JP4252872B2 - Resist underlayer film material and pattern forming method - Google Patents

Description

The present invention relates to a resist underlayer film material useful in a multilayer resist process used for microfabrication in a manufacturing process of a semiconductor element or the like, and in particular, far ultraviolet light, KrF excimer laser light (248 nm), ArF excimer laser light (193 nm), F Resist underlayer film material of multilayer resist film suitable for exposure with ₂ laser light (157 nm), Kr ₂ laser light (146 nm), Ar ₂ laser light (126 nm), soft X-ray, electron beam, ion beam, X-ray, etc. About. Furthermore, this invention relates to the method of forming a pattern in a board | substrate by lithography using this.

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

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

On the other hand, conventionally, it is known that a multilayer resist process such as a two-layer resist process or a three-layer resist process is excellent for forming a high aspect ratio pattern on a stepped substrate.
In the two-layer resist process, in order to develop the two-layer resist film with a general alkali developer, a polymeric silicone compound having a hydrophilic group such as a hydroxy group or a carboxyl group as a base resin for the resist upper layer film material Is preferred.

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

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

As the resist underlayer film used in the two-layer resist process, for example, a hydrocarbon compound that can be etched with oxygen gas is suitable, and furthermore, it serves as a mask when etching the underlying substrate, and therefore has high etching resistance. desirable. When the etching of the resist lower layer film using the resist upper layer film as a mask is performed by oxygen gas etching, it is desirable that the resist lower layer film is composed only of hydrocarbons not containing silicon atoms. In addition, in order to improve the line width controllability of the resist upper layer film containing silicon atoms and to reduce the pattern sidewall irregularities and pattern collapse due to standing waves, the resist underlayer film also functions as an antireflection film. Specifically, it is desirable that the reflectance from the lower layer film into the resist upper layer film can be suppressed to 1% or less.
The reflectivity is 1% by setting a material having an optimal refractive index (real part of refractive index) n value and extinction coefficient (imaginary part of refractive index) k value of the resist underlayer film to an appropriate film thickness. The following can be suppressed.

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

  In FIG. 2, the n value of the resist underlayer film is fixed to 1.5, the vertical axis is the k value, the horizontal axis is the film thickness, the k value is in the range of 0 to 0.8, and the film thickness is in the range of 0 to 500 nm. The change in reflectivity when fluctuated with is shown. As shown in FIG. 2, when a resist underlayer film for a two-layer resist process having a film thickness of 300 nm or more is assumed, it is possible to reduce the reflectance to 1% or less in the range of k value from 0.24 to 0.15. I know that there is. On the other hand, the optimum k value of an 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 a resist underlayer film for a two layer resist process of 300 nm or more. . Thus, it has been shown that a resist underlayer film for a two-layer resist process requires a lower k value, that is, a more transparent resist underlayer film.

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

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

Therefore, a naphthalene ring is one of those having higher transparency at a wavelength of 193 nm and higher etching resistance than a benzene ring, and it has been proposed to use this. For example, a resist underlayer film having a naphthalene ring or an anthracene ring has been proposed (see, for example, Patent Document 6). However, the k value of naphthol co-condensed novolak resin and polyvinyl naphthalene resin is between 0.3 and 0.4, and the target transparency of 0.1 to 0.3 is not achieved, and the desired antireflection In order to obtain an effect, the transparency must be further increased. In addition, the n value at a wavelength of 193 nm of the naphthol co-condensed novolak resin and the polyvinyl naphthalene resin is low, and as a result of measurement by the present inventors, it is 1.4 for the naphthol co-condensed novolak resin and 1.2 for the polyvinyl naphthalene resin. Yes, the target range has not been achieved. Furthermore, although an acenaphthylene polymer has been proposed, this has a lower n value at a wavelength of 193 nm than that of a wavelength of 248 nm, a high k value, and both have not reached the target value (see, for example, Patent Documents 7 and 8). ).
Thus, in the two-layer resist process, there is a demand for a resist underlayer film having a high n value, a low k value, transparency and high etching resistance.

On the other hand, a three-layer resist process is proposed in which a single-layer resist containing no silicon is formed as a resist upper layer film, a resist intermediate layer film containing silicon underneath, and a resist underlayer film as an organic film thereunder. For example, refer nonpatent literature 5.).
In general, a single-layer resist not containing silicon, which is a resist upper layer film of a three-layer resist process, has a higher resolution than a silicon-containing resist, which is a resist upper layer film of a two-layer resist process. Then, a high resolution single layer resist can be used as the exposure imaging layer.
As the resist intermediate layer film, a spin-on-glass (SOG) film is used, and many SOG films have been proposed.

Here, the optimal optical constant (n value, k value) of the resist underlayer film for suppressing substrate reflection in the three-layer resist process is different from that in the two-layer resist process. The purpose of suppressing the substrate reflection as much as possible and specifically reducing the substrate reflectivity to 1% or less is the same in the two-layer resist process and the three-layer resist process, but the two-layer resist process is applied only to the resist underlayer film. In contrast to providing an antireflection effect, the three-layer resist process can provide an antireflection effect on one or both of the resist intermediate layer film and the resist underlayer film.
For example, a silicon-containing resist intermediate layer film having an antireflection effect has been proposed (see, for example, Patent Documents 9 and 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. In the three-layer resist process, a high antireflection effect can be obtained by imparting an antireflection effect to both the resist intermediate layer film and the resist underlayer film. That is, if the silicon-containing resist intermediate layer film can have a function as an antireflection film in the three-layer resist process, the resist underlayer film does not need to have the highest effect as an antireflection film. In particular, the resist underlayer film in the case of a three-layer resist process is required to have higher etching resistance in substrate processing than the effect as an antireflection film. Therefore, it is preferable to use a novolak resin having high etching resistance and containing a large amount of aromatic groups as a resist underlayer film for a three-layer resist process.

Here, in FIG. 3, the n value of the resist underlayer film is fixed to 1.5, the k value is fixed to 0.6, the film thickness is fixed to 500 nm, the n value of the resist intermediate film is set to 1.5, and the k value is set to 0. The change of the substrate reflectance when the film thickness is changed in the range of -0.4 and the film thickness in the range of 0-400 nm is shown.
It can be seen from FIG. 3 that a sufficient antireflection effect with a substrate reflectance of 1% or less can be obtained by setting the k value of the resist intermediate layer film to a low value of 0.2 or less and an appropriate film thickness. In order to suppress the substrate reflectivity to 1% with a film thickness of 100 nm or less as a normal antireflection film, the k value needs to be 0.2 or more (see FIG. 2). As an intermediate layer having a three-layer structure that can be suppressed, a k value lower than 0.2 is an optimum value.

Next, changes in the substrate reflectivity when the resist intermediate layer film and the resist underlayer film are changed in thickness when the k value of the resist underlayer film is 0.2 and 0.6 are shown in FIGS. Shown in The resist underlayer film having a k value of 0.2 is assumed to be a resist underlayer film optimized for a two-layer resist process, and the resist underlayer film having a k value of 0.6 is novolak or polyhydroxystyrene at a wavelength of 193 nm. The value is close to the k value. Although the film thickness of the resist underlayer film varies depending on the topography of the substrate, the film thickness of the intermediate layer hardly varies, and it is considered that the resist can be applied with a set film thickness.
Here, the higher the k value of the resist underlayer film (in the case of 0.6), the optimum substrate thickness such as 50 nm, 110 nm, 170 nm, etc. is selected, thereby reducing the substrate reflectivity by 1%. The following can be suppressed. When the k value of the resist underlayer film is 0.2, the film thickness of 250 nm has almost no limit on the film thickness of the intermediate layer in order to make the substrate reflectivity 1% or less. From the viewpoint of widening the range of selection of the thickness of the substrate reflection suppression intermediate layer, the k value of the resist underlayer film is preferably 0.2, but the material having the k values of 0.2 and 0.6 at a wavelength of 193 nm In general, a material having a k value of 0.6 has a higher etching resistance when processing the substrate. In addition, the resist underlayer film having a k value of 0.6 can have a reflectance of 1% or less even when the thickness is reduced to 100 nm or less depending on the optimum film thickness of the intermediate layer. Thinning is possible.
As described above, in the three-layer resist process, the etching resistance during the substrate etching is higher, and the k value can be adjusted to the optimum range, whereby the resist intermediate layer film is thin. However, there is a demand for a resist underlayer film that can keep the substrate reflectance low.

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. 3,304,417 US Pat. No. 6420088 SPIE vol. 1925 (1993) p377 SPIE vol. 3333 (1998) p62 J. et al. Photopolymer Sci. and Technol. Vol. 9 No. 3 (1996) p435-446 SPIE Vol. 4345 p50 (2001) J. et al. Vac. Sci. Technol. , 16 (6), Nov. / Dec. 1979

  The present invention has been made in view of such problems, and is a resist underlayer film material containing a novolak resin, and particularly a resist intermediate layer film having an antireflection effect alone or with respect to exposure at a short wavelength. In combination with the above, an excellent antireflection effect is exhibited, that is, it has an optimum n value and k value, and is more excellent in etching resistance during substrate etching than polyhydroxystyrene, cresol novolak, etc. It is an object to provide a resist underlayer material suitable for use in a layer or three-layer resist process.

（ここで上記一般式（１）中、Ｒ^１は炭素数１〜４の直鎖状、分岐状のアルキレン基であり、Ｒ^２は炭素数４〜２０の環状のアルキル基又は炭素数６〜３０のアリール基であり、ヒドロキシ基、エーテル基、チオエーテル基、エステル基のいずれか１以上の基を含んでいてもよい。） The present invention has been made to solve the above problems, and is a resist underlayer film material for a multilayer resist film used in lithography, and includes at least a novolac resin. The novolac resin has the following general formula: (1) are those having repeating units substituted with a group represented by that provide a resist underlayer film material characterized.

(Here, in the general formula (1), R ¹ is a linear or branched alkylene group having 1 to 4 carbon atoms, and R ² is a cyclic alkyl group having 4 to 20 carbon atoms or 6 to 6 carbon atoms. 30 aryl groups, which may contain one or more of a hydroxy group, an ether group, a thioether group, and an ester group.)

（ここで上記一般式（２）中、Ｒ^１、Ｒ^２は前述の通りである。Ｒ^３、Ｒ^４、Ｒ^５はヒドロキシ基、炭素数１〜１０の直鎖状、分岐状、環状のアルコキシ基、グリシジルエーテル基、水素原子、炭素数１〜１０のアルキル基、炭素数６〜２０のアリール基、炭素数１〜１０のヒドロキシ基含有のアルキル基、炭素数１〜１０のアシル基のいずれかであり、Ｒ^３、Ｒ^４、Ｒ^５の内少なくとも一つがヒドロキシ基、炭素数１〜１０の直鎖状、分岐状、環状のアルコキシ基、グリシジルエーテル基のいずれかである。Ｒ^６は水素原子、炭素数１〜６の直鎖状、分岐状、環状のアルキル基、炭素数２〜６の直鎖状、分岐状、環状のアルケニル基、炭素数６〜１０のアリール基のいずれかである。） In this case, as the resist underlayer film material, for example, the novolac resin is Ru include those having a repeating unit represented by the following general formula (2).

(In the general formula (2), R ¹ and R ² are as described above. R ³ , R ⁴ , and R ⁵ are hydroxy groups, linear, branched, and cyclic having 1 to 10 carbon atoms. An alkoxy group, a glycidyl ether group, a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkyl group containing a hydroxy group having 1 to 10 carbon atoms, and an acyl group having 1 to 10 carbon atoms. are ^either, R ^3, R 4, at least one hydroxy group of ^{R 5,} a straight, branched, cyclic alkoxy group, or a glycidyl ether group .R ⁶ Is any of a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, a linear, branched or cyclic alkenyl group having 2 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms. )

Thus, it contains at least a novolak resin, and the novolak resin has a repeating unit substituted with a group represented by the following general formula (1), for example, represented by the general formula (2). Resist underlayer film materials that have repeating units exhibit excellent antireflection effect when used alone or in combination with a resist intermediate layer film having antireflection effect, particularly for exposure at short wavelengths, that is, optimal N value, k value, and excellent etching resistance at the time of substrate etching.
Moreover, if such a resist underlayer film material is used, the resist pattern shape after development will be good.

Then, the resist underlayer film material of the present invention, further crosslinking agents, acid generators, have the preferred to contain those of any one or more of the organic solvents.

  As described above, the resist underlayer film material of the present invention further contains any one or more of a crosslinking agent, an acid generator, and an organic solvent. The crosslinking reaction in the resist underlayer film can be promoted, and the coating property to the substrate or the like can be improved. Therefore, the resist underlayer film formed from such a material has good film thickness uniformity, and there is little risk of intermixing with the resist upper layer film or the resist intermediate layer film, and diffusion of low molecular components to the resist upper layer film, etc. Will be less.

Furthermore, the present invention is a method of forming a pattern on a substrate by lithography, wherein at least a resist underlayer film is formed on the substrate using the resist underlayer film material of the present invention, and a photoresist is formed on the underlayer film. A resist upper layer film of the composition is formed to form a two-layer resist film, the pattern circuit region of the two-layer resist film is exposed, and then developed with a developer to form a resist pattern on the resist upper layer film. A resist underlayer film formed by etching the resist underlayer film, and the substrate is etched using at least the resist underlayer film formed with the mask as a mask to form a pattern on the substrate that provides a method for forming.

  As described above, the resist underlayer film formed using the resist underlayer film material of the present invention can sufficiently suppress the substrate reflection, and can be excellent in etching resistance at the time of substrate etching. If used as a resist underlayer film, a pattern can be formed on the substrate with high accuracy.

In this case, as the resist upper layer film, using a material obtained by containing a silicon atom in the base resin, the etching of the lower layer film using the resist upper layer film as a mask, Ru can be performed oxygen gas in the dry etching mainly.

  The resist underlayer film formed from the resist underlayer film material of the present invention uses a base resin containing silicon atoms as a resist upper layer film, and mainly etches the lower layer film using the resist upper layer film as a mask. It is suitable for transferring the resist pattern of the resist upper layer film to the resist lower layer film by dry etching. Therefore, a highly accurate pattern can be formed by etching the substrate using the resist underlayer film to which the pattern is transferred in this way as a mask and forming the pattern on the substrate.

Furthermore, the present invention is a method for forming a pattern on a substrate by lithography, wherein a resist underlayer film is formed on the substrate using at least the resist underlayer film material of the present invention, and silicon atoms are formed on the underlayer film. A resist intermediate layer film containing a photoresist composition, forming a resist upper layer film of a photoresist composition on the intermediate layer film to form a three-layer resist film, and exposing a pattern circuit region of the resist three-layer film Thereafter, development is performed with a developer to form a resist pattern on the resist upper layer film, and the resist intermediate layer film is etched using the resist upper layer film on which the pattern is formed as a mask, so that at least the resist intermediate layer film on which the pattern is formed is formed. Etch the resist underlayer using the mask, and further etch the substrate using at least the patterned resist underlayer as a mask. That provides a pattern forming method comprising forming a pattern in a plate.

  As described above, the resist underlayer film formed using the resist underlayer film material of the present invention exhibits an excellent antireflection effect when combined with the resist intermediate layer film, and can be particularly excellent in etching resistance during substrate etching. . Therefore, if used as a resist underlayer film in a three-layer resist process, a pattern can be formed on the substrate with higher accuracy.

In this case, as the resist upper layer film, using containing no silicon atom, the etching of the lower layer film the resist intermediate film as a mask, Ru can be performed oxygen gas in the dry etching mainly.

  A resist upper layer film that does not contain a silicon atom has an advantage that it has excellent resolution as compared with a film that contains a silicon atom. Therefore, a pattern transferred to the resist intermediate layer film, and a pattern transferred to the lower layer film by dry etching mainly using oxygen gas using the resist intermediate layer film as a mask can be made highly accurate. Therefore, if the substrate is etched using the resist underlayer film to which the pattern is transferred in this way as a mask and the pattern is formed on the substrate, a pattern with higher accuracy can be formed.

As described above, according to the present invention, particularly for exposure at a short wavelength, an excellent antireflection effect is exhibited by using alone or in combination with a resist intermediate film having an antireflection effect. In addition, the etching rate by CF ₄ / CHF ₃ gas and Cl ₂ / BCl ₃ gas etching used for substrate processing is slower than that of polyhydroxystyrene, cresol novolac, etc., that is, during substrate etching The resist underlayer film material suitable for use in a multilayer resist process, for example, a two-layer or three-layer resist process can be obtained.

Hereinafter, although embodiment of this invention is described, this invention is not limited to these.
As a result of intensive studies to solve the above problems, the present inventors pendant a novolak resin with a cyclic alkyl group having 4 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, and the like. The n-value and k-value ranges can be adjusted, and the etching resistance at the time of substrate etching can be excellent, and the novolak resin in which such a substituent is pendant is used for a two-layer or three-layer resist process or the like. The present invention has been completed by finding a promising material as a resist underlayer film for a multilayer resist process.

（ここで上記一般式（１）中、Ｒ^１は炭素数１〜４の直鎖状、分岐状のアルキレン基であり、Ｒ^２は炭素数４〜２０の環状のアルキル基又は炭素数６〜３０のアリール基であり、ヒドロキシ基、エーテル基、チオエーテル基、エステル基のいずれか１以上の基を含んでいてもよい。） That is, the resist underlayer film material of the present invention is a resist underlayer film material of a multilayer resist film used in lithography, and contains at least a novolac resin. The novolak resin is represented by the following general formula (1). Having a repeating unit substituted with a group.

(Here, in the general formula (1), R ¹ is a linear or branched alkylene group having 1 to 4 carbon atoms, and R ² is a cyclic alkyl group having 4 to 20 carbon atoms or 6 to 6 carbon atoms. 30 aryl groups, which may contain one or more of a hydroxy group, an ether group, a thioether group, and an ester group.)

Such a resist underlayer film material exhibits an excellent antireflection effect when used alone or in combination with a resist intermediate layer film having an antireflection effect, particularly for exposure at a short wavelength, that is, an optimal n value, k It has a value and is excellent in etching resistance during substrate etching.
Moreover, if such a resist underlayer film material is used, the resist pattern shape after development will be good.

In order to use the resist underlayer film as a thin film, not only a high k value but also a higher etching resistance is required during substrate etching. Therefore, etching is carried out by penetrating a normal cresol novolak with an aromatic group, an alicyclic group, etc., particularly a condensed polycyclic hydrocarbon group that improves etching resistance as a substituent represented by the general formula (1). Resistance can be increased. This condensed polycyclic hydrocarbon group also has an effect of increasing the k value at a wavelength of 248 nm and a wavelength of 157 nm.
Such a resist underlayer film material of the present invention is applicable to both a two-layer resist process and a three-layer resist process.

  For a two-layer resist process or a three-layer resist process for KrF, it is preferable to pendant mainly an anthracene methyl group as a substituent represented by the general formula (1). For a two-layer resist process, it can have an optimum k value (0.15 to 0.3) for obtaining a minimum substrate reflectance of 1% or less, and for a three-layer resist process, two layers The same k value as in the resist process may be used, but in order to further increase the k value, the amount of anthracene methyl group is increased to increase the etching resistance and k value at the time of substrate etching. It can be suppressed to 1% or less.

  In order to use it for a two-layer resist process for ArF, the k value of cresol novolak at a wavelength of 193 nm is as high as about 0.6, and therefore the k value needs to be lowered. In order to lower the k value without lowering the etching resistance during substrate etching, a cresol novolak resin such as an adamantanemethyl group or a naphthalenemethyl group may be pendant with a highly transparent and high etching resistance group at a wavelength of 193 nm. However, if that alone does not reach the optimum k value and the substrate reflectivity cannot be suppressed to 1% or less, it may be co-condensed with naphthol, dicyclopentadiene or the like to further reduce the k value. . Unlike the two-layer resist process for the ArF three-layer resist process, the k value may remain high, and it is not particularly necessary to pendant a highly transparent group at a wavelength of 193 nm, so the etching resistance during substrate etching is high. Preference is given to pendant polycyclic aromatic groups.

For the F ₂ double-layer resist process, since the k value of ordinary novolak resin is low as in the case of KrF, condensed polycyclic aromatic groups having high absorption at a wavelength of 157 nm such as anthracene methyl group and pyrene methyl group are used. It is possible to use different resist underlayer films for the two-layer resist process and the three-layer resist process by adjusting the k value by adjusting the ratio.

Here, specific examples of the substituent —R ¹ —R ² represented by the general formula (1) can be listed below.

As the substituent represented by the general formula (1), a polycyclic aromatic group such as an anthracene methyl group or a pyrene methyl group is most preferably used for exposure at a wavelength of 248 nm.
In order to improve transparency at a wavelength of 193 nm, those having an alicyclic structure and those having a naphthalene structure are preferably used.
On the other hand, at a wavelength of 157 nm, the absorption of the benzene ring is too small to be practical as an antireflection film, and the transparency needs to be lowered. That is, since the benzene ring has a window in which the transparency is improved in the vicinity of the wavelength of 157 nm, there is not sufficient absorption to obtain the antireflection effect, and 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 absorption increases when the absorption wavelength is increased, and these aromatic rings also have an effect of improving etching resistance.

Examples of the method for introducing the substituent of the general formula (1) include a method in which an alcohol represented by the following general formula (3) is introduced into the polymer after polymerization in the ortho position or para position of the hydroxy group of the phenol in the presence of an acid catalyst. It is done. Moreover, it can also superpose | polymerize using the monomer before superposition | polymerization, for example, the phenol compound by which the group shown by General formula (1) obtained by making the alcohol shown by following General formula (3) react with phenol. .
HO-R ¹ -R ² (3)

（ここで上記一般式（２）中、Ｒ^１、Ｒ^２は前述の通りである。Ｒ^３、Ｒ^４、Ｒ^５はヒドロキシ基、炭素数１〜１０の直鎖状、分岐状、環状のアルコキシ基、グリシジルエーテル基、水素原子、炭素数１〜１０のアルキル基、炭素数６〜２０のアリール基、炭素数１〜１０のヒドロキシ基含有のアルキル基、炭素数１〜１０のアシル基のいずれかであり、Ｒ^３、Ｒ^４、Ｒ^５の内少なくとも一つがヒドロキシ基、炭素数１〜１０の直鎖状、分岐状、環状のアルコキシ基、グリシジルエーテル基のいずれかである。Ｒ^６は水素原子、炭素数１〜６の直鎖状、分岐状、環状のアルキル基、炭素数２〜６の直鎖状、分岐状、環状のアルケニル基、炭素数６〜１０のアリール基のいずれかである。） Examples of the resist underlayer film material of the present invention include those in which a novolak resin has a repeating unit represented by the following general formula (2).

(In the general formula (2), R ¹ and R ² are as described above. R ³ , R ⁴ , and R ⁵ are hydroxy groups, linear, branched, and cyclic having 1 to 10 carbon atoms. An alkoxy group, a glycidyl ether group, a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkyl group containing a hydroxy group having 1 to 10 carbon atoms, and an acyl group having 1 to 10 carbon atoms. are ^either, R ^3, R 4, at least one hydroxy group of ^{R 5,} a straight, branched, cyclic alkoxy group, or a glycidyl ether group .R ⁶ Is any of a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, a linear, branched or cyclic alkenyl group having 2 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms. )

  Here, the phenols for obtaining the repeating unit listed in the general formula (2) 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, Resorcinol, 2-methylresorcinol, 4- Tilresorcinol, 5-methylresorcinol, catechol, 4-t-butylcatechol, 2-methoxyphenol, 3-methoxyphenol, 2-propylphenol, 3-propylphenol, 4-propylphenol, 2-isopropylphenol, 3-isopropyl Examples thereof include phenol, 4-isopropylphenol, 2-methoxy-5-methylphenol, 2-t-butyl-5-methylphenol, pyrogallol, thymol, and isothymol.

  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.

  In order to convert the phenols into novolak resins, a condensation reaction with aldehydes is used. 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 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, and acetic acid. The usage-amount of these acidic catalysts is 1 * 10 < ^-5 > ^-5 * 10 < ^-1 > mol with respect to 1 mol of phenols, for example.

  As a reaction solvent in polycondensation, water, methanol, ethanol, propanol, butanol, tetrahydrofuran, dioxane, a mixed solvent thereof or the like can be used. These solvents are, for example, in the range of 0 to 2,000 parts by mass with respect to 100 parts by mass of the reaction raw material.

  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. There are a method in which phenols, aldehydes, and a catalyst are charged all at once, and a method in which phenols and aldehydes are dropped in the presence of the 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 molecular weight in terms of polystyrene of the novolak resin preferably has a weight average molecular weight (Mw) of 2,000 to 30,000, particularly 3,000 to 20,000. The molecular weight distribution is preferably in the range of 1.2 to 7, but the crosslinking efficiency is higher when the monomer component, oligomer component or low molecular weight body having a molecular weight (Mw) of 1000 or less is cut to narrow the molecular weight distribution. Moreover, contamination around the baking cup can be prevented by suppressing the volatile components in the baking.

  The resist underlayer film material of the present invention is based on, for example, a polymer of cresol novolac having a repeating unit represented by the general formula (2), but other polymers can also be blended.

  For example, hydrogenation can be performed in order to improve the transparency at a wavelength of 193 nm of the resin having a repeating unit represented by the general formula (2) of the present invention. A preferable hydrogenation ratio is 80 mol% or less of an aromatic group such as phenol.

  The base resin for resist underlayer film material of the present invention is characterized by containing the substituent-containing cresol novolak resin represented by the general formula (1), and blended with conventional polymers mentioned as antireflection film materials You can also

  The glass transition point of a cresol novolak resin having a molecular weight (Mw) of 5000 is 150 ° C. or higher, and this alone may have poor deep hole filling characteristics such as via holes. In order to embed holes without generating voids, a technique is employed in which a polymer having a low glass transition point is used and a resin is embedded to the bottom of the hole while heat-flowing at a temperature lower than the crosslinking temperature (for example, JP 2000-294504 gazette.) Therefore, a polymer having a low glass transition point, particularly a polymer having a glass transition point of 180 ° C. or lower, particularly 100 to 170 ° C., such as acrylic derivatives, vinyl alcohol, vinyl ethers, allyl ethers, styrene derivatives, allylbenzene derivatives, ethylene, By blending with olefins such as propylene and butadiene, and polymers by metathesis ring-opening polymerization, the glass transition point can be lowered, and the via hole filling characteristics can be improved.

  Moreover, in this invention, since the substituent shown by General formula (1) is pendant, there exists a merit that a glass transition point falls rather than a normal novolak resin. Although depending on the type of pendant substituent or the proportion thereof, the glass transition point of 10 to 50 ° C. can be lowered.

As another method for lowering the glass transition point, a hydrogen atom of a hydroxy group of cresol novolak is a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a t-butyl group, or a t-amyl group. And an acid labile group such as acetal, an acetyl group, a pivaloyl group, and the like.
The substitution rate at this time is in the range of 10 to 60 mol%, preferably 15 to 50 mol% of the hydroxyl group of cresol novolak.

In addition to the resist underlayer film material as described above, by further adding a crosslinking agent, an acid generator, an organic solvent, etc., the coating property of the material on a substrate or the like is improved, or by baking after coating, The cross-linking reaction in the resist underlayer film can be promoted. Therefore, such a resist underlayer film has good film thickness uniformity, is less likely to be intermixed with the resist upper layer film, and has low diffusion of low molecules into the resist upper layer film.
These will be described in detail below.

  One of the performance required for the resist underlayer film is that there is no intermixing with the resist upper layer film or resist intermediate layer film, and that there is no diffusion of low molecular components into the resist upper layer film (for example, Proc SPIE Vol. 2195, p225-229 (1994)). In order to prevent these problems, a method is generally employed in which a resist underlayer film is formed on a substrate by spin coating or the like and then thermally crosslinked by baking. Therefore, in the present invention, when a crosslinking agent is added as a component of the resist underlayer film material, a crosslinkable substituent may be introduced into the polymer.

  Specific examples of the crosslinking agent that can be used in the present invention include a melamine compound, a guanamine compound, a glycoluril compound, or a urea compound substituted with at least one group selected from a methylol group, an alkoxymethyl group, and an acyloxymethyl group. Examples 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 can also be used as a crosslinking agent.

  Among specific examples of the crosslinking agent, when an epoxy compound is exemplified, tris (2,3-epoxypropyl) isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, triethylolethane triglycidyl ether and the like can be mentioned. It is done. Specific examples of the melamine compound include hexamethylol melamine, hexamethoxymethyl melamine, a compound in which 1 to 6 methylol groups of hexamethylol melamine are methoxymethylated, and a mixture thereof, hexamethoxyethyl melamine, hexaacyloxymethyl melamine, Examples include compounds in which 1 to 6 methylol groups of hexamethylolmelamine are acyloxymethylated, and mixtures thereof. Examples of the guanamine compound include tetramethylolguanamine, tetramethoxymethylguanamine, a compound in which 1 to 4 methylol groups of tetramethylolguanamine are methoxymethylated, and a mixture thereof, tetramethoxyethylguanamine, tetraacyloxyguanamine, and tetramethylolguanamine. Examples include compounds in which 4 methylol groups are acyloxymethylated, and mixtures thereof. Examples of the glycoluril compound include tetramethylol glycoluril, tetramethoxyglycoluril, tetramethoxymethylglycoluril, a compound in which 1 to 4 of the methylol groups of tetramethylolglycoluril are methoxymethylated, a mixture thereof, and tetramethylolglycoluril. Examples thereof include compounds in which 1 to 4 methylol groups are acyloxymethylated, and mixtures thereof. Examples of the urea compound include tetramethylol urea, tetramethoxymethyl urea, compounds in which 1 to 4 methylol groups of tetramethylol urea are methoxymethylated, a mixture thereof, and tetramethoxyethyl urea.

  Examples of the isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate. Examples of the azide compound include 1,1′-biphenyl-4,4′-bisazide and 4,4′-methylidenebis. Examples include azide and 4,4′-oxybisazide.

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

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

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

  In the resist underlayer film material of the present invention, an acid generator for further promoting the crosslinking reaction by heat or the like can be added. There are acid generators that generate an acid by thermal decomposition and those that generate an acid by light irradiation, and any of them can be added.

As an acid generator used in the resist underlayer film material of the present invention,
i. An onium salt of the following general formula (P1a-1), (P1a-2), (P1a-3) or (P1b),
ii. A diazomethane derivative of the following general formula (P2):
iii. 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.

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

(In the formula, R ^101a , R ^101b and R ^101c are each a linear, branched or cyclic alkyl group, alkenyl group, oxoalkyl group, oxoalkenyl group having 6 to 20 carbon atoms, or 6 to 20 carbon atoms. An aryl group, an aralkyl group having 7 to 12 carbon atoms, or an aryloxoalkyl group, and a part or all of hydrogen atoms of these groups may be substituted by an alkoxy group, etc. R ^101b and R ^101c and may form a ring, when they form a ring, R ^101b, .K indicating each is R ^101c alkylene group having 1 to 6 carbon atoms ^- .R ^101d is representative of a non-nucleophilic counter ion R ^101e , R ^101f and R ^101g are represented by adding a hydrogen atom to R ^101a , R ^101b and R ^101c , R ^101d and R ^101e , and R ^101d , R ^101e and R ^101f form a ring, respectively. In the case of forming a ring, R ^101d and R ^101e and R ^101d And R ^101e and R ^101f represent an alkylene group having 3 to 10 carbon atoms or a heteroaromatic ring having a nitrogen atom in the 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 oxoalkenyl group include 2-oxo-4-cyclohexenyl group and 2-oxo-4-propenyl group. Examples of the aryl group include a phenyl group, a naphthyl group, a p-methoxyphenyl group, an m-methoxyphenyl group, an o-methoxyphenyl group, an ethoxyphenyl group, a p-tert-butoxyphenyl group, and an m-tert-butoxyphenyl group. Alkylphenyl groups such as alkoxyphenyl groups, 2-methylphenyl groups, 3-methylphenyl groups, 4-methylphenyl groups, ethylphenyl groups, 4-tert-butylphenyl groups, 4-butylphenyl groups, dimethylphenyl groups, etc. Alkyl naphthyl groups such as methyl naphthyl group and ethyl naphthyl group, alkoxy naphthyl groups such as methoxy naphthyl group and ethoxy naphthyl group, dialkyl naphthyl groups such as dimethyl naphthyl group and diethyl naphthyl group, dimethoxy naphthyl group and diethoxy naphthyl group Dialkoxynaphthyl group And the like. Examples of the aralkyl group include a benzyl group, a phenylethyl group, and a phenethyl group. As the aryloxoalkyl group, 2-aryl-2-oxoethyl group such as 2-phenyl-2-oxoethyl group, 2- (1-naphthyl) -2-oxoethyl group, 2- (2-naphthyl) -2-oxoethyl group and the like Groups and the like. Non-nucleophilic counter ions of K ⁻ include halide ions such as chloride ion and bromide ion, fluoroalkyl sulfonates such as triflate, 1,1,1-trifluoroethane sulfonate, and nonafluorobutane sulfonate, tosylate, and benzene sulfonate. And aryl sulfonates such as 4-fluorobenzene sulfonate and 1,2,3,4,5-pentafluorobenzene sulfonate, and alkyl sulfonates such as mesylate and butane sulfonate.
The heteroaromatic ring in which R ^101d , R ^101e , R ^101f and R ^101g have a nitrogen atom in the formula is an imidazole derivative (for example, imidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole). Etc.), pyrazole derivatives, furazane derivatives, pyrroline derivatives (eg pyrroline, 2-methyl-1-pyrroline etc.), pyrrolidine derivatives (eg pyrrolidine, N-methylpyrrolidine, pyrrolidinone, N-methylpyrrolidone etc.), imidazoline derivatives, imidazolidine Derivatives, pyridine derivatives (eg pyridine, methylpyridine, ethylpyridine, propylpyridine, butylpyridine, 4- (1-butylpentyl) pyridine, dimethylpyridine, trimethylpyridine, triethylpyridine, phenylpyridine, 3-methyl-2-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-quinolinecarbonitrile, etc.), isoquinoline derivatives, cinnoline derivatives, quinazoline derivatives, quinoxaline derivatives, phthalazine Examples include 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. The

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

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

(Wherein 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).

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

(Wherein 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 numbers 7 to 12 aralkyl groups are shown.)

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

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

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

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

（式中、Ｒ^101a、Ｒ^101bは前記と同様である。）

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

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

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

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

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

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

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

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

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

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

  Examples of the nitrobenzyl sulfonate derivative include nitrobenzyl sulfonate derivatives such as 2,6-dinitrobenzyl p-toluenesulfonate and 2,4-dinitrobenzyl p-toluenesulfonate.

  Examples of sulfonic acid ester derivatives include 1,2,3-tris (methanesulfonyloxy) benzene, 1,2,3-tris (trifluoromethanesulfonyloxy) benzene, 1,2,3-tris (p-toluenesulfonyloxy). Mention may be made of sulfonic acid ester derivatives such as benzene.

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

In particular, triphenylsulfonium trifluoromethanesulfonate, trifluoromethanesulfonate (p-tert-butoxyphenyl) diphenylsulfonium, tris (p-tert-butoxyphenyl) sulfonium trifluoromethanesulfonate, triphenylsulfonium p-toluenesulfonate, p -Toluenesulfonic acid (p-tert-butoxyphenyl) diphenylsulfonium, p-toluenesulfonic acid tris (p-tert-butoxyphenyl) sulfonium, trifluoromethanesulfonic acid trinaphthylsulfonium, trifluoromethanesulfonic acid cyclohexylmethyl (2-oxocyclohexyl) ) Sulfonium, (2-norbornyl) methyl (2-oxocyclohexyl) sulfonyl trifluoromethanesulfonate , 1,2'-naphthyl carbonyl methyl tetrahydrothiophenium triflate onium salts such as,
Bis (benzenesulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (n-butylsulfonyl) diazomethane, bis (isobutylsulfonyl) diazomethane, bis (sec-butylsulfonyl) diazomethane, bis ( diazomethane derivatives such as n-propylsulfonyl) diazomethane, bis (isopropylsulfonyl) diazomethane, bis (tert-butylsulfonyl) diazomethane,
Glyoxime derivatives such as bis-O- (p-toluenesulfonyl) -α-dimethylglyoxime, bis-O- (n-butanesulfonyl) -α-dimethylglyoxime,
Bissulfone derivatives such as bisnaphthylsulfonylmethane,
N-hydroxysuccinimide methanesulfonic acid ester, N-hydroxysuccinimide trifluoromethanesulfonic acid ester, N-hydroxysuccinimide 1-propanesulfonic acid ester, N-hydroxysuccinimide 2-propanesulfonic acid ester, N-hydroxysuccinimide 1-pentanesulfonic acid Preferred examples include sulfonate derivatives of N-hydroxyimide compounds such as esters, N-hydroxysuccinimide p-toluenesulfonate, N-hydroxynaphthalimide methanesulfonate, and N-hydroxynaphthalimide benzenesulfonate.

  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 transfer of acid to the resist upper layer film or resist intermediate layer film. .

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

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

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

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

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

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

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

  Examples of imide derivatives include phthalimide, succinimide, maleimide and the like.

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

  As the organic solvent that can be used in the resist underlayer film material of the present invention, a novolak resin having a repeating unit substituted with a group represented by the general formula (1), an acid generator, a crosslinking agent, and other additives are dissolved. There is no particular limitation as long as it does. 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. It is not limited to.

  Among these organic solvents, diethylene glycol dimethyl ether, 1-ethoxy-2-propanol, ethyl lactate, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and mixed solvents thereof are preferably used in the resist underlayer film material of the present invention.

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

  The present invention is also a method for forming a pattern on a substrate by lithography, wherein at least a resist underlayer film material of the present invention is used to form a resist underlayer film on the substrate, and a photoresist composition is formed on the underlayer film. The resist upper layer film is formed to form a two-layer resist film, the pattern circuit region of the two-layer resist film is exposed, and then developed with a developer to form a resist pattern on the resist upper layer film. Etching the resist underlayer film using the formed resist upper layer mask as a mask, and further etching the substrate using at least the resist underlayer film on which the pattern is formed as a mask to form a pattern on the substrate. Provide a method.

Such a two-layer resist process will be described with reference to FIG.
The resist underlayer film 12 of the present invention can be formed on the substrate 11 by a spin coat method or the like, similarly to the photoresist. After the resist underlayer film 12 is formed by a spin coating method or the like, it is desirable to evaporate the organic solvent and perform baking to promote the crosslinking reaction in order to prevent mixing with the resist upper layer film 13. The baking temperature is preferably in the range of 80 to 300 ° C. and in the range of 10 to 300 seconds. Although the thickness of the resist underlayer film 12 is appropriately selected, it is preferably 30 to 20,000 nm, particularly 50 to 15,000 nm. After forming the resist lower layer film 12, a silicon-containing resist layer (resist upper layer film 13) is formed thereon (see FIG. 6A).

In this case, a known composition can be used as the photoresist composition for forming the resist upper layer film 13.
As a silicon-containing resist for a two-layer resist process, from the point of resistance to oxygen gas etching, a silicon atom-containing polymer such as a polysilsesquioxane derivative or a vinylsilane derivative is used as a base polymer, and an organic solvent, an acid generator, If necessary, a positive-type 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.

When forming the resist upper layer film 13 with the said photoresist composition, a spin coat method is used preferably similarly to the case where the said resist lower layer film 12 is formed. Pre-baking is performed after the resist upper layer film 13 is formed by spin coating or the like, but it is preferably performed at 80 to 180 ° C. for 10 to 300 seconds. Thereafter, the pattern circuit region 15 of the two-layer resist film is exposed according to a conventional method (see FIG. 6B), post-exposure baking (PEB), and developed to obtain a resist pattern (FIG. 6C). )reference).
The thickness of the resist upper layer film 13 is not particularly limited, but is preferably 30 to 500 nm, particularly 50 to 400 nm.
For the development, a paddle method using an alkaline aqueous solution, a dip method, or the like is used, and in particular, a paddle method using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide is preferably used. Then, the substrate is rinsed with pure water and dried by spin drying or nitrogen blowing.

Next, etching is performed using the obtained resist pattern as a mask.
Etching of the resist underlayer film 12 in the two-layer resist process is performed by dry etching mainly using oxygen gas (see FIG. 6D). In the case of dry etching mainly using oxygen gas, in addition to oxygen gas, it is also possible to add inert gas such as He and Ar, and CO, CO ₂ , NH ₃ , SO ₂ , N ₂ and NO ₂ gas. is there. In particular, the latter gas is used for side wall protection for preventing undercut of the pattern side wall.

Etching of the next substrate 11 can also be performed by a conventional method. For example, if the substrate is SiO ₂ or SiN, etching mainly using a chlorofluorocarbon gas, polysilicon (p-Si), Al, or W is chlorine, Etching mainly using a bromine-based gas is performed (FIG. 6E).
When the substrate processing is etched with chlorofluorocarbon gas, the silicon-containing resist in the two-layer resist process is peeled off simultaneously with the substrate processing.
When the substrate is etched with a chlorine-based or bromine-based gas, the silicon-containing resist needs to be removed by dry etching using a chlorofluorocarbon-based gas after the substrate is processed.
The resist underlayer film of the present invention is characterized by excellent etching resistance when etching these substrates.

As shown in FIG. 6, the substrate 11 may be composed of a layer to be processed 11b and a base layer 11a. The base layer 11a of the substrate 11 is not particularly limited, and Si, amorphous silicon (α-Si), p-Si, SiO ₂ , SiN, SiON, W, TiN, Al, etc. Different materials may be used. The layer to be processed _{11b, Si, SiO 2, SiON} , SiN, p-Si, α-Si, W, W-Si, Al, Cu, Al-Si , etc. and various low dielectric films and etching stopper film It is usually used and can be formed to a thickness of 50 to 10,000 nm, particularly 100 to 5,000 nm.

  Furthermore, the present invention is a method for forming a pattern on a substrate by lithography, wherein at least a resist underlayer film material of the present invention is used to form a resist underlayer film on the substrate, and silicon atoms are formed on the underlayer film. After forming a resist intermediate layer film, forming a resist upper layer film of a photoresist composition on the intermediate layer film to form a three-layer resist film, and exposing a pattern circuit region of the resist three-layer film Develop with a developer to form a resist pattern on the resist upper layer film, etch the resist intermediate layer film using the resist upper layer film on which the pattern is formed as a mask, and mask at least the resist intermediate layer film on which the pattern is formed The resist underlayer film is etched, and the substrate is etched using at least the resist underlayer film having the pattern as a mask. A pattern forming method and forming a pattern.

Such a three-layer resist process will be described with reference to FIG.
First, a resist underlayer film 22 is formed on a substrate by a method similar to the above-described two-layer resist process.
Next, in the case of a three-layer resist process, a silicon-containing resist intermediate layer film 24 is formed thereon, and a single-layer resist layer (resist upper layer film 23) not containing silicon is formed thereon (see FIG. 7A). ).

In this case, a well-known thing can be used as a photoresist composition for forming this resist upper layer film.
As the silicon-containing resist intermediate layer film 24 for the three-layer resist process, those based on silsesquioxane are preferably used. By providing the resist intermediate layer film 24 with an effect as an antireflection film, it is possible to suppress substrate reflection. In particular, for exposure at a wavelength of 193 nm, if a material containing a large amount of aromatic groups and having high etching resistance during substrate etching is used as the resist underlayer film, the k value increases and the substrate reflectivity increases. By suppressing this, the substrate reflectance can be reduced to, for example, 0.5% or less. The resist intermediate layer film having an antireflection effect includes an anthracene for exposure at a wavelength of 248 nm and a wavelength of 157 nm, and a silsesquioxane that has a phenyl group or a silicon-silicon bond for exposure at a wavelength of 193 nm and is crosslinked by acid or heat. Is preferably used.
The resist upper layer film 23 in the three-layer resist process may be either a positive type or a negative type, and the same one as a commonly used single layer resist can be used.

When the resist intermediate layer film 24 and the resist upper layer film 23 are formed, a spin coating method is preferably used as in the case of forming the resist lower layer film. In addition, a resist intermediate film formed by a chemical vapor deposition (CVD) method can be used. A SiON film or the like is known as a resist intermediate film having an effect as an antireflection film. Note that the formation of a resist intermediate layer film by spin coating has a cost advantage over CVD.
Thereafter, the pattern circuit region 25 of the three-layer resist film is exposed (see FIG. 7 (b)), post-exposure baking (PEB), and development is performed in accordance with a conventional method to obtain a resist pattern on the resist upper layer film (FIG. 7 (c)).

Next, etching is performed using the obtained resist pattern as a mask.
Etching of the resist intermediate layer film 24 in the three-layer resist process is performed using a fluorocarbon gas or the like, and the resist intermediate layer film 24 is processed using the resist pattern as a mask (see FIG. 7D). Next, dry etching mainly including oxygen gas is performed as in the two-layer resist process, and the resist underlayer film 22 is processed using the pattern transferred to the resist intermediate layer film 24 as a mask (see FIG. 7E). ).

Etching of the next substrate 21 can also be performed by a conventional method. For example, if the substrate is SiO ₂ or SiN, etching mainly using a chlorofluorocarbon gas, polysilicon (p-Si), Al, and W are chlorine-based, Etching mainly using a bromine-based gas is performed (see FIG. 7F).
When the substrate processing is etched with chlorofluorocarbon gas, the silicon-containing resist intermediate layer film 24 of the three-layer resist process is peeled off simultaneously with the substrate processing.
When the substrate is etched with a chlorine-based or bromine-based gas, the silicon-containing resist intermediate film 24 needs to be separated by dry etching with a chlorofluorocarbon-based gas after the substrate is processed.
The resist underlayer film of the present invention is characterized by excellent etching resistance when etching these substrates.

  As shown in FIG. 7, the substrate 21 may be composed of a layer to be processed 21b and a base layer 21a. The processed layer 21b and the base layer 21a of the substrate 21 may be the same as those described in the two-layer resist process.

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.
(Synthesis Example 1)
120 g of m-cresol, 54 g of 37% formalin aqueous solution and 3 g of oxalic acid were added to a 300 mL flask, and the mixture was stirred at 100 ° C. for 24 hours while stirring. After the reaction, it was dissolved in 300 mL of methyl isobutyl ketone, and the catalyst and metal impurities were removed by washing with sufficient water. The solvent was removed under reduced pressure, and the pressure was reduced to 150 ° C. and 2 mmHg to remove moisture and unreacted monomers.
120 g of novolak resin synthesized in a 300 mL flask and 41 g of 9-anthracenemethanol were dissolved in a THF (tetrahydrofuran) solvent, 0.5 g of tosylic acid was added, and the mixture was stirred at 80 ° C. for 24 hours. The catalyst and metal impurities were removed by washing with water, and THF was removed under reduced pressure to obtain 155 g of the following polymer 1.

Molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the ratio of anthracene methyl group in polymer 1 was determined by ¹ H-NMR analysis as follows.
Polymer 1; m-cresol: p-anthracenemethyl-m-cresol (molar ratio)
= 0.65: 0.35
Molecular weight (Mw) = 6,000
Dispersity (Mw / Mn) = 2.70

(Synthesis Example 2)
To a 300 mL flask, 100 g of m-cresol, 38 g of 1-naphthol, 54 g of 37% formalin aqueous solution and 3 g of oxalic acid were added, and the mixture was stirred at 100 ° C. for 24 hours. After the reaction, it was dissolved in 300 mL of methyl isobutyl ketone, and the catalyst and metal impurities were removed by washing with sufficient water. The solvent was removed under reduced pressure, and the pressure was reduced to 150 ° C. and 2 mmHg to remove moisture and unreacted monomers.
132 g of the novolak resin synthesized in a 300 mL flask and 46 g of 9-anthracenemethanol were dissolved in a THF solvent, 0.5 g of tosylic acid was added, and the mixture was stirred at 80 ° C. for 24 hours. The catalyst and metal impurities were removed by washing with water, and THF was removed under reduced pressure to obtain 166 g of the following polymer 2.

Molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the ratio of anthracene methyl group in polymer 2 was determined by ¹ H-NMR analysis as follows.
Polymer 2; m-cresol: p-anthracenemethyl-m-cresol: 1-naphthol (molar ratio) = 0.50: 0.25: 0.25
Molecular weight (Mw) = 7,500
Dispersity (Mw / Mn) = 3.20

(Synthesis Example 3)
120 g of m-cresol, 54 g of 37% formalin aqueous solution and 3 g of oxalic acid were added to a 300 mL flask, and the mixture was stirred at 100 ° C. for 24 hours while stirring. After the reaction, it was dissolved in 300 mL of methyl isobutyl ketone, and the catalyst and metal impurities were removed by washing with sufficient water. The solvent was removed under reduced pressure, and the pressure was reduced to 150 ° C. and 2 mmHg to remove moisture and unreacted monomers.
120 g of novolak resin synthesized in a 300 mL flask and 52 g of 1-adamantane methanol were dissolved in a THF solvent, 0.5 g of tosylic acid was added, and the mixture was stirred at 80 ° C. for 24 hours. The catalyst and metal impurities were removed by washing with water, and THF was removed under reduced pressure to obtain 161 g of the following polymer 3.

Molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the ratio of adamantanemethyl groups in polymer 3 was determined by ¹ H-NMR analysis as follows.
Polymer 3; m-cresol: p-adamantanemethyl-m-cresol (molar ratio)
= 0.55: 0.45
Molecular weight (Mw) = 6,900
Dispersity (Mw / Mn) = 2.90

(Synthesis Example 4)
120 g of m-cresol, 54 g of 37% formalin aqueous solution and 3 g of oxalic acid were added to a 300 mL flask, and the mixture was stirred at 100 ° C. for 24 hours while stirring. After the reaction, it was dissolved in 300 mL of methyl isobutyl ketone, and the catalyst and metal impurities were removed by washing with sufficient water. The solvent was removed under reduced pressure, and the pressure was reduced to 150 ° C. and 2 mmHg to remove moisture and unreacted monomers.
120 g of novolak resin synthesized in a 300 mL flask and 62 g of 1-pyrenemethanol were dissolved in a THF solvent, 0.5 g of tosylic acid was added, and the mixture was stirred at 80 ° C. for 24 hours. The catalyst and metal impurities were removed by washing with water, and THF was removed under reduced pressure to obtain 155 g of the following polymer 4.

When the obtained polymer was measured by ¹ H-NMR and GPC, the following analysis results were obtained.
Polymer 4; m-cresol: p-pyrenemethyl-m-cresol (molar ratio)
= 0.69: 0.31
Molecular weight (Mw) = 6,900
Dispersity (Mw / Mn) = 2.80

(Synthesis Example 5)
To a 300 mL flask, 170 g of m-phenylphenol, 54 g of 37% formalin aqueous solution, and 3 g of oxalic acid were added and stirred at 100 ° C. for 24 hours while stirring. After the reaction, it was dissolved in 300 mL of methyl isobutyl ketone, and the catalyst and metal impurities were removed by washing with sufficient water. The solvent was removed under reduced pressure, and the pressure was reduced to 150 ° C. and 2 mmHg to remove moisture and unreacted monomers.
186 g of novolak resin and 41 g of 9-anthracenemethanol synthesized in a 300 mL flask were dissolved in THF solvent, 0.5 g of tosylic acid was added, and the mixture was stirred at 80 ° C. for 24 hours. The catalyst and metal impurities were removed by washing with water, and THF was removed under reduced pressure to obtain 211 g of the following polymer 5.

Molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the ratio of anthracene methyl group in polymer 5 was determined by ¹ H-NMR analysis as follows.
Polymer 5; m-phenylphenol: p-anthracenemethyl-m-phenylpheno
(Molar ratio) = 0.72: 0.28
Molecular weight (Mw) = 3,500
Dispersity (Mw / Mn) = 2.20

(Synthesis Example 6)
To a 300 mL flask, 85 g of 4-tritylphenol, 160 g of m-cresol, 54 g of 37% formalin aqueous solution, and 3 g of oxalic acid were added and stirred at 100 ° C. for 24 hours while stirring. After the reaction, it was dissolved in 300 mL of methyl isobutyl ketone, and the catalyst and metal impurities were removed by washing with sufficient water. The solvent was removed under reduced pressure, and the pressure was reduced to 150 ° C. and 2 mmHg to remove moisture and unreacted monomers.
205 g of novolak resin synthesized in a 300 mL flask and 41 g of 9-anthracenemethanol were dissolved in a THF solvent, 0.5 g of tosylic acid was added, and the mixture was stirred at 80 ° C. for 24 hours. The catalyst and metal impurities were removed by washing with water, and THF was removed under reduced pressure to obtain 228 g of the following polymer 6.

Molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the ratio of anthracene methyl group in polymer 6 was determined by ¹ H-NMR analysis as follows.
Polymer 6; 4-tritylphenol: m-cresol: p-anthracenemethyl-m-cresol (molar ratio) = 0.22: 0.58: 0.20
Molecular weight (Mw) = 4,500
Dispersity (Mw / Mn) = 4.60

(Comparative Synthesis Example 1)
To a 500 mL flask, 82 g of 4-hydroxystyrene, 85 g of 2-methacrylic acid-1-anthracenemethyl, and 40 g of toluene as a solvent were added. The reaction vessel was cooled to −70 ° C. in a nitrogen atmosphere, and vacuum degassing and nitrogen flow were repeated three times. After raising the temperature to room temperature, 4.1 g of AIBN (azobisisobutyronitrile) was added as a polymerization initiator, and the temperature was raised to 80 ° C. and reacted for 24 hours. This reaction solution was concentrated to 1/2, precipitated in a mixed solution of 300 mL of methanol and 50 mL of water, and the resulting white solid was filtered and dried under reduced pressure at 60 ° C. to obtain 133 g of a white polymer (Comparative Polymer 1). Obtained.

When the obtained polymer was measured by ¹ H-NMR and GPC, the following analysis results were obtained.
Comparative polymer 1; 4-hydroxystyrene: 2-methacrylic acid-1-anthraceneme
Chill (molar ratio) = 56: 44
Molecular weight (Mw) = 14400
Dispersity (Mw / Mn) = 1.77

(Comparative Synthesis Example 2)
An m-cresol novolac resin was synthesized as Comparative Polymer 2.
Comparative polymer 2; molecular weight (Mw) = 8,800
Dispersity (Mw / Mn) = 4.5

(Comparative Synthesis Example 3)
Polyhydroxystyrene was synthesized as Comparative Polymer 3.
Comparative polymer 3; molecular weight (Mw) = 9,200
Dispersity (Mw / Mn) = 1.05

(Examples and comparative examples)
[Preparation of resist underlayer film material and resist interlayer film material]
The novolak resin shown in Synthesis Examples 1 to 6, the polymer shown in Comparative Synthesis Examples 1 to 3, the polymer for silicon-containing intermediate layer, the acid generator shown in AG1 and 2, and the crosslinking agent shown in CR1. Resist underlayer film material (Example) by dissolving it in an organic solvent containing 0.1% by mass of FC-430 (manufactured by Sumitomo 3M) at a ratio shown in Table 1 and filtering with a 0.1 μm fluororesin filter. 1 to 7, Comparative Examples 1 to 3) and resist intermediate layer material (SOG1, 2) were prepared.

酸発生剤： ＡＧ１，２（下記構造式参照）

架橋剤： ＣＲ１（下記構造式参照）

有機溶剤： ＰＧＭＥＡ（プロピレングリコールモノメチルエーテルアセテート） Each composition in Table 1 is as follows.
Polymers 1-6: From synthesis examples 1-6 Comparative polymers 1-3: From comparative synthesis examples 1-3 Silicon-containing intermediate layer polymer:
KrF silicon-containing intermediate layer polymer 1 (molar ratio (m: n) = 0.3: 0.7, molecular weight (Mw) = 2,500), ArF silicon-containing intermediate layer polymer 1 (molar ratio (o: p: q ) = 0.2: 0.5: 0.3, molecular weight (Mw) = 3,400) (see structural formula below)

Acid generator: AG1,2 (see structural formula below)

Cross-linking agent: CR1 (see structural formula below)

Organic solvent: PGMEA (propylene glycol monomethyl ether acetate)

A solution of the resist underlayer film material (Examples 1 to 7, Comparative Examples 1 to 3) or the resist intermediate layer film material (SOG1, 2) thus prepared was applied onto a silicon substrate and baked at 200 ° C. for 60 seconds. Thus, a resist underlayer film having a thickness of 300 nm or a resist intermediate layer film having a thickness of 100 nm was formed.
After forming the resist underlayer film and the resist intermediate layer film, A. The refractive index (n, k) of the resist underlayer film and the resist intermediate layer film at wavelengths of 248 nm, 193 nm, and 157 nm was determined using a spectroscopic ellipsometer (VASE) having a variable incident angle from Woollam, and the results are shown in Table 1.

  As shown in Table 1, in Examples 1 to 7, since each substituent represented by the general formula (1) is pendant to the novolac resin, the n value and the k value are changed at each wavelength. You can see that

[Preparation of resist upper layer film material]
The following polymers (KrF single-layer resist polymer 1, ArF single-layer resist polymer 1) were prepared as the base resin for the resist upper layer film.

ＫｒＦ単層レジストポリマー１は、上に示される繰り返し単位ｒ，ｓ，ｔからなる重合体である。この重合体のモル比及び分子量（Ｍｗ）を以下に示す。
モル比 ｒ：ｓ：ｔ＝０．７０：０．１０：０．２０
分子量（Ｍｗ）＝９，３００

The KrF single layer resist polymer 1 is a polymer composed of the repeating units r, s, and t shown above. The molar ratio and molecular weight (Mw) of this polymer are shown below.
Molar ratio r: s: t = 0.70: 0.10: 0.20
Molecular weight (Mw) = 9,300

The ArF single layer resist polymer 1 is a polymer composed of the repeating units u, v, and w shown above. The molar ratio and molecular weight (Mw) of this polymer are shown below.
Molar ratio u: v: w = 0.40: 0.30: 0.30
Molecular weight (Mw) = 7,800

  Using the prepared polymers (KrF single layer resist polymer 1, ArF single layer resist polymer 1), acid generator (PAG1), base additive (TMMEA), and organic solvent (PGMEA) in the proportions shown in Table 2, KrF A solution of ArF resist upper layer film material was prepared.

塩基添加剤： ＴＭＭＥＡ（下記構造式参照）

有機溶剤： ＰＧＭＥＡ（プロピレングリコールモノメチルエーテルアセテート） Each composition in Table 2 is as follows.
Acid generator: PAG1 (see structural formula below)

Base additive: TMMEA (see structural formula below)

Organic solvent: PGMEA (propylene glycol monomethyl ether acetate)

[Observation of pattern shape]
(1) Observation of resist pattern shape 1) KrF exposure The solution of the resist underlayer film material prepared above (Examples 1, 2, 4, 5, 6, 7 and Comparative Examples 1 to 3) was changed to SiO ₂ having a film thickness of 300 nm. The resultant was applied onto a substrate having the resist and baked at 220 ° C. for 90 seconds to form a resist underlayer film having a thickness of 300 nm. Next, a solution SOG1 of the resist intermediate layer film material (SOG1) prepared above was applied thereon and baked at 200 ° C. for 60 seconds to form a resist intermediate layer film having a thickness of 130 nm. Next, the KrF resist upper layer material solution prepared above was applied and baked at 120 ° C. for 60 seconds to form a 200 nm thick resist upper layer film.
Next, exposure was performed with a KrF exposure apparatus (Nikon Corp .; S203B, NA 0.68, σ0.75, 2/3 ring illumination, Cr mask), baked at 120 ° C. for 60 seconds (PEB), and 2.38% by mass. Development was performed with an aqueous tetramethylammonium hydroxide (TMAH) solution for 60 seconds to obtain a positive resist pattern of 0.15 μmL / S (line and space). Table 3 shows the results of observation of the obtained resist pattern shape with an electron microscope (S-4700) manufactured by Hitachi, Ltd.

2) ArF exposure The solution of the resist underlayer film material prepared above (Examples 1 to 7, Comparative Examples 1 to 3) was applied onto a substrate having a 300 nm thick SiO ₂ film and baked at 200 ° C. for 60 seconds. Thus, a resist underlayer film having a thickness of 300 nm was formed. Next, a solution of the resist intermediate layer material (SOG2) prepared above was applied thereon and baked at 200 ° C. for 60 seconds to form a resist intermediate layer film having a thickness of 100 nm. Next, the ArF resist upper layer film material solution prepared above was applied and baked at 130 ° C. for 60 seconds to form a 200 nm thick resist upper layer film. Next, exposure was performed with an ArF exposure apparatus (Nikon Corp .; S305B, NA 0.68, σ 0.85, 2/3 ring illumination, Cr mask), baked at 110 ° C. for 60 seconds (PEB), and 2.38% by mass. Development was performed with an aqueous tetramethylammonium hydroxide (TMAH) solution for 60 seconds to obtain a positive pattern of 0.12 μmL / S. Table 4 shows the results of observation of the obtained resist pattern shape with an electron microscope (S-4700) manufactured by Hitachi, Ltd.

(2) Observation of pattern shape transferred to resist intermediate layer film Next, after forming a resist pattern using the same material and method as used in the observation of the resist pattern shape, the obtained resist pattern is resisted. The film was transferred to the intermediate layer film under the following conditions.
Etching conditions 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

  Tables 3 and 4 show the results of observing the obtained pattern shape with an electron microscope (S-4700) manufactured by Hitachi, Ltd.

(3) Observation of pattern shape transferred to resist underlayer film Next, using the same material and method as used in the observation of the pattern shape transferred to the resist intermediate layer film, the resist pattern is formed into a resist intermediate layer. The resulting pattern was transferred to the film and transferred to the resist underlayer film by etching mainly comprising the following oxygen gas.
Etching conditions are as shown below.
Chamber pressure 450mTorr
RF power 600W
Ar gas flow rate 40sccm
O ₂ gas flow rate 60sccm
Gap 9mm
Time 20sec

  Tables 3 and 4 show the results of observing the obtained pattern shape with an electron microscope (S-4700) manufactured by Hitachi, Ltd.

(4) Observation of the pattern shape formed on the substrate Next, the resist underlayer film on which the pattern is formed is masked using the same material and method as used in the observation of the pattern shape transferred to the resist underlayer film. The substrate was etched with CHF ₃ / CF ₄ gas using a dry etching apparatus TE-8500P manufactured by Tokyo Electron Limited.
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

  Tables 3 and 4 show the results of observing the obtained pattern shape with an electron microscope (S-4700) manufactured by Hitachi, Ltd.

  As shown in Tables 3 and 4, in the resist underlayer film materials of Examples 1 to 7, the resist pattern shape after development, the pattern shape transferred to the resist intermediate layer film, and transferred to the resist underlayer film It can be seen that both the pattern shape and the pattern shape transferred to the substrate are good, and a pattern having a high aspect ratio can be formed.

[Dry etching resistance evaluation]
In the dry etching resistance test, a solution of the resist underlayer film material (Examples 1 to 7 and Comparative Examples 1 to 3) prepared as described above was applied on a silicon substrate and baked at 200 ° C. for 60 seconds to obtain a film thickness. A 300 nm resist underlayer film was formed. This was evaluated under the following two conditions.
(1) Etching Test with CHF ₃ / CF ₄ Gas Using a dry etching apparatus TE-8500P manufactured by Tokyo Electron Limited, the difference in film thickness of the resist underlayer film before and after etching was measured.
Etching conditions are the same as those for observing the pattern shape formed on the substrate.
The results are shown in Table 5.

(2) using an etching test Nichiden Anelva Co., Ltd. dry etching apparatus L-507D-L with Cl ₂ / BCl ₃ based gas was determined film thickness difference of the resist underlayer film before and after the etching.
Etching conditions are as shown below.
Chamber pressure 40.0Pa
RF power 300W
Gap 9mm
Cl ₂ gas flow rate 30ml / min
BCl ₃ gas flow rate 30ml / min
CHF ₃ gas flow rate 100ml / min
O ₂ gas flow rate 2ml / min
60 sec
The results are shown in Table 6.

As shown in Tables 5 and 6, in Examples 1 to 7, the etching rate with CHF ₃ / CF ₄ gas and the etching rate with Cl ₂ / BCl ₃ gas were compared with those in Comparative Examples 1 to 3. And slow. Therefore, it can be seen that the resist underlayer films of Examples 1 to 7 are very excellent in etching resistance during substrate etching.

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

The film thickness and substrate of the resist underlayer film when the refractive index k value of the resist underlayer film in the two-layer resist process is fixed at 0.3 and the refractive index n value is changed in the range of 1.0 to 2.0. It is a graph which shows the relationship of a reflectance (exposure wavelength is 193 nm, n value of resist upper layer film is 1.74, and k value is 0.02). Relationship between the film thickness of the resist underlayer film and the substrate reflectance when the refractive index n value of the resist underlayer film in the two-layer resist process is fixed at 1.5 and the k value is changed in the range of 0 to 0.8. (The exposure wavelength is 193 nm, the n value of the resist upper layer film is 1.74, and the k value is 0.02). In the three-layer resist process, the refractive index n value of the resist underlayer film is fixed to 1.5, the k value is fixed to 0.6, the film thickness is fixed to 500 nm, the n value of the resist intermediate film is set to 1.5, and the k value is set to 0. It is a graph which shows the change of a board | substrate reflectance when changing the range of -0.4 and a film thickness in the range of 0-400 nm. In the three-layer resist process, the refractive index n value of the resist lower layer film is fixed to 1.5, the k value is fixed to 0.2, the n value of the resist intermediate layer film is fixed to 1.5, and the k value is fixed to 0.1. 4 is a graph showing a change in substrate reflectivity when the thickness of the resist intermediate layer film is changed. In the three-layer resist process, the refractive index n value of the resist underlayer film is fixed to 1.5, the k value is fixed to 0.6, the n value of the intermediate layer is fixed to 1.5, and the k value is fixed to 0.1. It is a graph which shows the change of a board | substrate reflectance when changing the film thickness of an intermediate | middle layer film. It is explanatory drawing which shows an example of the pattern formation method of this invention by a two-layer resist process. It is explanatory drawing which shows an example of the pattern formation method of this invention by a 3 layer resist process.

Explanation of symbols

11, 21 ... substrate, 11a ... base layer, 11b ... layer to be processed,
12, 22 ... resist underlayer film, 13, 23 ... resist upper layer film,
15, 25 ... Pattern circuit region, 24 ... Resist intermediate layer film.

Claims (7)

A resist underlayer film material of a multilayer resist film used in lithography, at least comprising a novolak resin, the novolak resin is one having a Repetitive return unit that is represented by the following general formula (2) A resist underlayer film material characterized by the above.

(In the above general formula (2), R ¹ is a linear or branched alkylene group having 1 to 4 carbon atoms, and R ² is a cyclic alkyl group having 4 to 20 carbon atoms or 6 to 6 carbon atoms. It is an aryl group of 30 and may contain any one or more of a hydroxy group, an ether group, a thioether group, and an ester group R ³ , R ⁴ , and R ⁵ are a hydroxy group and have 1 to 10 carbon atoms Linear, branched or cyclic alkoxy group, glycidyl ether group, hydrogen atom, alkyl group having 1 to 10 carbon atoms, aryl group having 6 to 20 carbon atoms, alkyl group containing a hydroxy group having 1 to 10 carbon atoms, Any one of acyl groups having 1 to 10 carbon atoms, and at least one of R ³ , R ⁴ and R ⁵ is a hydroxy group, a linear, branched or cyclic alkoxy group having 1 to 10 carbon atoms, glycidyl ether is any of the groups .R ⁶ Any one of a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, a linear, branched or cyclic alkenyl group having 2 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms in is.) The resist underlayer film material according to claim 1, wherein the resist underlayer film material further contains one or more of a crosslinking agent, an acid generator, and an organic solvent. A method of forming a pattern on a substrate by lithography, wherein a resist underlayer film is formed on the substrate using at least the resist underlayer film material according to claim 1, and a photoresist is formed on the underlayer film. A resist upper layer film of the composition is formed to form a two-layer resist film, the pattern circuit region of the two-layer resist film is exposed, and then developed with a developer to form a resist pattern on the resist upper layer film. A resist underlayer film formed by etching the resist underlayer film, and the substrate is etched using at least the resist underlayer film formed with the mask as a mask to form a pattern on the substrate Forming method. Examples resist upper layer film, using those containing silicon atoms in the base resin, the resist etching of the underlying film to mask the upper layer film, according to claim 3, characterized in that in the dry etching using oxygen gas as a main component The pattern forming method according to 1. A method of forming a pattern on a substrate by lithography, wherein a resist underlayer film is formed on the substrate using at least the resist underlayer film material according to claim 1 , and silicon atoms are formed on the underlayer film. A resist intermediate layer film containing a photoresist composition, forming a resist upper layer film of a photoresist composition on the intermediate layer film to form a three-layer resist film, and exposing a pattern circuit region of the resist three-layer film Thereafter, development is performed with a developer to form a resist pattern on the resist upper layer film, and the resist intermediate layer film is etched using the resist upper layer film on which the pattern is formed as a mask, so that at least the resist intermediate layer film on which the pattern is formed is formed. Etch the resist underlayer using the mask, and further etch the substrate using at least the patterned resist underlayer as a mask. Pattern forming method comprising forming a pattern in a plate. Examples resist upper layer film, using containing no silicon atom, wherein the etching of the lower layer film the resist intermediate film as a mask, to claim 5, characterized in that in the dry etching using oxygen gas as a main component Pattern forming method.   -R in the general formula (2) ¹ -R ² 3. The resist underlayer film material according to claim 1, wherein is selected from any of the following substituents.

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