JP4388429B2 - Resist underlayer film material and pattern forming method - Google Patents

Description

The present invention relates to a resist underlayer film material that is effective as an antireflection film material used for microfabrication in a manufacturing process of a semiconductor element or the like, and in particular, far ultraviolet light, KrF excimer laser light (248 nm), ArF excimer laser light (193 nm), The present invention relates to a resist underlayer film material of a multilayer resist film suitable for exposure with F ₂ laser light (157 nm), Kr ₂ laser light (146 nm), Ar ₂ laser light (126 nm), or the like. Furthermore, this invention relates to the method of forming a pattern in a board | substrate by lithography using this.

  In recent years, with the increasing integration and speed of LSIs, there is a need for finer pattern rules. In lithography using light exposure, which is currently used as a general-purpose technology, the essence derived from the wavelength of the light source The resolution limit is approaching.

  As a light source for lithography used in forming a resist pattern, light exposure using a g-ray (436 nm) or i-line (365 nm) of a mercury lamp as a light source is widely used, but as a means for further miniaturization. A method of shortening the wavelength of exposure light has been considered effective. For this reason, for example, in a mass production process of a 64-Mbit DRAM processing method, a short wavelength KrF excimer laser (248 nm) is used as an exposure light source instead of i-line (365 nm). However, in order to manufacture a DRAM having a degree of integration of 1G or more, which requires a finer processing technique (for example, a processing dimension of 0.13 μm or less), a light source with a shorter wavelength is required, particularly an ArF excimer laser (193 nm). Lithography using a material has been studied.

  On the other hand, it is conventionally known that a multilayer resist process such as a two-layer resist process is excellent for forming a pattern with a high aspect ratio on a stepped substrate. In the two-layer resist process, in order to develop the two-layer resist film with a general alkaline developer, it is preferable to use a high molecular silicone compound having a hydrophilic group such as a hydroxy group or a carboxyl group as the resist upper layer film. It is said that.

As such a high molecular silicone compound, a base resin in which a part of the phenolic hydroxyl group of polyhydroxybenzylsilsesquioxane, which is a stable alkali-soluble silicone polymer, is protected with a t-Boc group is used for a KrF excimer laser. A silicone-based chemically amplified positive resist material that is used in combination with an acid generator has been proposed (see, for example, Patent Document 1 and Non-Patent Document 1). For ArF excimer lasers, positive resists based on silsesquioxane of a type in which cyclohexyl carboxylic acid is substituted with an acid labile group have been proposed (for example, Patent Document 2, Patent Document 3, Non-Patent Document 3, (See Patent Document 2). Furthermore, for F ₂ lasers, positive resists based on silsesquioxane having hexafluoroisopropanol as a soluble group have been proposed (for example, see Patent Document 4). The polymer contains a polysilsesquioxane having a ladder skeleton formed by condensation polymerization of trialkoxysilane or trihalogenated silane in the main chain.

  As a high molecular silicone compound in which silicon is pendant on a side chain, a silicon-containing (meth) acrylic ester-based polymer has been proposed (see, for example, Patent Document 5 and Non-Patent Document 3).

  As the resist underlayer film used in the two-layer resist process, for example, a hydrocarbon compound that can be etched with oxygen gas, and the like can be used. Further, since it serves as a mask when etching the substrate underneath, high etching is performed during substrate etching. It is desirable to have resistance. When the etching of the resist lower layer film using the resist upper layer film as a mask is based on oxygen gas etching, the resist lower layer film is preferably composed only of hydrocarbons not containing silicon atoms. In addition, in order to improve the line width controllability of the resist upper layer film containing silicon atoms and to reduce the pattern sidewall irregularities and pattern collapse due to standing waves, the resist underlayer film also functions as an antireflection film. Specifically, it is desirable that the reflectance from the resist lower layer film into the resist upper layer film can be suppressed to 1% or less.

  By the way, the base antireflection film for the single layer resist process is made of a material having an optimum refractive index (n value) and extinction coefficient (k value) even when the underlying substrate is a highly reflective substrate such as polysilicon or aluminum. By setting the film thickness to an appropriate thickness, the reflection from the substrate can be reduced to 1% or less, and an extremely large antireflection effect can be exhibited.

  FIG. 1 is a graph showing the relationship between the film thickness and reflectance of a base antireflection film for a single layer resist process at a wavelength of 193 nm. From FIG. 1, for example, at a wavelength of 193 nm, the refractive index of the resist film is 1.7, the refractive index (real part of the refractive index) n of the underlying antireflection film is 1.5, and the extinction coefficient (imaginary number of refractive index). Part) When k is 0.5 and the film thickness is 42 nm, it can be seen that the reflectance is 0.5% or less.

  However, when there is a step in the base substrate, the film thickness of the antireflection film varies greatly on the step. As can be seen from FIG. 1, the antireflection effect of the base antireflection film not only absorbs light but also uses an interference effect by setting an optimum film thickness, so that the interference effect is strong. The first bottom of 45 nm also has a high antireflection effect, but the reflectivity varies greatly with the change in film thickness.

  Thus, a material has been proposed in which the molecular weight of the base resin used for the antireflection film material is increased to suppress the film thickness fluctuation on the step and to improve the conformality (for example, see Patent Document 6). However, in this case, if the molecular weight of the base resin is high, problems such as pinholes are likely to occur after spin coating, filtration is impossible, and the film thickness changes due to changes in viscosity over time. In addition, there arises a problem that crystals are deposited at the tip of the nozzle. In addition, conformal properties can be exhibited only at steps having a relatively low height.

  Then, from FIG. 1, a method of adopting a film thickness (170 nm or more) of the third base or more in which the change in reflectance due to the film thickness change is relatively small can be considered. In this case, if the k value of the antireflection film is between 0.2 and 0.3 and the film thickness is 170 nm or more, the change in the reflectivity with respect to the change in the film thickness is small, and the reflectivity is 1.5%. It is known that the following can be suppressed. However, considering the etching load of the resist film thereon, there is a limit to increasing the thickness of the antireflection film, and it is limiting to increase the thickness of the second bottom side of about 100 nm or less.

  When the base of the antireflection film is a transparent film such as an oxide film or a nitride film, and there is a step under the transparent film, the surface of the transparent film is flattened by CMP (Chemical Mechanical Polishing) or the like. Even if the thickness is changed, the thickness of the transparent film varies. In this case, it is possible to make the film thickness of the antireflection film constant on the film, but when the film thickness of the transparent film under the antireflection film varies, the film thickness that provides the minimum reflectance is the film of the transparent film. It will shift by the thickness. Even when the film thickness of the antireflection film is set to a film thickness that provides the minimum reflectance when the base is a reflection film, the reflectance may increase due to a change in the film thickness of the transparent film.

Such antireflection film materials can be broadly classified into inorganic and organic materials.
An inorganic system is a SiON film. This is formed by CVD (Chemical Vapor Deposition) using a mixed gas of silane and ammonia and has a large etching selection ratio with respect to the resist film. However, there are limitations when applicable. In addition, since it is a basic substrate containing nitrogen atoms, there is a drawback that it tends to have a footing in a positive resist and an undercut profile in a negative resist.

  Organic systems can be spin-coated and do not require special equipment such as CVD or sputtering, can be peeled off simultaneously with the resist film, have no tailing, have a straight shape, and adhere to the resist film The anti-reflection film based on many organic materials has been proposed. For example, a condensate of a diphenylamine derivative and a formaldehyde-modified melamine resin, an alkali-soluble resin and a light absorber (see, for example, Patent Document 7), a reaction product of a maleic anhydride copolymer and a diamine type light absorber ( For example, see Patent Document 8), an acrylic resin base containing a resin binder and a methylolmelamine-based thermal crosslinking agent (see, for example, Patent Document 9), a carboxylic acid group, an epoxy group, and a light-absorbing group in the same molecule. Type (for example, see Patent Document 10), one comprising methylol melamine and a benzophenone-based light absorber (for example, see Patent Document 11), or one obtained by adding a low molecular light absorber to a polyvinyl alcohol resin (for example, see Patent Document 12). Etc.). Antireflection films based on all these organic materials employ a method in which a light absorber is added to the binder polymer or introduced as a substituent into the polymer. However, since many of the light-absorbing agents have aromatic groups or double bonds, the addition of the light-absorbing agent increases the resistance to dry etching and has a drawback that the dry etching selectivity with the resist film is not so high. Since the miniaturization has progressed and the thinning of the resist film has been spurred, and in the next-generation ArF exposure, an acrylic or alicyclic polymer is used as the resist film material, so the resist film is etched. Resistance is reduced. Further, as described above, there is a problem that the thickness of the antireflection film must be increased. For this reason, etching is a serious problem, and an antireflection film having a high etching selectivity relative to a resist film, that is, a high etching speed is required.

  On the other hand, the function required as an antireflection film in the resist underlayer film for the two-layer resist process is different from that of the antireflection film for the single-layer resist process. Since the resist underlayer film for the two-layer resist process serves as a mask for etching the substrate, it must have high etching resistance under the substrate etching conditions. As described above, the antireflection film in the single-layer resist process is required to have a high etching rate in order to lighten the etching load of the single-layer resist film, whereas the reverse characteristics are required. In addition, in order to ensure sufficient etching resistance during substrate etching, the thickness of the resist underlayer film must be increased to about 300 nm, which is equal to or higher than that of the single-layer resist film. However, when the film thickness is 300 nm or more, the change in reflectance due to the change in film thickness almost converges, and the antireflection effect by phase difference control cannot be expected.

Here, the results of calculating the substrate reflectivity when the thickness of the resist underlayer film is varied in the range of 0 to 500 nm are shown in FIGS. It is assumed that the exposure wavelength is 193 nm, the n value of the resist upper layer film is 1.74, and the k value is 0.02.
In FIG. 2, the k value of the resist underlayer film is fixed at 0.3, the vertical axis is the n value, the horizontal axis is the film thickness, the n value is in the range of 1.0 to 2.0, and the film thickness is 0 to 500 nm. The substrate reflectivity when it is varied in the range is shown. Referring to FIG. 2, assuming a resist underlayer film for a two-layer resist process having a film thickness of 300 nm or more, the n value is about 1.6 to 1.9 which is the same as or slightly higher than the resist upper layer film. It can be seen that there exists an optimum value that can reduce the reflectance to 1% or less in the range of.

  In FIG. 3, the n value of the resist underlayer film is fixed to 1.5, the vertical axis is the k value, the horizontal axis is the film thickness, the k value is in the range of 0.1 to 0.8, and the film thickness is 0 to The reflectivity when varied in the range of 500 nm is shown. Referring to FIG. 3, assuming a resist underlayer film for a two-layer resist process having a film thickness of 300 nm or more, the reflectance may be reduced to approximately 1% or less in the range of k value from 0.24 to 0.15. It turns out that it is possible. On the other hand, the optimum k value of an antireflection film for a single layer resist process used for a thin film of about 40 nm is 0.4 to 0.5, and what is the optimum k value of a resist underlayer film for a two layer resist process of 300 nm or more. Different. Thus, it is shown that the resist underlayer film for a two-layer resist process needs to have a lower k value, that is, a higher transparency.

  Therefore, a polyhydroxystyrene / acrylic copolymer has been studied as a resist underlayer film material for a wavelength of 193 nm (for example, see Non-Patent Document 4). Polyhydroxystyrene has very strong absorption at a wavelength of 193 nm, and the k value itself is a high value of around 0.6. Therefore, the k value is adjusted to around 0.25 by copolymerizing with acrylic whose k value is almost zero.

  However, with respect to polyhydroxystyrene, the etching resistance in acrylic substrate etching is weak, and in order to lower the k value, a considerable proportion of acrylic must be copolymerized. As a result, the etching resistance during substrate etching is low. It drops considerably. Etching resistance appears not only in the etching rate but also in the occurrence of surface roughness after etching. The increase in surface roughness after etching becomes more prominent as a result of acrylic copolymerization.

Therefore, a naphthalene ring is one of those having higher transparency at a wavelength of 193 nm and higher etching resistance than a benzene ring, and it has been proposed to use this. For example, a resist underlayer film having a naphthalene ring or an anthracene ring has been proposed (see, for example, Patent Document 13). However, the k value of naphthol co-condensed novolak resin and polyvinyl naphthalene resin is between 0.3 and 0.4, and the target transparency of 0.1 to 0.3 is not achieved, and the desired antireflection In order to obtain the effect, the transparency must be further increased. In addition, the n value at a wavelength of 193 nm of the naphthol co-condensed novolak resin and the polyvinyl naphthalene resin is low, and as a result of measurement by the present inventors, it is 1.4 for the naphthol co-condensed novolak resin and 1.2 for the polyvinyl naphthalene resin. Yes, the target range has not been achieved. Furthermore, although an acenaphthylene polymer has been proposed (see, for example, Patent Document 14 and Patent Document 15), this has a lower n value at a wavelength of 193 nm than that of a wavelength of 248 nm, a higher k value, and both reach the target value. Not.
Thus, there is a demand for a resist underlayer film having a high n value, a low k value, and transparency and high etching resistance.

JP-A-6-118651 Japanese Patent Laid-Open No. 10-324748 JP-A-11-302382 JP 2002-55456 A JP-A-9-110938 Japanese Patent Laid-Open No. 10-69072 Japanese Patent Publication No. 7-69611 US Pat. No. 5,294,680 Japanese Patent Laid-Open No. 6-118631 JP-A-6-118656 JP-A-8-87115 JP-A-8-179509 JP 2002-14474 A JP 2001-40293 A JP 2002-214777 A SPIE vol. 1925 (1993) p377 SPIE vol. 3333 (1998) p62 J. et al. Photopolymer Sci. and Technol. Vol. 9 No. 3 (1996) p435-446 SPIE Vol. 4345 p50 (2001)

  The present invention has been made in view of such problems, and is a resist underlayer film material for a multilayer resist process, for example, a resist upper layer film containing silicon, particularly for a two-layer resist process. It functions as an excellent anti-reflection film for wavelength exposure, that is, it is more transparent than polyhydroxystyrene, cresol novolak, naphthol novolak, etc., and has optimal n and k values, and etching in substrate processing An object of the present invention is to provide a resist underlayer film material having excellent resistance and a method of forming a pattern on a substrate by lithography using the resist underlayer film material.

The present invention has been made to solve the above problems, and is a resist underlayer film material for a multilayer resist film used in lithography, which has at least a repeating unit of acenaphthylenes and a substituted or unsubstituted hydroxy group. that provides a resist underlayer film material characterized by a repeating unit is intended to include copolymerized formed by polymer.

（上記一般式（１）中、Ｒ^１は、水素原子又はメチル基である。Ｒ^２は、単結合、炭素数１〜２０の直鎖状、分岐状、環状のアルキレン基、炭素数６〜１０のアリーレン基のいずれかであり、エーテル、エステル、ラクトン、アミドのいずれかを有していてもよい。Ｒ^３、Ｒ^４は、それぞれ、水素原子又はグリシジル基である。Ｘは、インデン骨格を含む炭化水素、炭素数３〜１０のシクロオレフィン、マレイミドのいずれかの重合体を示し、エーテル、エステル、ラクトン、カルボン酸無水物のいずれかを有していてよい。Ｒ^５、Ｒ^６は、それぞれ、水素原子、フッ素原子、メチル基、トリフルオロメチル基のいずれかである。Ｒ^７は、水素原子、炭素数１〜６の直鎖状、分岐状、環状のアルキル基、ヒドロキシ基、アルコキシカルボニル基のいずれかである。ｐ、ｑは、それぞれ１〜４の整数である。ｒは、０〜４の整数である。ａ，ｂ，ｃは、それぞれ０．５≦ａ＋ｂ＋ｃ≦１、０≦ａ≦０．８、０≦ｂ≦０．８、０．１≦ａ＋ｂ≦０．８、０．１≦ｃ≦０．８の範囲である。） In this case, the polymer is not the preferred of those having a repeating unit represented by the following general formula (1).

(In the general formula (1), R ¹ is a hydrogen atom or a methyl group. R ² is a single bond, a linear, branched or cyclic alkylene group having 1 to 20 carbon atoms, or 6 to 6 carbon atoms. Any one of 10 arylene groups, which may have any of ether, ester, lactone and amide, wherein R ³ and R ⁴ are each a hydrogen atom or a glycidyl group, and X is an indene skeleton R ⁵ , R ⁶ may be any one of ether, ester, lactone, and carboxylic acid anhydride, and may be any one of a hydrocarbon, a C 3-10 cycloolefin, and a maleimide. Are each a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, and R ⁷ is a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, a hydroxy group, Alkoxycal P and q are each an integer of 1 to 4. r is an integer of 0 to 4. a, b, and c are 0.5 ≦ a + b + c ≦ 1, 0, respectively. ≦ a ≦ 0.8, 0 ≦ b ≦ 0.8, 0.1 ≦ a + b ≦ 0.8, 0.1 ≦ c ≦ 0.8.

  Thus, a polymer obtained by copolymerizing a repeating unit of acenaphthylenes and a repeating unit having a substituted or unsubstituted hydroxy group, particularly a polymer having a repeating unit represented by the general formula (1) above. The resist underlayer film material that is included functions as an excellent antireflection film, particularly for exposure at a short wavelength, that is, has high transparency, has an optimal n value, k value, and etching resistance during substrate processing. It is excellent.

Then, a resist underlayer film material of the present invention, furthermore organic solvents, acid generators, have the preferred to contain any one or more ones of the cross-linking agent.

  Thus, the resist underlayer film material of the present invention further contains any one or more of an organic solvent, a crosslinking agent, and an acid generator, thereby improving the applicability of the material to a substrate or the like. The crosslinking reaction in the resist underlayer film can be promoted by baking or after applying to the substrate or the like. Therefore, such a resist underlayer film has good film thickness uniformity, is less likely to be intermixed with the resist upper layer film, and has low diffusion of low molecular components into the resist upper layer film.

Furthermore, the present invention is a method of forming a pattern on a substrate by lithography, wherein at least a resist underlayer film is formed on the substrate using the resist underlayer film material of the present invention, and a photoresist is formed on the underlayer film. The resist upper layer film of the composition is formed to form a multilayer resist film, the pattern circuit region of the multilayer resist film is exposed, and then developed with a developing solution to form a resist pattern on the resist upper layer film. A pattern forming method is provided, in which a resist underlayer film is etched using a resist upper layer film as a mask, and a substrate is etched using a multilayer resist film having a pattern formed as a mask to form a pattern on the substrate. The

  Thus, if a pattern is formed by lithography using the resist underlayer film material of the present invention, the pattern can be formed on the substrate with high accuracy.

Examples resist upper layer film, using a material obtained by containing a silicon atom, the resist etching of the upper film using the resist underlayer film as a mask, has the preferred to carry out the oxygen gas in the dry etching mainly.

  As described above, the resist underlayer film formed using the resist underlayer film material of the present invention uses a silicon atom-containing resist upper layer film, and etching of the lower layer film using the resist upper layer film as a mask is performed using oxygen gas. It is particularly suitable for forming a pattern by performing dry etching mainly composed of. Therefore, if the substrate is etched using the multilayer resist film as a mask and a pattern is formed on the substrate, a highly accurate pattern can be formed.

In this case, the etching of the substrate in which the multi-layer resist film on which the pattern is formed on the mask, flon gas, chlorine gas, Ru can either bromine-based gas carried by dry etching mainly.

  The resist underlayer film formed by using the resist underlayer film material of the present invention is particularly excellent in etching resistance against dry etching mainly composed of any one of a fluorocarbon gas, a chlorine gas, and a bromine gas. Therefore, if the substrate is etched using this multilayer resist film as a mask, a pattern with high accuracy can be obtained by forming a pattern on the substrate by dry etching mainly using any of a fluorocarbon gas, a chlorine gas, or a bromine gas. Can be formed.

  As described above, according to the present invention, for example, a resist underlayer film material for a multi-layer resist process such as one in which the resist upper layer film contains silicon, particularly for a two-layer resist process, particularly for exposure at a short wavelength. On the other hand, it functions as an excellent antireflection film, that is, it is more transparent than polyhydroxystyrene, cresol novolak, naphthol novolak, etc., and has an optimal n value (refractive index) and k value (quenching coefficient). A resist underlayer film material having excellent etching resistance in substrate processing can be obtained.

Hereinafter, the best mode for carrying out the present invention will be described, but the present invention is not limited thereto.
As a result of intensive studies to achieve the above object, the present inventors have obtained a polymer obtained by copolymerizing a repeating unit of acenaphthylenes and a repeating unit having a substituted or unsubstituted hydroxy group, for example, It has been found that it is a promising material as a resist underlayer film for a multilayer resist process such as a silicon-containing two-layer resist process, having an optimum n value and k value in exposure at a short wavelength such as 193 nm and excellent etching resistance. The present invention has been made.

  That is, the resist underlayer film material of the present invention is a resist underlayer film material of a multilayer resist film used in lithography, and includes at least a repeating unit of acenaphthylenes and a repeating unit having a substituted or unsubstituted hydroxy group. It is characterized by containing a polymer obtained by polymerization.

（上記一般式（１）中、Ｒ^１は、水素原子又はメチル基である。Ｒ^２は、単結合、炭素数１〜２０の直鎖状、分岐状、環状のアルキレン基、炭素数６〜１０のアリーレン基のいずれかであり、エーテル、エステル、ラクトン、アミドのいずれかを有していてもよい。Ｒ^３、Ｒ^４は、それぞれ、水素原子又はグリシジル基である。Ｘは、インデン骨格を含む炭化水素、炭素数３〜１０のシクロオレフィン、マレイミドのいずれかの重合体を示し、エーテル、エステル、ラクトン、カルボン酸無水物のいずれかを有していてよい。Ｒ^５、Ｒ^６は、それぞれ、水素原子、フッ素原子、メチル基、トリフルオロメチル基のいずれかである。Ｒ^７は、水素原子、炭素数１〜６の直鎖状、分岐状、環状のアルキル基、ヒドロキシ基、アルコキシカルボニル基のいずれかである。ｐ、ｑは、それぞれ１〜４の整数である。ｒは、０〜４の整数である。ａ，ｂ，ｃは、それぞれ０．５≦ａ＋ｂ＋ｃ≦１、０≦ａ≦０．８、０≦ｂ≦０．８、０．１≦ａ＋ｂ≦０．８、０．１≦ｃ≦０．８の範囲である。） In this case, the polymer preferably has a repeating unit represented by the following general formula (1).

(In the general formula (1), R ¹ is a hydrogen atom or a methyl group. R ² is a single bond, a linear, branched or cyclic alkylene group having 1 to 20 carbon atoms, or 6 to 6 carbon atoms. Any one of 10 arylene groups, which may have any of ether, ester, lactone and amide, wherein R ³ and R ⁴ are each a hydrogen atom or a glycidyl group, and X is an indene skeleton R ⁵ , R ⁶ may be any one of ether, ester, lactone, and carboxylic acid anhydride, and may be any one of a hydrocarbon, a C 3-10 cycloolefin, and a maleimide. Are each a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, and R ⁷ is a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, a hydroxy group, Alkoxycal P and q are each an integer of 1 to 4. r is an integer of 0 to 4. a, b, and c are 0.5 ≦ a + b + c ≦ 1, 0, respectively. ≦ a ≦ 0.8, 0 ≦ b ≦ 0.8, 0.1 ≦ a + b ≦ 0.8, 0.1 ≦ c ≦ 0.8.

  The resist underlayer film formed from the resist underlayer film material of the present invention is a novel resist underlayer film applicable to a multilayer resist process such as a silicon-containing two-layer resist process and a three-layer resist process having a silicon-containing intermediate layer. . In particular, when exposure is performed at a short wavelength such as 193 nm, the antireflection effect is excellent when the film thickness is 200 nm or more, and the etching resistance under substrate etching conditions is excellent.

  Further, by adding any one or more of an organic solvent, a crosslinking agent, and an acid generator to the resist underlayer film material, it is possible to improve the coating property of the material on the substrate or the like. The crosslinking reaction in the resist underlayer film can be promoted by baking or the like after coating. Therefore, such a resist underlayer film has good film thickness uniformity, is less likely to be intermixed with the resist upper layer film, and has low diffusion of low molecular components into the resist upper layer film.

  Here, as a repeating unit in the polymer contained in the resist underlayer film material of the present invention, a repeating unit having a substituted or unsubstituted hydroxy group, particularly the repeating units a and b represented by the general formula (1) Specifically, it can be exemplified below.

  The monomer for obtaining the repeating units a and b represented by the general formula (1) has an ethylenically unsaturated bond, and the hydroxy group is an acetyl group, a formyl group, a pivaloyl group, an acetal group, trimethylsilyl during polymerization. It may be substituted with a group or the like.

  The resist underlayer film material of the present invention is based on a polymer obtained by copolymerizing a repeating unit of acenaphthylenes and a repeating unit having a substituted or unsubstituted hydroxy group, but is copolymerized with other monomers. Can also be used. Examples of copolymerizable monomers include styrene, indene, indole, methyleneindane, (meth) acryl derivatives, norbornadiene derivatives, norbornene derivatives, maleic anhydride, maleimide derivatives, vinyl naphthalene derivatives, vinyl anthracene derivatives, vinyl ether derivatives, allyl ether derivatives. , (Meth) acrylonitrile, vinyl pyrrolidone, tetrafluoroethylene, etc. may be mentioned, and a ternary or higher copolymer containing these may be used.

In order to synthesize the polymer contained in the resist underlayer film material of the present invention, one method is to perform polymerization by adding acenaphthylene and a hydroxyl group-containing monomer in an organic solvent and adding a radical initiator or a cationic polymerization initiator. . The hydroxy group of the monomer containing a hydroxy group can be substituted with an acetyl group, and the resulting polymer compound can be subjected to alkaline hydrolysis in an organic solvent to deprotect the acetyl group. Moreover, after copolymerizing with the monomer which has acenaphthylene and a glycidyl ether group, an epoxy ring can be opened by hydrolysis and it can also be set as alcohol. Examples of the organic solvent used at the time of polymerization include toluene, benzene, tetrahydrofuran, diethyl ether, dioxane and the like. Examples of radical polymerization initiators include 2,2′-azobisisobutyronitrile (AIBN), 2,2′-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2-azobis (2-methylpropio). Nate), benzoyl peroxide, lauroyl peroxide, and the like, preferably polymerized by heating from 50 ° C to 80 ° C. Examples of the cationic polymerization initiator include sulfuric acid, phosphoric acid, hydrochloric acid, nitric acid, hypochlorous acid, trichloroacetic acid, trifluoroacetic acid, methanesulfonic acid, trifluoromethanesulfonic acid, camphorsulfonic acid, tosylic acid and the like, BF ₃ , AlCl _3, TiCl _4, SnCl ₄ other Friedel-Crafts catalyst such _{as, I 2, (C 6 H} 5) 3 generated material susceptible to cationic as CCl are used.

  The reaction time is 2 to 100 hours, preferably 5 to 20 hours. Ammonia water, triethylamine, etc. can be used as the base during the alkali hydrolysis. The reaction temperature is −20 to 100 ° C., preferably 0 to 60 ° C., and the reaction time is 0.2 to 100 hours, preferably 0.5 to 20 hours.

  The mass average molecular weight is preferably in the range of 1,500 to 200,000, more preferably in the range of 2,000 to 100,000. The molecular weight distribution is not particularly limited, and low molecular weight and high molecular weight substances can be removed by fractionation to reduce the degree of dispersion. The weight of two or more general formulas (1) having different molecular weights and degrees of dispersion can be reduced. Mixtures of blends or two or more polymers of the general formula (1) having different composition ratios may be mixed.

  In order to further improve the transparency of the polymer contained in the resist underlayer film material of the present invention, particularly the polymer having a repeating unit represented by the general formula (1) at a wavelength of 193 nm, hydrogenation can be performed. A preferable hydrogenation ratio is 80 mol% or less, more preferably 60 mol% or less of the aromatic group.

  The base resin for the resist underlayer film material of the present invention includes a polymer obtained by copolymerizing a repeating unit of acenaphthylenes and a repeating unit having a substituted or unsubstituted hydroxy group. It can also be blended with conventional polymers mentioned as antireflective coating materials. Polyacenaphthylene has a glass transition point of 150 ° C. or higher, and this alone may have poor deep hole filling characteristics such as via holes. In order to embed holes without generating voids, a technique is employed in which a polymer having a low glass transition point is used and a resin is embedded to the bottom of the hole while heat-flowing at a temperature lower than the crosslinking temperature (for example, JP 2000-294504 gazette.) Polymers having a low glass transition point, especially polymers having a glass transition point of 180 ° C. or lower, particularly 100 to 170 ° C., such as acrylic derivatives, vinyl alcohol, vinyl ethers, allyl ethers, styrene derivatives, allylbenzene derivatives, ethylene, propylene, butadiene By blending with one or two or more types of copolymer selected from olefins such as metathesis ring-opening polymerization, the glass transition point can be lowered, and the via hole embedding property can be improved.

  One of the performances required for the resist underlayer film is that there is no intermixing with the resist upper layer film and that there is no diffusion of low molecular components into the resist upper layer film (for example, “Proc. SPIE Vol. 2195”). P225-229 (1994) ". In order to prevent these problems, a method is generally employed in which a resist underlayer film is formed on a substrate by spin coating or the like and then thermally crosslinked by baking. Therefore, when a crosslinking agent is added as a component of the resist underlayer film material, a crosslinkable substituent may be introduced into the polymer.

  Specific examples of the crosslinking agent that can be used in the present invention include a melamine compound, a guanamine compound, a glycoluril compound, or a urea compound substituted with at least one group selected from a methylol group, an alkoxymethyl group, and an acyloxymethyl group. Examples include compounds containing double bonds such as epoxy compounds, isocyanate compounds, azide compounds, and alkenyl ether groups. 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 specific examples of the crosslinking agent, when an epoxy compound is further exemplified, tris (2,3-epoxypropyl) isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, triethylolethane triglycidyl ether, and the like. Illustrated. Specific examples of the melamine compound include hexamethylol melamine, hexamethoxymethyl melamine, a compound in which 1 to 6 methylol groups of hexamethylol melamine are methoxymethylated, and a mixture thereof, hexamethoxyethyl melamine, hexaacyloxymethyl melamine, Examples thereof include compounds in which 1 to 6 methylol groups of hexamethylolmelamine are acyloxymethylated, or a mixture thereof. Examples of the guanamine compound include tetramethylolguanamine, tetramethoxymethylguanamine, a compound in which 1 to 4 methylol groups of tetramethylolguanamine are methoxymethylated, and a mixture thereof, tetramethoxyethylguanamine, tetraacyloxyguanamine, and tetramethylolguanamine. Examples include compounds in which 4 methylol groups are acyloxymethylated and mixtures thereof. Examples of the glycoluril compound include tetramethylol glycoluril, tetramethoxyglycoluril, tetramethoxymethylglycoluril, a compound in which 1 to 4 of the methylol groups of tetramethylolglycoluril are methoxymethylated, or a mixture thereof, tetramethylolglycoluril Or a mixture thereof in which 1 to 4 of the methylol groups are acyloxymethylated. Examples of the urea compound include tetramethylol urea, tetramethoxymethyl urea, a compound in which 1 to 4 methylol groups of tetramethylol urea are methoxymethylated, or 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.

  Examples of the compound containing an alkenyl ether group include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,4-butanediol divinyl ether, tetramethylene glycol divinyl ether, neopentyl glycol divinyl ether, Examples include trimethylolpropane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, and trimethylolpropane trivinyl ether.

When the hydroxy group of the polymer contained in the resist underlayer film material of the present invention, for example, the polymer having a repeating unit represented by the general formula (1) is substituted with a glycidyl group, addition of a compound containing a hydroxy group It is valid. Particularly preferred are compounds containing two or more hydroxy groups in the molecule. Examples of the compound containing a hydroxy group include naphthol novolak, m- and p-cresol novolak, naphthol-dicyclopentadiene novolak, m- and p-cresol-dicyclopentadiene novolak, 4,8-bis (hydroxymethyl) tricyclo. [5.2.1.0 ^2,6 ] -decane, pentaerythritol, 1,2,6-hexanetriol, 4,4 ′, 4 ″ -methylidenetriscyclohexanol, 4,4 ′-[1- [4- [1- (4-Hydroxycyclohexyl) -1-methylethyl] phenyl] ethylidene] biscyclohexanol, [1,1′-bicyclohexyl] -4,4′-diol, methylenebiscyclohexanol, decahydro Naphthalene-2,6-diol, [1,1′-bicyclohexyl] -3,3 ′, 4,4 Alcohol group-containing compounds such as '-tetrahydroxy, bisphenol, methylenebisphenol, 2,2'-methylenebis [4-methylphenol], 4,4'-methylidene-bis [2,6-dimethylphenol], 4,4' -(1-methyl-ethylidene) bis [2-methylphenol], 4,4'-cyclohexylidenebisphenol, 4,4 '-(1,3-dimethylbutylidene) bisphenol, 4,4'-(1- Methylethylidene) bis [2,6-dimethylphenol], 4,4′-oxybisphenol, 4,4′-methylenebisphenol, bis (4-hydroxyphenyl) methanone, 4,4′-methylenebis [2-methylphenol ], 4,4 '-[1,4-phenylenebis (1-methylethylidene)] bisphenol, 4,4'-(1,2 Ethanediyl) bisphenol, 4,4 ′-(diethylsilylene) bisphenol, 4,4 ′-[2,2,2-trifluoro-1- (trifluoromethyl) ethylidene] bisphenol, 4,4 ′, 4 ″- Methylidenetrisphenol, 4,4 ′-[1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] bisphenol, 2,6-bis [(2-hydroxy-5-methylphenyl) methyl]- 4-methylphenol, 4,4 ′, 4 ″ -ethylidene tris [2-methylphenol], 4,4 ′, 4 ″ -ethylidene trisphenol, 4,6-bis [(4-hydroxyphenyl) Methyl] 1,3-benzenediol, 4,4 ′-[(3,4-dihydroxyphenyl) methylene] bis [2-methylphenol], 4,4 ′, 4 ″, 4 ′ ″- 1,2-ethanediylidene) tetrakisphenol, 4,4 ′, 4 ″, 4 ′ ″-ethanediylidene) tetrakis [2-methylphenol], 2,2′-methylenebis [6-[(2-hydroxy-5- Methylphenyl) methyl] -4-methylphenol], 4,4 ′, 4 ″, 4 ′ ″-(1,4-phenylenedimethylidyne) tetrakisphenol, 2,4,6-tris (4-hydroxyphenyl) Methyl) 1,3-benzenediol, 2,4 ′, 4 ″ -methylidenetrisphenol, 4,4 ′, 4 ′ ″-(3-methyl-1-propanyl-3-ylidene) trisphenol, 2 , 6-bis [(4-hydroxy-3-fluorophenyl) methyl] -4-fluorophenol, 2,6-bis [4-hydroxy-3-fluorophenyl] methyl] -4-fluorophenol, 3,6-bis “(3,5-dimethyl-4-hydroxyphenyl) methyl” 1,2-benzenediol, 4,6-bis “(3,5-dimethyl-4-hydroxyphenyl) methyl” 1,3 Benzenediol, p-methylcalix [4] arene, 2,2′-methylenebis [6-[(2,5 / 3,6-dimethyl-4 / 2-hydroxyphenyl) methyl] -4-methylphenol, 2 , 2′-methylenebis [6-[(3,5-dimethyl-4-hydroxyphenyl) methyl] -4-methylphenol, 4,4 ′, 4 ″, 4 ′ ″-tetrakis [(1-methylethylidene ) Bis (1,4-cyclohexylidene)] phenol, 6,6'-methylenebis [4- (4-hydroxyphenylmethyl) -1,2,3-benzenetriol, 3,3 ', 5,5'- Tetrakis [ 5-methyl-2-hydroxyphenyl) methyl] - [(1,1'-biphenyl) -4,4'-diol] phenol low nuclear bodies and the like.

  The blending amount of the crosslinking agent in the resist underlayer film material of the present invention is preferably 5 to 50 parts, particularly preferably 10 to 40 parts, relative to 100 parts (parts by mass, the same applies hereinafter) of the base polymer (total resin). If it is less than 5 parts, it may cause mixing with the resist. If it exceeds 50 parts, the antireflection effect may be reduced, or cracks may occur in the crosslinked film.

  In the resist underlayer film material of the present invention, an acid generator for further promoting the crosslinking reaction by heat or the like can be added. 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.

As an acid generator used in the resist underlayer film material of the present invention,
i. An onium salt of the following general formula (P1a-1), (P1a-2), (P1a-3) or (P1b),
ii. A diazomethane derivative of the following general formula (P2):
iii. ) Glyoxime derivative of the following general formula (P3),
iv. ) Bissulfone derivatives of the following general formula (P4),
v. ) A sulfonic acid ester of an N-hydroxyimide compound of the following general formula (P5),
vi. ) Β-ketosulfonic acid derivatives,
vii. ) Disulfone derivatives,
viii. ) Nitrobenzyl sulfonate derivative,
ix. ) Sulfonic acid ester derivatives and the like.

（上記式中、Ｒ^101a、Ｒ^101b、Ｒ^101cはそれぞれ炭素数１〜１２の直鎖状、分岐状又は環状のアルキル基、アルケニル基、オキソアルキル基又はオキソアルケニル基、炭素数６〜２０のアリール基、又は炭素数７〜１２のアラルキル基又はアリールオキソアルキル基を示し、これらの基の水素原子の一部又は全部がアルコキシ基等によって置換されていてもよい。また、Ｒ^101bとＲ^101cとは環を形成してもよく、環を形成する場合には、Ｒ^101b、Ｒ^101cはそれぞれ炭素数１〜６のアルキレン基を示す。Ｋ^-は非求核性対向イオンを表す。Ｒ^101d、Ｒ^101e、Ｒ^101f、Ｒ^101gは、Ｒ^101a、Ｒ^101b、Ｒ^101cに水素原子を加えて示される。Ｒ^101dとＲ^101e、Ｒ^101dとＲ^101eとＲ^101fとは環を形成してもよく、環を形成する場合には、Ｒ^101dとＲ^101e及びＲ^101dとＲ^101eとＲ^101fは炭素数３〜１０のアルキレン基、又は図中の窒素原子を環の中に有する複素芳香族環を示す。）

(In the above formula, R ^101a , R ^101b and R ^101c are each a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, an alkenyl group, an oxoalkyl group or an oxoalkenyl group, and having 6 to 20 carbon atoms. An aryl group, an aralkyl group having 7 to 12 carbon atoms, or an aryloxoalkyl group, part or all of hydrogen atoms of which may be substituted with an alkoxy group, etc. R ^101b and R ^101c and may form a ring, when they form a ring, R ^101b, .K indicating each is R ^101c alkylene group having 1 to 6 carbon atoms ^- .R ^101d is representative of a non-nucleophilic counter ion R ^101e , R ^101f and R ^101g are represented by adding a hydrogen atom to R ^101a , R ^101b and R ^101c , R ^101d and R ^101e , and R ^101d , R ^101e and R ^101f may form a ring. Well, when forming a ring, R ^101d and R ^101e and R ^101d and R ^101e and R ^101f represent an alkylene group having 3 to 10 carbon atoms or a heteroaromatic ring having a nitrogen atom in the figure in the ring.

R ^101a , R ^101b , R ^101c , R ^101d , R ^101e , R ^101f and R ^101g may be the same as or different from each other. Specifically, as an alkyl group, a methyl group, an ethyl group, a propyl group , Isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclopropylmethyl group, 4-methylcyclohexyl Group, cyclohexylmethyl group, norbornyl group, adamantyl group and the like. Examples of the alkenyl group include a vinyl group, an allyl group, a propenyl group, a butenyl group, a hexenyl group, and a cyclohexenyl group. Examples of the oxoalkyl group include 2-oxocyclopentyl group, 2-oxocyclohexyl group, and the like. 2-oxopropyl group, 2-cyclopentyl-2-oxoethyl group, 2-cyclohexyl-2-oxoethyl group, 2- (4 -Methylcyclohexyl) -2-oxoethyl group and the like can be mentioned. Examples of the oxoalkenyl group include 2-oxo-4-cyclohexenyl group and 2-oxo-4-propenyl group. Examples of the aryl group include a phenyl group, a naphthyl group, a p-methoxyphenyl group, an m-methoxyphenyl group, an o-methoxyphenyl group, an ethoxyphenyl group, a p-tert-butoxyphenyl group, and an m-tert-butoxyphenyl group. Alkylphenyl groups such as alkoxyphenyl groups, 2-methylphenyl groups, 3-methylphenyl groups, 4-methylphenyl groups, ethylphenyl groups, 4-tert-butylphenyl groups, 4-butylphenyl groups, dimethylphenyl groups, etc. Alkyl naphthyl groups such as methyl naphthyl group and ethyl naphthyl group, alkoxy naphthyl groups such as methoxy naphthyl group and ethoxy naphthyl group, dialkyl naphthyl groups such as dimethyl naphthyl group and diethyl naphthyl group, dimethoxy naphthyl group and diethoxy naphthyl group Dialkoxynaphthyl group And the like. Examples of the aralkyl group include a benzyl group, a phenylethyl group, and a phenethyl group. As the aryloxoalkyl group, 2-aryl-2-oxoethyl group such as 2-phenyl-2-oxoethyl group, 2- (1-naphthyl) -2-oxoethyl group, 2- (2-naphthyl) -2-oxoethyl group and the like Groups and the like. Non-nucleophilic counter ions of K ⁻ include halide ions such as chloride ion and bromide ion, fluoroalkyl sulfonates such as triflate, 1,1,1-trifluoroethane sulfonate, and nonafluorobutane sulfonate, tosylate, and benzene sulfonate. And aryl sulfonates such as 4-fluorobenzene sulfonate and 1,2,3,4,5-pentafluorobenzene sulfonate, and alkyl sulfonates such as mesylate and butane sulfonate.

The heteroaromatic ring in which R ^101d , R ^101e , R ^101f and R ^101g have a nitrogen atom in the formula is an imidazole derivative (for example, imidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole). Etc.), pyrazole derivatives, furazane derivatives, pyrroline derivatives (eg pyrroline, 2-methyl-1-pyrroline etc.), pyrrolidine derivatives (eg pyrrolidine, N-methylpyrrolidine, pyrrolidinone, N-methylpyrrolidone etc.), imidazoline derivatives, imidazolidine Derivatives, pyridine derivatives (eg pyridine, methylpyridine, ethylpyridine, propylpyridine, butylpyridine, 4- (1-butylpentyl) pyridine, dimethylpyridine, trimethylpyridine, triethylpyridine, phenylpyridine, 3-methyl-2-phenylpyridy 4-tert-butylpyridine, diphenylpyridine, benzylpyridine, methoxypyridine, butoxypyridine, dimethoxypyridine, 1-methyl-2-pyridone, 4-pyrrolidinopyridine, 1-methyl-4-phenylpyridine, 2- (1 -Ethylpropyl) pyridine, aminopyridine, dimethylaminopyridine, etc.), pyridazine derivatives, pyrimidine derivatives, pyrazine derivatives, pyrazoline derivatives, pyrazolidine derivatives, piperidine derivatives, piperazine derivatives, morpholine derivatives, indole derivatives, isoindole derivatives, 1H-indazole derivatives , Indoline derivatives, quinoline derivatives (eg quinoline, 3-quinolinecarbonitrile, etc.), isoquinoline derivatives, cinnoline derivatives, quinazoline derivatives, quinoxaline derivatives, phthalazi Exemplified derivatives, purine derivatives, pteridine derivatives, carbazole derivatives, phenanthridine derivatives, acridine derivatives, phenazine derivatives, 1,10-phenanthroline derivatives, adenine derivatives, adenosine derivatives, guanine derivatives, guanosine derivatives, uracil derivatives, uridine derivatives, etc. Is done.

  (P1a-1) and (P1a-2) have the effects of both a photoacid generator and a thermal acid generator, while (P1a-3) acts as a thermal acid generator.

（式中、Ｒ^102a、Ｒ^102bはそれぞれ炭素数１〜８の直鎖状、分岐状又は環状のアルキル基を示す。Ｒ¹⁰³は炭素数１〜１０の直鎖状、分岐状又は環状のアルキレン基を示す。Ｒ^104a、Ｒ^104bはそれぞれ炭素数３〜７の２−オキソアルキル基を示す。Ｋ^-は非求核性対向イオンを表す。）

(In the formula, R ^102a and R ^102b each represent a linear, branched or cyclic alkyl group having 1 to 8 carbon atoms. R ¹⁰³ is a linear, branched or cyclic alkylene having 1 to 10 carbon atoms. R ^104a and R ^104b each represent a 2-oxoalkyl group having 3 to 7 carbon atoms, and K ⁻ represents a non-nucleophilic counter ion.)

Specific examples of the alkyl group for R ^102a and R ^102b 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 pentyl group, a hexyl group, and a heptyl group. Octyl group, cyclopentyl group, cyclohexyl group, cyclopropylmethyl group, 4-methylcyclohexyl group, cyclohexylmethyl group and the like. As the alkylene group for R ¹⁰³ , methylene group, ethylene group, propylene group, butylene group, pentylene group, hexylene group, heptylene group, octylene group, nonylene group, 1,4-cyclohexylene group, 1,2- Examples include cyclohexylene group, 1,3-cyclopentylene group, 1,4-cyclooctylene group, 1,4-cyclohexanedimethylene group and the like. ^Examples of the 2-oxoalkyl group of R ^104a and R ^104b include a 2-oxopropyl group, a 2-oxocyclopentyl group, a 2-oxocyclohexyl group, and a 2-oxocycloheptyl group. K ^- is the formula (P1a-1), can be exemplified the same ones as described in (P1a-2) and (P1a-3).

（式中、Ｒ¹⁰⁵、Ｒ¹⁰⁶は炭素数１〜１２の直鎖状、分岐状又は環状のアルキル基又はハロゲン化アルキル基、炭素数６〜２０のアリール基又はハロゲン化アリール基、又は炭素数７〜１２のアラルキル基を示す。）

(In the formula, R ¹⁰⁵ and R ¹⁰⁶ are linear, branched or cyclic alkyl groups or halogenated alkyl groups having 1 to 12 carbon atoms, aryl groups or halogenated aryl groups having 6 to 20 carbon atoms, or carbon atoms. 7 to 12 aralkyl groups are shown.)

^Examples of the alkyl group of R ¹⁰⁵ and R ¹⁰⁶ include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, amyl Group, cyclopentyl group, cyclohexyl group, cycloheptyl group, norbornyl group, adamantyl group and the like. Examples of the halogenated alkyl group include a trifluoromethyl group, a 1,1,1-trifluoroethyl group, a 1,1,1-trichloroethyl group, and a nonafluorobutyl group. As the aryl group, an alkoxyphenyl group such as a phenyl group, p-methoxyphenyl group, m-methoxyphenyl group, o-methoxyphenyl group, ethoxyphenyl group, p-tert-butoxyphenyl group, m-tert-butoxyphenyl group, Examples thereof include alkylphenyl groups such as 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, ethylphenyl group, 4-tert-butylphenyl group, 4-butylphenyl group, and dimethylphenyl group. Examples of the halogenated aryl group include a fluorophenyl group, a chlorophenyl group, and 1,2,3,4,5-pentafluorophenyl group. Examples of the aralkyl group include a benzyl group and a phenethyl group.

（式中、Ｒ¹⁰⁷、Ｒ¹⁰⁸、Ｒ¹⁰⁹は炭素数１〜１２の直鎖状、分岐状又は環状のアルキル基又はハロゲン化アルキル基、炭素数６〜２０のアリール基又はハロゲン化アリール基、又は炭素数７〜１２のアラルキル基を示す。Ｒ¹⁰⁸、Ｒ¹⁰⁹は互いに結合して環状構造を形成してもよく、環状構造を形成する場合、Ｒ¹⁰⁸、Ｒ¹⁰⁹はそれぞれ炭素数１〜６の直鎖状又は分岐状のアルキレン基を示す。Ｒ¹⁰⁵は（Ｐ２）式のものと同様である。）

(Wherein R ¹⁰⁷ , R ¹⁰⁸ and R ¹⁰⁹ are each a linear, branched or cyclic alkyl group or halogenated alkyl group having 1 to 12 carbon atoms, an aryl group or halogenated aryl group having 6 to 20 carbon atoms, Or an aralkyl group having 7 to 12 carbon atoms, R ¹⁰⁸ and R ¹⁰⁹ may be bonded to each other to form a cyclic structure, and in the case of forming a cyclic structure, R ¹⁰⁸ and R ¹⁰⁹ each have 1 to 6 carbon atoms. And R ¹⁰⁵ is the same as in the formula (P2).

Examples of the alkyl group, halogenated alkyl group, aryl group, halogenated aryl group, and aralkyl group of R ¹⁰⁷ , R ¹⁰⁸ , and R ¹⁰⁹ include the same groups as those described for R ¹⁰⁵ and R ¹⁰⁶ . ^Examples of the alkylene group for R ¹⁰⁸ and R ¹⁰⁹ include a methylene group, an ethylene group, a propylene group, a butylene group, and a hexylene group.

（式中、Ｒ^101a、Ｒ^101bは前記と同様である。）

(In the formula, R ^101a and R ^101b are the same as described above.)

（式中、Ｒ¹¹⁰は炭素数６〜１０のアリーレン基、炭素数１〜６のアルキレン基又は炭素数２〜６のアルケニレン基を示し、これらの基の水素原子の一部又は全部は更に炭素数１〜４の直鎖状又は分岐状のアルキル基又はアルコキシ基、ニトロ基、アセチル基、又はフェニル基で置換されていてもよい。Ｒ¹¹¹は炭素数１〜８の直鎖状、分岐状又は置換のアルキル基、アルケニル基又はアルコキシアルキル基、フェニル基、又はナフチル基を示し、これらの基の水素原子の一部又は全部は更に炭素数１〜４のアルキル基又はアルコキシ基；炭素数１〜４のアルキル基、アルコキシ基、ニトロ基又はアセチル基で置換されていてもよいフェニル基；炭素数３〜５のヘテロ芳香族基；又は塩素原子、フッ素原子で置換されていてもよい。）

(In the formula, R ¹¹⁰ represents an arylene group having 6 to 10 carbon atoms, an alkylene group having 1 to 6 carbon atoms, or an alkenylene group having 2 to 6 carbon atoms, and some or all of the hydrogen atoms of these groups are further carbon atoms. It may be substituted with a linear or branched alkyl group or alkoxy group having 1 to 4 carbon atoms, a nitro group, an acetyl group, or a phenyl group, and R ¹¹¹ is a linear or branched chain having 1 to 8 carbon atoms. Or a substituted alkyl group, an alkenyl group or an alkoxyalkyl group, a phenyl group, or a naphthyl group, and part or all of the hydrogen atoms of these groups are further an alkyl group or alkoxy group having 1 to 4 carbon atoms; A phenyl group which may be substituted with an alkyl group of 4 to 4, an alkoxy group, a nitro group or an acetyl group; a heteroaromatic group having 3 to 5 carbon atoms; or a phenyl group which may be substituted with a chlorine atom or a fluorine atom.

Here, as the arylene group of R ¹¹⁰ , 1,2-phenylene group, 1,8-naphthylene group, etc., and as the alkylene group, methylene group, ethylene group, trimethylene group, tetramethylene group, phenylethylene group, norbornane Examples of the alkenylene group such as -2,3-diyl group include 1,2-vinylene group, 1-phenyl-1,2-vinylene group, 5-norbornene-2,3-diyl group and the like. The alkyl group for R ¹¹¹ is the same as R ^{101a to} R ^101c, and the alkenyl group is a vinyl group, 1-propenyl group, allyl group, 1-butenyl group, 3-butenyl group, isoprenyl group, 1- Pentenyl group, 3-pentenyl group, 4-pentenyl group, dimethylallyl group, 1-hexenyl group, 3-hexenyl group, 5-hexenyl group, 1-heptenyl group, 3-heptenyl group, 6-heptenyl group, 7-octenyl Groups such as alkoxyalkyl groups include methoxymethyl, ethoxymethyl, propoxymethyl, butoxymethyl, pentyloxymethyl, hexyloxymethyl, heptyloxymethyl, methoxyethyl, ethoxyethyl, Propoxyethyl, butoxyethyl, pentyloxyethyl, hexyloxyethyl, methoxypro Group, ethoxypropyl group, propoxypropyl group, butoxy propyl group, methoxybutyl group, ethoxybutyl group, propoxybutyl group, a methoxy pentyl group, an ethoxy pentyl group, a methoxy hexyl group, a methoxy heptyl group.

  In addition, examples of the optionally substituted alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group. As the alkoxy group of ˜4, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, a tert-butoxy group and the like are an alkyl group having 1 to 4 carbon atoms, an alkoxy group, and a nitro group. As the phenyl group which may be substituted with an acetyl group, a phenyl group, a tolyl group, a p-tert-butoxyphenyl group, a p-acetylphenyl group, a p-nitrophenyl group, etc. are heterocycles having 3 to 5 carbon atoms. Examples of the aromatic group include a pyridyl group and a furyl group.

  Specific examples of the acid generator include onium salts such as tetramethylammonium trifluoromethanesulfonate, tetramethylammonium nonafluorobutanesulfonate, triethylammonium nonafluorobutanesulfonate, pyridinium nonafluorobutanesulfonate, camphorsulfone. Triethylammonium acid, pyridinium camphorsulfonate, tetra-n-butylammonium nonafluorobutanesulfonate, tetraphenylammonium nonafluorobutanesulfonate, tetramethylammonium p-toluenesulfonate, diphenyliodonium trifluoromethanesulfonate, trifluoromethanesulfonic acid ( p-tert-butoxyphenyl) phenyliodonium, p-toluenesulfonic acid diphenyliodo , P-toluenesulfonic acid (p-tert-butoxyphenyl) phenyliodonium, trifluoromethanesulfonic acid triphenylsulfonium, trifluoromethanesulfonic acid (p-tert-butoxyphenyl) diphenylsulfonium, trifluoromethanesulfonic acid bis (p-tert -Butoxyphenyl) phenylsulfonium, trifluoromethanesulfonic acid tris (p-tert-butoxyphenyl) sulfonium, p-toluenesulfonic acid triphenylsulfonium, p-toluenesulfonic acid (p-tert-butoxyphenyl) diphenylsulfonium, p-toluene Bis (p-tert-butoxyphenyl) sulfonic acid phenylsulfonium, Tris (p-tert-butoxyphenyl) p-toluenesulfonic acid Sulfonium, triphenylsulfonium nonafluorobutanesulfonate, triphenylsulfonium butanesulfonate, trimethylsulfonium trifluoromethanesulfonate, trimethylsulfonium p-toluenesulfonate, cyclohexylmethyl (2-oxocyclohexyl) sulfonium trifluoromethanesulfonate, p-toluene Cyclohexylmethyl (2-oxocyclohexyl) sulfonium sulfonate, dimethylphenylsulfonium trifluoromethanesulfonate, dimethylphenylsulfonium p-toluenesulfonate, dicyclohexylphenylsulfonium trifluoromethanesulfonate, dicyclohexylphenylsulfonium p-toluenesulfonate, trifluoromethanesulfonic acid Trinaphthylsulfoni , Trifluoromethanesulfonic acid (2-norbornyl) methyl (2-oxocyclohexyl) sulfonium, ethylenebis [methyl (2-oxocyclopentyl) sulfonium trifluoromethanesulfonate], 1,2'-naphthylcarbonylmethyltetrahydrothiophenium trif Examples include onium salts such as a rate.

  Diazomethane derivatives include bis (benzenesulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, bis (xylenesulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (cyclopentylsulfonyl) diazomethane, bis (n-butylsulfonyl) diazomethane Bis (isobutylsulfonyl) diazomethane, bis (sec-butylsulfonyl) diazomethane, bis (n-propylsulfonyl) diazomethane, bis (isopropylsulfonyl) diazomethane, bis (tert-butylsulfonyl) diazomethane, bis (n-amylsulfonyl) diazomethane Bis (isoamylsulfonyl) diazomethane, bis (sec-amylsulfonyl) diazomethane, bis (tert-amylsulfur) Nyl) diazomethane, 1-cyclohexylsulfonyl-1- (tert-butylsulfonyl) diazomethane, 1-cyclohexylsulfonyl-1- (tert-amylsulfonyl) diazomethane, 1-tert-amylsulfonyl-1- (tert-butylsulfonyl) diazomethane And the like.

  Examples of glyoxime derivatives include bis-O- (p-toluenesulfonyl) -α-dimethylglyoxime, bis-O- (p-toluenesulfonyl) -α-diphenylglyoxime, bis-O- (p-toluenesulfonyl)- α-dicyclohexylglyoxime, bis-O- (p-toluenesulfonyl) -2,3-pentanedione glyoxime, bis-O- (p-toluenesulfonyl) -2-methyl-3,4-pentanedione glyoxime, Bis-O- (n-butanesulfonyl) -α-dimethylglyoxime, bis-O- (n-butanesulfonyl) -α-diphenylglyoxime, bis-O- (n-butanesulfonyl) -α-dicyclohexylglyoxime Bis-O- (n-butanesulfonyl) -2,3-pentanedione glyoxime, bis-O- ( -Butanesulfonyl) -2-methyl-3,4-pentanedione glyoxime, bis-O- (methanesulfonyl) -α-dimethylglyoxime, bis-O- (trifluoromethanesulfonyl) -α-dimethylglyoxime, bis -O- (1,1,1-trifluoroethanesulfonyl) -α-dimethylglyoxime, bis-O- (tert-butanesulfonyl) -α-dimethylglyoxime, bis-O- (perfluorooctanesulfonyl)- α-dimethylglyoxime, bis-O- (cyclohexanesulfonyl) -α-dimethylglyoxime, bis-O- (benzenesulfonyl) -α-dimethylglyoxime, bis-O- (p-fluorobenzenesulfonyl) -α- Dimethylglyoxime, bis-O- (p-tert-butylbenzenesulfonyl) α- dimethylglyoxime, bis -O- (xylene sulfonyl)-.alpha.-dimethylglyoxime, and bis -O- (camphorsulfonyl)-.alpha.-glyoxime derivatives such as dimethylglyoxime.

  Examples of bissulfone derivatives include bisnaphthylsulfonylmethane, bistrifluoromethylsulfonylmethane, bismethylsulfonylmethane, bisethylsulfonylmethane, bispropylsulfonylmethane, bisisopropylsulfonylmethane, bis-p-toluenesulfonylmethane, and bisbenzenesulfonylmethane. Bissulfone derivatives can be mentioned.

Examples of β-ketosulfone derivatives include β-ketosulfone derivatives such as 2-cyclohexylcarbonyl-2- (p-toluenesulfonyl) propane and 2-isopropylcarbonyl-2- (p-toluenesulfonyl) propane.
Examples of the disulfone derivative include disulfone derivatives such as diphenyl disulfone derivatives and dicyclohexyl disulfone derivatives.

Examples of the nitrobenzyl sulfonate derivative include nitrobenzyl sulfonate derivatives such as 2,6-dinitrobenzyl p-toluenesulfonate and 2,4-dinitrobenzyl p-toluenesulfonate.
Examples of sulfonic acid ester derivatives include 1,2,3-tris (methanesulfonyloxy) benzene, 1,2,3-tris (trifluoromethanesulfonyloxy) benzene, 1,2,3-tris (p-toluenesulfonyloxy). Mention may be made of sulfonic acid ester derivatives such as benzene.

  Examples of sulfonic acid ester derivatives of N-hydroxyimide compounds include N-hydroxysuccinimide methanesulfonic acid ester, N-hydroxysuccinimide trifluoromethanesulfonic acid ester, N-hydroxysuccinimide ethanesulfonic acid ester, N-hydroxysuccinimide 1-propanesulfonic acid. Ester, N-hydroxysuccinimide 2-propanesulfonic acid ester, N-hydroxysuccinimide 1-pentanesulfonic acid ester, N-hydroxysuccinimide 1-octanesulfonic acid ester, N-hydroxysuccinimide p-toluenesulfonic acid ester, N-hydroxysuccinimide p-methoxybenzenesulfonic acid ester, N-hydroxysuccinimide 2-chloroethanesulfonic acid ester N-hydroxysuccinimide benzenesulfonic acid ester, N-hydroxysuccinimide-2,4,6-trimethylbenzenesulfonic acid ester, N-hydroxysuccinimide 1-naphthalenesulfonic acid ester, N-hydroxysuccinimide 2-naphthalenesulfonic acid ester, N- Hydroxy-2-phenylsuccinimide methanesulfonate, N-hydroxymaleimide methanesulfonate, N-hydroxymaleimide ethanesulfonate, N-hydroxy-2-phenylmaleimide methanesulfonate, N-hydroxyglutarimide methanesulfonate Ester, N-hydroxyglutarimide benzenesulfonic acid ester, N-hydroxyphthalimide methanesulfonic acid ester, N-hydro Siphthalimidobenzenesulfonic acid ester, N-hydroxyphthalimide trifluoromethanesulfonic acid ester, N-hydroxyphthalimide p-toluenesulfonic acid ester, N-hydroxynaphthalimide methanesulfonic acid ester, N-hydroxynaphthalimide benzenesulfonic acid ester, N- Hydroxy-5-norbornene-2,3-dicarboximide methanesulfonate, N-hydroxy-5-norbornene-2,3-dicarboximide trifluoromethanesulfonate, N-hydroxy-5-norbornene-2,3 -Sulphonic acid ester derivatives of N-hydroxyimide compounds such as dicarboximide p-toluenesulfonic acid ester.

In particular, triphenylsulfonium trifluoromethanesulfonate, trifluoromethanesulfonate (p-tert-butoxyphenyl) diphenylsulfonium, tris (p-tert-butoxyphenyl) sulfonium trifluoromethanesulfonate, triphenylsulfonium p-toluenesulfonate, p -Toluenesulfonic acid (p-tert-butoxyphenyl) diphenylsulfonium, p-toluenesulfonic acid tris (p-tert-butoxyphenyl) sulfonium, trifluoromethanesulfonic acid trinaphthylsulfonium, trifluoromethanesulfonic acid cyclohexylmethyl (2-oxocyclohexyl) ) Sulfonium, (2-norbornyl) methyl (2-oxocyclohexyl) sulfonyl trifluoromethanesulfonate , 1,2'-naphthyl carbonyl methyl tetrahydrothiophenium triflate onium salts such as,
Bis (benzenesulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (n-butylsulfonyl) diazomethane, bis (isobutylsulfonyl) diazomethane, bis (sec-butylsulfonyl) diazomethane, bis ( diazomethane derivatives such as n-propylsulfonyl) diazomethane, bis (isopropylsulfonyl) diazomethane, bis (tert-butylsulfonyl) diazomethane,
Glyoxime derivatives such as bis-O- (p-toluenesulfonyl) -α-dimethylglyoxime, bis-O- (n-butanesulfonyl) -α-dimethylglyoxime,
Bissulfone derivatives such as bisnaphthylsulfonylmethane,
N-hydroxysuccinimide methanesulfonic acid ester, N-hydroxysuccinimide trifluoromethanesulfonic acid ester, N-hydroxysuccinimide 1-propanesulfonic acid ester, N-hydroxysuccinimide 2-propanesulfonic acid ester, N-hydroxysuccinimide 1-pentanesulfonic acid A sulfonic acid ester derivative of an N-hydroxyimide compound such as an ester, N-hydroxysuccinimide p-toluenesulfonic acid ester, N-hydroxynaphthalimide methanesulfonic acid ester, or N-hydroxynaphthalimide benzenesulfonic acid ester is preferably used.

  In addition, the said acid generator can be used individually by 1 type or in combination of 2 or more types.

  The addition amount of the acid generator is preferably 0.1 to 50 parts, more preferably 0.5 to 40 parts with respect to 100 parts of the base polymer. If the amount is less than 0.1 part, the amount of acid generated is small and the crosslinking reaction may be insufficient. If the amount exceeds 50 parts, a mixing phenomenon may occur due to the acid moving to the upper resist.

Furthermore, the resist underlayer film material of the present invention can be blended with a basic compound for improving storage stability.
The basic compound serves as a quencher for the acid to prevent the acid generated in a trace amount from the acid generator during storage and the like from causing the crosslinking reaction to proceed.

  Examples of such basic compounds include primary, secondary, and tertiary aliphatic amines, hybrid amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxy group, and sulfonyl groups. A nitrogen-containing compound having a hydroxyl group, a nitrogen-containing compound having a hydroxyl group, a nitrogen-containing compound having a hydroxyphenyl group, an alcoholic nitrogen-containing compound, an amide derivative, an imide derivative, and the like.

  Specifically, primary aliphatic amines include ammonia, methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, pentylamine, tert- Amylamine, cyclopentylamine, hexylamine, cyclohexylamine, heptylamine, octylamine, nonylamine, decylamine, dodecylamine, cetylamine, methylenediamine, ethylenediamine, tetraethylenepentamine, etc. are exemplified as secondary aliphatic amines. Dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, diisobutylamine, di-sec-butylamine, dipentylamine, disi Lopentylamine, dihexylamine, dicyclohexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, didodecylamine, dicetylamine, N, N-dimethylmethylenediamine, N, N-dimethylethylenediamine, N, N-dimethyltetraethylenepenta Examples of tertiary aliphatic amines include trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, triisobutylamine, tri-sec-butylamine, and tripentylamine. , Tricyclopentylamine, trihexylamine, tricyclohexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, tridodecylamine, Examples include cetylamine, N, N, N ′, N′-tetramethylmethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetramethyltetraethylenepentamine and the like. Is done.

  Examples of hybrid amines include dimethylethylamine, methylethylpropylamine, benzylamine, phenethylamine, and benzyldimethylamine.

  Specific examples of aromatic amines and heterocyclic amines include aniline derivatives (eg, aniline, N-methylaniline, N-ethylaniline, N-propylaniline, N, N-dimethylaniline, 2-methylaniline, 3- Methylaniline, 4-methylaniline, ethylaniline, propylaniline, trimethylaniline, 2-nitroaniline, 3-nitroaniline, 4-nitroaniline, 2,4-dinitroaniline, 2,6-dinitroaniline, 3,5- Dinitroaniline, N, N-dimethyltoluidine, etc.), diphenyl (p-tolyl) amine, methyldiphenylamine, triphenylamine, phenylenediamine, naphthylamine, diaminonaphthalene, pyrrole derivatives (eg pyrrole, 2H-pyrrole, 1-methylpyrrole, 2,4-dim Lupyrrole, 2,5-dimethylpyrrole, N-methylpyrrole, etc.), oxazole derivatives (eg oxazole, isoxazole etc.), thiazole derivatives (eg thiazole, isothiazole etc.), imidazole derivatives (eg imidazole, 4-methylimidazole, 4 -Methyl-2-phenylimidazole, etc.), pyrazole derivatives, furazane derivatives, pyrroline derivatives (eg pyrroline, 2-methyl-1-pyrroline etc.), pyrrolidine derivatives (eg pyrrolidine, N-methylpyrrolidine, pyrrolidinone, N-methylpyrrolidone etc.) ), Imidazoline derivatives, imidazolidine derivatives, pyridine derivatives (eg pyridine, methylpyridine, ethylpyridine, propylpyridine, butylpyridine, 4- (1-butylpentyl) pyridine, dimethyl) Lysine, trimethylpyridine, triethylpyridine, phenylpyridine, 3-methyl-2-phenylpyridine, 4-tert-butylpyridine, diphenylpyridine, benzylpyridine, methoxypyridine, butoxypyridine, dimethoxypyridine, 1-methyl-2-pyridone, 4-pyrrolidinopyridine, 1-methyl-4-phenylpyridine, 2- (1-ethylpropyl) pyridine, aminopyridine, dimethylaminopyridine, etc.), pyridazine derivatives, pyrimidine derivatives, pyrazine derivatives, pyrazoline derivatives, pyrazolidine derivatives, piperidine Derivatives, piperazine derivatives, morpholine derivatives, indole derivatives, isoindole derivatives, 1H-indazole derivatives, indoline derivatives, quinoline derivatives (eg quinoline, 3-quinoline carbo Nitriles), isoquinoline derivatives, cinnoline derivatives, quinazoline derivatives, quinoxaline derivatives, phthalazine derivatives, purine derivatives, pteridine derivatives, carbazole derivatives, phenanthridine derivatives, acridine derivatives, phenazine derivatives, 1,10-phenanthroline derivatives, adenine derivatives, adenosine Examples include derivatives, guanine derivatives, guanosine derivatives, uracil derivatives, uridine derivatives and the like.

  Furthermore, examples of the nitrogen-containing compound having a carboxy group include aminobenzoic acid, indolecarboxylic acid, amino acid derivatives (eg, nicotinic acid, alanine, arginine, aspartic acid, glutamic acid, glycine, histidine, isoleucine, glycylleucine, leucine, methionine , Phenylalanine, threonine, lysine, 3-aminopyrazine-2-carboxylic acid, methoxyalanine) and the like, and examples of the nitrogen-containing compound having a sulfonyl group include 3-pyridinesulfonic acid, pyridinium p-toluenesulfonate, and the like. Nitrogen-containing compounds having a hydroxyl group, nitrogen-containing compounds having a hydroxyphenyl group, and alcoholic nitrogen-containing compounds include 2-hydroxypyridine, aminocresol, 2,4-quinolinediol, and 3-indolemethanol. Drate, monoethanolamine, diethanolamine, triethanolamine, N-ethyldiethanolamine, N, N-diethylethanolamine, triisopropanolamine, 2,2'-iminodiethanol, 2-aminoethanol, 3-amino-1-propanol 4-amino-1-butanol, 4- (2-hydroxyethyl) morpholine, 2- (2-hydroxyethyl) pyridine, 1- (2-hydroxyethyl) piperazine, 1- [2- (2-hydroxyethoxy) Ethyl] piperazine, piperidineethanol, 1- (2-hydroxyethyl) pyrrolidine, 1- (2-hydroxyethyl) -2-pyrrolidinone, 3-piperidino-1,2-propanediol, 3-pyrrolidino-1,2-propane Diol, 8-hydroxyuroli , 3-cuincridinol, 3-tropanol, 1-methyl-2-pyrrolidineethanol, 1-aziridineethanol, N- (2-hydroxyethyl) phthalimide, N- (2-hydroxyethyl) isonicotinamide, etc. Illustrated.

Examples of the amide derivatives include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide and the like.
Examples of imide derivatives include phthalimide, succinimide, maleimide and the like.

  The compounding amount of the basic compound is suitably 0.001 to 2 parts, particularly 0.01 to 1 part, based on 100 parts of the total base polymer. If the blending amount is less than 0.001 part, the blending effect is small, and if it exceeds 2 parts, all of the acid generated by heat may be trapped and not crosslinked.

  The organic solvent that can be used in the resist underlayer film material of the present invention is not particularly limited as long as it dissolves the base polymer, acid generator, crosslinking agent, and other additives. Specific examples thereof include ketones such as cyclohexanone and methyl-2-amyl ketone; 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol and the like. Alcohols: ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether; propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, lactic acid Ethyl, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate , Tert-butyl acetate, tert-butyl propionate, propylene glycol monomethyl ether acetate, propylene glycol mono tert-butyl ether acetate and the like, and one or more of these can be used in combination. It is not limited. Among these organic solvents, diethylene glycol dimethyl ether, 1-ethoxy-2-propanol, ethyl lactate, propylene glycol monomethyl ether acetate and mixed solvents thereof are preferably used in the resist underlayer film material of the present invention.

  The blending amount of the organic solvent is preferably 200 to 10,000 parts, particularly preferably 300 to 5,000 parts with respect to 100 parts of the total base polymer.

  Furthermore, the present invention is a method of forming a pattern on a substrate by lithography, wherein at least a resist underlayer film is formed on the substrate using the resist underlayer film material of the present invention, and a photoresist is formed on the underlayer film. The resist upper layer film of the composition is formed to form a multilayer resist film, the pattern circuit region of the multilayer resist film is exposed, and then developed with a developing solution to form a resist pattern on the resist upper layer film. A pattern forming method is provided in which a resist underlayer film is etched using a resist upper layer film as a mask, and a substrate is etched using a multilayer resist film having a pattern formed as a mask to form a pattern on the substrate. .

Hereinafter, the pattern forming method of the present invention will be described with reference to FIG.
First, the resist underlayer film 12 can be formed on the substrate 11 by a spin coat method or the like in the same manner as a normal photoresist film formation method. After the resist underlayer film 12 is formed by a spin coating method or the like, it is desirable to evaporate the organic solvent and perform baking to promote the crosslinking reaction in order to prevent mixing with the resist upper layer film 13. The baking temperature is preferably in the range of 80 to 300 ° C. and in the range of 10 to 300 seconds. Although the thickness of the resist underlayer film 12 is appropriately selected, it is preferably 100 to 20,000 nm, particularly 150 to 15,000 nm. After the resist lower layer film 12 is formed, a resist upper layer film 13 is formed thereon (see FIG. 4A).

  In this case, a known composition can be used as the photoresist composition for forming the resist upper layer film 13. From the point of oxygen gas etching resistance, etc., using a silicon atom-containing polymer such as a polysilsesquioxane derivative or vinylsilane derivative as a base polymer, and a positive type containing an organic solvent, an acid generator, and a basic compound if necessary The photoresist composition is used. In addition, as a silicon atom containing polymer, the well-known polymer used for this kind of resist composition can be used.

When forming the resist upper layer film 13 with the said photoresist composition, a spin coat method etc. are used preferably similarly to the case where the said resist lower layer film is formed. Pre-baking is performed after the resist upper layer film 13 is formed by spin coating or the like, but it is preferably performed at 80 to 180 ° C. for 10 to 300 seconds.
Thereafter, according to a conventional method, the pattern circuit region of the multilayer resist film is exposed, post-exposure bake (PEB), and developed to obtain a resist pattern (see FIG. 4B).
The thickness of the resist upper layer film 13 is not particularly limited, but is preferably 30 to 500 nm, particularly 50 to 400 nm.
For the development, a paddle method using an alkaline aqueous solution, a dip method, or the like is used, and in particular, a paddle method using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide is preferably used. Then, the substrate is rinsed with pure water and dried by spin drying or nitrogen blowing.

Next, the resist lower layer film 12 is etched by dry etching mainly using oxygen gas using the resist upper layer film 13 on which the resist pattern is formed as a mask (see FIG. 4C). This etching can be performed by a conventional method. In the case of dry etching mainly using oxygen gas, in addition to oxygen gas, it is also possible to add inert gas such as He and Ar, and CO, CO ₂ , NH ₃ , SO ₂ , N ₂ and NO ₂ gas. is there. In particular, the latter gas is used for side wall protection for preventing undercut of the pattern side wall.

Etching of the next substrate 11 can also be performed by a conventional method. For example, if the substrate is SiO ₂ or SiN, etching mainly using a chlorofluorocarbon gas, polysilicon (p-Si), Al, or W is chlorine, Etching mainly using a bromine-based gas is performed (see FIG. 4D). The resist underlayer film of the present invention is characterized by excellent etching resistance when etching these substrates. At this time, if necessary, the resist upper layer film may be removed and then the substrate may be etched, or the substrate may be etched while leaving the resist upper layer film as it is.

As shown in FIG. 4, the substrate 11 may be composed of a layer to be processed 11a and a base layer 11b. The base layer 11b of the substrate 11 is not particularly limited, and Si, amorphous silicon (α-Si), p-Si, SiO ₂ , SiN, SiON, W, TiN, Al, etc. Different materials may be used. The layer to be processed _{11a, Si, SiO 2, SiON} , SiN, p-Si, α-Si, W, W-Si, Al, Cu, Al-Si , etc. and various low dielectric films and etching stopper film It is usually used and can be formed to a thickness of 50 to 10,000 nm, particularly 100 to 5,000 nm.

EXAMPLES Hereinafter, although a synthesis example, a comparative synthesis example, an Example, and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited by these description.
(Synthesis Example 1)
To a 200 mL flask, 15.2 g of acenaphthylene, 14.1 g of N-hydroxyethylmaleimide and 15 g of tetrahydrofuran as a solvent were added. The reaction vessel was cooled to −70 ° C. in a nitrogen atmosphere, and vacuum degassing and nitrogen flow were repeated three times. After raising the temperature to room temperature, 2.5 g of 2,2′-azobis (2,4-dimethylvaleronitrile) was added as a polymerization initiator, and the temperature was raised to 55 ° C., followed by reaction for 25 hours. The reaction solution was diluted by adding 5 mL of acetone and then precipitated in 2 L of isopropyl alcohol, and the resulting white solid was filtered and dried under reduced pressure at 40 ° C. to obtain 21 g of a white polymer.

When the obtained polymer was measured by ¹³ C, ¹ H-NMR and GPC, the following analysis results were obtained.
Copolymerization composition ratio Acenaphthylene: N-hydroxyethylmaleimide = 50: 50
Mass average molecular weight (Mw) = 9800
Molecular weight distribution (Mw / Mn) = 1.79
This polymer is referred to as polymer 1.

(Synthesis Example 2)
To a 200 mL flask, 15.2 g of acenaphthylene, 4.5 g of allyl acetate, and 15 g of tetrahydrofuran as a solvent were added. 1 g of concentrated sulfuric acid was added as a polymerization initiator, and the temperature was raised to 60 ° C., followed by reaction for 25 hours. To this reaction solution, 30 g of triethylamine and 10 g of water were added, a deprotection reaction was performed at 60 ° C. for 2 hours, and neutralized with acetic acid. The reaction solution was concentrated and then dissolved in 0.5 L of acetone, and precipitation, filtration and drying were performed in the same manner as above to obtain 14 g of a white polymer.

When the obtained polymer was measured by ¹³ C, ¹ H-NMR and GPC, the following analysis results were obtained.
Copolymerization composition ratio Acenaphthylene: Allyl alcohol = 66: 34
Mass average molecular weight (Mw) = 8500
Molecular weight distribution (Mw / Mn) = 1.98
This polymer is designated as Polymer 2.

(Synthesis Example 3)
To a 200 mL flask, 15.2 g of acenaphthylene, 11.5 g of 3,4-dihydro-2-acetoxyethyl-2H-pyran, and 15 g of tetrahydrofuran as a solvent were added. 1 g of concentrated sulfuric acid was added as a polymerization initiator, and the temperature was raised to 60 ° C., followed by reaction for 25 hours. To this reaction solution, 30 g of triethylamine and 10 g of water were added for deprotection reaction, and neutralized with acetic acid. The reaction solution was concentrated and then dissolved in 0.5 L of acetone, and precipitation, filtration and drying were performed in the same manner as above to obtain 16 g of a white polymer.

When the obtained polymer was measured by ¹³ C, ¹ H-NMR and GPC, the following analysis results were obtained.
Copolymerization composition ratio Acenaphthylene: 3,4-dihydro-2-hydroxyethyl-2H-pyran = 62: 38
Mass average molecular weight (Mw) = 6700
Molecular weight distribution (Mw / Mn) = 1.58
This polymer is designated as Polymer 3.

(Synthesis Example 4)
To a 200 mL flask, 15.2 g of acenaphthylene, 3.3 g of 4-hydroxystyrene, and 60 g of 1,2-dichloroethane as a solvent were added. 1 g of trifluoroboron was added as a polymerization initiator, and the temperature was raised to 60 ° C., followed by reaction for 25 hours. 1 L of methanol and 500 g of water were added to this reaction solution to precipitate a polymer, and the resulting white solid was filtered and dried to obtain 12 g of a white polymer.

When the obtained polymer was measured by ¹³ C, ¹ H-NMR and GPC, the following analysis results were obtained.
Copolymerization composition ratio Acenaphthylene: 4-hydroxystyrene = 75:25
Mass average molecular weight (Mw) = 8800
Molecular weight distribution (Mw / Mn) = 1.82
This polymer is designated as polymer 4.

(Comparative Synthesis Example 1)
To a 500 mL flask, 40 g of 4-hydroxystyrene, 160 g of 2-methacrylic acid-1-adamantane, and 40 g of toluene as a solvent were added. The reaction vessel was cooled to −70 ° C. in a nitrogen atmosphere, and vacuum degassing and nitrogen flow were repeated three times. After raising the temperature to room temperature, 4.1 g of AIBN was added as a polymerization initiator, and the temperature was raised to 80 ° C. and reacted for 24 hours. This reaction solution was concentrated to 1/2, precipitated in a mixed solution of 300 mL of methanol and 50 mL of water, and the obtained white solid was filtered and dried under reduced pressure at 60 ° C. to obtain 188 g of a white polymer.

When the obtained polymer was measured by ¹ H-NMR and GPC, the following analysis results were obtained.
Copolymerization composition ratio 4-hydroxystyrene: 2-methacrylic acid-1-adamantane = 0.32: 0.68
Mass average molecular weight (Mw) = 10900
Molecular weight distribution (Mw / Mn) = 1.77
This polymer is referred to as comparative polymer 1.

(Examples and comparative examples)
[Preparation of resist underlayer film material]
FC-430 (manufactured by Sumitomo 3M) 0.1 resin represented by the above polymers 1 to 4, resin represented by comparative polymer 1, acid generator represented by AG1 and AG2, and crosslinking agent represented by CR1 Resist underlayer film materials (Examples 1 to 5 and Comparative Example 1) were respectively prepared by dissolving them in an organic solvent containing mass% at a ratio shown in Table 1 and filtering with a filter made of 0.1 μm fluororesin. .

架橋剤： ＣＲ１

有機溶剤：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）、
ＰＧＭＥ（プロピレングリコールモノメチルエーテル） Polymers 1-4: From Synthesis Examples 1-4 Comparative polymer 1: From Comparative Synthesis Example 1 Acid generators: AG1, AG2 (see the following structural formula)

Cross-linking agent: CR1

Organic solvent: PGMEA (propylene glycol monomethyl ether acetate),
PGME (propylene glycol monomethyl ether)

A solution of the resist underlayer film material (Examples 1 to 5 and Comparative Example 1) thus prepared is applied on a silicon substrate and baked at 200 ° C. for 60 seconds to form a resist underlayer film having a thickness of 500 nm. did.
After formation of the resist underlayer film, J.P. A. The refractive index (n, k) at a wavelength of 193 nm was determined using a spectroscopic ellipsometer (VASE) with variable incident angle from Woollam, and the results are shown in Table 1.

  As shown in Table 1, in Examples 1 to 5, the n value of the refractive index of the resist underlayer film is in the range of 1.5 to 1.9, and the k value is in the range of 0.13 to 0.4, particularly 200 nm. It can be seen that the film has the optimum refractive index (n) and extinction coefficient (k) that can exhibit a sufficient antireflection effect with the above film thickness.

[Preparation of resist upper layer film material]
The following polymers (ArF silicon-containing polymers 1 and 2) were prepared as the base resin for the resist upper layer film.

ArF silicon-containing polymer 1 is a polymer composed of the repeating units d, e, and f shown above. The copolymer composition ratio and mass average molecular weight (Mw) of this polymer are shown below.
Copolymerization composition ratio d: e: f = 0.4: 0.5: 0.1
Mass average molecular weight (Mw) = 8,800

The ArF silicon-containing polymer 2 is a polymer composed of the repeating units g, h, i shown above. The copolymer composition ratio and mass average molecular weight (Mw) of this polymer are shown below.
Copolymer composition ratio g: h: i = 0.3: 0.5: 0.2
Mass average molecular weight (Mw) = 3,500

  Solutions of resist upper layer film materials 1 and 2 comprising the prepared polymers (ArF silicon-containing polymers 1 and 2), acid generators PAG1 and 2, base additive AACN, and an organic solvent were prepared.

塩基添加剤： ＡＡＣＮ（下記構造式参照）

有機溶剤： 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） Each composition in Table 2 is as follows.
Acid generator: PAG1, PAG2 (see structural formula below)

Base additive: AACN (see structural formula below)

Organic solvent: PGMEA (propylene glycol monomethyl ether acetate)

[Observation of pattern shape, etching resistance test]
(1) Observation of pattern shape 1) Observation of resist pattern shape A solution of the resist underlayer film material (Examples 1 to 5 and Comparative Example 1) prepared above was applied on a substrate having a SiO ₂ film thickness of 300 nm. The resist underlayer film having a thickness of 500 nm was formed by baking at 200 ° C. for 60 seconds.

  Next, the above-prepared solutions of resist upper layer film materials 1 and 2 are applied on the resist lower layer film in the combinations shown in Table 3, and baked at 110 ° C. for 60 seconds to form a silicon-containing resist upper layer having a thickness of 200 nm. A film was formed.

  Next, the film was exposed with an ArF exposure apparatus (Nikon Corp .; S305B, NA 0.68, σ 0.85, 2/3 ring illumination, Cr mask), baked at 110 ° C. for 90 seconds (PEB), and 2.38% by mass. Development was carried out with an aqueous solution of tetramethylammonium hydroxide (TMAH) for 60 seconds to obtain a positive pattern of 0.12 μmL / S (line and space). Table 3 shows the results obtained by observing the obtained resist pattern shape (cross-sectional shape of the silicon-containing resist upper layer film) with an electron microscope (S-4700) manufactured by Hitachi, Ltd.

  As a result, when the resist underlayer film materials of Examples 1 to 5 were used, it was confirmed that no bottoming, undercut, or intermixing phenomenon occurred in the vicinity of the resist underlayer film, and a rectangular pattern was obtained. did.

2) Observation of the cross-sectional shape of the resist underlayer film after dry etching mainly containing oxygen gas Next, the silicon-containing resist upper layer film formed with the resist pattern of 0.12 μmL / S obtained after the ArF exposure and development is masked Then, dry etching mainly using oxygen gas was performed to transfer the pattern to the resist underlayer film.

Etching conditions are as shown below.
Chamber pressure 450 mTorr (60.0 Pa)
RF power 600W
Ar gas flow rate 40sccm
O ₂ gas flow rate 60sccm
Gap 9mm
Time 20sec

  Table 3 shows the results of observation of the pattern shape (cross-sectional shape of the resist underlayer film) after dry etching mainly containing the oxygen gas with an electron microscope (S-4700) manufactured by Hitachi, Ltd. As a result, when the resist underlayer film materials of Examples 1 to 5 were used, it was confirmed that the cross-sectional shape of the resist underlayer film was a vertical shape.

3) Observation of cross-sectional shape of resist underlayer film after etching with CHF ₃ / CF ₄ gas Next, after dry etching mainly using the oxygen gas, the resist underlayer film having a pattern is used as a mask to form CHF ₃ Etching with / CF ₄ gas was performed to process the SiO ₂ substrate.

Etching conditions are as shown below.
Chamber pressure 40.0Pa
RF power 1,300W
Gap 9mm
CHF ₃ gas flow rate 30ml / min
CF ₄ gas flow rate 30ml / min
Ar gas flow rate 100ml / min
60 sec

The cross-sectional shape of the pattern after etching with CHF ₃ / CF ₄ gas for substrate processing (cross-sectional shape of the resist underlayer film) was observed with an electron microscope (S-4700) manufactured by Hitachi, Ltd., and the results are shown in Table 3. Summarized. As a result, in the case where the resist underlayer film materials of Examples 1 to 5 were used, it was confirmed that the cross-sectional shape of the resist underlayer film after the substrate processing etching was also vertical and good.

(2) Dry etching resistance test In the dry etching resistance test, the solution of the resist underlayer film material (Examples 1 to 5 and Comparative Example 1) prepared above was applied on a silicon substrate and baked at 200 ° C for 60 seconds. A resist underlayer film having a thickness of 500 nm was formed. This was evaluated under the following two conditions.

1) Etch resistance test with CHF ₃ / CF ₄ gas The difference in film thickness of the resist underlayer film before and after etching was measured using a dry etching apparatus TE-8500P manufactured by Tokyo Electron Limited.
Etching conditions are the same as above.
The results are shown in Table 4.

₂₎ Cl 2 / BCl ₃ system using an etching test Nichiden Anelva Co., Ltd. dry etching apparatus L-507D-L Gas was determined film thickness difference of the resist underlayer film before and after the etching.

Etching conditions are as shown below.
Chamber pressure 40.0Pa
RF power 300W
Gap 9mm
Cl ₂ gas flow rate 30ml / min
BCl ₃ gas flow rate 30ml / min
CHF ₃ gas flow rate 100ml / min
O ₂ gas flow rate 2ml / min
60 sec
The results are shown in Table 5.

As shown in Tables 4 and 5, the rate of CHF ₃ / CF ₄ gas and Cl ₂ / BCl ₃ gas etching is also comparable to that of the novolak resin, and compared with the polyhydroxystyrene adamantane acrylate copolymer of Comparative Example 1. It can be seen that the speed is low and the etching resistance is high.

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

It is a graph which shows the relationship between the film thickness of an antireflection film, and a reflectance. A graph showing the relationship between the thickness of the resist underlayer film and the reflectance when the extinction coefficient k of the resist underlayer film is fixed at 0.3 and the refractive index n is changed in the range of 1.0 to 2.0. (The exposure wavelength is 193 nm, the n value of the resist upper layer film is 1.74, and the k value is 0.02.) A graph showing the relationship between the thickness of the resist underlayer film and the reflectance when the refractive index n of the resist underlayer film is fixed at 1.5 and the extinction coefficient k is changed in the range of 0.1 to 0.8. (The exposure wavelength is 193 nm, the n value of the resist upper layer film is 1.74, and the k value is 0.02.) It is explanatory drawing which shows an example of the pattern formation method of this invention.

Explanation of symbols

11 ... Substrate, 11a ... Layer to be processed, 11b ... Base layer,
12: resist underlayer film, 13 ... resist upper layer film.

Claims (5)

A resist underlayer film material for a multilayer resist film used in lithography, comprising at least a polymer obtained by copolymerizing a repeating unit of acenaphthylenes and a repeating unit having a substituted or unsubstituted hydroxy group A resist underlayer film material, wherein the polymer has a repeating unit represented by the following general formula (1).

(In the general formula (1), the repeating unit represented by a is

One of them . R ⁴ is a hydrogen atom or a glycidyl group. X represents a polymer of any one of a hydrocarbon containing an indene skeleton, a cycloolefin having 3 to 10 carbon atoms, and a maleimide, and may have any of ether, ester, lactone, and carboxylic anhydride. R ⁵ and R ⁶ are each a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R ⁷ is any one of a hydrogen atom, a linear, branched, and cyclic alkyl group having 1 to 6 carbon atoms, a hydroxy group, and an alkoxycarbonyl group. p and q are integers of 1 to 4, respectively. r is an integer of 0-4. a, b, c are 0.5 ≦ a + b + c ≦ 1, 0 ≦ a ≦ 0.8, 0 ≦ b ≦ 0.8, 0.1 ≦ a + b ≦ 0.8, 0.1 ≦ c ≦ 0, respectively. The range is 8. )   The resist underlayer film material according to claim 1, wherein the resist underlayer film material further contains one or more of an organic solvent, an acid generator, and a crosslinking agent.   A method of forming a pattern on a substrate by lithography, wherein a resist underlayer film is formed on the substrate using at least the resist underlayer film material according to claim 1, and a photoresist is formed on the underlayer film. The resist upper layer film of the composition is formed to form a multilayer resist film, the pattern circuit region of the multilayer resist film is exposed, and then developed with a developing solution to form a resist pattern on the resist upper layer film. A pattern forming method comprising: etching a resist lower layer film using a resist upper layer film as a mask; and etching the substrate using a multilayer resist film having a pattern formed as a mask to form a pattern on the substrate.   4. The resist upper layer film containing silicon atoms is used, and etching of the resist lower layer film using the resist upper layer film as a mask is performed by dry etching mainly using oxygen gas. Pattern formation method.   4. The etching of a substrate using the multilayer resist film on which the pattern is formed as a mask is performed by dry etching mainly using any one of a chlorofluorocarbon gas, a chlorinated gas, and a brominated gas. Item 5. The pattern forming method according to Item 4.

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