JP6907522B2 - A composition for forming a resist underlayer film and a method for producing the same, a method for producing a resist underlayer film and a patterned substrate. - Google Patents

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 method for producing a resist underlayer film, and 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 surface side of the substrate to form a resist underlayer film, and then the resist composition is applied to the surface side of the resist underlayer film opposite to the substrate. Form a resist film. Then, the resist film is exposed through a mask pattern or the like and developed with an appropriate developing solution 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 to form a desired pattern on the substrate to obtain a patterned substrate. Can be done. The resist underlayer film used in such a multilayer resist process is required to have optical properties such as refractive index and extinction coefficient, and general properties such as solvent resistance and etching resistance.

In recent years, the pattern has been further miniaturized in order to further increase the degree of integration, and even in the above-mentioned multilayer resist process, the resist underlayer film and the composition for forming the resist are excellent in various properties as described below. 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-A-2004-177668).

In the above-mentioned conventional resist underlayer film forming composition, the compound contained therein generally has low solubility in a solvent such as propylene glycol monomethyl ether acetate (PGMEA) due to its structure and the like. Therefore, there is a disadvantage that the coatability on the substrate is poor, and as a result, it is difficult to form a uniform resist underlayer film.

Further, recently, in the above-mentioned multilayer resist process, a method of forming a hard mask as an intermediate layer on a 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. Therefore, in the case of a nitride-based inorganic hard mask, the temperature is at least 300 ° C., usually 400 ° C. or higher, and therefore the resist is used. The underlayer film requires high heat resistance. However, the resist underlayer film formed from the above-mentioned conventional resist underlayer film forming composition has insufficient heat resistance, and the components of the resist underlayer film sublimate, and the sublimated components reattach to the substrate to form a semiconductor device. There is an inconvenience that the manufacturing yield of the product is lowered.

Japanese Unexamined Patent Publication No. 2004-177668

Furthermore, in recent years, there have been increasing cases where patterns are formed on a substrate having a plurality of types of trenches, particularly trenches having different aspect ratios from each other, 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 resist underlayer film forming composition, such embedding property is insufficient, and the resist underlayer film to be formed and the hard mask have cavities (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 above circumstances, and an object of the present invention is to use a resist such as PGMEA as a solvent, which is excellent in edge rinse property, solvent resistance, etching resistance, heat resistance and embedding property. It is an object of the present invention to provide a polymer for forming a resist underlayer film capable of forming an underlayer film, a method for producing a polymer for forming a resist underlayer film, a composition for forming a resist underlayer film, a method for producing a resist underlayer film, and a patterned substrate.

（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 to solve the above problems is a polymer for forming a resist underlayer film (hereinafter, also referred to as “repetition unit (I)”) having a first repeating unit represented by the following formula (1). It is also referred to as "[A] polymer").

(In the formula (1), Ar ¹ , Ar ² and Ar ³ are independently substituted or unsubstituted arelane diyl groups having 6 to 30 carbon atoms. R ¹ is substituted or unsubstituted carbon number 1 It is a divalent hydrocarbon group of ~ 30. N is 0 or 1. R ² is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms substituted or unsubstituted, or a substituted or unsubstituted carbon number 6 R ³ is a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. R ⁴ is a hydrogen atom, substituted or unsubstituted carbon number 1 to 1. An alkyl group of 10 or a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms.)

Another invention made to solve the above problems contains the resist underlayer film forming polymer ([A] polymer) and an organic solvent (hereinafter, also referred to as “[B] organic solvent”). It is a composition for forming a resist underlayer film.

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

Yet another invention made to solve the above problems is a step of forming a resist underlayer film on one surface side of a substrate and a step of forming a resist pattern on the surface side of the resist underlayer film opposite to the substrate. A method for producing a patterned substrate, which comprises a step of forming a pattern on a substrate by a plurality of etchings using the resist pattern as a mask, and forming the resist underlayer film with the resist underlayer film forming composition. be.

（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。） Yet another invention made to solve the above problems is a polymer for forming a resist underlayer film, which comprises a step of reacting a compound represented by the following formula (3) with a compound represented by the following formula (4). It is a manufacturing method of.

(In the formula (3), Ar ^{1 'and} Ar ^3' are each independently, .Ar ² is a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted carbon atoms 6 It is an arylene diyl group of 30. 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 It is an alkyl group of 10 to 10 or an aryl group having 6 to 30 carbon atoms substituted or unsubstituted. R ³ is a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms substituted or unsubstituted.
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 resist underlayer film forming composition of the present invention, PGMEA or the like can be used as a solvent, and a resist underlayer film having excellent edge rinse property, 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 property, 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 formed excellent resist underlayer film. Therefore, these can be suitably used for manufacturing semiconductor devices and the like, which are expected to be further miniaturized in the future.

<[A] Polymer>
[A] The polymer is a polymer having a repeating unit (I). [A] In addition to the repeating unit (I), the polymer may contain 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) or the like showing a repeating unit of the polymer, [A] polymer ^{Ar 1 '- (R 1 -Ar} 2) n -CR 2 R 3 -Ar 3' (Ar 1 ' and Ar for ^{3 'is} indicative that it is formed from a compound represented by the later-described), and R ⁴ CHO. For example, those in which R ² and R ³ in the formula (1) are combined with 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 independently substituted or unsubstituted arelane diyl groups 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, an alkyl group having 1 to 10 carbon atoms substituted or unsubstituted, or an aryl group having 6 to 30 carbon atoms substituted or unsubstituted. 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.

Examples of the arene diyl group having 6 to 30 carbon atoms represented by Ar ¹ , Ar ² and Ar ³ include arenes having 6 to 30 carbon atoms such as benzene, naphthalene, anthracene, phenanthrene, pyrene, chrysene, tetracene, perylene and pentacene. Examples thereof include a group obtained by removing two hydrogen atoms from the group.

Examples of the substituent of the arenediyl group include a monovalent group containing an alkyl group, a hydroxy group, an alkoxy group and a cyano group, a monovalent group containing a carbon-carbon triple bond, and a monovalent group containing a carbon-carbon double bond. Group, fluorine atom, chlorine atom, bromine atom, halogen atom such as iodine atom and the like can be mentioned.

More specifically, Ar ¹ , Ar ² and Ar ³ are groups represented by, for example, the following formulas (5), (6), (7) and (8) (hereinafter, "groups (5)), respectively. , "Group (6)", "Group (7)" and "Group (8)") and the like.

In the above formulas (5) to (8), R ^{6 to} R ⁹ are a monovalent group containing an alkyl group, a hydroxy group, an alkoxy group and a cyano group, a monovalent group containing a carbon-carbon triple bond, and carbon-. It is a monovalent group or halogen atom containing a carbon double bond. * Indicates a bond.
In the above equation (5), c1 is an integer of 0 to 4. If c1 is 2 or more, plural R ⁶ may be the same or different. r1 is 2.
In the above equation (6), c2 is an integer of 0 to 6. If c2 is 2 or more, plural R ⁷ may be the same or different. r2 is 2.
In the above equation (7), c3 is an integer from 0 to 8. If c3 is 2 or more, plural R ⁸ may be the same or different. r3 is 2.
In the above equation (8), c4 is an integer from 0 to 8. If c4 is 2 or more, a 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 a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, and the like. A decyl group and the like can be mentioned.

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

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, and examples thereof include a cyanomethyl group, a cyanoethyl group, and a cyanopropyl group. Cyanalkyl groups such as groups, cyanobutyl groups, cyanopentyl groups, cyanohexyl groups, cyanooctyl groups, cyanodecyl groups: cyanomethyloxy groups, cyanoethyloxy groups, cyanopropyloxy groups, cyanobutyloxy groups, cyanopentyloxy groups, cyano Examples thereof include cyanoalkyloxy groups such as hexyloxy group, cyanooctyloxy group and 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, and examples thereof include an ethynyl group. , Propargyl group, 3-butynyl group, 2-butynyl group, 4-pentynyl group, 5-hexynyl group and other alkynyl groups; ethynyloxy group, propargyloxy group, 3-butynyloxy group, 2-butynyloxy group, 4-pentynyl Examples thereof include an alkynyloxy group such as an oxy group and a 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. Alkenyl groups 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 , 4-Pentenyloxy group, 5-hexenyloxy group and other alkenyloxy groups; phenylethenyl group, phenylpropenyl group and other groups containing aromatic rings and double bonds.

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

As the above R ^{6 to} R ⁹ , a monovalent group containing a carbon-carbon triple bond and a monovalent group containing a cyano group are preferable. 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 improved crosslinkability by having a group containing a carbon-carbon triple bond and / or a monovalent group containing a cyano group, and as a result, the solvent resistance, etching resistance, and heat resistance of the resist underlayer film are improved. And the embedding property can be improved.

As the above c1, 1 is preferable. As the above c2, 1 is preferable. As the above c3, 0 and 1 are preferable, and 0 is more preferable. As the c4, 0 and 1 are preferable, and 0 is more preferable.

Examples of the divalent hydrocarbon group having 1 to 30 carbon atoms represented by R ¹ in the formula (1), methylene bridge, ethanediyl group, propanediyl, butanediyl group, pentanediyl group, hexanediyl group, octane-diyl , Divalent chain hydrocarbon groups such as alkandyl groups such as decandyl group, tetradecandyl group, octadecandyl group and icosandyl group. Among these, a methanediyl group, an ethanediyl group, a propanediyl group and a butanjiyl group are preferable, and a methanediyl group and an ethanediyl group are more preferable.

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

Examples of the alkyl group having 1 to 10 carbon atoms represented by R ² in the formula (1), for example, mentioned a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, decyl group Be done.

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

Examples of the substituents of the alkyl group and the aryl group include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, and hydroxy group.

Examples of the alkyl group having 1 to 10 carbon atoms which is substituted with a fluorine atom represented by R ² in the formula (1), a fluoromethyl group, a trifluoromethyl group, perfluoroethyl group, fluorine such as perfluoro propyl Examples thereof include an alkylated group.

^{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 tetrasenyl group, a perylenel group and a pentasenyl group. And so on.

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

More specifically, examples of the above R ³ include groups in the above equations (5) to (8) when r1 to r4 are 1.

Examples of the monovalent hydrocarbon group having 1 to 30 carbon atoms represented by R ⁴ in the formula (1), for example, chain hydrocarbon groups such as a methyl group, an ethyl group, an alkyl group such as propyl group;
Alicyclic hydrocarbon groups such as cycloalkyl groups such as cyclopentyl group, cyclohexyl group and norbornyl group;
Examples thereof include aromatic hydrocarbon groups such as aryl groups such as phenyl group, naphthyl group, anthryl group, phenanthryl group, pyrenyl group and tetrasenyl 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. Examples include groups, hydroxy groups, halogen atoms and the like.

The repeating unit (I) is represented by, for example, a repeating unit represented by the following formula (1-1) (hereinafter, also referred to as “repeating unit (I-1)”) or the following formula (1-2). Examples thereof include a repeating unit (hereinafter, also referred to as a “repeating unit (I-2)”).

In the above formulas (1-1) and (1-2), R ⁴ has the same meaning as the above formula (1).
In the above formula (1-1), ^RX1 and ^RY1 are independently a monovalent group containing an alkyl group, a hydroxy group, an alkoxy group and a cyano group, and 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 independently integers from 0 to 4. When i1 is 2 or more, a plurality of ^RX1s may be the same or different. When j1 is 2 or more, a plurality of ^RY1s may be the same or different. R ^V1 is synonymous with ^{R 2} in the above formula (1). R ^W1 has the same meaning as ^{R 3} in the formula (1).
In the above formula (1-2), ^RX2 , ^RY2 and ^RZ2 each independently contain a monovalent group containing an alkyl group, a hydroxy group, an alkoxy group and a cyano group, and a carbon-carbon triple bond 1 A valent group, a monovalent group containing a carbon-carbon double bond, a halogen atom, or the like. i2, j2 and k2 are independently integers from 0 to 4. When i2 is 2 or more, a plurality of ^RX2s may be the same or different. When j2 is 2 or more, a plurality of ^RY2s may be the same or different. When k2 is 2 or more, a plurality of R ^Z2s may be the same or different. R ^V2 and ^RW2 are independently substituted or unsubstituted monovalent hydrocarbon groups having 1 to 20 carbon atoms. R ^V3 is synonymous with ^{R 2} in the above formula (1). R ^W3 is synonymous with ^{R 3} in the above formula (1).

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

The i1, i2, j1 and k2 are preferably 0 to 2, more preferably 0 and 1, and even more preferably 1. The j2 is preferably 0 to 2, more preferably 0 and 1, and even more preferably 0.

As R ^V1 , R ^V2 , R ^V3 , ^RW1 , ^RW2 and ^RW3 , alkyl groups and substituted and unsubstituted aryl groups are preferable, and alkyl groups, aryl groups, hydroxy-substituted aryl groups and carbon-carbon triple bonds are used. Aryl groups substituted with monovalent groups containing are more preferred, alkyl groups, aryl groups, hydroxy-substituted aryl groups and propargyloxy group-substituted aryl groups are even more preferred, methyl groups, phenyl groups, hydroxyphenyl groups and propargyloxyphenyl groups. Is particularly preferable.

The R ^4, a hydrogen atom, a methyl group, an ethyl group, a propyl group, a cyclopentyl group, a cyclohexyl group, a phenyl group, a naphthyl group, anthryl group, phenanthryl group, pyrenyl group and a tetracenyl group preferably a hydrogen atom, a methyl group, phenyl More preferred are groups, naphthyl, anthryl, phenyl and pyrenyl groups.

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

As the lower limit of the content ratio of the repeating unit (I), 10 mol% is preferable, 20 mol% is more preferable, 30 mol% is further preferable, and 40 mol% is more preferable with respect to all the repeating units constituting the polymer [A]. % Is particularly preferable. The upper limit of the content ratio is preferably 100 mol%, more preferably 85 mol%, still more preferably 80 mol%. By setting the content ratio of the repeating unit (I) in 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 the above 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 monovalent hydrocarbon group having 1 to 30 carbon atoms.

As the substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms represented by ^{Ar 4} , the substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms exemplified as ^{R 3 above is used.} Examples thereof include a group obtained by removing one hydrogen atom from a group 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, the divalent aromatic hydrocarbon group having 6 to 30 carbon atoms represented by Ar ⁴ includes, for example, a benzenediyl group, a naphthalenediyl group, an anthracendyl group, a phenanthrenidyl group, and a pyrenediyl group. Examples thereof include a chrysendiyl group, a tetrasendiyl group, a perylenediyl group, a pentasendiyl group, and a full-orangeyl group. More specifically, for example, the groups represented by the above formulas (5) to (8), the groups represented by the following formula (9) (hereinafter, also referred to as "group (9)"), and the formula (10). Examples thereof include a represented group (hereinafter, also referred to as “group (10)”).

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

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

As a ^{monovalent group containing an alkyl group, an alkoxy group, and a cyano group represented by R 10 to} R ¹⁷ , a monovalent group containing a carbon-carbon triple bond, and a monovalent group containing a carbon-carbon double bond. For example, the same group as the same group exemplified as ^{R 6 to} R ^{9 above can be mentioned.}

As the R ^{10 to} R ¹⁷ , monovalent groups containing a carbon-carbon triple bond and monovalent groups containing a cyano group are preferable. 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 improved crosslinkability by having a group containing a carbon-carbon triple bond and / or a monovalent group containing a cyano group, and as a result, the solvent resistance, etching resistance, and heat resistance of the resist underlayer film are improved. And the embedding property can be improved.

As m1 and m2 in the above formula (9), 0 and 1 are preferable. As a1 and a2, an integer of 0 to 2 is preferable, 0 and 1 are more preferable, and 1 is further preferable. As a3 and a4, an integer of 0 to 2 is preferable, 0 and 1 are more preferable, and 0 is further 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 further 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)"). Be 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)"). Be done.

In the above formulas (9-1) to (9-5), ^RA independently contains an alkyl group, a hydroxy group, an alkoxy group, a monovalent group containing a cyano group, and a carbon-carbon triple bond1 A valent group or a monovalent group containing a carbon-carbon double bond. p1 to p4 are synonymous with the above formula (9). * Indicates a binding site with a portion other than the groups (9-1) to (9-5) in the [A] polymer.

In the above formulas (10-1) to (10-4), ^RA independently contains an alkyl group, a hydroxy group, an alkoxy group, a monovalent group containing a cyano group, and a carbon-carbon triple bond1 A valent group or a monovalent group containing a carbon-carbon double bond. q1 to q4 are synonymous with the above formula (10). * Indicates a binding site with a portion other than the groups (10-1) to (10-4) in the [A] polymer.

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

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

When the repeating unit (II) has at least one of the groups (5) to (8), the lower limit of the total content ratio of the repeating units including the groups (5) to (8) is [A. ] With respect to all the repeating units constituting the polymer, 10 mol% is preferable, 20 mol% is more preferable, and 30 mol% is further preferable. The upper limit of the content ratio is preferably 90 mol%, more preferably 80 mol%, still more preferably 70 mol%. By setting the total content ratio of the repeating units containing the groups (5) to (8) in the above range, the solubility of the [A] polymer in the solvent can be further enhanced, and as a result, the resist underlayer film can be further enhanced. The edge rinse property and embedding property of the solvent can be further improved.

When the repeating unit (II) has a group (9) or a group (10), the lower limit of the total content ratio of the repeating unit containing the group (9) or the group (10) constitutes the [A] polymer. 10 mol% is preferred, 20 mol% is more preferred, and 30 mol% is even more preferred with respect to all repeating units. The upper limit of the content ratio is preferably 90 mol%, more preferably 80 mol%, still more preferably 70 mol%. By setting the content ratio of the repeating unit containing the group (9) or the group (10) in the above range, the content rate of the polycyclic structure in the polymer [A] can be increased, and as a result, the resist underlayer film Both heat resistance and embedding property can be achieved at a higher level.

As the lower limit of the content ratio of the repeating unit (II), 10 mol% is preferable, 20 mol% is more preferable, 30 mol% is further preferable, and 40 mol% is more preferable with respect to all the repeating units constituting the polymer [A]. % Is particularly preferable. The upper limit of the content ratio is preferably 90 mol%, more preferably 80 mol%, still more preferably 70 mol%. By setting the content ratio of the repeating unit (II) in the above range, the heat resistance and embedding property of the resist underlayer film can be further improved.

When the [A] 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 the all repeating units constituting the [A] polymer. On the other hand, 1 mol% is preferable, 5 mol% is more preferable, and 10 mol% is further preferable. The upper limit of the content ratio is preferably 60 mol%, more preferably 50 mol%, further preferably 40 mol%, and particularly preferably 30 mol%. By setting the content ratio of the other repeating units in the above range, the solvent resistance, etching resistance, heat resistance and embedding property of the resist underlayer film can be further improved.

Examples of the polymer [A] 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, and 85% by mass, based on the total solid content (components other than the solvent) in the composition for forming the resist underlayer film. Mass% is more preferred. For the solid content concentration, 0.5 g of the resist underlayer film forming composition was fired at 250 ° C. for 30 minutes to measure the mass of the solid content with respect to 0.5 g of the resist underlayer film forming composition, and the resist underlayer film was formed. It is obtained by calculating the solid content concentration (mass%) of the composition for use.

<[A] Polymer production method>
The polymer [A] can be synthesized by a known method. When the polymer [A] 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 precursor compound such as a compound represented by (3) and a compound represented by the following formula (4) is reacted in a solvent such as propylene glycol monomethyl ether acetate in the presence of an acid to obtain a polymer. Can be done. This polymer further comprises the obtained polymer and a compound such as propargyl bromide that forms a monovalent group containing a carbon-carbon triple bond in the presence of a base, such as N, N-dimethylacetamide. By reacting in a solvent, the [A] polymer containing a carbon-carbon triple bond or the like can be synthesized. One or two or more of the precursor compounds can be used, and the ratio of the precursor compounds to be used can be appropriately selected depending on the desired performance of the resist underlayer film and the like. Further, the ratio of the compound represented by the following formula (3) to the aldehyde in the precursor compound can be appropriately selected depending on the desired performance of the resist underlayer film and the like.

In the 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 arrestedyl 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, an alkyl group having 1 to 10 carbon atoms substituted or unsubstituted, or an aryl group having 6 to 30 carbon atoms substituted or unsubstituted. R ³ is a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms.
In the above formula (4), R ⁴ is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 30 carbon atoms.

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

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

As the lower limit of the amount of acid used, 1 mol is preferable and 5 mol is more preferable with respect to 1 mol of aldehyde. The upper limit of the amount used is preferably 20 mol, more preferably 10 mol.

The lower limit of the reaction temperature of the synthesis reaction of the polymer having a phenolic hydroxyl group is preferably 60 ° C., more preferably 80 ° C. The upper limit of the reaction temperature is preferably 150 ° C., more preferably 120 ° C. The lower limit of the reaction time of the above reaction is preferably 1 hour, more preferably 4 hours. The upper limit of the reaction time is preferably 24 hours, 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. ; Examples include alkali metal hydrides such as lithium hydride, sodium hydride, and potassium hydride. Among these, alkali metal carbonate is preferable, and potassium carbonate is more preferable.

The lower limit of the amount of the base used is preferably 0.1 mol, more preferably 0.5 mol, and more preferably 0.8 mol, based on 1 mol of the compound forming a monovalent group containing the carbon-carbon triple bond. Is even more preferable. As the upper limit of the amount used, 3 mol is preferable, 2 mol is more preferable, and 1.5 mol is further preferable.

The lower limit of the reaction temperature of the reaction of reacting the above polymer with a compound or the like forming a monovalent group containing a carbon-carbon triple bond to obtain a [A] polymer containing a carbon-carbon triple bond or the like is 50. ℃ is preferable, and 60 ° C is more preferable. The upper limit of the reaction temperature is preferably 130 ° C., more preferably 100 ° C. The lower limit of the reaction time of the above reaction is preferably 1 hour, more preferably 4 hours. The upper limit of the reaction time is preferably 24 hours, more preferably 12 hours.

The [A] polymer obtained by synthesis can be purified from the reaction solution by liquid separation operation, reprecipitation, recrystallization, distillation and the like. Polymers [A] 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, 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. The weight average molecular weight (Mw) is a polystyrene-equivalent weight average molecular weight (Mw) obtained by gel permeation chromatography (GPC).

By setting the molecular weight of the polymer in 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] As the upper limit of the ratio (Mw / Mn ratio) of the polymer to the number average molecular weight (Mn) of Mw, 5 is preferable, 3 is more preferable, 2 is more preferable, and 1.8 is particularly preferable. The lower limit of the ratio is usually 1, preferably 1.2. 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 a resist underlayer film>
The resist underlayer film forming composition contains the [A] polymer and the [B] organic solvent. The composition for forming a resist underlayer film may contain an acid generator [C] as a suitable component, or 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>
The polymer [A] is a polymer for forming a resist underlayer film having a repeating unit (I) represented by the above formula (1). The polymer [A] is described above.

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

Examples of the solvent [B] include alcohol solvents, ketone solvents, ether solvents, ester solvents, nitrogen-containing solvents and the like. [B] The solvent may be used alone or in combination of two or more.

Examples of the alcohol-based solvent include methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, tert-butanol, n-pentanol, iso-pentanol, 2-methylbutanol, and the like. sec-pentanol, tert-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol , Se-octanol, n-nonyl alcohol, 2,6-dimethylheptanol-4, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl alcohol, phenol, cyclohexanol , Methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, phenylmethylcarbinol, diacetone alcohol, cresol and other monoalcoholic solvents; 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-hexanediol, diethylene glycol, dipropylene glycol , Triethylene glycol, tripropylene glycol, polyhydric alcohol-based solvents such as glycerin and the like.

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, and methyl-n-. Examples thereof include hexyl ketone, di-iso-butyl ketone, trimethylnonanone, cyclohexanone, methylcyclohexanone, 2,4-pentandione, acetonylacetone, diacetone alcohol, acetophenone and fenchone.

Examples of the ether-based solvent 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, and the like. 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, diethylene 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 ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl Examples thereof include ether, tripropylene glycol monomethyl ether, tetrahydrofuran, 2-methyl tetrahydrofuran and the like.

Examples of the ester solvent 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, and the like. N-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methylcyclohexyl acetate, n-nonyl acetate, methyl acetoacetate, aceto Ethyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene acetate Glycol monopropyl ether, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, glycol diacetate, methoxytriglycol acetate, 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, dimethyl phthalate, diethyl phthalate and the like.

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

Among these, an ether solvent and an ester solvent are preferable, and a glycol solvent is more preferable from the viewpoint of excellent film forming property.

Examples of the glycol-based solvent include propylene glycol monomethyl ether, prolen 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, further preferably 90% by mass, and particularly preferably 100% by mass.

<[C] Acid generator>
The [C] acid generator is a component that generates an acid by the action of heat or light and promotes the cross-linking of the [A] polymer. When the resist underlayer film forming composition contains the [C] acid generator, the cross-linking reaction of the [A] polymer is promoted, and the hardness of the formed film can be further increased. [C] The acid generator can be used alone or in combination of two or more.

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

Examples of the onium salt compound include a sulfonium salt, a tetrahydrothiophenium salt, an iodonium salt and the like.

Examples of the sulfonium salt include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, and triphenylsulfonium 2-bicyclo [2.2.1] hept-. 2-Il-1,1,2,2-tetrafluoroethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-cyclohexylphenyldiphenylsulfonium perfluoro- n-octane sulfonate, 4-cyclohexylphenyldiphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium trifluoromethanesulfonate , 4-Methanesulfonylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium 2-bicyclo [2.2.1] hept- Examples thereof include 2-yl-1,1,2,2-tetrafluoroethanesulfonate.

Examples of the tetrahydrothiophenium salt include 1- (4-n-butoxynaphthalene-1-yl) tetrahydrothiophenium trifluoromethanesulfonate and 1- (4-n-butoxynaphthalene-1-yl) tetrahydrothiophenium nona. Fluoro-n-butane sulfonate, 1- (4-n-butoxynaphthalene-1-yl) tetrahydrothiophenium perfluoro-n-octane sulfonate, 1- (4-n-butoxynaphthalene-1-yl) tetrahydrothiophene Nium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (6-n-butoxynaphthalene-2-yl) tetrahydrothiophenium trifluoromethane Ssulfonate, 1- (6-n-butoxynaphthalene-2-yl) tetrahydrothiophenium nonafluoro-n-butane sulfonate, 1- (6-n-butoxynaphthalene-2-yl) tetrahydrothiophenium perfluoro-n -Octane sulfonate, 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-butane sulfonate, 1 -(3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2-bicyclo [2.2] .1] Hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate and the like can be mentioned.

Examples of the iodonium salt include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butane sulfonate, diphenyliodonium perfluoro-n-octane sulfonate, and 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-tetrafluoroethane Examples include sulfonate.

Examples of the N-sulfonyloxyimide compound include N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboxyimide and N- (nonafluoro-n-butanesulfonyloxy). ) Bicyclo [2.2.1] hept-5-en-2,3-dicarboxyimide, N- (perfluoro-n-octanesulfonyloxy) bicyclo [2.2.1] hept-5-en-2 , 3-Dicarboxyimide, N- (2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonyloxy) bicyclo [2.2.1] hept- Examples thereof include 5-en-2 and 3-dicarboxyimide.

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-butane sulfonate is further preferable.

When the resist underlayer film forming composition contains the [C] acid generator, the lower limit of the content of the [C] acid generator is 0.1 mass by mass with respect to 100 parts by mass of the [A] polymer. Part is preferable
1 part by mass is more preferable, and 3 parts by mass is further preferable. The upper limit of the content is preferably 20 parts by mass, more preferably 15 parts by mass, and even more preferably 10 parts by mass. By setting the content of the [C] acid generator in the above range, the cross-linking reaction of the [A] polymer can be promoted more effectively.

<Other optional ingredients>
Examples of other optional components of the resist underlayer film forming composition include a cross-linking agent, a surfactant, and an adhesion aid.

[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 or acid. When the resist underlayer film forming composition contains a cross-linking agent, the hardness of the formed film can be increased. The cross-linking agent may be used alone or in combination of two or more.

Examples of the cross-linking agent include a polyfunctional (meth) acrylate compound, an epoxy compound, a hydroxymethyl group-substituted phenol compound, an alkoxyalkyl group-containing phenol compound, a compound having an alkoxyalkylated amino group, and the following formula (11-P). Examples thereof include a random copolymer of acenaphtylene represented by hydroxymethyl acenaphthylene, and compounds represented by the following formulas (11-1) to (11-12).

Examples of the polyfunctional (meth) acrylate compound include trimethylolpropantri (meth) acrylate, ditrimethylolpropanetetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and dipentaerythritol penta. (Meta) 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 Examples thereof include (meth) acrylate, dipropylene glycol di (meth) acrylate, and bis (2-hydroxyethyl) isocyanurate di (meth) acrylate.

Examples of the epoxy compound include novolak type epoxy resin, bisphenol type epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin and the like.

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

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

Examples of the compound having an alkoxyalkylated amino group include, for example, (poly) methylolated melamine, (poly) methylolated glycoluril, (poly) methylolated benzoguanamine, (poly) methylolated urea, and the like in one molecule. Examples thereof include a nitrogen-containing compound having an active methylol group in which 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 of a plurality of substituted compounds, or may contain an oligomer component partially self-condensed.

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

The compounds represented by the above formulas (11-1) to (11-12) can be synthesized with reference to the following documents.
Compound represented by formula (11-1):
Guo, Qun-Sheng; Lu, Young-Na; Liu, Bing; Xiao, Jian; Li, Jin-Shan Journal of Organometallic 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):
Japanese Patent Application Laid-Open No. 5-238990 Compound represented by formula (11-5):
Bacon, R. et al. G. R. Bankhead, R.M. 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, p4949-4598

Among these cross-linking agents, a methoxymethyl group-containing phenol compound, a compound having an alkoxyalkylated amino group, and a random copolymer of acenaphthylene and hydroxymethylacenaftylene are preferable, and an alkoxyalkylated amino group is used. The compound having is more preferable, and 1,3,4,6-tetra (methoxymethyl) glycoluryl is further preferable.

When the resist underlayer film forming composition contains a cross-linking agent, the lower limit of the content of the cross-linking agent is preferably 0.1 part by mass and 0.5 part by mass with respect to 100 parts by mass of the [A] polymer. Parts are more preferable, 1 part by mass is further preferable, and 3 parts by mass is particularly preferable. The upper limit of the content is preferably 100 parts by mass, more preferably 50 parts by mass, further preferably 30 parts by mass, and particularly preferably 20 parts by mass. By setting the content of the cross-linking agent in the above range, the cross-linking reaction of the [A] polymer can be more effectively caused.

[Surfactant]
The composition for forming a resist underlayer film can improve the coatability by containing a surfactant, and as a result, the uniformity of the coated surface of the formed film is improved and the occurrence of coating spots is suppressed. can do. The surfactant may be used alone or in combination of two or more.

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, and polyethylene. Examples thereof include nonionic surfactants such as glycol distearate. As commercially available products, KP341 (Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, No. 95 (above, Kyoeisha Oil and Fat Chemical Industry), Ftop EF101, EF204, EF303, EF352 (above, Tochem Products), Megafuck F171, F172, F173 (above, DIC), Florard FC430 , FC431, FC135, FC93 (Sumitomo 3M Ltd.), Asahi Guard AG710, Surflon S382, SC101, SC102, SC103, SC104, SC105, SC106 (Asahi Glass Co., Ltd.), etc. Be done.

When the resist underlayer film forming composition contains a surfactant, the lower limit of the content of the surfactant is preferably 0.01 part by mass with respect to 100 parts by mass of the polymer [A], and 0. 05 parts by mass is more preferable, and 0.1 parts by mass is further preferable. As the upper limit of the content, 10 parts by mass is preferable, 5 parts by mass is more preferable, and 1 part by mass is further preferable. By setting the content of the surfactant in the above range, the coatability of the resist underlayer film forming composition can be further improved.

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

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

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

<Method of preparing composition for forming resist underlayer film>
The resist underlayer film forming composition was preferably obtained by mixing [A] polymer, [B] solvent, and if necessary, [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 or the like. 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.

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

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

[Resist underlayer film forming process]
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 carried out 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 silicon wafers and wafers coated with aluminum. Further, the method of applying the composition for forming the resist underlayer film to the substrate or the like is not particularly limited, and for example, it can be carried out by an appropriate method such as rotary coating, casting coating, roll coating and the like.

The heating of the coating film is usually performed in the atmosphere. As the lower limit of the heating temperature, 150 ° C. is preferable, 180 ° C. is more preferable, and 200 ° C. is further preferable. The upper limit of the heating temperature is preferably 500 ° C., more preferably 380 ° C., and even more preferably 300 ° C. If the heating temperature is less than 150 ° C., oxidative cross-linking may not proceed sufficiently and the properties required for the resist underlayer film may not be exhibited. The lower limit of the heating time is preferably 15 seconds, more preferably 30 seconds, and even more preferably 45 seconds. 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. If the oxygen concentration during heating is low, the oxidative cross-linking of the resist underlayer film may not proceed sufficiently, and the properties required for the resist underlayer film may not be exhibited.

Before heating the coating film at a temperature of 150 ° C. or higher and 500 ° C. or lower, preheating may be performed at a temperature of 60 ° C. or higher and 250 ° C. or lower. As the lower limit of the heating time in the preheating, 10 seconds is preferable, and 30 seconds is more preferable. The upper limit of the heating time is preferably 300 seconds, more preferably 180 seconds. By performing this preheating, the solvent is vaporized in advance to make the film dense, so that the dehydrogenation reaction can proceed efficiently.

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

The lower limit of the average thickness of the resist underlayer film to be formed is preferably 0.05 μm, more preferably 0.1 μm, and even more preferably 0.5 μm. As the upper limit of the average thickness, 5 μm is preferable, 3 μm is more preferable, and 2 μm is further preferable.

After the resist underlayer film forming step, if necessary, a step of forming an intermediate layer (intermediate film) on the surface side of the resist underlayer film opposite to the substrate may be further provided. This intermediate layer is a layer to which the above-mentioned functions are added in order to further supplement the functions of the resist underlayer film and / or the resist film in the formation of the resist pattern, or to give the functions that they do not have. .. 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 above-mentioned organic compound include commercially available products such as "DUV-42", "DUV-44", "ARC-28", and "ARC-29" (above, Brewer Science); "AR-3", "AR". -19 ”(above, Roam and Haas) and the like. Examples of the commercially available inorganic oxide include "NFC SOG01", "NFC SOG04", and "NFC SOG080" (above, JSR Corporation). Further, polysiloxane, titanium oxide, alumina oxide, tungsten oxide and the like formed by the CVD method can be used.

The method for forming the intermediate layer is not particularly limited, but for example, a coating method, a CVD method, or the like can be used. Among these, the coating method is preferable. When the coating method is used, the intermediate layer can be continuously formed after the resist underlayer film is formed. The average thickness of the intermediate layer is appropriately selected according to the function required of the intermediate layer, but the lower limit of the average thickness of the intermediate layer is preferably 10 nm, more preferably 20 nm. The upper limit of the average thickness is preferably 3,000 nm, more preferably 300 nm.

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

In the method using the resist composition, specifically, the resist composition is applied so that the obtained resist film has a predetermined thickness, and then the resist is volatilized by prebaking to volatilize the solvent in the coating film. Form a film.

Examples of the resist composition include a positive or negative chemically amplified resist composition containing a radiation-sensitive acid generator, a positive resist composition composed of an alkali-soluble resin and a quinonediazide-based photosensitive agent, and an alkali-soluble resin. Examples thereof include a negative resist composition composed of a cross-linking agent and a cross-linking agent.

The lower limit of the solid content concentration of the resist composition is preferably 0.3% by mass, more preferably 1% by mass. The upper limit of the solid content concentration is preferably 50% by mass, more preferably 30% by mass. Further, the resist composition is generally filtered through, for example, a filter having a pore size of about 0.2 μm to be used 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 prebake temperature is appropriately adjusted according to the type of resist composition used and the like, but the lower limit of the temperature is preferably 30 ° C., more preferably 50 ° C. The upper limit of the temperature is preferably 200 ° C., more preferably 150 ° C. As the lower limit of the prebaking time, 10 seconds is preferable, and 30 seconds is more preferable. The upper limit of the time is preferably 600 seconds, more preferably 300 seconds.

Next, the resist film formed above is exposed by selective irradiation. The radiation used for exposure includes electromagnetic waves such as visible light, ultraviolet rays, far ultraviolet rays, X-rays, and γ-rays; electron beams, molecular beams, etc., depending on the type of radiation-sensitive acid generator used in the resist composition. Appropriately selected from particle beams such as ion beams. Among these, deep ultraviolet rays are preferable, 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 beam (Radiation 134 nm) and extreme ultraviolet (UVV such as wavelength 13.5 nm) are more preferable, and KrF excimer laser light, ArF excimer laser light and EUV are further preferable.

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

Next, the exposed resist film is developed with a developing solution to form a resist pattern. This development may be alkaline development or organic solvent development. As the developing solution, in the case of alkaline 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] An alkaline aqueous solution such as -5-nonen can be mentioned. 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. Further, in the case of organic solvent development, examples of the developing solution 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 above developer.

As a method for performing the present resist pattern forming step, in addition to the method using the above-mentioned resist composition, a method using a nanoimprint method, a method using a self-assembling composition, and the like can also be used.

[Substrate pattern forming process]
In this step, a pattern is formed on the substrate by a plurality of etchings using the resist pattern as a mask. If the intermediate layer is not provided, the resist underlayer film and the substrate are sequentially etched, and if the intermediate layer is provided, the intermediate layer, the resist underlayer film, and the substrate are sequentially etched. Examples of this 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 above-mentioned resist underlayer film forming composition, it is excellent in solvent resistance, etching resistance, heat resistance and embedding property.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. The measurement method of various physical property values is shown below.

[Mw and Mn]
[A] For Mw and Mn of the polymer, a GPC column (two "G2000HXL" and one "G3000HXL") manufactured by Toso Co., Ltd. was used, the flow rate was 1.0 mL / min, the elution solvent was tetrahydrofuran, and the column temperature was 40. It was measured by a gel permeation chromatograph (detector: differential refractometer) using monodisperse polystyrene as a standard under analytical conditions of ° C.

[Solid content concentration]
By firing 0.5 g of the resist underlayer film forming composition at 250 ° C. for 30 minutes, the mass of the solid content with respect 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 (% by mass) was calculated.

[Average thickness of film]
The average thickness of the membrane 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, under nitrogen, 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 was charged. Next, 60 g of propylene glycol monomethyl ether acetate (PGMEA) was added and dissolved, 0.220 g (1.28 mmol) of p-toluenesulfonic acid monohydrate was added, and the mixture was stirred at 95 ° C. for 6 hours. Polymerized. Then, the polymerization reaction solution is put into a large amount of methanol / water (70/30 (mass ratio)) mixed solution, and the precipitate is filtered to obtain a polymer represented by the following formula (a-1). rice field. The Mw of the obtained polymer (a-1) was 4,216.

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

[Example 3]
4,4'-(α-methylbenzylidene) bisphenol 34.5 g (118.9 mmol), 2.80 g (29.7 mmol) of phenol and 3.49 g of paraformaldehyde in Example 1 were added to 4,4'-(α-methyl). Benzyllidene) Bisphenol 28.7 g (99.0 mmol), bisphenol fluorene 8.67 g (24.7 mmol) and paraformaldehyde 3.28 g were changed to the same reaction scheme as in Example 1 according to the following formula (a-3). The polymer represented by is synthesized. The Mw of the obtained polymer (a-3) was 4,030.

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

[Example 5]
3,4'-(α-methylbenzylidene) bisphenol 34.5 g (118.9 mmol), 2.80 g (29.7 mmol) of phenol and 3.49 g of paraformaldehyde in Example 1 were added to 4,4'-{1-[ To 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 modification. The Mw of the obtained polymer (a-5) was 3,602.

[Example 6]
4,4'-(α-methylbenzylidene) bisphenol 34.5 g (118.9 mmol), 2.80 g (29.7 mmol) of phenol and 3.49 g of paraformaldehyde in Example 1 were added to 4,4'-(α-methyl). Same as in Example 1 except that it was changed to 17.5 g (60.4 mmol) of bisphenol) bisphenol, 8.78 g (40.2 mmol) of 1-hydroxypyrene, 9.47 g (100.6 mmol) of phenol, and 4.76 g of paraformaldehyde. The following polymer (a-6) was synthesized by the reaction scheme of. The Mw of the obtained polymer (a-6) was 4,895.

[Example 7]
4,4'-(α-methylbenzylidene) bisphenol 34.5 g (118.9 mmol), 2.80 g (29.7 mmol) of phenol and 3.49 g of paraformaldehyde in Example 1 were added to 4,4'-(α-methyl). Bendilidene) 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) A polymer represented by the following formula (a-7) was synthesized by the same reaction scheme as in Example 1 except for the above. The Mw of the obtained polymer (a-7) was 3,363.

[Example 8]
3,4'-(α-methylbenzylidene) bisphenol 34.5 g (118.9 mmol), 2.80 g (29.7 mmol) of phenol and 3.49 g of paraformaldehyde in Example 1 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. The Mw of the obtained polymer (a-8) was 3,125.

[Example 9]
Bis (4-hydroxyphenyl) diphenylmethane 16 containing 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 in Example 1. Examples except changing to 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). A polymer represented by the following formula (a-9) was synthesized by the same reaction scheme as in 1. The Mw of the obtained polymer (a-9) was 2,885.

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

[Example 11]
In a three-necked flask equipped with a thermometer, condenser and mechanical stirrer, 13.3 g (45.9 mmol) of 4,4'-(α-methylbenzylidene) bisphenol and 6.61 g (45.9 mmol) of 1-naphthol under nitrogen. ) And 1-formylpyrene (20.8 g (90.1 mmol)) were charged. Next, 60 g of propylene glycol monomethyl ether acetate (PGMEA) was added and dissolved, then 4.40 g (23.1 mmol) of p-toluenesulfonic acid monohydrate was added, and the mixture was stirred at 130 ° C. for 8 hours for polymerization. did. Then, 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). rice field. The Mw of the obtained polymer (a-11) was 1,445.

[Example 12]
13.3 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 in Example 11 were added. 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-naphtholaldehyde 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). The Mw of the obtained polymer (a-12) was 2,202.

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

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

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

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

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

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

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

[Example 18]
20 g of the polymer (a-1), 22.2 g (161 mmol) of potassium carbonate and 19.1 g (161 mmol) of propargyl bromide in Example 13 were added to 20 g of the 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 that the amount was changed to 18.7 g (157 mmol) of propargyl bromide. The Mw of the obtained polymer (A-6) was 5,801.

[Example 19]
20 g of the polymer (a-1), 22.2 g (161 mmol) of potassium carbonate and 19.1 g (161 mmol) of propargyl bromide in Example 13 were added to 20 g of the 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 the amount was changed to 16.2 g (136 mmol) of propargyl bromide. The Mw of the obtained polymer (A-7) was 3,820.

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

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

[Example 22]
20 g of the polymer (a-1), 22.2 g (161 mmol) of potassium carbonate and 19.1 g (161 mmol) of propargyl bromide in Example 13 were added to 20 g of the polymer (a-10), 14.8 g (107 mmol) of potassium carbonate, and the like. 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. The Mw of the obtained polymer (A-10) was 2,967.

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

[Example 24]
20 g of the polymer (a-1), 22.2 g (161 mmol) of potassium carbonate and 19.1 g (161 mmol) of propargyl bromide in Example 13 were added to 20 g of the polymer (a-12) and 12.6 g (90.9 mmol) of potassium carbonate. ) And propargyl bromide (10.8 g (90.9 mmol)), and the same reaction scheme as in Example 13 was used to synthesize a polymer represented by the following formula (A-12). The 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, the weight represented by the following formula (A-13) was used. The coalescence was synthesized. The Mw of the obtained polymer (A-13) was 3,995.

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

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

[Synthesis 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 in Example 1 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. The Mw of the obtained polymer (c-1) was 2,420.

[Synthesis Example 2]
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 in Example 1 were added to 37.9 g (108 mmol) of bisphenol fluorene. A polymer represented by the following formula (c-2) was synthesized by the same reaction scheme as in Example 1 except that it was changed to 2.86 g of paraformaldehyde. The Mw of the obtained polymer (c-2) was 4,562.

<Preparation of composition for forming a resist underlayer film>
The components other than the [A] polymer used for preparing 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-butane sulfonate (compound represented by the following formula (C-1))

([D] Crosslinking agent)
D-1: 1,3,4,6-tetramethoxymethylglycoluryl (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 27-56 and 142-145 and Comparative Examples 1 and 2]
Each resist underlayer film forming composition was prepared by the same procedure as in Example 26 except that each component of the type and amount shown in Table 1 was 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 resist underlayer film forming compositions prepared above was applied onto a silicon wafer substrate by a spin coating method. Then, it was heated (baked) at 220 ° C. for 60 seconds in an air atmosphere to form a resist underlayer film having a thickness of 200 nm, and a substrate with a resist underlayer film having a resist underlayer film formed on the substrate was obtained. Examples 57 to 75 and Comparative Examples 3 and 4). Further, in Examples 76 to 106 and 146 to 149 and Comparative Examples 5 and 6, substrates with a resist underlayer film were obtained by heating (baking) at 400 ° C. for 90 seconds.

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

<Evaluation>
Various evaluations were carried out on the obtained composition for forming a resist underlayer film, a substrate with a resist underlayer film, and a stepped substrate with a resist underlayer film by the following procedure. 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, and the average film thickness after immersion is X, and the absolute value of the numerical value obtained by (X-X0) x 100 / X0 is calculated to calculate the film. 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 the film thickness change rate is 1% or more and less than 5%, and "C" when the film thickness change rate is 5% or more. It was evaluated as (defective).

[Etching resistance]
With respect to the obtained substrate with a resist underlayer film, CF ₄ / Ar = 110/440 sccm, PRESS. Treatment was performed under the conditions of = 30 MT, HF RF = 500 W, LF RF = 3000 W, DCS = -150 V, RDC = 50%, 30 sec, and (nm / min) was calculated from the average film thickness before and after the treatment, as compared with Comparative Example 4. The ratio was calculated. The etching resistance is 1.0 or more, "A" (extremely good) when the above ratio is 0.95 or more and less than 0.98, and "B" (good) when the above ratio is 0.98 or more and less than 1.00. In the case of, it was evaluated as "C" (defective).

[Heat-resistant]
The above-prepared composition for forming a resist underlayer film was spin-coated on a silicon wafer having a diameter of 8 inches to form a resist underlayer film, and a substrate with a resist underlayer film was obtained. The powder was recovered from the substrate with the resist underlayer film, the powder was placed in a container, and the mass before heating was measured. Next, the resist underlayer film was heated at 400 ° C. for 150 seconds. After recovering the powder from the substrate, it is heated to 400 ° C. at a heating rate of 10 ° C./min under a nitrogen atmosphere using a TG-DTA device (“TG-DTA2000SR” manufactured by NETZSCH) to 400 ° C. The mass of the powder in was measured. Then, the 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 smaller the mass reduction rate of the powder as a sample, the less the sublimation product and the decomposition product of the resist underlayer film generated when the resist underlayer film is heated, and the better the heat resistance. That is, the smaller the mass reduction rate, the higher the heat resistance. The heat resistance is "A" (extremely good) when the mass reduction value is less than 5%, "B" (good) when the mass reduction value is 5% or more and less than 10%, and "C" (good) when the mass reduction value is 10% or more. Defective).

[Embedability]
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 embedding property (void) was evaluated. Those without voids were evaluated as "A" (good), and those with voids were evaluated as "B" (poor).

[Edge rinse property]
[Examples 107-137 and 150-153 and Comparative Examples 7 and 8]
Propylene glycol monomethyl ether acetate (PGMEA) was discharged from a nozzle to the edge portion of the substrate in a state where the substrate coated with the obtained resist underlayer film forming composition was rotated at 1000 rpm. Then, the substrate was rotated at 1000 rpm for 10 seconds. With respect to the above-mentioned obtained substrate, the residual film at the edge portion of the substrate was evaluated. Those without residual film were evaluated as "A" (good), and those with residual film were evaluated as "B" (poor).

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

According to the resist underlayer film forming composition of the present invention, PGMEA or the like can be used as a solvent, and a resist underlayer film having excellent edge rinse property, 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 property, 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 formed excellent resist underlayer film. Therefore, these can be suitably used for manufacturing semiconductor devices and the like, which are expected to be further miniaturized in the future.

Claims (7)

Contains a polymer for forming a resist underlayer film and an organic solvent,
The polymer for forming the resist underlayer film is
The first repeating unit represented by the following formula (1) and whose main chain is formed of two molecules,
A composition for forming a resist underlayer film, which is a repeating unit different from the first repeating unit and has a second repeating unit represented by the following formula (2) .

(In the formula (1), Ar ¹ , Ar ² and Ar ³ are independently substituted or unsubstituted arelane diyl groups having 6 to 30 carbon atoms. R ¹ is substituted or unsubstituted carbon number 1 It is a divalent hydrocarbon group of ~ 30. N is 0 or 1. R ² is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms or a substituted or unsubstituted alkyl group having 6 to 30 carbon atoms. It is an aryl group. R ³ is a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms ^{. R 4} is a hydrogen atom or 1 of substituted or unsubstituted carbon atoms 1 to 30. It is a valent hydrocarbon group.)

In the formula (2), Ar ⁴ is a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms, and the divalent aromatic hydrocarbon group is a naphthalenediyl group or anthracenediyl. A group, a phenylenediyl group, a pyrenedyl group, a chrysendyl group, a tetrasendyl group, a perylenediyl group, a pentasendiyl group, or a fluorinatedyl group. R ⁵ is a hydrogen atom or one of 1 to 30 having a substituted or unsubstituted carbon number. It is a valent hydrocarbon group.) The resin underlayer film forming polymer is composed of 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. The composition for forming a resist underlayer film according to claim 1, which has at least one selected. The composition for forming a resist underlayer film according to claim 2 , wherein the monovalent group containing the carbon-carbon triple bond is a propargyloxy group. The composition for forming a resist underlayer film according to any one of claims 1 to 3 , wherein the polymer for forming a resist underlayer film has a weight average molecular weight of 1,000 or more and 10,000 or less. A resist underlayer film formed from the resist underlayer film forming composition according to any one of claims 1 to 4. The process of forming a resist underlayer film on one surface side of the substrate and
The step of forming a resist pattern on the surface side of the resist underlayer film opposite to the substrate, and
It is provided with a step of forming a pattern on a substrate by etching a plurality of times using the above resist pattern as a mask.
A method for producing a patterned substrate, wherein the resist underlayer film is formed of the resist underlayer film forming composition according to any one of claims 1 to 4. The composition for forming a resist underlayer film according to any one of claims 1 to 4 , further comprising a step of reacting the compound represented by the following formula (3) with the compound represented by the following formula (4). How to make things.

(In the formula (3), Ar ^{1 'and} Ar ^3' are each independently, .Ar ² is a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted carbon atoms 6 It is an arylandyl group of 30. R ¹ is a divalent hydrocarbon group having 1 to 30 carbon atoms. N is 0 or 1. R ² is a substituted or unsubstituted carbon number of 1 to 10 carbon atoms. It is an alkyl group or an 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 formula (4), R ⁴ is a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 30 carbon atoms. )