the cycloalkyl group has.

The monovalent organic group for R ² is not particularly limited as long as one or more of its average in one molecule is a group represented by the above chemical formula (I). Examples of the substituent other than the group represented by the chemical formula (I) include an alkyl group, a cycloalkyl group, and an aryl group.
Examples of the alkyl group for R ² include the same as those for R ¹ . Examples of the substituent that the alkyl group of R ² has are the same as those of R ¹ described above.
In addition, the cycloalkyl group of R ² and the substituent that the cycloalkyl group has can be the same as those of R ¹ described above. Furthermore, the aryl group of R ² and the substituent that the aryl group has can be the same as those of R ¹ described above.

As the halogen atom and alkyl group for R ^3, the same groups as those described above for R ¹ can be used.
The substituent that the alkyl group as R ³ has is a cycloalkyl group, aryl group, amino group, amide group, ureido group, urethane group, hydroxyl group, carboxy group, halogen atom, alkoxy group, thioether group, acyl group, acyloxy group. , Alkoxycarbonyl group, cyano group, nitro group and the like.

The cycloalkyl group of R ³ and the substituent that the cycloalkyl group has can be the same as those of R ¹ described above. The aryl group of R ^{3 and} the substituent that the aryl group has can be the same as those of R ¹ described above.
In addition, examples of the alkoxy group for R ³ include the same groups as those described above for R ¹ .

The acyl group of R ^3, is not particularly limited, preferably an acyl group having 1 to 8 carbon atoms, e.g., formyl group, acetyl group, propionyl group, butyryl group, valeryl group, a pivaloyl group, include benzoyl group and the like It is done.

  x1 is an integer of 3-12, preferably an integer of 4-12, more preferably an integer of 4-8.

If the compound represented by the chemical formula (1) has an average of one or more phenolic hydroxyl groups in one molecule and an average of one or more groups represented by the chemical formula (I) in one molecule, The substituents indicated by the same reference numerals in each repeating unit may be the same or different. The positions of OR ² and R ³ in each repeating unit may be the same or different.

In the compound represented by the chemical formula (1), x1 is preferably 4 and n1 is preferably 2 from the viewpoint of obtaining a pattern with high sensitivity, high resolution, and good shape. 4, n1 is 2 and 8 R ² are preferably calix resorcinarene derivatives having 4 to 7 hydrogen atoms and 1 to 4 groups represented by the above chemical formula (I).

On the other hand, in the compound represented by the chemical formula (3), the alkyl group in R ⁶ , R ⁷ , R ⁸ and R ⁹ may be linear or branched, and is preferably a methyl group, an ethyl group, a propyl group, or butyl. And those having 1 to 10 carbon atoms such as a group, an isobutyl group, a hexyl group, and an octyl group.
The cycloalkyl group in R ⁶ , R ⁷ , R ⁸ and R ⁹ may be monocyclic or polycyclic. For example, groups having a monocyclo, bicyclo, tricyclo or tetracyclo structure having 5 or more carbon atoms can be given. The number of carbon atoms is preferably 6 to 30, and particularly preferably 7 to 25. For example, adamantyl group, noradamantyl group, decalin residue, tricyclodecanyl group, tetracyclododecanyl group, norbornyl group, cedrol Group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecanyl group, cyclododecanyl group and the like. These alicyclic hydrocarbon groups may have a substituent.
The aryl group in R ⁶ , R ⁷ , R ⁸ and R ⁹ may be the same as R ¹ described above.
In the compound represented by the chemical formula (3), R ⁶ is a (x2) -valent group when (x2) is an integer of 2 or more.

  Examples of the substituent that the alkyl group, cycloalkyl group, and aryl group may have include a hydroxyl group, a carboxyl group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom), an alkoxy group (a methoxy group, an ethoxy group, A propoxy group, a butoxy group, etc.), a hydroxymethyl group, or an alkoxymethyl group.

Examples of the monovalent organic group in R ¹⁰ and R ¹¹ include an alkyl group, an aryl group, an aralkyl group, an alkoxy group, an alkoxycarbonyl group, an amide group, a cyano group, and a vinyl ether group. The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms or a cycloalkyl group. For example, methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group, hexyl group, 2-ethylhexyl group, octyl Group, cyclopropyl group, cyclobutyl group, cyclohexyl group, adamantyl group and the like. The aryl group is preferably an aryl group having 6 to 14 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthracenyl group. The aralkyl group is preferably an aralkyl group having 6 to 12 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, and a cumyl group. The alkoxy group in the alkoxy group and the alkoxycarbonyl group is preferably an alkoxy group having 1 to 5 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, an n-butoxy group, and an isobutoxy group.

The alkylene group in W may be linear or branched, and preferably has 1 to 10 carbon atoms, and examples thereof include a methylene group, an ethylene group, a propylene group, a butylene group, and an isobutylene group.
The cycloalkylene group in W may be monocyclic or polycyclic, and examples of the alkylene group forming the ring include a cycloalkylene group having 3 to 8 carbon atoms (for example, a cyclopentylene group and a cyclohexylene group). be able to.
The alkylene group and cycloalkylene group in W may further have a substituent, and examples of the substituent include an alkyl group (preferably having a carbon number of 1 to 10, for example, methyl group, ethyl group, propyl group, isopropyl group, n -Butyl group, isobutyl group, sec-butyl group, t-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, etc.), alkoxy group (preferably having 1 to 4 carbon atoms, such as methoxy Group, ethoxy group, propoxy group, butoxy group, etc.), fluorine atom, chlorine atom, bromine atom, iodine atom and the like.

In addition, an alkylene chain or a cycloalkylene chain includes —O—, —OC (═O) —, —OC (═O) O—, —N (R) —C (═O) —, —N in the alkylene chain. (R) —C (═O) O—, —S—, —SO—, —SO ₂ — may be included. Here, R represents a hydrogen atom or an alkyl group (preferably having a carbon number of 1 to 10, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, pentyl group). Group, hexyl group, heptyl group, octyl group, nonyl group, decyl group and the like.
The cyclic arylene group in W is preferably a group having 6 to 15 carbon atoms such as a phenylene group, a tolylene group, and a naphthylene group.

  In the present invention, the phenol derivative mixture represented by the above chemical formula (1) (among others) is excellent in pattern strength, resists pattern collapse, and can obtain a pattern with high resolution and low line edge roughness. A) is preferred.

  Although the manufacturing method of the phenol derivative mixture (A) used for this invention is not specifically limited, For example, by using a phenolic compound as a precursor, some hydrogen of the phenolic hydroxyl group which the said phenolic compound has, and chemical formula (I) It can be obtained by substituting the group represented. As a method of substituting a part of hydrogen of the phenolic hydroxyl group and the group represented by the chemical formula (I), it can be obtained by a condensation reaction of a phenolic compound and a halogenated alkyl vinyl ether compound.

（化学式（Ｉ’）中、Ｒ^ａ〜Ｒ^ｄは、化学式（Ｉ）と同じであり、Ｘはハロゲン原子である。）

(In the chemical formula (I ′), R ^{a to} R ^d are the same as those in the chemical formula (I), and X is a halogen atom.)

  As the halogen atom in the chemical formula (I ′), a chlorine atom and a bromine atom are preferable.

  Although the specific example of the phenolic compound used as a precursor of a phenol derivative mixture (A) below is shown, this invention is not limited to these.

  The phenolic compound used as the precursor of the phenol derivative mixture (A) is commercially available from, for example, Honshu Chemical Industry Co., Ltd., Asahi Organic Materials Co., Ltd., and the like, and can be used. It can also be synthesized by condensation of various phenolic compounds with various aldehydes and ketones.

The phenolic compound used as the precursor of the phenol derivative mixture (A) may be used singly or in combination of two or more.
However, in the positive resist composition according to the present invention, the phenol derivative mixture (A) is such that the proportion of the phenol derivative obtained from the same phenolic compound is 70% by weight or more, thereby improving the low line edge roughness. The ratio of the phenol derivative obtained from the same phenolic compound is more preferably 80% by weight or more, and still more preferably 90% by weight or more.
Here, the phenol derivative obtained from the same phenolic compound includes a phenolic compound as a precursor and one or more phenol derivatives obtained from the phenolic compound. Each compound contained in a phenol derivative obtained from the same phenolic compound usually has the same chemical structure (host nucleus) excluding a substituent.
As the phenol derivative mixture (A), the higher the proportion of the phenol derivative obtained from the same phenolic compound as described above, the higher the compatibility, and the more uniform the development progress, so the line edge roughness is reduced. It is estimated that
However, the phenol derivative mixture (A) has a similar phenolic compound structure and good compatibility even if the ratio of the phenol derivative obtained from the same phenolic compound is less than the above value. Can be suitably used.

The content of the phenol derivative mixture (A) is 70% by weight or more, preferably 75% by weight or more, and more preferably 80% by weight or more based on the total solid content of the resist composition. . Moreover, since it contains the acid generator (B) mentioned later at least, it is preferable that an upper limit is 98 weight% or less with respect to the total solid of a resist composition.
In addition, in this invention, solid content means things other than an organic solvent among the components contained in a positive resist composition.

<Acid generator (B) that generates an acid directly or indirectly by irradiation with an active energy ray having a wavelength of 248 nm or less>
The acid generator (B) that generates an acid directly or indirectly by irradiating an active energy ray having a wavelength of 248 nm or less used in the present invention is a known acid used in a conventional chemically amplified resist composition. The generator can be used without particular limitation.

  The acid generator (B) is preferably at least one selected from the group consisting of compounds represented by the following chemical formulas (4) to (9).

In chemical formula (4), R ¹² may be the same or different and each independently represents a hydrogen atom, a linear alkyl group having 1 to 12 carbon atoms, a branched alkyl group having 3 to 12 carbon atoms, or a carbon number. C3-C12 cyclic alkyl group, C1-C12 linear alkoxy group, C3-C12 branched alkoxy group, C3-C12 cyclic alkoxy group, C5-C10 branched alkoxy A carbonylalkoxy group, a hydroxyl group, or a halogen atom, and X ⁻ represents an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, a halogen-substituted alkyl group having 1 to 12 carbon atoms, or 6 to 6 carbon atoms. A sulfonate ion or a halide ion having 12 halogen-substituted aryl groups. n is an integer of 0-5.

  Examples of the compound represented by the chemical formula (4) include triphenylsulfonium trifluoromethylsulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium cyclohexafluoropropane-1,3-bis (sulfonyl). Imido, triphenylsulfonium nonafluorobutanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, diphenyl-4-methylphenylsulfonium trifluoromethanesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium trifluoromethanesulfonate, diphenyl-2 , 4,6-Trimethylphenylsulfonium p-toluenesulfonate, diphenyl-4-t-butoxyphenylsulfonium Fluoromethanesulfonate, diphenyl-4-t-butoxyphenylsulfonium nonafluoro-n-butanesulfonate, diphenyl-4-hydroxyphenylsulfonium trifluoromethanesulfonate, bis (4-fluorophenyl) -4-hydroxyphenylsulfonium trifluoromethanesulfonate, diphenyl 3,5-dimethyl-4-hydroxyphenylsulfonium nonafluoro-n-butanesulfonate, diphenyl-4-hydroxyphenylsulfonium nonafluoro-n-butanesulfonate, bis (4-hydroxyphenyl) -phenylsulfonium trifluoromethanesulfonate, bis (4-hydroxyphenyl) -t-pentylphenylsulfonium trifluoromethanesulfonate, tris (4 Methoxyphenyl) sulfonium trifluoromethanesulfonate, tris (4-fluorophenyl) sulfonium trifluoromethanesulfonate, triphenylsulfonium-p-toluenesulfonate, triphenylsulfoniumbenzenesulfonate, diphenyl-2,4,6-trimethylphenyl-p-toluenesulfonate Diphenyl-2,4,6-trimethylphenylsulfonium-2-trifluoromethylbenzenesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium-4-trifluoromethylbenzenesulfonate, diphenyl-2,4,6-trimethyl Phenylsulfonium-2,4-difluorobenzenesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium hexafluor Benzenesulfonate, diphenylnaphthylsulfonium trifluoromethanesulfonate, diphenyl-4-hydroxyphenylsulfonium-p-toluenesulfonate, triphenylsulfonium 10-camphorsulfonate, diphenyl-4-hydroxyphenylsulfonium 10-camphorsulfonate, (4-t-butoxycarbonyl) Methoxyphenyl) diphenylsulfonium-4-trifluoromethylbenzenesulfonate, 2,4-di (t-butoxycarbonylmethoxy) phenyldiphenylsulfonium-4-trifluoromethylbenzenesulfonate, (4-t-butoxycarbonylmethoxyphenyl) diphenylsulfonium -2,4,6-tris (trifluoromethyl) benzenesulfonate, 2,4-di ( and t-butoxycarbonylmethoxy) phenyldiphenylsulfonium-2,4,6-tris (trifluoromethyl) benzenesulfonate.

In chemical formula (5), X ⁻ , R ¹³ , and n are the same as X ⁻ , R ¹² , and n in chemical formula (4).

  Examples of the compound represented by the chemical formula (5) include bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4 -T-butylphenyl) iodonium perfluoro-n-octanesulfonate, bis (4-t-butylphenyl) iodonium p-toluenesulfonate, bis (4-t-butylphenyl) iodoniumbenzenesulfonate, bis (4-t-butyl) Phenyl) iodonium-2-trifluoromethylbenzenesulfonate, bis (4-t-butylphenyl) iodonium-4-trifluoromethylbenzenesulfonate, bis (4-t-butylphenyl) iodonium-2,4-difluorobenzenes Phonate, bis (4-t-butylphenyl) iodonium hexafluorobenzenesulfonate, bis (4-t-butylphenyl) iodonium 10-camphorsulfonate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium Perfluoro-n-octanesulfonate, diphenyliodonium p-toluenesulfonate, diphenyliodoniumbenzenesulfonate, diphenyliodonium10-camphorsulfonate, diphenyliodonium-2-trifluoromethylbenzenesulfonate, diphenyliodonium-4-trifluoromethylbenzenesulfonate, diphenyl Iodonium-2,4-difluorobenze Sulfonate, diphenyliodonium hexafluorobenzenesulfonate, bis (4-trifluoromethylphenyl) iodonium trifluoromethanesulfonate, bis (4-trifluoromethylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-trifluoromethylphenyl) Iodonium perfluoro-n-octanesulfonate, bis (4-trifluoromethylphenyl) iodonium p-toluenesulfonate, bis (4-trifluoromethylphenyl) iodoniumbenzenesulfonate, bis (4-trifluoromethylphenyl) iodonium 10-camphor Examples include sulfonates.

In chemical formula (6), A is an alkylene group having 1 to 12 carbon atoms, an arylene group having 6 to 12 carbon atoms, or an alkyleneoxy group having 1 to 12 carbon atoms (—R′—O—, where R ′ is carbon. R ¹⁴ is an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, a halogen-substituted alkyl group having 1 to 12 carbon atoms, or a C 6 to 12 carbon group. A halogen-substituted aryl group.

  Examples of the compound represented by the chemical formula (6) include N- (trifluoromethylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) phthalimide, N- (trifluoromethylsulfonyloxy) diphenylmaleimide, N -(Trifluoromethylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) naphthylimide, N- (10-camphorsulfonyl) Oxy) succinimide, N- (10-camphorsulfonyloxy) phthalimide, N- (10-camphorsulfonyloxy) diphenylmaleimide, N- (10-camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene -2,3-dicarboxyimi N- (10-camphorsulfonyloxy) naphthylimide, N- (n-octanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (n -Octanesulfonyloxy) naphthylimide, N- (p-toluenesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (p-toluenesulfonyloxy) naphthyl Imido, N- (2-trifluoromethylbenzenesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (2-trifluoromethylbenzenesulfonyloxy) naphthyl Imido, N- (4-trifluoromethylbenzenesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboxyl Imido, N- (4-trifluoromethylbenzenesulfonyloxy) naphthylimide, N- (perfluorobenzenesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N -(Perfluorobenzenesulfonyloxy) naphthylimide, N- (1-naphthalenesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (1-naphthalenesulfonyl) Oxy) naphthylimide, N- (nonafluoro-n-butanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (nonafluoro-n-butanesulfonyloxy) Naphthylimide, N- (perfluoro-n-octanesulfonyloxy) bicyclo [2.2.1] hept-5-e 2,3-dicarboximide, N- (perfluoro--n- octane sulfonyloxy) naphthylimide, and the like.

In chemical formula (7), R ¹⁵ may be the same or different and each independently represents a linear alkyl group having 1 to 12 carbon atoms, a branched alkyl group having 3 to 12 carbon atoms, or 3 to 12 carbon atoms. A cyclic alkyl group, an aryl group having 6 to 12 carbon atoms, a heteroaryl group having 3 to 12 carbon atoms, or an aralkyl group having 7 to 12 carbon atoms. Each of the substituents may be substituted with an alkyl group having 1 to 12 carbon atoms, a hydroxyl group, a halogen atom, or a haloalkyl group having 1 to 12 carbon atoms.

  Examples of the compound represented by the chemical formula (7) include diphenyl disulfone, di (4-methylphenyl) disulfone, dinaphthyl disulfone, di (4-t-butylphenyl) disulfone, and di (4-hydroxyphenyl). ) Disulfone, di (3-hydroxynaphthyl) disulfone, di (4-fluorophenyl) disulfone, di (2-fluorophenyl) disulfone, di (4-trifluoromethylphenyl) disulfone and the like.

In chemical formula (8), R ¹⁶ may be the same or different and each independently represents a linear alkyl group having 1 to 12 carbon atoms, a branched alkyl group having 3 to 12 carbon atoms, or 3 to 12 carbon atoms. A cyclic alkyl group, an aryl group having 6 to 12 carbon atoms, a heteroaryl group having 3 to 12 carbon atoms, or an aralkyl group having 7 to 12 carbon atoms. Each of the substituents may be substituted with an alkyl group having 1 to 12 carbon atoms, a halogen atom, or an alkoxy group having 1 to 12 carbon atoms.

  Examples of the compound represented by the chemical formula (8) include α- (methylsulfonyloxyimino) -phenylacetonitrile, α- (methylsulfonyloxyimino) -4-methoxyphenylacetonitrile, α- (trifluoromethylsulfonyloxy). Imino) -phenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -4-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -4-methoxyphenylacetonitrile, α- (propylsulfonyloxyimino) -4-methyl Examples include phenylacetonitrile and α- (methylsulfonyloxyimino) -4-bromophenylacetonitrile.

In chemical formula (9), R ¹⁷ may be the same or different and each independently represents a halogenated alkyl group having one or more chlorine atoms and one or more bromine atoms. The halogenated alkyl group preferably has 1 to 5 carbon atoms.

  Examples of the compound represented by the chemical formula (9) include monochloroisocyanuric acid, monobromoisocyanuric acid, dichloroisocyanuric acid, dibromoisocyanuric acid, trichloroisocyanuric acid, and tribromoisocyanuric acid. .

  Examples of the other acid generator (B) include bis (p-toluenesulfonyl) diazomethane, bis (2,4-dimethylphenylsulfonyl) diazomethane, bis (t-butylsulfonyl) diazomethane, and bis (n-butylsulfonyl). Bissulfonyldiazomethanes such as diazomethane, bis (isobutylsulfonyl) diazomethane, bis (isopropylsulfonyl) diazomethane, bis (n-propylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, 2- (4-methoxyphenyl) -4,6 -(Bistrichloromethyl) -1,3,5-triazine, 2- (4-methoxynaphthyl) -4,6- (bistrichloromethyl) -1,3,5-triazine, tris (2,3-dibromopropyl) ) -1,3,5-triazine, And halogen-containing triazine derivatives such as tris (2,3-dibromopropyl) isocyanurate.

These acid generators (B) may be used individually by 1 type, and may be used in combination of 2 or more type.
The content of the acid generator (B) is preferably 2 to 30% by weight, more preferably 4 to 20% by weight, based on the total solid content of the resist composition. If the amount is less than this range, image formation may not be possible. On the other hand, when it exceeds this range, a uniform solution is not obtained and storage stability may be lowered.

<Organic basic compound (C)>
Since the positive resist composition of the present invention contains the acid generator (B), an organic basic compound (C) is further used in order to improve the resist pattern shape, stability over time in storage conditions, and the like. Is preferred. The organic basic compound (C) can be selected from any known organic basic compounds.

  Examples of the organic basic compound (C) include nitrogen-containing organic compounds, such as nitrogen-containing compounds having a nitrogen atom, amide group-containing compounds, urea compounds, and nitrogen-containing heterocyclic compounds. It is not limited to these. These nitrogen-containing organic compounds include compounds containing polar groups such as ether bonds, carbonyl bonds, ester bonds, carbonate bonds, sulfide bonds, sulfone bonds, and the like, ester groups, acetal groups, cyano groups, alkoxy groups, A compound containing a polar group such as a hydroxyl group as a substituent is also preferably used.

  Examples of the nitrogen-containing organic compound include mono (cyclo) alkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, n-dodecylamine, cyclohexylamine; -N-butylamine, di-n-pentylamine, di-n-hexylamine, di-n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine, methyl-n-dodecyl Di (cyclo) alkylamines such as amine, di-n-dodecylmethylamine, cyclohexylmethylamine, dicyclohexylamine; triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri- n-hexylamine, tri-n-heptylamine, tri-n- Tri (cyclo) alkylamines such as cutylamine, tri-n-nonylamine, tri-n-decylamine, dimethyl-n-dodecylamine, di-n-dodecylmethylamine, dicyclohexylmethylamine, tricyclohexylamine; monoethanolamine, Alkanolamines such as diethanolamine and triethanolamine; aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, triphenylamine , Aromatic amines such as tribenzylamine, 1-naphthylamine; ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylene Amine, tetramethylenediamine, hexamethylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 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 -Methylethyl] benzene, polyethyleneimine, 2,2- (phenylimino) diethanol, polyallylamine, N- (2 Dimethylaminoethyl) acrylamide polymer, tris (2-acetoxyethyl) amine, tris (2-pivaloyloxyethyl) amine, tris (2-t-butoxycarbonyloxyethyl) amine, tris [2- (2- Oxopropoxy) ethyl] amine, tris [2- (methoxycarbonylmethyl) oxyethyl] amine, tris [2- (t-butoxycarbonylmethyloxy) ethyl] amine, tris [2- (2-methoxyethoxy) ethyl] amine, N- [2- (methylsulfonyl) ethyl] diethanolamine, N- [2- (methylsulfonyl) ethyl] bis (2-acetoxyethyl) amine, N- [2- (methylsulfonyl) ethyl] bis (2-formyloxy) Ethyl) amine, N- [2- (methylsulfonyl) ethyl] bi (2-methoxyethyl) amine, 3,3 ′-[2- (methylsulfonyl) ethyl] iminodipropionic acid dimethyl, N- (tetrahydrofurfuryl) bis [2- (methylsulfonyl) ethyl] amine, 3- Examples include t-butyl [bis (2-methoxyethyl) amino] propionate, t-butyl 3- [bis (2-acetoxyethyl) amino] propionate, and the like.

  Examples of the amide group-containing compound include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone and the like. 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, benzimidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole, 2-phenylbenzimidazole, 4,5-diphenylimidazole, 2,4,5-trimethyl. Imidazoles such as phenylimidazole; pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4-phenylpyridine, nicotine, Pyridines such as nicotinic acid, nicotinic amide, quinoline, 8-oxyquinoline, acridine; and pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, morpholine, 4-methylmorpholine, piperazine, 1,4-dimethylpipe Razine, 1,4-diazabicyclo [2.2.2] octane, 1- [2- (methoxymethoxy) ethyl] pyrrolidine, 1- [2- (2-methoxyethoxy) methoxy] ethyl] pyrrolidine, 1- [2 -(2-methoxyethoxy) methoxy] ethyl] piperidine, 4- [2- (methoxymethoxy) ethyl] morpholine, 4- [2- (2-methoxyethoxy) methoxy] ethyl] morpholine 1- (2 ', 3' -Dihydroxypropyl) -2-methylimidazole, 1,3-di (2'-methyl-1'-imidazolylmethyl) benzene, 1-benzyl-2-methylimidazole, 1-benzylimidazole, acetic acid 2- (1H -Benzimidazol-1-yl) ethyl, 2- (2-phenyl-1H-benzimidazol-1-yl) ethyl acetate, 3- (2- Enyl-1H-benzimidazol-1-yl) methyl propionate, 1- [2- (1,3-dioxolan-2-yl) ethyl] 1H-benzimidazole, 4- (1H-benzimidazol-1-yl) Examples include butyronitrile, t-butyl 3-morpholinopropionate, t-butyl 3-piperidinopropionate, 1-ethylcyclopentyl 3-piperidinopropionate, 1-ethyl 2-norbornyl 3-piperidinopropionate, and the like. It is done.

  These organic basic compounds (C) can be used alone or in combination of two or more. The compounding amount of the organic basic compound (C) is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the phenol derivative mixture (A). If it is less than 0.01 part by weight, the effect of the addition may not be obtained. On the other hand, when it exceeds 10 parts by weight, the sensitivity is lowered and the developability of the unexposed part tends to deteriorate.

<Other ingredients>
An oligomer or polymer component for improving the performance of the resist film may be added to the positive resist composition of the present invention within a range where the effects of the present invention are not impaired. By adding an oligomer or polymer component and introducing a network structure in the resist film, resolution may be improved by improving pattern strength, and pattern shape (line edge roughness) may be improved. The content of such an oligomer or polymer component is preferably 5% by weight or less, more preferably 3% by weight or less, based on the total solid content of the resist composition.
The oligomer or polymer component is derived from a novolak resin, a polyhydroxystyrene derivative, acrylic acid or methacrylic acid, which is an alkali developable resin conventionally used in positive resist compositions for i-line, KrF, and ArF. An acrylic copolymer. These oligomer or polymer components may have a reactive functional group.
The weight average molecular weight of the oligomer or polymer component is preferably 2000 to 30000, and more preferably 2000 to 20000. The weight average molecular weight here refers to a polystyrene equivalent value measured by a GPC (gel permeation chromatography) method.

  In the positive resist composition of the present invention, as long as the effects of the present invention are not impaired, additives that are miscible as desired, for example, additional resins for improving the performance of the resist film, in order to improve coatability. These surfactants, dissolution inhibitors, plasticizers, stabilizers, colorants, antihalation agents, and the like can be added and contained as appropriate.

<Preparation of positive resist composition>
The positive resist composition according to the present invention is usually prepared by uniformly mixing the above-described phenol derivative mixture (A) and other additives as required in an organic solvent.

As the organic solvent, those generally used as resist solvents can be used. For example, ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, Propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether propionate, diethylene glycol dimethyl ether, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N-dimethylformamide, dimethyl sulfoxide N- methylpyrrolidone, tetrahydrofuran and the like are preferred, it is possible to use these solvents singly or in combination. Further, isopropyl alcohol, ethyl alcohol, methyl alcohol, n-butyl alcohol, s-butyl alcohol, t-butyl alcohol, isobutyl alcohol, 2-methyl-1-pentanol, 4-methyl-2-pentanol, 2-methoxyethanol , 2-ethoxyethanol, 1-ethoxy-2-propanol, 1-methoxy-2-propanol and other alcohols, and toluene, xylene and other aromatic solvents may be contained.
In the present invention, among these organic solvents, in addition to diethylene glycol dimethyl ether, cyclohexanone, cyclopentanone, 1-ethoxy-2-propanol, and ethyl lactate, safety solvents such as propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and mixed solvents thereof Are preferably used.
The amount of the solvent in the resist composition is not particularly limited, and is a concentration that can be applied to a substrate or the like, and is appropriately set according to the coating film thickness. Generally, the solvent is used so that the solid content concentration of the resist composition is preferably in the range of 0.5 to 20% by weight, more preferably 0.5 to 15% by weight.

  In the positive resist composition according to the present invention, the water content is preferably adjusted to 0.5% by weight or less, more preferably 0.01 to 0.5% by weight, and still more preferably 0.15 to 0.30% by weight. . The water content can be adjusted, for example, by appropriately drying the material used or by drying the preparation atmosphere (for example, humidity of 50% or less).

In the positive resist composition according to the present invention, the acid component content is preferably adjusted to 1 × 10 ⁻³ meq / g or less, more preferably 5 × 10 ⁻⁴ meq / g or less. The acid component content can be adjusted, for example, by treating a solution of the used material or a composition solution with an ion exchange resin, or washing the solution of the used material with pure water. The acid component content can be determined by non-aqueous potential difference measurement.
The positive resist composition according to the present invention is preferably used after being prepared and filtered.

  The positive resist composition of the present invention is suitably used in a microlithography process for producing miniaturized electronic components such as for forming a gate layer of a semiconductor integrated circuit and for processing a mask pattern formed on a glass substrate. can do.

  The present invention also provides an electronic component that is at least partially formed from the positive resist composition according to the present invention or a cured product thereof. In the electronic component according to the present invention, if the positive resist composition or the cured product thereof according to the present invention is included in any of the configurations including the resist composition or the cured product thereof, other configurations are conventionally known. It can be similar. Examples of the electronic component according to the present invention include a MEMS (micro electro mechanical device) component, a micro mechanical component, a micro fluid engineering component, a μ-TAS (micro total analysis device) component, an inkjet printer component, a micro reactor component, Electrically conductive layers, metal bump connections, LIGA (lithography electroforming) parts, molds and molds for micro injection molding and micro coining, precision printing screens or stencils, MEMS and semiconductor package parts, and ultraviolet ( Examples thereof include a printed wiring board that can be processed by UV) lithography.

II. Manufacturing method of relief pattern The manufacturing method of the relief pattern according to the present invention,
(I) a step of applying a positive resist composition according to the present invention on a substrate and then heat-treating to form a resist film; and (ii) applying the resist film to an electron beam, ion beam, EUV, or X-ray. The process of exposing and developing in
It is characterized by including.

  According to the method for producing a relief pattern according to the present invention, an alkali development is possible, and a pattern having a good shape can be formed with a high resolution.

Hereinafter, each step will be described.
(I) Step of applying a positive resist composition according to the present invention on a substrate and then heat-treating to form a resist film In this step, first, the above positive resist composition is applied on a substrate. .
The coating method is not particularly limited as long as it is a method capable of uniformly coating the positive resist composition on the substrate surface, and various methods such as a spray method, a roll coating method, a slit coating method, and a spin coating method. Can be used.

Next, the positive resist composition applied on the substrate is pre-baked (PAB), the organic solvent is removed, and a resist film is formed. At this time, the phenolic hydroxyl group in the phenol derivative mixture (A) in the resist is bonded to the group represented by the chemical formula (I), and the phenol derivative mixture (A) is linked.
The pre-baking temperature may be appropriately determined depending on the components of the composition, the use ratio, the type of the organic solvent, and the like, and is usually 80 to 160 ° C., preferably 90 to 150 ° C. The pre-bake time is usually about 30 seconds to 15 minutes.

(Ii) Step of exposing and developing the resist film with an electron beam, ion beam, EUV, or X-ray In this step, first, the resist film is exposed to, for example, an electron beam lithography apparatus, an EUV exposure apparatus, or the like. Using the apparatus, exposure is selectively performed by exposure through a mask having a predetermined pattern shape, drawing by direct irradiation of an electron beam without passing through the mask, or the like.
The exposure light source is not particularly limited, and is performed using an ArF excimer laser, a KrF excimer laser, an F ₂ excimer laser, EUV (Extreme Ultraviolet), an electron beam, an X-ray, an ion beam such as helium or hydrogen. Can do.

  Next, after the exposure, post-exposure heating (Post Exposure Bake, PEB) is performed. The PEB treatment is usually performed at a temperature of 50 to 160 ° C. for a time of about 0.1 to 15 minutes.

Next, the substrate subjected to the PEB treatment is developed using an alkali developer, and the irradiated portion of the exposure light is removed.
Examples of the developing method include a spray method, a slit method, a liquid piling method, a dipping method, and a rocking dipping method.
Examples of the alkaline developer of the positive resist composition of the present invention include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, and n-propylamine. Primary amines such as diethylamine, secondary amines such as di-n-butylamine, tertiary amines such as triethylamine and methyldimethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxy An aqueous solution of an alkali such as quaternary ammonium salts such as copper, tetraethylammonium hydroxide, tetrabutylammonium hydroxide and choline, and cyclic amines such as pyrrole and piperidine can be used. Furthermore, an appropriate amount of an alcohol such as isopropyl alcohol or a nonionic surfactant may be added to the alkaline aqueous solution. Among these alkaline developers, a quaternary ammonium salt is preferable, and an aqueous solution of tetramethylammonium hydroxide and choline is more preferable.

  When a tetramethylammonium hydroxide (TMAH) aqueous solution is used as the alkali developer, the concentration of the tetramethylammonium hydroxide aqueous solution is preferably 0.1% to 25%, more preferably 0.2%. -5%, particularly preferably 0.2% -2.38%. 2.38% concentration of tetramethylammonium hydroxide aqueous solution is generally most readily available in the semiconductor industry. In addition, when the concentration of the tetramethylammonium hydroxide aqueous solution is less than 0.1%, the developer is neutralized by carbon dioxide in the air, and the sensitivity fluctuates, making it difficult to stably obtain a product. Become.

  After the development treatment, a rinsing treatment is performed, and the alkali developer on the substrate and the resist composition dissolved by the alkali developer are washed away and dried to obtain a resist pattern.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effects. Are included in the technical scope.

Hereinafter, the present invention will be specifically described with reference to examples. These descriptions do not limit the present invention.
In addition, the structure and physical properties in the production examples were confirmed using the following apparatuses.
¹ H-NMR: JEOL JNM-LA400WB, manufactured by JEOL Ltd.
Glass transition temperature (Tg): Using a differential thermal analyzer (“DSC-60” manufactured by Shimadzu Corporation), about 4 mg of the pattern forming material was heated to 200 ° C. at a rate of 10 ° C./min, cooled to room temperature, and then again. The glass transition temperature was defined as the intersection of both tangents of the smooth curve before and after the inflection temperature part of the DTA curve when the temperature was raised to 200 ° C. at a rate of 10 ° C./min. When the inflection point of the DTA curve corresponding to the glass transition temperature was not observed by 200 ° C., Tg was determined to be 200 ° C. or higher.

<Comparative Synthesis Example 1: Synthesis of phenolic compound>
Under a nitrogen atmosphere, in a 300 mL three-necked flask, 25.2 g (230 mmol) of resorcinol was dissolved in 100 mL of a mixed solution of ethanol: water = 1: 1. While cooling this in an ice bath, 12.2 mL (220 mmol) of acetaldehyde was added, and then 21 mL of concentrated hydrochloric acid was slowly added dropwise and reacted at 75 ° C. for 1 hour. After completion of the reaction, the reaction solution was poured into 300 mL of distilled water, and the resulting precipitate was filtered and washed with distilled water until neutral. Purification of the filtered solid was recrystallized with a mixed solvent of methanol / water, and 21.6 g (39.7 mmol, yield 73.0%) of a phenolic compound (CRA-1) represented by the following chemical formula (10) )

<Synthesis Example 1: Synthesis of phenol derivative mixture (A)>
0.36 g (15 mmol) of sodium hydride, 14 mL of N-methylpyrrolidone (NMP), 1.4 g (2.5 mmol) of the phenolic compound (CRA-1) obtained in Comparative Synthesis Example 1, tetrabutylammonium After adding 0.08 g (0.25 mmol) of bromide and stirring for a while, 1.5 mL (15 mmol) of chloroethyl vinyl ether was added and stirred at 80 ° C. for 16 hours. Thereafter, 150 mL of a 2.38 wt% TMAH aqueous solution was added and stirred for a while, then diethyl ether was added and only the aqueous phase was taken out. Ethyl acetate was added to this aqueous phase, and further neutralized by adding a 5 wt% aqueous citric acid solution, followed by washing three times with pure water, adding magnesium sulfate and drying, and the ethyl acetate was distilled off. Chloroform was added thereto, and after dissolving the solid, hexane was added and stirred for a while, and the solvent was distilled off. This operation was repeated twice and then dried under reduced pressure to obtain 1.08 g (1.47 mmol, yield 58.8%) of a phenol derivative mixture (A-1) represented by the following chemical formula (11). The introduction amount of the group represented by the above chemical formula (I) was calculated by ¹ H-NMR spectrum. In the phenol derivative mixture (A-1), the average number of phenolic hydroxyl groups was 5.12, and the number of groups represented by the chemical formula (I) was 2.88. Glass transition temperature: 200 ° C or higher

化学式（１１）中、Ｒの３６％がエチルビニルエーテル基、６４％が水素原子であった。

In the chemical formula (11), 36% of R was an ethyl vinyl ether group, and 64% was a hydrogen atom.

<Synthesis Example 2: Synthesis of Phenol Derivative Mixture (A)>
The amount of each compound added in Synthesis Example 1 was 0.18 g (7.5 mmol) of sodium hydride, 14.0 mL of NMP, and 1.4 g of phenolic compound (CRA-1) obtained in Comparative Synthesis Example 1 (2. 5 mmol), 0.08 g (0.25 mmol) of tetrabutylammonium bromide, and 0.75 mL (7.5 mmol) of chloroethyl vinyl ether, and represented by the following chemical formula (12) in the same manner as in Synthesis Example 1. 0.93 g (1.43 mmol, yield 57.0%) of compound (A-2) was obtained. The introduction amount of the group represented by the above chemical formula (I) was calculated by ¹ H-NMR spectrum. In the phenolic derivative mixture (A-2), the average number of phenolic hydroxyl groups was 6.48, and the number of groups represented by the chemical formula (I) was 1.52. Glass transition temperature: 200 ° C or higher

化学式（１２）中、Ｒの１９％がエチルビニルエーテル基、８１％が水素原子であった。

In the chemical formula (12), 19% of R was an ethyl vinyl ether group and 81% was a hydrogen atom.

<Comparative Synthesis Example 2: Synthesis of a phenolic compound having a protective group introduced>
In a solution consisting of 2.7 g (5 mmol) of the phenolic compound (CRA-1) obtained in Comparative Synthesis Example 1, 0.12 g (0.1 mmol) of 4- (dimethylamino) pyridine and acetone (20 mL), 6. 2 mL (28 mmol) bis (tert-butoxycarbonyl) oxide was added dropwise. The reaction was stirred for 60 minutes at room temperature to evaporate the solution. Using a mixed solvent of hexane / ethyl acetate = 1/1 as a developing solvent and purifying by column chromatography, 95% of a phenol compound (CA-1) in which a phenolic hydroxyl group is substituted with a tert-butoxycarbonyl group is obtained. Obtained in yield. ^{From the 1} H and ¹³ C-NMR spectra, the protection ratio for all phenolic hydroxyl groups was 68%.

化学式（１３）中、Ｐの６８％がｔｅｒｔ−ブトキシカルボニル基、３２％が水素原子であった。

In the chemical formula (13), 68% of P was a tert-butoxycarbonyl group, and 32% was a hydrogen atom.

<Comparative Synthesis Example 3: Synthesis of Crosslinkable Compound>
To an NMP solution (20 mL) of 1,1,1-tris (4-hydroxyphenyl) ethane (1.0 g, 3.26 mmol) was added K ₂ CO ₃ (2.76 g, 20.0 mmol) and 2-chloroethyl vinyl ether ( 1.25 g, 11.74 mmol) was added, and the mixture was stirred at 75 ° C. for 15 hours under a nitrogen atmosphere. After completion of the reaction, the reaction solution was poured into distilled water to obtain a precipitate. Moreover, it was dissolved in acetone and reprecipitated in distilled water to obtain a white solid. The obtained solid was vacuum-dried at 80 ° C. for 12 hours to obtain a compound (D-1) (1.62 g, yield 96%) represented by the following chemical formula (14).

[Example: Preparation of positive resist composition]
A phenol derivative mixture (A) or a phenolic compound, an acid generator (B), an organic basic compound (C), a crosslinkable compound, and an organic solvent are made into uniform solutions with the blending amounts shown in Table 1, The sample solution was filtered through a 0.1 μm Teflon (registered trademark) filter to prepare positive resist compositions of Examples 1 and 2 and Comparative Examples 1 and 2.

The abbreviations in Table 1 are as follows.
B-1: Triphenylsulfonium trifluoromethylsulfonate B-2: Diphenyl-2,4,6-trimethylphenylsulfonium p-toluenesulfonate C-1: Tri-n-octylamine E-1: Cyclopentanone

[Preparation and evaluation method of resist pattern]
Using the positive resist compositions of Examples 1 and 2 and Comparative Examples 1 and 2, resist patterns were prepared and evaluated by the following methods.

(1) Application of resist Each resist composition was uniformly applied on a 6-inch silicon substrate using a spinner, and pre-baked (PAB) at 120 ° C. for 180 seconds to form a 300 nm-thick resist film. . In Comparative Example 2, a pre-baking process (PAB) was performed at 100 ° C. for 60 seconds because no crosslinking reaction was required during pre-baking.

(2) Preparation of resist pattern Drawing was performed on the resist film obtained in (1) using an electron beam drawing apparatus (acceleration voltage 100 kV). After the drawing, the film was baked (PEB) at 100 ° C. for 60 seconds, developed with a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution (23 ° C.) for 60 seconds, and purified with pure water for 60 seconds. A rinse treatment was performed for 2 seconds to form a line and space (L / S) pattern.

<Evaluation of resist pattern>
The following (1) and (2) were evaluated for each of the resist patterns obtained using the positive resist compositions of Examples 1 and 2 and Comparative Examples 1 and 2. The results are shown in Table 2.

(1) Sensitivity, resolution and LER
Sensitivity was measured in units of μC / cm ² with the minimum dose formed at a line width of 300 nm (line / space = 1: 1) as sensitivity. The smaller the value, the higher the sensitivity. Further, the limit resolution (the line and space are separated and resolved) at the irradiation amount was defined as the resolution. The confirmation of resolution was judged by a length measurement SEM (manufactured by Holon). The smaller the value, the higher the resolution. For LER, 500 points of line width were measured for a range of edge of 2.0 μm in the longitudinal direction of an L / S pattern of 300 nm, a standard deviation was obtained, and 3σ was calculated. Since the LER reflects the size of the irregularities on the pattern side wall, it is desirable that the numerical value is smaller.

(2) Pattern intensity The pattern intensity is determined by observing a part with a line width of 100 nm (line / space = 1: 1) with a side length SEM (manufactured by Holon Co., Ltd.) in a 3 μm square, and the number of pattern collapses in the visual field did.
A: No pattern collapse B: 1 to 4 pattern collapses C: 5 or more pattern collapses

[Summary of results]
The positive resist composition of Comparative Example 1 containing a phenolic compound and a crosslinkable compound is excellent in sensitivity and resolving power, but has a poor LER because it uses a mixture of a phenolic compound and a crosslinkable compound. Met.
In the positive resist composition of Comparative Example 2 using a resist base material in which a tert-butoxycarbonyl group is introduced as a protecting group in a part of a low molecular weight phenolic compound, the molecular weight of the base material is low, so the pattern collapses. There was a problem in the pattern strength.
Contains a phenol derivative mixture (A) having an average molecular weight of 400 to 2500 having an average of one or more phenolic hydroxyl groups in one molecule and an average of one or more groups represented by the chemical formula (I) in one molecule. It was found that the positive resist compositions of Examples 1 and 2 were excellent in pattern strength, resisted pattern collapse, and were able to obtain a pattern with high resolution and low line edge roughness.

Claims (8)

A phenol derivative mixture (A) having an average molecular weight of 400 to 2500 having an average of one or more phenolic hydroxyl groups in one molecule and an average of one or more groups represented by the following chemical formula (I) in one molecule, and A positive resist composition comprising an acid generator (B) that generates an acid directly or indirectly by irradiation with an active energy ray having a wavelength of 248 nm or less.

(In the chemical formula (I), R ^{a to} R ^c each independently represents a hydrogen atom, an alkyl group, or a cycloalkyl group, and two of R ^{a to} R ^c are bonded to form 3 to 8 carbon atoms or A ring structure composed of heteroatoms may be formed, and R ^d is a group selected from the group consisting of linear or branched alkylene groups having 1 to 6 carbon atoms, cycloalkylene groups, and combinations thereof.   2. The positive type according to claim 1, wherein the phenol derivative mixture (A) has a development rate of 0.5 nm / sec or more with respect to an aqueous solution of tetramethylammonium hydroxide (TMAH) having a concentration of 2.38 wt% at 23 ° C. 3. Resist composition.   3. The positive resist composition according to claim 1, wherein the phenol derivative mixture (A) has a structure in which hydrogen of a phenolic hydroxyl group is substituted with a group represented by the chemical formula (I).   The positive resist composition according to claim 1, further comprising an organic basic compound (C). The positive resist composition according to claim 1, wherein the phenol derivative mixture (A) is a phenol derivative mixture represented by the following chemical formula (1).

[In the chemical formula (1), R ¹ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, and a group selected from the group consisting of groups represented by the following chemical formula (2), the R ¹ The aryl group contained may have a hydroxyl group and / or a group represented by the following chemical formula (I).

(In the chemical formula (2), R ⁴ and R ⁵ are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, Q is an aryl group or a cycloalkyl group, and m is 1 or 2. Represents.)
R ^{2 s} are each independently a hydrogen atom or a monovalent organic group, and among the plurality of R ² , one or more on average in one molecule is a hydrogen atom, and one or more on average in one molecule is represented by the following chemical formula ( It is a group represented by I). R ³ is a group selected from the group consisting of halogen atoms, alkyl groups, cycloalkyl groups, aryl groups, alkoxy groups, acyl groups, cyano groups, nitro groups, hydroxymethyl groups, and alkoxymethyl groups.

(In the chemical formula (I), R ^{a to} R ^c each independently represents a hydrogen atom, an alkyl group, or a cycloalkyl group, and two of R ^{a to} R ^c are bonded to form 3 to 8 carbon atoms or A ring structure composed of heteroatoms may be formed, and R ^d is a group selected from the group consisting of linear or branched alkylene groups having 1 to 6 carbon atoms, cycloalkylene groups, and combinations thereof.
n1 represents an integer of 1 to 3, and n2 represents an integer of 0 to 2. However, a combination satisfying n1 + n2 ≦ 4 is selected from a numerical range of n1 and n2. x1 represents the integer of 3-12.
In addition, the groups represented by the same symbols included in the chemical formula (1) may be the same as or different from each other. ]   The positive resist composition according to any one of claims 1 to 5, wherein the phenol derivative mixture (A) has a glass transition temperature (Tg) of 60 ° C or higher. (I) a step of applying the positive resist composition according to any one of claims 1 to 6 on a substrate and then heat-treating to form a resist film; and (ii) forming the resist film with an electron beam, an ion A method for producing a relief pattern, comprising exposing, heating, and developing with a beam, EUV, or X-ray.   An electronic component, at least a part of which is formed of the positive resist composition according to claim 1 or a cured product thereof.