JP4763511B2 - Resist protective film material and pattern forming method - Google Patents

Description

  The present invention is performed by photolithography for fine processing in a manufacturing process of a semiconductor element or the like, for example, using an ArF excimer laser having a wavelength of 193 nm as a light source, and inserting a liquid (for example, water) between a projection lens and a substrate. In immersion photolithography, the present invention relates to a resist protective film material for forming a protective film on a photoresist film in order to protect the photoresist film, and a pattern forming method using the same.

  In recent years, with the higher integration and higher speed of LSIs, there is a demand for finer pattern rules. In light exposure currently used as a general-purpose technology, the intrinsic resolution limit derived from the wavelength of the light source Is approaching.

  As exposure light used for 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 has been widely used. As a means for further miniaturization, a method of shortening the exposure wavelength is effective, and for mass production processes after 64 Mbit (process size is 0.25 μm or less) DRAM (Dynamic Random Access Memory). As a light source for exposure, a short wavelength KrF excimer laser (248 nm) was used in place of i-line (365 nm).

  However, in order to manufacture DRAMs with a density of 256M and 1G or more that require finer processing technology (processing dimensions of 0.2 μm or less), a light source with a shorter wavelength is required, and an ArF excimer has been used for about 10 years. Photography using a laser (193 nm) has been studied in earnest.

Initially, ArF lithography was supposed to be applied from 180 nm node device fabrication, but KrF excimer lithography was extended to 130 nm node device mass production, and full-scale application of ArF lithography is from 90 nm node. Further, a 65 nm node device is being studied in combination with a lens whose NA is increased to 0.9. For the next 45 nm node device, the exposure wavelength has been shortened, and F ₂ lithography with a wavelength of 157 nm was nominated. However, various factors such as an increase in the cost of the scanner by using a large amount of expensive CaF ₂ single crystal for the projection lens, a change in the optical system due to the introduction of a hard pellicle because the durability of the soft pellicle is extremely low, and a reduction in resist etching resistance Because of this problem, it has been proposed to advance F ₂ lithography and early introduction of ArF immersion lithography (see Non-Patent Document 1, for example).

  In ArF immersion lithography, it has been proposed to impregnate water between the projection lens and the substrate. The refractive index of water at 193 nm is 1.44, and it is possible to form a pattern using a lens having an NA of 1.0 or more. Theoretically, the NA can be increased to 1.44. The resolution is improved by the improvement of NA, and the possibility of a 45 nm node is shown by the combination of a lens of NA 1.2 or higher and strong super-resolution technology (for example, see Non-Patent Document 2).

  Here, various problems due to the presence of water on the photoresist film were pointed out. This includes shape change caused by dissolution of the generated acid or amine compound added to the resist film as a quencher in water, pattern collapse due to swelling, and the like. Therefore, it has been proposed that it is effective to provide a protective film between the resist film and water (see, for example, Non-Patent Document 3).

  The protective film formed on the photoresist film has been studied as an antireflection film. For example, there is an ARCOR (antireflective coating on resist) method disclosed in Patent Documents 1 to 3. The ARCOR method is a method including a step of forming a transparent antireflection film on a resist film and peeling off after exposure, and is a method of forming a fine pattern with high accuracy and high alignment accuracy by the simple method. When a perfluoroalkyl compound (perfluoroalkyl polyether, perfluoroalkylamine) of a low refractive index material is used as the antireflection film, the reflected light at the resist-antireflection film interface is greatly reduced, and the dimensional accuracy is improved. As the fluorine-based material, in addition to the above-described materials, for example, perfluoro (2,2-dimethyl-1,3-dioxole) -tetrafluoroethylene copolymer, perfluoro (allyl vinyl ether) shown in Patent Document 4, Amorphous polymers such as cyclized polymers of perfluorobutenyl vinyl ether have been proposed.

  However, since the perfluoroalkyl compound has low compatibility with organic substances, chlorofluorocarbon is used as a diluent for controlling the coating film thickness. Therefore, its use has become a problem. Moreover, the said compound had a problem in uniform film formability, and it could not be said that it was enough as an antireflection film. Further, before developing the photoresist film, the antireflection film had to be peeled off with chlorofluorocarbon. For this reason, there have been significant demerits in practical use, such as the need to add a system for removing the antireflection film to the conventional apparatus and the considerable cost of the fluorocarbon solvent.

  When the antireflection film is peeled off without adding to the conventional apparatus, it is most desirable to peel off using the developing unit. Since the solution used in the developing unit of the photoresist film is an alkaline aqueous solution as a developer and pure water as a rinse solution, it can be said that an antireflection film material that can be easily peeled off with these solutions is desirable. Therefore, many water-soluble antireflection film materials and pattern formation methods using these have been proposed (see, for example, Patent Documents 5 and 6).

  However, since the water-soluble protective film is dissolved in water during exposure, it cannot be used for immersion lithography. On the other hand, water-insoluble fluorine-based polymers have the problems that a special fluorocarbon-based release agent is required and that a special cup for fluorocarbon solvents is required. There was a need for a protective film.

  Here, a developer-soluble top coat based on methacrylate pendant of hexafluoroalcohol has been proposed (for example, see Non-Patent Document 4). This has a high Tg of 150 ° C., high alkali solubility, and good compatibility with a photoresist film.

  On the other hand, when a protective film is formed on the photoresist film, the surface portion of the photoresist film after development may be reduced depending on the type of the photoresist film, and the top shape of the photoresist film may be reduced. There are problems such as rounding. In this case, a good rectangular resist pattern cannot be obtained. For this reason, there has been a demand for a resist protective film material that can more reliably obtain a good rectangular resist pattern.

Proc. SPIE Vol. 4690 xxix Proc. SPIE Vol. 5040 p724 2nd Immersion Work Shop, July 11, 2003, Resist and Cover Material Investing for Immersion Lithography J. et al. Photopolymer Sci. and Technol. Vol. No. 18 5 p615 (2005) JP-A-62-62520 JP-A-62-62521 JP 60-38821 A JP-A-5-74700 JP-A-6-273926 Japanese Patent No. 2803549

  The present invention has been made in view of such problems, and even when a protective film is formed on a photoresist film, a resist protective film material that can more reliably obtain a good rectangular resist pattern, and such An object of the present invention is to provide a pattern forming method using various materials.

（上記式中、Ｒ¹は単結合、又は炭素数１〜１０の直鎖状、分岐状又は環状のアルキレン基である。Ｒ²、Ｒ³は、それぞれ独立に、水素原子、炭素数１〜２０の直鎖状、分岐状又は環状のアルキル基、−ＳＯ_２Ｒ^６のいずれかであり、Ｒ^１とＲ^２、Ｒ^１とＲ³、Ｒ²とＲ³のいずれかが、それぞれ結合して環を形成していても良い。Ｒ^６は、炭素数１〜１０の直鎖状、分岐状又は環状のアルキル基であり、アルキル基の水素原子の全部又は一部がフッ素原子で置換されていても良い。） The present invention has been made to solve the above problems, and is a resist protective film material for forming a protective film on a photoresist film, and at least an amino group represented by the following general formula (1): , that provides a resist protective film material, characterized in that of those containing a polymer compound containing a repeating unit having one or more of the sulfonamide group.

(In the above formula, R ¹ is a single bond or a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms. R ² and R ³ are each independently a hydrogen atom, Any one of 20 linear, branched or cyclic alkyl groups, —SO ₂ R ⁶ , and any one of R ¹ and R ² , R ¹ and R ³ , R ² and R ³ may be bonded to each other; R ⁶ is a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, and all or part of the hydrogen atoms of the alkyl group are substituted with fluorine atoms. May be.)

（上記式中、Ｒ¹〜Ｒ^３は前述の通りである。Ｒ^４、Ｒ^５は、それぞれ独立に、水素原子、フッ素原子、メチル基、トリフルオロメチル基のいずれかである。Ｘは、−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−Ｒ⁷−Ｃ（＝Ｏ）−Ｏ−、−Ｏ−Ｒ⁷−Ｃ（＝Ｏ）−Ｏ−のいずれかである。Ｒ⁷は、炭素数１〜１０の直鎖状、分岐状又は環状のアルキレン基である。ａ，ｂは、０≦ａ≦０．５、０≦ｂ≦０．５、０＜ａ＋ｂ≦０．５の範囲である。） In this case, the repeating unit having at least one of the amino group and the sulfonamide group represented by the general formula (1) in the polymer compound is a repeating unit represented by the following general formula (2). It is not preferred.

(In the above formula, R ^{1 to} R ³ are as described above. R ⁴ and R ⁵ are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. X is —O—, —C (═O) —O—, —C (═O) —O—R ⁷ —C (═O) —O—, —O—R ⁷ —C (═O) —O— R ⁷ is a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms, a and b are 0 ≦ a ≦ 0.5, 0 ≦ b ≦ 0.5, 0 <a + b ≦ 0.5.)

  As described above, when a protective film is formed on the photoresist film, depending on the type of the photoresist film, the surface portion of the developed photoresist film may be reduced, and the photoresist film on which the resist pattern is formed is formed. There is a problem that the shape of the top portion is rounded. This is considered to be because the amine compound added to the photoresist film moves to the protective film thereon. On the other hand, the resist protective film material of the present invention contains a polymer compound containing a repeating unit having at least one of an amino group and a sulfonamide group represented by the general formula (1). For this reason, if a protective film is formed on the photoresist film using this, the migration of the amine compound from the photoresist film can be effectively prevented. For example, the surface portion of the photoresist film after development It is possible to more reliably prevent film loss. For this reason, a favorable rectangular resist pattern can be obtained more reliably.

In the present invention, the resist protective film material, an alkyl group, have the preferred to those containing a polymer compound containing a repeating unit having one or more of the fluoroalkyl group.

（上記式中、Ｒ^８、Ｒ^１０は、それぞれ独立に、水素原子、フッ素原子、メチル基、トリフルオロメチル基のいずれかである。Ｘ^２は、それぞれ独立に、単結合、−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−Ｒ^１６−Ｃ（＝Ｏ）−Ｏ−のいずれかである。Ｒ^１６は、炭素数１〜１０の直鎖状、分岐状又は環状のアルキレン基であり、アルキレン基の水素原子の全部又は一部がフッ素原子で置換されていても良い。Ｒ^９は、それぞれ独立に、炭素数１〜２０の直鎖状、分岐状又は環状のアルキル基であり、アルキル基の水素原子の全部又は一部がフッ素原子で置換されていても良く、エーテル基、エステル基を有していても良い。Ｒ^１１〜Ｒ^１４は、それぞれ独立に、水素原子、フッ素原子、メチル基、トリフルオロメチル基のいずれかであり、Ｒ^１１〜Ｒ^１４の内、いずれかが少なくとも１個以上のフッ素原子を有する。ｍは、１又は２である。（ｃ−１）、（ｃ−２）、（ｃ−３）、（ｃ−４）、（ｃ−５）は、０≦（ｃ−１）≦０．９、０≦（ｃ−２）≦０．９、０≦（ｃ−３）≦０．９、０≦（ｃ−４）≦０．９、０≦（ｃ−５）≦０．９、０≦（ｃ−１）＋（ｃ−２）＋（ｃ−３）＋（ｃ−４）＋（ｃ−５）≦０．９の範囲である。） In this case, the alkyl group of the polymer compound, the repeating units having one or more of the fluoroalkyl group, Ru can be assumed to be the repeating unit represented by the following general formula (3).

(In the above formula, R ⁸ and R ¹⁰ are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. X ² is independently a single bond, —O—, Or —C (═O) —O— or —C (═O) —O—R ¹⁶ —C (═O) —O—, wherein R ¹⁶ is a straight chain having 1 to 10 carbon atoms, It is a branched or cyclic alkylene group, and all or part of the hydrogen atoms of the alkylene group may be substituted with fluorine atoms, and each R ⁹ is independently a linear or branched group having 1 to 20 carbon atoms. Or all or part of the hydrogen atoms of the alkyl group may be substituted with fluorine atoms, or may have an ether group or an ester group, R ^{11 to} R ¹⁴ are Each independently of a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. And in either ^{displacement,} .m of R 11 ^{to R 14,} either with at least one fluorine atom is 1 or 2. (C-1), (c-2), (c- 3), (c-4), and (c-5) are 0 ≦ (c-1) ≦ 0.9, 0 ≦ (c-2) ≦ 0.9, 0 ≦ (c-3) ≦ 0. 9, 0 ≦ (c−4) ≦ 0.9, 0 ≦ (c−5) ≦ 0.9, 0 ≦ (c−1) + (c−2) + (c−3) + (c−4) ) + (C-5) ≦ 0.9.)

  Thus, if the resist protective film material contains a polymer compound containing a repeating unit having one or more of an alkyl group and a fluoroalkyl group, a protective film is formed using this, Water repellency and water slidability can be further improved, and mixing with a photoresist film can be effectively prevented.

Furthermore, in the present invention, the resist protective film material, a carboxyl group, have the preferred to those containing a polymer compound containing a repeating unit having one or more of α-trifluoromethyl alcohol group.

（上記式中、Ｒ^１８、Ｒ^２０は、それぞれ独立に、水素原子、フッ素原子、メチル基、トリフルオロメチル基のいずれかである。Ｙは、それぞれ独立に、単結合、−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−Ｒ^２８−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−Ｒ^２８−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−Ｒ^２８−Ｏ−Ｃ（＝Ｏ）−のいずれかである。Ｒ^２８は、炭素数１〜１０の直鎖状、分岐状又は環状のアルキレン基であり、アルキレン基の水素原子の全部又は一部がフッ素原子で置換されていても良い。Ｒ^２６は、それぞれ独立に、単結合、炭素数１〜１０の直鎖状、分岐状又は環状のアルキレン基又はアルカントリイル基のいずれかであり、アルキレン基又はアルカントリイル基の水素原子の全部又は一部がフッ素原子で置換されていても良く、Ｒ^１７は、それぞれ独立に、水素原子、フッ素原子、メチル基、トリフルオロメチル基、ジフルオロメチル基のいずれかであり、Ｒ^２６とＲ^１７は、結合して環を形成していても良く、環の中にエーテル基、水素原子の全部又は一部がフッ素原子で置換されたアルキレン基、トリフルオロメチル基のうち１つ以上の基を有していても良い。ｎは、それぞれ独立に、１又は２である。（ｄ−１）、（ｄ−２）は、０≦（ｄ−１）≦０．９、０≦（ｄ−２）≦０．９、０≦（ｄ−１）＋（ｄ−２）≦０．９の範囲である。） In this case, the repeating unit having an α-trifluoromethyl alcohol groups of the polymer compound is, Ru can be assumed to be the repeating unit represented by the following general formula (4).

(In the above formula, each of R ¹⁸ and R ²⁰ is independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Y is independently a single bond, —O—, — C (═O) —O—, —C (═O) —O—R ²⁸ —C (═O) —O—, —C (═O) —O—R ²⁸ —O—, —C (═O ) —O—R ²⁸ —O—C (═O) —, wherein R ²⁸ is a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms, and is a hydrogen atom of the alkylene group. R ²⁶ may be each independently a single bond, a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms, or an alkanetriyl group. Any or all of the hydrogen atoms of the alkylene group or alkanetriyl group are substituted with fluorine atoms. May have, R ¹⁷ are each independently a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or a difluoromethyl group, R ²⁶ and R ¹⁷ are linked to form a ring The ring may have one or more groups selected from an ether group, an alkylene group in which all or a part of hydrogen atoms are substituted with fluorine atoms, and a trifluoromethyl group. Each is independently 1 or 2. (d-1) and (d-2) are 0 ≦ (d−1) ≦ 0.9, 0 ≦ (d-2) ≦ 0.9, 0 ≦ ( d-1) + (d-2) ≦ 0.9.

（上記式中、Ｒ^２９は、水素原子、フッ素原子、メチル基、トリフルオロメチル基、−ＣＯＯＨ、−ＣＨ_２−ＣＯＯＨのいずれかである。Ｒ^１９は、水素原子、フッ素原子、メチル基、トリフルオロメチル基、−ＣＯＯＨ、−ＣＨ_２−ＣＯＯＨのいずれかである。Ｙは、それぞれ独立に、単結合、−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−Ｒ^２８−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−Ｒ^２８−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−Ｒ^２８−Ｏ−Ｃ（＝Ｏ）−のいずれかである。Ｒ^２８は、炭素数１〜１０の直鎖状、分岐状又は環状のアルキレン基であり、アルキレン基の水素原子の全部又は一部がフッ素原子で置換されていても良い。Ｒ^２６は、それぞれ独立に、単結合、炭素数１〜１０の直鎖状、分岐状又は環状のアルキレン基又はアルカントリイル基のいずれかであり、アルキレン基又はアルカントリイル基の水素原子の全部又は一部がフッ素原子で置換されていても良い。ｎは、それぞれ独立に、１又は２である。（ｅ−１）、（ｅ−２）は、０≦（ｅ−１）≦０．９、０≦（ｅ−２）≦０．９、０≦（ｅ−１）＋（ｅ−２）≦０．９の範囲である。） In this case, the repeating unit having a carboxyl group of the polymer compound is, Ru can be assumed to be the repeating unit represented by the following general formula (5).

(In the above formula, R ²⁹ is any one of a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, —COOH, —CH ₂ —COOH. R ¹⁹ is a hydrogen atom, a fluorine atom, a methyl group, Any one of a trifluoromethyl group, —COOH, and —CH ₂ —COOH, each of Y is independently a single bond, —O—, —C (═O) —O—, —C (═O) —; O—R ²⁸ —C (═O) —O—, —C (═O) —O—R ²⁸ —O—, —C (═O) —O—R ²⁸ —O—C (═O) — R ²⁸ is a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms, and all or part of the hydrogen atoms of the alkylene group may be substituted with fluorine atoms. R ²⁶ independently represents a single bond, a straight, alkylene branched or cyclic Or an alkanetriyl group, and all or part of the hydrogen atoms of the alkylene group or alkanetriyl group may be substituted with fluorine atoms, and n is independently 1 or 2. (E-1) and (e-2) are 0≤ (e-1) ≤0.9, 0≤ (e-2) ≤0.9, 0≤ (e-1) + (e-2) ≦ 0.9.)

  Thus, if the resist protective film material contains a polymer compound containing a repeating unit having one or more of a carboxyl group and an α-trifluoromethyl alcohol group, a protective film formed using the same It has high alkali solubility and can be more easily peeled off with an alkaline developer during development. This protective film also has good compatibility with the photoresist film.

In the present invention, the resist protective film material further, and even not preferable as it contains the solvent.

  Thus, if the resist protective film material further contains a solvent, the film formability is further improved.

In addition, the present invention includes at least a step of forming a photoresist film on a substrate, a step of forming a resist protective film on the photoresist film using the resist protective film material of the present invention, and exposure. a step, that provide a pattern forming method characterized by comprising the step of developing with a developer.

  Of course, it goes without saying that other various processes such as an etching process, a resist removal process, and a cleaning process may be performed.

Further, in the pattern forming method of the present invention, the exposure step, have preferably carried out by immersion lithography performed by inserting a liquid between the projection lens and the substrate.

  In this way, a finer resist pattern can be formed on the photoresist film by performing the exposure process by immersion lithography.

In the pattern forming method of the present invention, the exposure step can be performed using a light source having an exposure wavelength in the range of 180 to 250 nm and water as a liquid inserted between the projection lens and the substrate. The

  Thus, water can be used as the liquid used in immersion lithography, for example. Then, by inserting water between the projection lens and the substrate and performing exposure using a light source having an exposure wavelength in the range of 180 to 250 nm, a much finer resist pattern can be formed.

In the pattern forming method of the present invention, in the development step, development is performed using an alkaline developer to form a resist pattern on the photoresist film, and at the same time, the resist protective film on the photoresist film is peeled off. It has preferred.

  Thus, in the development process, development is performed using an alkaline developer, and a resist pattern is formed on the photoresist film. At the same time, the resist protective film on the photoresist film is removed. The resist protective film can be removed more easily without increasing the number of layers.

  As described above, the resist protective film material of the present invention contains a polymer compound containing a repeating unit having at least one of an amino group and a sulfonamide group represented by the general formula (1). For this reason, if a protective film is formed on the photoresist film using this, the migration of the amine compound from the photoresist film can be effectively prevented. For example, the surface portion of the photoresist film after development It is possible to more reliably prevent film loss. For this reason, a favorable rectangular resist pattern can be obtained more reliably.

Hereinafter, the present invention will be described in more detail.
When a developer-soluble protective film is formed on a photoresist film, depending on the type of photoresist film, the surface portion of the developed photoresist film may be reduced, and a photoresist film having a resist pattern formed thereon There is a problem that the shape of the top portion of the material becomes round. This is considered to be because the amine compound added to the photoresist film moves to the protective film thereon. For example, when there is a hexafluoroalcohol group in the protective film, since the hexafluoroalcohol group generally has a high affinity with the amine compound, the amine compound added to the photoresist film easily moves to the protective film. Become. As a result, the concentration of the amine compound that prevents acid diffusion near the surface of the photoresist film, that is, near the interface with the protective film is reduced, and the photoresist film portion is dissolved, so that the surface portion of the photoresist film after development is reduced. It is thought that caused.

Therefore, the present inventors considered adding an amine compound in advance in the protective film in order to prevent migration of the amine compound in the photoresist film to the protective film.
However, it has been found that when an amine compound-added top coat is applied, the resist pattern after development may have a T-top shape or the like. This is presumably because the amine compound added to the top coat moved to the photoresist film to form a surface hardly soluble layer. In this case, addition of a weakly basic amine compound is also conceivable. However, since compounds such as carboxylic acid amide, aniline, and pyridine exhibiting weak basicity have strong absorption at a wavelength of 193 nm, this is used as a resist protective film material. When added, there arises a problem that the resist sensitivity is lowered due to absorption.

  Therefore, the present inventors have conceived of adding a polymer-type amine compound as an amine compound that does not move. That is, the resist protective film material contains a polymer compound containing a repeating unit having at least one of a predetermined amino group and sulfonamide group, thereby improving the rectangularity of the resist pattern after development more reliably. As a result, the present invention has been completed.

（上記式中、Ｒ¹は単結合、又は炭素数１〜１０の直鎖状、分岐状又は環状のアルキレン基である。Ｒ²、Ｒ³は、それぞれ独立に、水素原子、炭素数１〜２０の直鎖状、分岐状又は環状のアルキル基、−ＳＯ_２Ｒ^６のいずれかであり、Ｒ^１とＲ^２、Ｒ^１とＲ³、Ｒ²とＲ³のいずれかが、それぞれ結合して環を形成していても良い。Ｒ^６は、炭素数１〜１０の直鎖状、分岐状又は環状のアルキル基であり、アルキル基の水素原子の全部又は一部がフッ素原子で置換されていても良い。） That is, the present invention is a resist protective film material for forming a protective film on a photoresist film, and includes at least one of an amino group and a sulfonamide group represented by the following general formula (1). There is provided a resist protective film material characterized by containing a polymer compound containing a repeating unit.

(In the above formula, R ¹ is a single bond or a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms. R ² and R ³ are each independently a hydrogen atom, Any one of 20 linear, branched or cyclic alkyl groups, —SO ₂ R ⁶ , and any one of R ¹ and R ² , R ¹ and R ³ , R ² and R ³ may be bonded to each other; R ⁶ is a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, and all or part of the hydrogen atoms of the alkyl group are substituted with fluorine atoms. May be.)

（上記式中、Ｒ¹〜Ｒ^３は前述の通りである。Ｒ^４、Ｒ^５は、それぞれ独立に、水素原子、フッ素原子、メチル基、トリフルオロメチル基のいずれかである。Ｘは、−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−Ｒ⁷−Ｃ（＝Ｏ）−Ｏ−、−Ｏ−Ｒ⁷−Ｃ（＝Ｏ）−Ｏ−のいずれかである。Ｒ⁷は、炭素数１〜１０の直鎖状、分岐状又は環状のアルキレン基である。ａ，ｂは、０≦ａ≦０．５、０≦ｂ≦０．５、０＜ａ＋ｂ≦０．５の範囲である。） In this case, the repeating unit having an amino group represented by the general formula (1) in the polymer compound is preferably a repeating unit represented by the following general formula (2).

(In the above formula, R ^{1 to} R ³ are as described above. R ⁴ and R ⁵ are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. X is —O—, —C (═O) —O—, —C (═O) —O—R ⁷ —C (═O) —O—, —O—R ⁷ —C (═O) —O— R ⁷ is a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms, a and b are 0 ≦ a ≦ 0.5, 0 ≦ b ≦ 0.5, 0 <a + b ≦ 0.5.)

Thus, the resist protective film material of this invention contains the high molecular compound containing the repeating unit which has an amino group shown by General formula (1), for example, the repeating unit shown by General formula (2). For this reason, if a protective film is formed on the photoresist film using this, the migration of the amine compound from the photoresist film can be effectively prevented. For example, the surface portion of the photoresist film after development It is possible to more reliably prevent film loss. For this reason, a favorable rectangular resist pattern can be obtained more reliably.
In addition, since an amino group has high hydrophilicity, sliding property may fall by introduction | transduction of an amino group. Therefore, in order to sufficiently prevent a decrease in water slidability, it is preferable that each of R ² and R ^{3 in} the general formula (1) is a tertiary amino group that is not a hydrogen atom, rather than the primary and secondary.

Here, specific examples of the monomer that gives the repeating unit a among the repeating units represented by the general formula (2) include the monomers shown below. In the following formula, R ⁴ is as described above.

  In particular, examples of the monomer that gives the repeating unit a having sulfonamide include those described in JP-A-2005-196209, and specific examples thereof include the monomers shown below.

Moreover, as a monomer which gives the repeating unit b among the repeating units shown by General formula (2), the monomer shown below can be specifically illustrated. In the following formula, R ⁵ is as described above.

In the present invention, the resist protective film material contains a polymer compound containing a repeating unit having one or more of an alkyl group and a fluoroalkyl group (hereinafter referred to as a repeating unit c). preferable.
As described above, if the resist protective film material contains a polymer compound containing the repeating unit c, the water repellency and the water slidability can be further improved by forming a protective film using this. In addition, mixing with the photoresist film can be effectively prevented.

（上記式中、Ｒ^８、Ｒ^１０は、それぞれ独立に、水素原子、フッ素原子、メチル基、トリフルオロメチル基のいずれかである。Ｘ^２は、それぞれ独立に、単結合、−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−Ｒ^１６−Ｃ（＝Ｏ）−Ｏ−のいずれかである。Ｒ^１６は、炭素数１〜１０の直鎖状、分岐状又は環状のアルキレン基であり、アルキレン基の水素原子の全部又は一部がフッ素原子で置換されていても良い。Ｒ^９は、それぞれ独立に、炭素数１〜２０の直鎖状、分岐状又は環状のアルキル基であり、アルキル基の水素原子の全部又は一部がフッ素原子で置換されていても良く、エーテル基、エステル基を有していても良い。Ｒ^１１〜Ｒ^１４は、それぞれ独立に、水素原子、フッ素原子、メチル基、トリフルオロメチル基のいずれかであり、Ｒ^１１〜Ｒ^１４の内、いずれかが少なくとも１個以上のフッ素原子を有する。ｍは、１又は２である。（ｃ−１）、（ｃ−２）、（ｃ−３）、（ｃ−４）、（ｃ−５）は、０≦（ｃ−１）≦０．９、０≦（ｃ−２）≦０．９、０≦（ｃ−３）≦０．９、０≦（ｃ−４）≦０．９、０≦（ｃ−５）≦０．９、０≦（ｃ−１）＋（ｃ−２）＋（ｃ−３）＋（ｃ−４）＋（ｃ−５）≦０．９の範囲である。） In this case, the repeating unit having one or more of an alkyl group and a fluoroalkyl group in the polymer compound may be a repeating unit represented by the following general formula (3).

(In the above formula, R ⁸ and R ¹⁰ are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. X ² is independently a single bond, —O—, Or —C (═O) —O— or —C (═O) —O—R ¹⁶ —C (═O) —O—, wherein R ¹⁶ is a straight chain having 1 to 10 carbon atoms, It is a branched or cyclic alkylene group, and all or part of the hydrogen atoms of the alkylene group may be substituted with fluorine atoms, and each R ⁹ is independently a linear or branched group having 1 to 20 carbon atoms. Or all or part of the hydrogen atoms of the alkyl group may be substituted with fluorine atoms, or may have an ether group or an ester group, R ^{11 to} R ¹⁴ are Each independently of a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. And in either ^{displacement,} .m of R 11 ^{to R 14,} either with at least one fluorine atom is 1 or 2. (C-1), (c-2), (c- 3), (c-4), and (c-5) are 0 ≦ (c-1) ≦ 0.9, 0 ≦ (c-2) ≦ 0.9, 0 ≦ (c-3) ≦ 0. 9, 0 ≦ (c−4) ≦ 0.9, 0 ≦ (c−5) ≦ 0.9, 0 ≦ (c−1) + (c−2) + (c−3) + (c−4) ) + (C-5) ≦ 0.9.)

Here, the monomer for obtaining the repeating unit which has a fluoroalkyl group among the repeating units c can be illustrated below. In the following formula, R ⁸ and R ¹⁰ are as described above.

Moreover, the monomer for obtaining the repeating unit which has an alkyl group among the repeating units c can be illustrated below. In the following formula, R ⁸ and R ¹⁰ are as described above.

Moreover, the monomer for obtaining the repeating unit which has both an alkyl group and a fluoroalkyl group among the repeating units c can be illustrated below. In the following formula, R ⁸ and R ¹⁰ are as described above.

  Further, in the present invention, the resist protective film material preferably contains a polymer compound containing a repeating unit having one or more of a carboxyl group and an α-trifluoromethyl alcohol group.

  Thus, if the resist protective film material contains a polymer compound containing a repeating unit having one or more of a carboxyl group and an α-trifluoromethyl alcohol group, a protective film formed using the same It has high alkali solubility and can be more easily peeled off with an alkaline developer during development. This protective film also has good compatibility with the photoresist film.

（上記式中、Ｒ^１８、Ｒ^２０は、それぞれ独立に、水素原子、フッ素原子、メチル基、トリフルオロメチル基のいずれかである。Ｙは、それぞれ独立に、単結合、−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−Ｒ^２８−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−Ｒ^２８−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−Ｒ^２８−Ｏ−Ｃ（＝Ｏ）−のいずれかである。Ｒ^２８は、炭素数１〜１０の直鎖状、分岐状又は環状のアルキレン基であり、アルキレン基の水素原子の全部又は一部がフッ素原子で置換されていても良い。Ｒ^２６は、それぞれ独立に、単結合、炭素数１〜１０の直鎖状、分岐状又は環状のアルキレン基又はアルカントリイル基のいずれかであり、アルキレン基又はアルカントリイル基の水素原子の全部又は一部がフッ素原子で置換されていても良く、Ｒ^１７は、それぞれ独立に、水素原子、フッ素原子、メチル基、トリフルオロメチル基、ジフルオロメチル基のいずれかであり、Ｒ^２６とＲ^１７は、結合して環を形成していても良く、環の中にエーテル基、水素原子の全部又は一部がフッ素原子で置換されたアルキレン基、トリフルオロメチル基のうち１つ以上の基を有していても良い。ｎは、それぞれ独立に、１又は２である。（ｄ−１）、（ｄ−２）は、０≦（ｄ−１）≦０．９、０≦（ｄ−２）≦０．９、０≦（ｄ−１）＋（ｄ−２）≦０．９の範囲である。） In this case, the repeating unit having an α trifluoromethyl alcohol group (hereinafter referred to as repeating unit d) in the polymer compound is a repeating unit represented by the following general formula (4). it can.

(In the above formula, each of R ¹⁸ and R ²⁰ is independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Y is independently a single bond, —O—, — C (═O) —O—, —C (═O) —O—R ²⁸ —C (═O) —O—, —C (═O) —O—R ²⁸ —O—, —C (═O ) —O—R ²⁸ —O—C (═O) —, wherein R ²⁸ is a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms, and is a hydrogen atom of the alkylene group. R ²⁶ may be each independently a single bond, a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms, or an alkanetriyl group. Any or all of the hydrogen atoms of the alkylene group or alkanetriyl group are substituted with fluorine atoms. May have, R ¹⁷ are each independently a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or a difluoromethyl group, R ²⁶ and R ¹⁷ are linked to form a ring The ring may have one or more groups selected from an ether group, an alkylene group in which all or a part of hydrogen atoms are substituted with fluorine atoms, and a trifluoromethyl group. Each is independently 1 or 2. (d-1) and (d-2) are 0 ≦ (d−1) ≦ 0.9, 0 ≦ (d-2) ≦ 0.9, 0 ≦ ( d-1) + (d-2) ≦ 0.9.

Here, the monomer for obtaining the said repeating unit d can be illustrated below. In the following formulae, R ¹⁸ and R ²⁰ are as described above.

（上記式中、Ｒ^２９は、水素原子、フッ素原子、メチル基、トリフルオロメチル基、−ＣＯＯＨ、−ＣＨ_２−ＣＯＯＨのいずれかである。Ｒ^１９は、水素原子、フッ素原子、メチル基、トリフルオロメチル基、−ＣＯＯＨ、−ＣＨ_２−ＣＯＯＨのいずれかである。Ｙは、それぞれ独立に、単結合、−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−Ｒ^２８−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−Ｒ^２８−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−Ｒ^２８−Ｏ−Ｃ（＝Ｏ）−のいずれかである。Ｒ^２８は、炭素数１〜１０の直鎖状、分岐状又は環状のアルキレン基であり、アルキレン基の水素原子の全部又は一部がフッ素原子で置換されていても良い。Ｒ^２６は、それぞれ独立に、単結合、炭素数１〜１０の直鎖状、分岐状又は環状のアルキレン基又はアルカントリイル基のいずれかであり、アルキレン基又はアルカントリイル基の水素原子の全部又は一部がフッ素原子で置換されていても良い。ｎは、それぞれ独立に、１又は２である。（ｅ−１）、（ｅ−２）は、０≦（ｅ−１）≦０．９、０≦（ｅ−２）≦０．９、０≦（ｅ−１）＋（ｅ−２）≦０．９の範囲である。） In this case, the repeating unit having a carboxyl group in the polymer compound (hereinafter referred to as a repeating unit e) can be a repeating unit represented by the following general formula (5).

(In the above formula, R ²⁹ is any one of a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, —COOH, —CH ₂ —COOH. R ¹⁹ is a hydrogen atom, a fluorine atom, a methyl group, Any one of a trifluoromethyl group, —COOH, and —CH ₂ —COOH, each of Y is independently a single bond, —O—, —C (═O) —O—, —C (═O) —; O—R ²⁸ —C (═O) —O—, —C (═O) —O—R ²⁸ —O—, —C (═O) —O—R ²⁸ —O—C (═O) — R ²⁸ is a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms, and all or part of the hydrogen atoms of the alkylene group may be substituted with fluorine atoms. R ²⁶ independently represents a single bond, a straight, alkylene branched or cyclic Or an alkanetriyl group, and all or part of the hydrogen atoms of the alkylene group or alkanetriyl group may be substituted with fluorine atoms, and n is independently 1 or 2. (E-1) and (e-2) are 0≤ (e-1) ≤0.9, 0≤ (e-2) ≤0.9, 0≤ (e-1) + (e-2) ≦ 0.9.)

Here, the monomer for obtaining the repeating unit e can be illustrated below. In the following formula, R ²⁹ and R ¹⁹ are as described above.

In particular, as a polymer compound to be contained in the resist protective film material, one or more of a repeating unit represented by the general formula (2) (repeating units a and b), an alkyl group that is a water repellent group, and a fluoroalkyl group are included. The repeating unit having the repeating unit (repeating unit c), the repeating unit having the α-trifluoromethyl alcohol group that is an alkali-soluble group (repeating unit d), and the repeating unit having the carboxyl group (repeating unit e) are combined at an appropriate ratio. By using a polymer obtained by polymerization, the dissolution rate in water is 0.1 Å (angstrom) / s or less, and the dissolution rate of a developer composed of a 2.38 mass% tetramethylammonium hydroxide aqueous solution is A resist protective film of 300 Å / s or more can be formed.
Of course, the polymer compounds having the respective repeating units may be copolymerized or blended at an appropriate ratio.

  The ratio of the repeating units a, b, c, d, e is preferably 0 ≦ a ≦ 0.5, 0 ≦ b ≦ 0.5, 0 <a + b ≦ 0.5, 0 ≦ (c−1). ≤0.9, 0≤ (c-2) ≤0.9, 0≤ (c-3) ≤0.9, 0≤ (c-4) ≤0.9, 0≤ (c-5) ≤0 .9, 0 ≦ (c−1) + (c−2) + (c−3) + (c−4) + (c−5) ≦ 0.9, 0 ≦ (d−1) ≦ 0.9 0 ≦ (d−2) ≦ 0.9, 0 ≦ (d−1) + (d−2) ≦ 0.9, 0 ≦ (e−1) ≦ 0.9, 0 ≦ (e−2) ≤0.9, 0≤ (e-1) + (e-2) ≤0.9, a + b + (c-1) + (c-2) + (c-3) + (c-4) + (c -5) + (d-1) + (d-2) + (e-1) + (e-2) = 1.

  More preferably, 0 ≦ a ≦ 0.5, 0 ≦ b ≦ 0.5, 0.005 ≦ a + b ≦ 0.5, 0 ≦ (c-1) ≦ 0.85, 0 ≦ (c-2) ≦ 0.85, 0 ≦ (c−3) ≦ 0.85, 0 ≦ (c−4) ≦ 0.85, 0 ≦ (c−5) ≦ 0.85, 0 ≦ (c−1) + (c -2) + (c-3) + (c-4) + (c-5) ≦ 0.85, 0 ≦ (d−1) ≦ 0.85, 0 ≦ (d-2) ≦ 0.85, 0≤ (d-1) + (d-2) ≤0.85, 0≤ (e-1) ≤0.85, 0≤ (e-2) ≤0.85, 0≤ (e-1) + (E-2) ≦ 0.85, a + b + (c−1) + (c−2) + (c−3) + (c−4) + (c−5) + (d−1) + (d− 2) The range of + (e-1) + (e-2) = 1.

  More preferably, 0 ≦ a ≦ 0.4, 0 ≦ b ≦ 0.4, 0.01 ≦ a + b ≦ 0.4, 0 ≦ (c−1) ≦ 0.85, 0 ≦ (c−2) ≦ 0.85, 0 ≦ (c−3) ≦ 0.85, 0 ≦ (c−4) ≦ 0.85, 0 ≦ (c−5) ≦ 0.85, 0 ≦ (c−1) + (c -2) + (c-3) + (c-4) + (c-5) ≦ 0.85, 0 ≦ (d−1) ≦ 0.85, 0 ≦ (d-2) ≦ 0.85, 0≤ (d-1) + (d-2) ≤0.85, 0≤ (e-1) ≤0.85, 0≤ (e-2) ≤0.85, 0≤ (e-1) + (E-2) ≦ 0.85, a + b + (c−1) + (c−2) + (c−3) + (c−4) + (c−5) + (d−1) + (d− 2) The range of + (e-1) + (e-2) = 1.

  Here, a + b + (c-1) + (c-2) + (c-3) + (c-4) + (c-5) + (d-1) + (d-2) + (e -1) + (e-2) = 1 means that in a polymer compound containing repeating units a, b, c, d, e, the total amount of repeating units a, b, c, d, e is all repeating units. It shows that it is 100 mol% with respect to the total amount.

  The polymer compound contained in the resist protective film material of the present invention has a polystyrene-reduced mass average molecular weight of 1,000 to 500,000, preferably 2,000 to 30,000 by gel permeation chromatography (GPC). It is desirable to be. When the mass average molecular weight is 1,000 or more, there is little possibility of mixing with the photoresist film, and it becomes difficult to dissolve in a liquid such as water. In addition, when the mass average molecular weight is 500,000 or less, there is little risk of problems in film formability after spin coating and the like, and there is little risk of a decrease in alkali solubility.

  In order to synthesize a polymer compound to be contained in the resist protective film material of the present invention, one method includes synthesizing a monomer having an unsaturated bond for obtaining the repeating units a to e in an organic solvent, a radical initiator. In addition, a polymer compound can be synthesized by performing heat polymerization. Examples of the organic solvent used at the time of polymerization include toluene, benzene, tetrahydrofuran, diethyl ether, dioxane, methanol, ethanol, isopropanol and the like. As polymerization initiators, 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis (2,4-dimethylvaleronitrile), dimethyl-2,2-azobis (2-methylpropio) Nate), benzoyl peroxide, lauroyl peroxide, and the like, preferably polymerized by heating to 50 to 80 ° C. The reaction time is 2 to 100 hours, preferably 5 to 20 hours. The fluoroalcohol group at the monomer stage is substituted with an acetyl group or an acetal, and may be converted to a fluoroalcohol by alkali treatment or acid treatment after polymerization.

  The resist protective film material of the present invention preferably further contains a solvent. By using the above-described polymer compound dissolved in a solvent, the film formability can be further improved. In this case, it is preferable to use a solvent so that the concentration of the polymer compound is 0.1 to 20% by mass, particularly 0.5 to 10% by mass, from the viewpoint of film formability by a spin coating method or the like.

  The solvent used is not particularly limited, but a solvent that does not dissolve the photoresist film is preferable. Examples of the solvent for dissolving the photoresist film include ketones such as cyclohexanone and methyl-2-n-amyl ketone used as the resist solvent, 3-methoxybutanol, 3-methyl-3-methoxybutanol, and 1-methoxy-2. -Alcohols such as propanol and 1-ethoxy-2-propanol, ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether and diethylene glycol dimethyl ether, propylene glycol Monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, - methyl methoxypropionate, ethyl 3-ethoxypropionate, acetate tert- butyl, tert- butyl propionate, and esters such as propylene glycol monobutyl -tert- butyl ether acetate.

  Since the photoresist film is not dissolved, examples of the solvent preferably used in the present invention include non-polar solvents such as higher alcohols having 4 or more carbon atoms, toluene, xylene, anisole, hexane, cyclohexane, decane, and ether. In particular, higher alcohols having 4 or more carbon atoms and ethers having 8 to 12 carbon atoms are preferably used. Specifically, 1-butyl alcohol, 2-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2 -Pentanol, 3-pentanol, tert-amyl alcohol, neopentyl alcohol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1-hexanol 2-hexanol, 3-hexanol, 2,3-dimethyl-2-butanol, 3,3-dimethyl-1-butanol, 3,3-dimethyl-2-butanol, 2-diethyl-1-butanol, 2-methyl -1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentano , 3-methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl -3-pentanol, cyclohexanol, diisopropyl ether, diisobutyl ether, diisopentyl ether, di-n-pentyl ether, methylcyclopentyl ether, methylcyclohexyl ether, di-n-butyl ether, di-secbutyl ether, diisopentyl ether , Di-sec-pentyl ether, di-t-amyl ether, di-n-hexyl ether.

On the other hand, since a fluorine-based solvent does not dissolve the photoresist film, it can be preferably used in the present invention.
Examples of such fluorine-substituted solvents include 2-fluoroanisole, 3-fluoroanisole, 4-fluoroanisole, 2,3-difluoroanisole, 2,4-difluoroanisole, 2,5-difluoroanisole, 5, 8-difluoro-1,4-benzodioxane, 2,3-difluorobenzyl alcohol, 1,3-difluoro-2-propanol, 2 ′, 4′-difluoropropiophenone, 2,4-difluorotoluene, trifluoroacetaldehyde Ethyl hemiacetal, trifluoroacetamide, trifluoroethanol, 2,2,2-trifluoroethyl butyrate, ethyl heptafluorobutyrate, ethyl heptafluorobutyl acetate, ethyl hexafluoroglutaryl methyl, ethyl-3-hydroxy 4,4,4-trifluorobutyrate, ethyl-2-methyl-4,4,4-trifluoroacetoacetate, ethyl pentafluorobenzoate, ethyl pentafluoropropionate, ethyl pentafluoropropynyl acetate, ethyl perfluoroocta Noate, ethyl-4,4,4-trifluoroacetoacetate, ethyl-4,4,4-trifluorobutyrate, ethyl-4,4,4-trifluorocrotonate, ethyltrifluorosulfonate, ethyl-3 -(Trifluoromethyl) butyrate, ethyl trifluoropyruvate, S-ethyl trifluoroacetate, fluorocyclohexane, 2,2,3,3,4,4,4-heptafluoro-1-butanol, 1,1,1 , 2,2,3,3-heptafluoro-7,7-dimethyl Til-4,6-octanedione, 1,1,1,3,5,5,5-heptafluoropentane-2,4-dione, 3,3,4,4,5,5,5-heptafluoro- 2-pentanol, 3,3,4,4,5,5,5-heptafluoro-2-pentanone, isopropyl 4,4,4-trifluoroacetoacetate, methyl perfluorodenanoate, methyl perfluoro (2 -Methyl-3-oxahexanoate), methyl perfluorononanoate, methyl perfluorooctanoate, methyl-2,3,3,3-tetrafluoropropionate, methyl trifluoroacetoacetate, 1,1, 1,2,2,6,6,6-octafluoro-2,4-hexanedione, 2,2,3,3,4,4,5,5-octafluoro-1-pentanol, 1H, H, 2H, 2H-perfluoro-1-decanol, perfluoro (2,5-dimethyl-3,6-dioxane anionic) acid methyl ester, 2H-perfluoro-5-methyl-3,6-dioxanonane, 1H 1H, 2H, 3H, 3H-perfluorononane-1,2-diol, 1H, 1H, 9H-perfluoro-1-nonanol, 1H, 1H-perfluorooctanol, 1H, 1H, 2H, 2H-perfluoro Octanol, 2H-perfluoro-5,8,11,14-tetramethyl-3,6,9,12,15-pentaoxaoctadecane, perfluorotributylamine, perfluorotrihexylamine, perfluoro-2,5 8-trimethyl-3,6,9-trioxadodecanoic acid methyl ester, perfluorotripentyl Min, perfluorotripropylamine, 1H, 1H, 2H, 3H, 3H-perfluoroundecane-1,2-diol, trifluorobutanol 1,1,1-trifluoro-5-methyl-2,4-hexanedione 1,1,1-trifluoro-2-propanol, 3,3,3-trifluoro-1-propanol, 1,1,1-trifluoro-2-propyl acetate, perfluorobutyltetrahydrofuran, perfluoro (butyl Tetrahydrofuran), perfluorodecalin, perfluoro (1,2-dimethylcyclohexane), perfluoro (1,3-dimethylcyclohexane), propylene glycol trifluoromethyl ether acetate, propylene glycol methyl ether trifluoromethyl acetate, trifluorome Butyl butyl acetate, methyl 3-trifluoromethoxypropionate, perfluorocyclohexanone, propylene glycol trifluoromethyl ether, butyl trifluoroacetate, 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione 1,1,1,3,3,3-hexafluoro-2-propanol, 1,1,1,3,3,3-hexafluoro-2-methyl-2-propanol, 2,2,3,4 , 4,4-hexafluoro-1-butanol, 2-trifluoromethyl-2-propanol, 2,2,3,3-tetrafluoro-1-propanol, 3,3,3-trifluoro-1-propanol, 4,4,4-trifluoro-1-butanol and the like can be used, and one of these can be used alone or in admixture of two or more. But it is not limited thereto.

Next, a pattern forming method using the resist protective film material of the present invention will be described.
The pattern forming method of the present invention includes at least a step of forming a photoresist film on a substrate, a step of forming a resist protective film on the photoresist film using the resist protective film material of the present invention, It includes a step of exposing and a step of developing using a developer.

First, a photoresist film is formed on the substrate.
Examples of the film forming method include a spin coating method. At this time, in order to reduce the amount of dispensing in the spin coating of the photoresist film material, it is preferable to dispense and spin coat the photoresist film material while the substrate is coated with a photoresist solvent or a solution mixed with the photoresist solvent. (For example, refer to JP-A-9-246173). Thereby, the spread of the solution of the photoresist film material to the substrate is improved, and the dispense amount of the photoresist film material can be reduced.

  The type of the photoresist film material is not particularly limited. It may be a positive type or a negative type, and may be an ordinary hydrocarbon-based single layer resist material or a bilayer resist material containing silicon atoms.

  In the photoresist film material in KrF exposure, a part or all of hydrogen atoms of hydroxy group or carboxyl group of polyhydroxystyrene or polyhydroxystyrene- (meth) acrylate copolymer as a base resin is substituted with an acid labile group. Those containing a polymer are preferably used.

  The photoresist film material in ArF exposure must have a structure that does not contain an aromatic as a base resin. Specifically, polyacrylic acid and derivatives thereof, norbornene derivative-maleic anhydride alternating polymer and polyacrylic acid or Tri- or quaternary copolymers with derivatives thereof, tetracyclododecene derivatives-maleic anhydride alternating polymers and ternary or quaternary copolymers with polyacrylic acid or derivatives thereof, norbornene derivatives-maleimide alternating polymers and poly A ternary or quaternary copolymer with acrylic acid or a derivative thereof, a tetracyclododecene derivative-maleimide alternating polymer and a ternary or quaternary copolymer with polyacrylic acid or a derivative thereof, and two or more of these, Or one or more selected from polynorbornene and metathesis ring-opening polymers Those containing high molecular polymer are preferably used.

Next, a resist protective film is formed on the photoresist film using the resist protective film material of the present invention.
Examples of the film forming method include a spin coating method. In spin coating of resist protective film material, the same process as the above-mentioned photoresist film can be considered. Before applying the resist protective film material, apply the resist protective film material after applying the surface of the photoresist film with a solvent. May be. The thickness of the resist protective film to be formed is preferably in the range of 10 to 500 nm. For coating the surface of the photoresist film with a solvent, a spin coating method or a vapor prime method can be used, but a spin coating method can be used more preferably. The solvent used at this time is more preferably selected from higher alcohols, ether-based and fluorine-based solvents that do not dissolve the aforementioned photoresist film.

  When exposure is performed by immersion lithography as will be described later, the presence / absence of cleaning of the substrate edge and back surface and the cleaning method are important in order to prevent water from flowing into the back surface of the substrate and elution from the substrate. For this reason, for example, it is preferable to volatilize the solvent by forming a resist protective film by spin coating and then baking it at 40 to 130 ° C. for 10 to 300 seconds. In addition, edge cleaning is performed at the time of spin coating in the case of a photoresist film or dry exposure, but in the case of immersion exposure, when a highly hydrophilic substrate surface comes into contact with water, water may remain on the substrate surface of the edge portion. Yes, not preferable. Therefore, there is a method in which edge cleaning is not performed during spin coating of the resist protective film.

Next, exposure is performed.
Examples of the exposure method include dry exposure in which the space between the projection lens and the substrate is a gas such as air or nitrogen.

  However, in the present invention, the exposure process is preferably performed by immersion lithography performed by inserting a liquid between the projection lens and the substrate. Water is preferably used as the liquid inserted between the projection lens and the substrate. The exposure is preferably performed using a light source having an exposure wavelength in the range of 180 to 250 nm, for example, a KrF excimer laser (248 nm) or an ArF excimer laser (193 nm).

Next, development is performed.
In the development step, for example, development is performed with an alkali developer for 10 to 300 seconds. As the alkali developer, a 2.38 mass% tetramethylammonium hydroxide aqueous solution is generally widely used.

  In this case, it is preferable that in the development step, development is performed using an alkaline developer to form a resist pattern on the photoresist film, and at the same time, the resist protective film on the photoresist film is peeled off. In this way, the resist protective film can be peeled off more easily without adding a peeling apparatus to the conventional apparatus.

  Further, post exposure baking (PEB) is preferably performed after exposure and before development. In the case of immersion lithography using water, water may remain on the resist protective film before PEB. If PEB is performed in a state where water remains, water passes through the resist protective film, and the acid in the photoresist film is sucked out, so that a good pattern may not be formed. Therefore, in order to completely remove the water on the resist protective film before PEB, spin drying before PEB, purging with dry air or nitrogen on the surface of the protective film, or the shape of the water recovery nozzle on the stage after exposure or water recovery It is preferable to dry or recover the water on the protective film by optimizing the process. In this case, by improving the water repellency of the resist protective film, the water recoverability is excellent.

  In addition to the above steps, it goes without saying that other various steps such as an etching step, a resist removal step, and a cleaning step may be performed.

EXAMPLES Hereinafter, although an Example, a comparative example, etc. are shown and this invention is demonstrated further more concretely, this invention is not limited by these description.
In the examples, GPC is gel permeation chromatography, and the polystyrene-reduced mass average molecular weight (Mw) and number average molecular weight (Mn) were determined.

Here, structural formulas of monomers 1 to 15 used in the synthesis examples described later are shown below.

(Synthesis Example 1)
To a 200 mL flask, 22.1 g of monomer 4, 6.0 g of monomer 8, 0.8 g of monomer 1 and 40 g of methanol 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, 3 g of 2,2′-azobis (2,4-dimethylvaleronitrile) was added as a polymerization initiator, and the temperature was raised to 65 ° C., followed by reaction for 25 hours. The reaction solution was crystallized from hexane to isolate the resin. The composition of the obtained resin was ¹ H-NMR, the molecular weight was confirmed by GPC, and polymer 1 was obtained.

(Synthesis Example 2)
To a 200 mL flask, 22.1 g of monomer 4, 6.0 g of monomer 8, 1.2 g of monomer 2, and 40 g of methanol 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, 3 g of 2,2′-azobis (2,4-dimethylvaleronitrile) was added as a polymerization initiator, and the temperature was raised to 65 ° C., followed by reaction for 25 hours. The reaction solution was crystallized from hexane to isolate the resin. The composition of the obtained resin was ¹ H-NMR, the molecular weight was confirmed by GPC, and polymer 2 was obtained.

(Synthesis Example 3)
In a 200 mL flask, 23.5 g of monomer 4, 4.9 g of monomer 10, 1.2 g of monomer 2 and 40 g of methanol 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, 3 g of 2,2′-azobis (2,4-dimethylvaleronitrile) was added as a polymerization initiator, and the temperature was raised to 65 ° C., followed by reaction for 25 hours. The reaction solution was crystallized from hexane to isolate the resin. The composition of the obtained resin was ¹ H-NMR, the molecular weight was confirmed by GPC, and polymer 3 was obtained.

(Synthesis Example 4)
In a 200 mL flask, 25.6 g of monomer 5, 8.1 g of monomer 10, 1.2 g of monomer 2 and 20 g of methanol 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, 3 g of 2,2′-azobis (2,4-dimethylvaleronitrile) was added as a polymerization initiator, and the temperature was raised to 85 ° C. and reacted for 25 hours. The reaction solution was crystallized from hexane to isolate the resin. The composition of the obtained resin was ¹ H-NMR, the molecular weight was confirmed by GPC, and polymer 4 was obtained.

(Synthesis Example 5)
To a 200 mL flask, 30.4 g of monomer 14, 1.2 g of monomer 2 and 20 g of methanol 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, 3 g of 2,2′-azobis (2,4-dimethylvaleronitrile) was added as a polymerization initiator, and the temperature was raised to 85 ° C. and reacted for 25 hours. The reaction solution was crystallized from hexane to isolate the resin. The composition of the obtained resin was ¹ H-NMR, the molecular weight was confirmed by GPC, and the polymer 5 was obtained.

(Synthesis Example 6)
In a 200 mL flask, 19.1 g of monomer 4, 0.9 g of methacrylic acid, 8.1 g of monomer 10, 1.2 g of monomer 2, and 40 g of methanol 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, 3 g of 2,2′-azobis (2,4-dimethylvaleronitrile) was added as a polymerization initiator, and the temperature was raised to 65 ° C., followed by reaction for 25 hours. The reaction solution was crystallized from hexane to isolate the resin. The composition of the obtained resin was ¹ H-NMR, the molecular weight was confirmed by GPC, and the polymer 6 was obtained.

(Synthesis Example 7)
To a 200 mL flask, 26.1 g of monomer 6, 9.5 g of monomer 9, 0.9 g of monomer 3 and 40 g of methanol 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, 3 g of 2,2′-azobis (2,4-dimethylvaleronitrile) was added as a polymerization initiator, and the temperature was raised to 65 ° C., followed by reaction for 25 hours. The reaction solution was crystallized from hexane to isolate the resin. The composition of the obtained resin was ¹ H-NMR, the molecular weight was confirmed by GPC, and the polymer 7 was obtained.

(Synthesis Example 8)
To a 200 mL flask, 31.5 g of monomer 7, 10.1 g of monomer 11, 0.9 g of monomer 3, and 20 g of methanol 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, 3 g of 2,2′-azobis (2,4-dimethylvaleronitrile) was added as a polymerization initiator, and the temperature was raised to 85 ° C. and reacted for 25 hours. The reaction solution was crystallized from hexane to isolate the resin. The composition of the obtained resin was ¹ H-NMR, the molecular weight was confirmed by GPC, and the polymer 8 was obtained.

(Synthesis Example 9)
Monomer 4 (19.1 g), monomer 8 (6.0 g), monomer 12 (3.9 g), and methanol (40 g) as a solvent were added to a 200 mL flask. 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, 3 g of 2,2′-azobis (2,4-dimethylvaleronitrile) was added as a polymerization initiator, and the temperature was raised to 65 ° C., followed by reaction for 25 hours. The reaction solution was crystallized from hexane to isolate the resin. The composition of the obtained resin was ¹ H-NMR, the molecular weight was confirmed by GPC, and the polymer 9 was obtained.

(Synthesis Example 10)
Monomer 4 (19.1 g), monomer 8 (6.0 g), monomer 13 (4.7 g), and methanol (40 g) as a solvent were added to a 200 mL flask. 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, 3 g of 2,2′-azobis (2,4-dimethylvaleronitrile) was added as a polymerization initiator, and the temperature was raised to 65 ° C., followed by reaction for 25 hours. The reaction solution was crystallized from hexane to isolate the resin. The composition of the obtained resin was ¹ H-NMR, the molecular weight was confirmed by GPC, and the polymer 10 was obtained.

(Synthesis Example 11)
To a 200 mL flask, 22.0 g of monomer 4, 7.5 g of monomer 8 and 40 g of methanol 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, 3 g of 2,2′-azobis (2,4-dimethylvaleronitrile) was added as a polymerization initiator, and the temperature was raised to 65 ° C., followed by reaction for 25 hours. The reaction solution was crystallized from hexane to isolate the resin. The composition of the obtained resin was ¹ H-NMR, the molecular weight was confirmed by GPC, and the polymer 11 was obtained.

(Synthesis Example 12)
20.8 g of monomer 12, 3.4 g of monomer 15 and 40 g of methanol as a solvent were added to a 200 mL flask. 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, 3 g of 2,2′-azobis (2,4-dimethylvaleronitrile) was added as a polymerization initiator, and the temperature was raised to 65 ° C., followed by reaction for 25 hours. The reaction solution was crystallized from hexane to isolate the resin. The composition of the obtained resin was ¹ H-NMR, the molecular weight was confirmed by GPC, and the polymer 12 was obtained.

(Examples and comparative examples)
Polymers 1 to 12 synthesized in Synthesis Examples 1 to 12 were used as the polymer compound for the resist protective film material.
1.0 g of the polymers 1 to 12 are dissolved in a mixed solvent of 23 g of diisopentyl ether and 2 g of 2-methyl-1-butanol, and filtered through a 0.2 micron size polypropylene filter, respectively. Solutions of -1 to 12 and comparative TC-1) were prepared.

  After spin-coating a resist protective film material solution on a silicon substrate and baking at 100 ° C. for 60 seconds, a 50 nm thick resist protective film (TC-1 to 12, Comparative TC-1) is formed. A. The refractive index of the protective film at a wavelength of 193 nm was determined using spectroscopic ellipsometry manufactured by Woollam. The results are shown in Table 1 below.

  Next, the silicon substrate on which the resist protective film was formed by the above method was rinsed with pure water for 5 minutes, and the film thickness change of the resist protective film before and after rinsing was observed. The results are shown in Table 2 below.

  From Table 2, it can be seen that the resist protective films TC-1 to TC-12 have high water repellency and are difficult to dissolve in water.

  Next, using a silicon substrate on which a resist protective film was formed by the above method, development was performed with an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution, and the film thickness of the resist protective film after development was observed. The results are shown in Table 3 below.

  From Table 3, it can be seen that the resist protective films TC-1 to TC-12 have high alkali solubility and can be easily removed with an alkaline developer during development.

  Next, 50 μL of pure water was dropped onto a silicon substrate that was kept horizontal by forming a resist protective film by the above-described method using a tilt method contact angle meter Drrip Master 500 manufactured by Kyowa Interface Science, thereby forming polka dots. . Next, the silicon substrate was gradually tilted, and the angle (falling angle) and receding contact angle of the silicon substrate at which the polka dots began to fall were obtained. The results are shown in Table 4 below.

  A small falling angle indicates that water easily flows, and a receding contact angle indicates that it is difficult for a droplet to remain even in high-speed scanning exposure. From Table 4, it can be seen that the resist protective films TC-1 to TC-12 are suitable as a resist protective film for immersion lithography because water easily flows and liquid droplets hardly remain even in high-speed scanning exposure. That is, it can be seen that even when the polymer compound containing the repeating unit containing an amino group or the like of the present invention is contained, there is almost no adverse effect on the falling angle and receding contact angle.

  Further, 5 g of resist polymer shown below, 0.25 g of PAG, and 0.05 g of amine quencher were dissolved in 75 g of propylene glycol monoethyl ether acetate (PGMEA) solution, filtered through a 0.2 micron polypropylene filter, A resist film material solution was prepared.

Next, an antireflection film ARC-29A manufactured by Nissan Chemical Industries, Ltd. having a film thickness of 87 nm was formed on the silicon substrate.
Next, a solution of the photoresist film material prepared above was applied onto the substrate on which the antireflection film was formed, and baked at 120 ° C. for 60 seconds to form a 150 nm thick photoresist film.
Next, a resist protective film material prepared in the same manner as described above was applied on the photoresist film, and baked at 100 ° C. for 60 seconds to form a resist protective film (TC-1 to 12, TC-1). .
Next, in order to reproduce the pseudo immersion exposure, pure water rinsing was performed for 5 minutes on the exposed film. That is, it was exposed with a Nikon ArF scanner S307E (NA0.85 σ0.93 4/5 annular illumination, 6% halftone phase shift mask), rinsed for 5 minutes while applying pure water, and post-treated at 110 ° C. for 60 seconds. Exposure bake (PEB) was performed, and development was performed for 60 seconds with a 2.38% by mass TMAH developer.
On the other hand, a process of performing exposure, pure water rinsing, PEB, and development without forming a resist protective film, and a normal process without performing post-exposure pure water rinsing were also performed.
Next, the silicon substrate was cleaved, and the pattern shape and sensitivity of the 75 nm line and space were compared. In addition, the exposure amount which resolves 75 nm line and space by 1: 1 was made into the sensitivity.
The results are shown in Table 5 below.

As shown in Table 5, when post-exposure pure water rinsing was performed without a protective film, a T-top shape was obtained. This is probably because the generated acid was dissolved in water. On the other hand, when the protective film (TC-1 to TC-12) of the present invention was used, the shape change hardly occurred.
On the other hand, in the case of a resist protective film (Comparative TC-1) in which a conventional amino group or the like is not copolymerized, the resist shape after development is reduced.

  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.

Claims (11)

A resist protective film material for forming a protective film on a photoresist film, characterized in that it contains at least a polymer compound containing a repeating unit represented by the following general formula (2) Resist protective film material.

(In the above formula, R ¹ is a single bond or a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms. R ² and R ³ are each independently a hydrogen atom, Any one of 20 linear, branched or cyclic alkyl groups, and any one of R ¹ and R ² , R ¹ and R ³ , R ² and R ³ is bonded to form a ring. R ⁴ and R ⁵ are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, and X is —O—, —C (═O) —O—. , —C (═O) —O—R ⁷ —C (═O) —O—, —O—R ⁷ —C (═O) —O—, wherein R ⁷ is a carbon number of 1 to 10 is a linear, branched or cyclic alkylene group, and a and b are in the range of 0 ≦ a ≦ 0.5, 0 ≦ b ≦ 0.5, and 0 <a + b ≦ 0.5.) The resist protective film material according to claim 1 , wherein the resist protective film material contains a polymer compound containing a repeating unit having one or more of an alkyl group and a fluoroalkyl group. The resist protective film according to claim 2 , wherein the repeating unit having one or more of an alkyl group and a fluoroalkyl group in the polymer compound is a repeating unit represented by the following general formula (3). material.

(In the above formula, R ⁸ and R ¹⁰ are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. X ² is independently a single bond, —O—, Or —C (═O) —O— or —C (═O) —O—R ¹⁶ —C (═O) —O—, wherein R ¹⁶ is a straight chain having 1 to 10 carbon atoms, It is a branched or cyclic alkylene group, and all or part of the hydrogen atoms of the alkylene group may be substituted with fluorine atoms, and each R ⁹ is independently a linear or branched group having 1 to 20 carbon atoms. Or all or part of the hydrogen atoms of the alkyl group may be substituted with fluorine atoms, or may have an ether group or an ester group, R ^{11 to} R ¹⁴ are Each independently of a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. And in either ^{displacement,} .m of R 11 ^{to R 14,} either with at least one fluorine atom is 1 or 2. (C-1), (c-2), (c- 3), (c-4), and (c-5) are 0 ≦ (c-1) ≦ 0.9, 0 ≦ (c-2) ≦ 0.9, 0 ≦ (c-3) ≦ 0. 9, 0 ≦ (c−4) ≦ 0.9, 0 ≦ (c−5) ≦ 0.9, 0 ≦ (c−1) + (c−2) + (c−3) + (c−4) ) + (C-5) ≦ 0.9.) 4. The resist protective film material according to any one of claims 1 to 3 , wherein the resist protective film material contains a polymer compound containing a repeating unit having one or more of a carboxyl group and an α-trifluoromethyl alcohol group. 2. The resist protective film material according to claim 1. The resist protective film material according to claim 4 , wherein the repeating unit having an α-trifluoromethyl alcohol group in the polymer compound is a repeating unit represented by the following general formula (4).

(In the above formula, each of R ¹⁸ and R ²⁰ is independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Y is independently a single bond, —O—, — C (═O) —O—, —C (═O) —O—R ²⁸ —C (═O) —O—, —C (═O) —O—R ²⁸ —O—, —C (═O ) —O—R ²⁸ —O—C (═O) —, wherein R ²⁸ is a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms, and is a hydrogen atom of the alkylene group. R ²⁶ may be each independently a single bond, a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms, or an alkanetriyl group. Any or all of the hydrogen atoms of the alkylene group or alkanetriyl group are substituted with fluorine atoms. May have, R ¹⁷ are each independently a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, or a difluoromethyl group, R ²⁶ and R ¹⁷ are linked to form a ring The ring may have one or more groups selected from an ether group, an alkylene group in which all or a part of hydrogen atoms are substituted with fluorine atoms, and a trifluoromethyl group. Each is independently 1 or 2. (d-1) and (d-2) are 0 ≦ (d−1) ≦ 0.9, 0 ≦ (d-2) ≦ 0.9, 0 ≦ ( d-1) + (d-2) ≦ 0.9. The resist protective film material according to claim 4 or 5 , wherein the repeating unit having a carboxyl group in the polymer compound is a repeating unit represented by the following general formula (5).

(In the above formula, R ²⁹ is any one of a hydrogen atom, a fluorine atom, a methyl group, a trifluoromethyl group, —COOH, —CH ₂ —COOH. R ¹⁹ is a hydrogen atom, a fluorine atom, a methyl group, Any one of a trifluoromethyl group, —COOH, and —CH ₂ —COOH, each of Y is independently a single bond, —O—, —C (═O) —O—, —C (═O) —; O—R ²⁸ —C (═O) —O—, —C (═O) —O—R ²⁸ —O—, —C (═O) —O—R ²⁸ —O—C (═O) — R ²⁸ is a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms, and all or part of the hydrogen atoms of the alkylene group may be substituted with fluorine atoms. R ²⁶ independently represents a single bond, a straight, alkylene branched or cyclic Or an alkanetriyl group, and all or part of the hydrogen atoms of the alkylene group or alkanetriyl group may be substituted with fluorine atoms, and n is independently 1 or 2. (E-1) and (e-2) are 0≤ (e-1) ≤0.9, 0≤ (e-2) ≤0.9, 0≤ (e-1) + (e-2) ≦ 0.9.) The resist protective film material according to any one of claims 1 to 6 , wherein the resist protective film material further contains a solvent. At least a step of forming a photoresist film on the substrate, and a resist protective film is formed on the photoresist film using the resist protective film material according to any one of claims 1 to 7. The pattern formation method characterized by including the process, the process to expose, and the process to develop using a developing solution. 9. The pattern forming method according to claim 8 , wherein the exposure step is performed by immersion lithography performed by inserting a liquid between the projection lens and the substrate. The pattern formation according to claim 9 , wherein the exposure step is performed using water as a liquid inserted between the projection lens and the substrate using a light source having an exposure wavelength in a range of 180 to 250 nm. Method. 11. The developing process according to claim 9 or 10 , wherein in the developing step, development is performed using an alkali developer to form a resist pattern on the photoresist film, and at the same time, the resist protective film on the photoresist film is peeled off. The pattern forming method according to 1.