JP2017125182A - Polymer for forming resist underlay film and production method thereof, composition for forming resist underlay film, resist underlay film, and method for manufacturing patterned substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a polymer for forming a resist underlay film which allows use of PGMEA or the like as a solvent and enables formation of a resist underlay film excellent in edge rinsing property, solvent resistance, etching resistance, heat resistance and filling property; and a composition for forming a resist underlay film.SOLUTION: The polymer for forming a resist underlay film has a first repeating unit represented by formula (1) below. In formula (1), Ar, Arand Areach independently represent a substituted or unsubstituted arenediyl group having 6 to 30 carbon atoms; Rrepresents a substituted or unsubstituted divalent hydrocarbon group having 1 to 30 carbon atoms; n represents 0 or 1; Rrepresents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms; Rrepresents a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms; and Rrepresents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 30 carbon atoms.SELECTED DRAWING: None

Description

  The present invention relates to a polymer for forming a resist underlayer film and a method for producing the same, a composition for forming a resist underlayer film, a resist underlayer film, and a method for producing a patterned substrate.

  In the manufacture of semiconductor devices, a multilayer resist process is used to obtain a high degree of integration. In this process, first, a resist underlayer film forming composition is applied to one side of a substrate to form a resist underlayer film, and a resist composition is applied to the opposite side of the resist underlayer film from the substrate. A resist film is formed. Then, the resist film is exposed through a mask pattern or the like and developed with an appropriate developer to form a resist pattern. Then, the resist underlayer film is dry-etched using this resist pattern as a mask, and the substrate is further etched using the obtained resist underlayer film pattern as a mask, thereby forming a desired pattern on the substrate and obtaining a patterned substrate. Can do. The resist underlayer film used in such a multilayer resist process is required to have general characteristics such as optical characteristics such as refractive index and extinction coefficient, solvent resistance, and etching resistance.

  In recent years, pattern miniaturization has further progressed in order to increase the degree of integration, and even in the above-described multilayer resist process, the resist underlayer film and the composition for forming the same have the following various characteristics. Is required. In response to this requirement, various studies have been conducted on the structure of compounds and the like contained in the composition and the functional groups contained therein (see JP 2004-177668 A).

  In the conventional resist underlayer film forming composition, the compound contained is generally poor in solubility in a solvent such as propylene glycol monomethyl ether acetate (PGMEA) due to its structure and the like. For this reason, there is an inconvenience that it is difficult to form a uniform resist underlayer film as a result of poor applicability to the substrate.

  Recently, in the multilayer resist process, a method of forming a hard mask as an intermediate layer on the resist underlayer film has been studied. Specifically, in this method, an inorganic hard mask is formed on the resist underlayer film by the CVD method. In particular, in the case of a nitride-based inorganic hard mask, the temperature is at least 300 ° C., usually 400 ° C. or higher. High heat resistance is required for the lower layer film. However, the resist underlayer film formed from the above conventional resist underlayer film forming composition has insufficient heat resistance, the resist underlayer film component sublimates, and the sublimated component is reattached to the substrate to form a semiconductor device. There is an inconvenience that the manufacturing yield is reduced.

JP 2004-177668 A

  Furthermore, recently, there is an increasing number of cases where a pattern is formed on a substrate having a plurality of types of trenches, particularly trenches having different aspect ratios, and these trenches are sufficiently embedded in the resist underlayer film to be formed. It is required to be a thing. However, in the conventional composition for forming a resist underlayer film, such embedding property is insufficient, and the resist underlayer film and the hard mask to be formed have voids and become non-uniform. Therefore, as a result, there is a disadvantage that the lithography characteristics of the obtained resist pattern are deteriorated.

  The present invention has been made based on the circumstances as described above, and its purpose is to use PGMEA or the like as a solvent, and a resist excellent in edge rinse, solvent resistance, etching resistance, heat resistance and embedding property. The object is to provide a resist underlayer film forming polymer capable of forming an underlayer film, a resist underlayer film forming polymer manufacturing method, a resist underlayer film forming composition, a resist underlayer film, and a patterned substrate manufacturing method.

（式（１）中、Ａｒ^１、Ａｒ^２及びＡｒ^３は、それぞれ独立して、置換又は非置換の炭素数６〜３０のアレーンジイル基である。Ｒ^１は、置換又は非置換の炭素数１〜３０の２価の炭化水素基である。ｎは、０又は１である。Ｒ^２は、水素原子、置換若しくは非置換の炭素数１〜１０のアルキル基又は置換若しくは非置換の炭素数６〜３０のアリール基である。Ｒ^３は、置換又は非置換の炭素数６〜３０の１価の芳香族炭化水素基である。Ｒ^４は、水素原子、置換若しくは非置換の炭素数１〜１０のアルキル基又は置換若しくは非置換の炭素数６〜３０の２価の芳香族炭化水素基である。） The invention made in order to solve the above problems is a resist underlayer film forming polymer having a first repeating unit represented by the following formula (1) (hereinafter also referred to as “repeating unit (I)”) Also referred to as “[A] polymer”).

(In the formula (1), Ar ¹ , Ar ² and Ar ³ are each independently a substituted or unsubstituted arenediyl group having 6 to 30 carbon atoms. R ¹ is a substituted or unsubstituted carbon number 1 A divalent hydrocarbon group of ˜30, n is 0 or 1. R ² is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted carbon number of 6; R ³ is a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms, and R ⁴ is a hydrogen atom, a substituted or unsubstituted carbon atom having 1 to 3 carbon atoms. 10 alkyl groups or substituted or unsubstituted divalent aromatic hydrocarbon groups having 6 to 30 carbon atoms.)

  Another invention made in order to solve the said subject contains the said polymer for resist underlayer film formation ([A] polymer), and an organic solvent (henceforth "[B] organic solvent"). A composition for forming a resist underlayer film.

  Yet another invention made to solve the above-described problems is a resist underlayer film formed from the resist underlayer film forming composition.

  Still another invention made in order to solve the above-described problems includes a step of forming a resist underlayer film on one surface side of the substrate, and a step of forming a resist pattern on the surface side of the resist underlayer film opposite to the substrate And a step of forming a pattern on the substrate by etching a plurality of times using the resist pattern as a mask, wherein the resist underlayer film is formed from the resist underlayer film forming composition. is there.

（式（３）中、Ａｒ^１’及びＡｒ^３’は、それぞれ独立して、置換又は非置換の炭素数６〜３０のアリール基である。Ａｒ^２は、置換又は非置換の炭素数６〜３０のアレーンジイル基である。Ｒ^１は、炭素数１〜３０の２価の炭化水素基である。ｎは、０又は１である。Ｒ^２は、水素原子、置換若しくは非置換の炭素数１〜１０のアルキル基又は置換若しくは非置換の炭素数６〜３０のアリール基である。Ｒ^３は、置換又は非置換の炭素数６〜３０の１価の芳香族炭化水素基である。
式（４）中、Ｒ^４は、水素原子又は置換若しくは非置換の炭素数１〜３０の１価の炭化水素基である。） Still another invention made in order to solve the above problems is a resist underlayer film forming polymer comprising a step of reacting a compound represented by the following formula (3) and a compound represented by the following formula (4): It is a manufacturing method.

(In Formula (3), Ar ^{1 ′} and Ar ^{3 ′} are each independently a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. Ar ² is a substituted or unsubstituted carbon group having 6 to 6 carbon atoms. 30 is an arenediyl group, R ¹ is a divalent hydrocarbon group having 1 to 30 carbon atoms, n is 0 or 1. R ² is a hydrogen atom, substituted or unsubstituted carbon number 1 Or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and R ³ is a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms.
In formula (4), R ⁴ is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 30 carbon atoms. )

  According to the composition for forming a resist underlayer film of the present invention, PGMEA or the like can be used as a solvent, and a resist underlayer film excellent in edge rinse, solvent resistance, etching resistance, heat resistance, and embedding property can be formed. . The resist underlayer film of the present invention is excellent in edge rinse, solvent resistance, etching resistance, heat resistance and embedding property. According to the method for producing a patterned substrate of the present invention, a patterned substrate having an excellent pattern shape can be obtained by using the excellent resist underlayer film formed as described above. Therefore, these can be suitably used for manufacturing semiconductor devices and the like that are expected to be further miniaturized in the future.

<[A] polymer>
[A] The polymer is a polymer having the repeating unit (I). [A] In addition to the repeating unit (I), the polymer contains other repeating units such as a second repeating unit represented by the formula (2) described later (hereinafter also referred to as “repeating unit (II)”). You may have. [A] Formula (1) showing a repeating unit of a polymer is such that [A] polymer is Ar ^{1 ′} -(R ¹ -Ar ² ) _n -CR ² R ³ -Ar ^{3 ′} (Ar ^{1 ′} and Ar ^{3 ′} will be described later) and a compound represented by R ⁴ CHO and the like. For example, those in which R ² and R ³ in formula (1) are bonded to other repeating units are also included.

[Repeating unit (I)]
The repeating unit (I) is represented by the following formula (1).

In the above formula (1), Ar ¹ , Ar ² and Ar ³ are each independently a substituted or unsubstituted arenediyl group having 6 to 30 carbon atoms. R ¹ is a substituted or unsubstituted divalent hydrocarbon group having 1 to 30 carbon atoms. n is 0 or 1. R ² is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. R ³ is a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. R ⁴ is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 30 carbon atoms.

Ar ^1, as the arenediyl group having 6 to 30 carbon atoms represented by Ar ² and Ar ^3, such as benzene, naphthalene, anthracene, phenanthrene, pyrene, chrysene, tetracene, perylene, arenes having 6 to 30 carbon atoms such as pentacene A group obtained by removing two hydrogen atoms from

  Examples of the substituent for the arenediyl group include a monovalent group including an alkyl group, a hydroxy group, an alkoxy group, and a cyano group, a monovalent group including a carbon-carbon triple bond, and a monovalent group including a carbon-carbon double bond. And halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom.

As Ar ¹ , Ar ² and Ar ³ , more specifically, for example, groups represented by the following formulas (5), (6), (7) and (8) (hereinafter, “group (5) , “Group (6)”, “group (7)” and “group (8)”).

In the above formulas (5) to (8), R ^{6 to} R ⁹ are each an alkyl group, a hydroxy group, an alkoxy group, a monovalent group containing a cyano group, a monovalent group containing a carbon-carbon triple bond, carbon- A monovalent group containing a carbon double bond or a halogen atom. * Indicates a bond.
In said formula (5), c1 is an integer of 0-4. When c1 is 2 or more, the plurality of R ⁶ may be the same or different. r1 is 2.
In said formula (6), c2 is an integer of 0-6. When c2 is 2 or more, the plurality of R ⁷ may be the same or different. r2 is 2.
In said formula (7), c3 is an integer of 0-8. When c3 is 2 or more, the plurality of R ⁸ may be the same or different. r3 is 2.
In said formula (8), c4 is an integer of 0-8. When c4 is 2 or more, the plurality of R ⁹ may be the same or different. r4 is 2.

Examples of the alkyl group represented by R ^{6 to} R ⁹ include an alkyl group having 1 to 20 carbon atoms, and include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, A decyl group etc. are mentioned.

Examples of the alkoxy group represented by R ^{6 to} R ⁹ include an alkoxy group having 1 to 20 carbon atoms, and include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, and an octyl group. An oxy group, a decyloxy group, etc. are mentioned.

Examples of the monovalent group containing a cyano group represented by R ^{6 to} R ⁹ include a monovalent group containing a cyano group having 1 to 20 carbon atoms, such as a cyanomethyl group, a cyanoethyl group, and cyanopropyl. Group, cyanobutyl group, cyanopentyl group, cyanohexyl group, cyanooctyl group, cyanodecyl group, etc .: cyanomethyloxy group, cyanoethyloxy group, cyanopropyloxy group, cyanobutyloxy group, cyanopentyloxy group, cyano And cyanoalkyloxy groups such as a hexyloxy group, a cyanooctyloxy group, and a cyanodecyloxy group.

Examples of the monovalent group containing a carbon-carbon triple bond represented by R ^{6 to} R ⁹ include a monovalent group containing a carbon-carbon triple bond having 2 to 20 carbon atoms, such as an ethynyl group. , Alkynyl groups such as propargyl group, 3-butynyl group, 2-butynyl group, 4-pentynyl group, 5-hexynyl group; ethynyloxy group, propargyloxy group, 3-butynyloxy group, 2-butynyloxy group, 4-pentynyl Examples thereof include alkynyloxy groups such as oxy group and 5-hexynyloxy group.

Examples of the monovalent group containing a carbon-carbon double bond represented by R ^{6 to} R ⁹ include a monovalent group containing a carbon-carbon double bond having 2 to 20 carbon atoms. An alkenyl group such as ethenyl group, 2-propenyl group, 3-butenyl group, 2-butenyl group, 4-pentenyl group, 5-hexenyl group; ethenyloxy group, 2-propenyloxy group, 3-butenyloxy group, 2-butenyloxy group , Alkenyloxy groups such as 4-pentenyloxy group and 5-hexenyloxy group; groups containing an aromatic ring and a double bond such as phenylethenyl group and phenylpropenyl group.

Examples of the halogen atom represented by R ^{6 to} R ⁹ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

R ^{6 to} R ⁹ are preferably a monovalent group containing a carbon-carbon triple bond and a monovalent group containing a cyano group. As the monovalent group containing a carbon-carbon triple bond, an alkynyloxy group is preferable, and a propargyloxy group is particularly preferable. As the monovalent group containing a cyano group, a cyanoalkyloxy group is preferable, and a cyanomethyloxy group is particularly preferable. [A] The polymer has a group containing a carbon-carbon triple bond and / or a monovalent group containing a cyano group, so that the crosslinkability is improved. As a result, the solvent resistance, etching resistance and heat resistance of the resist underlayer film are improved. In addition, the embedding property can be improved.

  As said c1, 1 is preferable. As said c2, 1 is preferable. As said c3, 0 and 1 are preferable and 0 is more preferable. The c4 is preferably 0 or 1, more preferably 0.

Examples of the divalent hydrocarbon group having 1 to 30 carbon atoms represented by R ¹ in the above formula (1) include a methanediyl group, an ethanediyl group, a propanediyl group, a butanediyl group, a pentanediyl group, a hexanediyl group, and an octanediyl group. , Divalent chain hydrocarbon groups such as alkanediyl groups such as decanediyl group, tetradecanediyl group, octadecanediyl group and icosanediyl group. Among these, a methanediyl group, an ethanediyl group, a propanediyl group and a butanediyl group are preferable, and a methanediyl group and an ethanediyl group are more preferable.

Examples of the substituent for the divalent hydrocarbon group include a hydroxy group, a halogen atom, and a group represented by R ² in the above formula (1).

Examples of the alkyl group having 1 to 10 carbon atoms represented by R ² in the above formula (1) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, and a decyl group. It is done.

Examples of the aryl group having 6 to 30 carbon atoms represented by R ² in the above formula (1) include a phenyl group, a tolyl group, a xylyl group, and a naphthyl group.

  Examples of the substituent for the alkyl group and aryl group include a fluorine atom, a chlorine atom, a bromine atom, a halogen atom such as an iodine atom, and a hydroxy group.

Examples of the alkyl group having 1 to 10 carbon atoms substituted by the fluorine atom represented by R ² in the above formula (1) include fluorine such as a fluoromethyl group, a trifluoromethyl group, a perfluoroethyl group, and a perfluoropropyl group. Alkyl group and the like.

Examples of the monovalent aromatic hydrocarbon group represented by R ³ in the above formula (1) include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a pyrenyl group, a chrysenyl group, a tetracenyl group, a perylenyl group, and a pentacenyl group. Etc.

  Examples of the substituent for the monovalent aromatic hydrocarbon group include a monovalent group including an alkyl group, a hydroxy group and a cyanoalkyl group, a monovalent group including a carbon-carbon triple bond, and a carbon-carbon double bond. A monovalent group containing a halogen atom, and the like.

More specifically, examples of R ³ include groups in the case where r1 to r4 are set to 1 in the above formulas (5) to (8).

Examples of the monovalent hydrocarbon group having 1 to 30 carbon atoms represented by R ⁴ in the formula (1) include a chain hydrocarbon group such as an alkyl group such as a methyl group, an ethyl group, and a propyl group;
An alicyclic hydrocarbon group such as a cycloalkyl group such as a cyclopentyl group, a cyclohexyl group or a norbornyl group;
An aromatic hydrocarbon group such as an aryl group such as a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a pyrenyl group, and a tetracenyl group.

  Examples of the substituent of the monovalent hydrocarbon group include an alkyl group, a monovalent group containing a cyanoalkyl group, a monovalent group containing a carbon-carbon triple bond, and a monovalent group containing a carbon-carbon double bond. Group, hydroxy group, halogen atom and the like.

  Examples of the repeating unit (I) include a repeating unit represented by the following formula (1-1) (hereinafter, also referred to as “repeat unit (I-1)”), and a formula (1-2) below. Repeating units (hereinafter also referred to as “repeating units (I-2)”) and the like.

In the formulas (1-1) and (1-2), R ⁴ has the same meaning as the formula (1).
In the above formula (1-1), R ^X1 and R ^Y1 are each independently a monovalent group containing an alkyl group, a hydroxy group, an alkoxy group or a cyano group, or a monovalent group containing a carbon-carbon triple bond. , A monovalent group containing a carbon-carbon double bond, a halogen atom, or the like. i1 and j1 are each independently an integer of 0 to 4. When i1 is 2 or more, the plurality of R ^X1 may be the same or different. When j1 is 2 or more, the plurality of R ^Y1 may be the same or different. R ^V1 has the same ^{meaning as} R ² in the above formula (1). R ^W1 has the same ^{meaning as} R ³ in the above formula (1).
In the above formula (1-2), R ^X2 , R ^Y2 and R ^Z2 each independently represent a monovalent group including an alkyl group, a hydroxy group, an alkoxy group and a cyano group, and a carbon-carbon triple bond 1 A monovalent group containing a carbon-carbon double bond, a halogen atom, or the like. i2, j2 and k2 are each independently an integer of 0 to 4. When i2 is 2 or more, the plurality of R ^X2 may be the same or different. When j2 is 2 or more, the plurality of R ^Y2 may be the same or different. When k2 is 2 or more, the plurality of R ^Z2 may be the same or different. R ^V2 and R ^W2 are each independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. R ^V3 has the same ^{meaning as} R ² in the above formula (1). R ^W3 are the same as ^{R 3} in the formula (1).

Monovalent group including alkyl group, hydroxy group, alkoxy group, cyano group, monovalent group including carbon-carbon triple bond, carbon represented by R ^X1 , R ^X2 , R ^Y1 , R ^Y2 and R ^Z2 Examples of the monovalent group containing a carbon double bond and a halogen atom include the same groups as those exemplified as the respective groups represented by R ^{6 to} R ⁹ . Among these, a monovalent group containing a hydroxy group, a cyano group and a monovalent group containing a carbon-carbon triple bond are preferred, and a hydroxy group, a cyanoalkyl group and a propargyloxy group are more preferred.

  As said i1, i2, j1, and k2, 0-2 are preferable, 0 and 1 are more preferable, and 1 is further more preferable. As said j2, 0-2 are preferable, 0 and 1 are more preferable, and 0 is further more preferable.

As R ^V1 , R ^V2 , R ^V3 , R ^W1 , R ^W2 and R ^W3 , an alkyl group and a substituted and unsubstituted aryl group are preferable, and an alkyl group, an aryl group, a hydroxy-substituted aryl group, and a carbon-carbon triple bond are represented. More preferably an aryl group substituted with a monovalent group, more preferably an alkyl group, an aryl group, a hydroxy-substituted aryl group and a propargyloxy group-substituted aryl group, a methyl group, a phenyl group, a hydroxyphenyl group and a propargyloxyphenyl group. Is particularly preferred.

R ⁴ is preferably a hydrogen atom, a methyl group, an ethyl group, a propyl group, a cyclopentyl group, a cyclohexyl group, a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a pyrenyl group and a tetracenyl group, and a hydrogen atom, a methyl group, a phenyl group A group, a naphthyl group, an anthryl group, a phenanthryl group and a pyrenyl group are more preferable.

  [A] The polymer may have one or more repeating units (I).

  As a minimum of the content rate of repeating unit (I), 10 mol% is preferable with respect to all the repeating units which comprise a [A] polymer, 20 mol% is more preferable, 30 mol% is further more preferable, 40 mol% % Is particularly preferred. As an upper limit of the said content rate, 100 mol% is preferable, 85 mol% is more preferable, and 80 mol% is further more preferable. By setting the content ratio of the repeating unit (I) within the above range, the heat resistance and embedding property of the resist underlayer film can be further improved.

[Repeating unit (II)]
The repeating unit (II) is a repeating unit represented by the following formula (2).

In said formula (2), Ar < ⁴ > is a C6-C30 bivalent aromatic hydrocarbon group substituted or unsubstituted. R ⁵ is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 30 carbon atoms.

Examples of the substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms represented by Ar ⁴ include the substituted or unsubstituted monovalent aromatic group having 6 to 30 carbon atoms exemplified as R ³ above. And a group obtained by removing one hydrogen atom from an aromatic hydrocarbon group. Examples of the substituted or unsubstituted monovalent hydrocarbon group having 1 to 30 carbon atoms represented by R ⁵ include the same groups as those exemplified as the same group of R ⁴ in the above formula (1). .

More specifically, examples of the divalent aromatic hydrocarbon group having 6 to 30 carbon atoms represented by Ar ⁴ include, for example, a benzenediyl group, a naphthalenediyl group, an anthracenediyl group, a phenanthrenediyl group, a pyrenediyl group, Examples include chrysenediyl group, tetracenediyl group, perylenediyl group, pentacenediyl group, and fluorenediyl group. More specifically, for example, the groups represented by the above formulas (5) to (8), the group represented by the following formula (9) (hereinafter, also referred to as “group (9)”), and the formula (10) And a group represented (hereinafter, also referred to as “group (10)”).

In the above formula (9), R ^{10 to} R ¹³ are each independently a monovalent group containing an alkyl group, a hydroxy group, an alkoxy group or a cyano group, a monovalent group containing carbon-carbon triple bond, or carbon. -A monovalent group containing a carbon double bond. m1 and m2 are each independently an integer of 0-2. a1 and a2 are each independently an integer of 0 to 9. n1 and n2 are each independently an integer of 0-2. a3 and a4 are each independently an integer of 0 to 8. When there are a plurality of R ^{10 to} R ¹⁴ , the plurality of R ¹⁰ may be the same or different, the plurality of R ¹¹ may be the same or different, and the plurality of R ¹² may be the same or different. A plurality of R ¹³ may be the same or different. p1 and p2 are each independently an integer of 0-2. p3 and p4 are each independently an integer of 0 to 2. However, p1 + p2 + p3 + p4 is 2. a1 + p1 and a2 + p2 are each 9 or less. a3 + p3 and a4 + p4 are each 8 or less. * Indicates a binding site with a moiety other than the group (9) in the [A] polymer.

In the above formula (10), R ^{14 to} R ¹⁷ are each independently an alkyl group, a hydroxy group, an alkoxy group, a monovalent group containing a cyano group, a monovalent group containing a carbon-carbon triple bond, or carbon. -A monovalent group containing a carbon double bond. b1 and b3 are each independently an integer of 0-2. b2 and b4 are each independently an integer of 0 to 3. When there are a plurality of R ^{14 to} R ¹⁷ , the plurality of R ¹⁴ may be the same or different, the plurality of R ¹⁵ may be the same or different, and the plurality of R ¹⁶ may be the same or different. A plurality of R ¹⁷ may be the same or different. q1 and q3 are each independently an integer of 0 to 2. q2 and q4 are each independently an integer of 0 to 2. However, q1 + q2 + q3 + q4 is 2. b1 + q1 and b3 + q3 are each 2 or less. b2 + q2 and b4 + q4 are each 3 or less. * Indicates a binding site with a moiety other than the group (10) in the [A] polymer.

As an alkyl group, an alkoxy group, a monovalent group containing a cyano group, a monovalent group containing a carbon-carbon triple bond and a monovalent group containing a carbon-carbon double bond represented by R ^{10 to} R ^17. Examples thereof include those similar to the same groups exemplified as R ^{6 to} R ⁹ above.

R ^{10 to} R ¹⁷ are preferably a monovalent group containing a carbon-carbon triple bond and a monovalent group containing a cyano group. As the monovalent group containing a carbon-carbon triple bond, an alkynyloxy group is preferable, and a propargyloxy group is particularly preferable. As the monovalent group containing a cyano group, a cyanoalkyloxy group is preferable, and a cyanomethyloxy group is particularly preferable. [A] The polymer has a group containing a carbon-carbon triple bond and / or a monovalent group containing a cyano group, so that the crosslinkability is improved. As a result, the solvent resistance, etching resistance and heat resistance of the resist underlayer film are improved. In addition, the embedding property can be improved.

  As m1 and m2 in the above formula (9), 0 and 1 are preferable. As a1 and a2, the integer of 0-2 is preferable, 0 and 1 are more preferable, and 1 is further more preferable. As a3 and a4, the integer of 0-2 is preferable, 0 and 1 are more preferable, and 0 is more preferable. As p1 and p2, 0 and 1 are preferable and 1 is more preferable. As p3 and p4, 0 and 1 are preferable and 0 is more preferable.

  As b1 and b3 in the above formula (10), 0 and 1 are preferable, and 0 is more preferable. As b2 and b4, an integer of 0 to 2 is preferable, 0 and 1 are more preferable, and 0 is more preferable. As q1 and q4, 0 and 1 are preferable and 1 is more preferable. As q2 and q3, 0 and 1 are preferable, and 0 is more preferable.

  Examples of the group (9) include groups represented by the following formulas (9-1) to (9-5) (hereinafter also referred to as “groups (9-1) to (9-5)”). It is done. Examples of the group (10) include groups represented by the following formulas (10-1) to (10-4) (hereinafter also referred to as “groups (10-1) to (10-4)”). It is done.

In the above formulas (9-1) to (9-5), R ^A each independently represents an alkyl group, a hydroxy group, an alkoxy group, a monovalent group containing a cyano group, or 1 containing a carbon-carbon triple bond. A monovalent group containing a valent group or a carbon-carbon double bond. p1-p4 is synonymous with the said Formula (9). * Indicates a binding site with a moiety other than the groups (9-1) to (9-5) in the [A] polymer.

In the above formulas (10-1) to (10-4), R ^A each independently represents an alkyl group, a hydroxy group, an alkoxy group, a monovalent group containing a cyano group, or a carbon-carbon triple bond. A monovalent group containing a valent group or a carbon-carbon double bond. q1-q4 is synonymous with the said Formula (10). * Indicates a binding site with a moiety other than the groups (10-1) to (10-4) in the [A] polymer.

  As said group (9), group (9-1) and (9-2) are preferable. As the group (10), groups (10-1) and (10-2) are preferred.

  [A] The polymer may have one or more repeating units (II). The repeating unit (II) preferably has at least one of the groups (5) to (10). In the case of having at least one of the groups (5) to (8), the [A] polymer has higher solubility in a solvent, and as a result, the edge rinse property and embedding property of the resist underlayer film are more improved. improves. Moreover, when it has group (9) or group (10), the etching resistance and heat resistance of the [A] polymer are further improved.

  When the repeating unit (II) has at least one of the group (5) to the group (8), the lower limit of the total content of the repeating units including the group (5) to the group (8) is [A ] 10 mol% is preferable with respect to all repeating units constituting the polymer, 20 mol% is more preferable, and 30 mol% is more preferable. As an upper limit of the said content rate, 90 mol% is preferable, 80 mol% is more preferable, and 70 mol% is further more preferable. By making the sum total of the content rate of the repeating unit containing group (5)-group (8) into the said range, the solubility to the solvent of a [A] polymer can be improved more, As a result, resist underlayer film The edge rinse property and embedding property can be further improved.

  When the repeating unit (II) has the group (9) or the group (10), the lower limit of the total content of the repeating units containing the group (9) or the group (10) constitutes the [A] polymer. 10 mol% is preferable with respect to all repeating units, 20 mol% is more preferable, and 30 mol% is further more preferable. As an upper limit of the said content rate, 90 mol% is preferable, 80 mol% is more preferable, and 70 mol% is further more preferable. By making the content rate of the repeating unit containing group (9) or group (10) into the said range, the content rate of the polycyclic structure in [A] polymer can be raised, As a result, resist underlayer film Heat resistance and embedding can be achieved at a higher level.

  As a minimum of the content rate of repeating unit (II), 10 mol% is preferable with respect to all the repeating units which comprise a [A] polymer, 20 mol% is more preferable, 30 mol% is further more preferable, 40 mol% % Is particularly preferred. As an upper limit of the said content rate, 90 mol% is preferable, 80 mol% is more preferable, and 70 mol% is further more preferable. By making the content rate of repeating unit (II) into the said range, the heat resistance and embedding property of a resist underlayer film can further be improved.

  [A] When the polymer has other repeating units other than the repeating unit (I) and the repeating unit (II), the lower limit of the content ratio of the other repeating units is [A] all repeating units constituting the polymer. 1 mol% is preferable, 5 mol% is more preferable, and 10 mol% is further more preferable. As an upper limit of the said content rate, 60 mol% is preferable, 50 mol% is more preferable, 40 mol% is further more preferable, 30 mol% is especially preferable. By making the content rate of another repeating unit into the said range, the solvent tolerance of a resist underlayer film, etching tolerance, heat resistance, and embedding property can further be improved.

  [A] Examples of the polymer include polymers represented by the following formulas (i-1) to (i-29) (hereinafter also referred to as “polymers (i1) to (i29)”).

  Among these, as the [A] polymer, the polymers (i1) to (i29) are preferable, and the polymers (i15) to (i29) are more preferable.

  [A] The lower limit of the content of the polymer is preferably 70% by mass, more preferably 80% by mass, based on the total solid content (components other than the solvent) in the resist underlayer film forming composition, 85 More preferred is mass%. The solid content concentration was determined by baking the resist underlayer film forming composition 0.5 g for 30 minutes at 250 ° C., measuring the solid content mass with respect to the resist underlayer film forming composition 0.5 g, and forming the resist underlayer film formation. It is calculated | required by calculating the solid content concentration (mass%) of the composition for medical use.

<[A] Production method of polymer>
[A] The polymer can be synthesized by a known method. [A] When the polymer is a polymer obtained by reacting a compound represented by the following formula (3) with a compound (aldehyde) represented by the following formula (4), first, for example, the following formula A polymer obtained by reacting a compound represented by (3) and a precursor compound such as a compound represented by the following formula (4) in a solvent such as propylene glycol monomethyl ether acetate in the presence of an acid. Can do. The polymer further comprises the obtained polymer and a compound forming a monovalent group containing a carbon-carbon triple bond such as propargyl bromide in the presence of a base such as N, N-dimethylacetamide. [A] polymer containing a carbon-carbon triple bond etc. is compoundable by making it react in a solvent. One or two or more of the precursor compounds can be used, and the use ratio can be appropriately selected depending on the desired performance of the resist underlayer film. Moreover, the use ratio of the compound represented by the following formula (3) and the aldehyde in the precursor compound can be appropriately selected depending on the desired performance of the resist underlayer film.

In the above formula (3), Ar ^{1 ′} and Ar ^{3 ′} are each independently a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. Ar ² is a substituted or unsubstituted arenediyl group having 6 to 30 carbon atoms. R ¹ is a divalent hydrocarbon group having 1 to 30 carbon atoms. n is 0 or 1. R ² is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. R ³ is a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms.
In the formula (4), R ⁴ is a monovalent hydrocarbon group having a hydrogen atom or a substituted or unsubstituted C1-30.

  Specific examples of the compound represented by the above formula (4) include one aldehyde group such as formaldehyde (paraformaldehyde), acetaldehyde (paraaldehyde), propionaldehyde, butyraldehyde, benzaldehyde, naphthaldehyde, formylpyrene and the like. Compound; Examples include compounds containing two or more aldehyde groups such as 1,4-phenylenedialdehyde and 4,4′-biphenylenedialdehyde. Among these, the compound containing one aldehyde group from the viewpoint that the solvent resistance, etching resistance, heat resistance and embedding property of the resist underlayer film are further improved by the [A] polymer having a more appropriate crosslinked structure. Are preferable, formaldehyde and formylpyrene are more preferable, and formaldehyde is more preferable.

  Examples of the acid include sulfonic acids such as p-toluenesulfonic acid and benzenesulfonic acid; inorganic acids such as sulfuric acid, hydrochloric acid and nitric acid. Among these, sulfonic acid is preferable, and p-toluenesulfonic acid is more preferable.

  As a minimum of the usage-amount of an acid, 1 mol is preferable with respect to 1 mol of aldehydes, and 5 mol is more preferable. The upper limit of the amount used is preferably 20 mol, and more preferably 10 mol.

  As a minimum of reaction temperature of a synthetic reaction of a polymer which has phenolic hydroxyl group, 60 ° C is preferred and 80 ° C is more preferred. As an upper limit of the said reaction temperature, 150 degreeC is preferable and 120 degreeC is more preferable. As a minimum of reaction time of the above-mentioned reaction, 1 hour is preferred and 4 hours is more preferred. The upper limit of the reaction time is preferably 24 hours, and more preferably 12 hours.

  Examples of the base include alkali metal carbonates such as potassium carbonate and sodium carbonate; alkali metal hydrogen carbonates such as lithium hydrogen carbonate, sodium hydrogen carbonate and potassium hydrogen carbonate; alkali metal hydroxides such as potassium hydroxide and sodium hydroxide An alkali metal hydride such as lithium hydride, sodium hydride, potassium hydride and the like; Of these, alkali metal carbonates are preferred, and potassium carbonate is more preferred.

  As a minimum of the usage-amount of a base, 0.1 mol is preferable with respect to 1 mol of compounds which form the monovalent group containing the said carbon-carbon triple bond, 0.5 mol is more preferable, 0.8 mol Is more preferable. The upper limit of the amount used is preferably 3 mol, more preferably 2 mol, and even more preferably 1.5 mol.

  The lower limit of the reaction temperature of the reaction in which the above polymer is reacted with a compound that forms a monovalent group containing a carbon-carbon triple bond to obtain the [A] polymer containing a carbon-carbon triple bond or the like is 50 ° C is preferred, and 60 ° C is more preferred. As an upper limit of the said reaction temperature, 130 degreeC is preferable and 100 degreeC is more preferable. As a minimum of reaction time of the above-mentioned reaction, 1 hour is preferred and 4 hours is more preferred. The upper limit of the reaction time is preferably 24 hours, and more preferably 12 hours.

  The synthesized [A] polymer can be purified from the reaction solution by liquid separation operation, reprecipitation, recrystallization, distillation or the like. [A] polymers other than the above can also be synthesized in the same manner as described above.

  [A] The lower limit of the weight average molecular weight (Mw) of the polymer is preferably 1,000, and more preferably 2,000. The upper limit of Mw is preferably 15,000, more preferably 10,000, even more preferably 8,000, and particularly preferably 6,000. A weight average molecular weight (Mw) is a polystyrene equivalent weight average molecular weight (Mw) by gel permeation chromatography (GPC).

  [A] By setting the molecular weight of the polymer within the above range, the edge rinse property, solvent resistance, etching resistance, heat resistance and embedding property of the resist underlayer film can be further improved.

  [A] The upper limit of the ratio (Mw / Mn ratio) of the polymer Mw to the number average molecular weight (Mn) is preferably 5, more preferably 3, more preferably 2, and particularly preferably 1.8. The lower limit of the ratio is usually 1 and preferably 1.2. [A] By setting the Mw / Mn ratio of the polymer in the above range, the embedding property of the resist underlayer film can be further improved.

<Composition for forming resist underlayer film>
The resist underlayer film forming composition contains a [A] polymer and a [B] organic solvent. The resist underlayer film forming composition may contain a [C] acid generator as a suitable component, and may contain other optional components as long as the effects of the present invention are not impaired. Hereinafter, each component will be described.

<[A] polymer>
[A] The polymer is a resist underlayer film forming polymer having the repeating unit (I) represented by the above formula (1). [A] The polymer has been described above.

<[B] Solvent>
The composition for forming a resist underlayer film contains a [B] solvent. [B] The solvent is not particularly limited as long as it can dissolve or disperse the [A] polymer and optional components contained as necessary.

  [B] Examples of the solvent include alcohol solvents, ketone solvents, ether solvents, ester solvents, nitrogen-containing solvents, and the like. [B] A solvent can be used individually by 1 type or in combination of 2 or more types.

  Examples of the alcohol solvent include methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, tert-butanol, n-pentanol, iso-pentanol, 2-methylbutanol, sec-pentanol, tert-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol , Sec-octanol, n-nonyl alcohol, 2,6-dimethylheptanol-4, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec- Monoalcohol solvents such as ptadecyl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, phenylmethyl carbinol, diacetone alcohol, cresol; ethylene glycol, 1,2- Propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3- Examples thereof include polyhydric alcohol solvents such as hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, and glycerin.

  Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-iso-butyl ketone, methyl-n-pentyl ketone, ethyl-n-butyl ketone, methyl-n- Examples include hexyl ketone, di-iso-butyl ketone, trimethylnonanone, cyclohexanone, methylcyclohexanone, 2,4-pentanedione, acetonylacetone, diacetone alcohol, acetophenone, and fencheon.

  Examples of ether solvents include ethyl ether, iso-propyl ether, n-butyl ether, n-hexyl ether, 2-ethylhexyl ether, ethylene oxide, 1,2-propylene oxide, dioxolane, 4-methyldioxolane, dioxane, dimethyldioxane, 2-methoxyethanol, 2-ethoxyethanol, ethylene glycol diethyl ether, 2-n-butoxyethanol, 2-n-hexoxyethanol, 2-phenoxyethanol, 2- (2-ethylbutoxy) ethanol, ethylene glycol dibutyl ether, diethylene glycol Monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol mono-n-butyl ether, di Tylene glycol di-n-butyl ether, diethylene glycol mono-n-hexyl ether, ethoxytriglycol, tetraethylene glycol di-n-butyl ether, 1-n-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monomethyl Examples include ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, tripropylene glycol monomethyl ether, tetrahydrofuran, and 2-methyltetrahydrofuran. .

  Examples of the ester solvents include diethyl carbonate, methyl acetate, ethyl acetate, γ-butyrolactone, γ-valerolactone, n-propyl acetate, iso-propyl acetate, n-butyl acetate, iso-butyl acetate, sec-butyl acetate, N-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methyl pentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methyl cyclohexyl acetate, n-nonyl acetate, methyl acetoacetate, aceto Ethyl acetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether Ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, glycol diacetate, methoxytriacetate Glycol, ethyl propionate, n-butyl propionate, iso-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-amyl lactate, diethyl malonate, Examples thereof include dimethyl phthalate and diethyl phthalate.

  Examples of the nitrogen-containing solvent include N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpropionamide, N-methyl. Examples include pyrrolidone and the like.

  Among these, ether solvents and ester solvents are preferable, and glycol solvents are more preferable from the viewpoint of excellent film formability.

  Examples of the glycol solvent include propylene glycol monomethyl ether, prolene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate and the like. Among these, propylene glycol monomethyl ether acetate is particularly preferable.

  [B] The lower limit of the content of the glycol solvent in the solvent is preferably 20% by mass, more preferably 60% by mass, still more preferably 90% by mass, and particularly preferably 100% by mass.

<[C] acid generator>
[C] The acid generator is a component that generates an acid by the action of heat or light and promotes crosslinking of the polymer [A]. When the composition for forming a resist underlayer film contains a [C] acid generator, the crosslinking reaction of the [A] polymer is promoted, and the hardness of the formed film can be further increased. [C] An acid generator can be used individually by 1 type or in combination of 2 or more types.

  [C] Examples of the acid generator include onium salt compounds and N-sulfonyloxyimide compounds.

  Examples of the onium salt compounds include sulfonium salts, tetrahydrothiophenium salts, and iodonium salts.

  Examples of the sulfonium salt include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, triphenylsulfonium 2-bicyclo [2.2.1] hept- 2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-cyclohexylphenyldiphenylsulfonium perfluoro- n-octanesulfonate, 4-cyclohexylphenyldiphenylsulfonium 2-bicyclo [2.2.1] hept- -Yl-1,1,2,2-tetrafluoroethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium par Examples include fluoro-n-octane sulfonate, 4-methanesulfonylphenyldiphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethane sulfonate.

  Examples of the tetrahydrothiophenium salt include 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium nona. Fluoro-n-butanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophene Nitro 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium trifluoromethane Sulfonate, 1- (6-n-butoxynaphthalene-2 Yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (6-n-butoxynaphthalene- 2-yl) tetrahydrothiophenium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) ) Tetrahydrothiophenium trifluoromethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydro Thiophenium perfluoro-n-octance Phonates, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, etc. Can be mentioned.

  Examples of the iodonium salt include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hept-2-yl- 1,1,2,2-tetrafluoroethanesulfonate, 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 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetra Le Oro ethanesulfonate.

  Examples of the N-sulfonyloxyimide compound include N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (nonafluoro-n-butanesulfonyloxy). ) Bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (perfluoro-n-octanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2 , 3-dicarboximide, N- (2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonyloxy) bicyclo [2.2.1] hept- 5-ene-2,3-dicarboximide and the like can be mentioned.

  Among these, as the [C] acid generator, an onium salt compound is preferable, an iodonium salt is more preferable, and bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate is more preferable.

When the resist underlayer film forming composition contains a [C] acid generator, the lower limit of the content of the [C] acid generator is 0.1 mass with respect to 100 parts by mass of the [A] polymer. Part is preferred,
1 part by mass is more preferred, and 3 parts by mass is still more preferred. As an upper limit of the said content, 20 mass parts is preferable, 15 mass parts is more preferable, and 10 mass parts is further more preferable. By making content of [C] acid generator into the said range, the crosslinking reaction of [A] polymer can be promoted more effectively.

<Other optional components>
In the resist underlayer film forming composition, other optional components include, for example, a crosslinking agent, a surfactant, an adhesion aid, and the like.

[Crosslinking agent]
The cross-linking agent is a component that forms a cross-linking bond between components such as the [A] polymer in the resist underlayer film forming composition by the action of heat and acid. When the resist underlayer film forming composition contains a crosslinking agent, the hardness of the formed film can be increased. A crosslinking agent can be used individually by 1 type or in combination of 2 or more types.

  Examples of the crosslinking agent include polyfunctional (meth) acrylate compounds, epoxy compounds, hydroxymethyl group-substituted phenol compounds, alkoxyalkyl group-containing phenol compounds, compounds having an alkoxyalkylated amino group, and the following formula (11-P): Examples thereof include random copolymers of acenaphthylene and hydroxymethylacenaphthylene, and compounds represented by the following formulas (11-1) to (11-12).

  Examples of the polyfunctional (meth) acrylate compound include trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and dipentaerythritol penta. (Meth) acrylate, dipentaerythritol hexa (meth) acrylate, glycerin tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, ethylene glycol di (meth) acrylate, 1,3-butanediol Di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) Acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, bis (2-hydroxyethyl) isocyanurate di (meth) acrylate.

  Examples of the epoxy compound include novolac type epoxy resins, bisphenol type epoxy resins, alicyclic epoxy resins, and aliphatic epoxy resins.

  Examples of the hydroxymethyl group-substituted phenol compound include 2-hydroxymethyl-4,6-dimethylphenol, 1,3,5-trihydroxymethylbenzene, 3,5-dihydroxymethyl-4-methoxytoluene [2,6- Bis (hydroxymethyl) -p-cresol] and the like.

  Examples of the alkoxyalkyl group-containing phenol compound include methoxymethyl group-containing phenol compounds and ethoxymethyl group-containing phenol compounds.

  Examples of the compound having an alkoxyalkylated amino group include a plurality of compounds in one molecule such as (poly) methylolated melamine, (poly) methylolated glycoluril, (poly) methylolated benzoguanamine, and (poly) methylolated urea. A nitrogen-containing compound having one active methylol group, wherein at least one hydrogen atom of the hydroxyl group of the methylol group is substituted with an alkyl group such as a methyl group or a butyl group. The compound having an alkoxyalkylated amino group may be a mixture in which a plurality of substituted compounds are mixed, or may include an oligomer component that is partially self-condensed.

  In the above formulas (11-6), (11-8), (11-11) and (11-12), Ac represents an acetyl group.

In addition, the compounds represented by the above formulas (11-1) to (11-12) can be synthesized by referring to the following documents, respectively.
Compound represented by formula (11-1):
Guo, Qun-Shen; Lu, Yong-Na; Liu, Bing; Xiao, Jian; Li, Jin-Shan Journal of Organic Chemistry, 2006, vol. 691, # 6 p. 1282-1287
Compound represented by formula (11-2):
Badar, Y .; et al. Journal of the Chemical Society, 1965, p. 1412-1418
Compound represented by formula (11-3):
Hsieh, Jen-Chieh; Cheng, Chien-Hong Chemical Communications (Cambridge, United Kingdom), 2008, # 26 p. 2992-2994
Compound represented by formula (11-4):
JP-A-5-238990 A compound represented by the formula (11-5):
Bacon, R.A. G. R. Bankhead, R .; Journal of the Chemical Society, 1963, p. 839-845
Compounds represented by formulas (11-6), (11-8), (11-11) and (11-12):
Macromolecules 2010, vol43, p2832-2839
Compounds represented by formulas (11-7), (11-9) and (11-10):
Polymer Journal 2008, vol. 40, no. 7, p645-650, and Journal of Polymer Science: Part A, Polymer Chemistry, Vol 46, p4949-4958.

  Among these crosslinking agents, a methoxymethyl group-containing phenol compound, a compound having an alkoxyalkylated amino group, and a random copolymer of acenaphthylene and hydroxymethylacenaphthylene are preferred, and an alkoxyalkylated amino group is selected. More preferred are compounds having 1,3,4,6-tetra (methoxymethyl) glycoluril.

  When the composition for forming a resist underlayer film contains a crosslinking agent, the lower limit of the content of the crosslinking agent is preferably 0.1 parts by mass with respect to 100 parts by mass of the polymer [A], and 0.5 parts by mass. Part is more preferred, 1 part by weight is more preferred, and 3 parts by weight is particularly preferred. As an upper limit of the said content, 100 mass parts is preferable, 50 mass parts is more preferable, 30 mass parts is further more preferable, 20 mass parts is especially preferable. By making content of a crosslinking agent into the said range, the crosslinking reaction of [A] polymer can be caused more effectively.

[Surfactant]
The composition for forming a resist underlayer film can improve the coating property by containing a surfactant, and as a result, the coating surface uniformity of the formed film is improved and the occurrence of coating spots is suppressed. can do. Surfactant can be used individually by 1 type or in combination of 2 or more types.

  Examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene-n-octylphenyl ether, polyoxyethylene-n-nonylphenyl ether, polyethylene glycol dilaurate, polyethylene Nonionic surfactants such as glycol distearate are listed. Commercially available products include KP341 (Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (above, Kyoeisha Yushi Chemical Co., Ltd.), F-top EF101, EF204, EF303, EF352 (above, Tochem Products), Megafuck F171, F172, F173 (above, DIC), Fluorad FC430 FC431, FC135, FC93 (Sumitomo 3M), Asahi Guard AG710, Surflon S382, SC101, SC102, SC103, SC104, SC105, SC106 (above, Asahi Glass) It is done.

  When the resist underlayer film forming composition contains a surfactant, the lower limit of the surfactant content is preferably 0.01 parts by mass with respect to 100 parts by mass of the [A] polymer. 05 parts by mass is more preferable, and 0.1 part by mass is even more preferable. As an upper limit of the said content, 10 mass parts is preferable, 5 mass parts is more preferable, and 1 mass part is further more preferable. By making content of surfactant into the said range, the applicability | paintability of the said composition for resist underlayer film formation can be improved more.

[Adhesion aid]
The adhesion assistant is a component that improves the adhesion to the substrate. When the composition for forming a resist underlayer film contains an adhesion assistant, the adhesion between the formed resist underlayer film and a substrate or the like as an underlayer can be improved. The adhesion assistant can be used singly or in combination of two or more.

  As the adhesion assistant, for example, a known adhesion assistant can be used.

  When the resist underlayer film forming composition contains an adhesion assistant, the lower limit of the content of the adhesion assistant is preferably 0.01 parts by mass with respect to 100 parts by mass of the [A] polymer. 05 parts by mass is more preferable, and 0.1 part by mass is even more preferable. As an upper limit of the said content, 10 mass parts is preferable, 10 mass parts is more preferable, and 5 mass parts is further more preferable.

<Method for preparing resist underlayer film forming composition>
The resist underlayer film forming composition was preferably obtained by mixing the [A] polymer, the [B] solvent, and, if necessary, the [C] acid generator and other optional components in a predetermined ratio. It can be prepared by filtering the mixture with a membrane filter of about 0.1 μm. The lower limit of the solid content concentration of the resist underlayer film forming composition is preferably 0.1% by mass, more preferably 1% by mass, further preferably 2% by mass, and particularly preferably 4% by mass. The upper limit of the solid content concentration is preferably 50% by mass, more preferably 30% by mass, further preferably 15% by mass, and particularly preferably 8% by mass.

<Method for producing patterned substrate>
The method for producing a patterned substrate of the present invention comprises:
A step of forming a resist underlayer film on one surface side of the substrate (hereinafter also referred to as a “resist underlayer film forming step”),
A process for forming a resist pattern on the side opposite to the substrate of the resist underlayer film (hereinafter also referred to as “resist pattern forming process”), and forming a pattern on the substrate by a plurality of etchings using the resist pattern as a mask (Hereinafter, also referred to as “substrate pattern forming step”). In the method for producing the patterned substrate, the resist underlayer film is formed from the resist underlayer film forming composition described above.

  According to the method for producing the patterned substrate, since the resist underlayer film forming composition described above is used, a resist underlayer film excellent in solvent resistance, etching resistance, heat resistance, and embedding property can be formed. By using an excellent resist underlayer film, a patterned substrate having an excellent pattern shape can be obtained.

[Resist underlayer film forming step]
In this step, a resist underlayer film is formed on one surface side of the substrate with the resist underlayer film forming composition. The formation of the resist underlayer film is usually performed by applying the resist underlayer film forming composition to one surface side of the substrate to form a coating film and heating the coating film.

  Examples of the substrate include a silicon wafer and a wafer coated with aluminum. Moreover, the application | coating method of the said composition for resist underlayer film forming to a board | substrate etc. is not specifically limited, For example, it can implement by appropriate methods, such as spin coating, cast coating, and roll coating.

  The coating film is usually heated in the air. As a minimum of heating temperature, 150 ° C is preferred, 180 ° C is more preferred, and 200 ° C is still more preferred. As an upper limit of heating temperature, 500 degreeC is preferable, 380 degreeC is more preferable, 300 degreeC is further more preferable. When the heating temperature is less than 150 ° C., the oxidative crosslinking does not proceed sufficiently, and there is a possibility that the characteristics necessary for the resist underlayer film are not exhibited. As a minimum of heating time, 15 seconds are preferred, 30 seconds are more preferred, and 45 seconds are still more preferred. The upper limit of the heating time is preferably 1,200 seconds, more preferably 600 seconds, and even more preferably 300 seconds.

  The lower limit of the oxygen concentration during heating is preferably 5% by volume. When the oxygen concentration at the time of heating is low, the oxidative crosslinking of the resist underlayer film does not proceed sufficiently, and there is a possibility that the characteristics necessary for the resist underlayer film cannot be expressed.

  Before heating the coating film at a temperature of 150 ° C. or more and 500 ° C. or less, it may be preheated at a temperature of 60 ° C. or more and 250 ° C. or less. As a minimum of heating time in preliminary heating, 10 seconds are preferred and 30 seconds are more preferred. The upper limit of the heating time is preferably 300 seconds, and more preferably 180 seconds. By performing this preheating, the dehydrogenation reaction can be efficiently advanced by vaporizing the solvent in advance to make the film dense.

  In the resist underlayer film forming method, usually, the coating film is heated to form a resist underlayer film. However, in the case where the resist underlayer film forming composition contains a radiation-sensitive acid generator. Can also form a resist underlayer film by curing the coating film by combining exposure and heating. The radiation used for this exposure includes electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, X-rays and γ rays, and particle beams such as electron beams, molecular beams and ion beams, depending on the type of the radiation-sensitive acid generator. It is selected appropriately.

  As a minimum with the average thickness of the resist underlayer film formed, 0.05 micrometer is preferred, 0.1 micrometer is more preferred, and 0.5 micrometer is still more preferred. The upper limit of the average thickness is preferably 5 μm, more preferably 3 μm, and even more preferably 2 μm.

  After the resist underlayer film forming step, it may further include a step of forming an intermediate layer (intermediate film) on the side of the resist underlayer film opposite to the substrate, if necessary. This intermediate layer is a layer provided with the above functions in order to further supplement the functions of the resist underlayer film and / or the resist film or provide functions that these resist layers do not have in resist pattern formation. . For example, when the antireflection film is formed as an intermediate layer, the antireflection function of the resist underlayer film can be further supplemented.

  This intermediate layer can be formed of an organic compound or an inorganic oxide. Examples of the organic compound include commercially available products such as “DUV-42”, “DUV-44”, “ARC-28”, “ARC-29” (hereinafter, Brewer Science); “AR-3”, “AR -19 "(above, Rohm and Haas). As said inorganic oxide, "NFC SOG01", "NFC SOG04", "NFC SOG080" (above, JSR company) etc. are mentioned as a commercial item, for example. Alternatively, polysiloxane, titanium oxide, alumina oxide, tungsten oxide, or the like formed by a CVD method can be used.

  Although the formation method of an intermediate | middle layer is not specifically limited, For example, the apply | coating method, CVD method, etc. can be used. Among these, a coating method is preferable. When the coating method is used, the intermediate layer can be formed continuously after forming the resist underlayer film. Moreover, although the average thickness of an intermediate | middle layer is suitably selected according to the function calculated | required by an intermediate | middle layer, as a minimum of the average thickness of an intermediate | middle layer, 10 nm is preferable and 20 nm is more preferable. The upper limit of the average thickness is preferably 3,000 nm, and more preferably 300 nm.

[Resist pattern formation process]
In this step, a resist pattern is formed on the opposite side of the resist underlayer film from the substrate. Examples of the method for performing this step include a method using a resist composition.

  In the method using the resist composition, specifically, after applying the resist composition so that the obtained resist film has a predetermined thickness, the resist in the coating film is volatilized by pre-baking. A film is formed.

  Examples of the resist composition include a positive or negative chemically amplified resist composition containing a radiation sensitive acid generator, a positive resist composition comprising an alkali-soluble resin and a quinonediazide-based photosensitizer, and an alkali-soluble resin. And a negative resist composition composed of a crosslinking agent and the like.

  As a minimum of solid content concentration of the above-mentioned resist composition, 0.3 mass% is preferred and 1 mass% is more preferred. As an upper limit of the said solid content concentration, 50 mass% is preferable and 30 mass% is more preferable. In addition, the resist composition is generally filtered through a filter having a pore diameter of about 0.2 μm and provided for forming a resist film. In this step, a commercially available resist composition can be used as it is.

  The method for applying the resist composition is not particularly limited, and examples thereof include a spin coating method. The pre-baking temperature is appropriately adjusted according to the type of resist composition to be used, but the lower limit of the temperature is preferably 30 ° C., more preferably 50 ° C. As an upper limit of the said temperature, 200 degreeC is preferable and 150 degreeC is more preferable. The lower limit of the pre-baking time is preferably 10 seconds, and more preferably 30 seconds. The upper limit of the time is preferably 600 seconds, and more preferably 300 seconds.

Next, the formed resist film is exposed by selective radiation irradiation. As the radiation used for the exposure, electromagnetic waves such as visible rays, ultraviolet rays, far ultraviolet rays, X-rays, γ rays, etc., depending on the type of the radiation-sensitive acid generator used in the resist composition; It is appropriately selected from particle beams such as ion beams. Among these, far ultraviolet rays are preferable, and KrF excimer laser light (248 nm), ArF excimer laser light (193 nm), F ₂ excimer laser light (wavelength 157 nm), Kr ₂ excimer laser light (wavelength 147 nm), ArKr excimer laser light (Wavelength 134 nm) and extreme ultraviolet rays (wavelength 13.5 nm, etc., EUV) are more preferable, and KrF excimer laser light, ArF excimer laser light, and EUV are more preferable.

  After the exposure, post-baking can be performed to improve resolution, pattern profile, developability, and the like. The post-baking temperature is appropriately adjusted according to the type of resist composition to be used, but the lower limit of the temperature is preferably 50 ° C., more preferably 70 ° C. As an upper limit of the said temperature, 200 degreeC is preferable and 150 degreeC is more preferable. The lower limit of the post-bake time is preferably 10 seconds, and more preferably 30 seconds. The upper limit of the time is preferably 600 seconds, and more preferably 300 seconds.

  Next, the exposed resist film is developed with a developer to form a resist pattern. This development may be alkali development or organic solvent development. As the developer, in the case of alkali development, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyl Diethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,5-diazabicyclo [ 4.3.0] -5-nonene and other alkaline aqueous solutions. An appropriate amount of a water-soluble organic solvent such as alcohols such as methanol and ethanol, a surfactant, and the like can be added to these alkaline aqueous solutions. In the case of organic solvent development, examples of the developer include various organic solvents exemplified as the above-mentioned [B] solvent.

  A predetermined resist pattern is formed by washing and drying after development with the developer.

  As a method for performing this resist pattern forming step, a method using a nanoimprint method, a method using a self-organizing composition, and the like can be used in addition to the method using the resist composition described above.

[Substrate pattern formation process]
In this step, a pattern is formed on the substrate by a plurality of etchings using the resist pattern as a mask. When the intermediate layer is not provided, the resist underlayer film and the substrate are sequentially etched, and when the intermediate layer is provided, the intermediate layer, the resist underlayer film and the substrate are sequentially etched. Examples of the etching method include dry etching and wet etching. Among these, dry etching is preferable from the viewpoint of improving the shape of the substrate pattern. For this dry etching, for example, gas plasma such as oxygen plasma is used. After the etching, a substrate having a predetermined pattern is obtained.

<Resist underlayer film>
The resist underlayer film of the present invention is formed from the resist underlayer film forming composition. Since the resist underlayer film is formed from the resist underlayer film forming composition described above, it is excellent in solvent resistance, etching resistance, heat resistance and embedding property.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. The measuring method of various physical property values is shown below.

[Mw and Mn]
[A] Mw and Mn of the polymer were measured using a Tosoh GPC column ("G2000HXL" and "G3000HXL"), flow rate: 1.0 mL / min, elution solvent: tetrahydrofuran, column temperature: 40 Measurement was performed by gel permeation chromatograph (detector: differential refractometer) using monodisperse polystyrene as a standard under the analysis condition of ° C.

[Solid content]
By baking 0.5 g of the resist underlayer film forming composition at 250 ° C. for 30 minutes, the mass of the solid content relative to 0.5 g of the resist underlayer film forming composition was measured, and the solid content of the resist underlayer film forming composition was measured. The concentration (mass%) was calculated.

[Average thickness of film]
The average thickness of the film was measured using a spectroscopic ellipsometer (“M2000D” from JA WOOLLAM).

<[A] Synthesis of polymer>
[Example 1]
In a three-necked flask equipped with a thermometer, condenser and mechanical stirrer, 44.5 ′-(α-methylbenzylidene) bisphenol 34.5 g (118.9 mmol), phenol 2.80 g (29.7 mmol) and under nitrogen 3.49 g of paraformaldehyde was charged. Next, 60 g of propylene glycol monomethyl ether acetate (PGMEA) was added and dissolved, and then 0.220 g (1.28 mmol) of p-toluenesulfonic acid monohydrate was added and stirred at 95 ° C. for 6 hours. Polymerized. Then, the polymer represented by the following formula (a-1) is obtained by charging the polymerization reaction solution into a large amount of methanol / water (70/30 (mass ratio)) mixed solution and filtering the precipitate. It was. Mw of the obtained polymer (a-1) was 4,216.

[Example 2]
In Example 1, 4,4 ′-(α-methylbenzylidene) bisphenol 34.5 g (118.9 mmol), phenol 2.80 g (29.7 mmol) and paraformaldehyde 3.49 g were added to 4,4 ′-(α-methyl). Benzylidene) bisphenol 32.9 g (113.4 mmol), 1-naphthol 4.09 g (28.4 mmol) and paraformaldehyde 3.75 g were used in the same reaction scheme as in Example 1 to obtain the following formula (a-2 ) Was synthesized. Mw of the obtained polymer (a-2) was 3,006.

[Example 3]
In Example 1, 4,4 ′-(α-methylbenzylidene) bisphenol 34.5 g (118.9 mmol), phenol 2.80 g (29.7 mmol) and paraformaldehyde 3.49 g were added to 4,4 ′-(α-methyl). Benzylidene) bisphenol 28.7 g (99.0 mmol), bisphenolfluorene 8.67 g (24.7 mmol) and paraformaldehyde 3.28 g were used in the same reaction scheme as in Example 1 to obtain the following formula (a-3) Was synthesized. Mw of the obtained polymer (a-3) was 4,030.

[Example 4]
In Example 1, 4,4 ′-(α-methylbenzylidene) bisphenol 34.5 g (118.9 mmol), phenol 2.80 g (29.7 mmol) and paraformaldehyde 3.49 g were added to 4,4 ′-(α-methyl). Benzylidene) bisphenol 31.3 g (107.8 mmol), 1-hydroxypyrene 5.88 g (26.9 mmol) and paraformaldehyde 3.39 g were used in the same reaction scheme as in Example 1 to obtain the following formula (a- A polymer represented by 4) was synthesized. Mw of the obtained polymer (a-4) was 3,849.

[Example 5]
In Example 1, 34.5 g (118.9 mmol) of 4,4 ′-(α-methylbenzylidene) bisphenol, 2.80 g (29.7 mmol) of phenol and 3.49 g of paraformaldehyde were added to 4,4 ′-{1- [ 4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene} bisphenol 33.6 g (79.2 mmol), 1-hydroxypyrene 4.32 g (19.8 mmol) and paraformaldehyde 2.50 g A polymer represented by the following formula (a-5) was synthesized by the same reaction scheme as in Example 1 except for the change. Mw of the obtained polymer (a-5) was 3,602.

[Example 6]
In Example 1, 4,4 ′-(α-methylbenzylidene) bisphenol 34.5 g (118.9 mmol), phenol 2.80 g (29.7 mmol) and paraformaldehyde 3.49 g were added to 4,4 ′-(α-methyl). Benzylidene) bisphenol 17.5 g (60.4 mmol), 1-hydroxypyrene 8.78 g (40.2 mmol), phenol 9.47 g (100.6 mmol) and paraformaldehyde 4.76 g. The following polymer (a-6) was synthesized according to the reaction scheme of Mw of the obtained polymer (a-6) was 4,895.

[Example 7]
In Example 1, 4,4 ′-(α-methylbenzylidene) bisphenol 34.5 g (118.9 mmol), phenol 2.80 g (29.7 mmol) and paraformaldehyde 3.49 g were added to 4,4 ′-(α-methyl). Benzylidene) bisphenol 15.2 g (52.5 mmol), 1-hydroxypyrene 7.63 g (35.0 mmol), 1-naphthol 12.6 g (87.5 mmol) and paraformaldehyde 4.52 g (150.4 mmol) Except for the above, a polymer represented by the following formula (a-7) was synthesized according to the same reaction scheme as in Example 1. Mw of the obtained polymer (a-7) was 3,363.

[Example 8]
In Example 1, 34.5 g (118.9 mmol) of 4,4 ′-(α-methylbenzylidene) bisphenol, 2.80 g (29.7 mmol) of phenol and 3.49 g of paraformaldehyde were added to 4,4 ′-{1- [ 4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene} bisphenol 7.88 g (18.6 mmol), 1-hydroxypyrene 8.10 g (37.1 mmol), 1-naphthol 18.7 g A polymer represented by the following formula (a-8) was synthesized by the same reaction scheme as in Example 1 except that it was changed to (129.9 mmol) and 5.29 g (176.3 mmol) of paraformaldehyde. Mw of the obtained polymer (a-8) was 3,125.

[Example 9]
In Example 1, 4,4 ′-(α-methylbenzylidene) bisphenol 34.5 g (118.9 mmol), phenol 2.80 g (29.7 mmol) and paraformaldehyde 3.49 g were added to bis (4-hydroxyphenyl) diphenylmethane 16. 9.9 g (48.0 mmol), 1-hydroxypyrene 6.98 g (32.0 mmol), 1-naphthol 11.5 g (80.0 mmol) and paraformaldehyde 4.56 g (152.0 mmol) According to the same reaction scheme as in 1, a polymer represented by the following formula (a-9) was synthesized. Mw of the obtained polymer (a-9) was 2,885.

[Example 10]
In Example 1, 4,4 ′-(α-methylbenzylidene) bisphenol 34.5 g (118.9 mmol), phenol 2.80 g (29.7 mmol) and paraformaldehyde 3.49 g were added to 4,4 ′-(α-methyl). Benzylidene) bisphenol was implemented except that it was changed to 15.3 g (52.6 mmol), pyrene 7.09 g (35.1 mmol), 1-naphthol 12.6 g (87.6 mmol) and paraformaldehyde 5.00 g (166.5 mmol). A polymer represented by the following formula (a-10) was synthesized according to the same reaction scheme as in Example 1. Mw of the obtained polymer (a-10) was 2,646.

[Example 11]
In a three-necked flask equipped with a thermometer, a condenser and a mechanical stirrer, 13.4 g (45.9 mmol) of 4,4 ′-(α-methylbenzylidene) bisphenol and 6.61 g (45.9 mmol) of 1-naphthol were added under nitrogen. ) And 20.8 g (90.1 mmol) of 1-formylpyrene. Next, 60 g of propylene glycol monomethyl ether acetate (PGMEA) was added and dissolved, and then 4.40 g (23.1 mmol) of p-toluenesulfonic acid monohydrate was added and stirred at 130 ° C. for 8 hours for polymerization. did. Thereafter, the polymerization reaction solution is put into a large amount of methanol / water (70/30 (mass ratio)) mixed solution, and the precipitated compound is filtered to obtain a polymer represented by the following formula (a-11). It was. Mw of the obtained polymer (a-11) was 1,445.

[Example 12]
In Example 11, 1,3 g (45.9 mmol) of 4,4 ′-(α-methylbenzylidene) bisphenol, 6.61 g (45.9 mmol) of 1-naphthol and 20.8 g (90.1 mmol) of 1-formylpyrene were obtained. 4,4 ′-(α-methylbenzylidene) bisphenol 19.5 g (67.1 mmol), 1-hydroxypyrene 6.28 g (28.8 mmol), 1-naphthol 8.40 g (58.2 mmol) and 1-naphthaldehyde A polymer represented by the following formula (a-12) was synthesized by the same reaction scheme as in Example 11 except that the amount was changed to 14.2 g (91.1 mmol). Mw of the obtained polymer (a-12) was 2,202.

[Example 138]
In Example 1, 4,4 ′-(α-methylbenzylidene) bisphenol 34.5 g (118.9 mmol), phenol 2.80 g (29.7 mmol) and paraformaldehyde 3.49 g were added to 4,4 ′-(α-methyl). Benzylidene) bisphenol 28.7 g (99.0 mmol), bisnaphtholfluorene 11.1 g (24.7 mmol) and paraformaldehyde 3.28 g were used in the same reaction scheme as in Example 1 to obtain the following formula (a-13). ) Was synthesized. Mw of the obtained polymer (a-13) was 4,820.

[Example 139]
In Example 1, 4,4 ′-(α-methylbenzylidene) bisphenol 34.5 g (118.9 mmol), phenol 2.80 g (29.7 mmol) and paraformaldehyde 3.49 g were added to 4,4 ′-(α-methyl). Benzylidene) bisphenol 28.7 g (99.0 mmol), 2,7-dihydroxynaphthalene 3.4 g (24.7 mmol) and paraformaldehyde 3.28 g were used in the same reaction scheme as in Example 1 to obtain the following formula ( The polymer represented by a-14) was synthesized. Mw of the obtained polymer (a-14) was 3,510.

[Example 13]
A three-necked flask equipped with a thermometer, a condenser and a mechanical stirrer was charged with 20 g of the polymer (a-1) obtained above, 80 g of N, N-dimethylacetamide and 22.2 g (161 mmol) of potassium carbonate under nitrogen. It is. Next, the mixture was heated to 80 ° C., and 19.1 g (161 mmol) of propargyl bromide was added, followed by stirring for 6 hours to carry out the reaction. Thereafter, 40 g of methyl isobutyl ketone and 80 g of water were added to the reaction solution, and a liquid separation operation was performed. Then, the organic phase was poured into a large amount of methanol, and the precipitated compound was filtered to obtain the following formula (A-1 ) Was obtained. Mw of the obtained polymer (A-1) was 4,768.

[Example 14]
20 g of polymer (a-1), 22.2 g (161 mmol) of potassium carbonate and 19.1 g (161 mmol) of propargyl bromide in 20 g of polymer (a-2), 21.2 g (153 mmol) of potassium carbonate and A polymer represented by the following formula (A-2) was synthesized by the same reaction scheme as in Example 13 except that propargyl bromide was changed to 18.2 g (153 mmol). Mw of the obtained polymer (A-2) was 3,221.

[Example 15]
20 g of polymer (a-1), 22.2 g (161 mmol) of potassium carbonate and 19.1 g (161 mmol) of propargyl bromide in 20 g of polymer (a-3), 20.5 g (148 mmol) of potassium carbonate and A polymer represented by the following formula (A-3) was synthesized by the same reaction scheme as in Example 13 except for changing to 17.7 g (148 mmol) of propargyl bromide. Mw of the obtained polymer (A-3) was 4,426.

[Example 16]
20 g of polymer (a-1), 22.2 g (161 mmol) of potassium carbonate and 19.1 g (161 mmol) of propargyl bromide in 20 g of polymer (a-4), 20.1 g (146 mmol) of potassium carbonate and A polymer represented by the following formula (A-4) was synthesized by the same reaction scheme as in Example 13 except for changing to 17.3 g (146 mmol) of propargyl bromide. Mw of the obtained polymer (A-4) was 4,503.

[Example 17]
20 g of polymer (a-1), 22.2 g (161 mmol) of potassium carbonate and 19.1 g (161 mmol) of propargyl bromide in 20 g of polymer (a-5), 21.3 g (154 mmol) of potassium carbonate and A polymer represented by the following formula (A-5) was synthesized by the same reaction scheme as in Example 13 except for changing to 18.4 g (154 mmol) of propargyl bromide. Mw of the obtained polymer (A-5) was 4,121.

[Example 18]
20 g of polymer (a-1), 22.2 g (161 mmol) of potassium carbonate and 19.1 g (161 mmol) of propargyl bromide in 20 g of polymer (a-6), 21.7 g (157 mmol) of potassium carbonate and A polymer represented by the following formula (A-6) was synthesized by the same reaction scheme as in Example 13 except for changing to 18.7 g (157 mmol) of propargyl bromide. Mw of the obtained polymer (A-6) was 5,801.

[Example 19]
20 g of polymer (a-1), 22.2 g (161 mmol) of potassium carbonate and 19.1 g (161 mmol) of propargyl bromide in 20 g of polymer (a-7), 18.9 g (136 mmol) of potassium carbonate and A polymer represented by the following formula (A-7) was synthesized by the same reaction scheme as in Example 13 except that propargyl bromide was changed to 16.2 g (136 mmol). Mw of the obtained polymer (A-7) was 3,820.

[Example 20]
20 g of polymer (a-1) in Example 13, 22.2 g (161 mmol) of potassium carbonate and 19.1 g (161 mmol) of propargyl bromide, 20 g of polymer (a-8), 18.5 g (134 mmol) of potassium carbonate and A polymer represented by the following formula (A-8) was synthesized by the same reaction scheme as in Example 13 except that the propargyl bromide was changed to 15.9 g (134 mmol). Mw of the obtained polymer (A-8) was 3,536.

[Example 21]
20 g of polymer (a-1), 22.2 g (161 mmol) of potassium carbonate and 19.1 g (161 mmol) of propargyl bromide in 20 g of polymer (a-9), 17.2 g (125 mmol) of potassium carbonate and A polymer represented by the following formula (A-9) was synthesized by the same reaction scheme as in Example 13 except that the propargyl bromide was changed to 14.8 g (125 mmol). Mw of the obtained polymer (A-9) was 3,262.

[Example 22]
20 g of polymer (a-1), 22.2 g (161 mmol) of potassium carbonate and 19.1 g (161 mmol) of propargyl bromide in 20 g of polymer (a-10), 14.8 g (107 mmol) of potassium carbonate and A polymer represented by the following formula (A-10) was synthesized by the same reaction scheme as in Example 13 except that the amount was changed to 12.7 g (107 mmol) of propargyl bromide. Mw of the obtained polymer (A-10) was 2,967.

[Example 23]
20 g of polymer (a-1), 22.2 g (161 mmol) of potassium carbonate and 19.1 g (161 mmol) of propargyl bromide in 20 g of polymer (a-11), 10.2 g (74.0 mmol) of potassium carbonate ) And propargyl bromide were changed to 8.80 g (74.0 mmol), and a polymer represented by the following formula (A-11) was synthesized by the same reaction scheme as in Example 13. Mw of the obtained polymer (A-11) was 1,627.

[Example 24]
20 g of polymer (a-1), 22.2 g (161 mmol) of potassium carbonate and 19.1 g (161 mmol) of propargyl bromide in 20 g of polymer (a-12) and 12.6 g (90.9 mmol) of potassium carbonate ) And propargyl bromide were changed to 10.8 g (90.9 mmol), and a polymer represented by the following formula (A-12) was synthesized by the same reaction scheme as in Example 13. Mw of the obtained polymer (A-12) was 2,419.

[Example 25]
According to the same reaction scheme as in Example 19 except that 16.2 g (136 mmol) of propargyl bromide in Example 19 was changed to 16.4 g (136 mmol) of cyanomethyl bromide. A coalescence was synthesized. Mw of the obtained polymer (A-13) was 3,995.

[Example 140]
20 g of polymer (a-1), 22.2 g (161 mmol) of potassium carbonate and 19.1 g (161 mmol) of propargyl bromide in 24 g of polymer (a-13), 20.5 g (148 mmol) of potassium carbonate and A polymer represented by the following formula (A-14) was synthesized according to the same reaction scheme as in Example 13 except that the amount was changed to 17.7 g (148 mmol) of propargyl bromide. Mw of the obtained polymer (A-14) was 5,293.

  20 g of polymer (a-1), 22.2 g (161 mmol) of potassium carbonate and 19.1 g (161 mmol) of propargyl bromide in 18 g of polymer (a-14), 20.5 g (148 mmol) of potassium carbonate and A polymer represented by the following formula (A-15) was synthesized by the same reaction scheme as in Example 13 except for changing to 17.7 g (148 mmol) of propargyl bromide. Mw of the obtained polymer (A-15) was 3,854.

[Synthesis Example 1]
In Example 1, 4,4 ′-(α-methylbenzylidene) bisphenol 34.5 g (118.9 mmol), phenol 2.80 g (29.7 mmol) and paraformaldehyde 3.49 g were added to m-cresol 33.9 g (313 mmol). A polymer represented by the following formula (c-2) was synthesized by the same reaction scheme as in Example 1 except that the amount was changed to 6.89 g of paraformaldehyde. Mw of the obtained polymer (c-1) was 2,420.

[Synthesis Example 2]
In Example 1, 3,4.5 g (118.9 mmol) of 4,4 ′-(α-methylbenzylidene) bisphenol, 2.80 g (29.7 mmol) of phenol, and 3.49 g of paraformaldehyde were added to 37.9 g (108 mmol) of bisphenolfluorene and A polymer represented by the following formula (c-2) was synthesized by the same reaction scheme as in Example 1 except that the amount was changed to 2.86 g of paraformaldehyde. Mw of the obtained polymer (c-2) was 4,562.

<Preparation of composition for forming resist underlayer film>
Components other than the [A] polymer used for the preparation of the resist underlayer film forming composition are shown below.

([B] solvent)
B-1: Propylene glycol monomethyl ether acetate (PGMEA)

([C] acid generator)
C-1: Bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate (compound represented by the following formula (C-1))

([D] cross-linking agent)
D-1: 1,3,4,6-tetramethoxymethylglycoluril (compound represented by the following formula (D-1))

[Example 26]
[A] 5 parts by mass of (a-1) as a polymer was dissolved in 94.5 parts by mass of (B-1) as a [B] solvent. The obtained solution was filtered through a membrane filter having a pore size of 0.1 μm to prepare a resist underlayer film forming composition (J-1).

[Examples 27 to 56 and 142 to 145 and Comparative Examples 1 and 2]
Each composition for forming a resist underlayer film was prepared in the same manner as in Example 26 except that the components of the types and amounts shown in Table 1 were used. In Table 1, “-” indicates that the corresponding component was not used.

<Formation of resist underlayer film>
[Examples 57 to 106 and 146 to 149 and Comparative Examples 3 to 6]
Each of the prepared resist underlayer film forming compositions was applied on a silicon wafer substrate by a spin coating method. Thereafter, the substrate was heated (fired) at 220 ° C. for 60 seconds in an air atmosphere to form a resist underlayer film having a thickness of 200 nm, thereby obtaining a substrate with a resist underlayer film in which the resist underlayer film was formed on the substrate ( Examples 57-75 and comparative examples 3 and 4). In Examples 76 to 106 and 146 to 149 and Comparative Examples 5 and 6, substrates with resist underlayer films that were heated (baked) at 400 ° C. for 90 seconds were obtained.

<Formation of resist underlayer film on stepped substrate>
Each of the resist underlayer film forming compositions prepared above was applied onto a silicon wafer stepped substrate (substrate to be processed) having a 70 nm contact hole and 500 nm depth by spin coating. Thereafter, the substrate was heated (fired) at 220 ° C. for 60 seconds in an air atmosphere to form a resist underlayer film having a thickness of 200 nm, thereby obtaining a stepped substrate with a resist underlayer film in which the resist underlayer film was formed on the substrate. (Examples 57 to 75 and Comparative Examples 3 and 4). In Examples 76 to 106 and Comparative Examples 5 and 6, a stepped substrate with a resist underlayer film that was heated (baked) at 400 ° C. for 90 seconds was obtained.

<Evaluation>
Various evaluations were performed on the obtained resist underlayer film forming composition, the substrate with the resist underlayer film, and the stepped substrate with the resist underlayer film by the following procedures. The evaluation results are shown in Tables 2 and 3 below.

[Solvent resistance]
The obtained substrate with a resist underlayer film was immersed in cyclohexanone (room temperature) for 1 minute. The average film thickness before and after immersion is measured, the average film thickness before immersion is X0, the average film thickness after immersion is X, and the absolute value of the numerical value obtained by (X−X0) × 100 / X0 is calculated. The thickness change rate (%) was used. The solvent resistance is “A” (good) when the film thickness change rate is less than 1%, “B” (slightly good) when it is 1% or more and less than 5%, and “C” when it is 5% or more. (Poor).

[Etching resistance]
About the obtained substrate with a resist underlayer film, CF ₄ / Ar = 110/440 sccm, PRESS. Using an etching apparatus (“TACTRAS” manufactured by Tokyo Electron Ltd.). = 30MT, HF RF = 500W, LF RF = 3000W, DCS = -150V, RDC = 50%, RDC = 50%, processed for 30 sec, and calculated (nm / min) from the average film thickness before and after the process. The ratio was calculated. The etching resistance is “A” (very good) when the ratio is 0.95 or more and less than 0.98, “B” (good) when the ratio is 0.98 or more and less than 1.00, and 1.0 or more. In the case of, it was evaluated as “C” (defective).

[Heat-resistant]
The prepared resist underlayer film forming composition was spin-coated on a silicon wafer having a diameter of 8 inches to form a resist underlayer film, thereby obtaining a substrate with a resist underlayer film. The powder was collected from the substrate with the resist underlayer film, and the powder was put in a container, and the mass before heating was measured. Next, this resist underlayer film was heated at 400 ° C. for 150 seconds. After recovering the powder from the substrate, using a TG-DTA apparatus ("TG-DTA2000SR" manufactured by NETZSCH), it is heated to 400 ° C at a temperature rising rate of 10 ° C / min in a nitrogen atmosphere. The mass of the powder was measured. And mass reduction rate (%) was measured by the following formula, and this mass reduction rate was used as a measure of heat resistance.
M _L = {(m1−m2) / m1} × 100
Here, in the above formula, _{M L} is a mass reduction rate (%), m1 is the pre-heating the mass (mg), m @ 2 is the mass (mg) at 400 ° C..
The heat resistance is better as the mass reduction rate of the powder as the sample is smaller, because there are fewer sublimates and decomposition products of the resist underlayer film that are generated when the resist underlayer film is heated. That is, the smaller the mass reduction rate, the higher the heat resistance. The heat resistance is “A” (very good) when the mass reduction value is less than 5%, “B” (good) when it is 5% or more and less than 10%, and “C” (when it is 10% or more). Bad).

[Embeddability]
The cross-sectional shape of the obtained stepped substrate with a resist underlayer film was observed with a scanning electron microscope ("S-4800" manufactured by Hitachi High-Technologies Corporation), and the presence or absence of poor embeddability (void) was evaluated. A case where no void was observed was evaluated as “A” (good), and a case where a void was observed was evaluated as “B” (bad).

[Edge rinse]
[Examples 107 to 137 and 150 to 153 and Comparative Examples 7 and 8]
Propylene glycol monomethyl ether acetate (PGMEA) was ejected from the nozzle for 15 seconds to the edge portion of the substrate while the substrate coated with the resist underlayer film forming composition obtained was rotated at 1000 rpm. Thereafter, the substrate was rotated at 1000 rpm for 10 seconds. About the obtained board | substrate, the remaining film of the board | substrate edge part was evaluated. The case where the remaining film was not recognized was evaluated as “A” (good), and the case where the remaining film was observed was evaluated as “B” (bad).

  As can be seen from the results in Tables 2 and 3, according to the resist underlayer film forming compositions of the examples, PGMEA or the like can be used as a solvent, and edge rinse, solvent resistance, etching resistance, heat resistance and embedding are possible. A resist underlayer film having excellent properties can be formed.

  According to the composition for forming a resist underlayer film of the present invention, PGMEA or the like can be used as a solvent, and a resist underlayer film excellent in edge rinse, solvent resistance, etching resistance, heat resistance, and embedding property can be formed. . The resist underlayer film of the present invention is excellent in edge rinse, solvent resistance, etching resistance, heat resistance and embedding property. According to the method for producing a patterned substrate of the present invention, a patterned substrate having an excellent pattern shape can be obtained by using the excellent resist underlayer film formed as described above. Therefore, these can be suitably used for manufacturing semiconductor devices and the like that are expected to be further miniaturized in the future.

Claims (9)

A polymer for forming a resist underlayer film having a first repeating unit represented by the following formula (1).

(In the formula (1), Ar ¹ , Ar ² and Ar ³ are each independently a substituted or unsubstituted arenediyl group having 6 to 30 carbon atoms. R ¹ is a substituted or unsubstituted carbon number 1 A divalent hydrocarbon group of ˜30, n is 0 or 1. R ² is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted carbon number of 6; R ³ is a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms, and R ⁴ is a hydrogen atom or a substituted or unsubstituted carbon atom having 1 to 3 carbon atoms. 30 monovalent hydrocarbon group.) The polymer for forming a resist underlayer film according to claim 1, further comprising a second repeating unit which is a repeating unit different from the first repeating unit and represented by the following formula (2).

(In Formula (2), Ar ⁴ is a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. R ⁵ is a hydrogen atom or a substituted or unsubstituted carbon atom having 1 to 30 carbon atoms. Of the monovalent hydrocarbon group.)   2. A compound having at least one selected from a hydroxy group, an alkoxy group, a monovalent group containing a carbon-carbon double bond, a monovalent group containing a carbon-carbon triple bond, and a monovalent group containing a cyano group. Alternatively, the polymer for forming a resist underlayer film according to claim 2.   The polymer for forming a resist underlayer film according to claim 3, wherein the monovalent group containing a carbon-carbon triple bond is a propargyloxy group.   The polymer for forming a resist underlayer film according to any one of claims 1 to 4, having a weight average molecular weight of 1,000 or more and 10,000 or less. The polymer for forming a resist underlayer film according to any one of claims 1 to 5,
A composition for forming a resist underlayer film comprising an organic solvent.   A resist underlayer film formed from the composition for forming a resist underlayer film according to claim 6. Forming a resist underlayer film on one side of the substrate;
Forming a resist pattern on the opposite side of the resist underlayer film from the substrate;
Forming a pattern on the substrate by multiple etchings using the resist pattern as a mask,
A method for producing a patterned substrate, wherein the resist underlayer film is formed from the resist underlayer film forming composition according to claim 6. A method for producing a polymer for forming a resist underlayer film comprising a step of reacting a compound represented by the following formula (3) with a compound represented by the following formula (4).

(In Formula (3), Ar ^{1 ′} and Ar ^{3 ′} are each independently a substituted or unsubstituted aryl group having 6 to 30 carbon atoms. Ar ² is a substituted or unsubstituted carbon group having 6 to 6 carbon atoms. 30 is an arenediyl group, R ¹ is a divalent hydrocarbon group having 1 to 30 carbon atoms, n is 0 or 1. R ² is a hydrogen atom, substituted or unsubstituted carbon number 1 Or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and R ³ is a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms.
In formula (4), R ⁴ is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 30 carbon atoms. )