JP4662052B2 - Photoresist underlayer film forming material and pattern forming method - Google Patents

Description

The present invention relates to an underlayer film forming material effective in a multilayer resist process used for microfabrication in a manufacturing process of a semiconductor element and the like, and far ultraviolet rays, KrF excimer laser light (248 nm), ArF excimer laser light (193 nm) using the same, The present invention relates to a resist pattern forming method suitable for F ₂ laser light (157 nm), Kr ₂ laser light (146 nm), Ar ₂ laser light (126 nm), soft X-ray, electron beam, ion beam, and X-ray exposure.

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

  On the other hand, conventionally, it is known that a two-layer resist method is excellent for forming a pattern with a high aspect ratio on a stepped substrate, and further, a two-layer resist film is developed with a general alkaline developer. Requires a high molecular silicone compound having a hydrophilic group such as a hydroxy group or a carboxyl group.

As the silicone-based chemically amplified positive resist material, 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. And a silicon-based chemically amplified positive resist material for KrF excimer lasers in which an acid generator is combined (Patent Document 1: JP-A-6-118651, Non-Patent Document 1: SPIE vol. 1925 (1993) p377 Etc.). For ArF excimer lasers, a positive resist based on silsesquioxane in which cyclohexyl carboxylic acid is substituted with an acid labile group has been proposed (Patent Documents 2 and 3: JP-A-10-324748). No. 1, JP-A-11-302382, Non-Patent Document 2: SPIE vol. 3333 (1998) p62). Furthermore, for F ₂ lasers, a positive resist based on silsesquioxane having hexafluoroisopropanol as a soluble group has been proposed (Patent Document 4: Japanese Patent Application Laid-Open No. 2002-55456). The polymer contains a polysilsesquioxane having a ladder skeleton formed by condensation polymerization of trialkoxysilane or trihalogenated silane in the main chain.

  Silicon-containing (meth) acrylic ester-based polymers have been proposed as resist base polymers in which silicon is pendant to the side chain (Patent Document 5: Japanese Patent Laid-Open No. 9-110938, Non-Patent Document 3: J. Photopolymer). Sci. And Technol., Vol. 9 No. 3 (1996) p435-446 etc.).

  The lower layer film of the two-layer resist method is a hydrocarbon compound that can be etched with oxygen gas, and further serves as a mask when etching the underlying substrate, and therefore needs to have high etching resistance. In oxygen gas etching, it is necessary to be composed only of hydrocarbons that do not contain silicon atoms. In addition, in order to improve the line width controllability of the upper-layer silicon-containing resist and reduce pattern sidewall irregularities and pattern collapse due to standing waves, it also has a function as an antireflection film, specifically the lower layer It is necessary to suppress the reflectance from the film into the resist film to 1% or less.

  Here, the results of calculating the reflectance up to a maximum film thickness of 500 nm are shown in FIGS. Assuming that the exposure wavelength is 193 nm, the n value of the upper layer resist is 1.74, and the k value is 0.02, the k value of the lower layer film is fixed at 0.3 in FIG. -2.0, the horizontal axis represents the substrate reflectance when the film thickness is varied in the range of 0 to 500 nm. Assuming a lower layer film for a two-layer resist having a film thickness of 300 nm or more, the reflectance can be reduced to 1% or less in the range of 1.6 to 1.9, which is the same as or slightly higher than the upper layer resist. An optimal value exists.

  FIG. 2 shows the reflectance when the n value of the lower layer film is fixed to 1.5 and the k value is varied in the range of 0 to 1.0. The reflectance can be reduced to 1% or less when the k value is in the range of 0.24 to 0.15. On the other hand, the optimum k value of the antireflection film for a single layer resist used in a thin film of about 40 nm is 0.4 to 0.5, which is different from the optimum k value of the lower layer for a two layer resist used at 300 nm or more. It has been shown that a lower layer for a two-layer resist requires a lower k value, that is, a more transparent lower layer film.

  Here, as a lower layer film forming material for 193 nm, SPIE vol. 4345 (2001) p50 (non-patent document 4), a copolymer of polyhydroxystyrene and an acrylic compound has been studied. Polyhydroxystyrene has a very strong absorption at 193 nm, and the k value alone is a high value of around 0.6. Therefore, the k value is adjusted to around 0.25 by copolymerizing with an acrylic compound having a k value of almost zero.

  However, with respect to polyhydroxystyrene, the etching resistance of acrylic polymer in the substrate etching is weak, and a considerable proportion of acrylic compounds must be copolymerized to lower the k value. It drops considerably. The resistance to etching 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 due to the copolymerization of acrylic compounds.

  One of the ones having higher transparency at 193 nm and higher etching resistance than a benzene ring is a naphthalene ring. Japanese Unexamined Patent Application Publication No. 2002-14474 (Patent Document 6) proposes a lower layer film having a naphthalene ring and an anthracene ring. 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 has not been achieved. I have to raise it. In addition, the n value at 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. Also in the acenaphthylene polymer shown by Unexamined-Japanese-Patent No. 2001-40293 (patent document 7), Unexamined-Japanese-Patent No. 2002-214777 (patent document 8), the n value in 193 nm is low compared with wavelength 248 nm, k value is high, Both have not reached the target value. There is a need for a lower layer film that has a high n value, a low k value, is transparent and has high etching resistance.

On the other hand, a three-layer process has been proposed in which a single-layer resist containing no silicon is formed as an upper layer, an intermediate layer containing silicon underneath, and an organic film thereunder (Non-Patent Document 5: J. Vac. Sci). Technol., 16 (6), Nov./Dec. 1979).
In general, a single-layer resist has better resolution than a silicon-containing resist, and a high-resolution single-layer resist can be used as an exposure imaging layer in a three-layer process.
As the intermediate layer, a spin-on-glass (SOG) film is used, and many SOG films have been proposed.

Here, the optimum optical constant of the lower layer film for suppressing the substrate reflection in the three-layer process is different from that in the two-layer process.
The purpose of suppressing the substrate reflection as much as possible, specifically to reduce it to 1% or less, is the same in both the two-layer process and the three-layer process, whereas the two-layer process has an antireflection effect only on the lower layer film. In the three-layer process, one or both of the intermediate layer and the lower layer can have an antireflection effect.
A silicon-containing layer material imparted with an antireflection effect is proposed in US Pat. No. 6,506,497 (Patent Document 9) and US Pat. No. 6420088 (Patent Document 10).
In general, a multilayer antireflection film has a higher antireflection effect than a single-layer antireflection film, and is widely used industrially as an antireflection film for optical materials.
By giving an antireflection effect to both the intermediate layer and the lower layer, a high antireflection effect can be obtained.
If the silicon-containing intermediate layer can be provided with a function as an antireflection film in the three-layer process, the lower layer film does not need the highest effect as the antireflection film.
As a lower layer film in the case of a three-layer process, higher etching resistance in substrate processing is required than an effect as an antireflection film.
Therefore, it is necessary to use a novolak resin having high etching resistance and containing many aromatic groups as a lower layer film for a three-layer process.

Here, FIG. 3 shows the substrate reflectivity when the k value of the intermediate layer is changed.
A sufficient antireflection effect of 1% or less can be obtained by a low value of 0.2 or less as the k value of the intermediate layer and an appropriate film thickness setting.
As an antireflection film, in order to suppress reflection to 1% or less at a film thickness of 100 nm or less, a k value of 0.2 or more is necessary (see FIG. 2), but a certain amount of reflection can be suppressed by the lower layer film. For an intermediate layer having a three-layer structure, a k value lower than 0.2 is an optimum value.

Next, FIG. 4 and FIG. 5 show the reflectance change when the thickness of the intermediate layer and the lower layer is changed when the k value of the lower layer film is 0.2 and 0.6.
The lower layer with a k value of 0.2 assumes a lower layer film optimized for a two-layer process, and the lower layer with a k value of 0.6 is close to the k value of novolak or polyhydroxystyrene at 193 nm. is there.
Although the film thickness of the lower layer film varies depending on the topography of the substrate, the film thickness of the intermediate layer hardly varies, and it is considered that the film can be applied with a set film thickness.
Here, the higher the k value of the lower layer film (in the case of 0.6), the reflection can be suppressed to 1% or less with a thinner film.
When the k value of the lower layer film is 0.2, the thickness of the intermediate layer must be increased in order to reduce the reflection to 1% or less when the film thickness is 250 nm.
Increasing the thickness of the intermediate layer is not preferable because the load on the resist of the uppermost layer is large during dry etching when the intermediate layer is processed.
In order to use the lower layer film as a thin film, not only a high k value but also a higher etching resistance is required.

  When the underlying film to be processed is a low dielectric insulating film made of porous silica, the positive resist has a problem of poisoning that causes skirting and scum in a space portion. This is considered to be caused by ammonia adsorbed on the porous silica during the substrate cleaning process using ammonia or the like, and liberated during the resist process to neutralize the resist acid generated in the exposed portion. In order to prevent the occurrence of poisoning, it has been proposed to use a polymer having an acidic group (Patent Document 11: Japanese Patent Application Laid-Open No. 2004-177666).

JP-A-6-118651 Japanese Patent Laid-Open No. 10-324748 JP-A-11-302382 JP 2002-55456 A JP-A-9-110938 JP 2002-14474 A JP 2001-40293 A JP 2002-214777 A US Pat. No. 6,506,497 US Pat. No. 6420088 JP 2004-177666 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 (2001) p50 J. et al. Vac. Sci. Technol. , 16 (6), Nov. / Dec. 1979

  The present invention has been made in view of the above circumstances, and in particular has a specific bisphenol compound having a group having a large number of carbon atoms as a lower layer film for a two-layer or three-layer resist process, and is etched more than polyhydroxystyrene and cresol novolac. An object of the present invention is to provide a material for forming a lower layer film having very excellent resistance and a pattern forming method using the material.

As a result of intensive studies to achieve the above object, the present inventor is a promising material as a lower layer film for a two-layer or three-layer resist process in which a specific bisphenol compound having a group having a large number of carbon atoms is excellent in etching resistance. As a result, they have found the present invention.
That is, the present invention is a low-layer film for a two-layer or three-layer resist process, particularly high energy rays having a wavelength of 300 nm or less, specifically, excimer lasers of 248 nm, 193 nm, 157 nm, soft X-rays of 3-20 nm, electron beams. , Which proposes a material based on a specific bisphenol compound having a group having a large number of carbon atoms, which has excellent etching resistance in X-rays, and a novolak resin condensed therewith, and has a very high dry etching resistance in substrate processing Can be obtained.
The underlayer film of the present invention is mainly applied to a three-layer process. For a two-layer process of KrF and ArF, since the k value is high, the substrate reflection becomes large, but the substrate reflectance can be suppressed to 1% or less together with the intermediate layer having an antireflection effect.
Moreover, the lower layer film-forming material of the present invention is excellent in the denseness of the film and has a high ammonia gas blocking effect, which can suppress the occurrence of poisoning.

Accordingly, the present invention provides a photoresist underlayer film forming material characterized by containing a compound having a bisphenol group represented by the following general formula (1) and a compound having a bisphenol group represented by the following general formula (2): Disclosed is a photoresist underlayer film forming material comprising a resin having a novolak-ized repeating unit.

(In the formula, R ¹ and R ² are the same or different hydrogen atoms, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or 2 to 10 carbon atoms. R ³ and R ⁴ are each a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, or a linear, branched or cyclic alkenyl group having 2 to 6 carbon atoms. , An aryl group having 6 to 10 carbon atoms, an acetal group having 2 to 6 carbon atoms, an acyl group having 2 to 6 carbon atoms, or a glycidyl group, and z is a divalent group containing an aromatic skeleton having 13 to 30 carbon atoms. A hydrocarbon group, and the divalent hydrocarbon group may be a condensed polycyclic hydrocarbon group, and the hydrocarbon group may contain a hetero atom, R ⁵ is a hydrogen atom, A linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, or an aryl having 6 to 10 carbon atoms Is a group. However,
But
Except for groups that are )
In this case, the photoresist underlayer film forming material can further contain an organic solvent, a crosslinking agent, and an acid generator.

  Further, the present invention applies the photoresist underlayer film on a substrate to be processed, applies a layer of a photoresist composition on the underlayer film, irradiates a desired region of the photoresist layer with radiation, and develops it. Provided is a pattern forming method characterized by forming a photoresist pattern by developing with a liquid, and then processing the photoresist underlayer film layer and the substrate to be processed using the photoresist pattern layer as a mask in a dry etching apparatus. . In this case, it is preferable that the photoresist composition contains a silicon atom-containing polymer, and dry etching for processing the photoresist underlayer film using the photoresist layer as a mask is performed using an etching gas mainly composed of oxygen gas.

  Further, in the present invention, the photoresist underlayer film forming material is applied on a substrate to be processed, an intermediate layer containing silicon atoms is applied on the underlayer film, and a photoresist composition is formed on the intermediate layer. Apply a layer, irradiate the required area of this photoresist layer with radiation, develop with a developer to form a photoresist pattern, and process the intermediate film layer with this photoresist pattern layer as a mask with a dry etching device Then, after the photoresist pattern layer is removed, a lower layer film layer and then a substrate to be processed are processed using the processed intermediate film layer as a mask. In this case, it is preferable to perform dry etching, in which the photoresist composition contains a polymer containing no silicon atom, and the lower layer film is processed using the intermediate layer film as a mask, using an etching gas mainly composed of oxygen gas.

The photoresist underlayer film forming material of the present invention has an extinction coefficient that can exhibit a sufficient antireflection effect at a film thickness of 200 nm or more by combining with an intermediate layer having an antireflection effect as necessary, and is used for substrate processing. Etching resistance to CF ₄ / CHF ₃ gas and Cl ₂ / BCl ₃ gas to be produced is stronger than ordinary m-cresol novolac resin and has high etching resistance. Also, the resist shape after patterning is good.

The pattern forming method of the present invention includes a specific bisphenol compound having a group having a large number of carbon atoms represented by the general formula (1) and / or a resin having a repeating unit represented by the general formula (2) obtained by novolacizing the compound. A photoresist underlayer film is applied on the substrate, a layer of a photoresist composition is applied on the underlayer film through an intermediate layer as necessary, and a desired region of the photoresist layer is irradiated with radiation, and a developer is used. A resist pattern is formed by development, and the lower layer film layer and the substrate are processed using the photoresist pattern layer as a mask with a dry etching apparatus.
(A) In addition to a specific bisphenol compound having a group having a large number of carbon atoms represented by the following general formula (1) and / or a resin having a repeating unit represented by the general formula (2) obtained by novolacizing this compound as an essential component (B) Usually contains an organic solvent, but (C) a polymer for blending in order to increase spin coating characteristics, step board embedding characteristics, film rigidity and solvent resistance,
(D) a crosslinking agent,
(E) An acid generator may also be included.

(In the formula, R ¹ and R ² are the same or different hydrogen atoms, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or 2 to 10 carbon atoms. R ³ and R ⁴ are each a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, or a linear, branched or cyclic alkenyl group having 2 to 6 carbon atoms. , An aryl group having 6 to 10 carbon atoms, an acetal group having 2 to 6 carbon atoms, an acyl group having 2 to 6 carbon atoms, or a glycidyl group, and z is a divalent group containing an aromatic skeleton having 13 to 30 carbon atoms. A hydrocarbon group, and the divalent hydrocarbon group may be a condensed polycyclic hydrocarbon group, and the hydrocarbon group may contain a hetero atom, R ⁵ is a hydrogen atom, A linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, or an aryl having 6 to 10 carbon atoms Is a group. However,
But
Except for groups that are )

In this case, specific examples of R ¹ and R ² include a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a cyclopentyl group, a hexyl group, and a cyclohexyl group. Group, alkyl group such as octyl group, aryl group such as phenyl group, tolyl group, xylyl group, vinyl group, allyl group, propenyl group, butenyl group, alkenyl group such as hexenyl group, cyclohexenyl group, etc. Specific examples of R ³ and R ⁴ include a hydrogen atom, the same alkyl group, alkenyl group, and aryl group as described above, as well as an ethoxyethyl group, a methoxymethyl group, an ethoxypropyl group, an ethoxybutyl group, a propoxyethyl group, and a butoxy group. Examples include an acetal group such as an ethyl group, an acyl group such as an acetyl group, and a glycidyl group. Specific examples of R ⁵ include a hydrogen atom, the same alkyl group as described above, and an aryl group.

Also,

Examples of such are as follows.

Specific examples of the compound represented by the general formula (1) include the following.

(In the formula, R ¹ , R ² , R ³ and R ⁴ are as described above. Preferably, R ³ and R ⁴ are a hydrogen atom or a glycidyl group, particularly a hydrogen atom.)

Among the above compounds, those in which R ³ and R ⁴ are H can be obtained by reacting phenol and the corresponding cyclic ketone according to a conventional method, and those in which R ³ and R ⁴ are glycidyl groups are those described above. Can be obtained by glycidylation of the phenolic hydroxyl group according to a conventional method. Further, in the case where R ³ and R ⁴ are an alkyl group, alkenyl group, aryl group, acetal group or acyl group, the phenolic hydroxyl group may be similarly converted to a desired group according to a conventional method.

  In the present invention, the specific bisphenol compound used for the lower layer film may be added as it is represented by the general formula (1) to form the lower layer film, or, as represented by the general formula (2), the formula (1) A resin having a repeating unit novolakized by a condensation reaction between the bisphenol compound and aldehydes may be added.

  Examples of aldehydes used here include formaldehyde, trioxane, paraformaldehyde, benzaldehyde, acetaldehyde, propylaldehyde, phenylacetaldehyde, α-phenylpropylaldehyde, β-phenylpropylaldehyde, o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p. -Hydroxybenzaldehyde, o-chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde, o-nitrobenzaldehyde, m-nitrobenzaldehyde, p-nitrobenzaldehyde, o-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, p -Ethylbenzaldehyde, pn-butylbenzaldehyde, furfural, etc. Can be mentioned. Of these, formaldehyde can be particularly preferably used.

These aldehydes can be used alone or in combination of two or more.
0.2-5 mol is preferable with respect to 1 mol of phenols, and, as for the usage-amount of the said aldehyde, More preferably, it is 0.5-2 mol.

A catalyst can also be used for the condensation reaction of phenols and aldehydes.
Specific examples include acidic catalysts such as hydrochloric acid, nitric acid, sulfuric acid, formic acid, oxalic acid, acetic acid, methanesulfonic acid, camphorsulfonic acid, tosylic acid, and trifluoromethanesulfonic acid.
The usage-amount of these acidic catalysts is 1 * 10 < ^-5 > ^-5 * 10 < ^-1 > mol with respect to 1 mol of phenols.

  Indene, hydroxyindene, benzofuran, hydroxyanthracene, acenaphthylene, biphenyl, bisphenol, trisphenol, dicyclopentadiene, tetrahydroindene, 4-vinylcyclohexene, norbornadiene, 5-vinylnorborna-2-ene, α-pinene, β-pinene In the case of a copolymerization reaction with a compound having a non-conjugated double bond such as limonene, aldehydes are not necessarily required.

As a reaction solvent in polycondensation, water, methanol, ethanol, propanol, butanol, tetrahydrofuran, dioxane or a mixed solvent thereof can be used.
These solvents are in the range of 0 to 2,000 parts with respect to 100 parts (parts by mass, the same applies hereinafter) of reaction raw materials.
Although reaction temperature can be suitably selected according to the reactivity of the reaction raw material, it is the range of 10-200 degreeC normally.

Examples of the condensation reaction method include a method in which phenols, aldehydes, and a catalyst are charged in a lump, and a method in which phenols and aldehydes are dropped in the presence of a catalyst.
After completion of the polycondensation reaction, in order to remove unreacted raw materials, catalysts, etc. existing in the system, the temperature of the reaction kettle can be raised to 130-230 ° C., and volatile matter can be removed at about 1-50 mmHg. .

  The bisphenols represented by the general formula (1) may be polymerized alone, but other phenols may be copolymerized.

  The copolymerizable phenols are phenol, o-cresol, m-cresol, p-cresol, 2,3-dimethylphenol, 2,5-dimethylphenol, 3,4-dimethylphenol, 3,5-dimethylphenol, 2,4-dimethylphenol, 2,6-dimethylphenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, 2-t-butylphenol, 3-t-butylphenol, 4-t-butylphenol, 2-phenylphenol, 3-phenylphenol, 4-phenylphenol, 3,5-diphenylphenol, 2-naphthylphenol, 3-naphthylphenol, 4-naphthylphenol, 4-tritylphenol, resorcinol, 2-methylresorcinol, 4 -Methylresorcinol 5-methylresorcinol, catechol, 4-t-butylcatechol, 2-methoxyphenol, 3-methoxyphenol, 2-propylphenol, 3-propylphenol, 4-propylphenol, 2-isopropylphenol, 3-isopropylphenol, 4 -Isopropylphenol, 2-methoxy-5-methylphenol, 2-t-butyl-5-methylphenol, pyrogallol, thymol, isothimol and the like can be mentioned.

  In addition, copolymerizable monomers can be copolymerized. Specifically, 1-naphthol, 2-naphthol, 2-methyl-1-naphthol, 4-methoxy-1-naphthol, 7-methoxy-2-naphthol And 1,5-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, dihydroxynaphthalene such as 2,6-dihydroxynaphthalene, methyl 3-hydroxy-naphthalene-2-carboxylate, indene, hydroxyindene, benzofuran, hydroxyanthracene, acenaphthylene, Biphenyl, bisphenol, trisphenol, dicyclopentadiene, tetrahydroindene, 4-vinylcyclohexene, norbornadiene, 5-vinylnorborna-2-ene, α-pinene, β-pinene, limonene, and the like. It may be a ternary or higher copolymer added with.

  The novolak resin thus obtained preferably contains 10 to 100 mol%, particularly 30 to 100 mol% of the repeating unit of the above formula (2). The content is preferably 0 to 90 mol%, particularly 0 to 70 mol%, and the content of the repeating unit based on the copolymerizable monomer is preferably 0 to 90 mol%, particularly preferably 0 to 70 mol%.

  The molecular weight in terms of polystyrene of the novolak resin is preferably a weight average molecular weight (Mw) of 1,000 to 30,000, particularly 2,000 to 20,000. The molecular weight distribution is preferably within the range of 1.2 to 7, but the crosslinking efficiency is improved by narrowing the molecular weight distribution by cutting monomer components, oligomer components or low molecular weight materials having a molecular weight (Mw) of 1,000 or less. In addition, the contamination around the baking cup can be prevented by suppressing the volatile components in the baking.

Next, a condensed aromatic or alicyclic substituent can be introduced into the ortho position with respect to the phenol of the novolak resin after condensation using an acidic catalyst.
Specific examples of the substituent that can be introduced here include the following.

  Of these, polycyclic aromatic groups such as anthracenemethyl group and pyrenemethyl group are most preferably used for 248 nm exposure. In order to improve transparency at 193 nm, those having an alicyclic structure and those having a naphthalene structure are preferably used. On the other hand, since the benzene ring has a window with improved transparency at a wavelength of 157 nm, it is necessary to increase the absorption by shifting the absorption wavelength. The furan ring has a shorter absorption than the benzene ring and slightly improves the absorption at 157 nm, but the effect is small. Naphthalene rings, anthracene rings, and pyrene rings are preferably used because their absorption increases as the absorption wavelength increases, and these aromatic rings also have an effect of improving etching resistance.

Examples of the method for introducing a substituent include a method in which an alcohol in which the substituent is bonded to a hydroxy group is introduced into the polymer after polymerization in the ortho or para position of the hydroxy group of the phenol in the presence of an acid catalyst. . As the acid catalyst, an acidic catalyst such as hydrochloric acid, nitric acid, sulfuric acid, formic acid, oxalic acid, acetic acid, methanesulfonic acid, n-butanesulfonic acid, camphorsulfonic acid, tosylic acid, trifluoromethanesulfonic acid and the like can be used.
The usage-amount of these acidic catalysts is 1 * 10 < ^-5 > ^-5 * 10 < ^-1 > mol with respect to 1 mol of phenols. The amount of the substituent introduced is in the range of 0 to 0.8 mol with respect to 1 mol of the phenol hydroxy group.

  In order to improve the transparency at 193 nm of the resin having the repeating unit of the general formula (2) of the present invention, hydrogenation can be performed. A preferable hydrogenation ratio is 80 mol% or less, particularly 60 mol% or less of the aromatic group.

  It can also be blended with other polymers. As the polymer for blending, it is mixed with the compound of the general formula (1) or the novolak resin having the repeating unit of the general formula (2) to improve the spin coating film forming property and the embedding property on the stepped substrate. What it has is suitable. A material having a high carbon density and high etching resistance is more preferably selected. Such materials include phenol, o-cresol, m-cresol, p-cresol, 2,3-dimethylphenol, 2,5-dimethylphenol, 3,4-dimethylphenol, 3,5-dimethylphenol, 2 , 4-dimethylphenol, 2,6-dimethylphenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, 2-t-butylphenol, 3-t-butylphenol, 4-t-butylphenol, 2 -Phenylphenol, 3-phenylphenol, 4-phenylphenol, 3,5-diphenylphenol, 2-naphthylphenol, 3-naphthylphenol, 4-naphthylphenol, 4-tritylphenol, resorcinol, 2-methylresorcinol, 4- Methyl resorcinol, 5 Methylresorcinol, catechol, 4-t-butylcatechol, 2-methoxyphenol, 3-methoxyphenol, 2-propylphenol, 3-propylphenol, 4-propylphenol, 2-isopropylphenol, 3-isopropylphenol, 4-isopropyl Phenol, 2-methoxy-5-methylphenol, 2-t-butyl-5-methylphenol, pyrogallol, thymol, isothimol, 4,4 '-(9H-fluorene-9-ylidene) bisphenol, 2,2'-dimethyl -4,4 '-(9H-fluorene-9-ylidene) bisphenol, 2,2'-diallyl-4,4'-(9H-fluorene-9-ylidene) bisphenol, 2,2'-difluoro-4,4 '-(9H-Fluorene-9-ylidene) bi Phenol, 2,2′-diphenyl-4,4 ′-(9H-fluorene-9-ylidene) bisphenol, 2,2′-dimethoxy-4,4 ′-(9H-fluorene-9-ylidene) bisphenol, 2, 3,2 ′, 3′-tetrahydro- (1,1 ′)-spirobiindene-6,6′-diol, 3,3,3 ′, 3′-tetramethyl-2,3,2 ′, 3 ′ -Tetrahydro- (1,1 ')-spirobiindene-6,6'-diol, 3,3,3', 3 ', 4,4'-hexamethyl-2,3,2', 3'-tetrahydro- (1,1 ′)-spirobiindene-6,6′-diol, 2,3,2 ′, 3′-tetrahydro- (1,1 ′)-spirobiindene-5,5′-diol, 5, 5′-dimethyl-3,3,3 ′, 3′-tetramethyl-2,3,2 ′, 3'-tetrahydro- (1,1 ')-spirobiindene-6,6'-diol, 1-naphthol, 2-naphthol, 2-methyl-1-naphthol, 4-methoxy-1-naphthol, 7-methoxy 2-naphthol and 1,5-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, dihydroxynaphthalene such as 2,6-dihydroxynaphthalene, methyl 3-hydroxy-naphthalene-2-carboxylate, indene, hydroxyindene, benzofuran, hydroxy Novolac resins such as anthracene, acenaphthylene, biphenyl, bisphenol, trisphenol, dicyclopentadiene, tetrahydroindene, 4-vinylcyclohexene, norbornadiene, 5-vinylnorborna-2-ene, α-pinene, β-pinene, limonene , Polyhydroxystyrene, polystyrene, polyvinyl naphthalene, polyvinyl anthracene, polyvinyl carbazole, polyindene, polyacenaphthylene, polynorbornene, polycyclodecene, polytetracyclododecene, polynortricyclene, poly (meth) acrylate and their co- A polymer is mentioned.

  The blending amount of the blending polymer is 0 to 1,000 parts, preferably 0 to 500 parts, based on 100 parts of the compound represented by the general formula (1) or (2).

  One of the performance requirements for the lower layer film including the antireflection film is that there is no intermixing with the upper layer film, for example, the silicon-containing intermediate layer and the resist film, and there is no diffusion of low molecular components into the upper layer film. [Proc. SPIE vol. 2195 (1994) p225-229]. In order to prevent these problems, a method is generally employed in which thermal crosslinking is performed by baking after spin coating of the antireflection film. Therefore, when a crosslinking agent is added as a component of the antireflection film material, a method of introducing a crosslinkable substituent into the polymer may be employed. Even in the case where no crosslinking agent is particularly added, in the case of a novolak resin having a specific unit bisphenol compound having a group having a large number of carbon atoms of formula (1) and a repeating unit of formula (2) condensed with this, 300 ° C. or more It can be crosslinked by the condensation reaction of the hydroxy group by heating.

  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 of the compound include a double bond such as an epoxy compound, a thioepoxy compound, an isocyanate compound, an azide compound, and an alkenyl ether group. These may be used as additives, but may be introduced as pendant groups in the polymer side chain. A compound containing a hydroxy group is also used as a crosslinking agent.

  Examples of the epoxy compound among the various compounds include tris (2,3-epoxypropyl) isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, triethylolethane triglycidyl ether and the like. 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, or 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, or a mixture thereof, tetramethoxyethylguanamine, tetraacyloxyguanamine, and tetramethylolguanamine. A compound in which ˜4 methylol groups are acyloxymethylated or a mixture thereof may be mentioned. Examples of the glycoluril compound include tetramethylol glycoluril, tetramethoxyglycoluril, tetramethoxymethylglycoluril, a compound in which 1 to 4 methylol groups of tetramethylolglycoluril are methoxymethylated, or a mixture thereof, and tetramethylolglycoluril methylol. Examples thereof include compounds in which 1 to 4 of the groups are acyloxymethylated or a mixture thereof. Examples of the urea compound include tetramethylol urea, tetramethoxymethyl urea, a compound in which 1 to 4 methylol groups of tetramethylol urea are methoxymethylated, a mixture thereof, tetramethoxyethyl urea, and the like.

  Examples of the 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, trimethylolpropane trivinyl ether, and the like.

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-hydroxy) (Cyclohexyl) -1-methylethyl] phenyl] ethylidene] biscyclohexanol, [1,1′-bicyclohexyl] -4,4′-diol, methylenebiscyclohexanol, decahydronaphthalene-2,6-diol, [1 , 1′-bicyclohexyl] -3,3 ′, 4,4′-tetrahydroxyl and other alcohol groups Compound, bisphenol, methylene bisphenol, 2,2′-methylene bis [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 ″ -ethylidynetris [2-methylphenol], 4,4 ′, 4 ″ -ethylidenetrisphenol, 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) tetrakisf Ol, 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-phenylenedimethylidene) tetrakisphenol, 2,4,6-tris (4-hydroxyphenylmethyl) 1,3-benzene Diol, 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-hi Droxyphenyl) 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] the hydroxy groups of the phenolic low nuclei such as may be a compound which is a glycidyl ether by epichlorohydrin as a crosslinking agent.

  The blending amount of the crosslinking agent in the present invention is 3 to 50 with respect to 100 parts of the total amount of the compound of formula (1), the resin having the repeating unit of formula (2), and the polymer for blending (hereinafter referred to as base polymer). Part is preferable, and 5 to 40 parts are particularly preferable. If it is less than 3 parts, it may cause mixing with the resist, and if it exceeds 50 parts, the antireflection effect may be reduced, or the film after crosslinking may be cracked or the etching resistance may be reduced due to a decrease in carbon density. .

  In the present invention, an acid generator for further promoting the crosslinking reaction by heat 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 the acid generator used in 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. A glyoxime derivative of the following general formula (P3):
iv. A bissulfone derivative 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 derivatives,
ix. Examples thereof include sulfonic acid ester derivatives.

Wherein 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 an aryl having 6 to 20 carbon atoms. Group, an aralkyl group having 7 to 12 carbon atoms or an aryloxoalkyl group, part or all of hydrogen atoms of these groups may be substituted by an alkoxy group, etc. R ^101b and R ^{101c May} form a ring, and in the case of forming a ring, R ^101b and R ^101c each represent an alkylene group having 1 to 6 carbon atoms, K ⁻ represents a non-nucleophilic counter ion, R ^101d , 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. In the case of forming a ring, R ^101d and R ^101e and R ^101d and R ^{10 1e} and R ^101f represent an alkylene group having 3 to 10 carbon atoms, or a heteroaromatic ring having a nitrogen atom in the formula.

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 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.

In addition, R ^101d is a heteroaromatic ring in which R ^101e , R ^101f , and R ^{101g each} have a nitrogen atom in the formula is an imidazole derivative (for example, imidazole, 4-methylimidazole, 4-methyl-2-phenyl). Imidazole 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, imidazo Lysine 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, phthalas 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.

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

(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 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, a heptyl group, and an octyl group. , Cyclopentyl group, cyclohexyl group, cyclopropylmethyl group, 4-methylcyclohexyl group, cyclohexylmethyl group and the like. R ¹⁰³ is methylene group, ethylene group, propylene group, butylene group, pentylene group, hexylene group, heptylene group, octylene group, nonylene group, 1,4-cyclohexylene group, 1,2-cyclohexylene. Group, 1,3-cyclopentylene group, 1,4-cyclooctylene group, 1,4-cyclohexanedimethylene group and the like. ^{Examples 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).

(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 for R ¹⁰⁵ and R ¹⁰⁶ 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, a heptyl group, an octyl group, Examples include 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, a nonafluorobutyl group, and the like. As the aryl group, an alkoxyphenyl group such as a phenyl group, a p-methoxyphenyl group, an m-methoxyphenyl group, an o-methoxyphenyl group, an ethoxyphenyl group, a p-tert-butoxyphenyl group, or an m-tert-butoxyphenyl group. And 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.

(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. Represents a linear or branched alkylene group.)

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.

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

(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.

  Specifically, for example, tetramethylammonium trifluoromethanesulfonate, tetramethylammonium nonafluorobutanesulfonate, triethylammonium nonafluorobutanesulfonate, pyridinium nonafluorobutanesulfonate, triethylammonium camphorsulfonate, pyridinium camphorsulfonate, nona Tetra n-butylammonium fluorobutanesulfonate, tetraphenylammonium nonafluorobutanesulfonate, tetramethylammonium p-toluenesulfonate, diphenyliodonium trifluoromethanesulfonate, phenyliodonium trifluoromethanesulfonate (p-tert-butoxyphenyl) phenyliodonium, p-Toluenesulfonic acid diphenyliodonium, p-toluenesulfonic acid ( -Tert-butoxyphenyl) phenyliodonium, triphenylsulfonium trifluoromethanesulfonate, trifluoromethanesulfonic acid (p-tert-butoxyphenyl) diphenylsulfonium, bis (p-tert-butoxyphenyl) phenylsulfonium trifluoromethanesulfonate, trifluoromethane Tris (p-tert-butoxyphenyl) sulfonium sulfonate, triphenylsulfonium p-toluenesulfonate, p-toluenesulfonic acid (p-tert-butoxyphenyl) diphenylsulfonium, bis (p-tert-butoxy) p-toluenesulfonate Phenyl) phenylsulfonium, p-toluenesulfonic acid tris (p-tert-butoxyphenyl) sulfonium, nonafluorobuta Triphenylsulfonium sulfonate, triphenylsulfonium butanesulfonate, trimethylsulfonium trifluoromethanesulfonate, trimethylsulfonium p-toluenesulfonate, cyclohexylmethyl trifluoromethanesulfonate (2-oxocyclohexyl) sulfonium, cyclohexylmethyl p-toluenesulfonate ( 2-oxocyclohexyl) sulfonium, dimethylphenylsulfonium trifluoromethanesulfonate, dimethylphenylsulfonium p-toluenesulfonate, dicyclohexylphenylsulfonium trifluoromethanesulfonate, dicyclohexylphenylsulfonium p-toluenesulfonate, trinaphthylsulfonium trifluoromethanesulfonate, trifluoro Lomethanesulfone Cyclohexylmethyl (2-oxocyclohexyl) sulfonium acid, trifluoromethanesulfonic acid (2-norbornyl) methyl (2-oxocyclohexyl) sulfonium, ethylenebis [methyl (2-oxocyclopentyl) sulfonium trifluoromethanesulfonate], 1,2 ' -Onium salts such as naphthylcarbonylmethyltetrahydrothiophenium triflate.

  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-amylsulfonyl) diazomethane, B hexylsulfonyl-1-(tert-butylsulfonyl) diazomethane, 1-cyclohexyl sulfonyl-1-(tert-amylsulfonyl) diazomethane, 1-tert-amylsulfonyl-1-(tert-butylsulfonyl) diazomethane derivatives such as diazomethane.

  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- (n-butanesulfonyl) -2- Til-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, Scan -O- (xylene sulfonyl)-.alpha.-dimethylglyoxime, bis -O- (camphorsulfonyl)-.alpha.-glyoxime derivatives such as dimethylglyoxime.

  Bissulfone derivatives such as bisnaphthylsulfonylmethane, bistrifluoromethylsulfonylmethane, bismethylsulfonylmethane, bisethylsulfonylmethane, bispropylsulfonylmethane, bisisopropylsulfonylmethane, bis-p-toluenesulfonylmethane, and bisbenzenesulfonylmethane.

  Β-ketosulfone derivatives such as 2-cyclohexylcarbonyl-2- (p-toluenesulfonyl) propane and 2-isopropylcarbonyl-2- (p-toluenesulfonyl) propane.

  Disulfone derivatives such as diphenyldisulfone derivatives and dicyclohexyldisulfone derivatives.

  Nitrobenzyl sulfonate derivatives such as 2,6-dinitrobenzyl p-toluenesulfonate and 2,4-dinitrobenzyl p-toluenesulfonate.

  Sulfonic acid ester derivatives such as 1,2,3-tris (methanesulfonyloxy) benzene, 1,2,3-tris (trifluoromethanesulfonyloxy) benzene, 1,2,3-tris (p-toluenesulfonyloxy) benzene .

  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 -Chloroethane sulfonic acid ester, N-hydroxysuccinimide benzene sulfonic acid ester, N- Droxysuccinimide-2,4,6-trimethylbenzenesulfonate, N-hydroxysuccinimide 1-naphthalenesulfonate, N-hydroxysuccinimide 2-naphthalenesulfonate, N-hydroxy-2-phenylsuccinimide methanesulfonate N-hydroxymaleimide methanesulfonic acid ester, N-hydroxymaleimide ethanesulfonic acid ester, N-hydroxy-2-phenylmaleimide methanesulfonic acid ester, N-hydroxyglutarimide methanesulfonic acid ester, N-hydroxyglutarimide benzenesulfonic acid Esters, N-hydroxyphthalimide methanesulfonate, N-hydroxyphthalimidebenzenesulfonate, N-hydroxyphthalate Imidotrifluoromethanesulfonic 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-dicarboximide p-toluenesulfonate Sulfonic acid ester derivatives of N-hydroxyimide compounds such as triphenylsulfonium trifluoromethanesulfonate, trifluoromethanesulfonic acid (p-tert-buto Xylphenyl) diphenylsulfonium, trifluoromethanesulfonic acid tris (p-tert-butoxyphenyl) sulfonium, p-toluenesulfonic acid triphenylsulfonium, p-toluenesulfonic acid (p-tert-butoxyphenyl) diphenylsulfonium, p-toluenesulfonic acid Tris (p-tert-butoxyphenyl) sulfonium, trifluoromethanesulfonic acid trinaphthylsulfonium, trifluoromethanesulfonic acid cyclohexylmethyl (2-oxocyclohexyl) sulfonium, trifluoromethanesulfonic acid (2-norbornyl) methyl (2-oxocyclohexyl) sulfonium Onium salts such as 1,2′-naphthylcarbonylmethyltetrahydrothiophenium triflate, bis (benzenes) Phonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (n-butylsulfonyl) diazomethane, bis (isobutylsulfonyl) diazomethane, bis (sec-butylsulfonyl) diazomethane, bis (n-propyl) Diazomethane derivatives such as sulfonyl) diazomethane, bis (isopropylsulfonyl) diazomethane, bis (tert-butylsulfonyl) diazomethane, bis-O- (p-toluenesulfonyl) -α-dimethylglyoxime, bis-O- (n-butanesulfonyl) ) -Α-dimethylglyoxime and other glyoxime derivatives, bissulfone derivatives such as bisnaphthylsulfonylmethane, N-hydroxysuccinimide methanesulfonate, N-hydroxy Succinimide trifluoromethanesulfonic acid ester, N-hydroxysuccinimide 1-propanesulfonic acid ester, N-hydroxysuccinimide 2-propanesulfonic acid ester, N-hydroxysuccinimide 1-pentanesulfonic acid ester, N-hydroxysuccinimide p-toluenesulfonic acid ester , N-hydroxynaphthalimide methanesulfonic acid ester, N-hydroxynaphthalimide benzenesulfonic acid ester, and other sulfonic acid ester derivatives of N-hydroxyimide compounds are 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 lower layer film-forming material of the present invention can be blended with a basic compound for improving storage stability.
As a basic compound, it plays the role of the quencher with respect to an acid in order to prevent the acid which generate | occur | produced in trace amount from the acid generator to advance a crosslinking reaction.
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 (for example, 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 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 preferably 0.001 to 2 parts, particularly 0.01 to 1 part, relative to 100 parts of the base polymer. When the blending amount is less than 0.001 part, there is no blending effect, and when it exceeds 2 parts, all of the acid generated by heat may be trapped and crosslinking may not occur.

  The organic solvent that can be used in the lower layer film-forming material of the present invention is not particularly limited as long as the base polymer, the acid generator, the cross-linking agent, and other additives can be dissolved. 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. In the present invention, among these organic solvents, diethylene glycol dimethyl ether, 1-ethoxy-2-propanol, ethyl lactate, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether and a mixed solvent thereof are preferably used.

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

The underlayer film of the present invention can be produced on a substrate to be processed by a spin coating method or the like, similar to a photoresist composition. After spin coating, it is desirable to evaporate the solvent and bake to accelerate the crosslinking reaction in order to prevent mixing with the upper resist film. 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 this lower layer film is appropriately selected, it is preferably 30 to 20,000 nm, particularly 50 to 15,000 nm. After forming the lower layer film, a silicon-containing resist layer is formed thereon in the case of a two-layer process, and a silicon-containing intermediate layer is formed thereon in the case of a three-layer process, and a single-layer resist layer not containing silicon is formed thereon. .
In this case, a well-known thing can be used as a photoresist composition for forming these resist layers.

  As a silicon-containing resist composition for a two-layer process, a silicon atom-containing polymer such as a polysilsesquioxane derivative or a vinylsilane derivative is used as a base polymer from the viewpoint of oxygen gas etching resistance, and further an organic solvent, an acid generator If necessary, a positive photoresist composition containing a basic compound or the like is used. In addition, as a silicon atom containing polymer, the well-known polymer used for this kind of resist composition can be used.

  A polysilsesquioxane-based intermediate layer is preferably used as the silicon-containing intermediate layer for the three-layer process. By providing the intermediate layer with an effect as an antireflection film, reflection can be suppressed.

  Especially for 193 nm exposure, if a material with many aromatic groups and high substrate etching resistance is used as the lower layer film, the k value increases and the substrate reflection increases, but the substrate reflection is suppressed by suppressing the reflection in the intermediate layer. It can be made 0.5% or less.

  As an intermediate layer having an antireflection effect, an anthracenyl group is used for exposure at 248 nm and 157 nm, a light-absorbing group having a phenyl group or a silicon-silicon bond is pendant for exposure at 193 nm, and polysilsesquioxy which is crosslinked with acid or heat. Sun is preferably used.

  In addition, an intermediate layer formed by a chemical vapor deposition (CVD) method can also be used. A SiON film is known as an intermediate layer having a high effect as an antireflection film produced by a CVD method. The formation of the intermediate layer by spin coating is simpler and more cost-effective than CVD. The upper layer resist composition in the three-layer process may be either a positive type or a negative type, and the same one as a commonly used single layer resist composition can be used.

When forming a resist layer with the said photoresist composition, a spin coat method is used preferably similarly to the case where the said lower layer film is formed. Pre-baking is performed after spin-coating the resist composition, and a range of 10 to 300 seconds at 80 to 180 ° C. is preferable. Thereafter, exposure is performed according to a conventional method, post-exposure baking (PEB), and development is performed to obtain a resist pattern. The thickness of the resist film is not particularly limited, but is preferably 30 to 500 nm, particularly 50 to 400 nm.
Examples of the exposure light include high energy rays having a wavelength of 300 nm or less, specifically, excimer lasers of 248 nm, 193 nm, and 157 nm, soft X-rays of 3 to 20 nm, electron beams, and X-rays.

Next, etching is performed using the obtained resist pattern as a mask. The lower layer film etching in the two-layer process is performed using oxygen gas. In addition to oxygen gas, it is also possible to add inert gases such as He and Ar, and CO, CO ₂ , NH ₃ , SO ₂ , N ₂ , NO _{2 and} H ₂ gases without using oxygen gas. Etching can be performed using only CO, CO ₂ , NH ₃ , SO ₂ , N ₂ , NO _{2, and} H ₂ gas. In particular, the latter gas is used for side wall protection for preventing undercut of the pattern side wall. In the etching of the intermediate layer in the three-layer process, the intermediate layer is processed by using a fluorocarbon gas with the resist pattern as a mask. Next, the oxygen gas etching is performed, and the lower layer film is processed using the intermediate layer pattern as a mask.

The next substrate to be processed can also be etched by a conventional method. For example, if the substrate is SiO ₂ or SiN, etching mainly using a chlorofluorocarbon gas, and if p-Si, Al, or W is chlorine or bromine, Etching is mainly performed. When the substrate processing is etched with chlorofluorocarbon gas, the silicon-containing resist in the two-layer resist process and the silicon-containing intermediate layer in the three-layer process are peeled off simultaneously with the substrate processing. When the substrate is etched with a chlorine-based or bromine-based gas, the silicon-containing resist or the silicon-containing intermediate layer needs to be removed by dry etching using a chlorofluorocarbon-based gas after the substrate is processed.

The underlayer film of the present invention is characterized by excellent etching resistance of these substrates to be processed.
The substrate to be processed is formed on the substrate. There is no particular limitation on the substrate, and Si, α-Si, p-Si, SiO ₂ , SiN, SiON, W, TiN, Al, etc. may be made of a material different from the film to be processed (substrate to be processed). Used. Various low-k films such as Si, SiO ₂ , SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, Al-Si, and their stopper films are used as the work film. Usually, it can be formed to a thickness of 50 to 10,000 nm, particularly 100 to 5,000 nm.

  In the pattern forming method of the present invention, the photoresist underlayer film is thus applied on the substrate, and a layer of the photoresist composition is applied on the underlayer film through an intermediate layer as necessary. Radiation is applied to the required area, developed with a developing solution to form a resist pattern, and the lower layer film layer and the substrate are processed using the photoresist pattern layer as a mask with a dry etching apparatus. More specifically, an example of the three-layer resist processing process is as follows.

In the case of the two-layer resist processing process, as shown in FIG. 6A, the lower layer film 3 is formed on the substrate to be processed (processed film) 2 stacked on the substrate 1 using the lower layer film forming material. A photoresist layer 4 made of a photoresist composition, in particular, a photoresist composition based on a silicon atom-containing polymer is formed thereon, and then a desired portion 5 of the photoresist layer 4 is exposed through a photomask. [FIG. 6B], PEB, and development to form a photoresist pattern layer 4a [FIG. 6C].
Thereafter, the base layer 3 is subjected to oxygen plasma etching using the photoresist pattern layer 4a as a mask [FIG. 6D], and after further removal of the photoresist pattern layer, the substrate 2 to be processed is etched [FIG. E)].

  On the other hand, in the case of the three-layer resist processing process, as shown in FIG. 7A, as in the case of the two-layer resist processing process, the lower layer film 3 is formed on the substrate 2 to be processed stacked on the substrate 1. After the formation, a silicon-containing intermediate layer 6 is formed, and a single-layer photoresist layer 7 is formed thereon.

  Next, as shown in FIG. 7B, the desired portion 8 of the photoresist layer 7 is exposed and subjected to PEB development to form a photoresist pattern layer 7a [FIG. 7C]. Using this photoresist pattern layer 7a as a mask, the intermediate layer 6 is etched using a CF-based gas [FIG. 7D], and after removing the photoresist pattern layer, the processed intermediate layer 6a is used as a mask. The base film 3 is subjected to oxygen plasma etching [FIG. 7E], and the processed substrate 2 is further etched after the processing intermediate layer 6a is removed [FIG. 7F].

EXAMPLES Hereinafter, although a synthesis example, an Example, and a comparative example are shown and this invention is demonstrated concretely, this invention is not limited by these description.
In addition, the measuring method of molecular weight was specifically performed by the following method.
The polystyrene equivalent weight average molecular weight (Mw) and number average molecular weight (Mn) were determined by gel permeation chromatography (GPC), and the degree of dispersion (Mw / Mn) was determined.

[Synthesis Example 1]
To a 300 ml flask, 200 g of Compound 1 shown below, 75 g of a 37% formalin aqueous solution, and 5 g of oxalic acid were added and reacted at 100 ° C. for 24 hours with stirring. After the reaction, it is dissolved in 500 ml of methyl isobutyl ketone, the catalyst and metal impurities are removed by washing with sufficient water, the solvent is removed under reduced pressure, the pressure is reduced to 150 ° C. and 2 mmHg, water and unreacted monomers are removed, and the polymer represented by the following formula 163 g of 1 was obtained.
The molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the ratio in the polymer was determined by ¹ H-NMR analysis as follows.
Mw = 8,000, Mw / Mn = 4.30

[Synthesis Example 2]
300 ml flask 200 g of the compound 2 shown below, 37% formalin aqueous solution 75 g, and oxalic acid 5 g were added and reacted at 100 ° C. for 24 hours with stirring. After the reaction, it is dissolved in 500 ml of methyl isobutyl ketone, the catalyst and metal impurities are removed by washing with sufficient water, the solvent is removed under reduced pressure, the pressure is reduced to 150 ° C. and 2 mmHg, water and unreacted monomers are removed, and the polymer represented by the following formula 188 g of 2 was obtained.
The molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the ratio in the polymer was determined by ¹ H-NMR analysis as follows.
Mw = 9,500, Mw / Mn = 4.80

As specific bisphenol compounds having a group having a large number of carbon atoms, the following compounds 1 to 6 were used.

The base polymer 3 for blending is indene-hydroxystyrene obtained by cationic polymerization, the polymer 4 is acenaphthylene-hydroxystyrene obtained by cationic polymerization, and the polymer 5 is 4,4 ′-(9H-fluorene-9- A resin in which ylidene) bisphenol was novolaked with formalin was used. The structures, polymerization ratios, and molecular weights of the blending polymers 3 to 5 are shown below.

  As Comparative Example Polymer 1, 4-hydroxystyrene: 2-methacrylic acid-1-anthracenemethyl = 56: 44 obtained by radical polymerization, weight average molecular weight (Mw) = 14,400, molecular weight distribution (Mw / Mn) = 1.77, mw-cresol novolak resin with Mw = 8,800, Mw / Mn = 4.5 as polymer 2 for comparative example, Mw = 9,200, Mw / Mn = 1 as polymer 3 for comparative example .05 polyhydroxystyrene was used.

[Examples and Comparative Examples]
As shown in Table 1, the resin shown by polymers 1 and 2, the resin shown by polymers 3 to 5 for blending, the resin shown by polymers 1 to 3 for comparative examples, and a specific bisphenol compound having a group having a large number of carbon atoms 1 to 6, an ArF silicon-containing intermediate layer polymer 1, an acid generator represented by AG1, and a crosslinking agent represented by CR1 and 2, in a solvent containing 0.1% by mass of FC-430 (manufactured by Sumitomo 3M Ltd.) The lower layer film solution and the intermediate layer film solution were respectively prepared by dissolving them in the ratios shown in Table 1 and filtering through a 0.1 μm fluororesin filter.

  As an upper layer resist material, a resin, an acid generator, and a basic compound having the composition shown in Table 2 are dissolved in a solvent containing 0.1% by mass of FC-430 (manufactured by Sumitomo 3M Limited), and 0.1 μm It was prepared by filtering with a fluororesin filter.

  Underlayer film forming materials are respectively applied on a silicon substrate, UDL-1 and 2 are baked at 300 ° C. for 60 seconds, UDL-3 to 14 and comparative examples UDL-1 to 3 are baked at 200 ° C. for 60 seconds, respectively. As a lower layer film, a lower layer film having a film thickness of 300 nm (hereinafter referred to as UDL-1 to 14 and abbreviated as comparative examples UDL-1 to UDL-1) is formed. For 60 seconds to form a 100 nm thick silicon-containing film (hereinafter abbreviated as SOG1). A. The refractive index (n, k) of UDL-1-14, SOG1, and comparative example UDL-1-3 at a wavelength of 193 nm was determined by a Woollam Incident Angle Ellipsometer (VASE), and the results are shown in Table 1. It was.

PGMEA: Propylene glycol monomethyl ether acetate

The lower layer film forming material solution (UDL-1 to 14, Comparative Example UDL-1 to UDL-1 to 3) was applied on a 300 nm thick SiO ₂ substrate, and UDL-1 and UDL-1 were heated at 300 ° C. for 60 seconds. 3 to 14 were baked at 200 ° C. for 60 seconds to form an underlayer film having a thickness of 200 nm.
A silicon-containing intermediate layer material solution SOG1 is applied thereon and baked at 200 ° C. for 60 seconds to form a 70 nm-thick intermediate layer. Further, an ArF SL resist solution is applied and baked at 130 ° C. for 60 seconds. A photoresist layer having a thickness of 150 nm was formed.
Next, exposure was performed with an ArF exposure apparatus (manufactured by Nikon Corporation; S307E, NA 0.85, σ 0.93, 4/5 ring illumination, 6% transmittance halftone phase shift mask), and baked at 110 ° C. for 60 seconds ( PEB) and developed with an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution for 60 seconds to obtain a positive pattern. A pattern shape of 0.08 μmL / S of the obtained pattern was observed. The results are shown in Table 5.

Next, a dry etching resistance test was performed. First, the same lower layer films (UDL-1 to 14 and Comparative Examples UDL-1 to UDL-1 to 3) used for the refractive index measurement were prepared, and these lower layer films were etched with CF ₄ / CHF ₃ gas as an etching test. The test was performed under the following conditions (1). In this case, the difference in film thickness between the lower layer film and the resist before and after etching was measured using a dry etching apparatus TE-8500P manufactured by Tokyo Electron Limited. The results are shown in Table 3.
(1) Etching test with CF ₄ / CHF ₃ gas 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

Further, using the lower layer films (UDL-1 to 14, Comparative Examples UDL-1 to UDL-1), an etching test with a Cl ₂ / BCl ₃ gas was performed under the condition (2) below. In this case, the thickness difference of the polymer film before and after etching was determined using a dry etching apparatus L-507D-L manufactured by Nidec Anelva Corporation. The results are shown in Table 4.
(2) Etching test with Cl ₂ / BCl ₃ gas 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 resist pattern obtained after the ArF exposure and development was transferred to the SOG film under the following conditions. Etching conditions (3) are as shown below.
Chamber pressure 40.0Pa
RF power 1,000W
Gap 9mm
CHF ₃ gas flow rate 20ml / min
CF ₄ gas flow rate 60ml / min
Ar gas flow rate 200ml / min
Time 30sec
Further, the pattern transferred to the SOG film was transferred to the lower layer film by etching mainly composed of the following oxygen gas. Etching conditions (4) are as shown below.
Chamber pressure 60.0Pa
RF power 600W
Ar gas flow rate 40ml / min
O ₂ gas flow rate 60ml / min
Gap 9mm
Time 20sec
Finally, the SiO ₂ substrate was processed using the lower layer film pattern as a mask under the etching conditions shown in (1).

  The cross section of the pattern was observed with an electron microscope (S-4700) manufactured by Hitachi, Ltd., and the shapes were compared and summarized in Table 5.

As shown in Tables 3 and 4, the etching rate of the CF ₄ / CHF ₃ gas and Cl ₂ / BCl ₃ gas of the lower layer film of the present invention is sufficiently slower than that of the novolac resin polyhydroxystyrene. Furthermore, as shown in Table 5, it was recognized that the resist shape after development, the shape of the lower layer film after the oxygen etching and the substrate processing etching were also good.

It is a graph which shows the relationship between the film thickness of the lower layer film | membrane which changed the n value in the range of 1.0-2.0, and the board | substrate reflectance with the lower layer film refractive index k value in 0.3 layer being fixed. It is a graph which shows the relationship between the film thickness of the lower layer film | membrane which changed the k value in the range of 0-1.0, and the board | substrate reflectance with the lower layer film refractive index n value in 2 layer process being 1.5 fixed. In the three-layer process, the refractive index n value of the lower layer film is 1.5, the k value is 0.6, the film thickness is fixed to 500 nm, the n value of the intermediate layer is 1.5, the k value is 0 to 0.4, and the film thickness is It is a graph which shows the relationship of a board | substrate reflectance when it changes in the range of 0-400 nm. In the three-layer process, the refractive index n value of the lower layer film is 1.5, the k value is 0.2, the n value of the intermediate layer is 1.5, and the k value is fixed at 0.1 to change the film thickness of the lower layer and the intermediate layer. It is a graph which shows the relationship of the board | substrate reflectance at the time. In the three-layer process, the refractive index n value of the lower layer film is 1.5, the k value is 0.6, the n value of the intermediate layer is 1.5, and the k value is fixed at 0.1 to change the film thickness of the lower layer and the intermediate layer. It is a graph which shows the relationship of the substrate reflectance at the time. It is explanatory drawing of a two-layer resist processing process. It is explanatory drawing of a 3 layer resist processing process.

Explanation of symbols

1 substrate 2 substrate to be processed (film to be processed)
3 Underlayer film 4, 7 Photoresist layer 5, 8 Exposed part 6 Intermediate layer

Claims (9)

A photoresist underlayer film forming material comprising a compound having a bisphenol group represented by the following general formula (1).
(In the formula, R ¹ and R ² are the same or different hydrogen atoms, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or 2 to 10 carbon atoms. R ³ and R ⁴ are each a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, or a linear, branched or cyclic alkenyl group having 2 to 6 carbon atoms. , An aryl group having 6 to 10 carbon atoms, an acetal group having 2 to 6 carbon atoms, an acyl group having 2 to 6 carbon atoms, or a glycidyl group, and z is a divalent group containing an aromatic skeleton having 13 to 30 carbon atoms. A hydrocarbon group, and the divalent hydrocarbon group may be a condensed polycyclic hydrocarbon group, and the hydrocarbon group may contain a heteroatom , provided that
But
Except for groups that are ) A photoresist underlayer film forming material comprising a resin having a repeating unit obtained by novolacizing a compound having a bisphenol group represented by the following general formula (2).

(In the formula, R ¹ and R ² are the same or different hydrogen atoms, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or 2 to 10 carbon atoms. R ³ and R ⁴ are each a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, or a linear, branched or cyclic alkenyl group having 2 to 6 carbon atoms. , An aryl group having 6 to 10 carbon atoms, an acetal group having 2 to 6 carbon atoms, an acyl group having 2 to 6 carbon atoms, or a glycidyl group, and z is a divalent group containing an aromatic skeleton having 13 to 30 carbon atoms. A hydrocarbon group, and the divalent hydrocarbon group may be a condensed polycyclic hydrocarbon group, and the hydrocarbon group may contain a hetero atom, R ⁵ is a hydrogen atom, A linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, or an aryl having 6 to 10 carbon atoms Is a group. However,
But
Except for groups that are ) The material for forming a photoresist underlayer according to claim 1, wherein is a group selected from the following groups.

The material for forming a photoresist underlayer film according to any one of claims 1 to 3, further comprising an organic solvent. The material for forming a photoresist underlayer film according to any one of claims 1 to 4, further comprising a crosslinking agent and an acid generator. A photoresist underlayer film according to any one of claims 1 to 5 is applied on a substrate to be processed, a layer of a photoresist composition is applied on the underlayer film, and radiation is applied to a desired region of the photoresist layer. And developing with a developing solution to form a photoresist pattern, and then processing the photoresist underlayer film layer and the substrate to be processed using the photoresist pattern layer as a mask in a dry etching apparatus. Forming method. 7. The pattern forming method according to claim 6, wherein the photoresist composition contains a silicon atom-containing polymer, and dry etching for processing the photoresist underlayer film using the photoresist layer as a mask is performed using an etching gas mainly composed of oxygen gas. . The photo-resist underlayer film forming composition of any one of claims 1 to 5 is applied on a substrate to be processed, applying an intermediate layer containing a silicon atom on the lower layer film, on the intermediate layer Apply a layer of the photoresist composition, irradiate the desired area of the photoresist layer with radiation, develop with a developer to form a photoresist pattern, and use the photoresist pattern layer as a mask with a dry etching apparatus A pattern forming method comprising processing a film layer, removing a photoresist pattern layer, and then processing a lower film layer and then a substrate to be processed using the processed intermediate film layer as a mask. 9. The pattern forming method according to claim 8, wherein the photoresist composition contains a polymer containing no silicon atom, and dry etching for processing the lower layer film using the intermediate layer film as a mask is performed using an etching gas mainly composed of oxygen gas. .