JP2017003959A - Resist underlay film material and pattern formation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist underlay film material that has excellent embedding properties, reduces outgassing, and has excellent dry etching resistance and heat resistance.SOLUTION: A resist underlay film material comprises an acrylonitrile polymer having a repeating unit comprising at least one fluorine atom, and one or both of a novolac resin represented by a specific formula and a bisnaphthol derivative represented by a specific formula.SELECTED DRAWING: None

Description

  The present invention relates to a resist underlayer film material and a pattern forming method used for fine processing in a manufacturing process of a semiconductor device or the like.

  In recent years, in order to form wiring with high density by three-dimensional gates such as ultra-fine and high-density Fin-FET (fin type field effect transistor) and dual damascene that simultaneously forms a trench and a via of copper wiring, Etching is repeated a plurality of times (LELE: Litho-Etch-Litho-Etch) double patterning has been performed, and a material capable of embedding a high-aspect and high-density step is required. By embedding the step, the film surface is flattened, focus leveling in lithography is small, and patterning can be performed with a sufficient margin even when the focus margin is narrow.

  As a method for flattening the stepped substrate, a method using spin coating is generally used. An amorphous carbon film can be formed by CVD (Chemical Vapor Deposition) method, and the step can be embedded, but since the surface has irregularities, it is necessary to cut and planarize the film surface by CMP (Chemical Mechanical Polishing) method, There is a demerit that process cost is high. In addition, the amorphous carbon film formed by the CVD method has a problem that voids are generated at the bottom of the step at an extremely fine step having a pitch of 50 nm or less and cannot be embedded. Ultra fine steps with a pitch of 50 nm or less can be embedded by spin-coating a material containing a large amount of low molecular weight substances.

  By immersion lithography, the angle of light at the time of exposure incident on the resist and its lower layer becomes shallow, and the substrate reflection increases. In order to suppress substrate reflection, it is effective to use a multilayer anti-reflection film under the resist. A three-layer structure (trilayer) in which a hydrocarbon film with high carbon density (resist underlayer film) is formed on a substrate, a silicon-containing resist intermediate layer film thereon, and a resist upper layer film thereon is formed. Since the reflection of the substrate can be prevented by the two layers of the intermediate layer film, this application is spreading rapidly with the application of immersion lithography.

  As a function of the resist underlayer film, an embedding flattening characteristic by spin coating, a high dry etching resistance when the substrate is dry-etched, and an optimum optical characteristic for obtaining a high antireflection effect are required.

Moreover, high heat resistance may be required for the resist underlayer film. This is because when p-Si, SiN, SiON, TiN, ZrO ₂ , HfO ₂ or the like is formed as a hard mask layer on the resist underlayer film, the formation temperature of these films exceeds 300 ° C.

  As such a heat-resistant resist underlayer film material, a bisnaphthol compound and a novolac resin described in Patent Document 1, a bisnaphthol fluorene and a novolak resin described in Patent Document 2, and a naphtholphthalein described in Patent Document 3 And naphthofluorescein novolak resin described in Patent Document 4.

  Further, outgas generated during baking at the time of forming the resist underlayer film is a problem. The outgas component adheres to the top plate of the hot plate and becomes a defect when it falls on the wafer. In order to improve the embedding characteristics of the stepped substrate, it is effective to add a monomer component (low molecular weight component) as a resist underlayer film material. However, if the amount of the monomer component added is increased, the amount of outgas in the high-temperature baking is increased. Will increase. That is, there is a trade-off between improving the embedding characteristics and reducing the outgas, and a resist underlayer film material that can overcome this trade-off is demanded.

Japanese Patent No. 4659678 Japanese Patent No. 5336306 Japanese Patent Laying-Open No. 2015-18221 Japanese Patent Laying-Open No. 2015-18223

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a resist underlayer film material that has good embedding characteristics, generates less outgas, and has excellent dry etching resistance and heat resistance.

（式中、Ｒ^１、Ｒ^２は水素原子、フッ素原子、メチル基、又はトリフルオロメチル基である。Ｒ^３は単結合、フェニレン基、又は炭素数１〜１１のアルキレン基である。Ｒ^４はフッ素原子であるか、少なくとも１個以上のフッ素原子を有する炭素数１〜１０の直鎖状、分岐状、若しくは環状のアルキル基、炭素数２〜１０のアルケニル基、又は炭素数６〜１０のアリール基であり、これらがヒドロキシ基、アルコキシ基、アシル基、スルホキシド基、スルホン基、又はスルホンアミド基を有していてもよい。Ｒ^５、Ｒ^６、Ｒ^１２、Ｒ^１３は水素原子、酸不安定基、及びグリシジル基のいずれか、又は炭素数１〜１０の直鎖状、分岐状、若しくは環状のアルキル基、アシル基、若しくはアルコキシカルボニル基である。Ｒ^７、Ｒ^８は水素原子、ヒドロキシ基、及び炭素数１〜４のアルコキシ基のいずれか、又はヒドロキシ基、アルコキシ基、アシロキシ基、エーテル基、若しくはスルフィド基を有していてもよい炭素数１〜１０の直鎖状、分岐状、若しくは環状のアルキル基、炭素数２〜１０のアルケニル基、若しくは炭素数６〜１０のアリール基である。Ｒ^１４、Ｒ^１５はＲ^７、Ｒ^８と同様の基又はハロゲン原子である。Ｒ^９、Ｒ^１０、Ｒ^１６、Ｒ^１７は水素原子であるか、あるいはＲ^９とＲ^１０、Ｒ^１６とＲ^１７が結合して形成されるエーテル結合である。Ｒ^１１は水素原子、又はヒドロキシ基、アルコキシ基、アシロキシ基、エーテル基、スルフィド基、クロロ基、若しくはニトロ基を有していてもよい炭素数１〜６のアルキル基、炭素数２〜１０のアルケニル基、若しくは炭素数６〜１０のアリール基である。Ｘ_１はフェニレン基、エーテル基、又はエステル基である。Ｘ_２、Ｘ_３は単結合であるか、あるいはヒドロキシ基、カルボキシル基、エーテル基、若しくはラクトン環を有していてもよい炭素数１〜３８の直鎖状、分岐状、又は環状の２価炭化水素基である。Ｘ_２が２価炭化水素基の場合、Ｒ^９及びＲ^１０はＸ_２中の炭素原子と結合して形成されるエーテル結合であってもよく、Ｘ_３が２価炭化水素基の場合、Ｒ^１６及びＲ^１７はＸ_３中の炭素原子と結合して形成されるエーテル結合であってもよい。ａ及びｂは、０＜ａ≦１．０、０≦ｂ＜１．０であるが、Ｒ^１がフッ素原子を有さない場合は０＜ａ＜１．０、０＜ｂ＜１．０である。ｃは１≦ｃ≦６の整数であり、ｃが２以上の場合は、ｃの数だけＲ^４でＲ^３の水素原子が置換される。ｇ、ｈ、ｉ、ｊ、ｋ、ｌ、ｍ、及びｎは１又は２である。） In order to solve the above problems, in the present invention, an acrylonitrile polymer having a repeating unit containing at least one fluorine atom represented by the following general formula (1), and a repeating unit represented by the following general formula (2): There is provided a resist underlayer film material containing either or both of a novolak resin having a bisnaphthol derivative represented by the following general formula (3).

(In the formula, R ¹ and R ² are a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R ³ is a single bond, a phenylene group, or an alkylene group having 1 to 11 carbon atoms. R ⁴ Is a fluorine atom, or a C1-C10 linear, branched or cyclic alkyl group having at least one fluorine atom, a C2-C10 alkenyl group, or a C6-C10 Which may have a hydroxy group, an alkoxy group, an acyl group, a sulfoxide group, a sulfone group, or a sulfonamide group, wherein R ⁵ , R ⁶ , R ¹² , and R ¹³ are a hydrogen atom, acid labile groups, and one of a glycidyl group, or a straight, branched, or cyclic alkyl group, an acyl group, or alkoxycarbonyl .R ^7, R ⁸ is a carbonyl group Any one of an elementary atom, a hydroxy group, and an alkoxy group having 1 to 4 carbon atoms, or a straight chain having 1 to 10 carbon atoms which may have a hydroxy group, an alkoxy group, an acyloxy group, an ether group, or a sulfide group A branched, or cyclic alkyl group, an alkenyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms R ¹⁴ and R ¹⁵ are the same groups or halogen atoms as R ⁷ and R ⁸ R ⁹ , R ¹⁰ , R ¹⁶ and R ¹⁷ are hydrogen atoms, or are ether bonds formed by combining R ⁹ and R ¹⁰ , R ¹⁶ and R ^17, and R ¹¹ is a hydrogen atom. Or an alkyl group having 1 to 6 carbon atoms which may have a hydroxy group, an alkoxy group, an acyloxy group, an ether group, a sulfide group, a chloro group or a nitro group; Kenyir group, or an aryl group having a carbon number of 6 to 10 .X ₁ is a phenylene group, an ether group, or an ester group .X _2, or X ₃ is a single bond, or a hydroxy group, a carboxyl group, an ether Or a straight-chain, branched or cyclic divalent hydrocarbon group having 1 to 38 carbon atoms which may have a lactone ring, and when X ₂ is a divalent hydrocarbon group, R ⁹ and R ¹⁰ may be an ether bond formed by bonding to a carbon atom in X ₂ , and when X ₃ is a divalent hydrocarbon group, R ¹⁶ and R ¹⁷ are bonded to a carbon atom in X _3. A and b are 0 <a ≦ 1.0 and 0 ≦ b <1.0, but when R ¹ does not have a fluorine atom, 0 <a <1.0, 0 <b <1.0. c is an integer of 1 ≦ c ≦ 6, when c is 2 or more, the number of c hydrogen atoms in R ⁴ R ³ are substituted. g, h, i, j, k, l, m, and n are 1 or 2. )

  Such a resist underlayer film material has good embedding characteristics, little outgassing, and excellent dry etching resistance and heat resistance.

  In this case, the novolak resin having the repeating unit represented by the general formula (2) is a condensate of an aldehyde derivative having no fluorine atom and a substituted or unsubstituted bisnaphthol derivative having no fluorine atom. Is preferred.

  As the novolak resin used for the resist underlayer film material of the present invention, such a condensate can be suitably used.

  At this time, the resist underlayer film material includes an acrylonitrile polymer having a repeating unit represented by the general formula (1), a novolac resin having a repeating unit represented by the general formula (2), and the general formula (3). It is preferable that it contains the bisnaphthol derivative shown by this.

  Thus, all three types of acrylonitrile polymer having a repeating unit represented by the general formula (1), a novolak resin having a repeating unit represented by the general formula (2), and a bisnaphthol derivative represented by the general formula (3) are used. By including, the improvement of the embedding characteristic and the reduction of outgas can be achieved in a more balanced manner.

  Further, at this time, the resist underlayer film material has a novolak resin having a repeating unit represented by the general formula (2) with respect to 1 part by mass of the acrylonitrile polymer having a repeating unit represented by the general formula (1). It is preferable to contain a total of 5 to 100 parts by mass of the bisnaphthol derivative represented by the general formula (3).

  With such a ratio, improvement of the embedding characteristic and reduction of outgas can be achieved in a particularly balanced manner.

  At this time, it is preferable that the resist underlayer film material further contains an organic solvent.

  By doing in this way, the density | concentration and viscosity of a resist underlayer film material can be adjusted, and compatibility can be improved.

  At this time, it is preferable that the resist underlayer film material further contains an acid generator and / or a crosslinking agent.

  By doing in this way, the crosslinking hardening reaction of a resist underlayer film material can be promoted.

  The present invention also provides a method for forming a pattern on a substrate by lithography, wherein a resist underlayer film is formed on the substrate to be processed using the resist underlayer film material, and a silicon-containing intermediate layer film material is formed on the resist underlayer film. A silicon-containing intermediate layer film is formed using, a resist upper layer film is formed on the silicon-containing intermediate layer film using a resist upper layer film material, and a pattern circuit region of the resist upper layer film is exposed and developed. A resist pattern is formed on the resist upper layer film, the resist upper layer film on which the resist pattern is formed is used as a mask, the pattern is transferred to the silicon-containing intermediate layer film by etching, and the silicon-containing intermediate layer film on which the pattern is transferred A pattern is transferred to the resist underlayer film by etching using the resist as a mask, and the resist underlayer film to which the pattern is transferred is used as a mask to transfer the pattern. Providing a pattern forming method for forming a pattern on a substrate by etching.

  The present invention also provides a method of forming a pattern on a substrate by lithography, wherein a resist underlayer film is formed on the substrate to be processed using the resist underlayer film material, and a silicon oxide film, silicon Forming an inorganic hard mask interlayer film selected from a nitride film, a silicon oxynitride film, a silicon carbide film, a polysilicon film, a titanium nitride film, a titanium oxide film, a titanium carbide film, a zirconium oxide film, or a hafnium oxide film, A resist upper layer film is formed on the inorganic hard mask intermediate layer film using a resist upper layer film material, and a pattern circuit region of the resist upper layer film is exposed, and then developed to form a resist pattern on the resist upper layer film. Using the resist upper layer film on which the resist pattern is formed as a mask, the pattern is transferred to the inorganic hard mask intermediate layer film by etching, and the pattern is transferred. A pattern is transferred to the resist underlayer film by etching using the inorganic hard mask intermediate layer film to which the pattern is transferred as a mask, and further etched to the substrate to be processed using the resist underlayer film to which the pattern is transferred as a mask. A pattern forming method is provided.

  The present invention also provides a method of forming a pattern on a substrate by lithography, wherein a resist underlayer film is formed on the substrate to be processed using the resist underlayer film material, and a silicon oxide film, silicon Forming an inorganic hard mask interlayer film selected from a nitride film, a silicon oxynitride film, a silicon carbide film, a polysilicon film, a titanium nitride film, a titanium oxide film, a titanium carbide film, a zirconium oxide film, or a hafnium oxide film, An organic antireflection film is formed on the inorganic hard mask intermediate film, a resist upper film is formed on the organic antireflection film by using a resist upper film material to form a four-layer resist film, and the resist upper film pattern circuit After exposing the region, development is performed to form a resist pattern on the resist upper layer film, and the resist upper layer film on which the resist pattern is formed is used as a mask. A pattern is transferred by etching to the organic antireflection film and the inorganic hard mask intermediate layer film, the pattern is transferred by etching to the resist underlayer film using the inorganic hard mask intermediate layer film to which the pattern is transferred as a mask, Provided is a pattern forming method for forming a pattern by etching on the substrate to be processed using a resist underlayer film to which the pattern is transferred as a mask.

  The present invention also provides a method of forming a pattern on a substrate by lithography, wherein a resist underlayer film is formed on the substrate to be processed using the resist underlayer film material, and a silicon oxide film, silicon Forming an inorganic hard mask interlayer film selected from a nitride film, a silicon oxynitride film, a silicon carbide film, a polysilicon film, a titanium nitride film, a titanium oxide film, a titanium carbide film, a zirconium oxide film, or a hafnium oxide film, A hydrocarbon film is formed by spin coating using a hydrocarbon film material on the inorganic hard mask interlayer film, and a silicon-containing interlayer film is formed on the hydrocarbon film using a silicon-containing interlayer film material, A resist upper layer film is formed on the silicon-containing intermediate layer film using a resist upper layer film material to form a five-layer resist film. After exposing the pattern circuit region of the resist upper layer film, development is performed. A silicon-containing intermediate layer film in which a resist pattern is formed on the resist upper layer film, the pattern is transferred to the silicon-containing intermediate layer film by etching using the resist upper layer film on which the resist pattern is formed as a mask, and the pattern is transferred A pattern is transferred to the hydrocarbon film by etching using the mask as a mask, and the pattern is transferred to the inorganic hard mask intermediate layer film by using the hydrocarbon film to which the pattern is transferred as an etching mask. Using the inorganic hard mask intermediate layer film as a mask, a pattern is transferred to the resist underlayer film by etching. Further, using the resist underlayer film to which the pattern is transferred as a mask, the pattern is etched onto the substrate to be processed. A pattern forming method is provided.

  By performing pattern formation using the resist underlayer film material of the present invention, which has good embedding characteristics, little outgassing, and excellent dry etching resistance and heat resistance, it can be used for fine processing in the manufacturing process of semiconductor devices and the like. Defects can be greatly reduced.

  At this time, the inorganic hard mask intermediate layer film is preferably formed by any one of a CVD method, an ALD method, and a sputtering method.

  Such a method is suitable for forming an inorganic hard mask intermediate layer film.

  Also, at this time, the resist underlayer film that is formed using a material that does not contain a silicon atom-containing polymer as the resist upper layer film material and that uses the silicon-containing intermediate layer film or the inorganic hard mask intermediate layer film as a mask. This etching is preferably performed using an etching gas containing oxygen gas or hydrogen gas.

  By doing so, the removal of the resist upper layer film and the etching of the resist lower layer film can be performed simultaneously.

  As described above, with the resist underlayer film material of the present invention, it is possible to form a resist underlayer film having good embedding characteristics, less outgas generation, and excellent dry etching resistance and heat resistance. Also, the film thickness uniformity of the resist underlayer film can be improved. In addition, the pattern forming method of the present invention using such a resist underlayer film material can sufficiently embed a substrate and suppress the generation of outgas. Defects during processing can be greatly reduced. Therefore, the resist underlayer film and pattern forming method of the present invention are particularly required to suppress the occurrence of outgassing at the time of baking of the resist underlayer film, which is a source of defects, as well as embedding a trench pattern having a thin co-pitch. It is suitable for manufacturing a three-dimensional device such as an FET.

It is a flowchart which shows an example of the pattern formation method of the 3 layer process of this invention using a silicon containing intermediate | middle layer film. It is a flowchart which shows an example of the pattern formation method of the three-layer process of this invention using an inorganic hard mask intermediate | middle layer film. It is a flowchart which shows an example of the pattern formation method of the 4 layer process of this invention. It is a flowchart which shows an example of the pattern formation method of the 5 layer process of this invention.

  As described above, there has been a demand for the development of a resist underlayer film material that has good embedding characteristics and generates less outgas. In order to improve the embedding characteristics, it is effective to add a monomer component to the resist underlayer film material. However, when a monomer component is added, the monomer component evaporates during baking to become outgas and adheres to the top plate of the hot plate. When the material attached to the top plate falls, it causes a defect, so that the performance of improving the embedding characteristic and the performance of preventing outgas have a trade-off relationship. The inventors of the present invention have made extensive studies in order to construct a resist underlayer film material having excellent embedding characteristics and generating less outgas, and there are many monomer components necessary for embedding on the stepped substrate side, and polymer components on the surface layer. It has been conceived that the structure of the resist underlayer film in which a large amount of is distributed is effective in improving both the embedding characteristics and suppressing the outgas generation.

  The present inventors have further studied, and an acrylonitrile polymer having a repeating unit containing at least one fluorine atom represented by the general formula (1) and a novolac resin having a repeating unit represented by the general formula (2). And if it is a resist underlayer film material blended with either or both of the bisnaphthol derivatives represented by the following general formula (3), the embedding characteristics are improved and the generation of outgas is suppressed even when a large amount of monomer components are contained. As a result, the present invention has been completed.

（式中、Ｒ^１、Ｒ^２は水素原子、フッ素原子、メチル基、又はトリフルオロメチル基である。Ｒ^３は単結合、フェニレン基、又は炭素数１〜１１のアルキレン基である。Ｒ^４はフッ素原子であるか、少なくとも１個以上のフッ素原子を有する炭素数１〜１０の直鎖状、分岐状、若しくは環状のアルキル基、炭素数２〜１０のアルケニル基、又は炭素数６〜１０のアリール基であり、これらがヒドロキシ基、アルコキシ基、アシル基、スルホキシド基、スルホン基、又はスルホンアミド基を有していてもよい。Ｒ^５、Ｒ^６、Ｒ^１２、Ｒ^１３は水素原子、酸不安定基、及びグリシジル基のいずれか、又は炭素数１〜１０の直鎖状、分岐状、若しくは環状のアルキル基、アシル基、若しくはアルコキシカルボニル基である。Ｒ^７、Ｒ^８は水素原子、ヒドロキシ基、及び炭素数１〜４のアルコキシ基のいずれか、又はヒドロキシ基、アルコキシ基、アシロキシ基、エーテル基、若しくはスルフィド基を有していてもよい炭素数１〜１０の直鎖状、分岐状、若しくは環状のアルキル基、炭素数２〜１０のアルケニル基、若しくは炭素数６〜１０のアリール基である。Ｒ^１４、Ｒ^１５はＲ^７、Ｒ^８と同様の基又はハロゲン原子である。Ｒ^９、Ｒ^１０、Ｒ^１６、Ｒ^１７は水素原子であるか、あるいはＲ^９とＲ^１０、Ｒ^１６とＲ^１７が結合して形成されるエーテル結合である。Ｒ^１１は水素原子、又はヒドロキシ基、アルコキシ基、アシロキシ基、エーテル基、スルフィド基、クロロ基、若しくはニトロ基を有していてもよい炭素数１〜６のアルキル基、炭素数２〜１０のアルケニル基、若しくは炭素数６〜１０のアリール基である。Ｘ_１はフェニレン基、エーテル基、又はエステル基である。Ｘ_２、Ｘ_３は単結合であるか、あるいはヒドロキシ基、カルボキシル基、エーテル基、若しくはラクトン環を有していてもよい炭素数１〜３８の直鎖状、分岐状、又は環状の２価炭化水素基である。Ｘ_２が２価炭化水素基の場合、Ｒ^９及びＲ^１０はＸ_２中の炭素原子と結合して形成されるエーテル結合であってもよく、Ｘ_３が２価炭化水素基の場合、Ｒ^１６及びＲ^１７はＸ_３中の炭素原子と結合して形成されるエーテル結合であってもよい。ａ及びｂは、０＜ａ≦１．０、０≦ｂ＜１．０であるが、Ｒ^１がフッ素原子を有さない場合は０＜ａ＜１．０、０＜ｂ＜１．０である。ｃは１≦ｃ≦６の整数であり、ｃが２以上の場合は、ｃの数だけＲ^４でＲ^３の水素原子が置換される。ｇ、ｈ、ｉ、ｊ、ｋ、ｌ、ｍ、及びｎは１又は２である。） That is, the present invention relates to an acrylonitrile polymer having a repeating unit containing at least one fluorine atom represented by the following general formula (1), a novolak resin having a repeating unit represented by the following general formula (2), and the following general formula It is a resist underlayer film material containing either or both of the bisnaphthol derivative represented by the formula (3).

(In the formula, R ¹ and R ² are a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R ³ is a single bond, a phenylene group, or an alkylene group having 1 to 11 carbon atoms. R ⁴ Is a fluorine atom, or a C1-C10 linear, branched or cyclic alkyl group having at least one fluorine atom, a C2-C10 alkenyl group, or a C6-C10 Which may have a hydroxy group, an alkoxy group, an acyl group, a sulfoxide group, a sulfone group, or a sulfonamide group, wherein R ⁵ , R ⁶ , R ¹² , and R ¹³ are a hydrogen atom, acid labile groups, and one of a glycidyl group, or a straight, branched, or cyclic alkyl group, an acyl group, or alkoxycarbonyl .R ^7, R ⁸ is a carbonyl group Any one of an elementary atom, a hydroxy group, and an alkoxy group having 1 to 4 carbon atoms, or a straight chain having 1 to 10 carbon atoms which may have a hydroxy group, an alkoxy group, an acyloxy group, an ether group, or a sulfide group A branched, or cyclic alkyl group, an alkenyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms R ¹⁴ and R ¹⁵ are the same groups or halogen atoms as R ⁷ and R ⁸ R ⁹ , R ¹⁰ , R ¹⁶ and R ¹⁷ are hydrogen atoms, or are ether bonds formed by combining R ⁹ and R ¹⁰ , R ¹⁶ and R ^17, and R ¹¹ is a hydrogen atom. Or an alkyl group having 1 to 6 carbon atoms which may have a hydroxy group, an alkoxy group, an acyloxy group, an ether group, a sulfide group, a chloro group or a nitro group; Kenyir group, or an aryl group having a carbon number of 6 to 10 .X ₁ is a phenylene group, an ether group, or an ester group .X _2, or X ₃ is a single bond, or a hydroxy group, a carboxyl group, an ether Or a straight-chain, branched or cyclic divalent hydrocarbon group having 1 to 38 carbon atoms which may have a lactone ring, and when X ₂ is a divalent hydrocarbon group, R ⁹ and R ¹⁰ may be an ether bond formed by bonding to a carbon atom in X ₂ , and when X ₃ is a divalent hydrocarbon group, R ¹⁶ and R ¹⁷ are bonded to a carbon atom in X _3. A and b are 0 <a ≦ 1.0 and 0 ≦ b <1.0, but when R ¹ does not have a fluorine atom, 0 <a <1.0, 0 <b <1.0. c is an integer of 1 ≦ c ≦ 6, when c is 2 or more, the number of c hydrogen atoms in R ⁴ R ³ are substituted. g, h, i, j, k, l, m, and n are 1 or 2. )

  Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

<Resist underlayer film material>
The resist underlayer film material of the present invention includes an acrylonitrile polymer having a repeating unit containing at least one fluorine atom represented by the general formula (1) and a novolac resin having a repeating unit represented by the general formula (2). And any one or both of the bisnaphthol derivatives represented by the following general formula (3). In such a resist underlayer film material, the film surface is covered with an acrylonitrile polymer having a repeating unit containing at least one fluorine atom represented by the general formula (1) in the spin coating. Owing to the presence of the layer containing fluorine atoms, generation of outgas can be suppressed even when a resist underlayer film material containing a monomer component for improving the embedding characteristics is baked at a high temperature.

  Further, when the silicon-containing intermediate layer film (SOG film) on the resist underlayer film is peeled off with a hydrofluoric acid aqueous solution, the TiN film or the BPSG (Boron Phosphorus Silicate Glass) film is formed with an alkaline stripping solution SC (Standard Clean) 1. In order to prevent damage to the resist underlayer film surface in the case of peeling, it is effective that a layer containing fluorine atoms is formed on the surface layer of the resist underlayer film. This is because permeation of the hydrofluoric acid aqueous solution or SC1 into the resist underlayer film can be prevented by the water repellency of fluorine.

  In addition to the silicon-containing intermediate layer film formed by spin coating, an inorganic film that combines an antireflection film such as a SiON film or a TiN film and a hard mask may be formed on the resist underlayer film. The SiON film has not only an excellent antireflection effect, but also has a feature of higher dry etching resistance than a silicon-containing intermediate layer film formed by spin coating. In addition, the TiN film has not only high dry etching resistance, but also has an advantage that it can be stripped with an alkaline stripping solution such as SC1. When these SiON films and TiN films are formed, a substrate temperature of 300 ° C. or higher is required. Therefore, a resist underlayer film having insufficient heat resistance even with good dry etching resistance or the like is made of such an inorganic film. It cannot be applied to the forming method. On the other hand, since the resist underlayer film formed using the resist underlayer film material of the present invention has sufficient heat resistance, it can be suitably used when forming an inorganic film that requires heating at 300 ° C. or higher as described above. Can do.

  For example, when the lower layer film solution is applied onto a stepped substrate on which a hole pattern is formed, a void exists at the bottom of the hole immediately after the application, and the hole is buried after high temperature baking. This indicates that the resin flows during baking, the resin is buried in the bottom of the hole, and the voids become voids that move toward the surface of the lower layer film and disappear.

  Usually, when the solution containing the resin is rotated at a low speed of 500 rpm or less and then the solvent is evaporated by baking, the film thickness becomes nonuniform. On the other hand, when spin coating is performed at a rotation of 700 rpm or more, the film thickness non-uniformity does not occur. The phenomenon that the film thickness becomes non-uniform by baking after low-speed spin coating is due to the Marangoni effect.

  The same Marangoni effect is considered to occur even when the lower layer resin is baked at high temperature. It can be explained from the Marangoni effect that when a resin material composed only of a monomer is used, a pullback phenomenon from the wafer edge after coating or a phenomenon in which the film thickness becomes non-uniform occurs. The high temperature material has a low surface tension, and the surface tension increases as the temperature moves to the film surface and the temperature decreases. In general, it is more stable in terms of energy when a material having a low surface tension covers the surface of the film. However, since the Marangoni effect is reversed, the material becomes unstable and the film thickness becomes non-uniform.

  On the other hand, the resist underlayer film material of the present invention contains a material having a low surface tension containing fluorine (that is, an acrylonitrile polymer having a repeating unit represented by the general formula (1)). The film surface is covered with a material having a low tension, and instability due to the Marangoni effect can be eliminated. That is, the film thickness uniformity can also be improved.

[Acrylonitrile polymer]
Acrylonitrile polymer is known as a raw material for carbon fiber. By heating the acrylonitrile polymer at a high temperature of 1,000 ° C. or higher in an oxygen-free atmosphere, carbon fibers in an aggregate of benzene rings are formed. It is known that a ring is formed even by heating near 500 ° C. and a high-strength fiber material that forms a carbon fiber precursor is formed although the strength is not as high as that of carbon fiber.

  The acrylonitrile polymer having a repeating unit containing at least one fluorine atom represented by the general formula (1) contained in the resist underlayer film material of the present invention moves to the surface of the resist underlayer film at the time of coating to form a resin layer. It forms and becomes a layer containing a fluorine atom. The acrylonitrile polymer having one or more fluorine atoms covering the surface of the film is cyclized by heating at 300 ° C. or more to become a more rigid film, which increases the effect of suppressing outgassing, and twists the line pattern during dry etching. The effect which suppresses is also acquired.

  As the monomer for obtaining the repeating unit a in the general formula (1), acrylonitrile, methacrylonitrile, 2-fluoroacrylonitrile, 3-fluoroacrylonitrile, 2- (trifluoromethyl) acrylonitrile, 3- (trifluoromethyl) ) Acrylonitrile can be exemplified.

  Specific examples of the monomer for obtaining the repeating unit b in the general formula (1) include the following.

  Further, as a method for synthesizing an acrylonitrile polymer having a repeating unit containing at least one fluorine atom represented by the general formula (1) oriented on the resist underlayer film surface, a monomer that gives the repeating units a and b is an organic compound. An example is a method in which a polymer compound of a copolymer is obtained by adding a radical polymerization initiator in a solvent and performing heat polymerization.

  At this time, as an organic solvent used when polymerizing an acrylonitrile polymer having a repeating unit containing at least one fluorine atom represented by the general formula (1), toluene, benzene, tetrahydrofuran, diethyl ether, dioxane, etc. Can be illustrated. As polymerization initiators, 2,2′-azobisisobutyronitrile (AIBN), 2,2′-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2-azobis (2-methylpropionate) ), Benzoyl peroxide, lauroyl peroxide, and the like. Moreover, as polymerization temperature of said acrylonitrile polymer, 50-80 degreeC is preferable. The reaction time is preferably 2 to 100 hours, more preferably 5 to 20 hours.

[Novolac resin and bisnaphthol derivatives]
The resist underlayer film material of the present invention essentially comprises an acrylonitrile polymer having a repeating unit represented by the general formula (1), and a novolak resin having a repeating unit represented by the general formula (2) and the general formula (3). Any one of the bisnaphthol derivatives shown by these, or both of these is included. That is, it includes an acrylonitrile polymer having a repeating unit represented by the general formula (1) and a novolak resin having a repeating unit represented by the general formula (2), and does not include a bisnaphthol derivative represented by the general formula (3). The acrylonitrile polymer having the repeating unit represented by the general formula (1) and the bisnaphthol derivative represented by the general formula (3) are included, and the novolak resin having the repeating unit represented by the general formula (2) is not included. The acrylonitrile polymer having the repeating unit represented by the general formula (1), the novolak resin having the repeating unit represented by the general formula (2), and the bisnaphthol derivative represented by the general formula (3) may be used. May be included.

  When the resist underlayer film material of the present invention includes a novolak resin having a repeating unit represented by the general formula (2), the resist underlayer film is separated from the resist underlayer film by a naphthalene ring having a relatively small absorption at a wavelength of 193 nm of an ArF excimer laser. Since the condensed aromatic ring is used, the dry etching resistance can be enhanced.

  The novolak resin having a repeating unit represented by the above general formula (2) contained in the resist underlayer film material of the present invention includes an aldehyde derivative having no fluorine atom and a substituted or unsubstituted bisnaphthol derivative having no fluorine atom The condensate is preferable. As the novolak resin used for the resist underlayer film material of the present invention, such a condensate can be suitably used.

  On the other hand, when the resist underlayer film material of the present invention contains a bisnaphthol derivative represented by the above general formula (3) as a monomer component, the embedding property on the stepped substrate is further improved. Usually, the addition of such a monomer component increases the generation of outgas during baking. However, in the resist underlayer film material of the present invention, as described above, at least one or more of the general formula (1) is used. The acrylonitrile polymer having a repeating unit containing a fluorine atom moves to the surface of the resist underlayer film at the time of coating, and a resin layer containing a large amount of this acrylonitrile polymer is formed on the surface of the resist underlayer film. By covering the surface of the resist underlayer film with the acrylonitrile polymer resin layer containing fluorine atoms, the monomer component is prevented from evaporating from the surface of the resist underlayer film during baking and becoming outgas even when the monomer component is included. be able to. This is an effective means for improving the embedding characteristics by suppressing the generation of outgas.

  The resist underlayer film material of the present invention includes an acrylonitrile polymer having a repeating unit represented by the general formula (1), a novolak resin having a repeating unit represented by the general formula (2), and a bis represented by the general formula (3). It is preferable to include all three types of naphthol derivatives.

  Thus, all three types of acrylonitrile polymer having a repeating unit represented by the general formula (1), a novolak resin having a repeating unit represented by the general formula (2), and a bisnaphthol derivative represented by the general formula (3) are used. By including, the improvement of the embedding characteristic and the reduction of outgas can be achieved in a more balanced manner.

More specifically, the straight-chain, branched or cyclic divalent hydrocarbon group having 1 to 38 carbon atoms represented by X ₂ and X ₃ in the above general formula is a straight chain having 1 to 38 carbon atoms. Examples include chain, branched, or cyclic alkylene groups, arylene groups, and aralkylene groups.

  Specific examples of the bisnaphthol derivative that can be used as a monomer for obtaining the novolak resin having the repeating unit represented by the general formula (2) include the following. Moreover, the following can be used also as a bisnaphthol derivative shown by the said General formula (3).

Here, R ²⁵ represents R ⁵ and R ¹² , and R ²⁶ represents R ⁶ and R ¹³ . In addition, the bisnaphthol derivative for obtaining the novolak resin having the repeating unit represented by the general formula (2) and the bisnaphthol derivative represented by the general formula (3) added for improving the embedding property may be the same. They may be non-identical.

Here, when R ⁵ , R ⁶ , R ¹² , and R ¹³ are acid labile groups, these may be the same or non-identical, particularly groups represented by the following formulas (A-1) to (A-3), etc. Can be illustrated.

In the above formula (A-1), R ^L30 is a tertiary alkyl group having 4 to 20 carbon atoms, preferably 4 to 15 carbon atoms, a trialkylsilyl group having an alkyl group having 1 to 6 carbon atoms, or 4 to 20 carbon atoms. Or a substituent represented by the above general formula (A-3). Specific examples of the tertiary alkyl group include tert-butyl group, tert-amyl group, 1,1-diethylpropyl group, 1-ethylcyclopentyl group, 1-butylcyclopentyl group, 1-ethylcyclohexyl group, 1-butylcyclohexyl. Group, 1-ethyl-2-cyclopentenyl group, 1-ethyl-2-cyclohexenyl group, 2-methyl-2-adamantyl group and the like. Specific examples of the trialkylsilyl group include trimethylsilyl group, triethylsilyl group, and the like. Group, dimethyl-tert-butylsilyl group and the like. Specific examples of the oxoalkyl group include 3-oxocyclohexyl group, 4-methyl-2-oxoxan-4-yl group, 5-methyl-2-oxooxolane. A -5-yl group etc. can be illustrated. A1 is an integer of 0-6.

  Specific examples of the acid labile group represented by the formula (A-1) include tert-butoxycarbonyl group, tert-butoxycarbonylmethyl group, tert-amyloxycarbonyl group, tert-amyloxycarbonylmethyl group, 1 1,1-diethylpropyloxycarbonyl group, 1,1-diethylpropyloxycarbonylmethyl group, 1-ethylcyclopentyloxycarbonyl group, 1-ethylcyclopentyloxycarbonylmethyl group, 1-ethyl-2-cyclopentenyloxycarbonyl group, 1 Examples include -ethyl-2-cyclopentenyloxycarbonylmethyl group, 1-ethoxyethoxycarbonylmethyl group, 2-tetrahydropyranyloxycarbonylmethyl group, 2-tetrahydrofuranyloxycarbonylmethyl group and the like.

Further, examples of the tertiary alkyl group include substituents represented by the following formulas (A-1) -1 to (A-1) -10.

Here, R ^L37 is the same or different from each other, a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 17 carbon atoms, and R ^L38 is a hydrogen atom or 1 carbon atom. 10 to 10 linear, branched, or cyclic alkyl groups. R ^L39 is a linear, branched, or cyclic alkyl group having 6 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms that is the same or different from each other. A1 is as described above.

In the above formula (A-2), R ^L31 and R ^L32 are a hydrogen atom or a linear, branched, or cyclic alkyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a cyclopentyl group, a cyclohexyl group, a 2-ethylhexyl group, and an n-octyl group. . R ^L33 is a monovalent hydrocarbon group which may have a hetero atom such as an oxygen atom having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, and is particularly linear, branched or cyclic. And a group in which some of these hydrogen atoms are substituted with a hydroxy group, an alkoxy group, an oxo group, an amino group, an alkylamino group, etc., specifically, the following substituted alkyl groups are exemplified. it can.

R ^L31 and R ^L32 , R ^L31 and R ^L33 , R ^L32 and R ^L33 may be combined to form a ring with the carbon atom to which they are bonded, and if a ring is formed, it is involved in the formation of the ring R ^L31 , R ^L32 and R ^L33 are each a linear or branched alkylene group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms. As a ring, C3-C10 is preferable and C4-C10 is especially preferable.

  Of the acid labile groups represented by the above formula (A-2), examples of the linear or branched groups include those of the following formulas (A-2) -1 to (A-2) -69. be able to.

  Among the acid labile groups represented by the above formula (A-2), the cyclic ones include tetrahydrofuran-2-yl group, 2-methyltetrahydrofuran-2-yl group, tetrahydropyran-2-yl group, 2- Examples thereof include a methyltetrahydropyran-2-yl group.

Moreover, the novolak resin which has a repeating unit shown by the said General formula (2) which is a base resin by the acid labile group represented by the following general formula (A-2a) or (A-2b) is intermolecular or It may be crosslinked in the molecule.

In the above formula, R ^L40 and R ^L41 are a hydrogen atom or a linear, branched, or cyclic alkyl group having 1 to 8 carbon atoms, or R ^L40 and R ^L41 are bonded to each other and bonded to each other. You may form a ring with an atom. In the case of forming a ring, R ^L40 and R ^L41 are linear or branched alkylene groups having 1 to 8 carbon atoms. R ^L42 is a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms. B1 and D1 are 0 or an integer of 1 to 10, preferably 0 or 1 to 5. C1 is an integer of 1 to 7, preferably 1 to 3.

  In the above formula, A is a (C1 + 1) -valent aliphatic or alicyclic saturated hydrocarbon group, aromatic hydrocarbon group, or heterocyclic group having 1 to 50 carbon atoms, and these groups contain a heteroatom. Alternatively, part of the hydrogen atoms bonded to the carbon atoms of these groups may be substituted with a hydroxy group, a carboxyl group, a carbonyl group, or a fluorine atom. A is preferably a divalent to tetravalent C1-C20 linear, branched, or cyclic alkylene group, an alkyltriyl group, an alkyltetrayl group, or an arylene group having 6 to 30 carbon atoms. In these groups, a hetero atom may be interposed. Further, a part of hydrogen atoms bonded to carbon atoms of these groups may be substituted with a hydroxy group, a carboxyl group, an acyl group, or a halogen atom. B is a group represented by -CO-O-, -NHCO-O-, or -NHCONH-.

Specific examples of the crosslinked acetal groups represented by the general formulas (A-2a) and (A-2b) include those represented by the following formulas (A-2) -70 to (A-2) -77.

Next, in the above formula (A-3), R ^L34 , R ^L35 , and R ^{L36 each} represent a monovalent hydrocarbon group such as a linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms or 2 carbon atoms. -20 linear, branched, or cyclic alkenyl groups. In addition, these groups may contain hetero atoms such as oxygen, sulfur, nitrogen and fluorine, and R ^L34 and R ^L35 , R ^L34 and R ^L36 , R ^L35 and R ^L36 are bonded to each other, and carbons to which these are bonded. You may form a C3-C20 alicyclic with an atom.

  The tertiary alkyl group represented by the above formula (A-3) includes a tert-butyl group, triethylcarbyl group, 1-ethylnorbornyl group, 1-methylcyclohexyl group, 1-ethylcyclopentyl group, 2- (2 -Methyl) adamantyl group, 2- (2-ethyl) adamantyl group, tert-amyl group and the like.

Furthermore, specific examples of the tertiary alkyl group include the following formulas (A-3) -1 to (A-3) -18.

In the above formulas (A-3) -1 to (A-3) -18, R ^L43 is the same or different linear, branched, or cyclic alkyl group having 1 to 8 carbon atoms, or 6 to 6 carbon atoms. An aryl group such as 20 phenyl groups. R ^L44 and R ^L46 are a hydrogen atom or a linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms. R ^L45 is an aryl group such as a phenyl group having 6 to 20 carbon atoms.

Furthermore, as shown in the following formulas (A-3) -19 and (A-3) -20, it contains ^RL47 which is a divalent or higher valent alkylene group and an arylene group, and the polymer is intermolecular or intermolecularly crosslinked. It may be. E1 is an integer of 0 to 8, preferably 0 to 6.

  Further, the novolak resin having the repeating unit represented by the general formula (2) may be co-condensed with a monomer other than the above-described bisnaphthol derivative. Specific examples of monomers that can be used in the cocondensation include phenol, o-cresol, m-cresol, p-cresol, 2,3-dimethylphenol, 2,5-dimethylphenol, 3,4-dimethylphenol, 3, 5-dimethylphenol, 2,4-dimethylphenol, 2,6-dimethylphenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, 2-tert-butylphenol, 3-tert-butylphenol, 4 -Tert-butylphenol, 2-phenylphenol, 3-phenylphenol, 4-phenylphenol, 3,5-diphenylphenol, 2-naphthylphenol, 3-naphthylphenol, 4-naphthylphenol, 4-tritylphenol, resorcinol, 2 -Methyl reso Sinol, 4-methylresorcinol, 5-methylresorcinol, catechol, 4-tert-butylcatechol, 2-methoxyphenol, 3-methoxyphenol, 2-propylphenol, 3-propylphenol, 4-propylphenol, 2-isopropylphenol 3-isopropylphenol, 4-isopropylphenol, 2-methoxy-5-methylphenol, 2-tert-butyl-5-methylphenol, pyrogallol, thymol, isothymol, 4,4 ′-(9H-fluorene-9-ylidene ) Bisphenol, 2,2′dimethyl-4,4 ′-(9H-fluorene-9-ylidene) bisphenol, 2,2′diallyl-4,4 ′-(9H-fluorene-9-ylidene) bisphenol, 2,2 'Difluoro- , 4 ′-(9H-fluorene-9-ylidene) bisphenol, 2,2′diphenyl-4,4 ′-(9H-fluorene-9-ylidene) bisphenol, 2,2′dimethoxy-4,4 ′-(9H -Fluorene-9-ylidene) bisphenol, 2,3,2 ', 3'-tetrahydro- (1,1')-spirobiindene-6,6'-diol, 3,3,3 ', 3'-tetra Methyl-2,3,2 ′, 3′-tetrahydro- (1,1 ′)-spirobiindene-6,6′-diol, 3,3,3 ′, 3 ′, 4,4′-hexamethyl-2 , 3,2 ′, 3′-tetrahydro- (1,1 ′)-spirobiindene-6,6′-diol, 2,3,2 ′, 3′-tetrahydro- (1,1 ′)-spirobi Indene-5,5′-diol, 5,5′-dimethyl-3,3 , 3 ′, 3′-tetramethyl-2,3,2 ′, 3′-tetrahydro- (1,1 ′)-spirobiindene-6,6′-diol, 1,2-dihydroxynaphthalene, 1,3 -Dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,4- Dihydroxynaphthalene, 2,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,8-dihydroxynaphthalene, 1-naphthol, 2-naphthol, 2-methyl-1-naphthol, 4-methoxy -1-naphthol, 7-methoxy-2-naphthol, 6-methoxy-2 Naphthol, 3-methoxy-2-naphthol, 1,4-dimethoxynaphthalene, 1,5-dimethoxynaphthalene, 1,6-dimethoxynaphthalene, 1,7-dimethoxynaphthalene, 1,8-dimethoxynaphthalene, 2,3-dimethoxy Naphthalene, 2,6-dimethoxynaphthalene, 2,7-dimethoxynaphthalene, methyl 3-hydroxy-naphthalene-2-carboxylate, naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, 1,2-dimethylnaphthalene, 1,3 -Dimethylnaphthalene, 1,4-dimethylnaphthalene, 1,5-dimethylnaphthalene, 1,6-dimethylnaphthalene, 1,7-dimethylnaphthalene, 1,8-dimethylnaphthalene, 2,3-dimethylnaphthalene, 2,6- Dimethylnaphthalene, 2,7-dimethylnaphthalene 1-ethylnaphthalene, 2-ethylnaphthalene, 1-propylnaphthalene, 2-propylnaphthalene, 1-butylnaphthalene, 2-butylnaphthalene, 1-phenylnaphthalene, 1-cyclohexylnaphthalene, 1-cyclopentylnaphthalene, indene, hydroxyanthracene , Acenaphthylene, acenaphthene, biphenyl, bisphenol, trisphenol, dicyclopentadiene, 1,5-dimethylnaphthalene, substituted or unsubstituted phenolphthalein, phenol red, cresolphthalein, cresol red, thymolphthalein, 4-fluorophenol , 3-fluorophenol, 2-fluorophenol, 4-trifluoromethylphenol, 2,3-difluorophenol, 2,4-difluorophenol, 2 , 5-difluorophenol, 2,6-difluorophenol, 3,4-difluorophenol, 3,5-difluorophenol, 2,3,4-trifluorophenol, 2,3,6-trifluorophenol, 3,4 , 5-trifluorophenol, 4-trifluoromethoxyphenol, 3-trifluoromethoxyphenol, 2-trifluoromethoxyphenol, 4-trifluoromethylthiophenol, 3-trifluoromethylthiophenol, 2-trifluoromethylthiophenol, 2 , 3-ditrifluorophenol, 2,4-ditrifluorophenol, 2,5-ditrifluorophenol, 2,6-ditrifluorophenol, 3,4-ditrifluorophenol, 3,5-ditrifluorophenol, pentafluoro Enol, 3-trifluoromethylphenol, 2-trifluoromethylphenol, 4- (1,1,1,3,3,3-hexafluoro-2-propanol) phenol, 3- (1,1,1,3 , 3,3-hexafluoro-2-propanol) phenol, 3,5-di (1,1,1,3,3,3-hexafluoro-2-propanol) phenol and the like.

  When synthesizing a novolak resin having the repeating unit represented by the general formula (2), other monomers are added to the above-mentioned substituted or unsubstituted bisnaphthol derivative as necessary, and an aldehyde is added thereto. Novolak and polymerize. By making it novolak, the molecular weight increases, and outgassing and particle generation due to low molecular weight substances during baking can be suppressed.

  Examples of the aldehyde that can be used for the synthesis of the novolak resin having the repeating unit represented by the general formula (2) include formaldehyde, trioxane, paraformaldehyde, benzaldehyde, methoxybenzaldehyde, phenylbenzaldehyde, tritylbenzaldehyde, cyclohexylbenzaldehyde, and cyclopentylbenzaldehyde. , Tert-butylbenzaldehyde, naphthalenealdehyde, hydroxynaphthalenealdehyde, anthracenealdehyde, fluorenealdehyde, pyrenealdehyde, methoxynaphthalenealdehyde, dimethoxynaphthalenealdehyde, acetaldehyde, propylaldehyde, phenylacetaldehyde, naphthaleneacetaldehyde, substituted or unsubstituted carboxylnaphthalenealdehyde Toaldehyde, α-phenylpropylaldehyde, β-phenylpropylaldehyde, o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde, o-chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde, o-nitrobenzaldehyde, Examples thereof include m-nitrobenzaldehyde, p-nitrobenzaldehyde, o-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, p-ethylbenzaldehyde, pn-butylbenzaldehyde, furfural, furancarboxaldehyde, thiophene aldehyde and the like. Of these, formaldehyde is particularly preferred.

  Said aldehyde can be used individually or in combination of 2 or more types. Moreover, the usage-amount of the said aldehyde has preferable 0.2-5 mol with respect to 1 mol of substituted or unsubstituted bisnaphthol derivatives, More preferably, it is 0.5-2 mol.

A catalyst can also be used for the condensation reaction of the bisnaphthol derivative and the aldehyde. Specific examples include acidic catalysts such as hydrochloric acid, nitric acid, sulfuric acid, formic acid, oxalic acid, acetic acid, methanesulfonic acid, camphorsulfonic acid, tosylic acid, trifluoromethanesulfonic acid, and the like. The amount of these acidic catalysts used is preferably 1 × 10 ^{−5 to} 5 × 10 ⁻¹ mol with respect to 1 mol of the bisnaphthol derivative.

  As the novolak resin having the repeating unit represented by the general formula (2), those having a weight average molecular weight and a molecular weight of 400 to 20,000 are preferable. More preferred is a range of 500 to 10,000, and particularly preferred is a range of 600 to 10,000. The smaller the molecular weight, the better the embedding characteristics. However, outgassing is likely to occur during baking, so it is preferable to optimize from the viewpoint of embedding characteristics and outgas generation.

  In order to achieve both embedding characteristics and reduction of outgas, the resist underlayer film material of the present invention has the above general formula (2) with respect to 1 part by mass of the acrylonitrile polymer having the repeating unit represented by the above general formula (1). It is preferable to mix the novolak resin having a repeating unit represented by the above formula and the bisnaphthol derivative represented by the general formula (3) in a ratio of 5 to 100 parts by mass in total. By setting such a ratio, reduction of outgas by the resin layer of acrylonitrile polymer having a repeating unit containing at least one fluorine atom represented by the general formula (1), and the general formula (3) Improvement of the embedding property by the bisnaphthol derivative can be achieved particularly in a well-balanced manner.

  Further, when the novolak resin having the repeating unit represented by the general formula (2) is produced, the reaction solution contains an unpolymerized substituted or unsubstituted bisnaphthol derivative (monomer), dimer, trimer, etc. In some cases. Since these unpolymerized monomers and low molecular weight substances contribute to the generation of outgas, it is preferable to remove them as much as possible from the viewpoint of both embedding characteristics and reduction of outgas. In addition, when adding a monomer component, after removing an unpolymerized monomer and a low molecular weight body as mentioned above, it is preferable to add a monomer component of a desired amount separately.

  The resist underlayer film material of the present invention includes an acrylonitrile polymer having a repeating unit containing at least one fluorine atom represented by the general formula (1) and a novolac resin having a repeating unit represented by the general formula (2). And any one or both of bisnaphthol derivatives represented by the following general formula (3), other resins may be blended. Examples of resins that can be blended include phenol, o-cresol, m-cresol, p-cresol, 2,3-dimethylphenol, 2,4-dimethylphenol, 2,5-dimethylphenol, 2,6-dimethylphenol, 3 , 4-dimethylphenol, 3,5-dimethylphenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, 2-tert-butylphenol, 3-tert-butylphenol, 4-tert-butylphenol, 2 -Phenylphenol, 3-phenylphenol, 4-phenylphenol, 3,5-diphenylphenol, 2-naphthylphenol, 3-naphthylphenol, 4-naphthylphenol, 4-tritylphenol, resorcinol, 2-methylresorcinol, 4- Me Luresorcinol, 5-methylresorcinol, catechol, 4-tert-butylcatechol, 2-methoxyphenol, 3-methoxyphenol, 2-propylphenol, 3-propylphenol, 4-propylphenol, 2-isopropylphenol, 3-isopropyl Phenol, 4-isopropylphenol, 2-methoxy-5-methylphenol, 2-tert-butyl-5-methylphenol, pyrogallol, thymol, isothymol, 1-naphthol, 2-naphthol, 2-methyl-1-naphthol, 4 -Dihydroxynaphthalene such as methoxy-1-naphthol, 7-methoxy-2-naphthol and 1,5-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, phenol Talein, phenol red, cresolphthalein, cresol red, thymolphthalein, methyl 3-hydroxy-naphthalene-2-carboxylate, indene, hydroxyindene, benzofuran, hydroxyanthracene, acenaphthylene, biphenyl, bisphenol, trisphenol and aldehyde A novolak resin by reaction etc. can be illustrated. Furthermore, a resin obtained by copolymerizing a phenol compound with dicyclopentadiene, tetrahydroindene, 4-vinylcyclohexene, norbornadiene, 5-vinylnorborna-2-ene, α-pinene, β-pinene, limonene without using an aldehyde Can be illustrated.

  Further, as a monomer component, in addition to the bisnaphthol derivative represented by the general formula (3), hydroxystyrene, alkoxystyrene, hydroxyvinylnaphthalene, alkoxyvinylnaphthalene, (meth) acrylates, vinyl ethers, maleic anhydride, anhydrous A compound selected from itaconic acid and the like can be added. In addition, a substituted or unsubstituted naphthol compound can be added.

  Moreover, a high carbon resin may be used in combination with the resist underlayer film material of the present invention. Examples of such a resin include JP-A Nos. 2004-205658, 2004-205676, and 2004-205585. 2004-271838, 2004-354554, 2005-10431, 2005-49810, 2005-114921, 2005-128509, 2005-250434, 2006-053543, 2006-227391, 2006-259249, 2006-259482, 2006-285095, 2006-293207, 2006-293298, 2007-140461 publication, the same No. 007-171895, No. 2007-199653, No. 2007-316282, No. 2008-26600, No. 2008-65303, No. 2008-96684, No. 2008-257188, No. 2010- 160189, 2010-134437, 2010-170013, 2010-271654, 2008-116677, and 2008-145539 described in the resist underlayer film materials. Resins can be exemplified.

[Organic solvent]
An organic solvent may be further used for the resist underlayer film material of the present invention. As the organic solvent that can be used in the resist underlayer film material of the present invention, a base resin such as the above-mentioned novolak resin, a monomer component, and further an additive such as an acid generator and a crosslinking agent described later can be used. There is no limit. Specifically, the solvents described in paragraphs (0091) to (0092) of JP-A-2007-199653 can be added.

[Crosslinking agent]
As the resist underlayer film, when the silicon-containing intermediate layer film material or the resist upper layer film material is dispensed on the resist underlayer film, it does not dissolve in the silicon-containing intermediate layer film material or the resist upper layer film material; Or the characteristic which does not mix with a resist upper layer film is required. Therefore, it is preferable to add a crosslinking agent to the resist underlayer film material of the present invention in order to crosslink by baking after coating.

  As a crosslinking agent that can be used in the present invention, a melamine compound substituted with at least one group selected from a methylol group, an alkoxymethyl group, and an acyloxymethyl group, a guanamine compound, a glycoluril compound, a urea compound, an epoxy compound, Examples thereof include an isocyanate compound, an azide compound, or a compound containing a double bond such as an alkenyl ether group. These may be used as additives, but may be introduced as pendant groups in the polymer side chain. A compound containing a hydroxy group can also be used as a crosslinking agent.

  Among the specific examples of the crosslinking agent, examples of the epoxy compound further include tris (2,3-epoxypropyl) isocyanurate, trimethylol methane triglycidyl ether, trimethylol propane triglycidyl ether, triethylol ethane triglycidyl ether and the like. it can. Examples of the melamine compound include hexamethylol melamine, hexamethoxymethyl melamine, a compound in which 1 to 6 methylol groups of hexamethylol melamine are methoxymethylated, or a mixture thereof, hexamethoxyethyl melamine, hexaacyloxymethyl melamine, hexamethylol melamine A compound in which 1 to 6 methylol groups are acyloxymethylated or a mixture thereof can be exemplified. Examples of the guanamine compound include tetramethylolguanamine, tetramethoxymethylguanamine, a compound in which 1 to 4 methylol groups of tetramethylolguanamine are methoxymethylated, or a mixture thereof, tetramethoxyethylguanamine, tetraacyloxyguanamine, and tetramethylolguanamine. Examples include compounds in which 1 to 4 methylol groups are acyloxymethylated, or mixtures thereof. Examples of the glycoluril compound include tetramethylol glycoluril, tetramethoxyglycoluril, tetramethoxymethylglycoluril, a compound in which 1 to 4 methylol groups of tetramethylolglycoluril are methoxymethylated, or a mixture thereof, and tetramethylolglycoluril. Examples thereof include compounds in which 1 to 4 methylol groups are acyloxymethylated, or mixtures thereof. Examples of the urea compound include tetramethylol urea, tetramethoxymethyl urea, a compound in which 1 to 4 methylol groups of tetramethylol urea are methoxymethylated, a mixture thereof, tetramethoxyethyl urea, and the like. Examples of the isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate. Examples of the azide compound include 1,1′-biphenyl-4,4′-bisazide and 4,4′-methylidenebis. Examples include azide and 4,4′-oxybisazide.

  Moreover, as a crosslinking agent which forms bridge | crosslinking by an acetal group, the compound which has a some enol ether group in a molecule | numerator can be illustrated. Examples of the crosslinking agent having at least two enol ether groups in the molecule include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,4-butanediol divinyl ether, and tetramethylene glycol. Divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, trimethylolpropane Trivinyl ether, ethylene glycol dipropenyl ether, Liethylene glycol dipropenyl ether, 1,2-propanediol dipropenyl ether, 1,4-butanediol dipropenyl ether, tetramethylene glycol dipropenyl ether, neopentyl glycol dipropenyl ether, trimethylolpropane tripropenyl ether, hexanediol di Examples include propenyl ether, 1,4-cyclohexanediol dipropenyl ether, pentaerythritol tripropenyl ether, pentaerythritol tetrapropenyl ether, sorbitol tetrapropenyl ether, sorbitol pentapropenyl ether, trimethylolpropane tripropenyl ether and the like.

Furthermore, the compound shown below can also be illustrated as a crosslinking agent of the compound which has several enol ether group in a molecule | numerator.

  Since an enol ether group is acetal-bonded to a hydroxy group by heat, thermal crosslinking with an acetal group is performed by adding a compound having a plurality of enol ether groups in the molecule.

  A crosslinking agent having an acid-eliminating tertiary ester group containing at least two or more oxiranes in the molecule can also be added. Specific examples of such a crosslinking agent include those described in JP-A-2006-96848. When such a crosslinking agent is used, as shown in JP-A-2001-226430, oxirane is crosslinked by heat, and the tertiary ester moiety is decomposed by acid.

  Further, the resist underlayer film material of the present invention can be crosslinked by heating at 300 ° C. or higher after spin coating without adding a crosslinking agent as described above. In this case, the polymers are bonded to each other by an oxidative coupling reaction.

[Acid generator]
In addition, an acid generator for further promoting the crosslinking reaction by heat can be added to the resist underlayer film material of the present invention. There are acid generators that generate an acid by thermal decomposition and those that generate an acid by light irradiation, and any of them can be added. Specific examples of the acid generator include materials described in paragraphs (0061) to (0085) of JP-A-2007-199653.

  When the resist underlayer film material of the present invention as described above is used, a resin layer of acrylonitrile polymer having a repeating unit containing at least one fluorine atom represented by the general formula (1) is formed on the resist underlayer film surface. In addition, the presence of the fluorine-containing layer can suppress the generation of outgas even when the resist underlayer film is baked at a high temperature. Further, by adding the bisnaphthol derivative represented by the general formula (3) as a monomer component to the resist underlayer film material, it is possible to achieve both suppression of outgassing and improvement of the step-filling characteristics.

<Pattern formation method>
The present invention is a method for forming a pattern on a substrate by lithography, wherein a resist underlayer film is formed on a substrate to be processed using the resist underlayer film material of the present invention described above, and a silicon-containing intermediate is formed on the resist underlayer film. After forming a silicon-containing intermediate layer film using the layer film material, forming a resist upper layer film using the resist upper layer film material on the silicon-containing intermediate layer film, and exposing the pattern circuit region of the resist upper layer film, Development is performed to form a resist pattern on the resist upper layer film, and the resist upper layer film on which the resist pattern is formed is used as a mask to transfer the pattern to the silicon-containing intermediate layer film by etching. The intermediate layer film is used as a mask to transfer the pattern to the resist underlayer film by etching, and the resist underlayer film to which the pattern is transferred is used as a mask to transfer the pattern. Providing a pattern forming method for forming a pattern by etching the processable substrate.

  Hereinafter, although an example of the pattern formation method of this invention is demonstrated, referring drawings, this invention is not limited to these.

  FIG. 1 is a flowchart showing an example of a pattern forming method of a three-layer process of the present invention using a silicon-containing intermediate layer film material. In the pattern forming method shown in the flow chart of FIG. 1, first, Ii) a resist underlayer film material of the present invention is coated on a layer 2 to be processed on a substrate 1 to form a resist underlayer film 3, and the resist The silicon-containing intermediate layer film material is coated on the lower layer film 3 to form the silicon-containing intermediate layer film 4, and the resist upper layer film material is coated on the silicon-containing intermediate layer film 4 to form the resist upper layer film 5. Next, I-ii) exposes the pattern circuit region 6 of the resist upper layer film 5, I-iii) develops it to form a resist pattern on the resist upper layer film 5 (in the case of a positive resist), and I-iv) Using the resist upper layer film 5 on which the resist pattern is formed as a mask, the pattern is transferred to the silicon-containing intermediate layer film 4 by etching, and Iv) the resist lower layer film using the silicon-containing intermediate layer film 4 on which the pattern is transferred as a mask The pattern is transferred to 3 by etching, and I-vi) Further, the resist underlayer film 3 to which the pattern has been transferred is used as a mask to form a pattern on the layer to be processed 2 by etching.

[Substrate to be processed]
Although it does not specifically limit as a to-be-processed substrate, For example, what formed the to-be-processed layer on the board | substrate can be used. The substrate is not particularly limited, and Si, α-Si, p-Si, SiO ₂ , SiN, SiON, W, TiN, Al, or the like, preferably made of a material different from the layer to be processed. it can. In addition, as a layer to be processed, Si, SiO ₂ , SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, Al-Si, and various Low-k films (low dielectric constant) Film), an etching stopper film thereof, or a Fin-FET stepped substrate, and the like. The thickness of the layer to be processed is preferably 10 to 10,000 nm, particularly preferably 20 to 5,000 nm. .

A hard mask for processing the substrate to be processed may be formed between the substrate to be processed and the resist underlayer film. As the hard mask, when the substrate to be processed is an SiO ₂ -based insulating film substrate, SiN, SiON , P-Si, α-Si, W, W-Si, amorphous carbon, and the like are used. The substrate to be processed is p-Si, W-Si, SiO 2 in the case of the gate electrode such as Al-Si, SiN, SiON or the like is used.

  On the resist underlayer film formed using the resist underlayer film material of the present invention, an intermediate layer film containing an element selected from metals such as silicon, titanium, zirconium and hafnium is preferable. A tri-layer process in which a resist upper layer film is provided on the intermediate layer film is preferably used. As an element contained in the intermediate layer film for the trilayer, silicon is most preferable.

[Silicon-containing interlayer film]
The material for the silicon-containing intermediate layer film is not particularly limited, and a silsesquioxane-based material having absorption at an exposure wavelength described in JP-A-2007-302873 can be used. Further, the silicon-containing intermediate layer film is formed by spin coating. A silicon-containing intermediate layer film made of a silicon oxide film can be formed by spin-coating a silicon-containing intermediate layer film material and baking at a temperature of 150 to 300 ° C.

  The optical constant (n, k value) optimum for the antireflection effect of the silicon-containing intermediate film when applied to the trilayer process is such that the n value is 1.5 to 1.9 and the k value is 0.15 to 0.3. 3. The film thickness is in the range of 20 to 130 nm. As the resist underlayer film, an n value of 1.3 to 1.8, a k value of 0.2 to 0.8, and a film thickness of 50 or more are optimal.

[Resist upper layer film]
The material for the resist upper layer film is not particularly limited, and for example, a known base polymer made of hydrocarbon as shown in JP-A-9-73173 and JP-A-2000-336121 can be used. The thickness of the resist upper layer film is not particularly limited, but is preferably 20 to 500 nm, and particularly preferably 30 to 400 nm.

  When the resist upper layer film is formed using the resist upper layer film material, a spin coat method or the like is suitable as in the case of forming the resist lower layer film. The pre-bake performed after the resist upper layer film is formed by spin coating or the like is preferably 80 to 180 ° C. and 10 to 300 seconds.

  When an inorganic hard mask intermediate layer film is formed in place of the silicon-containing intermediate layer film, as shown in II-i of FIG. 2, a silicon layer between the resist lower layer film 3 and the resist upper layer film 5 is used. Inorganic hard mask intermediate layer film 7 selected from oxide film, silicon nitride film, silicon oxynitride film, silicon carbide film, polysilicon film, titanium nitride film, titanium oxide film, titanium carbide film, zirconium oxide film, or hafnium oxide film May be formed.

[Inorganic hard mask interlayer film]
The material of the inorganic hard mask intermediate layer film is not particularly limited. For the inorganic hard mask intermediate layer film containing an element selected from metals such as silicon, titanium, zirconium and hafnium, in particular, for the titanium-containing intermediate film, materials described in JP-A-2014-178602 can be used. An inorganic hard mask intermediate layer film is formed on the resist lower layer film, and a resist upper layer film is provided thereon to form a trilayer process. As the inorganic hard mask intermediate layer film material, p-Si, SiN, SiON, SiC, TiN, TiO ₂ , TiC, ZrO ₂ , and HfO ₂ are particularly suitable.

  The inorganic hard mask intermediate layer film can be formed by a CVD method, an ALD method, a sputtering method, or the like, and is heated at 300 to 800 ° C. during the film formation. For this reason, in order to prevent generation of outgas from the resist underlayer film during CVD or sputtering, the resist underlayer film is preferably heated at 300 to 800 ° C. in advance. If a large amount of outgas is generated at this time, dirt will adhere to the top plate of the hot plate, and if the material adhering to the top plate falls to the wafer surface, it will cause defects. However, the resist underlayer film material of the present invention is as described above. In addition, since generation of outgas during high-temperature baking can be suppressed, the present invention can also be applied to the case where such an inorganic hard mask intermediate layer film is formed.

  Further, when an organic antireflection film is formed on the inorganic hard mask intermediate film to form a four-layer resist film, as shown in III-i) of FIG. The organic antireflection film 8 may be formed by coating an organic antireflection film material. In this case, a four-layer process is performed.

[Organic antireflection coating]
The organic antireflection film material is not particularly limited, and known materials can be used.

  Further, in the case of forming a hydrocarbon film and a silicon-containing intermediate layer film thereon to form a five-layer resist film, as shown in IV-i) of FIG. 4, hydrocarbons are formed on the inorganic hard mask intermediate layer film 7. The hydrocarbon film 9 may be formed by spin coating using a film material, and the silicon-containing intermediate film 4 may be formed thereon using a silicon-containing intermediate film material. In this case, a 5-layer process is performed.

[Hydrocarbon film]
It does not specifically limit as a hydrocarbon film material, A well-known thing can be used.

[Pattern formation]
(Three-layer process)
First, a method for forming a resist underlayer film using the resist underlayer film material of the present invention will be described. It can be formed on the substrate by a spin coating method or the like in the same way as a normal photoresist film forming method. After applying the resist underlayer film material on the substrate to be processed by spin coating or the like to form the resist underlayer film, the organic solvent is evaporated to prevent mixing with the resist upper layer film, or a crosslinking reaction is performed. It is preferable to bake to promote. The baking temperature is preferably in the range of 80 to 800 ° C. and preferably in the range of 10 to 300 seconds. Although the thickness of the resist underlayer film is appropriately selected, it is preferably 5 to 100,000 nm, particularly preferably 10 to 50,000 nm. With such a thickness, a high antireflection effect can be obtained.

  In the case of the three-layer process, as shown in Ii in FIG. 1, after forming the resist underlayer film 3 on the processing layer 2 laminated on the substrate 1, the silicon-containing intermediate layer film 4 is formed. Then, a resist upper layer film 5 is formed thereon.

  Also, a resist protective film can be formed on the resist upper layer film. The resist protective film may be provided for the purpose of preventing elution of an additive such as an acid generator from the resist upper layer film and improving the sliding property during immersion exposure. The resist protective film can also have an antireflection function. The resist protective film includes a water-soluble one and a water-insoluble one. There are two types of water-insoluble resist protective films, one that dissolves in an alkali developer and another that does not dissolve in an alkali developer and peels off with an organic solvent. There are only process advantages and is preferable. When applied to negative pattern formation by organic solvent development, the latter solvent peeling type can be peeled off simultaneously with development. When soluble in an alkali developer, a polymer compound having an α-trifluoromethylhydroxy group dissolved in a higher alcohol having 4 or more carbon atoms or an ether compound having 8 to 12 carbon atoms is used.

  As a method for forming the resist protective film, a protective film material is spin-coated on the resist upper layer film after pre-baking, and is formed by pre-baking. The thickness of the resist protective film is preferably in the range of 10 to 200 nm. After dry or immersion exposure, post-exposure baking (PEB) is performed, and development is performed with an alkali developer for 10 to 300 seconds. As the alkali developer, a 2.38 mass% tetramethylammonium hydroxide aqueous solution is generally widely used. When a resist protective film soluble in the developer is used, the resist protective film can be peeled off and the resist upper layer film can be developed simultaneously.

  Formation of the resist pattern of the resist upper layer film can be performed according to a conventional method. A resist pattern can be obtained by exposing the pattern circuit region of the resist upper layer film and performing PEB and development. When a silicon-containing interlayer film in which an acid generator is added to a polymer pendant with a silicon-containing acid labile group is applied, a silicon-containing interlayer film pattern is obtained simultaneously with formation of a resist pattern by exposure and development. Can do.

  At this time, if water remains on the resist upper layer film before PEB, the water sucks out the acid in the resist upper layer film into PEB, and there is a possibility that the pattern cannot be formed. Therefore, in order to completely remove the water on the resist protective film before PEB, the shape of the nozzle used for spin drying before PEB, purging of the film surface with dry air or nitrogen, or water recovery on the stage after exposure, It is preferable to dry or recover the water on the membrane by optimizing the water recovery process.

  First, the pattern circuit region 6 of the resist upper layer film 5 is exposed (FIG. 1, I-ii)), and PEB and development are performed to form a resist pattern on the resist upper layer film 5 (FIG. 1, I-iii). Using the obtained resist pattern as a mask, the silicon-containing intermediate layer film 4 is etched using CF-based gas to transfer the pattern to the silicon-containing intermediate layer film 4 (FIG. 1, I-iv)).

  Here, for the development, a paddle method using an alkaline aqueous solution, a dip method or the like is used, and a paddle method using a 2.38 mass% aqueous solution of tetramethylammonium hydroxide is particularly preferable. First, it is treated with a developer at room temperature for 10 seconds to 300 seconds, then rinsed with pure water, and dried by spin drying or nitrogen blowing. The exposed portion of the positive resist is dissolved by alkali development, and the exposed portion is insoluble in the case of a negative resist.

  A negative pattern can also be formed by organic solvent development. Developers used at this time are 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methyl acetophenone, propyl acetate, Butyl acetate, isobutyl acetate, amyl acetate, butenyl acetate, isoamyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl valerate, methyl pentenoate, methyl crotonic acid, ethyl crotonic acid, methyl propionate, Ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate 1 selected from methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, 2-phenylethyl acetate, etc. More than a seed solvent.

Next, using the resist pattern and the silicon-containing intermediate layer film as a mask, the pattern is transferred to the resist underlayer film 3 by dry etching such as oxygen plasma (FIG. 1, Iv). Dry etching of the resist underlayer film formed using the resist underlayer film material of the present invention is preferably performed using an etching gas containing oxygen gas or hydrogen gas. In addition to oxygen gas or hydrogen gas, it is possible to add an inert gas such as He or Ar, CO, CO ₂ , NH ₃ , SO ₂ , N ₂ , NO ₂ gas, or the like.

  Further, it is preferable to use a material not containing a polymer containing silicon atoms as the resist upper layer film material, and an etching gas containing oxygen gas or hydrogen gas when etching the resist lower layer film. By using such an etching gas, it is possible to simultaneously remove the resist upper layer film and etch the resist lower layer film.

Further, after the pattern of the silicon-containing intermediate layer film is removed, the pattern 2 is formed by etching the layer 2 to be processed using the pattern of the resist underlayer film as a mask (FIG. 1, I-vi)). At this time, if the work layer 2 is SiO ₂ , SiN or the like, an etching gas containing a chlorofluorocarbon gas contains chlorine or bromine gas if it is polysilicon (p-Si), Al, W or the like. An etching gas is preferred. When ions are implanted, it is not always necessary to process the substrate to be processed, and ions are implanted using the resist underlayer film pattern as a mask.

  An example of the pattern forming method of the trilayer for forming the inorganic hard mask film of the present invention is shown in FIG. In the pattern forming method shown in the flow chart of FIG. 2, II-i) the resist underlayer film material of the present invention is coated on the layer 2 to be processed on the substrate 1 to form the resist underlayer film 3. An inorganic hard mask film material is coated to form an inorganic hard mask intermediate film 7, and a resist upper film material is coated on the inorganic hard mask intermediate film 7 to form a resist upper film 5, II-ii The pattern circuit region 6 is exposed, II-iii) is developed to form a resist pattern on the resist upper layer film 5 (in the case of a positive resist), and II-iv) the resist upper layer film 5 on which the resist pattern is formed The pattern is transferred to the inorganic hard mask film 7 by etching as a mask, and II-v) the inorganic hard mask intermediate layer film 7 to which the pattern is transferred is used as a mask. The pattern etching is transferred to strike the lower film 3, II-vi) Further, the pattern to form a pattern by etching the layer to be processed 2 in the resist underlayer film 3 which has been transferred to the mask. At this time, the inorganic hard mask intermediate layer film may be etched in accordance with a conventional method.

(4-layer process)
Next, the pattern forming method of the four-layer process of the present invention will be described. In the pattern forming method shown in the flow chart of FIG. 3, III-i) a resist underlayer film material of the present invention is coated on a layer 2 to be processed on a substrate 1 to form a resist underlayer film 3. An inorganic hard mask film material is coated to form an inorganic hard mask intermediate film 7, and an organic antireflection film material is coated on the inorganic hard mask intermediate film 7 to form an organic antireflection film 8. A resist upper layer film material is coated on the prevention film 8 to form a resist upper layer film 5 to form a four-layer resist film. III-ii) The pattern circuit region 6 is exposed and III-iii) The developed resist upper layer A resist pattern is formed on the film 5 (in the case of a positive resist), and III-iv) an organic antireflection film using the resist upper layer film 5 on which the resist pattern is formed as a mask III-v) The pattern was transferred to the inorganic hard mask intermediate film 7 using the organic antireflection film 8 on which the pattern was formed as a mask, and III-vi) the pattern was transferred. The pattern is transferred to the resist underlayer film 3 by etching using the inorganic hard mask film 7 as a mask. III-vii) Further, the pattern is formed by etching on the layer 2 to be processed using the resist underlayer film 3 to which the pattern is transferred as a mask. To do.

  At this time, the organic antireflection film may be etched according to a conventional method. Further, the etching of the organic antireflection film may be performed continuously with the etching of the inorganic hard mask intermediate layer film 7, or only the organic antireflection film 8 is etched and then the etching apparatus is changed. The inorganic hard mask intermediate layer film 7 may be etched (FIG. 3, III-iv), III-v)).

(5-layer process)
Next, the pattern forming method of the 5-layer process of the present invention will be described. In the pattern forming method shown in the flow chart of FIG. 4, IV-i) The resist underlayer film material of the present invention is coated on the processing layer 2 on the substrate 1 to form the resist underlayer film 3. An inorganic hard mask intermediate film material is coated to form an inorganic hard mask intermediate film 7, and a hydrocarbon film 9 is formed on the inorganic hard mask intermediate film 7 using a hydrocarbon film material by spin coating. A silicon-containing intermediate layer film 4 is formed on the hydrocarbon film 9 using a silicon-containing intermediate layer film material, and a resist upper layer film material is coated on the silicon-containing intermediate layer film 4 to form a resist upper layer film 5. A 5-layer resist film is formed. IV-ii) The pattern circuit region 6 is exposed, and IV-iii) is developed to form a resist pattern on the resist upper layer film 5 (in the case of a positive resist). IV-iv) The pattern is transferred to the silicon-containing intermediate layer film 4 by etching using the resist upper layer film 5 on which the resist pattern is formed as a mask. IV-v) Hydrocarbon using the silicon-containing intermediate layer film 4 on which the resist pattern is formed as a mask The pattern is transferred to the film 9 by etching. IV-vi) The pattern is transferred to the inorganic hard mask intermediate film 7 by using the hydrocarbon film 9 to which the pattern is transferred as a mask. IV-vii) Using the transferred inorganic hard mask film 7 as a mask, the pattern is transferred to the resist underlayer film 3 by etching. IV-viii) Further, using the resist underlayer film 3 to which the pattern is transferred as a mask, etching is performed on the layer 2 to be processed. Form a pattern. At this time, the hydrocarbon film may be etched in accordance with a conventional method.

  As described above, the pattern forming method of the present invention using the resist underlayer film material of the present invention can sufficiently embed a substrate and suppress the generation of outgas. It is possible to greatly reduce defects during microfabrication in the process. Therefore, the resist underlayer film and pattern forming method of the present invention are particularly required to suppress the occurrence of outgassing at the time of baking of the resist underlayer film, which is a source of defects, as well as embedding a trench pattern having a thin co-pitch. It is suitable for manufacturing a three-dimensional device such as an FET.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not limited by these description.

<Synthesis of an acrylonitrile polymer having a repeating unit containing at least one fluorine atom represented by the general formula (1)>

[Synthesis Example 1-1]
To a 2 L flask, 5.3 g of acrylonitrile and 12.1 g of 2-trifluoromethylacrylonitrile were added, and 20 g of tetrahydrofuran was added as a solvent, followed by stirring. The reaction vessel was cooled to −70 ° C. under a nitrogen atmosphere, degassed under reduced pressure, and then nitrogen blowing was repeated three times. After further raising the temperature to room temperature, 1.2 g of AIBN (azobisisobutyronitrile) as a polymerization initiator was added and stirred, and the temperature was raised to 60 ° C., followed by reaction for 15 hours. The white solid obtained by precipitating the reaction solution thus obtained in 1 L of isopropyl alcohol and filtering was dried under reduced pressure at 60 ° C. to obtain a white polymer. Furthermore, when the obtained polymer was analyzed by ¹³ C, ¹ H-NMR (nuclear magnetic resonance) and GPC (gel permeation chromatography), the following analysis results were obtained. This obtained polymer is referred to as “acrylonitrile polymer 1” and is shown below.

Acrylonitrile polymer 1
Copolymer composition ratio (molar ratio)
Acrylonitrile: 2-trifluoromethylacrylonitrile = 0.52: 0.48
Weight average molecular weight (Mw) = 45,300
Molecular weight distribution (Mw / Mn) = 2.21

[Synthesis Example 1-2]
In the same manner as in Synthesis Example 1-1, 9.4 g of acrylonitrile, 6.7 g of 2,2,2-trifluoroethyl methacrylate, and 20 g of tetrahydrofuran as a solvent were added to a 2 L flask to obtain a white polymer. Further, when the obtained polymer was analyzed in the same manner as described above, the following analysis results were obtained. This obtained polymer is referred to as “acrylonitrile polymer 2” and is shown below.

Acrylonitrile polymer 2
Copolymer composition ratio (molar ratio)
Acrylonitrile: 2,2,2-trifluoroethyl methacrylate = 0.78: 0.22
Weight average molecular weight (Mw) = 31,300
Molecular weight distribution (Mw / Mn) = 1.98

[Synthesis Example 1-3]
In the same manner as in Synthesis Example 1-1, 9.4 g of acrylonitrile, 6.3 g of 2,2,2-trifluoroethyl vinyl ether, and 20 g of tetrahydrofuran as a solvent were added to a 2 L flask to obtain a white polymer. Further, when the obtained polymer was analyzed in the same manner as described above, the following analysis results were obtained. This obtained polymer is referred to as “acrylonitrile polymer 3” and is shown below.

Acrylonitrile polymer 3
Copolymer composition ratio (molar ratio)
Acrylonitrile: 2,2,2-trifluoroethyl vinyl ether = 0.75: 0.25
Weight average molecular weight (Mw) = 38,800
Molecular weight distribution (Mw / Mn) = 1.91

[Synthesis Example 1-4]
In the same manner as in Synthesis Example 1-1, 9.4 g of acrylonitrile, 7.6 g of 2,3,4,5,6-pentafluorostyrene and 20 g of tetrahydrofuran as a solvent were added to a 2 L flask to obtain a white polymer. It was. Further, when the obtained polymer was analyzed in the same manner as described above, the following analysis results were obtained. This obtained polymer is referred to as “acrylonitrile polymer 4” and is shown below.

Acrylonitrile polymer 4
Copolymer composition ratio (molar ratio)
Acrylonitrile: 2,3,4,5,6-pentafluorostyrene = 0.75: 0.25
Weight average molecular weight (Mw) = 23,100
Molecular weight distribution (Mw / Mn) = 1.86

[Synthesis Example 1-5]
In the same manner as in Synthesis Example 1-1, 9.4 g of acrylonitrile, 4.5 g of methacrylic acid 5,4.5 g of methacrylic acid, and 20 g of tetrahydrofuran as a solvent in a 2 L flask. This was added to obtain a white polymer. Further, when the obtained polymer was analyzed in the same manner as described above, the following analysis results were obtained. This obtained polymer is referred to as “acrylonitrile polymer 5” and is shown below.

Acrylonitrile polymer 5
Copolymer composition ratio (molar ratio)
Acrylonitrile: methacrylic acid 5,5,4,4,3,3,2,2-octafluoropentyl = 0.85: 0.15
Weight average molecular weight (Mw) = 35,600
Molecular weight distribution (Mw / Mn) = 1.91

<Synthesis of novolak resin having a repeating unit represented by the general formula (2)>
[Synthesis Example 2-1]
45 g of 6,6 ′-(9H-fluorene-9,9-diyl) di (2-naphthol), 120 g of a 37 mass% formalin aqueous solution, 5 g of oxalic acid and 50 g of dioxane were added and stirred at 100 ° C. for 24 hours. After the reaction, the product was dissolved in 500 ml of methyl isobutyl ketone and the catalyst and metal impurities were removed by sufficient water washing, and then the water and solvent were removed under reduced pressure by reducing the pressure to 150 ° C. and 2 mmHg to obtain the novolak resin 1 shown below.

Novolac resin 1
Molecular weight (Mw) = 3,100
Dispersity (Mw / Mn) = 3.88

[Synthesis Example 2-2]
In the same manner as in Synthesis Example 2-1, 45 g of α-naphtholphthalein, 120 g of a 37 mass% formalin aqueous solution, 5 g of oxalic acid, and 50 g of dioxane were added to obtain a novolak resin 2 shown below.

Novolac resin 2
Molecular weight (Mw) = 2,100
Dispersity (Mw / Mn) = 3.67

[Synthesis Example 2-3]
In the same manner as in Synthesis Example 2-1, 45 g of naphthofluorescein, 120 g of a 37 mass% formalin aqueous solution, 5 g of oxalic acid, and 50 g of dioxane were added to obtain a novolak resin 3 shown below.

Novolac resin 3
Molecular weight (Mw) = 2,600
Dispersity (Mw / Mn) = 3.55

[Synthesis Example 2-4]
45 g of 6,6 ′-(9H-fluorene-9,9-diyl) di (2-naphthol), 60 g of a 37 mass% formalin aqueous solution, 5 g of oxalic acid and 50 g of dioxane were added and stirred at 80 ° C. for 24 hours. After the reaction, the product was dissolved in 500 ml of methyl isobutyl ketone and the catalyst and metal impurities were removed by washing with sufficient water. Then, the pressure was reduced to 150 ° C. and 2 mmHg, and the water and the solvent were removed under reduced pressure to obtain the novolak resin 4 shown below.

Novolac resin 4
Molecular weight (Mw) = 1,100
Dispersity (Mw / Mn) = 3.86

(Examples 1-1 to 1-10, Comparative Examples 1-1 and 1-2)
[Preparation of resist underlayer film material]
The acrylonitrile polymers 1 to 5, the novolak resins 1 to 4 and the monomers 1 to 5 shown below are shown in Table 1 in an organic solvent containing 0.1% by mass of FC-4430 (manufactured by Sumitomo 3M). Resist lower layer film materials (lower layer film materials 1 to 10 and comparative lower layer film materials 1 and 2) were prepared by dissolving and filtering through a filter made of a fluororesin having a pore diameter of 0.1 μm.

Monomers 1-5

<Refractive index measurement>
The resist underlayer film material prepared above (underlayer film materials 1 to 10, comparative underlayer film materials 1 and 2) is applied on a silicon (Si) substrate, and is baked at 350 ° C. for 60 seconds in an air atmosphere. A resist underlayer film having a thickness of 100 nm was formed. After the formation of the resist underlayer film, the incident angle is variable. A. The refractive index (n, k) at a wavelength of 193 nm was determined with a spectroscopic ellipsometer (VASE) manufactured by Woollam. The results are shown in Table 1.

ＰＧＭＥＡ：プロピレングリコールモノメチルエーテルアセテート

PGMEA: Propylene glycol monomethyl ether acetate

<Sublimation measurement>
The manufactured resist underlayer film materials (underlayer film materials 1 to 10 and comparative underlayer film materials 1 and 2) were respectively applied on a Si substrate, fired under the atmosphere described in Table 2 in an air atmosphere, and baked. Particles generated in the hot plate oven were measured for the number of particles having a size of 0.3 μm and 0.5 μm using a particle counter KR-11A manufactured by Rion. The results are shown in Table 2.

  From the above results, the lower layer film materials 1 to 10 and the comparative lower layer film material 2 have less generation of particles during baking than the comparative lower layer film material 1, and thus the generation of outgas is reduced. It turned out to be difficult to contaminate. Moreover, it turned out that any underlayer film material has sufficient heat resistance.

<Embedded evaluation on stepped substrate>
(Examples 2-1 to 2-10, Comparative examples 2-1 and 2-2)
As the step substrate, a Si substrate on which a dense hole pattern of SiO ₂ film having a film thickness of 500 nm, a size of 160 nm, and a pitch of 320 nm was formed was used. The manufactured resist underlayer film material (underlayer film materials 1 to 10, comparative underlayer film materials 1 and 2) is applied on the SiO ₂ film of the stepped substrate so as to have a film thickness of 100 nm on a flat Si substrate, and then the wafer. Was observed by SEM (scanning electron microscope) to see if the resist underlayer film material was buried to the bottom of the hole. The results are shown in Table 3.

  From the results shown in Table 3, it can be seen that the lower layer film materials 1 to 10 have good embedding characteristics even in a high-aspect stepped substrate and, together with the results in Table 2, suppress the generation of outgas. . On the other hand, in Comparative Examples 1-1 and 1-2, it has been found that the securing of the embedding characteristic and the reduction of the outgas are not compatible.

<Preparation of silicon-containing interlayer film material>
The silicon-containing polymer and acid generator PAG1 shown below are dissolved in an organic solvent containing 0.1% by mass of FC-4430 (manufactured by Sumitomo 3M) at a ratio shown in Table 4, and the pore diameter is 0.1 μm. A silicon-containing interlayer film material was prepared by filtering with a fluororesin filter. The silicon-containing intermediate layer film material prepared above was applied onto a Si substrate and baked at 200 ° C. for 60 seconds to form silicon-containing intermediate layer films each having a thickness of 40 nm. After the formation of the silicon-containing intermediate layer film, the incident angle variable J.P. A. The refractive index (n, k) at a wavelength of 193 nm was determined with a spectroscopic ellipsometer (VASE) manufactured by Woollam, and the results are shown in Table 4.

ＰＧＥＥ：プロピレングリコールエチルエーテル

PGEE: Propylene glycol ethyl ether

<Preparation of resist upper layer film material>
The resist polymer, acid generator PAG2, and quencher shown below were dissolved in an organic solvent containing 0.1% by mass of FC-4430 (manufactured by Sumitomo 3M) at a ratio shown in Table 5 to obtain a pore size of 0. A resist upper layer film material (ArF resist film material) was prepared by filtering through a 1 μm fluororesin filter.

Resist polymer
Molecular weight (Mw) = 7,500
Dispersity (Mw / Mn) = 1.92

<Pattern etching test>
(Examples 3-1 to 3-10, Comparative examples 3-1 and 3-2)
The produced resist underlayer film forming materials (underlayer film materials 1 to 10, comparative underlayer film materials 1 and 2) are applied onto a 300 mm Si wafer substrate on which an SiO ₂ film having a thickness of 80 nm is formed, and 300 in an air atmosphere. Bake at 60 ° C. for 60 seconds, and then further baked at 400 ° C. for 60 seconds in a nitrogen stream to form a resist underlayer film having a thickness of 100 nm. The silicon-containing intermediate layer material prepared above is applied thereon and baked at 200 ° C. for 60 seconds to form an intermediate layer film having a thickness of 35 nm. Then, an ArF resist film material is applied thereon at 105 ° C. The resist film for ArF with a film thickness of 100 nm was formed by baking for 60 seconds.

  Next, the Si wafer substrate on which the three-layer film was formed as described above was subjected to an ArF immersion exposure apparatus (manufactured by Nikon; NSR-S610C, NA1.30, σ0.98 / 0.65, 35-degree dipole s-polarized light Exposure with illumination, 6% halftone phase shift mask), baking (PEB) at 100 ° C. for 60 seconds, development with 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution for 30 seconds, 43 nm 1: 1 positive A mold line and space pattern was obtained.

Further, the pattern was transferred to the silicon-containing intermediate layer film by dry etching using an etching apparatus Telius manufactured by Tokyo Electron Co., Ltd. using the formed resist pattern as a mask. Similarly, by dry etching, the silicon-containing intermediate layer film to which the pattern is transferred is used as a mask, the pattern is transferred to the resist underlayer film, and the pattern is transferred to the SiO ₂ film using the resist underlayer film to which the pattern is transferred as a mask. did.

Etching conditions are as shown below.
Transfer conditions to silicon-containing interlayer film Chamber pressure 10.0 Pa
RF power 1,500W
CF ₄ gas flow rate 15 sccm (mL / min)
O ₂ gas flow rate 75 sccm (mL / min)
Time 15sec

Transfer conditions to resist underlayer chamber pressure 2.0 Pa
RF power 500W
Ar gas flow rate 75 sccm (mL / min)
O ₂ gas flow rate 45 sccm (mL / min)
Time 120sec

Transfer conditions to SiO ₂ film Chamber pressure 2.0 Pa
RF power 2,200W
C ₅ F ₁₂ gas flow rate 20 sccm (mL / min)
C ₂ F ₆ gas flow rate 10 sccm (mL / min)
Ar gas flow rate 300sccm (mL / min)
O ₂ 60 sccm (mL / min)
90 seconds

Using an electron microscope (S-4700) manufactured by Hitachi, Ltd., the wafer was cleaved and the pattern cross section was observed, and the pattern shape after etching in each etching stage and the pattern variation after etching of the SiO ₂ film were compared. . The results are shown in Table 6.

  From the results shown in Table 6 above, it was found that if the resist underlayer film material of the present invention is used, a good pattern can be formed even after dry etching as in the conventional resist underlayer film. It was also found that any lower layer film material has sufficient dry etching resistance.

DESCRIPTION OF SYMBOLS 1 ... Board | substrate, 2 ... Processed layer, 3 ... Resist underlayer film, 4 ... Silicon containing intermediate | middle layer film,
5 ... Resist upper layer film, 6 ... Pattern circuit region, 7 ... Inorganic hard mask intermediate layer film,
8 ... Organic antireflection film, 9 ... Hydrocarbon film.

Claims (12)

An acrylonitrile polymer having a repeating unit containing at least one fluorine atom represented by the following general formula (1), a novolak resin having a repeating unit represented by the following general formula (2), and the following general formula (3) A resist underlayer film material containing either or both of bisnaphthol derivatives.

(In the formula, R ¹ and R ² are a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R ³ is a single bond, a phenylene group, or an alkylene group having 1 to 11 carbon atoms. R ⁴ Is a fluorine atom, or a C1-C10 linear, branched or cyclic alkyl group having at least one fluorine atom, a C2-C10 alkenyl group, or a C6-C10 Which may have a hydroxy group, an alkoxy group, an acyl group, a sulfoxide group, a sulfone group, or a sulfonamide group, wherein R ⁵ , R ⁶ , R ¹² , and R ¹³ are a hydrogen atom, acid labile groups, and one of a glycidyl group, or a straight, branched, or cyclic alkyl group, an acyl group, or alkoxycarbonyl .R ^7, R ⁸ is a carbonyl group Any one of an elementary atom, a hydroxy group, and an alkoxy group having 1 to 4 carbon atoms, or a straight chain having 1 to 10 carbon atoms which may have a hydroxy group, an alkoxy group, an acyloxy group, an ether group, or a sulfide group A branched, or cyclic alkyl group, an alkenyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms R ¹⁴ and R ¹⁵ are the same groups or halogen atoms as R ⁷ and R ⁸ R ⁹ , R ¹⁰ , R ¹⁶ and R ¹⁷ are hydrogen atoms, or are ether bonds formed by combining R ⁹ and R ¹⁰ , R ¹⁶ and R ^17, and R ¹¹ is a hydrogen atom. Or an alkyl group having 1 to 6 carbon atoms which may have a hydroxy group, an alkoxy group, an acyloxy group, an ether group, a sulfide group, a chloro group or a nitro group; Kenyir group, or an aryl group having a carbon number of 6 to 10 .X ₁ is a phenylene group, an ether group, or an ester group .X _2, or X ₃ is a single bond, or a hydroxy group, a carboxyl group, an ether Or a straight-chain, branched or cyclic divalent hydrocarbon group having 1 to 38 carbon atoms which may have a lactone ring, and when X ₂ is a divalent hydrocarbon group, R ⁹ and R ¹⁰ may be an ether bond formed by bonding to a carbon atom in X ₂ , and when X ₃ is a divalent hydrocarbon group, R ¹⁶ and R ¹⁷ are bonded to a carbon atom in X _3. A and b are 0 <a ≦ 1.0 and 0 ≦ b <1.0, but when R ¹ does not have a fluorine atom, 0 <a <1.0, 0 <b <1.0. c is an integer of 1 ≦ c ≦ 6, when c is 2 or more, the number of c hydrogen atoms in R ⁴ R ³ are substituted. g, h, i, j, k, l, m, and n are 1 or 2. )   The novolak resin having a repeating unit represented by the general formula (2) is a condensate of an aldehyde derivative having no fluorine atom and a substituted or unsubstituted bisnaphthol derivative having no fluorine atom. The resist underlayer film material according to claim 1.   The resist underlayer film material is represented by the acrylonitrile polymer having the repeating unit represented by the general formula (1), the novolak resin having the repeating unit represented by the general formula (2), and the general formula (3). The resist underlayer film material according to claim 1 or 2, which contains a bisnaphthol derivative.   The resist underlayer film material is composed of a novolak resin having a repeating unit represented by the general formula (2) and the general formula (1) with respect to 1 part by mass of the acrylonitrile polymer having a repeating unit represented by the general formula (1). The resist underlayer film material according to claim 3, which contains a total of 5 to 100 parts by mass of the bisnaphthol derivative represented by 3).   The resist underlayer film material according to any one of claims 1 to 4, wherein the resist underlayer film material further contains an organic solvent.   The resist underlayer film material according to any one of claims 1 to 5, wherein the resist underlayer film material further contains an acid generator and / or a crosslinking agent.   A method for forming a pattern on a substrate by lithography, wherein a resist underlayer film is formed on a substrate to be processed using the resist underlayer film material according to any one of claims 1 to 6, and the resist underlayer A silicon-containing intermediate layer film is formed on the film using a silicon-containing intermediate layer film material, a resist upper layer film is formed on the silicon-containing intermediate layer film using a resist upper layer film material, and the resist upper layer film pattern circuit After exposing the region, development is performed to form a resist pattern on the resist upper layer film, and the resist upper layer film on which the resist pattern is formed is used as a mask to transfer the pattern to the silicon-containing intermediate layer film by etching. Using the silicon-containing intermediate layer film transferred with a mask as a mask, a pattern is transferred to the resist underlayer film by etching, and further, the resist underlayer film to which the pattern is transferred Pattern forming method, characterized in that as a mask to form a pattern by etching the substrate to be processed.   A method for forming a pattern on a substrate by lithography, wherein a resist underlayer film is formed on a substrate to be processed using the resist underlayer film material according to any one of claims 1 to 6, and the resist underlayer An inorganic hard film selected from a silicon oxide film, silicon nitride film, silicon oxynitride film, silicon carbide film, polysilicon film, titanium nitride film, titanium oxide film, titanium carbide film, zirconium oxide film, or hafnium oxide film on the film Forming a mask intermediate layer film, forming a resist upper layer film on the inorganic hard mask intermediate layer film using a resist upper layer film material, exposing a pattern circuit region of the resist upper layer film, and developing the resist upper layer film; A resist pattern is formed on the film, and the resist upper layer film on which the resist pattern is formed is used as a mask to etch the inorganic hard mask intermediate film. The pattern is transferred by etching to the resist underlayer film using the inorganic hard mask intermediate layer film to which the pattern is transferred as a mask, and the resist underlayer film to which the pattern is transferred is used as a mask. A pattern forming method, wherein a pattern is formed by etching on a substrate to be processed.   A method for forming a pattern on a substrate by lithography, wherein a resist underlayer film is formed on a substrate to be processed using the resist underlayer film material according to any one of claims 1 to 6, and the resist underlayer An inorganic hard film selected from a silicon oxide film, silicon nitride film, silicon oxynitride film, silicon carbide film, polysilicon film, titanium nitride film, titanium oxide film, titanium carbide film, zirconium oxide film, or hafnium oxide film on the film A mask intermediate layer film is formed, an organic antireflection film is formed on the inorganic hard mask intermediate layer film, and a resist upper layer film is formed on the organic antireflection film using a resist upper layer film material to form a four-layer resist film The pattern circuit region of the resist upper layer film is exposed and developed to form a resist pattern on the resist upper layer film, and the resist pattern is formed on the resist pattern. Using the upper layer film as a mask, the pattern is transferred by etching to the organic antireflection film and the inorganic hard mask intermediate layer film, and the pattern is etched to the resist lower layer film using the inorganic hard mask intermediate layer film to which the pattern is transferred as a mask. And a pattern is formed on the substrate by etching using the resist underlayer film to which the pattern is transferred as a mask.   A method for forming a pattern on a substrate by lithography, wherein a resist underlayer film is formed on a substrate to be processed using the resist underlayer film material according to any one of claims 1 to 6, and the resist underlayer An inorganic hard film selected from a silicon oxide film, silicon nitride film, silicon oxynitride film, silicon carbide film, polysilicon film, titanium nitride film, titanium oxide film, titanium carbide film, zirconium oxide film, or hafnium oxide film on the film A mask interlayer film is formed, a hydrocarbon film material is formed on the inorganic hard mask interlayer film by spin coating, and a silicon-containing interlayer film material is used on the hydrocarbon film to form silicon. And forming a resist upper layer film using the resist upper layer film material on the silicon-containing intermediate layer film to form a five-layer resist film, and a pattern circuit region of the resist upper layer film After exposure, development is performed to form a resist pattern on the resist upper layer film, and the resist upper layer film on which the resist pattern is formed is used as a mask to transfer the pattern to the silicon-containing intermediate layer film by etching. The silicon-containing intermediate layer film is used as a mask to transfer a pattern to the hydrocarbon film by etching, and the hydrocarbon film to which the pattern is transferred is used as an etching mask to form a pattern on the inorganic hard mask intermediate layer film by etching. The pattern is transferred by etching to the resist underlayer film using the inorganic hard mask intermediate layer film to which the pattern is transferred as a mask, and the resist underlayer film to which the pattern is transferred is used as a mask to transfer the pattern. A pattern forming method comprising forming a pattern on a processed substrate by etching.   The pattern formation method according to claim 7, wherein the inorganic hard mask intermediate layer film is formed by any one of a CVD method, an ALD method, and a sputtering method.   Etching of the resist underlayer film using the resist upper layer film material not containing a polymer containing silicon atoms, and using the silicon-containing intermediate layer film or the inorganic hard mask intermediate layer film as a mask, The pattern forming method according to claim 7, wherein the pattern forming method is performed using an etching gas containing oxygen gas or hydrogen gas.

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